Significant Effect Of Temperature Research Articles

Effect of temperature on the embryonic and larvae development of discus fish Symphysodon aequifasciatus and time of first feeding.

This study aimed to analyze the influence of different temperatures on the embryonic and larval development of discus fish Symphysodon aequifasciatus and determine the time required for the beginning of exogenous feeding. Eggs and larvae were obtained from natural spawns and distributed in five treatments: 24.0, 26.0, 28.0, 30.0, and 32.0°C. To assess the developmental stages and embryonic structures, samples were taken at regular intervals and checked under an optical microscope. At the end of the experimental period, statistical analysis was performed, followed by Tukey's test. As a result, it was possible to observe the significant effects of temperature on the variables. It was noted that the temperature accelerated the embryonic and larval development of the discus and also contributed to a reduction in the time between the incubation period and the feeding transition. It was also noted that the incubation of eggs and larvae at a temperature of 24.0°C can cause damage to embryos, such as malformation of the body as well as anomalies in the circulatory system.

A Kinetic Study of Silver Extraction from End-of-Life Photovoltaic Panels through Gold-REC1 Process

Recycling materials from end-of-life devices and products is becoming increasingly a fundamental activity for the sustainable development of nations. With the return from the market of immense quantities of photovoltaic panels at the end of their life, it is essential to foresee processes for recovering and valorizing all the raw materials present in them to avoid wasting important flows of raw materials. This research introduces a novel process aimed at the recovery of silver and silicon from end-of-life photovoltaic panels. The leaching efficiency and kinetics of ground cake powder in sulfuric acid, ferric sulfate, and thiourea were investigated in the leaching system. In particular, the influences of significant parameters, including particle size, leaching temperature, and stirring rate, on the extraction kinetics were analyzed using the shrinking core model. The results showed silver dissolving mechanisms, in which more than 90% of silver recovery at 60 min of reaction time and 99% at 120 min was achieved (120 rpm, 53–125 µm, and 40 °C). The significant effect of the leaching temperature suggests that the process is under the control of the chemical reaction. Moreover, these results were confirmed by the regression analysis of the experimental data with the shrinking core model. It can be concluded that this newly proposed process, called Gold-REC1, allows the recovery of Ag and Si (solid residue from the process) with extremely high yields and rapid kinetics. The obtained results can provide fundamental data for developing end-of-life photovoltaic recycling on an industrial scale.

Optimizing growth and mitochondrial function in rainbow trout, Oncorhynchus mykiss through eco-friendly dietary and changes in water temperature regimen strategies

Developing sustainable aquaculture remains a challenge, notably finding suitable alternatives to marine ingredients in carnivorous fish diets such as rainbow trout (Oncorhynchus mykiss) in changing climate. These new diets are especially important because rainbow trout are an ecologically and economically significant aquaculture species. Therefore, we investigated the impact of sustainable ingredients and water temperature manipulations on rainbow trout growth characteristics and mitochondrial function. A total of 432 fish were fed four isocaloric, isolipidic, and isonitrogenous diets comprised 40 % crude protein and 20 % lipid and formulated as diet 1 (animal-based protein +25 % fish oil/ 50 % plant oil/ 25 % terrestrial animal oil), or diet 2 (animal-based protein +100 % plant oil), or diet 3 (plant-based protein +25 % fish oil/ 50 % plant oil/25 % terrestrial animal oil), or diet 4 (plant-based protein +100 % plant oil) at 14 °C or 18 °C or 20 °C water temperature. Results showed percent weigh gain (PWG) and specific growth rate (SGR), feed efficiency (FE), and feed intake (FI) were significantly (P < 0.05) higher in fish reared at 14 °C and 18 °C compared to 20 °C. The PWG, FE, FI, and SGR levels were significantly (P < 0.05) higher for fish fed diets 1 and 2 than those fed diets 3 and 4. Dietary composition influenced whole-body proximate composition, while temperature affected protein, moisture, and lipid contents. For protein, lipid, and energy contents, temperature-diet interactions were significant (P < 0.05). There were differences in mitochondrial enzymatic activities in muscle, liver and intestine. Diet affected only complex V activity in the liver, whereas temperature significantly (P < 0.05) affected the activities of complexes II, III, and V. A temperature-dietary interaction was observed for complex V. The temperature regimens, but not dietary composition, affected muscle mitochondrial enzymatic activities. There were significant (P < 0.05) effects of temperature on complex III, IV, and citrate synthase activities in the intestine, whereas dietary composition had no significant impact (P > 0.05). Based on diet, temperature, and diet-temperature interactions effects, selected genes were expressed differently in different tissues. The nd1, cox2, cytb, cox1, atp6 and PPAR-α genes were significantly influenced by diet and temperature interactions in muscle, liver and intestine. Overall, our results showed that both temperature and dietary composition had significant effects on growth characteristics, proximate composition, mitochondrial enzymatic activities, and their interactions on gene expression levels in rainbow trout. These findings underscore the importance of considering these factors in the development of plant-based aquafeeds in order to optimize growth and productivity.

