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The present research is an attempt to screen five perennial indigenous grass species for their biochemical constituents seasonally for one year in order to determine the exact season for the harvest of the target species which will be used as feed ingredient. Among them, Cynodon dactylon has shown better result compared to other grass species and was hence incorporated as micronutrient in the formulated feed. Macrobrachium rosenbergii culture was carried out by feeding conventional and formulated feed (prepared from grass species) in tanks and ponds filled with spring water for 180 days in 2020 in the Eastern Ghats region of Koraput district, Odisha, India. Two treatments namely T1 and T2 having four replications each were supplied with commercial feed and formulated feed. Feeds were applied as per the body weight of prawns at 20% for the 1st month, 15% for the 2nd month, 10% for the 3rd and the 4th month, 5% for the 5th month and 2% till the end of the experiment. The water temperature, pH, dissolved oxygen, transparency, nitrate, phosphate, silicate, Chl a in the culture tanks and ponds were monitored fortnightly. ANOVA results between all the water parameters for both culture tanks and ponds showed significant variation (P < 0.05). The survival rate (77.0% ± 0.89%), daily growth rate (0.233 ± 0.05) g/day, specific growth rate (4.657% ± 1.04%) per day and condition index (2.638 ± 0.05) were found to be highest in prawns fed formulated feed. The feed conversion ratio varied from (2.03 ± 0.05) to (2.68 ± 0.04). Benefit cost ratio of field culture were 1.46 with yield of 702 kg/ha in conventional feed and 1.75 with yield of 950 kg/ha in formulated feed respectively. The study proved grass extracts to be efficient micronutrients for prawn feed which can be easily adopted in prawn production. [ABSTRACT FROM AUTHOR]

The oyster Striostrea prismatica is a fishery-relevant species in the eastern tropical Pacific, particularly in the Mexican Central Pacific (MCP), and little is known about its reproductive cycle. Therefore, our study analysed gametogenesis, sex ratio, sexual maturity stages, shell height at first maturity, and condition index during 2014 and 2015 in El Tizate and La Victoria in the MCP. The sex ratio was significantly biased towards males at both sites, presumably due to ontogeny or fishing pressure. The highest condition index was observed between April and May in both years, while lower values were observed from September to December. The reproductive cycle in both sites was annual, with maturity and spawning from June to August and the degradation phase in August. The condition index showed a negative correlation with temperature and chlorophyll a in both sites: as a result, the period of maximum maturity and spawning coincided with the closure of the fishery in Mexico (June-August). Females had more significant shell height at first maturity than males at both sites, possibly associated with fishing pressure. The information from this study is a significant contribution, but it is necessary to extend the studies to populations further south and further north. [ABSTRACT FROM AUTHOR]

This paper presents a maintenance prioritisation framework for Taiwan's 1268 pedestrian bridges. It aims to standardise their inspection and maintenance, as Taiwan's current bridge management specifications and manuals only apply to its highway and railway bridge infrastructure. It is designed to assess the structural safety and serviceability of six pedestrian bridge types by visual inspection. To assign weight factors to the structural safety and serviceability components of the identified bridge types, two rounds of Delphi method interviews with bridge experts were conducted. The framework is centred on a weighted average condition assessment method that integrates expert-determined weight factors with visual inspection results to calculate a condition index (PBCI). Pedestrian bridges are ranked and classified based on their PBCIs to set appropriate inspection frequency and scope, and to inform maintenance resource allocation. The application of the framework to five pedestrian bridges in Taoyuan City demonstrated its practicality and value for bridge authorities tasked with managing large inventories of pedestrian bridges. [ABSTRACT FROM AUTHOR]

The present study provides length-weight relationships (LWRs) and condition factors (Kn) estimates for ten deep-sea scorpaeniform fishes based on data consisting of new maximum size. The samples were collected from Sakthikulangara Harbour, located on the southwest coast of India, from September 2021 to December 2022. These samples were obtained as bycatch from deep-sea shrimp trawlers operating in the Arabian Sea at depths ranging from 200 to 420 m. The estimated b values ranged from 2.92 (Brachypterois serrulata) to 3.76 (Pterygotrigla arabica). The Kn ranged from 0.56 (Satyrichthys laticeps) to 1.53 (Neomerinthe erostris), with four species exhibiting Kn values higher than 1. The LWR estimates and Kn provided in this study are helpful to understand the growth characteristics of these data limited species and also to revalidate the modeled growth parameters using the Bayesian approach. [ABSTRACT FROM AUTHOR]

The present research is an attempt to screen five perennial indigenous grass species for their biochemical constituents seasonally for one year in order to determine the exact season for the harvest of the target species which will be used as feed ingredient. Among them, Cynodon dactylon has shown better result compared to other grass species and was hence incorporated as micronutrient in the formulated feed. Macrobrachium rosenbergii culture was carried out by feeding conventional and formulated feed (prepared from grass species) in tanks and ponds filled with spring water for 180 days in 2020 in the Eastern Ghats region of Koraput district, Odisha, India. Two treatments namely T1 and T2 having four replications each were supplied with commercial feed and formulated feed. Feeds were applied as per the body weight of prawns at 20% for the 1st month, 15% for the 2nd month, 10% for the 3rd and the 4th month, 5% for the 5th month and 2% till the end of the experiment. The water temperature, pH, dissolved oxygen, transparency, nitrate, phosphate, silicate, Chl a in the culture tanks and ponds were monitored fortnightly. ANOVA results between all the water parameters for both culture tanks and ponds showed significant variation (P

Pavement infrastructure is vital in providing services and links between various sectors of society. Therefore, the preservation and maintenance of these roads are critical to attaining a pavement network in good condition throughout its service life. Various performance indicators like the international roughness index (IRI), pavement condition index (PCI), and present serviceability rating (PSR) have been used by the state department of transportation (DOT) and highway agencies for evaluating pavement surface conditions and planning future maintenance strategies. Limited data availability, multiple distresses depending on region, lack of correlation of these condition indices to maintenance strategies, and data collection limitations pose a challenge for applying these indices to local conditions. This paper compares condition indices of different states for rigid pavements. Further, using a specific condition index for local conditions is also highlighted. For this purpose, five states and their corresponding condition indices were evaluated and compared to the Michigan DOT distress index (DI). These states include Virginia, Minnesota, North Dakota, Louisiana, and Oregon. The corresponding distresses of each condition index were converted to make them compatible with the MDOT DI. This study used the MDOT's pavement management system (PMS) database to evaluate each condition index for 433 rigid pavement sections. Each distress index was plotted against MDOT DI and compared using a paired t-test. Results show that the condition indices of Virginia and Minnesota are comparable to DI in terms of the Spearman correlation value. The t-test results show that except for Virgina, condition indices from other states statistically differ from DI. Therefore, one can't use those directly for local conditions in Michigan. This paper presents the evaluation and data requirements for each condition index and its impact on selecting a maintenance treatment.

