Search

Speleothem deposits in nowadays arid environments are important climate archives, as they indicate phases of enhanced precipitation and can precisely be dated by uranium-series dating. So far only very few of such archives have been found in the today hyper-arid Saharo-Arabian Desert (SAD). Therefore, the study at hand fills a gap that exists for speleothem climate archives in Northeast Africa. A new record from Saqia Cave (Central Eastern Desert, Egypt) documents for the first-time speleothem growth in Egypt for all sub-stages of MIS 5 and singular phases during MIS 6. Most important growth phases occur during periods of strong increase and maximum orbitally-forced northern hemisphere insolation, but also during phases of low insolation, which are in general attributed to aridity in North Africa. Here, at least semi-arid climate conditions are proposed for periods of low insolation during stadials of MIS 5. This suggests an impact of different possible sources of precipitation, apart from large scale shifts of the African monsoon, such as Red Sea Troughs, tropical plums and a larger spatial extent of the Mediterranean winter-rainfall zone. Concerning the spatial rainfall pattern in Egypt, we propose a considerable east to west rainfall gradient in Egypt for the Last Interglacial and suggest a stronger impact of variable moisture sources in the Eastern Desert near the Mediterranean and Red Sea in comparison to the more continental Western Desert of Egypt. This reveals more favorable pre-conditions for an enhanced land use potential in the past. Therefore, the more sustaining wetter climate in the Eastern Desert point to a recurring feasible dispersal corridor for Homo sapiens from the tropical climate into the temperate climate regime throughout MIS 5. Such a more humid climate provided an ideal basis for long-term, favorable environmental conditions east of the Nile Valley, creating a kind of contiguous landscape corridor that may have been attractive to humans and wildlife alike, linking the East African tropical climate regime with that of the temperate zone in Northeast Africa and Eurasia.

Given the high demand for low-cost housing by the low-income earners, coupled with the tropical climate experienced in sub-Saharan Africa, new-built housing stock needs utmost attention to cost, durability, and efficiency. With the walls accounting for a substantial proportion of the total building cost, choice of a wall system for use in building construction is critical. This choice usually depends on how durable, comfortable, ecological, and economical a given system is, to meet both the quality standards and low-cost aspects of housing. Although the earthbag building system allows for the construction of strong, affordable, and sustainable housing, it is not widely known. As such, its sustainable characteristics have gone unrecognised throughout the building industry. This paper examines and compares the thermal properties and total Life Cycle Costs (LCC) of earthbag walls with the commonly used burnt brick walls - based on the Degree-Days method and Life Cycle Costing analyses of building walls located in one of the hottest regions in Uganda. In-situ measurements of temperature and heat flux were conducted in accordance with ISO 9869 and the annual energy requirements obtained. The total LCC were calculated based on the initial construction costs and annual energy costs attributed to the building wall systems. Earthbags housing was found to be thermal-physically better than the brick wall with a lower U-value resulting in lower annual energy requirements and a huge saving in annual energy costs of up to 83.2%. This saving, coupled with low initial construction costs made the earthbag unit 68.7% cheaper than the burnt brick unit over a 30-year period. Therefore, this study findings suggest earthbag walling system as an economically viable and technically feasible low-cost construction option for rural areas and low-incomers earners’ housing in warm climatic conditions, a characteristic of sub-Saharan countries – so as to promote regional development.

Environmental heat stress in sub-tropical climates negatively impacts boar semen production and its quality. The present study aimed to examine the heat stress alleviating effects of dietary linseed oil on semen quality and antioxidant status of boar, in the summer and winter seasons in sub-tropical climate. Six Hampshire crossbreed boars were fed with 90 mL linseed oil (treatment) whereas six boars of the same breed were fed 90 mL vegetable oil (control) for sixteen weeks during both season. Sperm quality was assessed for motility, viability, abnormality, acrosomal integrity, and Hypo-osmotic swelling test (HOST). Sperm velocity attributes were assessed by computer-assisted semen analysis (CASA). Antioxidants (glutathione peroxidase; GPx, catalase; CAT, total antioxidant capacity; TAC and nitric oxide; NO) and lipid peroxidation (malondialdehyde; MDA) were measured in seminal plasma and serum. Gas chromatography-mass spectrometry (GC-MS) was used for the estimation of fatty acid composition of seminal plasma and spermatozoa. Feeding linseed oil to the boars significantly (p 0.05) improved sperm quality at the fresh stage and after 72 h of liquid storage in both season. There was a significant (p 0.01) effect of treatment and season on semen quality parameters. Significant boar (p 0.05) effect was recorded on reaction time, semen volume, sperm abnormality, acrosomal integrity and HOST reactive sperm. There was a significant (p 0.01) effect of treatment and season on the velocity attributes viz. VAP, VSL, VCL, ALH, BCF and STR%. Linseed oil supplementation significantly (p 0.01) enhanced antioxidant and lowered MDA levels in serum as well as seminal plasma. The concentration of alpha-linolenic (ALA), arachidonic and docosahexaenoic (DHA) fatty acids were significantly (p 0.01) increased in seminal plasma and sperm after linseed oil supplementation. In conclusion, linseed oil supplementation to boar during high THI months improved the semen quality parameters viz. semen volume, sperm concentration, and progressive motile sperm, along with enhanced antioxidant capacity.

Lumefantrine (LMF), a high-mobility and easy-to-crystallize WHO drug for treating malaria, can form an amorphous salt with poly(acrylic acid) (PAA) that is remarkably stable against crystallization at high humidity and temperature and has fast dissolution rate. The amorphous salt up to 75% drug loading was synthesized under a mild slurry condition easily implemented in basic facilities for global health. Salt formation was confirmed by IR spectroscopy and the much elevated glass transition temperature. At 50% drug loading, the amorphous salt resists crystallization for at least 18 months under the highly stressful condition of 40 °C and 75% RH. In contrast, the dispersion containing neutral LMF in PVP fully crystallized in 4 d and the dispersion in HPMCAS, a weak polyelectrolyte of lower charge density than PAA, crystallized by 50% in 7 d. The amorphous salt at 50% drug loading showed much faster dissolution than crystalline LMF: In SGF, the area under the curve (AUC) was 30 times larger within the gastric emptying time (4 h); in FaSSIF, the enhancement was even larger – by 200 times. Nanodroplets were detected during the dissolution in SGF, possibly accounting for the apparent enhancement of dissolution rate. The LMF-PAA example as a challenging case, along with the previously reported clofazimine-PAA, demonstrates the general utility of amorphous drug–polymer salts to achieve high stability under tropical conditions and enhanced dissolution and bioavailability.

This research study presents the experimental assessment of two sensible heat materials originating from the State of Yucatan, Mexico, which were incorporated into three compartments within an indirect type solar dryer with a storage system (ITSD-TSS). The experimental tests were carried out under different environmental conditions and were compared with the results obtained from a conventional solar dryer without thermal storage. Temperature and humidity were measured during the different tests and various indicators were used to compare both drying systems. The results revealed that the solar dryer that used limestone as storage material indicated better performance than the dryer that utilized beach sand, since the drying efficiency with limestone was higher by 1.55% and allowed to extract 0.0257 kg more water per unit kWh. Similarly, beach sand stored 1.5 times more energy than limestone, however, this material is very susceptible to variations of solar radiation, so it is not recommended to implement it in areas with high cloudiness. Finally, the implementation of the three storage compartments in the ITSD-TSS allowed an increase between 3 and 4% of the drying efficiency as compared to the conventional solar dryer. The findings of the work can contribute to sustainable development in the agricultural drying process in rural communities.