Utilization of dragon fruit (Hylocereus undatus) peel-derived biochar for the adsorptive removal of tetracycline from aqueous solution

The peel of Hylocereus undatus was employed in the preparation of biochar and firstly applied for tetracycline removal from aqueous solution. Based on different characterization techniques, the material was found to possess a variety of surface functional groups on a porous structure and a pH point of zero charge (pHpzc) of 9.3. Adsorption of tetracycline (TC) was conducted under varying conditions, revealing significant effects of carbonization temperature, solution pH, adsorbent dose, ionic strength, contact time and initial concentration of TC on the biochar adsorption capacity. Kinetic data on TC adsorption were best described using the Elovich kinetic model, with an initial adsorption rate of 167.3 mg g−1 min−1. Isotherm data on adsorption of the desired biochar showed the best fit with the Temkin isotherm model, followed by the Langmuir model, displaying maximum adsorption capacity at 12.4 mg g−1. The electrostatic interactions between the charged biochar surfaces and certain fractions of TC were proposed as the major mechanism, together with H-bonding, pore-filling effect and π–π interaction. This study demonstrates great potential of H. undatus peel as a starting material to prepare an effective and reusable adsorbent in the removal of TC.

Using Extracted Sugars from Spoiled Date Fruits as a Sustainable Feedstock for Ethanol Production by New Yeast Isolates.

This study focuses on investigating sugar recovery from spoiled date fruits (SDF) for sustainable ethanol production using newly isolated yeasts. Upon their isolation from different food products, yeast strains were identified through PCR amplification of the D1/D2 region and subsequent comparison with the GenBank database, confirming isolates KKU30, KKU32, and KKU33 as Saccharomyces cerevisiae; KKU21 as Zygosaccharomyces rouxii; and KKU35m as Meyerozyma guilliermondii. Optimization of sugar extraction from SDF pulp employed response surface methodology (RSM), varying solid loading (20-40%), temperature (20-40 °C), and extraction time (10-30 min). Linear models for sugar concentration (R1) and extraction efficiency (R2) showed relatively high R2 values, indicating a good model fit. Statistical analysis revealed significant effects of temperature and extraction time on extraction efficiency. The results of batch ethanol production from SDF extracts using mono-cultures indicated varying consumption rates of sugars, biomass production, and ethanol yields among strains. Notably, S. cerevisiae strains exhibited rapid sugar consumption and high ethanol productivity, outperforming Z. rouxii and M. guilliermondii, and they were selected for scaling up the process at fed-batch mode in a co-culture. Co-cultivation resulted in complete sugar consumption and higher ethanol yields compared to mono-cultures, whereas the ethanol titer reached 46.8 ± 0.2 g/L.