We investigated the annual gametogenic development of the Asiatic hard clam, Meretrix meretrix, collected from the west coast of Moheshkhali Island, Cox's Bazar, Bangladesh, by using biometry and histology through monthly sampling from July 2018 to June 2019. After biometric measurements, cross sections were cut for histology to determine the sex and gonadal maturity of the clams. Condition index (CI) showed two distinct peaks in July and December, which indicated that clams were ripe during these months, and a subsequent decrease in CI reflected spawning, which was consistent with histology. Our study revealed a biannual spawning cycle of the clams and gametogenesis starting in October and June. Spawning occurred from February to May and July to September. Maturity index (MI) showed two distinct peaks in July (3.50) and January (3.60) when most of the clams were in late developing or ripe stages. A gradual increase in temperature from annual minima in conjunction with decreasing salinity levels may trigger spawning in February, but spawning in July was initiated when salinity levels increased from annual minima. The data could be used by resource managers for the conservation of this commercial species and to time harvesting for the best quality clams without interrupting spawning activity. [ABSTRACT FROM AUTHOR]

This study provides a comparative analysis of the population dynamics and growth parameters of Mytilus galloprovincialis, based on monthly monitoring in three natural beds along the Moroccan Atlantic coast south of Agadir: Sidi R'bat, Douira, and Tifnit. Conducted over two years, from January 2018 to December 2019, the research aimed to assess the impact of mussel harvesting on their spatial distribution and ecological sustainability. Parameters were determined from size frequencies using FiSAT II software (FAO-ICLARM Stock Assessment Tools). Results showed significant variations in density, biomass, and condition index across all three sites, influenced by environmental and physicochemical factors, as well as the life cycle of the mussels. Douira exhibited the highest levels in the first year. Size class frequency distributions revealed slight differences among stations, with recruitment occurring throughout the study, peaking in winter-spring and summer. The growth rate, measured using the von Bertalanffy equation, was K = 0.5 yr-1 at all sites, with maximum asymptotic length (L∞) and growth performance index (Φ') at Tifnit, recorded at 112mm and 3.7, respectively. Mortality rates (total mortality Z, natural mortality M, fishing mortality F) and exploitation rate (E) were at their highest at Douira (Z = 2.84 yr-1, M = 0.87 yr-1, F = 3.45 yr-1, E = 0.81 yr-1), resulting in a low survival rate (S = 0.014 yr-1). The findings underscore the importance of sustainable management practices by local communities and cooperatives to ensure ecosystem sustainability and product quality. [ABSTRACT FROM AUTHOR]

Pavement infrastructure is vital in providing services and links between various sectors of society. Therefore, the preservation and maintenance of these roads are critical to attaining a pavement network in good condition throughout its service life. Various performance indicators like the international roughness index (IRI), pavement condition index (PCI), and present serviceability rating (PSR) have been used by the state department of transportation (DOT) and highway agencies for evaluating pavement surface conditions and planning future maintenance strategies. Limited data availability, multiple distresses depending on region, lack of correlation of these condition indices to maintenance strategies, and data collection limitations pose a challenge for applying these indices to local conditions. This paper compares condition indices of different states for rigid pavements. Further, using a specific condition index for local conditions is also highlighted. For this purpose, five states and their corresponding condition indices were evaluated and compared to the Michigan DOT distress index (DI). These states include Virginia, Minnesota, North Dakota, Louisiana, and Oregon. The corresponding distresses of each condition index were converted to make them compatible with the MDOT DI. This study used the MDOT's pavement management system (PMS) database to evaluate each condition index for 433 rigid pavement sections. Each distress index was plotted against MDOT DI and compared using a paired t-test. Results show that the condition indices of Virginia and Minnesota are comparable to DI in terms of the Spearman correlation value. The t-test results show that except for Virgina, condition indices from other states statistically differ from DI. Therefore, one can't use those directly for local conditions in Michigan. This paper presents the evaluation and data requirements for each condition index and its impact on selecting a maintenance treatment. [ABSTRACT FROM AUTHOR]

Striostrea prismatica is an oyster of commercial importance present in several locations of the Eastern Tropical Pacific. The objective of this study was to evaluate the sex ratio, gametogenic cycle, maturity stages, size at first maturity (SH50) and monthly variation in the condition index of this species over the course of an annual cycle on the coast of Colima, Mexico. The oysters found in the shallow sublittoral areas near Faro de Campos were larger and heavier than those in Cuyutlan lagoon. The sex ratio was significantly shifted towards males at both sites. The gonad showed a prolonged undifferentiated stage lasting from November to April, a spawning period limited to June through October and an extended post-spawning period from August to December. SH50 was higher in females in the lagoon as well as in the shallow sublittoral. Monthly variation in surface temperature and chlorophyll a in both study areas only correlated with the condition index of populations in the shallow sublittoral and inner lagoon in the months of lowest temperatures and highest chlorophyll a. These findings provide basic information on the reproductive cycle of rock oysters that may prove useful for the development of improved harvesting practices in the study region. [ABSTRACT FROM AUTHOR]

Crassostrea (Magallana) saidii has been commercially ranched in Malaysia and consumed for more than 160 years, but it was only recently identified as a new species to science. This study was conducted to evaluate the reproductive phenology of C. (M.) saidii. Samples of 30 individual oysters were taken monthly for 15 months from the sole population at Sungai Muar estuary in Johor, Malaysia. The sex ratio was 1:1.64 (male:female) for all examined specimens, with female numbers significantly higher. Hermaphrodism was detected in 1.56% of all samples. Spawning peaks in April (2019) and November (2018 and 2019), and were positively associated with the increased rainfall upstream. Gametogenesis occurred throughout the research period with temporal variations. The highest values of maturity index (MI) were recorded in March, August and October 2019, when most oysters were in matured and maturing stages. Condition index (CI) ranged from 31.90 ± 1.25 (April 2019) to 70.03 ± 3.23 (October 2019), exhibiting two peaks (March and October 2019) and subsequently reduced in CI indicating spawning consistency with histological observations. Anthropogenic stressors such as heavy sedimentation and inland development are threatening the survival of this species. The understanding of their reproductive biology is essential to ensure the survival and sustainability of C. (M.) saidii fishery. [ABSTRACT FROM AUTHOR]