Objectives The ACSM recommends drinking to avoid loss of body mass >2% during exercise to avert compromised performance. Our study aimed to assess the level of dehydration in elite runners following a city marathon in a tropical environment. Design Prospective cohort design. Methods Twelve elite runners (6 males, 6 females; age 24–41 y) had body mass measured to the nearest 0.01 kg in their race attire immediately before and after the 2017 Standard Chartered Singapore Marathon 2017. Body mass change was corrected for respiratory water loss, gas exchange, and sweat retained in clothing, and expressed as % of pre-race mass (i.e. % dehydration). Results Data are expressed as means ± SD (range). Dry bulb temperature and humidity were 27.9 ± 0.1 °C (27.4–28.3 °C) and 79 ± 2% (73–82%). Finish time was 155 ± 10 min (143−172 min). Male runners finishing positions ranged from 2–12 out of 7627 finishers, whilst female runners placed 1–8 out of 1754 finishers. Body mass change (loss) and % dehydration for all runners were 2.5 ± 0.5 kg (1.8–3.5 kg) and 4.6 ± 0.9% (3.6–6.8%). Male runners experienced body mass loss of 2.8 ± 0.5 kg and 4.9 ± 1.2% while females experienced body mass loss of 2.1 ± 0.2 kg and 4.3 ± 0.6%. Conclusions Despite experiencing dehydration (4.6% body mass loss) two-fold higher than current fluid replacement guidelines recommend (≤2%), elite male and female runners performed successfully and without medical complication in a hot weather marathon.

This study demonstrates a parametric approach to optimize solar access for high-rise residential buildings in urban tropics. Using parametric modelling, 75 urban contexts were generated for three simulation models characterized as high-rise residential buildings located in an urban tropical climate. In order to optimize solar access in terms of daylight and annual energy savings, this study quantified the shading effects of the urban context, on annual cooling energy, annual daytime lighting energy and spatial daylight autonomy (sDA) for the simulation models. In this study, the optimum solar access is defined for a perimeter zone in a high-rise residential building, achieving 75 sDA (300lx|50) with corresponding annual energy savings of 28%-36% in the east–west and 8%-12% in the north–south directions. As the optimum solar access is difficult to calculate at the early design stage, building setback curves were developed. The prescribed building setbacks were validated with three calibrated case studies. All case studies met 50% of interior spaces (living rooms and bedrooms) with 55 sDA (300lx|50) and annual energy savings of 26%-31% in east–west and 9%-15% in north–south directions. Therefore, the prescribed building setback curves for optimum solar access developed in this study could be applied to high-rise residential buildings between 10 and 31 floors in the tropics.

open access article Component testing indicates that overheating in tropical buildings could be reduced using walls built from upcycled sand-filled plastic bottles, which also reduces building costs and prevents waste from polluting the environment. It is not yet known, however, how these bottle-composite walls influence thermal comfort in dwellings in-situ. This study presents the world's first in-situ measurement of indoor temperature in a “bottle house” which is compared to four other traditional dwellings, two with mud walls and two with sandcrete walls, over a 76-day monitoring period between April and June 2019. Aside from the wall and ceiling construction, the dwellings were otherwise similar in design and located in the same settlement in Abuja, Nigeria. The results showed that on average the bottle house was 2.4 °C cooler than the hottest mud dwelling and 1.8 °C cooler than the hottest sandcrete dwelling. Overheating, determined using the adaptive thermal comfort criteria, occurred in all five dwellings but was lowest in the bottle house. On the day with the highest maximum outdoor temperature (38.2 °C), the bottle house was the coolest dwelling during night time sleeping hours and was 3.4 °C cooler than the hottest mud dwelling during daytime waking hours, although 2.0 °C warmer than the coolest house, which had sandcrete walls. Thus, bottle-composite walls could be a suitable low-cost construction method which contributes to reducing overheating in tropical climates but require additional heat mitigation measures to reduce indoor temperatures to comfortable levels on the hottest days.

The spectral impact on various PV materials –amorphous silicon (a-Si), CdTe, CIGS, single crystalline silicon (sc-Si) and multi crystalline (mc-Si)– in two nearby cities of Southeastern Brazil is presented. For every PV technology studied, the values of the spectral mismatch factor on instantaneous, monthly and annual basis were computed by means of spectra recorded over a 12-month experimental campaign carried out in Sao Paulo and Sao Jose dos Campos. A blue-biased however seasonal spectrum prevails in both cities, which leads to annual spectral gains of up to around 6% and 2% exhibited by a-Si and CdTe, respectively. On the other hand, CIGS, sc-Si and mc-Si show negligible annual gains that lie between around −1% and 0%. These results are well aligned with previous findings obtained using both experimental and modelled spectra in other low-latitude sites with tropical climate. Consequently, spectral effects cannot be ignored in such sites, especially when modelling the outdoor behavior of larger bandgap PV devices. Last, a quasi-linear relationship exists between the monthly average photon energy and the monthly spectral mismatch factor for all the PV materials under scrutiny. This conclusion is in good agreement with previous works carried out in mid-latitude sites.

Based on geographical location, Indonesia is crossed by the equator which has a tropical climate with a high diversity of rainfall. This can lead to an increase or decrease in extreme rainfall that has the potential to cause hydrometeorological disasters such as floods, winds and landslides. Estimation of rainfall is not only influenced by the local topography in each region, but there are also spatial and temporal influences. Therefore, this study aims to estimate the pattern of extreme rainfall and map the rain observer station based on the status of extreme rainfall on spatio-temporal data in the West Java province, Indonesia. Estimator of extreme rainfall patterns uses the generalized linear mixed model (GLMM) which consists of spatial and temporal random components with INLA (integrated nested Laplace approximation) inference. Response data in the form of daily rainfall in 73 observer stations, within 2 years period of observation. Average rainfall data is assumed to have gamma distribution, rainfall above the average is identified using the Bernoulli distribution then identified (extreme) rainfall above average is assumed to have generalized pareto distribution. From the rainfall patterns produced there are a number of conclusions, including that the average rainfall in West Java experiences a consistent downward trend in 13-th week to 32-nd week, which indicates that there is a decrease in rainfall intensity at the beginning of dry season in early April until the end of dry season at the end of August. While in the case of extreme rainfall, the decrease in rainfall intensity consistently occurs from the first week in January to 32-nd week at the end of August. The resulting extreme rainfall mapping states that more extreme rainfall occurs in the north to southeast region of West Java.

Rainfall is one of the climate components which is very important for an agrarian country with a tropical climate like Indonesia. There are so many variables that can affect the intensity of rainfall, including humidity, air temperature, speed and wind direction. However, not all of these variables can have a significant effect, therefore, we need a modeling technique that can select and shrink the predictor variables so as to make the model simpler. One of the techniques used is the Lasso (least absolute shrinkage and selection operator). The purpose of this study is to model rainfall intensity using lasso regression and determine which variable have the greatest influence on rainfall intensity. This paper also designs an application system that can be used to implement Lasso regression. The response variables in the form of daily rainfall at the Citeko observation station, Bogor Indonesia is assumed to have normal distribution. Rainfall intensity modeling involves 16 predictor variables, namely the maximum temperature, minimum temperature, average temperature, average humidity, sun exposure, maximum wind speed, wind direction when maximum wind speed and 8 other categorical variables are the most frequent wind direction. The resulting Lasso regression model successfully select and shrink the variables used to 9 variables only. In addition, based on the AIC and coefficient of determination indices for the model evaluation, the Lasso regression shows satisfying results rather than classical multiple linear regression. In Lasso regression, AIC value is 5901.20 where in classical model it is 5911.43. Also, Lasso regression coefficient of determination value is greater that is 22.73% while in classical model is 21.41%. From lasso regression model that has been obtained, it is known that the most frequent wind direction to the north is the variable that has the greatest influence on rainfall intensity. The Lasso regression application has been successfully created so that it can facilitate the user in uploading data, exploration of data and variables, Lasso regression analysis and report result.

Angkor monuments/temples in the Southeast Asia are UNESCO World Cultural Heritage of the Khmer Civilization and they require preservation and protection from destruction. In this article, activity- and process-based approaches are used to present the current available results on the active microorganisms and their biochemical processes associated with the biodeterioration of sandstone cultural heritage under the tropical climate in Cambodia. Such information is important for effectively protection and management. Severe deterioration of sandstone monuments is a result of weathering processes of a combination of physical, chemical and biological forces, including both natural and anthropogenic ones. Given the fact that water is an important natural factor affecting the stability of sandstone cultural heritage under the tropical regions, subsequent microbial colonization and contribution to the deterioration of sandstone have been investigated with both culture-dependent and culture-independent techniques to provide information about the microbiota associated with the sandstone. Recent data show that both sulfur and nitrogen cycles are active biochemical processes by specific microorganisms on sandstone temples/monuments in the tropical region. Both sulfur-oxidizing bacteria and fungi are active involved and, more recently, ammonia-oxidizing archaea (AOA) are implicated with higher abundance than ammonia-oxidizing bacteria (AOB) on sandstone monuments. It is clear that a research paradigm shift is taking place on microbiology of cultural heritage, and the active, and biochemically and physiologically functional microbes are focused to advance our fundamental understanding and knowledge on the biodeteriogens for a better protection and management of cultural heritage. Biochemically and physiologically functional and important microorganisms, as well as the biochemical mechanisms involved, shall be focused in order to advance the basic research on cultural heritage, while providing essential information for its protection, including Angkor sandstone temples and monuments.

