Dry Environmental Conditions Research Articles

Using Microalgae as a Good Motivator of Ossimi Lamb's Health and Growth

ABSTRACTIn tropical and subtropical countries like Egypt, sheep breeding faces environmental thermal stress, especially during the summer when air temperature and humidity are very high. Using Microalgae as an alternative feedstuff can significantly improve sheep growth, health and oxidative status. Therefore, this study aimed to evaluate the effect of consuming two different species of microalgae: Spirulina platensis (SP) and Chlorella vulgaris (C. vulgaris) on the following: growth performance, oxidative status, kidney and liver function, serum Glu, proteins and lipids profile and haematological parameters under hot dry environmental conditions. A total of 32 Ossimi male lambs were divided randomly into four equal groups (n = 8), (G1) was fed the control diet, (G2) was supplemented with S. platensis, (G3) was supplemented with a combination between (S. platensis and C. vulgaris) and (G4) was supplemented C. vulgaris. The results of our study revealed that microalgae supplementation significantly (p ≤ 0.05) enhanced lamb's growth, liver and kidney function, levels of serum immunoglobulin IgG, glutathione peroxidase (GPX) and haematological parameters. Moreover, the levels of thyroid hormones and serum proteins profile were significantly increased in all treated lambs compared to the control group. Our research revealed that including microalgae in sheep's feed can enhance their immune system, promote growth and enhance their general health by mitigating the harmful effects of heat and oxidative stress.

Will climate change constrain the altitudinal range of threatened species? Experimental evidence from a biodiversity hotspot.

A fundamental goal in ecology and evolution is to explain the factors that shape species' abundance and range limits. Evaluating the performance of early life-stages across an altitudinal gradient can be valuable for understanding what factors shape range limits and for predicting how plant species may respond to climate change. To experimentally evaluate the presence of local adaptation in a threatened palm (Euterpe edulis) at early life-stages, we reciprocally sowed seeds at two contrasting elevations. In addition, to evaluate the effect of seed predation on E. edulis seed germination and seedling establishment, seed addition experiments were conducted at three different elevations. Our results showed no evidence of local adaptation in the early life-stages for the two E. edulis populations. We observed lower germination and seedling performance of both E. edulis populations at the low-elevation site. The exclusion of seed predation increased seedling establishment across all elevations. Seed predation and dry soil conditions were the main factors that constrained seedling establishment at the upper altitudinal limit and at the lower elevation, respectively. Climate change in the study area will result in warmer and drier environmental conditions. The lack of local adaptation and the lower performance of both E. edulis populations in warm and dry conditions, combined with a higher seed predation at the upper altitudinal limit, might cause an altitudinal range contraction, increasing the vulnerability of this threatened species to climate change.

Assessment of Tamarind Seed Polysaccharide (TSP) and Hyaluronic Acid (HA) Containing Ophthalmic Solution to Maintain Tear Osmolarity, Ocular Surface Temperature (OST) and Tear Production.

The enhancement of ocular drug delivery is achieved by using biopolymer carriers in liquid ophthalmic preparations. Using natural polysaccharides to formulate ocular medications is attractive because they are economical and readily available. The primary goal of the study was to assess the safety and effectiveness of Tamarind seed polysaccharide (TSP)/Hyaluronic acid (HA) containing Rohto eye drops (TSP/HA drops) in alleviating the signs and symptoms of dry eye disease (DED) under dry environmental conditions using controlled environmental chamber (CEC). 12 participants were subjected to harsh environmental conditions in a CEC with a relative humidity (RH) of 5% and an ambient temperature of 21°C. TSP/HA drops were used in the two treatment modalities, protection (drops instilled before exposure to the dry environment and relief (drops instilled after exposure to the dry environment. Before and after administering drops, patients undergo screening for ocular symptoms, tear osmolarity, ocular surface temperature (OST), and tear production using the ocular Surface Disease Index questionnaire (OSDI), OcuSense TearLab Osmometer, FLIR System ThermaCAM P620, and phenol red test (PRT) respectively. Tear production was calculated by the Tear Function Index test (TFI). Before (protection) and after (relief) exposure to the dry environment, TSP/HA resulted in a mean tear osmolarity of 296.0 mOsm/L and 292.0 mOsm/L, with no significant statistical difference. The presence of TSP/HA in both protection and relief modes led to an increase in tear production. TSP/HA drops did not significantly affect OST compared to the absence of TSP/HA drops at 5% RH. There was a significant increase in mean symptom score from 14 at 40% RH to 128 at 5% RH (p=0.003). A substantial reduction in symptoms was found in both protection (before exposure) (35) (p=0.003) and relief (after exposure) (50) (p=0.005) compared to when no drop was used. It was apparent that using TSP/HA for protection was superior to relief for osmolarity and eye comfort. To optimise the therapeutic efficacy of TSP/HA, it is advisable to instruct patients to administer it before exposure to dry atmospheric conditions. The small sample size limits the ability to generalize the findings. Future studies should evaluate the tear supplement with a larger sample to improve statistical power.