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This study reports the gametogenic cycle and condition index (CI) of blood cockle, Tegillarca granosa (L., 1758), by applying biometry and histology of monthly samples obtained from the west coast of Moheshkhali Island, Cox’s Bazar, Bangladesh, over a year. Histology revealed gametogenic activity of T. granosa around the year in the habitat. Pattern of gametogenesis, maturation, spawning, and resorption were similar in males and females with the sexes displaying similar temporal pattern of spawning activity. The initiation of gametogenesis of T. granosa started in September, December, and May in the habitat. Over a 12-month study period, T. granosa exhibited a protracted spawning period from August to April with two major pulses timing September to December and March. CIs as the ratio of tissue wet weight to shell length varied from 1.24 to 3.36 with two distinct peak periods timing August 2018 (1.62 ± 0.42) and June 2019 (2.58 ± 0.48). CIs closely followed the gametogenic cycle of the species. Monthly changes in CIs and spawning season determined from histology suggest that harvesting of T. granosa from the west coast of Moheshkhali, Cox’s Bazar could be economically feasible during June without interrupting the spawning of the species. Pearson correlation analysis indicated a weak correlation between maturity index and environmental variables, as well as CI and environmental variables. Further study is needed on the timing of spatfall of T. granosa in the habitat based on spawning season confirmed in the current study for the collection of spats to supply seeds for commercial farming. [ABSTRACT FROM AUTHOR]

Road structures undergo a series of chemical and physical processes once they are put into service. This phenomenon results from the action of the load and the influence of the environment, which causes their progressive deterioration. In order to mitigate the risk of progressive deterioration and guarantee their stability and durability, various maintenance tasks are required, including visual inspections. The Intelligent Bridge Management System of Colombia (SIGP) includes visual inspection as one of its modules. The system has been designed based on state-of-the-art criteria and national experience with relevant damages and bridge collapses. This paper presents the visual inspection methodology, which includes several stages such as a classification scale, condition index, evaluation areas, damage catalog, and evaluation criteria. In addition, a digital application has been developed to facilitate real-time data collection during field inspections using mobile devices, which can be uploaded directly to the system database hosted in the cloud. The results from the inspection of bridges of different typologies and years of construction are presented, as well as general inspection results from 150 bridges in Colombia. The relevance, comprehensiveness, and accuracy of the inspection are supported by a damage catalog, which allows the identification of intervention needs and reduces the bias of the collected data. [ABSTRACT FROM AUTHOR]

Population of clams Donax trunculus and Chamelea gallina have been declining significantly in recent decades, and environmental pollution and accelerated global warming have been proposed as contributing factors to this decline, in addition to overfishing. Lysosomal membrane stability (LMS) is a sensitive indicator of health status of the organisms. In this study, we investigate the LMS in these species after exposure for 21 days to nine combined conditions of water temperature (12, 20, and 27.5 °C) and salinity ranges (27–28, 32–33, and 37–38). LMS was assessed in living hemocytes by using the neutral red retention assay. Mortality and the condition index of the organisms were evaluated as supporting parameters. The results indicated interspecies differences in the LMS under similar environmental conditions. Overall, LMS was found to be more sensitive to temperature than to salinity changes. Although both species can tolerate changes in either salinity or temperature seawater conditions, the tolerance range is narrower for D. trunculus, showing a significant cytotoxicity (NRRT < 50 min) at temperatures above 27.5 °C and salinities above 32, and 100% mortality at 27.5 °C and a low salinity range (27–28). This study is the first to assess the combined effect of temperature and salinity on the LMS in C. gallina and D. trunculus, and provide necessary information before using LMS as contaminant-related biomarker in field studies with these species. [ABSTRACT FROM AUTHOR]

Information on glochidia larval occurrence and release time from the brooding mussels are crucial for the development of larval rearing system or commercial collection of juveniles from the wilds. We report monthly changes in glochidia larval occurrence and condition index (CI) in freshwater mussel, Lamellidens marginalis, collected from a wetland in Bangladesh. Specimens were drawn monthly over a year from October 2021 to September 2022. Lamellidens marginalis females displayed glochidia larvae in the supra-branchial chamber over ten months from March to December. No glochidia larva was reported in females during January and February when the water temperature remained below 18°C. All females carried glochidia larvae during March and April, indicating no larval shedding at this time. The percentage of females containing glochidia larvae dropped suddenly in May (22.22%), suggesting that glochidial release from the gill chamber to the environment was initiated by May. Larval presence in only some females (22% to 86%) at each sampling date from May to September implied an extended glochidial discharge period till September when the water temperature was above 24°C. The CIs varied from 0.36 to 0.79, with two distinct peaks in December and March when all females carried glochidia larvae. In conclusion, monthly changes in larval occurrence and discharge could be primarily related to temperature and the existence of larvae in mussels could affect the CIs in L. marginalis.

This study investigated the effect of heavy metals on the pearl oyster Pinctada radiata from 5 sites along the coast of Alexandria, with focus on its ecological health and potential risks to human consumption. Pollution results showed that Abu-Qir had the highest Cu and Cd values. Montaza and Eastern Harbor had the highest Fe and Pb values, respectively. Statistically, differences in metal concentrations among study sites were significant (p < 0.05). Non-carcinogenic risk (TTHQ) of tested metals and carcinogenic ones of Cd and Pb showed "high risk" on human health by consuming pearl oysters. Morphometric measurements and condition indices were studied to assess growth patterns and health in relation to heavy metals exposure. Key findings showed detectable declines in size and condition index in Eastern Harbor, whereas Abu-Qir recorded the highest values. This condition index performance presented Abu-Qir, Mammora, and Miami as ideal locations for spat collection and oyster rearing, potentially enhancing Egyptian pearl farming. Average values of spatial proximate contents of pearl oyster showed that it was rich in proteins (33.07–58.52%) with low fat content (1.39–1.87%) and carbohydrates (9.72–17.63%). Biochemical composition of pearl oyster demonstrated its high nutritional value which supported its promotion as a functional food for human consumption. The calorie content of pearl oyster was less than 2 Kcal, making this species an alternative source of healthy food to reduce obesity. Regression analysis indicated that Cu, Cd, and Pb had significant effect on 2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, calories, vitamins, and pigment content of the collected oysters. [ABSTRACT FROM AUTHOR]

The condition of fish relates to their energy reserves, and a suite of proxies exist to approximate condition, including biochemical and morphometric indices. Biochemical indices directly measure energy stores but are expensive and sometimes lethal. Morphometrics offer several advantages, but their utility as condition proxies is debated and largely untested experimentally. Here, we manipulated the condition of yellowfin bream (Acanthopagrus australis, Günther, 1859) via food reduction to simulate the effect of poor habitat quality and calculated a variety of condition indices through time. We measured four non‐lethal morphometrics (Fulton's K, Le Cren's relative condition, width‐to‐length ratio and girth), the hepatosomatic index and a biochemical benchmark (liver lipid content). Girth and width‐to‐length ratio were reasonably well correlated with lipid content (R2 = 0.74 and 0.56, respectively). The hepatosomatic index was only weakly or uncorrelated to other indices, including lipid content (R2 = 0.35). Where precise estimates of body condition are not needed or repeat measures on the same individual are useful, non‐lethal morphometrics provide a fast, cheap and non‐lethal alternative to biochemical and lethal morphometric methods for this species. We finish by outlining how artificial intelligence‐based automation can be combined with morphometrics to further enhance ethical monitoring by eliminating the need to capture and handle fish entirely. [ABSTRACT FROM AUTHOR]