Enhancement of plant diversity via the Janzen-Connell mechanism is often measured relative to neutral models that ignore species' competitive differences. Recent modelling indicates this mechanism is ineffective when included in models incorporating species' demographic variations. This suggests we have been asking the wrong questions when measuring the effectiveness of diversity-enhancing mechanisms.

The grazing of Zebu cattle in poor-quality tropical pastures during the dry season has an increased environmental impact and cost of production. The use of condensed tannins (CT) as a natural feed additive to modulate ruminal archaea can mitigate the methane emissions from cattle in tropical systems. We investigated the effects of CT on in vivo methane emissions and rumen microbiota ecology in beef cattle. Batch experiments were also conducted to evaluate the impact of dietary CT on the biogas production from beef cattle manure. Six adult rumen-cannulated Nellore cattle were used in a double 3 × 3 Latin square design. Treatments consisted of three diets containing either a 0%, 1.25% or 2.5% CT additive from Acacia mimosa extract. The experimental period consisted of 63 days, and methane production was measured using the sulfur hexafluoride (SF6) technique from Day 16 to 21 of each feeding period. Adding Acacia extract to the diets reduced daily methane emissions per animal. Methane suppression occurred more by reduction of intake than by the direct effect on methanogenic archaea. We verified that CT directly suppresses archaea rumen communities and increases total rumen bacteria. Our study indicates that CT benefit rumen Fibrobactersuccinogenes and Ruminoccous flavefaciens populations and have no negative effect on biogas production from cattle manure. Acacia extract as a feed additive has promising potential as part of an overall nutritional strategy to reduce the methanogenesis from Zebu beef cattle in tropical systems.

Tropical insects are astonishingly diverse and abundant yet receive only marginal scientific attention. In natural tropical settings, insects are involved in regulating and supporting ecosystem services including seed dispersal, pollination, organic matter decomposition, nutrient cycling, herbivory, food webs and water quality, which in turn help fulfill UN Sustainable Development Goals (SDGs). Current and future global changes that affect insect diversity and distribution could disrupt key ecosystem services and impose important threats on ecosystems and human well-being. A significant increase in our knowledge of tropical insect roles in ecosystem processes is thus vital to ensure sustainable development on a rapidly changing planet.

Tropical forests now known to be key sites of ancient human occupation and modification from the Late Pleistocene, intensifying into the Late Holocene. Dendrochronology and radiocarbon dating demonstrate that living tropical trees can provide ‘stratigraphic records’ of human influences on growth patterns over the past millennium. Stable isotope analysis of tree rings identify climate-related influences on tree growth, enabling differentiation of natural- versus human-induced forest disturbance. Genetic studies of modern trees can reconstruct impacts of past human activity on the population structure of species that have been deforested (‘selected against’) or promoted (‘selected for’) by humans. Tropical trees are not just key organisms for global climate, biodiversity, and carbon stock but also represent surviving ‘time capsules’ of cultural heritage. After the ice caps, tropical forests are globally the most threatened terrestrial environments. Modern trees are not just witnesses to growing contemporary threats but also legacies of past human activity. Here, we review the use of dendrochronology, radiocarbon analysis, stable isotope analysis, and DNA analysis to examine ancient tree management. These methods exploit the fact that living trees record information on environmental and anthropogenic selective forces during their own and past generations of growth, making trees living archaeological ‘sites’. The applicability of these methods across prehistoric, historic, and industrial periods means they have the potential to detect evolving anthropogenic threats and can be used to set conservation priorities in rapidly vanishing environments.

Exotic plants in semiarid region have developed strategies for efficient use or capture of resources. They have become invasive and outperform native species. To understand which factors could explain the success of invasive woody species in a semiarid region, several physiological traits were analyzed in young plants of two invasive and two native species exposed to different water availability. Invasive plants showed low leaf construction cost, high phosphorus and nitrogen contents, reduced loss of instantaneous energy use efficiency, and smaller specific leaf area when compared to native species. This strategy led to a higher biomass gain and a high root/shoot ratio in both water treatments. After rehydration, invasive plants showed faster recovery and higher rates of CO2 assimilation. This resilience is fundamental for species in semiarid regions, and also increase uptake of nutrients. Maintaining a high photosynthetic rate, whenever there is water availability is a strategy that increases the performance of the species in relation to biomass gain. The low leaf construction cost and the fast recovery of the photosynthetic metabolism of invasive plants after limiting water resources explains the success of these species, and suggests that their potential may increase under prolonged and severe drought seasons.

Constructed wetlands are considered as a promising wastewater treatment option. Though extensively studied, most field experiments reflect the performance of these systems in temperate and cold climates and in relatively controlled flow conditions. This study aims at evaluating the performance of a horizontal subsurface flow constructed wetland using indigenous macrophytes in a tropical climate (i.e., in East Africa, Ethiopia) under suboptimal conditions of flow. Two selected plant species, i.e., Cyperus papyrus (papyrus) and Scirpus validus (bulrush) were tested using the wastewater from a dormitory at Jimma University Campus in Ethiopia. The experimental period consisted of two (rather) well controlled phases with two non-controlled and non-sampled phases and one intentional disturbance phase in between. BOD5 removal was 81% in papyrus, 76% in bulrush and 48% in Control. TSS removal was 76% and 75% in papyrus and bulrush compared to 54% in the control. COD removal showed 65% and 62% in the planted beds and 32% in the control. TSS removal demands more controlled operations than other parameters. It was concluded that CWs can function well under irregular flow conditions and can be the technology of choice in low income countries particularly in tropical climates.

We evaluated the reproductive performance of sows after single fixed-time AI under a tropical climate and investigated the influences of season and insemination technique on the efficacy of single fixed-time AI. After weaning, the sows were divided into CONTROL (n = 212) and FIXED-TIME (n = 212) groups. Sows in the CONTROL group were inseminated at 12 and 36 h after the onset of oestrus, while sows in the FIXED-TIME group were administered 10 μg of GnRH at 72 h after weaning and were inseminated 32 h later. Reproductive performance parameters, including total born, born alive, mummified foetuses and stillborn piglets per litter, piglet birth weight, variation of piglet birth weight within litter, regular return-to-oestrus and farrowing rate, were compared between the two groups. Season was classified into two groups: cool (n = 170) and hot (n = 254), and insemination technique was classified into two groups: conventional AI (n = 171) and intra-uterine insemination (IUI) with a reduced number of spermatozoa (n = 253). On average, regular return-to-oestrus (3.3 vs. 5.6%, P > 0.05) and farrowing rates (92.8 vs. 88.1%, P > 0.05) did not differ between CONTROL and FIXED-TIME groups. However, the total born and born alive piglets per litter in the FIXED-TIME were lower than in the CONTROL group (12.0 vs. 12.8 piglets/litter; P = 0.030 and 11.3 vs. 12.2 piglets/litter, P = 0.007). Interestingly, the number of total born piglets in the FIXED-TIME group was lower than in the CONTROL group only in the sows inseminated in the hot season (11.7 ± 0.32 and 12.9 ± 0.31, respectively, P = 0.005). Piglet birth weight, variation of piglet birth weight within litter, number of piglets at weaning and body weight of piglets at weaning did not differ between groups, irrespective of the season (P > 0.05). The total number of piglets born per litter in the FIXED-TIME group was lower than that in the CONTROL group in sows inseminated via IUI (11.7 ± 0.32 and 12.9 ± 0.32, respectively, P = 0.013), but not in sows inseminated using conventional AI (12.7 ± 0.42 and 12.5 ± 0.41, respectively, P = 0.772). Single fixed-time AI could be successfully performed in sows under a tropical climate, with a promising reproductive performance. However, a decreased litter size at birth after single fixed-time AI was observed when insemination was performed in the hot season. Moreover, single fixed-time AI using IUI with a reduced number of spermatozoa also decreased litter size at birth.