An investigation on tribology performance of Abutilon Indicum fibre reinforced polymer composites

This research work investigates the tribological characteristics of Abutilon Indicum Fiber (AIF) reinforced composites with epoxy as the binding agent. The Abutilon Indicum fiber reinforced composites were manufactured by compression molding technique. These composites were fabricated by varying the fiber volume fraction ranging from 5%, 10%, 15% and 20% respectively and considering the fiber length as a fixed factor due to its short length. This research paper illustrates the effects of different fiber volume fractions (5,10,15 and 20%) on the tribological properties such as Specific wear rate (SWR) and Coefficient of friction (µ) of Abutilon Indicum fiber reinforced composites. Sliding wear tests were carried out under dry environment conditions with pin-on-disc wear testing machine. The experiments were performed for each composite with different combinations of testing parameters, sliding loads (10, 20 and 30 N); sliding distances (1,2 and 3 km); sliding speeds (1,2 and 3 m/s). Shore D hardness of 78.22 is determined to be higher for 15% volume fraction of AIF composites. Results conclude that the addition of AIFs in these composites enhanced the tribological performance with good wear resistance in relation with the pure epoxy-based composites with 15% volume fraction of AIFs displaying best results with higher resistance to wear at various operating conditions. Composites produced with 20% volume fraction displays the effects of fiber agglomeration which in turn has an inverse effect on hardness; limits the wear resistance with higher friction and wear rate and such results agree well with the wear debris, pits and contact patches in micrographs. Optimal fiber volume fraction of 15% was suggested in fabrication of composites for usage of AIFs as friction material.

The euphyllophytes of a new Givetian plant assemblage from the eastern Anti-Atlas, Morocco

The Middle Devonian is a transitional period for the first vascular plants, which acquire modern vegetative and reproductive structures, diversify considerably and, within the euphyllophytes, evolve the first representatives of modern plant groups, the monilophytes and lignophytes. However, the dynamics of this diversification across the different paleocontinents remains obscure, particularly within Gondwana. The upper Givetian locality of Oum el Jerane, in southeastern Morocco, has yielded a new assemblage of anatomically preserved plant remains whose description contributes to a better understanding of the floras of the northern margin of Gondwana during the Middle Devonian. The euphyllophytes include one iridopterid, Arachnoxylon minor, two cladoxylopsids, one of which represents the new genus Jerana, and two aneurophytales affiliated with the genus Triloboxylon. The cladoxylopsid remains from Oum el Jerane correspond to relatively small plants compared to the well-known coeval cladoxylopsids of Laurussia. Compared to the taxonomic composition of the four phytochoria recently defined for the Middle Devonian, the Oum el Jerane plant assemblage corresponds to the ‘subtropical’ phytochorion, which is close to the ‘Laurussia’ phytochorion, but which would correspond to drier environmental conditions.

Efficacy ofhydroxypropyl-guar dropsin improving tear film index and ocular surface dynamicsusing two treatment methods under a controlled desiccating environment.