The alveolate protist Perkinsus olseni infections impose considerable stresses on the host Manila clam Ruditapes philippinarum, often reducing their tissue weight due to the drain on energy resources. However, the relationship between condition factors and P. olseni infection exhibits inconsistency in different scenarios, as it is influenced by various factors such as environmental conditions, food availability, and reproductive conditions. To gain deeper insights, we surveyed Manila clams occurring on tidal flats in Anmyeondo Island, Cheonsu Bay to assess P. olseni intensity and its effects on the fitness of Manila clams. The Ray's fluid thioglycollate medium assay revealed that P. olseni infection in clams from inner Cheonsu Bay had considerably greater P. olseni intensities in May and September 2021 than those from outer Cheonsu Bay and reference sites (P < 0.05). Despite the high level of P. olseni infection, condition index (CI), a ratio of the flesh weight to the shell weight, in clams from inner Cheonsu Bay was also significantly higher than in clams from outer Cheonsu Bay and reference sites (P < 0.05). A noteworthy finding of this study was the positive association between P. olseni infection intensity and CI in clams, which suggests that despite the high parasite load, clams were able to maintain a higher CI, possibly due to the abundance of nutrients and organic matter present in the inner bay. The P. olseni infection intensities measured in September were significantly higher at most of the sampling sites in the inner and outer bay, which could be associated with the poor health condition of clams during a post-spawning period. These results highlight the complexity of bivalves' ecological relationships in Cheonsu Bay and offer new insights into their adaptability accompanied by other factors to parasite stressors. [ABSTRACT FROM AUTHOR]

The current study aimed to describe the annual gametogenic phenology of the oyster Magallana bilineata (Röding, 1798) (=Crassostrea madrasensis), which is found on the west coast of Moheshkhali Island, Cox's Bazar, Bangladesh. Samples were drawn monthly from the intertidal region during low tide, from which 20 adult individuals were selected at random for biometry and histology. The mean condition index (CI), a ratio of tissue wet weight (g) to shell length (cm), varied from 0.58 ± 0.08 to 1.32 ± 0.36. Histology revealed two spawning cycles in the habitat of M. bilineata over the 12 months of the study. Gametogenesis initiated in December and May, and ripe animals principally occurred from July to September and February to May. In the habitat, M. bilineata exhibited two spawning peak periods: April to June and August to October. The undifferentiated stage as a preparatory step for the next spawning extended from November to February for the first spawning cycle and for a brief period in June for the next spawning cycle. The initiation of spawning in March could be associated with the high-level decline of salinity and increased temperature between February and March, in association with the annual rainfall start, whereas the next spawning cycle could be associated with a gradual increase in salinity. No spawning activity was reported from December to February, when the water temperature remained below 22 °C. Further study could be undertaken on the timing of spatfall of M. bilineata in the habitat to harvest spats for commercial farming of this promising species.

Jembatan adalah suatu prasarana transportasi darat yang dapat dilalui oleh kendaraan atau pejalan kaki untuk melintasi medan yang sulit seperti sungai, danau, jalan raya, jalan kereta api, dan sebagainya. Mengingat pentingnya peranan jembatan bagi kehidupan manusia, maka harus ditinjau kelayakan konstruksi jembatan yang ada hubungannya dengan klasifikasi jembatan sesuai dengan tingkat pelayanan dan kemampuannya dalam menerima suatu beban. Dalam studi ini, Penulis melakukan penilaian menyeluruh terhadap kondisi Jembatan Mahulu, Kalimantan Timur, dilibat dari kerusakan yang terjadi pada setiap bagian jembatan. Hasil kajian ini diharapkan dapat memberikan pedoman praktis dan rekomendasi yang dapat diterapkan oleh pemangku kepentingan untuk meningkatkan kehandalan dan kinerja Jembatan Mahulu. Dari hasil penialian pada Jembatan Mahulu diketahui bahwa jembatan masuk kategori rusak berat dengan nilai 3 dan sisa umur jembatan diketahui hanya 41 tahun

Abstract Background Most aquatic biota's reproductive biology and life cycle are essential to the sustainable management and development of coastal ecosystems and aquaculture. The bivalve Paphia textile (Gmelin 1791), also known as Paratapes textilis, has an economic value in Indo-Pacific waters, including the Red Sea and the Suez Canal lakes, the Egyptian coasts. However, P. textile suffers from extensive fishing and exploitation. Aim The present work aims to study the Paphia textile's reproductive cycle on the Egyptian coasts of the Red Sea for the first time. It helps to manage and develop the coastal ecosystems and aquaculture. Methodology Samples were collected monthly from two saline lakes in the Suez Gulf from December 2019 to November 2020. As part of the comprehensive research study, sex ratio, condition index, sexuality, histological analysis of gonads, shell size, and gonad index were used to investigate the reproductive cycle. Results The results reveal a male-biased sex ratio, possibly due to anthropogenic stressors. The Paphia textile is dioecious. No hermaphrodite cases were observed in the studied specimens. The condition index in winter and spring indicates periods dominated by mature individuals. Five reproductive maturity stages were assigned for both P. textile males and females. Due to the simultaneous development of several developmental stages monthly throughout the sampling year, warm water may be responsible for non-sequential gametogenic cycles. As measured environmental parameters correlate with maturity stages, temperature, salinity, and chlorophyll a play important role in gonad growth. The size at first sexual maturity at which 50% of the Paphia textile population reached maturity ranged from 28.60 to 31.50 mm for females, and between 31.70 and 34.10 mm for males. As the gonad index increases during the ripe stages, this index decreases during the resting, spawning, and spent phases. Conclusions The findings suggest the most suitable temperature for aquaculture spawning is between 20 °C and 30 °C in subtropical waters. Fishing should generally be prohibited at sizes less than 28.60 mm for better management and sustainability of this valuable aquatic resource on the Egyptian coasts of the Red Sea.