Scientific data come from a domestic rooftop PV plant of 4 kW, located at University of La Réunion (-20.90126, 55.48422), in the South-West of Indian Ocean. The electrical data (voltage and current at AC and DC side, produced power and energy, grid frequency) are collected via the PV system's own operating and management module. Solar irradiance data was measured by a pyranometer in the vicinity of the solar panels and at the same tilt (26°). Ambient and PV module temperature data were measured with two thermocouples. The present dataset includes healthy behaviour and different types of shading faults, identified and labelled by means of a numeric variable. The data streams from each connected device require proper techniques to ensure their persistence. To be able to provide both efficient ingestion and retrieval of these time series collections, the NoSQL database management system InfluxDB has been implemented. The whole dataset can be used for instance for PV modelling, PV plant behaviour analysis, PV production forecasting and PV Fault Detection and Diagnosis (FDD) tool development., This work was supported by the ERDF ("European Regional Development Fund") and the Region Council of La Réunion.

Soil selenium is of great significance to human health. Soil-forming parent rocks are the most critical factor that influences soil Se levels. Chengmai County, Hainan Island, has a tropical climate and diverse types of parent rocks, in which soil Se content is high. This study investigated the vertical distribution of soil Se from various parent rock substrates under tropical climatic conditions, and the factors that influence these soil Se contents, with 69 vertical soil profiles covering Chengmai County. The vertical distribution of soil Se and correlations with CIA (chemical alteration index), Al

The thermal benefits of Vertical Greenery System (VGS) in providing thermal comfort, reducing internal building temperature, and lowering operational energy consumption are not widely known. There is a lack of research and technical knowledge on the effects of vertical greenery systems related to thermal performance, especially in tropical climates, such as that of Malaysia. Therefore, this paper addresses this gap by investigating the effect of VGS on heat transfer and the thermal performance of hypothetical buildings. In this paper, a data prediction method is used to identify the overall thermal transfer value (OTTV) from several hypothetical case studies. A variety of combinations of variables have been used to identify the best design with the lowest OTTV reduction through VGS. From the calculation, Linear Greenery System achieved the highest OTTV reduction with an average of 6.87%, followed by Modular Green Wall (6.82%), Double-skin Green Facades (2.97%), and Direct Green Facades (1.32%). Therefore, this paper can conclude that Linear Green Wall is the best greenery system for reducing heat transfer for the tropical climate of Malaysia.

High atmospheric nitrogen (N) deposition and low soil phosphorus (P) availability occur simultaneously in tropical areas, and thus tropical plants need to adapt nutrient-use strategies to maintain growth and survival. Therefore, identifying the adaptative strategies of tropical plants at different successional stages under low soil P availability is indispensable. Here, we separately investigated foliar traits, photosynthetic characteristics, and P fractions of 8 species in the primary and secondary tropical forests after 10 years of N and P fertilization. P addition increased foliar P concentrations and deceased N:P ratio in the primary forest and secondary forest. The foliar photosynthetic rates did not significantly respond to nutrient additions, and the foliar photosynthetic P-use efficiency (PPUE) reduced under the P addition in the primary forest. In contrast, the foliar photosynthetic rates and photosynthetic nitrogen (N)-use efficiency (PNUE) were enhanced with nutrient additions in the secondary forest. The allocations of foliar nucleic acid P and residual P were reduced by P addition in the primary forest, whereas the allocation of metabolic P was enhanced and the allocation of residual P was reduced by P addition in the secondary forest. Additionally, a higher proportion of structural P was found in the primary forest, and a higher proportion of metabolic P was observed in the secondary forest. Interesting, structural equation model analysis revealed that the plants decreased the allocation of foliar nucleic acid P and increased the allocation of structural P in the primary forest, thereby reducing photosynthetic rates. Whereas the plants enhanced photosynthetic rates by promoting PPUE and the allocation of foliar metabolic P in the secondary forest. Our findings highlighted tropical plants at different successional stages can reasonably allocate foliar P to regulate photosynthetic rates and acclimate to low P environments.

Aboveground carbon storage in forests can be influenced by both structural and compositional diversity of plant communities. However, the relative and interactive effects of structural and compositional diversity on multilevel aboveground carbon storage across forest strata and how these relationships vary with altitude and soil nutrients remain unclear. Using data obtained from 34 tropical forest plots (total area 8.5 ha) in Hainan Island, China, we analyzed the relationships between aboveground carbon at four levels (litter, understory, overstory, and whole-community) with structural diversity (diameter and height diversity) and compositional diversity (species diversity and evenness) in the understory and overstory. The direct and indirect effects of altitude, soil nutrients (total N and total P and N/P ratio), structural diversity, and compositional diversity on aboveground carbon were explored via Bayesian structural equation modeling. The results showed that structural diversity, rather than compositional diversity, in overstory stratum determined aboveground carbon. Specifically, overstory structural diversity was negatively associated with understory carbon, while positively associated with overstory and whole-community carbon. Furthermore, diversity‑carbon relationships were slightly affected by soil nutrients but strongly by altitude. Specifically, the relationship between overstory and whole-community carbon content with overstory tree height diversity weakened with altitude, while their relationship with overstory diameter diversity strengthened. Altitude directly and indirectly affected overstory tree height and diameter diversity through overstory species diversity, thereby reducing understory and increasing overstory and whole-community carbon. Altitude directly promoted litter carbon. We provide evidence that the effects of plant diversity on aboveground carbon storage are forest strata- and altitude-dependent. As overstory structural diversity plays a crucial role in storing aboveground carbon at all altitudes, we proposed that focusing on overstory structural diversity would be promising for predicting trends in how plant diversity affects aboveground carbon in response to climate change.

Summarization: Tannery wastewater is characterized by high and variable concentrations of diverse pollutants, which makes it difficult and costly to treat. In the search for sustainable treatment options for tannery effluents, two pilot-scale horizontal subsurface flow (HSF) constructed wetlands (CW) were built and operated for the treatment of synthetic water of quality similar to that of pre-treated tannery effluents. Five different loading phases were examined with gradual increase of inflow COD, NH4+-N and Cr loads until reaching and exceeding the typical composition of a tannery effluent. High COD and NH4+-N removals were observed (82 and 96%, respectively), and almost complete Cr removal in the outflow, which met the Venezuela national standards for environmental discharge. Plant uptake was measured, but microbial processes appear to be the main ammonium transformation/removal mechanism. Nitrogen, chlorophyll and Cr in the plant aerial parts and roots indicated the capacity of Phragmites sp. to grow and survive even under high loads. The measured heterotrophic bacteria in the substrate and rhizomes indicated the biofilm development and the oxidation of organic matter and nitrogen. Water losses via evapotraspiration were also measured and reached 14%. Overall, the tested CW design proved to be a sustainable and feasible alternative for the treatment of tannery wastewater in tropical climates. Παρουσιάστηκε στο: Chemosphere

Made available in DSpace on 2019-10-04T12:14:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-09-20 Embrapa-Brazilian Agricultural Research Corporation (BIOTEC Network) Universidade Federal do Para (PROPESP) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Pasture-based livestock production is largely centered on monoculture systems that degrade grasslands. In integrated crop-livestock-forestry systems a synergy is supposed to occur between its components, contributing to global food production. Thus, this study aimed to evaluate the effects of the microclimate on integrated crop-livestock-forestry (CLF) and crop-livestock (CL) systems on the behavior and body surface temperatures of beef cattle in a tropical climate. The experiment was carried from December/2016 to June/2017. Adult beef cows were maintained in CL (n = 11) or CLF (n = 12) systems, permanently monitored by automatic weather stations. The microdimatic conditions indicated that CLF was more effective in mitigating the environmental heat load. Animals maintained in CLF showed favorable behavior, longer rumination (42.9 +/- 2.2 vs 36.6 +/- 22 min) and shorter resting time (57.6 +/- 2.7 vs 65.9 +/- 2.8 min) during the morning. The grazing time and other activities did not differ between treatments (P> 0.05) in the afternoon. Animals in CLF exhibited lower surface temperatures of the back (TBack: 31.9 +/- 02 vs 32.8 +/- 02 degrees C, P < 0.05) and of the trunk (TTrunk: 32.0 +/- 0.1 vs 32.5 +/- 0.1 degrees C, P < 0.05) measured by infrared thermography. Animals maintained in CLF showed a significant preferential use of shade and a 23% reduction in the frequency of the animals searching for water troughs. It is evident from the study that integrated crop-livestock-forestry systems can be used to provide a more favorable microclimate within grasslands. Thus, beef cattle benefits from the milder environment and exhibits a higher thermal comfort, which favors food production and the rational use of natural resources. (C) 2019 Elsevier B.V. All rights reserved. Fed Univ Para, Inst Vet Med, Castanhal, PA, Brazil Brazilian Agr Res Corp, Embrapa Southeast Livestock CPPSE Embrapa, Sao Carlos, SP, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Jaboticabal, SP, Brazil Sao Paulo State Univ Julio de Mesquita Filho, Jaboticabal, SP, Brazil Embrapa-Brazilian Agricultural Research Corporation (BIOTEC Network): 01130600105 FAPESP: 2015/26627-5