This study aimed to assess the efficacy of hp-guar eye drops on tear film index and ocular surface dynamics under desiccating conditions using protection and relief treatment modalities. The 12 normal, non-dry eye participants were subjected to adverse environmental conditions using a Controlled Environment Chamber (CEC) where the relative humidity (RH) was 5% and the ambient temperature was 21°C. The participants were screened for ocular symptoms, tear osmolarity, ocular surface temperature (OST), tear production using the Ocular Surface Disease Index questionnaire (OSDI), OcuSense TearLab Osmometer, FLIR System ThermaCAM P620, and Schirmer strips. Tear production was calculated by the Tear Function Index test (TFI). The mean tear film osmolarity decreased significantly from 296mOsm/L at 40% RH to 285mOsm/L at 5% RH (p = 0.01). Conflicting responses were seen for osmolarity in protection and relief. Mean tear osmolarity was significantly higher in the protection method in comparison to the relief method (p = 0.005). The mean TFI increased from 557 at 40% to 854 at 5% (p = 0.02). A significant increase in TFI was observed in the relief method in comparison with both 40% (p = 0.001) and 5% (p = 0.04). In the relief method, the mean TFI score went up to 1139 when hp-guar was installed. A significant improvement in ocular comfort was experienced in both the protection (p = 0.041) and relief (p = 0.010) methods at 5% RH. The instillation of hp-guar drops in the relief method resulted in a significant reduction in OST. The mean OST dropped to 33.01 ºC, significantly lower than the recorded OST for both normal (p = 0.040) and dry (p = 0.014) environmental conditions. Hp-guar drops significantly improve tear film parameters under a desiccating environment, however, tear film parameters respond differently to the management modalities. In the protection method, tear film osmolarity was protected against a dry environment, while in the relief mode, an improvement in tear production and a decrease in ocular surface temperature were seen. Hp-guar performance could be maximized for the management of exposure to adverse environments by using a treatment protocol that targets the most affected parameters in each group of patients. Using CEC has the potential to provide researchers with a readily available method to evaluate the efficiency of tear supplementation.

Niche analyses and the potential distribution of four invasive bumblebees worldwide.

The introduction of bees for agricultural production in distinct parts of the world and poor management have led to invasion processes that affect biodiversity, significantly impacting native species. Different Bombus species with invasive potential have been recorded spreading in different regions worldwide, generating ecological and economic losses. We applied environmental niche and potential distribution analyses to four species of the genus Bombus to evaluate the similarities and differences between their native and invaded ranges. We found that B. impatiens has an extended environmental niche, going from dry environmental conditions in the native range to warmer and wetter conditions in the invaded range. Bombus ruderatus also exhibited an extended environmental niche with drier and warmer conditions in the invaded range than in its native range. Bombus subterraneus expanded its environmental niche from cooler and wetter conditions in the native range to drier and warmer conditions in the invaded range. Finally, B. terrestris showed the most significant variation in the environmental niche, extending to areas with similar and different environmental conditions from its native range. The distribution models agreed with the known distributions for the four Bombus species, presenting geographic areas known to be occupied by each species in different regions worldwide. The niche analysis indicate shifts in the niches from the native to the invaded distribution area of the bee species. Still, niche similarities were observed in the areas of greatest suitability in the potential distribution for B. ruderatus, B. subterraneus, and B. terrestris, and to a lesser degree in the same areas with B. impatiens. These species require similar environmental conditions as in their native ranges to be established in their introduced ranges. Still, they can adapt to changes in temperature and humidity, allowing them to expand their ranges into new climatic conditions.

Evaluation of therapeutic efficacy of Emustil drops for ocular discomfort and tear film osmolarity using different treatment management modes under dry environmental conditions