The average values of the seasonal flesh biochemical composition (%) of the pearl oyster Pinctada imbricata radiata originated form 2 sampling sites, the gulfs of Evoikos (E) and Saronikos (S) in the Western Aegean Sea, showed that is rich in proteins (64.00 ± 1.86 -(E), 64.67 ± 2.95-(S)) with low fat content (10.96 ± 1.04-(E), 11.86 ± 1.13-(S)) and carbohydrates (13.29 ± 2.48- (E), 9.94 ± 4.32 (S)). The condition index ranged from 26.16% ± 5.04 in the autumn in (E), to 44.73% ± 7.50 in the summer in (S). The meat yield varied from 20.49% ± 3.20% in the summer in (E) to 30.73% ± 3.47% in the summer in (S). Both results demonstrate the high nutritional profile of the pearl oyster, supporting its suitability as a potential new Mediterranean seafood source for human consumption.

South Korea is implementing various policies to address the aging of infrastructures and improve road infrastructure management. Moreover, numerous research projects aiming at the development of necessary technologies for the proper implementation of these policies are underway. This study specifically aims to overcome existing problems in bridge pavement maintenance, such as the inaccuracy of future condition predictions and the selection of incorrect evaluation indicators. Our goal is to provide a new approach for the improved management of the bridge pavement management system (BPMS). To address the issues of accuracy in future condition prediction and evaluation indicator selection within the existing maintenance system, we utilized particle filtering, a Kalman filter method among machine learning techniques. This method allows for the prediction of future conditions, based on the nonlinearly collected bridge pavement conditions within BPMS. Furthermore, we proposed a systematic bridge pavement management strategy. This strategy utilizes traffic volume (ESALs; equivalent single axle loadings), a factor that can influence the future condition of bridge pavement, in correlation with the future condition predicted through particle filtering within BPMS. [ABSTRACT FROM AUTHOR]

Meretrix meretrix is one of the economical shellfish that has been exploited in Kendari Bay, Indonesia. Several studies have been done, but its growth pattern and condition index are not fully known. This study aims to determine its growth pattern and condition index at the Kambu River estuary, Kendari Bay. This research was conducted for 6 months from August 2021 to January 2022. Clams were collected using a rake, cleaned, and brought to the laboratory to be measured for length and weight using calipers and scales with an accuracy of 0.1 mm and 0.01g, respectively. Furthermore, the clam meat was dried using an oven and weighed. Data on growth and condition index were analyzed using simple regression and the Mann-Whitney test, respectively. The results showed that the growth of M. meretrix was in negative allometric conditions, with b values in males and females in the range of 2.20-3.00 and 1.86-2.73, respectively. The condition index of male and female clam ranged from 1.86-2.62 and 1.66-2.41, respectively, and differed significantly by month. The results of the Mann-Whitney test on clam showed that there was no significant difference between August-November and December-January. In conclusion, male and female clam had relatively different patterns based on the observation period, while the condition index was in the skinny and medium category. [ABSTRACT FROM AUTHOR]

Subjected to complex loadings from the wheel–rail interaction, turnout rail is prone to crack damage. This paper aims to develop a condition evaluation method for crack-alike damage detection of in-service turnout rail. A covariance-based structural condition index (CI) is firstly constructed by fusing the time-frequency components of responses, generating a series of patterns governed by the interrelationships between column members in the CI matrix. The damage-sensitive interrelationships latent in CI are then modeled using Bayesian regression and historical data, and baseline patterns are built with predictions of the models and new inputs. The deviations between the baseline patterns and the actual patterns of the newly observed CI members are quantitatively assessed. To synthetically consider the individual assessment results, a technique is developed to combine the individual assessment results into one synthetic result by designing a group of suitable weights taking into consideration both probabilistic confidence and reference model error. If the deviations are within a tolerable range, no damage is flagged; otherwise, damage existence and severity are reported. A case study is conducted, in which monitoring data from the database of a railway turnout are applied to build the CI matrix and examine the damage identification performance of this method. Good agreement between actual conditions and assessment results is found in different testing scenarios in the case study, demonstrating the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Simple Summary: The increased application of chromium compounds in several fields has resulted in elevated levels of toxic hexavalent chromium (Cr6+) in the aquatic environment, thus creating the potential for bioaccumulation of Cr6+ in the tissues as well as eliciting various toxic effects in organisms. The present study investigated the effects of Cr6+ exposure on the tissue distribution, proximate composition, and histopathology of an aquatic mollusk, periwinkle (Littorina littorea). The animals were exposed to sublethal concentrations of Cr6+ (0.42, 0.84, and 4.2 mg/L) for 30 days. Exposure to Cr6+ resulted in changes in the proximate composition and histological architecture of L. littorea. There was a low potential for bioaccumulation of Cr6+ in the tissue of L. littorea. Thus, its consumption did not pose any serious health risks to humans. The increased use of hexavalent chromium (Cr6+) in various industrial applications has contributed to its elevated levels in the environment, especially the aquatic environment. Thus, there is the potential for accumulation of Cr6+ in the tissues of aquatic organisms and consequent toxic effects. The toxic effects of Cr6+ in aquatic organisms have been widely reported; however, little is known about the patterns of tissue accumulation of Cr6+ and its toxicity in aquatic mollusks. Thus, the present study investigated the effects of Cr6+ exposure on the tissue distribution, proximate composition, and histopathology of an aquatic mollusk, periwinkle (Littorina littorea). The animals were exposed to sublethal concentrations of Cr6+ (0.42, 0.84, and 4.2 mg/L) for 30 days, after which the condition index, tissue accumulation, proximate composition, and histopathological effects were determined. The control animals were maintained in a medium that did not contain Cr6+ (0 mg/L). The condition index did not differ significantly among the groups. The levels of Cr6+ in the tissues differed significantly among the different tissue types while there was no significant effect of the exposure concentration, except in the foot tissue. The proximate parameters (protein, carbohydrates, lipid, crude fiber, and moisture contents) differed significantly among the groups. The protein contents of the exposed animals were significantly lower than those of the control animals and the histological architecture of the major organs was altered in the chromium-exposed animals. The findings from this study indicate a low potential of L. littorea to bioaccumulate Cr6+ in its tissues at the low exposure concentrations tested in this study; as such, its consumption may not pose any serious health risks to humans. However, changes in the proximate composition and histological architecture of the exposed L. littorea show that Cr6+ is potentially toxic to periwinkles. [ABSTRACT FROM AUTHOR]

Road structures undergo a series of chemical and physical processes once they are put into service. This phenomenon results from the action of the load and the influence of the environment, which causes their progressive deterioration. In order to mitigate the risk of progressive deterioration and guarantee their stability and durability, various maintenance tasks are required, including visual inspections. The Intelligent Bridge Management System of Colombia (SIGP) includes visual inspection as one of its modules. The system has been designed based on state-of-the-art criteria and national experience with relevant damages and bridge collapses. This paper presents the visual inspection methodology, which includes several stages such as a classification scale, condition index, evaluation areas, damage catalog, and evaluation criteria. In addition, a digital application has been developed to facilitate real-time data collection during field inspections using mobile devices, which can be uploaded directly to the system database hosted in the cloud. The results from the inspection of bridges of different typologies and years of construction are presented, as well as general inspection results from 150 bridges in Colombia. The relevance, comprehensiveness, and accuracy of the inspection are supported by a damage catalog, which allows the identification of intervention needs and reduces the bias of the collected data.

