Search

Our study is a pioneering exploration of the microbiome in the soil of the Sumaco stratovolcano and an assessment of the effects of an elevational gradient and related physicochemical soil parameters on richness and community structure. The Sumaco, as an isolated Amazonian stratovolcano, may be among one of the least studied ecosystems in Ecuador and perhaps the Amazon region. Universal patterns remain unresolved or available information inconclusive to establish a supported consensus on general governing processes by which elevation and its associated environmental gradients may determine the microbial richness and community structure. We tested a recent proposal on how microbial diversity responds to montane gradients, placing a central role in soils as potentially independent of altitude along an elevational gradient. Correlations and effects among soil physicochemical parameters and altitude were contrasted against richness and community structure through quantitative ecology. The most informative physicochemical parameter in our assessment of bacterial community structure was neither pH nor altitude, but sulfur, which was mostly independent of the other tested parameters. We established a positive effect of richness by parameters associated with metallic cations such as Mn2+, and CEC, which were negatively correlated to altitude and pH. The possible relation between the significant role of sulfur on bacterial community structure with the unique geological origin of the Sumaco stratovolcano should be examined in the context of specialized sulfur metabolisms and additional information on community structure and environmental constraints. Our study establishes an initial baseline for further explorations of microbial diversity in this unexplored tropical stratovolcano.

Forest biomass is an important component of terrestrial carbon pools. However, how climate, biodiversity, and structural attributes co-determine spatiotemporal variation in forest biomass remains not well known. We aimed to shed light on these drivers of forest biomass by measuring diversity and structural attributes of tree species in 400-m2 plots located every 100 m along a 4200-m elevational gradient in the eastern Himalayas. We applied structural equation models to test how climate, species richness, structural attributes, and their interactions influence forest biomass. Importantly, species richness was a stronger driver of biomass than environmental and structural attributes such as annual air temperature or stem density. Integrating the availability of energy and the demand for water, potential evapotranspiration was more strongly correlated with biomass than water availability, likely due to the strong influence of the Indian summer monsoon. Thus, interactions between climate and tree community composition ultimately control how much carbon is stored in woody biomass across bioclimatic gradients. This fundamental understanding will support predictive efforts of the forest carbon sink in this hydroclimatically important region and help preserving regional forests as a potent natural solution for climate change mitigation.

This dataset consists of Bearded Vulture Gypaetus barbatus occurrence points which were used to develop a distribution model to study its suitable habitat of this species. Using these data, we modelled the current distribution of Bearded Vulture throughout its entire range and projected the Last Glacial Maxima (LGM), Mid-Holocene (MH) and future distribution under 2070s climate change scenarios. We compiled these data from the entire distribution range in Asia, Europe and Africa using different sources: freely accessible online resources including, eBird and GBIF repositories, published reports and grey literature and occurrence data collected by the authors in the field, mostly in Nepal.

Peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae) is native to South and South-East Asia. It is a polyphagous species and has a high reproductive potential (approx. 600 eggs in a lifetime), high biotic potential, i.e., several generations of progeny per year. The species has the rapid dispersal ability and can be active throughout the year. Its establishment may have a serious impact on the environment following the initiation of chemical and/or biological control programmes. B. zonata is of quarantine significance to EPPO (European and Mediterranean Plant Protection Organization) countries and it is classified on the A1 list of pests recommended for regulation as quarantine pests by Centre for Agriculture and Biosciences International (CABI). The present study initiates an attempt to identify the larval (3rd instar) salivary gland polytene chromosome arms of B. zonata using Olympus phase contrast microscope CX 41. A photographic representation of the polytene chromosomes of this species associates with identifying tips as well as well defined characteristics of each polytene chromosome arms are described. Five long chromosomes with their identifying tips are recognized in each polytene nucleus. Polytene chromosomes are of special interest to construct a Genetic Sexing Strain (GSS) of a pest species and it can play an important role for the successful application of Sterile Insect Technique (SIT) in field application as part of the biological control programme under Integrated Pest Management (IPM) scheme.

The study aimed to test the potential anthelmintic activity of Salix babylonica (SB) extract for the control of gastrointestinal and pulmonary parasites in sheep and goats under field conditions. A representative sample of 20 % of all animals reared in 8 sheep and 7 goat farms was used in the study. Animals from each farm were randomly selected for a total number of 93 sheep and 75 goats. Animals suffered a natural gastrointestinal nematode infection and had never been treated with chemical anthelmintic drugs. The SB extract (20 mL) was orally administered weekly before the morning feeding to each animal for 60 days. Fecal eggs or oocysts were counted at 0, 1, 20, 40, and 60 days after starting the extract administration. Differences (P < 0.01) in the fecal oocyst and egg output of Eimeria, Dictyocaulus, and Moniezia were observed between sheep and goats. In addition, the treatment influenced (P < 0.05) egg outputs of Cooperia, Dictyocaulus, and Trichuris. Fecal egg or oocyst counts of Haemonchus contortus, Eimeria, Cooperia, Chabertia, Dictyocaulus, Moniezia, and Ostertagia were time-dependent (P < 0.05). For sheep, administration of SB decreased (P < 0.05) the fecal eggs count of H. contortus, Cooperia, Chabertia, Dictyocaulus, Moniezia, and Trichuris. After 20 days of treatment, H. contortus, Cooperia, or Moniezia were not detected. For goats, SB reduced (P < 0.05) the fecal egg counts of H. contortus, Cooperia, Chabertia, and Moniezia. Moreover, decreases were observed (P < 0.05) for Chabertia, Trichostrongylus, and Ostertagia. Eggs of H. contortus and Moniezia were not present in the feces after 1 day of administration of the extract. It could be concluded that the weekly administration of SB extract at 20 mL per animal can be used to treat gastrointestinal and lung nematodes of small ruminants in organic and traditional farming systems of tropical regions.