BackgroundWe aimed to check the efficacy of Emustil (oil in water emulsion) drops on tear film index and ocular surface dynamics in dry environments through protection and relief treatment modalities.MethodsThe subjects were exposed to a dry environment using a Controlled Environment Chamber (CEC) where the relative humidity (RH) was 5% and the temperature was 21 °C and screened for ocular symptoms, tear osmolarity, ocular surface temperature (OST) and tear production using ocular Surface Disease Index questionnaire (OSDI), OcuSense TearLab Osmometer, FLIR System ThermaCAM P620 and Schirmer strips/phenol red test respectively. Tear production was calculated by the Tear Function Index test (TFI).ResultsThe mean tear film osmolarity decreased significantly from 296.8 mOsm/l at 40% RH to 291 mOsm/l at 5%. (p = 0.01). Instillation of Emustil resulted in a significant increase in tear osmolarity in the relief method compared with osmolarity seen at 5% RH when no drop was used. The mean PRT value decreased from 26 ± 9 in normal conditions (40% RH) to 22 ± 4 mm in dry conditions (5% RH). Emustil drops did not induce any significant change in tear production in the PRT test. No significant change was found in OST following exposure to 5% RH. OST did not show a statistically significant change with the emulsion when used for relief (p > 0.05). The mean score of ocular discomfort observed was 70 at 5% RH. Still, the instillation of the oil-in-water emulsion (Emustil) resulted in a noticeable decrease in visual discomfort to 37 (p = 0.00) in protection and 59 in relief (p = 0.05). Emustil drops substantially improved tear film parameters under a desiccating environment, however, tear film parameters respond differently to the management modalities. In the protection method, tear film osmolarity was protected against a dry environment, while in the relief mode, tear production was improved.ConclusionCEC allows for a thorough evaluation of tear film parameters and dry eye treatment protocols in labs, providing greater confidence when applying them to patients. In addition, our study showed that Emustil not only provides protection and relief for dry eyes but also helps to maintain ocular homeostasis in desiccating environments. This indicates a promising potential for improving dry eye treatment protocols.

Diatom-based indications of an environmental regime shift and droughts associated with seasonal monsoons during the Holocene in Biển Hồ maar lake, the Central Highlands, Vietnam

The interactions of the different monsoon systems across Southeast Asia create extreme climate phenomena. Central Vietnam, located near the centre of this transitional region, has encountered numerous effects. As a result, its sediments from lakes or speleothems are valuable archives for interpreting past climate variability. However, there is still a lack of high-resolution paleoenvironmental and palaeoclimatic reconstructions during the Holocene in Vietnam. Our study presents a paleoenvironmental diatom-based record of sediment cores collected from Biển Hồ maar lake (14°03′N, 108°00′E) in the Central Highlands of Vietnam covering nearly the entire Holocene. Based on changes in diatom assemblages in the sediment sequence, we identified two periods of the Early Holocene (~11,700–7800 cal BP) and the Mid- to Late-Holocene (~7800–360 cal BP), which mark a remarkable shift in the environment around Biển Hồ. Alternations of key diatom species during the Early Holocene indicate intensity variations between water-mixing and thermal stratification mechanisms in meso-eutrophic conditions. During the Mid- to Late-Holocene, the complete dominance of Aulacoseira granulata var. granulata implies year-round destratification and intense mixing of the lake water column in a permanently eutrophic environment. Its morphological variability reveals intervals of dry environmental conditions driven by pronounced droughts across the Asian continent.

Genetic background of juniper (Juniperus spp.) consumption predicted by fecal near-infrared spectroscopy in divergently selected goats raised in harsh rangeland environments

BackgroundJunipers (Juniperus spp.) are woody native, invasive plants that have caused encroachment problems in the U.S. western rangelands, decreasing forage productivity and biodiversity. A potential solution to this issue is using goats in targeted grazing programs. However, junipers, which grow in dry and harsh environmental conditions, use chemical defense mechanisms to deter herbivores. Therefore, genetically selecting goats for increased juniper consumption is of great interest for regenerative rangeland management. In this context, the primary objectives of this study were to: 1) estimate variance components and genetic parameters for predicted juniper consumption in divergently selected Angora (ANG) and composite Boer x Spanish (BS) goat populations grazing on Western U.S. rangelands; and 2) to identify genomic regions, candidate genes, and biological pathways associated with juniper consumption in these goat populations.ResultsThe average juniper consumption was 22.4% (± 18.7%) and 7.01% (± 12.1%) in the BS and ANG populations, respectively. The heritability estimates (realized heritability within parenthesis) for juniper consumption were 0.43 ± 0.02 (0.34 ± 0.06) and 0.19 ± 0.03 (0.13 ± 0.03) in BS and ANG, respectively, indicating that juniper consumption can be increased through genetic selection. The repeatability values of predicted juniper consumption were 0.45 for BS and 0.28 for ANG. A total of 571 significant SNP located within or close to 231 genes in BS, and 116 SNP related to 183 genes in ANG were identified based on the genome-wide association analyses. These genes are primarily associated with biological pathways and gene ontology terms related to olfactory receptors, intestinal absorption, and immunity response.ConclusionsThese findings suggest that juniper consumption is a heritable trait of polygenic inheritance influenced by multiple genes of small effects. The genetic parameters calculated indicate that juniper consumption can be genetically improved in both goat populations.