Experimental analysis and modeling of aprepitant (an antiemetic drug for chemotherapy) solubility in subcritical water with/without co-solvent

This action described the experimental equilibrium solubility of aprepitant (APT), an antiemetic drug for chemotherapy, in subcritical water (SW) with/without ethanol as co-solvent, acquired through a static method between 298.15 and 393.15 K and 0–15 % (w/w) of ethanol and the constant pressure of 10 bar. The mole fraction of APT was obtained in the range of 0.39×10−4 to 9.10×10−4 while its mole fraction by cosolvent varied from 0.75×10−4 to 22.98×10−4. The obtained results represented the significant effect of solvent temperature on the solubility of APT. For both studied systems, the solubility data was successfully correlated with two well-known semi-empirical temperature-based models, namely the linear and modified Apelblat models. Results from applying statistical criteria exhibited that the modified Apelblat model had the highest accordance with experimental data. Finally, using the obtained correlation results, the apparent thermodynamic analysis including enthalpy, entropy, and Gibbs free energy of dissolution for APT dissolved in SW was obtained.

Demographic and net primary productivity dynamics of primary and secondary tropical forests in Southwest China under a changing climate

AbstractTropical forests are major carbon sinks on the Earth's land surface. However, our understanding of how the demographic rate and carbon sink capacities of tropical forests respond to climate change remains limited. In this study, we investigated the impacts of environmental drivers on forest growth, mortality, recruitment, and stem net primary productivity (NPPstem) over 16 years at five tropical forest plots in Xishuangbanna, Southwest China. These plots are along a successional gradient spanning three tropical secondary forests (tropical secondary forest‐1 [TSF‐1], tropical secondary forest‐2 [TSF‐2], and tropical secondary forest‐3 [TSF‐3]) and two primary forests (tropical rainforest [TRF] and tropical karst forest [TKF]). Our results showed that early successional secondary forests (TSF‐2 and TSF‐3) had higher diameter growth rates and relative mortality rates. An extreme drought event during 2009–2010 reduced the growth rate, relative recruitment rate, and NPPstem for most plots while increasing mortality in early successional forest plots. We observed significant negative effects of maximum temperature (Tmax) on NPPstem and diameter growth rate across all plots. Additionally, we found that precipitation had significant positive effects on diameter growth rate across all plots. Furthermore, tree mortality increased with rising Tmax, whereas precipitation significantly enhanced tree recruitment. Our findings highlight the vulnerability of tree growth, mortality, recruitment, and productivity in tropical forests to extreme drought events in Southwest China. Continued climate warming and more frequent droughts will induce higher mortality rates and impede growth, thus reducing the carbon sink capacity of tropical forests, especially in early successional stage tropical secondary forests.

Effects of temperature gradient on functional fruit traits: an elevation-for-temperature approach

Fruit traits mediate animal-plant interactions and have to a large degree evolved to match the sensory capacities and morphology of their respective dispersers. At the same time, fruit traits are affected by local environmental factors, which may affect frugivore-plant trait match. Temperature has been identified as a major factor with a strong effect on the development of fruits, which is of serious concern because of the rising threat of global warming. Nonetheless, this primarily originates from studies on domesticated cultivars in often controlled environments. Little is known on the effect of rising temperatures on fruit traits of wild species and the implications this could have to seed dispersal networks, including downstream consequences to biodiversity and ecosystem functioning. In a case study of five plant species from eastern Madagascar, we addressed this using the elevation-for-temperature approach and examined whether a temperature gradient is systematically associated with variation in fruit traits relevant for animal foraging and fruit selection. We sampled across a gradient representing a temperature gradient of 1.5–2.6 °C, corresponding to IPCC projections. The results showed that in most cases there was no significant effect of temperature on the traits evaluated, although some species showed different effects, particularly fruit chemical profiles. This suggests that in these species warming within this range alone is not likely to drive substantial changes in dispersal networks. While no systemic effects were found, the results also indicate that the effect of temperature on fruit traits differs across species and may lead to mismatches in specific animal-plant interactions.

Calibration of Thermal Viscoelastic Material Models for the Dynamic Responses of PVB and SG Interlayer Materials.