In a randomized block design experiment, the effect of fecal inocula from horses supplemented with live yeast (Saccharomyces cerevisiae) in diets containing 50% oat straw on in vitro total gas (gas production [GP]), methane (CH4), and carbon dioxide (CO2) productions as indicators of hindgut activity was assessed. Three commercial products of S. cerevisiae were tested (1) Biocell F53 (YST53), (2) Procreatin 7 (YST07), and (3) Biosaf SC47 (YST047). For the incubations, each product was added at 0 (control without yeast addition), 2, or 4 mg/g dry matter (DM). Fecal inocula for incubations with each treatment was obtained from Quarter Horse mares fed the same yeast additives for 15 days, resulting in four different fecal inocula (FI53, FI07, FI47, and FI00). The fecal content mixed with the culture media were used to inoculate three identical runs of incubation in bottles containing 1-g DM of substrate (a mixture of concentrate and oat straw [1: 1 DM]). The GP, CH4, and CO2 productions were measured at 2, 4, 6, 8, 10, 12, 24, and 48 hours post-incubation. Addition of additives YST53 and YST07 at 2 mg/g DM resulted in higher asymptotic GP (linear effect, P = .021) and GP during the first 12 hours of incubation (linear effect, P < .05) compared with control without yeast addition, with the highest value being for the dose 2 mg/g DM with the fecal inoculum FI53. The additive YST47 at all doses with fecal inoculum FI47 had lower GP (linear effect, P < .05) at different incubation hours compared with control. The additive YST53 increased GP, CH4, and fermentation kinetics at the dose 2 mg/g DM with decreasing CH4 production by 78% at 4 mg/g DM at 24 hours of incubation. Addition of YST53 at 2 and 4 mg/g DM with fecal inoculum FI53 enhanced fermentation kinetics (P < .05) compared with control and other additives at different doses. It can be concluded that the yeast additive Biocell F53 was the most effective at doses of 2 and 4 mg/g DM compared with other Saccharomyces st

We study networks of delay-coupled oscillators with the aim to extend time-delayed feedback control to networks. We show that unstable periodic orbits of a network can be stabilized by a noninvasive, delayed coupling. We state criteria for stabilizing the orbits by delay-coupling in networks and apply these to the case where the local dynamics is close to a subcritical Hopf bifurcation, which is representative of systems with torsion-free unstable periodic orbits. Using the multiple scale method and the master stability function approach, the network system is reduced to the normal form, and the characteristic equations for Floquet exponents are derived in an analytical form, which reveals the coupling parameters for successful stabilization. Finally, we illustrate the results by numerical simulations of the Lorenz system close to a subcritical Hopf bifurcation. The unstable periodic orbits in this system have no torsion, and hence cannot be stabilized by the conventional time delayed-feedback technique.

Cytotoxic, antioxidative burst and antileishmanial properties of leaf extract and fractions of Setaria megaphylla were investigated to ascertain the folkloric claims of its potency in inflammatory diseases and infections. The leaf extract and fractions of Setaria megaphylla were investigated for anticancer activity against HeLa cells using SRB method and DNA interaction activity using gel electrophoresis. Antioxidative burst activity of the extract in whole blood, neutrophils and macrophages was also investigated using luminol/lucigenin-based chemiluminescence assay. The extract and fractions were similarly screened for antileishmanial activity against promastigotes of Leishmania major in vitro. The GCMS analysis of the most active fraction against HeLa cells was carried out. The leaf extract was found to exert significant anticancer activity with the hexane fraction exhibiting the most pronounced effect. The crude extract and the fractions did not interact with DNA when investigated using electrophoresis. The extract prominently inhibited oxidative burst activity in whole blood, isolated polymorphonuclear cells (PMNs) and mononuclear cells (MNCs) when two different phagocytosis activators (serum opsonizing zymosan-A and PMA) were used. The extract also exhibited moderate antileishmanial activity against promastigotes of Leishmania major in vitro. GCMS analysis of active fraction revealed pharmacologically active compounds. These results suggest that the leaf extract/fractions of S. megaphylla possesses cytotoxic, antioxidative burst and antileishmanial activities and these justify its use in ethnomedicine to treat inflammatory diseases and microbial infections and can be exploited in primary healthcare.