Plant biodiversity responds more strongly to climate warming and anthropogenic activities than microbial biodiversity in the Qinghai–Tibetan alpine grasslands

Abstract Biodiversity serves as the fundamental underpinning for ecosystem functions and services. As a result of human‐induced global change, there is a growing awareness of the substantial alterations in terrestrial above‐ground biodiversity, particularly within alpine regions. However, it remains uncertain whether below‐ground biodiversity will exhibit similar responses, both in terms of magnitude and manner, to anthropogenic global changes as above‐ground biodiversity. Here, we conducted a meta‐analysis to assess the impacts of warming, nutrient addition and grazing on plant and soil microbial biodiversity in alpine grasslands on the Qinghai–Tibetan Plateau, which are known to be climate‐sensitive and vulnerable. The analysis included 819 experimental observations from 152 studies, focussing on species richness, Shannon diversity and Pielou's evenness. We found that plant biodiversity exhibited greater sensitivity to climate warming and anthropogenic activities compared with soil microbial biodiversity. Specifically, plant richness and Shannon diversity were reduced by warming and nutrient addition, while plant evenness was increased by grazing. However, only microbial richness was increased by grazing and microbial evenness was increased by warming slightly. The responses of biodiversity to climate warming and anthropogenic activities were modulated by multiple factors. Specifically, the negative effects of warming on plant biodiversity were more pronounced in long‐term experiments under warmer or drier environmental conditions. The negative effects of nitrogen addition on biodiversity were enhanced by the intensity and duration of nitrogen treatment. Appropriate intensity and frequency of grazing were beneficial to sustaining plant biodiversity. Soil microbial biodiversity was weakly regulated, where bacterial Shannon diversity was more sensitive to nutrient addition, while fungal species richness was sensitive to grazing. Synthesis. Our findings reveal a mismatch between above‐ground plant and below‐ground microbial biodiversity in response to climate warming and anthropogenic activities in alpine grasslands, with plant biodiversity being more sensitive. In the context of future global change, plant biodiversity may be at greater risk than soil microbial biodiversity. In addition, biodiversity responses of different experimental and environmental conditions should be distinguished, and more attention is needed on biodiversity conservation in alpine steppe, or areas with warmer and drier environmental conditions, high‐intensity fertilization or heavy grazing.

Climatology and pre-convection environmental conditions of dry and wet thunderstorm high winds over eastern China

Thunderstorm high wind (THW) is defined as a kind of convective weather phenomenon with a maximum wind gust speed not less than 17.2 m·s−1 over China. It is a sudden, damaging, but common convective weather phenomenon during the warm seasons of China. By adopting a kernel density estimation (KDE) for the THWs during warm seasons (March–September) of 2010–2019 over eastern China and the European Centre for Medium-Range Weather Forecasts Reanalysis v5 (ERA5) dataset, the dry and wet THWs usually with different mechanisms are objectively obtained, and climatology and pre-convection environmental conditions investigated. KDE shows the total precipitable water (TPW) of 38 mm can be used as the threshold for distinguishing dry THWs from wet ones. Dry THWs mainly concentrate in North China and Yunnan province, while wet ones mainly concentrate in South China. West of Hebei province has high frequencies for both dry and wet THWs. A comparison of pre-convection environmental conditions shows dry THWs mainly occur under environmental conditions with lower saturation at both the middle-lower and upper layers, while wet ones usually have relatively lower saturation at the middle-lower layers. The instability of wet THWs can be well characterized by the most unstable lifted index (MULI) and most unstable convective available potential energy (MUCAPE), while dry ones can be well depicted by the lower 500 hPa temperature caused higher temperature difference (DT85) or temperature lapse rate (TLR85) between 850 and 500 hPa. The 0–6-km vertical wind shear (SHR6) can distinguish dry THWs from wet ones better than SHR1. The typical difference can be comprehensively revealed by the representative soundings. The results provide objective references for understanding and forecasting THWs under dry and wet environmental conditions.