Laminated glass interlayer materials polyvinyl butyral (PVB) and SentryGlas® (SG, kuraray, Houstan, TX, USA) exhibit thermal viscoelastic behavior under dynamic tensile loading. Significant temperature and strain rate effects on the behavior of these interlayer materials pose a challenge for accurately modeling the dynamic response of laminated glass. Many researchers have simplified their approaches by modeling the response of the interlayer material using a bilinear approximation or established hyperelastic models. However, temperature and strain rate effects can be captured using the three-network viscoplastic (TNV) model. Therefore, the objective of this study is to calibrate material models for the thermal viscoelastic dynamic responses of PVB and SG interlayer materials. Uniaxial tensile tests were performed at strain rates of 2, 20, and 45 s-1 and temperatures of 0, 23, and 60 °C, and material models were calibrated using the experimental data. Finite element analysis using the calibrated material models successfully predicted the dynamic responses of PVB and SG under the experimental test conditions within a 10% error margin. This suggests that the calibrated models using the TNV model represent significant improvements over existing approaches to modeling the dynamic response of laminated glass. Similar procedures can be applied to other thermoplastics, laying the groundwork for establishing a standard calibration guide.

Quantification of PLA degradation in the melt phase using a parallel plate rheometer

Bioplastics like poly(lactic acid) or PLA have received significant attention over the last years, triggered by global environmental and climate concerns linked to the use of petroleum-based plastics. However, the ester bonds in PLA that are responsible for its biodegradable character are also vulnerable linkages during polymer processing. Melt processing of polymers typically involves high temperatures and shear loading. Hence, understanding degradation of PLA in the melt phase is crucial to minimize the molecular weight decrease, since it is directly linked to deterioration of mechanical, thermal and rheological properties. In this study, we performed a 24 full factorial design to investigate melt-phase degradation using a parallel plate rheometer. We investigated the effect of four parameters on the molecular weight: moisture content in the PLA, processing temperature, residence time, and shear stress. In addition, we explored whether the percentage of d-isomer significantly influences the degradation, through selecting three PLA-grades with different optical purity. The results showed that moisture content is the dominant factor in the molecular weight decrease, followed by a significant effect of processing temperature. Notably, the significant interaction between moisture content and processing temperature highlights the importance of studying interaction effects, an aspect often overlooked in current literature. Moreover, only the effect of moisture content is influenced by the percentage of d-isomer, whereas the numerical values of other significant effects are similar across the three PLA-grades. The small, yet significant effect of residence time, along with the unexpected insignificant effect of shear stress, may be explained by the use of small amplitude oscillatory deformations in a parallel plate rheometer as testing method in this study. In conclusion, the findings of this study offer polymer processors and researchers valuable insights, which can help with the selection and prediction of processing conditions that minimize degradation, ultimately saving time and raw materials during production.

Optimizing Lithium-Ion Battery Performance: Integrating Machine Learning and Explainable AI for Enhanced Energy Management

Managing the capacity of lithium-ion batteries (LiBs) accurately, particularly in large-scale applications, enhances the cost-effectiveness of energy storage systems. Less frequent replacement or maintenance of LiBs results in cost savings in the long term. Therefore, in this study, AdaBoost, gradient boosting, XGBoost, LightGBM, CatBoost, and ensemble learning models were employed to predict the discharge capacity of LiBs. The prediction performances of each model were compared based on mean absolute error (MAE), mean squared error (MSE), and R-squared values. The research findings reveal that the LightGBM model exhibited the lowest MAE (0.103) and MSE (0.019) values and the highest R-squared (0.887) value, thus demonstrating the strongest correlation in predictions. Gradient boosting and XGBoost models showed similar performance levels but ranked just below LightGBM. The competitive performance of the ensemble model indicates that combining multiple models could lead to an overall performance improvement. Furthermore, the study incorporates an analysis of key features affecting model predictions using SHAP (Shapley additive explanations) values within the framework of explainable artificial intelligence (XAI). This analysis evaluates the impact of features such as temperature, cycle index, voltage, and current on predictions, revealing a significant effect of temperature on discharge capacity. The results of this study emphasize the potential of machine learning models in LiB management within the XAI framework and demonstrate how these technologies could play a strategic role in optimizing energy storage systems.