Given the implications of microplastics contamination in aquatic ecosystems and information scarcity about microplastic abundances in estuarine sediments, this study aimed to quantify and describe the microplastics in the sublittoral sediments from Guanabara Bay. Sediment samples were collected at four sites and three months, microplastics were separated and classified according to type, color, size, and polymer composition. High abundances of microplastic (160 to 1000 items kg−1 or 4367 to 25,794 items m−2) occurred independent of area or period, indicating microplastics are widely spread in Guanabara Bay. The dominant microplastic in the sediment was the translucent polyester microfiber of

Made available in DSpace on 2019-10-06T17:16:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-09-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) The present study evaluated the ecological risk of metal contamination in sediments of Guanabara Bay (GB) by combining multiple lines of evidence (LOEs). Chemical analysis and a set of whole-sediment toxicity assays were conducted with Tiburonella viscana, Kalliapseudes schubartii, Anomalocardia flexuosa, and Nitocra sp. Results were integrated by multivariate analysis and qualitative methods. Additionally, a whole-sediment Toxicity Identification Evaluation technique (TIE) was applied to identify the chemical groups responsible for the effects. Sediments from harbor and industrial areas exhibited toxicity linked to moderate to high concentrations of Zn, Pb, Cu and Cr. The TIE technique confirmed such effects, but it also indicates the contribution of ammonia and organic compounds to the observed toxicity. Our results demonstrate that the combination of multiple LOEs improves the effectiveness of environmental risk assessment of chemical stressors and management of coastal ecosystems in tropical regions. São Paulo State University (UNESP), Praça Infante Dom Henrique, s/n Fluminense Federal University (UFF) Program of Geochemistry Department of Geochemistry West Pará State Federal University (UFOPA) Engineering and Geosciences Institute Mineral Analysis Coordination Center of Mineral Technology (CETEM), Av. Pedro Calmon, 900, Cidade Universitária Rio de Janeiro Federal University (UFRJ) Health Science Center, Av. Carlos Chagas Filho, 373, Cidade Universitária São Paulo State University (UNESP), Praça Infante Dom Henrique, s/n CAPES: 001 FAPESP: 13/15482-0 FAPESP: 2015/13143-0 CNPq: 308533/2018-6 CNPq: 311609/2014-7 CNPq: 455280/2014-2

18 polycyclic aromatic hydrocarbons (PAHs) were evaluated in the Jaguaribe River to explore the influence of grain size, organic carbon, humic and fulvic acids and black carbon on their adsorption onto sediment. The ∑PAHs concentrations variated from 0.6 to 3752.0 ng g−1 with highest concentrations in the estuarine zone. The PAHs predominant source along the river was from mixed sources, mainly related to biomass combustion, small oil spills related to recreational nautical activities and runoff from cities. Organic and inorganic parameters presented influence on PAHs distribution along the river, with humic acid as a determinant factor. These research findings are of importance to an assessment of the fate and transport of PAHs in estuarine systems.

The tribe Urticeae (Urticaceae), popularly known as Nettles, include 12 genera and ca. 200 species, constituting a diverse and cosmopolitan plant clade centered in tropical Asia, Africa, and South America. The global distribution of this clade makes it an excellent group to test hypotheses regarding the processes underlying tropical intercontinental disjunctions. More specifically, it allows us to test whether current distribution patterns resulted from recent transoceanic long-distance dispersal or ancient vicariance after boreotropical migration. We reconstructed the phylogeny of Nettles with the nuclear ITS and four plastid DNA regions (rbcL, trnL-F, matK and rpl14-rpl36) using Bayesian inference and maximum parsimony approaches. We inferred divergence times using a Bayesian uncorrelated lognormal relaxed molecular clock model and ancestral areas using the divergence-extinction-cladogenesis (DEC) model. Our results indicate a tropical Asian origin for the tribe during the late Paleocene. Migration events to Eurasia, South America and Africa occurred mainly during the Oligocene and Miocene. However, several long-distance dispersal events, including dispersals from Asia to Hawaii or Australasia, were inferred to have occurred from the Miocene onwards. The fleshy fruits and winged diaspores of several taxa are suited for long-distance dispersal.

Discharge of municipal wastewater promotes the entry of diverse oestrogenic compounds into the water bodies. This complex mixture of substances interferes in the steroidogenic pathway, being able to promote severe reproductive impairment in freshwater fish populations. The purpose of the present study was to evaluate the effects of oestrogenic endocrine disruptors (EDCs) mixture on gonadal sex steroids (testosterone, T; 11-ketotestosterone, 11-KT; 17β-oestradiol, E2; 17-hydroxyprogesterone, 17-OHP) in the peak of the reproductive season of Astyanax rivularis, correlating the results obtained with the proportion of germ cells and gonadal histopathology. Three sampling sites were chosen to conduct the study, one reference site (S1), without contamination by municipal wastewater and two sites (S2 and S3) receiving discharge of municipal wastewater. Males of A. rivularis presented higher concentrations of E2, lower androgens (T and 11-KT) in gonads when compared to males from site S1. Concentrations of 17-OHP did not present significant difference among sites. In sites S2 and S3, the proportion of early spermatocytes, spermatids and Leydig cells increased while spermatozoa decreased compared to fish from S1. The following gonadal histopathologies were detected in the male fishes: intersex gonads (28% in S3) and testicular degeneration with germinal epithelium exhibiting agglutinated germ cells masses and empty cysts (57% in S2 and 71% in S3). In females, concentrations of T, E2 and 17-OHP did not present significant difference among the sites, however higher 11-KT concentrations were detected in females from sites S2 and S3. A lower proportion of perinucleolar follicles and a higher incidence of vitellogenic follicles, besides, aged oocytes and the presence of eosinophilic proteinaceous fluid in the interstitial compartment were also found in females from impacted sites. These results indicate that the urbanization and consequent release of municipal wastewater containing oestrogenic compounds in the headwater creeks are altering the levels of sex hormones and gametogenesis of A. rivularis. Further studies should be performed to determine whether oestrogenic endocrine disrupters are disrupting the reproduction of A. rivularis.

This study investigated the potential of assessing the water balance in South America, at multiple scales, using satellite remote sensing precipitation and evapotranspiration datasets, terrestrial water storage changes from Gravity Recovery and Climate Experiment (GRACE), and discharge measurements. The remote sensing precipitation datasets included those of the Tropical Rainfall Measuring Mission (TRMM) and the Multi-Source Weighted-Ensemble Precipitation (MSWEP), whilst the ET constituents included the MODIS Global Evapotranspiration Project (MOD16) and the Global Land Evaporation Amsterdam Model (GLEAM). Uncertainties in precipitation and ET were evaluated using in situ measurements of 307 rain-gauge stations and 16 eddy covariance sites, respectively. The water balance closure and uncertainties were evaluated in 50 basins for the period 2003–2014, at different spatial scales and under different climatic conditions. Overall, MSWEP precipitation and GLEAM ET provided fewer uncertainties, whilst TRMM and MOD16 yielded greater bias and more errors. Better agreements between the TWSC from GRACE and the water balance were found in the large and medium-sized basins, with a root mean squared error (RMSE) of about 42%, whilst small basins and those located in regions with subtropical humid climates, where precipitation did not present strong seasonality, had a RMSE around 130%, indicating that climate conditions can influence the water balance closure. The TWSC from GRACE and the remote sensing water balance estimations were in agreement for more than half of the evaluated basins, mainly those located in tropical climate regions. Greater bias and more errors were found in the estimations of discharge in the semi-arid basins, with low runoff coefficients. Despite the water balance based on remote sensing estimations remaining a challenge due to the large uncertainties in precipitation, ET, and TWSC, our results showed their great potential for assessing terrestrial water-cycle dynamics and understanding their spatial and temporal variability at multiple scales.