The infrastructure of ASFiNAG is mainly built from reinforced and prestressed concrete, which despite all regular maintenance measures, is subject to ageing and degradation. The major degradation process is chloride attack, followed by carbonation, which both lead to corrosion of the reinforcing steel. A new method, which represents a significant improvement on previous assessments, is used in this paper to analyze chlorides in concrete. The paper also introduces a new concept for the durability assessment by using objective indicators, like chloride content, electrical resistivity, and corrosion potential. For objectivity and a reliable determination of the condition state, an overall performance index derived from the condition indices using an analytic hierarchy process (AHP) is adapted. The model is applied to excellent and dense data from a monitoring system and investigations taken from reinforced concrete components beside a motorway. [ABSTRACT FROM AUTHOR]

Background: Most aquatic biota's reproductive biology and life cycle are essential to the sustainable management and development of coastal ecosystems and aquaculture. The bivalve Paphia textile (Gmelin 1791), also known as Paratapes textilis, has an economic value in Indo-Pacific waters, including the Red Sea and the Suez Canal lakes, the Egyptian coasts. However, P. textile suffers from extensive fishing and exploitation. Aim: The present work aims to study the Paphia textile's reproductive cycle on the Egyptian coasts of the Red Sea for the first time. It helps to manage and develop the coastal ecosystems and aquaculture. Methodology: Samples were collected monthly from two saline lakes in the Suez Gulf from December 2019 to November 2020. As part of the comprehensive research study, sex ratio, condition index, sexuality, histological analysis of gonads, shell size, and gonad index were used to investigate the reproductive cycle. Results: The results reveal a male-biased sex ratio, possibly due to anthropogenic stressors. The Paphia textile is dioecious. No hermaphrodite cases were observed in the studied specimens. The condition index in winter and spring indicates periods dominated by mature individuals. Five reproductive maturity stages were assigned for both P. textile males and females. Due to the simultaneous development of several developmental stages monthly throughout the sampling year, warm water may be responsible for non-sequential gametogenic cycles. As measured environmental parameters correlate with maturity stages, temperature, salinity, and chlorophyll a play important role in gonad growth. The size at first sexual maturity at which 50% of the Paphia textile population reached maturity ranged from 28.60 to 31.50 mm for females, and between 31.70 and 34.10 mm for males. As the gonad index increases during the ripe stages, this index decreases during the resting, spawning, and spent phases. Conclusions: The findings suggest the most suitable temperature for aquaculture spawning is between 20 °C and 30 °C in subtropical waters. Fishing should generally be prohibited at sizes less than 28.60 mm for better management and sustainability of this valuable aquatic resource on the Egyptian coasts of the Red Sea. [ABSTRACT FROM AUTHOR]

The reproductive biology of Mactra stultorum from the Gulf of Gabes was investigated monthly during a one-year period (2017). This study is the first study examining its reproductive biology during one-year in the south of Tunisia. The overall samples presented a balanced sex ratio, with males dominating among smaller individuals (< 22 mm) and females predominating in larger size classes (> 34 mm). The obtained total sex ratio (F:M) was equal to 1.03:1. The size at first maturity (SL50%) was 20.43 and 22.10 mm for males and females, respectively. The seasonal variations assessed through macro- and microscopic characteristics in the gonads of both sexes indicated a clearly defined annual reproductive cycle with a principal spawning peak during summer and a resting period during December and January. The reproduction of M. stultorum was strongly influenced by fluctuations in the seawater temperature, as reflected through the temporal variation in the gonadal cycle, condition index (CI) and tissue weight rate (TiWR). If managed properly, M. stultorum is expected to meet the domestic market demand through artisanal fishery. The adoption and implementation of rules, such as limiting the size of clams, is required to protect this new exploitable fishery resource. [ABSTRACT FROM AUTHOR]

The reproductive performance knowledge of economically important bivalves is essential to establish better shellfishery management measures and aquaculture programs. The reproductive cycle, as well as the nutrient storage and utilization of two Portuguese Cerastoderma edule populations from Óbidos and Ria Formosa lagoons were characterized by evaluating gonadal development stages, gonadal and condition indexes, as well as glycogen and total lipid content, over several consecutive years. The relationship between reproduction and environmental parameters (sea surface temperature and chlorophyll a) was assessed. The reproductive cycle of both populations of C. edule followed a clear seasonal pattern. The onset of gametogenesis took place in early autumn for both populations, and its evolution coincided with a temperature decrease which progressed throughout the winter. The mature stage was reached in spring, followed by a spawning period during spring and summer, triggered by a rise in temperature. After spawning, both populations progressed to a prolonged inactive stage. The condition index reflected the accumulation and utilization of glycogen, which was considerably higher in the Óbidos population. However, no relationships were found in the reproductive cycle of the species. Total lipids remained similar not only during the gametogenesis period, but also during the spawning period, which may be related to successive and simultaneous gamete production and release. [ABSTRACT FROM AUTHOR]

The average values of the seasonal flesh biochemical composition (%) of the pearl oyster Pinctada imbricata radiata originated form 2 sampling sites, the gulfs of Evoikos (E) and Saronikos (S) in the Western Aegean Sea, showed that is rich in proteins (64.00 ± 1.86 -(E), 64.67 ± 2.95-(S)) with low fat content (10.96 ± 1.04-(E), 11.86 ± 1.13-(S)) and carbohydrates (13.29 ± 2.48- (E), 9.94 ± 4.32 (S)). The condition index ranged from 26.16% ± 5.04 in the autumn in (E), to 44.73% ± 7.50 in the summer in (S). The meat yield varied from 20.49% ± 3.20% in the summer in (E) to 30.73% ± 3.47% in the summer in (S). Both results demonstrate the high nutritional profile of the pearl oyster, supporting its suitability as a potential new Mediterranean seafood source for human consumption. [ABSTRACT FROM AUTHOR]

We measured survival, growth and body condition of eight hatchling cohorts of desert tortoises in captivity over 11 years to evaluate head-starting methods. At 11 years of age, seven times as many of the first cohort had survived than if they were free-living tortoises. Improvements in predator control, food and water supplementation and pen structure increased survival from seven to 10 times that under wild conditions. Annual survival averaged 96%. Carapace length (CL) increased 6.95 mm per year, similar to that of free-living tortoises. Annual growth rates varied with calendar year (possibly reflecting food and water supply), age, cohort (year hatched), mother, and in four dry years, with crowding. Most of the first cohort grew to a releasable size (CL >100 mm) by their ninth year. Body Condition Indices (CI) remained high, indicating little dehydration despite droughts in eight of the 11 years, because irrigation offered drinking opportunities. Head-started tortoises developed fully-hardened shells (>98% of adult shell hardness) earlier (10.1 vs 11.6 years), but at a larger CL (117 vs 104 mm), than did free-living tortoises. Selective feeding in head-start pens decreased subsequent germination of favored wildflower species, apparently by reducing the natural seedbank. Consequently we reseeded and irrigated each autumn to promote subsequent spring food supply. We irrigated in early summer to enable drinking and ensuing consumption of dry, dead plants and Bermuda grass hay, a supplement. These procedures can greatly improve juvenile survivorship, and increase numbers of hard-shelled, midsized juveniles to help augment wild populations.