High temperature and solar radiation in the Red Sea enhance the dissolution of crude oil from surface films

The Red Sea is a hotspot of biodiversity susceptible to oil pollution. Besides, it is one of the warmest seas on the Earth with highly transparent waters. In this study, we estimated the oil dissolution rates under natural sunlight spectra and temperature conditions using coastal oil slicks collected after the 2019 Sabiti oil spill in the Red Sea. Optical analyses revealed the significant interactive effect of sunlight and temperature in enhancing the dissolution of oil into dissolved organic matter (DOM). The highest oil dissolution rate (38.68 g C m−3 d−1) was observed in full-spectrum sunlight. Oil dissolution significantly enhanced total organic carbon (TOC) and polycyclic aromatic hydrocarbons (PAHs) in seawater. High nucleic acid (HNA) bacteria, likely the oil degraders, proliferated from 30 to 70 – 90% after 4 days. The heavier stable carbon isotopic composition of methane (δ13C-CH4) and lighter stable carbon isotopic composition of carbon dioxide (δ13C-CO2) indicate the putative role of bacterial processes in the natural degradation of crude oil. The results indicated that the combined effect of temperature and solar radiation enhanced the biological and photochemical dissolution of oil on the Red Sea surface.

Effects of canopy gaps on microclimate, soil biological activity and their relationship in a European mixed floodplain forest

Forest canopy gaps can influence understorey microclimate and ecosystem functions such as decomposition. Gaps can arise from silviculture or tree mortality, increasingly influenced by climate change. However, to what degree canopy gaps affect the buffered microclimate in the understorey under macroclimatic changes is unclear. We, therefore, investigated the effect of forest gaps differing in structure and size (25 gaps: single tree gaps up to 0.67 ha cuttings) on microclimate and soil biological activity compared to closed forest in a European mixed floodplain forest. During the investigation period in the drought year 2022 between May and October, mean soil moisture and temperature as well as soil and air temperature fluctuations increased with increasing openness. In summer, the highest difference of monthly means between cuttings and closed forest in the topsoil was 3.98 ± 9.43 % volumetric moisture and 2.05 ± 0.89 °C temperature, and in the air at 30 cm height 0.61 ± 0.35 °C temperature. For buffering, both the over- and understorey tree layers appeared as relevant with a particularly strong influence of understorey density on soil temperature. Three experiments, investigating soil biological activity by quantifying decomposition rates of tea and wooden spatulas as well as mesofauna feeding activity with bait-lamina stripes, revealed no significant differences between gaps and closed forest. However, we found a positive significant effect of mean soil temperature on feeding activity throughout the season. Although soil moisture decreased during this period, it showed no counteracting effect on feeding activity. Generally, very few significant relationships were observed between microclimate and soil biological activity in single experiments. Despite the dry growing season, decomposition rates remained high, suggesting temperature had a stronger influence than soil moisture. We conclude that the microclimatic differences within the gap gradient of our experiment were not strong enough to affect soil biological activity considerably.

Effect of incubation temperature on identification of key odorants of sewage sludge using headspace GC analysis

Currently, headspace gas chromatography-mass spectrometry is a widely used method to identify the key odorants of sludge. However, the effect of incubation temperature on the generation and emission of key odorants from sludge was still uncertain. Thus, in this paper, headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace gas chromatography-coupled ion mobility spectrometry (HS-GC-IMS) were carried out to analyze the volatiles emitted from the sludge incubated at different temperatures (30 °C, 50 °C, 60 °C, and 80 °C). The results indicated that the total volatile concentration of the sludge increased with temperatures, which affected the identified proportion of sludge key odorants to a certain extent. Differently from the aqueous solutions, the variation of volatile emission from the sludge was inconsistent with temperature changes, suggesting a multifactorial influence of incubation temperature on the identification of sludge odorants. The microbial community structure and adenosine triphosphate (ATP) metabolic activity of the sludge samples were analyzed at the initial state, 30 °C, and 80 °C. Although no significant effect of incubation temperature on the microbial community structure of the sludge, the incubation at 80 °C led to a noticeable decrease in microbial ATP metabolic activity, accompanied by a significant change in the proportion of odor-related microorganisms with low relative abundances. Changes in the composition and activity of these communities jointly contributed to the differences in odor emission from sludge at different temperatures. In summary, the incubation temperature affects the production and emission of volatiles from sludge through physicochemical and biochemical mechanisms, by which the microbial metabolism playing a crucial role. Therefore, when analyzing the key odorants of sludge, these factors should be considered.