Climate and environmental changes recorded by aeolian sediment during the last glaciation in the western Qaidam Basin

Aeolian sediments are widely distributed in the Qaidam Basin (QB) on the northeastern Qinghai-Tibet Plateau (QTP) and are ideal carriers of information for studying the environmental evolution of the basin. However, due to factors such as dry denudation and glacier erosion, there is a lack of palaeo-aeolian sediment records in the late glacial period. This study applied quartz optically stimulated luminescence (OSL) dating to fluvial-aeolian sequences in the TLH profile, which were exposed by river downcutting in the Tora River. In addition, OSL ages were combined with grain size and chemical elements to explore the sedimentary and environmental changes in the late glacial period recorded by palaeo-aeolian sediments in the QB. The results show that aeolian sediment accumulated earlier than the last glacial period in the QB and that the QB experienced multiple alternations of drying and wetting during this period. From approximately 70.45 ka BP to 60.87 ka BP, thick aeolian sediment with noticeable cross-bedding developed in this location, suggesting relatively dry environmental conditions and intense sand activities. From 60.87 ka BP to 58.56 ka BP, the environmental proxies revealed two distinct layers of fluvial deposits, with relatively coarse average grain sizes and weak chemical weathering, indicating wetter conditions. This region experienced alternations of drying and wetting between 58.56 ka BP and 41.09 ka BP, resulting in an aeolian sand layer and a freeze-thaw folded layer. This research is a good supporter of climate and environmental changes in the last glaciation.

Female lizards (Eremias argus) reverse Bergmann's rule across altitude.

The evolution of body size within and among species is predicted to be influenced by multifarious environmental factors. However, the specific drivers of body size variation have remained difficult to understand because of the wide range of proximate factors that covary with ectotherm body sizes across populations with varying local environmental conditions. Here, we used female Eremias argus lizards collected from different populations across their wide range in China, and constructed linear mixed models to assess how climatic conditions and/or available resources at different altitudes shape the geographical patterns of lizard body size across altitude. Lizard populations showed significant differences in body size across altitudes. Furthermore, we found that climatic and seasonal changes along the altitudinal gradient also explained variations in body size among populations. Specifically, body size decreased with colder and drier environmental conditions at high altitudes, reversing Bergmann's rule. Limited resources at high altitudes, measured by the low vegetative index, may also constrain body size. Therefore, our study demonstrates that multifarious environmental factors could strongly influence the intraspecific variation in organisms' body size.

A modified Jarvis model to improve the expressing of stomatal response in a beech forest

AbstractThe Jarvis‐type model, which incorporates stress functions, is commonly used to describe the physiological behaviour of stomatal response in various vegetation species. However, the model has been criticized for its empirically formulated multiplicative equation, which may not accurately capture the mutual impact of intercorrelated stress factors, for example, vapour pressure deficit (VPD) and air temperature (Ta). This study proposed a modified Jarvis model that introduces reduction factors in the stress functions of VPD and Ta to provide the description of canopy conductance. We used sap flow data from a beech forest in the mid‐latitude region of Centre Europe to inversely estimate the canopy conductance with optimized stress functions. Our findings reveal that two recommended parameterization strategies for general deciduous broadleaf forest (DBF) significantly overestimated the transpiration rate, with a maximum value of ~2 mm/day on rainless days. This suggested that the beech forest exhibited a distinct stomatal response compared to the general DBF category. By applying boundary line analysis to fit the parameters, both the unmodified and modified Jarvis models provided better simulations of transpiration, with relatively high Nash‐Sutcliffe Efficiency (NSE) values of 0.75 and 0.77, respectively. These results indicated that modelling transpiration can be improved by refining the parameterization of canopy conductance, particularly for vegetation species with unique stomatal behaviours that deviated from the characteristics of their general vegetation type. The modified Jarvis model offers a more accurate description of canopy conductance and enhances the modelling of transpiration in vegetated areas, especially under dry environment conditions with relatively high VPD.