Native to the Gulf of Mexico, Gulf wedge clam (Rangia cuneata) has been successfully invading Baltic Sea since first introduction with ballast waters in 2010. In this study, we report new occurrence sites in the Pomeranian Bay and in the brackish water of the Szczecin Lagoon. We aimed to describe the structure and stability of the new population of Gulf wedge clam using ecological indicators (i.e. condition index, length-at-age) and a molecular approach targeting first cytochrome oxidase subunit (COX1) fragments. The study showed an age structure dominated by adult clams (aged 4+), rather than the often reported juveniles. We found that the condition of the R. cuneata population in the Pomeranian Bay is characteristic of the expansion model after bottleneck. Genetic analyses indicated low nucleotide (π = 0.00387 ± 0.00012) and haplotype (h = 0.79 ± 0.018) diversity. A haplotype network inferred by a median-joining method showed lack of haplotype H6 (Chesapeake Bay, NW Atlantic) and numerous individuals with haplotype H1 (Gulf of Mexico). Demographic parameters (non-significant Tajima’s D = 2.058, Fu’s Fs = 2.298, Fu and Li’s D* = 1.195, and significant Fu and Li’s F test = 1.757) suggested that the population underwent a moderate population bottleneck, while analysis of mismatch distribution showed a bimodal shape which may imply population admixture as a consequence of “allelic surfing”. Moreover, we concluded that R. cuneata has successfully invaded the basin of the LNG terminal, although our study proved non-linear growth of this species.

Pacific Northwest Indigenous communities historically managed terrestrial and marine environments to increase the productivity and access of traditional foods. Sea gardens, also called clam gardens, were an Indigenous aquaculture method that increased traditional food habitat for targeted food species such as bivalves. This study utilized fatty acid biomarker analysis alongside stable isotopic analysis with bivalve condition indices of traditionally harvested littleneck clams (Leukoma staminea) to investigate dietary and trophic differences between sea gardens and non-walled beaches in Kanish Bay, Quadra Island, British Columbia. We utilized non-metric multidimensional scaling, distance-based redundancy analysis (db-RDA), and Bayesian three-source isotopic mixing models to examine impacts of environmental drivers on bivalve dietary composition and condition at four sea garden sites and four non-walled sites. Bivalve tissue saturated fatty acids (sum SFAs) showed statistical significance (Mann-Whitney U-Test, W = 3447, P = 0.01), indicating that sea garden clams (x2 = 34.96; SD = 7.56) had higher mean relative percent areas of SFAs compared to nonwalled sites (x2 = 31.76; 7.71). Bivalve monounsaturated fatty acids (MUFAs) showed statistical significance (Mann-Whitney U-Test, W = 1202, P = 0.01, a = 0.05), indicating sea garden clams (x2 = 3.48; SD = 3.78) had lower mean relative percent areas of MUFAs compared to those in non-walled sites (x2 = 6.97; SD = 5.90). Sea garden bivalves were found to feed at a higher trophic level, with a slimmer dietary range, compared to non-walled clams. Both dietary marker differences and differentiated trophic positioning suggest decreased physiological stressors impacting feeding of bivalves, differences in dietary particulate intake, or a combination of both occurring at sea garden sites compared to non-walled sites. Correlations within a db-RDA indicate that bivalves with high body condition indices at sea garden sites were benefiting from decreased stress related to favorable salinity and oxygen parameters, which positively impacted bivalve feeding and respiration. Observed trophic niche differences and fatty acid differences would also be explained by this suggested mechanism. We conclude that partial trophic shifts and fatty acid changes of sea garden L. staminea bivalves are consistent with stress-alleviated bivalve responses, and match correlated variables in our db-RDA. Trophic niche differences and fatty acid shifts between sea gardens and non-walled sites should be further explored by using a quantitative method to identify sea gardens from nonwalled sites in addition to established field verification methods. [ABSTRACT FROM AUTHOR]

The length-weight relationship and condition index of pokea clams in the Laeya River are not fully known. This study was aimed to determine the length-weight relationship and condition index of pokea clams in the Laeya River, Southeast Sulawesi. This research was conducted 10 months from May 2016 to February 2017 in the Laeya River, Southeast Sulawesi. Pokea clams are collected using a shovel. The length and weight of each clam was using calipers and analytical scales with accuracy of 0.05 mm and 0.01 g, respectively. The weight of the shell and dried meat was obtained by drying the shells first using an oven and weighing using an analytical balance with an accuracy of 0.01 g and 0.0001 g, respectively. The results showed that the relationship between length and weight of pokea clams in males and females were 2.61 and 2.78, respectively; with R2 values of 0.89 and 0.93, respectively. The highest b values for males and females were found in July with values of 3.03 and 2.94, respectively. The lowest b value was found in November with values of 2.45 and 2.46, respectively. The condition index values for males and females were 4.7 ± 2.2 and 5.17 ± 2.32, respectively. The highest condition index was found in May with values of 6.00 ± 3.07 and 7.83 ± 2.55, respectively. The condition index values for males and females increased with increasing shell size. Male and female at the largest size (6.01-6.05 cm) had the highest index with values of 8.05 ± 6.41 and 9.12 ± 3.38, respectively. In conclusions, the growth was negative allometric pattern, condition index was in fat category, and had peak spawning in July and experienced partial spawning in September-February. [ABSTRACT FROM AUTHOR]