Assessment of Physicochemical Properties of Orange Juice Concentrate Formulated with Pectin, Xanthan, and CMC Hydrocolloids.

Orange concentrate (OC) is one of the main raw materials in the nonalcoholic beverage industry. Considering the difference in orange varieties, preserving its natural quality is essential to yield a product with favorable attributes and physical stability. Thus, the present study is aimed at assessing the effect of pectin, xanthan, and carboxymethyl cellulose (CMC) in a concentration range of 0-0.2% (w/v) along with mixing temperature on Brix, pH, acidity, density, turbidity, and viscosity of OC and at calculating the model equation for each attribute. The results showed that, except for CMC, the influence of concentration, type, and amount of hydrocolloid on pH changes was insignificant. Adding each hydrocolloid individually, in pairs, or threes reduced the density, and the measured density was lower at a mixing temperature of 4°C. Also, it was observed that mixing temperature was the only factor influencing turbidity, and the values were significantly lower at 80°C compared to 4°C. A significant interaction effect of xanthan concentration and mixing temperature on the Brix was observed. Adding hydrocolloids, except pectin, resulted in a significant (p < 0.05) increase in viscosity, and xanthan had the greatest effect on the viscosity. A suitable model was designed using pectin and xanthan, pectin and CMC, and all three gums, resulting in a final OC product with high stability and improved physical and chemical attributes. The optimized values for Brix, pH, acidity, density, turbidity, and OC viscosity were achieved using 0.08% pectin, 0.19% xanthan, and 0.08% CMC at 80°C mixing temperature.

Physical environment and blood glucose level of diabetic patients: A cross-sectional study.

To determine the correlation between physical environment and blood glucose levels in diabetic patients. The quantitative, cross-sectional study was conducted from July to October 2022 at the Rejosari Pekanbaru Community Health Centre, Indonesia, and comprised diabetic patients of either gender with a disease history of at least 3 years. Environmental temperature was considered acceptable at 18-20°C, while environmental light was considered acceptable at 60-120 lux. Random blood glucose level <60mg/dL was taken as low, 70-130 mg/dL normal, and >140 mg/dL high. The correlation between physical environment and blood glucose level was worked out. Data was analysed using SPSS 20. Of the 125 subjects, 89(71.2%) were females and 36(28.8%) were males. There were 45 patients aged 56-65 years and 11(8.8%) were aged <11 years. Overall, 90(72%) patients had high random blood sugar and 35(28%) had normal level. The disease duration was <5 years in 79(63.2%) cases and >5 years in 46(36.8%). Of the 80(64%) patients who lived in an unacceptable living room temperature, 63(78.8%) had high random blood glucose levels (p=00042). Of the 73(58.4%) patients who lived in an unacceptable living room light, 59(80.8%) had high random blood glucose (p=0.016). A significant effect of temperature and light was found on blood glucose levels in diabetic patients.

Reassessment of Birch's Law on hcp‐Fe From Ultrasonic Sound Velocity Measurement and Implications on the Velocity Profiles of Earth's Inner Core

AbstractWe performed in situ X‐ray diffraction and ultrasonic sound velocity measurements on hcp‐Fe up to 15 GPa, 873 K in a multi‐anvil apparatus. The elastic moduli and their pressure and temperature derivatives were determined by fitting the velocity and density data to the third‐order finite strain equations, yielding KS0 = 169.0(57) GPa, KS0′ = 5.4(6), (∂KS/∂T)P = −0.031(3) GPa/K, G0 = 104.5(27) GPa, G0′ = 1.7(2), (∂G/∂T)P = −0.060(2) GPa/K. Within the experimental P‐T range, we find significant temperature effect on the density‐velocity (ρ − VP or S) relations and caution the use of the temperature‐independent Birch's law for extrapolation to core conditions. Furthermore, temperature‐induced velocity decrease is more significant in VS than in VP, offering a possible explanation for the high Poisson's ratio in the core. Extrapolations based on our results together with previous experimental data suggest that VP of hcp‐Fe aligns with PREM at Earth's core conditions, while Vs and density are approximately 10% and 2.7% higher than PREM, respectively.