Using Deficit Irrigation Strategies and Organic Mulches for Improving Yield and Water Productivity of Mango under Dry Environment Conditions

Many techniques have been and are being made to find alternatives to water-saving practices. Among them, Partial root drying (PRD), one effective approach, plays a major role in reducing the harmful effects of water deficit stress. Field experiments were carried out on mango trees for a private farm in Egypt over the course of two years, 2020/2021 to 2021/2022, in an area with sandy soil, hot summer conditions, and cold and rainy winter conditions. In the experiment that was carried out, the experimental design included using different irrigation strategies (I1, 100% full irrigation “FI”; I2, 75% FI; I3, 50% FI; and I4 (PRD), 50% FI) in the main plot and different amounts of organic mulch in the soil (L0, no layers of organic soil mulch, used as a control; L1, a single layer of organic soil mulch; L2, two layers of organic soil mulch; and L3, three layers of organic soil mulch) in subplots of the main plot in order to inspect the impact of the treatments on yield, water productivity, and energy usage under arid conditions. To meet the study’s objective, two field experiments were carried out at a private farm. Our results demonstrate a general decrease in water stress and salt accumulation inside the root-zone area with PRD and L3. During the 2020/2021 and 2021/2022 seasons the PRD strategy increased fruit yields by 3.7 and 7.3% and water productivity by 51.9 and 53.1%, respectively, compared with the control treatment (I1) while reducing the amount of applied irrigation water by 50%. The PRD strategy along with organic mulching showed superior results with respect to increasing mango yields and water productivity. In general, PRD can be used as a good technique to save water and energy by up to 50% while enhancing productivity, ultimately improving mango yields under arid climatic conditions. Thus, it may prove a good adaptation strategy for current and future water shortage scenarios involving climate change.

Evaluation of Therapeutic Capability of Emustil Drops against Tear Film Complications under Dry Environmental Conditions in Healthy Individuals.

Background and Objectives: Dry eye disease (DED) is a multifactorial ailment of the tears and ocular surface. The purpose of this study was to assess the tear film physiology under controlled dry environmental conditions and compare the efficacy of oil-in-water emulsion drops on tear film parameters in protection and relief treatment modalities under low-humidity conditions. Emustil eye drops were used after exposure to a low-humidity environment in the relief method, whereas, in the protection method, the drops were applied before exposure to low humidity. Materials and Methods: 12 normal male subjects (mean age 34.0 ± 7.0 years) were exposed to ultra-dry environmental conditions. A number of tear film measurements were carried out under desiccating environmental conditions in a controlled environment chamber (CEC), where the chamber temperature sat at 21 °C with a relative humidity (RH) of 5%. Keeler's TearScope Plus and an HIRCAL grid were used to assess the tear break-up time and lipid layer thickness (LLT), and the evaporation rate was evaluated using a Servomed EP3 Evaporimeter. Results: LLT measurements showed that the dry environment affected LLT significantly (p = 0.031). The median grade of LLT dropped from grade 3 (50-70 nm) at 40% RH to grade 2 (13-50 nm) at 5% RH. A significant increase in LLT was seen after both modes of treatment, with a median LLT grade of 3 when the Emustil was used for both protection (p = 0.004) and relief (p = 0.016). The mean tear evaporation rate in normal environmental conditions (40%) was 40.46 ± 11.80 g/m2/h (0.11 µL/min) and increased sharply to 83.77 ± 20.37 g/m2/h (0.25 µL/min) after exposure to the dry environment. A minimal decrease in tear film evaporation rate was seen in relief; however, statistical tests showed that the decrease in tear film evaporation rate was not significant. Mean NITBUT dropped from 13.6 s at 40% RH to 6.6 s at 5% RH (p = 0.002). All NITBUT measurements at 5% RH (with or without the instillation of Emustil) were significantly lower than those at 40%. The instillation of Emustil at 5% RH resulted in a significant improvement in NITBUT for protection (p = 0.016) but this was not the case for relief (p = 0.0.56). Conclusions: A control environmental chamber (CEC) enables the analysis of tear film parameters comparable to those found in dry eye patients. This enables us to examine the capability of oil in emulsion drops to manage tear film disruption in healthy individuals. This study suggests that using Emustil oil-in-water emulsion before exposure to a dry environment should be advocated for people who work in dry environments.