South African agriculture accounts for 62% of the national water demand. Almost 45% of the water is wasted. Therefore, irrigation systems need to improve their water-use efficiency (WUE). However, the WUE of smallholder irrigation schemes in the country, including Agri-Parks, is not precisely known. A study was performed at four Agri-Parks (Rooiwal, Soshanguve, Tarlton, and Westonaria) in Gauteng province to assess the condition and performance of the irrigation systems, as part of a project that aimed to develop a WUE model for smallholder irrigation systems. The Agri-Parks were equipped with efficient irrigation systems in forms of drip and microjets. The assessments were performed at the system component level in February–March 2021. A Condition Assessment Model (CAM), developed by ARC-NRE/AE, was used for the condition assessment. Enumerators observed the system components visually and assigned conditions, which they uploaded into the model to generate condition indices (CIs). Water conveyance efficiency (CE) and distribution uniformity (DU) were assessed on delivery and infield systems, respectively. The CI values ranged 4–6, implying significant deterioration had occurred. The CE was 61–78%, while the DU was 60–95%. The infield system CI correlated positively with the DU, suggesting the CI could predict the DU in drip systems, which was encouraging for the proposed WUE model. However, further research covering a longer period and more Agri-Parks is recommended. [ABSTRACT FROM AUTHOR]

The relevance of the study is related to the need to determine the current state of windbreaks as a component of the forest-agrarian landscape of a particular region. The purpose of the study is to conduct a comprehensive assessment of windbreaks. During the study, data from remote sensing of the Earth using satellite imagery was utilised, which allowed for determining field parameters, the placement of the windbreak system, and their characteristics. Forest inventory works were conducted using commonly accepted methods in forest mensuration, with adjustments made specifically for windbreaks. The quality class of windbreaks was determined based on the percentage of healthy trees out of the total number, and the sanitary condition index was calculated according to established categories. The analysis of the obtained data clearly shows a decline in the quality sequence of common oak from 9 to 3 units within the plantations. The windbreaks were created using the method of oak nest planting, with oak nests placed at a spacing of 5.0*3.0 m and a total windbreak width of 15.0 m. Two additional rows of companion trees were introduced in the wide 5-metre alleys, and companion and shrub species were added within the nest rows. The analysis of the characteristics of windbreaks showed that they have protective heights ranging from 19.6 m to 23.4 m and provide reliable protection for adjacent agricultural fields. Based on the range of effective protective effects of windbreaks, it can be noted that the calculated indicators provide protection with a reliable safety margin of up to 17%. If there is a need to create new windbreaks using the nest planting method in the future, a more efficient scheme is proposed, which involves placing companion tree species in the outer rows to prevent the crowns of the inner rows from spreading towards the field. As a result of the obtained findings, it became possible to conduct a comprehensive expert assessment of the state of windbreaks according to the following criteria: forestry and inventory parameters, meliorative properties, and the sanitary condition index [ABSTRACT FROM AUTHOR]

Oysters are a foundational part of their ecosystem and research has shown they are negatively impacted by exposure to microplastics (MPs). High MP levels have been documented in waters surrounding oyster reefs, and as filter feeders, oysters can ingest MPs along with their food. Here, we determined MPs (>30 µm) in oysters (Crassostrea virginica) from ten sites across the Mississippi Gulf Coast. Further, a subset of these samples was dissected to quantify MPs within specific tissues. Average concentrations ranged from 30.7± 11.5 to 4.7 ± 0.25 putative MPs/g wet weight (ww) of whole tissue, with sites inside bays near population centers displaying higher levels of MPs than those exposed directly to the Gulf. Mantle, gill, and adductor muscle tissues had similar concentrations of putative MPs (15.9 ± 13.4, 11.5 ± 8.6 and 12.8 ± 6.7 MPs/g, respectively), whereas digestive system tissues had lower concentrations (6.8 ± 6.1 MPs/g of tissue). This suggests that most MPs in an oyster likely adhere to external tissues and are not actually ingested. Most of the MPs retained were in the smallest size fraction of 30‐90 µm (80%), followed by 125‐250 µm (9%), 90‐125 µm (8%), and >250 µm (3%). Analysis of samples from Biloxi Bay by µ‐FTIR to assess MP composition shows that polyurethane, polyethylene, and polyamide are common, but additional analyses are needed to fully characterize the MP profile across sites. Overall, this work provides much‐needed empirical data on the abundances and sizes of MPs in oysters from the Mississippi Sound, as well as the tissues where they reside. [ABSTRACT FROM AUTHOR]

In this paper, a new D-distance factor is proposed to determine the failure probability and to prioritize maintenance actions of power circuit breakers in high-voltage substations. The D-distance factor is calculated by using the condition index and renovation index of a high-voltage circuit breaker (HVCB). To facilitate effective decision-making on maintenance with a simple method and less computational effort, the proposed model incorporates the weighting–scoring method (WSM) and analytical hierarchy process (AHP) with the various diagnostic methods for condition index assessments as well as the operation requirements of HVCBs for renovation index assessments. Many significant parameters from circuit breaker testing, such as insulation resistance, contact resistance, contact timing, SF6 gas measurements, gas leakage rate, visual inspection, etc., have been considered for condition index determination. In addition to these, other significant parameters, such as age of the circuit breaker, age of the interrupter and mechanism, number of fault current interruptions, actual load current to rated current ratio, actual short circuit current to rated interrupting current ratio, maintenance ability, spare parts availability, maintenance expertise level, etc., are also considered for renovation index determination. To validate the proposed model, the practical test data of twenty 115 kV HVCBs in various substations of a distribution utility in Thailand were utilized and tested. By analyzing the actual condition and operation requirement of the circuit breaker, the output, as the condition index and renovation index using the proposed method, is discussed with HVCB experts in the utility to adjust the scores and weights of all criteria to obtain the most accurate and reliable model. The results show that the D-distance technique measured from the risk matrix, which is defined as the failure probability, can be used to rank the maintenance schedule from urgent to normal maintenance tasks. In addition, various failure probabilities in the risk matrix of the circuit breaker can be used to determine the appropriate maintenance strategies for the power circuit breaker in each group. Finally, the proposed method could help the utility managers and maintenance engineers manage the maintenance planning effectively and easily for thousands of HVCBs in the grid, and it can be further applied with other high-voltage equipment in both transmission and distribution systems to facilitate the maintenance activities according to available costs and human resources. [ABSTRACT FROM AUTHOR]

In this study, we investigate whether the Tukey M robust regression method provides a solution for the data sets suffering from multicollinearity problem. It is observed that high values of variance inflation factors (VIF) which is a sign of the multiple linear link among the explanatory variables, cannot be controlled by the robust methods which work through the residual values. The reason for this fact is that multicollinearity and high values of VIF which is a result of multicollinearity do not produce extreme residuals. For this reason, the robust methods cannot provide a solution for the high VIF problem. This fact is shown by an extensive simulation study. In the simulation study, the explanatory variables were derived from trivariate normal distribution for three different correlation values. In this study, we also used two real-life data examples and we observed that the results support the findings of the simulation study. For all these reasons, we can conclude that specialized methods should be utilized in the case of multicollinearity. [ABSTRACT FROM AUTHOR]