Vietnam is one of the countries most affected by climate change, but few studies have focused on the population health effects of climate variation. Extreme heatwaves and cold spells might exacerbate underlying chronic conditions and precipitate hospitalization or early death. This study examined the short-term effects of ambient temperature extremes on hospital admissions (HAs) due to acute myocardial infarction (AMI) between different climate zones in the Central Coast region of Vietnam.Information from medical records of all 3328 cases of AMI HAs (with hospital records cross-checked by clinicians) was collected from three hospitals in the South-Central Coast region (tropical savanna climate) and North-Central Coast region (tropical monsoon climate) for the period 2008-2015. Meteorological data were obtained from the National Hydro-Meteorological and Environment Network Centre. We used distributed lag non-linear models to assess the association between daily average temperature and AMI HAs, accounting for long-term trend and other meteorological variables.We found a negative and significant association between AMI HAs and temperature in the North-Central Coast region while conversely there was a positive and significant association in the South-Central Coast region. In the North-Central Coast region, the risk of AMI HAs increased by 11% (Relative risk (RR): 1.11, 95% CI: 0.91-1.35, p 0.05) at moderately low temperatures (10th percentile of temperature range - 18.5 °C) and increased by 25% (RR: 1.25, 95% CI: 1.02-1.55, p 0.05) at extremely low temperatures (5th percentile of temperature range - 16.8 °C). In the South-Central Coast region, the risk of AMI HAs increased by 18% (RR: 1.18, 95% CI: 0.95-1.47, p 0.05) and 36% (RR: 1.36, 95% CI: 1.06-1.73, p 0.05) at moderately high temperatures (90Risk of AMI is associated with extremely high and extremely low temperature in Vietnam and the risk varies in relation to the local regional climate. Public health preparedness and multi-level interventions should attempt to reduce people's exposure in periods of disadvantageous temperatures.

Increasing number of building owners is adopting vertical greenery system (VGS) as an alternative to building facades or claddings due to its environmental, aesthetic and social benefits in recent years. While numerous studies have been conducted on its potential benefits and its environmental impacts, there has been little focus on its life-cycle cost (LCC) which is a crucial factor for building owners to adopt a VGS as well as to compare among various types of system. To fill this gap, this study aims to identify and calculate the LCC of 3 main types of VGS available in Singapore, where is the tropical climate, namely the carrier, planter and support systems. The cost incurred during each life-cycle stage including initialisation, installation, operation and demolition, are recorded based on 8 completed and ongoing cases selected in Singapore. The analysis of the results shows that the support system has the lowest life-cycle cost (S$885) followed by planter (S$3,786) and then the carrier system (S$4,919). During the life-cycle, the stage of Operations and Maintenance contributed the most to the LCC of a VGS (73.7–83.9%), while plants related parameters, e.g. plant replacement rate and price, affect the largest variances of LCC. for the support system, the LCC of VGS can be balanced off by building energy cost savings within 30 years, but not for other two systems. Suggestions on selecting VGS types, plants and supporting structures to reduce the cost of VGS have been discussed to conclude the study.

Indigenous chickens at the Swahili coast and other traditional migratory corridors in Kenya represent important populations that are inconclusively characterized. Using a comprehensive dataset of Kenyan indigenous chickens and additional mined data of chickens from 8 African and 5 Asian countries, we performed univariate and multivariate assessments to uncover the underlying phenotypic and morphometric variability. Kenyan indigenous chickens expressed differentiation of several qualitative and quantitative traits, both among different counties in the Swahili coast, and among coastal, western, and northern migratory corridors. There was a substantial population stratification of these chickens, particularly distinctive clustering of chickens from Marsabit, Lamu, and Kilifi counties. The pooled dataset further clarified a closer phenotypic and morphometric proximity of chickens within different geographical regions. We additionally revealed a preponderance of bantam and rumpless traits to hot and humid locales, and feathered shanks to cooler regions. Currently, most chicken breeding programs in developing countries rely on phenotypic and morphometric properties. Hence, the high chicken diversity and population stratification observed in our study, possibly shaped by natural and artificial selective pressures, reveal opportunities for complementary phenotypic and genotypic assessments to identify resources for effective breed improvement and conservation strategies of indigenous chickens in the tropics.

Methane is a potent greenhouse gas whose atmospheric dispersion may have different implications at distinct scales. One significant contributor to methane emissions is sugarcane farming in tropical areas like in Mexico, which has the sixth highest production level in the world. A consequence of the industrial use of this resource is that sugarcane preharvest burning emits large quantities of methane and other pollutants. The objective of this research is to estimate the methane emissions by sugarcane burning and to analyze their atmospheric dispersion under the influence of meteorological parameters, according to different concentration scenarios generated during a period. The methane emissions were investigated using the methodology of Seiler and Crutzen, based on the stage production during the harvest periods of 2011/2012, 2012/2013 and 2013/2014. Average of total emissions (1.4 × 103 Mg) at the national level was comparable in magnitude to those of other relevant sugarcane-producing countries such as India and Brazil. Satellite images and statistical methods were used to validate the spatial distribution of methane, which was obtained with the WRF model. The results show a dominant wind circulation pattern toward the east in the San Luis Potosi area, to the west in Jalisco, and the north in Tabasco. In the first two areas, wind convergence at a certain height causes a downward flow, preventing methane dispersion. The concentrations in these areas varied from 9.22 × 10−5 to 1.22 × 102 ppmv and 32 × 10−5 to 2.36 × 102 ppmv, respectively. Wind conditions in Tabasco contributed to high dispersion and low concentrations of methane, varying from 8.74 × 105 to 0.33 × 102 ppmv. Methane is a potent greenhouse gas for which it is essential to study and understand their dispersion at different geographic locations and atmospheric conditions.

The role of melatonin in protecting spermatozoa from different kinds of injury has been widely reported. The present study aimed to test whether treatment of buffalo bulls with melatonin could ameliorate sperm function during nonbreeding season under tropical condition. Ten Murrah buffalo bulls were randomly allocated into control and treated groups of equal numbers of bulls to study the effect of melatonin on semen characteristics, seminal plasma constituents, blood plasma hormonal levels, and antioxidant enzyme activities during nonbreeding season. Treated bulls were implanted with melatonin (18 mg/50 kg of body weight) for a period of 2 mo. During this period, semen was collected twice a week, and blood samples were collected weekly to determine plasma concentration of melatonin and LH and activities of antioxidant enzymes. During nonbreeding season, melatonin implantation improved semen characteristics by increasing (P0.05) percentages of sperm with forward motility, viability, total motile sperm, and rapid motility, average path, curvilinear, and straight-line velocity and amplitude of lateral head displacement and decreasing (P0.05) percentages of abnormal sperm and linearity index as compared to the control group. Furthermore, melatonin implantation increased (P0.05) seminal plasma concentrations of total protein, albumin, and cholesterol and decreased (P0.05) seminal plasma aspartate aminotransferase activity. In addition, melatonin-implanted bulls exhibited an increase (P0.05) in red blood cells superoxide dismutase activity compared to untreated bulls. In conclusion, melatonin implantation successfully improved semen quality of buffalo bulls during nonbreeding season under tropical condition.

Land-based sources contribute approximately 80% of anthropogenic debris in marine environments. A main pathway is believed to be rivers and storm-water systems, yet this input is rarely quantified. We aimed to quantify the abundance of land-based debris entering a river system through storm drains in an urban area of tropical Australia. To account for seasonal variability, debris was quantified pre, post and during the wet season from 2014 to 2017. Plastic items within the river were compared to those in adjacent parks to assess similarities in debris composition. A total of 27,943 items were collected (92% plastic). Debris loads in the post-wet seasons were significantly higher than the wet-season. Furthermore, variability in the portion of debris found in nearby parks compared to the river suggests that factors other than rainfall, play a role in debris abundance. These results can be used to identify targeted management strategies to reduce debris loads.