Cytotoxic, antioxidative burst and antileishmanial properties of leaf extract and fractions of Setaria megaphylla were investigated to ascertain the folkloric claims of its potency in inflammatory diseases and infections. The leaf extract and fractions of Setaria megaphylla were investigated for anticancer activity against HeLa cells using SRB method and DNA interaction activity using gel electrophoresis. Antioxidative burst activity of the extract in whole blood, neutrophils and macrophages was also investigated using luminol/lucigenin-based chemiluminescence assay. The extract and fractions were similarly screened for antileishmanial activity against promastigotes of Leishmania major in vitro. The GCMS analysis of the most active fraction against HeLa cells was carried out. The leaf extract was found to exert significant anticancer activity with the hexane fraction exhibiting the most pronounced effect. The crude extract and the fractions did not interact with DNA when investigated using electrophoresis. The extract prominently inhibited oxidative burst activity in whole blood, isolated polymorphonuclear cells (PMNs) and mononuclear cells (MNCs) when two different phagocytosis activators (serum opsonizing zymosan-A and PMA) were used. The extract also exhibited moderate antileishmanial activity against promastigotes of Leishmania major in vitro. GCMS analysis of active fraction revealed pharmacologically active compounds. These results suggest that the leaf extract/fractions of S. megaphylla possesses cytotoxic, antioxidative burst and antileishmanial activities and these justify its use in ethnomedicine to treat inflammatory diseases and microbial infections and can be exploited in primary healthcare.

Some gemini surfactants in the series of 1,2-ethane bis(dimethyl alkyl (CnH2n+1) ammonium bromide) referred as n-2-n have been synthesized, where n = 10, 12 and 14. The purity of surfactants synthesized was checked by rutinary methodologies (1H-NMR, MS and elemental analysis). Their surface active properties at equilibrium in water at 25 °C were determined. The inhibitive effect of these compounds, in the case of iron immersed in 1 M HCl, was investigated through mass-loss, potentiokinetic methods and electrochemical impedance spectroscopy. Polarization data indicate that these compounds act as very good cathodic inhibitors of iron in 1 M HCl. In the anodic range, the surfactants studied do not show an inhibition effect at iron electrode potential more positive than -100 mV/Saturated Calomel Electrode. Impedance plots of iron in the presence of various concentrations of surfactants studied are similar to semicircles in the capacitive quadrant. The associated values of transfer resistances increase by increasing the additive concentrations. From all measurements performed, the variation of the inhibition efficiency versus concentration shows the same trend. The gemini surfactants appear to be adsorbed in the metal/liquid interface through the general adsorption mode following the Frumkin adsorption isotherm model. The electrochemical impedance spectroscopy shows that the maximum inhibition efficiency is attributed to a formation of an adsorbed layer at the iron surface. From tensiometric measurements, it was found that the ability of gemini surfactants studied to adsorb at the interface air/water is concordant with their order of the inhibition efficiency of iron corrosion.

Ligand-bound nuclear receptors (NRs) recruit cofactors such as members of the p160 family and CREB-binding protein (CBP) to activate transcription. We have cloned the Xenopus homologue of the human transcription intermediary factor 2 (TIF2), a member of the p160 family of cofactors. Xenopus TIF2 (XTIF2) mRNA is expressed homogeneously during late blastula–early gastrula stages and later becomes highly expressed in the notochord. To study the function of XTIF2 during development, we have used two dominant negative constructs, one encompassing the NR-binding domain and the other the CBP interacting region of XTIF2. Overexpression of the XTIF2 dominant negative mRNAs causes ectopic expression of Xenopus Brachyury (Xbra) and MyoD in all tissue layers. Moreover, ectopic expression of the dominant negative construct that contains the CBP-binding region produces strong phenotypes at hatching stage such as loss of head structures, shortened trunks and open blastopores, which can be rescued by XTIF2 coexpression. These observed defects are due, at least in part, to repression of dorsal mesoderm and endoderm genes. Our data suggest the existence of a NR pathway that requires XTIF2 and CBP to repress Xbra and XMyoD.

The forkhead type Brain-Factor 2 from mouse and chicken help pattern the forebrain, optic vesicle and kidney. We have isolated a Xenopus homolog (Xbf2) and found that during gastrulation it is expressed in the dorsolateral mesoderm, where it helps specify this territory by downregulating BMP-4 and its downstream genes. Indeed, Xbf2 overexpression caused partial axis duplication. Interference with BMP-4 signaling also occurs in isolated animal caps, since Xbf2 induces neural tissue. Within the neurula forebrain, Xbf2 and the related Xbf1 gene are expressed in the contiguous diencephalic and telencephalic territories, respectively, and each gene represses the other. Finally, Xbf2 seems to participate in the control of neural crest migration. Our data suggest that XBF2 interferes with BMP-4 signaling, both in mesoderm and ectoderm.