Late Quaternary hydroclimatic variations in the hyper-arid Dunhuang Basin, northwestern China

The changes in paleoclimate and their driving mechanisms in northwestern (NW) China since the Late Quaternary remain unclear and controversial. This is due to the scarcity of relatively continuous sedimentary records with high-resolution chronological controls in this hyper-arid region. To address this gap, a new sedimentary record was drilled from Yitang Lake in the Dunhuang Basin of NW China, and used to reconstruct the long history of regional hydroclimatic changes since the Late Pleistocene. A comprehensive high-resolution geochronology of the upper part of the drilling core indicates a significant sedimentary hiatus between approximately 100 ka and 23 ka, likely due to the dry and harsh environmental conditions during the Last Glacial period (MIS 4 to MIS 2). Since then, the study area has experienced a relatively dry Late Glacial period (∼23–11 ka), gradually wetter early Holocene (∼11–8 ka), and moist mid-Holocene (∼8–5 ka), followed by a drying trend after approximately 5 ka. Hydrological variations in this area since the Late Quaternary were mainly controlled by changes in precipitation and glacier meltwater from the northeastern Tibetan Plateau. These alterations were ultimately regulated by shifts in atmospheric circulation patterns, as well as the dynamic interplay between the westerlies and the East Asian summer monsoon at both orbital and suborbital scales.

Different Aspects of Machinability in Turning of AISI 304 Stainless Steel: A Sustainable Approach with MQL Technology

Machining of AISI 304 austenitic stainless steel is considered to be difficult due to its structural aspects and low thermal conductivity, which leads to increased temperatures during machining. To overcome the challenges of machining AISI 304 stainless steel, several cooling and lubricating techniques have been developed. The main objective of this experimental study is to evaluate the different turning conditions of AISI304 stainless steel under dry and minimum quantity lubrication (MQL) environment conditions. The machining experiments were conducted using a two-level full factorial design method and utilized a TiC-coated cutting tool. The tool-tip temperature, cutting force and surface roughness were analyzed regarding three cutting parameters namely, cutting speed, feed rate and cutting depth. Also, chip macro-morphology was investigated to define the interaction at the tool-chip-workpiece region. The cutting medium affects the surface roughness significantly (more than 100%) for all cutting parameter values. In some environmental cutting conditions, high cutting speed provides 10% lesser surface roughness than low cutting speed parameters. Also, the cutting force decreases by 20% in low feed rate machining conditions. However, the effect of this parameter disappeared for cutting forces in high feed rates and low cutting depth conditions in both MQL and dry environments. Cutting speed was observed as the most influential factor on surface roughness, followed by feed rate. The depth of cut was the main parameter that caused the temperature to increase in the dry machining environment.

Cloud-scale dynamical and microphysical properties in contrasting monsoon environments from observations and simulations

Three distinct environmental regimes (moist-rainy monsoon, dry-intermittent-rainy monsoon and post-monsoon) based on atmospheric moist static energy and surface rainfall measurements over the rain shadow region of the Indian peninsula are investigated with large eddy simulation (LES) model and in situ cloud microphysics observations. Cloud condensation nuclei (CCN) number concentration measurement showed increased values for dry-intermittent-rainy monsoon and post-monsoon seasons and aerosol activation characteristics were distinct.The model simulation showed general features as deeper clouds with higher fractional cloud coverage and rain water formation for the moist-rainy monsoon environment compared to the dry-intermittent-rainy and post-monsoon environments. The highest ice water content in the mixed-phase region was noted for the moist-rainy monsoon case and conversion to rain water occurred through the melting of ice. Dry-intermittent-rainy and post-monsoon clouds have no rainwater in the model due to smaller droplet size and lower cloud depth. Cloud core buoyancy, latent heating and updraft velocity are relatively higher (except at the cloud-top level) for the dry-intermittent-rainy monsoon conditions compared to the moist-rainy monsoon conditions. A higher negative buoyancy (associated with latent cooling) at the cloud top curtails cloud growth in dry conditions. Convective mass flux and lateral entrainment rate have decreased with drier environmental conditions. This indicates that clouds are less diluted and mixed with the environmental air in the dry-intermittent-rainy conditions and thereby maintain higher liquid water content in the cloud core region.