The potential impacts of mining activities on tropical coastal ecosystems are poorly understood. In particular, limited information is available on the effects of metals on scleractinian corals which are foundation species that form vital structural habitats supporting other biota. This study investigated the effects of dissolved nickel and copper on the coral Acropora muricata and its associated microbiota. Corals collected from the Great Barrier Reef were exposed to dissolved nickel (45, 90, 470, 900 and 9050 μg Ni/L) or copper (4, 11, 32 and 65 μg Cu/L) in flow through chambers at the National Sea Simulator, Townsville, Qld, Australia. After a 96-h exposure DNA metabarcoding (16S rDNA and 18S rDNA) was undertaken on all samples to detect changes in the structure of the coral microbiome. The controls remained healthy throughout the study period. After 36 h, bleaching was only observed in corals exposed to 32 and 65 μg Cu/L and very high nickel concentrations (9050 μg Ni/L). At 96 h, significant discolouration of corals was only observed in 470 and 900 μg Ni/L treatments, the highest concentrations tested. While high concentrations of nickel caused bleaching, no changes in the composition of their microbiome communities were observed. In contrast, exposure to copper not only resulted in bleaching, but altered the composition of both the eukaryote and bacterial communities of the coral's microbiomes. Our findings showed that these effects were only evident at relatively high concentrations of nickel and copper, reflecting concentrations observed only in extremely polluted environments. Elevated metal concentrations have the capacity to alter the microbiomes which are inherently linked to coral health.

The complexity of the tropical climate system demands the development of a hierarchy of models to ensure our understanding of its response to anthropogenic forcing. The response of the tropical Pacific Ocean to radiative forcing has been studied previously with a box model. The model has provided insights into the tropical Pacific climate change that are otherwise not easily attainable. But that model only encompasses the tropical Pacific region. Recent studies have also shown that the Indian Ocean (IO) may be important in the response of the Pacific Walker circulation to radiative forcing, raising the need to expand the model to take into account the role of IO. This study presents the results concerning the tropical Pacific response to radiative forcing from an expanded-box model that includes the tropical IO, which influences the tropical Pacific through an inter-basin SST gradient. The three-box model predicts an enhanced zonal SST gradient in tropical Pacific in response to the increased radiative forcing, similar to the previous two-box model. It is further noted that in the three-box model, a warmer IO relative to the Pacific enhances Pacific easterlies and subsequently strengthens the equatorial ocean circulation. Because of this ocean dynamical cooling, the warming response in the Pacific is effectively reduced in the three-box model that includes the role of IO compared with that in the two-box model. The role of the IO warming trend in enhancing the Pacific trade winds is confirmed using an atmospheric general circulation model experiment. These results may help to fully explain the relatively small observed warming trend in the tropical Pacific compared to that in the tropical IO evident in 20th century SST reconstructions.

Nutrients distribution and influencing factors in three seamount areas named Y3, M2 and C4 of the Tropical Western Pacific Ocean (TWPO) were investigated. Nutrients showed obvious uplifts around the three seamounts, consistent with the uplifts of isotherms and isohalines, indicating the existence of a bottom-up process of nutrients. Meanwhile, compared with the stations away from seamount and the reference stations in the TWPO, nutrients concentrations around seamount were much higher. Among the three seamounts, the average nutrients concentrations were highest in Y3, while they were lowest in C4. Moreover, compared with the obvious nitrogen limitation in Y3 and M2, the N:P (13.5:1) and Si:N (6.1:1) were closed to the Redfield ratio. The current-seamount interaction was the determining influencing factor on nutrients distribution, causing the hydrology dynamic changes such as uplifts and Taylor column. Meanwhile, T and S also affected nutrients distribution, especially nutrients and T showed significant negative correlations.

Human bone histological analysis is a useful tool to assess post mortem diagenesis and to predict successful nuclear DNA typing of forensic material. This study is part of a series of studies developed by the authors intended to improve the understanding of post mortem diagenesis and to develop applications for DNA analysis of skeletal species from tropical soils, in order to optimize genetic and anthropological protocols. The aim of this study was to analyze the impact of burial period on the integrity of exhumed compact bone microstructure from tropical climate. In fragments of exhumed human femora from 39 individuals from the same cemetery (exhumed group) and 5 fresh femora from routine autopsies (control group), sections stained by hematoxylin-eosin were analyzed in order to measure bone microstructural integrity. We found that bone integrity index in exhumed group was negatively influenced by the period of burial (r = -0.37, p < 0.05) and highly significantly decreased (p < 0.0001) in comparison to control group. The period of burial and nitric acid decalcification time was positively correlated (r = 0.51; p < 0.01), leading to imply a bone petrification process during inhumation. Exhumed group showed higher level of matrix bone loss (p < 0.001), as expected, and 87% of cases analyzed were "tunneled" as described by Hackett. Bone integrity index and bone matrix tend to decrease in bones buried in tropical soil between 8-14 years of inhumation. This period is short if we consider cases in which there are preserved bones interred for longer periods in other environments. These data must be considered in cases where genetic identification of exhumed skeletons from tropical environment is required. The diagenesis in these bones and the variations of results found are discussed, clarifying some challenges for forensic laboratories, especially in DNA analysis.

Environmental temperatures play a vital role in the physiological and behavioral activity of ectotherms. Behavioral thermoregulation allows animals to modify their body temperature to optimize functions critical to fitness, including digestion, growth, reproduction, and locomotor performance. Diurnal reptiles are a classic model system to answer questions related to thermal ecology, whereas behavioral thermoregulation in nocturnal species is thought to be strongly constrained by low environmental thermal heterogeneity at night. The few studies describing the thermal ecology of nocturnal reptiles indicate a majority of thermoregulatory behavior (if any) occurs during the day within diurnal retreats, but few examined this behavior throughout the night. In tropical systems, thermal heterogeneity may remain high, even at night, allowing nocturnal ectotherms to thermoregulate through conduction on surfaces that retain heat after sunset. We investigated the thermoregulatory behavior of a tropical nocturnal gecko (Australian house gecko, Gehyra dubia) by measuring its preferred temperature in a thermal gradient, and selected body temperatures using radio telemetry, in relation to available operative environmental temperatures obtained using thermal models. Preferred body temperatures of geckos ranged from 31.4 ± 0.59–34.5 ± 0.55 °C in a laboratory thermal gradient. In the field, during winter, geckos were more effective thermoregulators than in the summer. In low thermal quality habitats, geckos sought rare, warm microclimates at night to maintain body temperatures warmer than most available environmental temperatures, and were highly effective thermoregulators. For ectotherms, appropriate environmental temperatures are a vital resource for survival, similar to food or shelter. The ability to exploit rare microclimates is especially important for nocturnal species, as heterogeneity of environmental temperatures is reduced at night compared to the day. In a warming world, it is vital to understand the thermal ecology of nocturnal ectotherms, as other species may shift to become more nocturnal to avoid lethal diurnal temperatures.

In this paper, a shading facade-integrated solar absorber system has been assessed outdoors under the hot tropical climate. The system was developed, and its performance was tested for 79 days under a standard system operating condition. The outdoor field test has demonstrated that the system was principally dependent on the available global irradiance, and its performance was impaired by the high occurrence of afternoon rain. On average, the system was capable to achieve a daily efficiency of 50.5%, maximum daily water temperature attained at 48.9 °C, and solar water heating rate of 2.9 °C/h. Findings showed that the system could perform most frequently at a daily efficiency ranging from 45% to 60%, and the maximum daily water temperature attained from 45 °C to 57 °C during the test period. Empirical results indicate that there exist several linear regressions between the variables that show acceptable correlations. An additional experiment was carried out to assess the heat distribution mapping of the experimental model.