An investigation on the relationship between the number of Barn Swallow (Hirundo rustica) and environmental parameters in Jelebu, Peninsular Malaysia

Swallows (Hirundo spp.) inhabit a variety of habitats in both tropical and temperate zones. Barn Swallows (Hirundo rustica), in particular, frequently roost in large numbers and construct mud nests on buildings, causing nuisance to humans. At the Glami Lemi Biotechnology Research Centre (GLBRC), which is located in Peninsular Malaysia, there are certain structures that are frequently utilised by a large number of swallows for perching and resting. This results in the defacement of the exterior walls caused by their droppings. Hence, the analysis presented in this paper delves into the factors influencing their presence and numbers. The objective of this study was to examine the fluctuations in the number of perched Barn Swallows and their relationship with three environmental parameters: temperature, relative humidity, and light intensity. Three hours of observation were conducted in two different sessions (i.e., morning and afternoon) three times per week for one year. The results showed that the number of Barn Swallows perched appeared to be stable throughout the year, except for November and December, when it increased tremendously and reached its peak. A Spearman rank analysis was conducted to investigate the correlation between the number of swallows perched and the environmental parameters. The analysis was restricted to only periods when the birds were present. A significant effect of relative humidity and temperature was observed for the morning session, promoting the relationship between the environmental parameters and the perching/resting behaviour of this species. This situation is parallel with the afternoon session, where all three environmental parameters showed a significant effect on swallows' numbers. This study not only provides valuable information to the GLBRC's management to effectively anticipate appropriate steps to mitigate the influx of Barn Swallows but also enhances our knowledge of the perching/resting behaviour of this species.

The influence of moisture transport processes on the stable isotopic compositions in precipitation on the South slope of the Himalayas

Understanding spatiotemporal variations in stable isotopes in precipitation (ẟ18O and ẟD) on the south slope of the Himalayas is crucial for comprehending moisture variations reaching the Tibetan Plateau (TP). Here, we analyze these variations at seven stations in Nepal spanning altitudes from 102 m to 5050 m above sea level in 2017. Our findings show no significant temperature or precipitation amount effect on isotopes, with synoptic precipitation exerting a strong influence. Non-monsoon precipitation primarily originates from the vicinity of the Koshi River basin and the Ganges River, while during the monsoon, the Bay of Bengal, the Koshi River basin, and the Ganges River contribute, with minimal input from the Arabian Sea. Convective activities significantly regulate inner-seasonal precipitation δ18O, with strong convection associated with low isotopic values. Increasing altitude leads to substantial differences in δ18O values, indicating modulation by higher condensation levels and lower temperatures. These findings underscore the impact of regional moisture transport on precipitation isotopic variability and offer insights into interpreting paleo-isotope records in the Indian Summer Monsoon region.

Environmental (and Random?) Sex Determination in Endangered and Invasive Phelsuma Geckos

Introduction: Sex is a fundamental characteristic of an individual. It is therefore puzzling why in some systems sex is precisely determined by a genotype, while in others it is influenced by the environment or even subtle, not to say random, factors. Some stochasticity in sex determination would be expected if environmental conditions did not have a large sex-specific effect on fitness. Although data are only available for a small fraction of species, geckos show exceptional variability in sex determination. Methods: We tested the effects of three incubation temperatures on sex ratio and adult body size in the invasive gecko Phelsuma laticauda and the vulnerable gecko Phelsuma nigristriata. Results: We document temperature-dependent sex determination (TSD) in both species. Only females hatched at a low temperature (24°C), whereas male production peaked at an intermediate temperature (28°C) and declined, at least in P. laticauda, again at the highest temperature (31°C). Interestingly, full siblings hatched from eggs glued together during the incubation at temperatures producing both sexes are often of the opposite sex. We found no significant effect of incubation temperature on adult body length. Conclusions: Documentation of TSD in the day geckos has implications for conservation practice in environmental management of endangered species or eradication of invasive species. However, it appears that a very subtle (random?) factor may also be involved in their sex determination. In line with this, we found no significant effect of incubation temperature on adult body length.