The temperature-humidity index (THI) has been extensively applied for assessing heat stress in moderate to hot conditions in dairy cattle. However, there exist wide variation between researchers in defining an appropriate range of THI values for denoting different levels of stress. The present study was aimed to reassess previously described heat stress indicators of dairy cattle of sub-tropical region of India. From comparative evaluation of meteorological data over previous four years (2014-2017) the period of year when high THI prevailed in the region was determined. Accordingly, the time period of sample collection and observation on animals was decided, so that a THI range of 68-86 could be covered. After analyzing physiological, biochemical parameters and expression profile of heat shock response (HSR) genes of animals in response to different THI, it was evident from the study that animal undergoes few or little changes at THI 72, but major physiological changes occurred after THI reached 74. At THI range 74-79, no drastic change in these parameters occurred suggesting animals undergo transient acclimatization in this range to maintain homeostasis. Once THI reached and crossed 80, this homeostasis was perturbed and animals experienced major physiological changes again. Overall, the study suggests that THI values indicating level of heat stress are dependent on the geographic location, as well as type of animal and therefore, existing THI should be recalibrated for different climatic region for accurate assessment of the heat stress.

This paper establishes the global existence and regularity of solutions to a two-dimensional (2D) tropical climate model (TCM) with fractional dissipation. The inviscid counterpart of this model was derived by Frierson, Majda and Pauluis [8] as a model for tropical geophysical flows. This model reflects the interaction and coupling among the barotropic mode u, the first baroclinic mode v of the velocity and the temperature θ. The systems with fractional dissipation studied here may arise in the modeling of geophysical circumstances. Mathematically these systems allow simultaneous examination of a family of systems with various levels of regularization. The aim here is the global regularity with the least dissipation. We prove two main results: first, the global regularity of the system with ( − Δ ) β v and ( − Δ ) γ θ for β > 1 and β + γ > 3 2 ; and second, the global regularity of the system with ( − Δ ) β v for β > 3 2 . The proofs of these results are not trivial and the requirements on the fractional indices appear to be optimal. The key tools employed here include the maximal regularity for general fractional heat operators, the Littlewood–Paley decomposition and Besov space techniques, lower bounds involving fractional Laplacian and simultaneous estimates of several coupled quantities.

Transportation infrastructures are directly responsible for killing billions of animals worldwide. Although the understanding about road impacts have recently increased, the impact of railroads on wildlife has received less attention. The current knowledge concerning the impacts of railroads focuses mainly on large mammals although amphibians might be affected. Our study aims to unravel temporal and spatial patterns of Rhinella toad fatalities on a Brazilian Amazonian railroad, to comprehend how toads are killed and to estimate the magnitude of toad fatalities. Data collection was carried out on foot on an 871-km stretch of the Estrada de Ferro Carajas from 2013 to 2017. We identified different potential causes for fatalities: being run over, desiccated or with barotrauma signs. We estimated a surprisingly high carcass persistence probability of about 38 days. After correcting for the bias from carcass detection and removal, we estimated that approximately 10,000 toads are killed per year (≈ 11 fatalities/km/year). A GLM model showed that toads were more likely to be killed in the dry to wet transition. We identified critical zones of fatalities and prioritized them according to their intensity. The highly critical segments encompass >10% of all fatalities although they cover only 1.5% of the railroad. Our study is the first one to address carcass detection and persistence on railroads and to unravel patterns of fatalities of an amphibian species in a tropical climate. A better understanding of the patterns of animal fatality on railroads is of fundamental importance to manage and mitigate this impact.

Submarine groundwater discharge (SGD) acts as major pathway to transport solute-laden terrestrial-sourced fresh groundwater, as well as re-circulated marine water to the global oceans. The study area, Bay of Bengal (BoB), a part of the Indian Ocean, receives one of world’s highest terrestrial riverine fresh water discharge, sediment and solute flux from the adjacent Himalayan and cratonic South Asia. Thus, together with the monsoon-dominated tropical climate, it forms one of the most complicated, productive and interactive global hydrological systems. However, understanding such topical phenomena needs intricate mechanistic understanding, based on high resolution data, which are barely available from the BoB. Delineation of stable isotopic and chemical signature of hydrologic-sourced components in the SGD to the BoB would help to identify the intra-annual to diurnal-scale impact of seasonality and tidal cycles, as well as interactions with other surface water bodies. This study provides one of the first documentation of such high-resolution, temporally-variable, stable isotope patterns of SGD in coastal systems of the BoB, and possibly of any tropical ocean. During post-monsoon season, the discharging groundwater was observed to have depleted δ18O (ranges −2.12‰ to −4.19‰) and low Cl− concentrations (745 to >11,500 ppm) (seepage water), which is closely associated with the groundwater δ18O composition (−3.18‰ to −4.05‰) and Cl− content (775 to >5900 ppm) range. In pre-monsoon season depleted δ18O values suggests that regional groundwater contributes up to 45 m from high tide line (HTL) (up to 88%), and re-circulated seawater-sourced SGD dominates 45 m to 110 m (extent of study transect) offshore. In post-monsoon season, terrestrial-sourced groundwater predominates the SGD composition (up to 99%) till 110 m. Changes in δ18O and Cl− content, in pre-monsoon season indicates enhanced infiltration of seawater in the seepage face, due to lower terrestrial-sourced freshwater discharge, whereas, in post-monsoon terrestrial-sourced, resident freshwater dominates in the seepage face. The study suggests that SGD are sourced to interactions between local-regional hydrological systems, and do reflect their compositional variability. It also provides insight of influencing physico-chemical mechanisms, ranging from seasonal to daily-tidal time-scales. The outcome of this study thus may provide intricate insights in delineating the coastal hydrologic and biogeochemical processes, as well as detecting, carbon sinks, nutrient sources and primary productivity in a tropical ocean.

Buildings on tropical islands in the South China Sea are facing an overheating challenge. High-water-absorbency unglazed porous ceramic (UPC) materials could counteract heat gain by evaporation. Salty humid air and seawater in the marine environment lead to evaporative cooling differences from inland conditions. This research replicated a salty humid atmosphere with a stable concentration similar to the actual environment in a dynamic hot-humid climate wind tunnel (DHWT). The influence of salt in gas-liquid media on evaporative cooling is discussed. The results showed that the salt concentration of humid air in the wind tunnel can be controlled by adjusting the atomization rate and the concentration of the atomized liquid. Humid air and liquid with salt reduced the evaporation rate of the UPC tiles. The influence of salty humid air was generally less than that of seawater. In 6 mg/m3 salty air, the total evaporative cooling effect decreased by 2.63% and 40.44% when saturated with fresh water and a 3.5% sodium chloride solution, respectively, relative to saturation with fresh water and evaporation in humid air without salt. In conclusion, sea salt in humid air and in the liquid phase reduced but did not eliminate the evaporative cooling effect of UPC materials. Seawater source utilization showed a significant benefit in cooling and water conservation aspects in coastal areas.

This study investigated exposure to gastrointestinal (GI) nematodes on dairy cattle farms by antibody level determination in bulk tank milk (BTM) samples and its influence on production to detect the risk factors for infection in different climate regions in three states of Mexico. From January to April 2017, BTM samples were collected from 1058 dairy cattle herds and used to establish three Koppen climate classes (tropical, dry and temperate) and states of Mexico. A questionnaire on farm management was applied. The overall herd prevalence of parasites was 67.20%. The highest percentage of positive herds was detected in Veracruz state (78.45%). In addition, the highest prevalence among the climate regions was found in the tropical climate (78.59%). In general, production losses were approximately 1.37–1.78 kg of milk/cow per day. The annual costs of milk production losses per farm were estimated for three different climate regions, ranging between $5541.49 and 6982.50 US$, and those in the three states varied between 5974.10 and 8660.06 US$. The costs for anthelmintic treatments for young stock and adult cows ranged between 57.51 and 192.75 US$, respectively, among the three climate regions and between 46.02 and 189.49 US$, respectively, among the three states. The overall annual costs of milk yield loss per cow were estimated to be 150.74 US$ for the climate regions and 190.54 US$ for the three states of Mexico, followed by the treatment costs for young stock (4.02 US$) and adult cows (3.99 US$). The results suggest that the economic losses due to GI nematodes in Mexican dairy herds are approximately 248 million US$ per annum. Four final models were built based on multivariate logistic regression for potential statistical association from the ELISA results using climatic/environmental and management factors so that each model used different risk factors that were significantly associated with helminth infections in dairy herds.