Tajikistan, a mountainous country and a vital water tower for Central Asia, is becoming increasingly vulnerable to snow drought under climate change, threatening its snow- and glacier-fed streamflow. Yet, the impacts of snow drought on the regional hydrology remain insufficiently understood. In this study, we integrated multisource data, including the Fifth Generation European Centre for Medium-Range Weather Forecasts Atmospheric Reanalysis for Land Applications (ERA5-Land) data and hydrological station data, to systematically assess the snow drought patterns and their impacts on streamflow during 1950–2023. We identified snow drought events based on precipitation and snow fraction anomalies relative to climatological means and classified them into warm snow drought, dry snow drought, and warm&dry snow drought. The results revealed that snow drought was a recurrent phenomenon, occurring in 51.70% of the years during the study period, with warm&dry snow drought accounting for 21.90% of the total events. Both the frequency and severity exhibited pronounced spatial variability, largely governed by the elevation and snowfall fraction. Specifically, the frequency of warm snow drought was negatively correlated with the snowfall fraction, decreasing on average by 0.20 per unit increase in snowfall fraction, whereas the frequency of dry snow drought was positively correlated, increasing by 0.07 per unit increase. The streamflow analysis results demonstrated that snow drought typically reduced the warm-season discharge by 5.00%–18.00% in certain rivers, thereby exacerbating the water stress during the dry season. The results of this study advance our understanding by explicitly linking the types of snow drought to hydrological responses in Central Asia’s high mountains, providing a scientific basis for climate adaptation and sustainable water resource management in Tajikistan.
Chlorella is a promising biofuel source due to its high lipid accumulation, rapid growth, and suitability for inland cultivation. However, how the Paramecium bursaria Chlorella virus 1 (PBCV-1) influences its triacylglycerol (TAG) accumulation remains underexplored. This data article provides a detailed description of the dataset generated to investigate TAG accumulation profiles in Chlorella infected with PBCV-1. The data, collected via high-resolution epifluorescence microscopy of over 4000 single cells across a full lytic cycle, includes measurements of TAG accumulation, chlorophyll fluorescence, and nuclear morphology, along with extracellular nutrient concentrations to rule out nutrient stress as a confounding factor. This dataset can be reused by researchers to develop new image analysis algorithms, train machine learning models, investigate virus-host interactions, and inform the development of more cost-effective biofuel production strategies.
Computer applications to medicine. Medical informatics, Science (General)
Existence of cilia in the last eukaryotic common ancestor raises a fundamental question in biology: how the transcriptional regulation of ciliogenesis has evolved? One conceptual answer to this question is by an ancient transcription factor regulating ciliary gene expression in both uni- and multicellular organisms, but examples of such transcription factors in eukaryotes are lacking. Previously, we showed that an ancient transcription factor X chromosome-associated protein 5 (Xap5) is required for flagellar assembly in Chlamydomonas. Here, we show that Xap5 and Xap5-like (Xap5l) are two conserved pairs of antagonistic transcription regulators that control ciliary transcriptional programs during spermatogenesis. Male mice lacking either Xap5 or Xap5l display infertility, as a result of meiotic prophase arrest and sperm flagella malformation, respectively. Mechanistically, Xap5 positively regulates the ciliary gene expression by activating the key regulators including Foxj1 and Rfx families during the early stage of spermatogenesis. In contrast, Xap5l negatively regulates the expression of ciliary genes via repressing these ciliary transcription factors during the spermiogenesis stage. Our results provide new insights into the mechanisms by which temporal and spatial transcription regulators are coordinated to control ciliary transcriptional programs during spermatogenesis.
Yepes Jairo E., Hoyos Laureano R., Velosa Claudia L.
et al.
A thorough experimental program has been undertaken to assess the suction-controlled peak and residual shear strength responses of statically compacted, moderate plasticity clayey soil over a relatively wide range of suction states. The experimental program was accomplished via a servo/suction-controlled ring shear apparatus suitable for testing unsaturated soils under large deformations via the axis-translation technique. Results further substantiate the crucial role that has been observed to be played by the imposed matric suction on residual shear strength behaviour of compacted clayey soils. For the range of net normal stresses (0-200 kPa) and matric suction states (0-300 kPa) investigated, the increase in both peak and residual shear strength, with increasing matric suction, was found to be markedly nonlinear. Furthermore, a readily distinct correspondence was observed between the nonlinear nature of either peak or residual shear strength envelopes, with respect to increasing matric suction, and the very nature of the soil-water retention curve of the test soil. Results, in general, confirm that a conceptual residual shear strength framework for unsaturated soils, analogous to that postulated for peak shear strength, can be formulated with reasonable reliability.
<p>The Mediterranean basin, a recognized climate change hotspot, faces increasing hydroclimatic pressures, particularly from severe drought and precipitation events. To assess contemporary changes and potentially manage future impacts, it is crucial to understand the long-term context of this variability beyond the relatively short instrumental record. This study utilizes tree-ring records to reconstruct past hydroclimate in the Iberian Range of eastern Spain, a water-sensitive Mediterranean environment. We present a well-replicated tree-ring width chronology from <i>Pinus sylvestris</i> and <i>Pinus nigra</i> trees that calibrates and verifies significantly against cumulative instrumental precipitation over a 320 d period ending in June (<span class="inline-formula"><i>r</i></span> <span class="inline-formula">=</span> 0.749; <span class="inline-formula"><i>p</i></span> <span class="inline-formula"><</span> 0.01). The resulting 520-year reconstruction reveals substantial multi-centennial variability in precipitation and reveals an increase in the frequency and intensity of hydroclimatic extremes (both wet and dry) during the late 20th and early 21st centuries compared to the longer-term baseline. The reconstruction has a spatial representativeness centred over eastern and central Iberia and covaries with independent historical drought indices derived from rogation ceremony records during the late 18th and early 19th centuries. The documented intensification of hydroclimatic extremes is consistent with climate change projections and provides a baseline for evaluating ecosystem resilience and water resource vulnerability.</p>
Abstract The aim of this study was to develop a photothermal material modified with carbonization and ZnCl2 impregnation and supported by polyvinyl alcohol (PVA) for water purification using the waste coffee grounds. Scanning electron microscopy (SEM) characterization of the prepared material revealed that a significant surface modification was achieved due to the carbonization and ZnCl2 impregnation. X-ray diffraction analysis (XRD) pattern of the samples showed two broad peaks at 18.4° and 22.2°, this is due to the crystal planes of β-crystal phase structure, which indicates the existence of strong hydrogen bonds between the micro-structures and therefore less suspectable to chemical attack. Additionally, thermogravimetric analysis (TGA) result suggests a slight mass reduction between the temperature range of 65–75 °C implying the thermal stability of the prepared material. The produced modified material had a photothermal conversion efficiency of 74% and could produce vapor at a rate of 1.12 kg/m2h under 980 W/m2 irradiation at 1 sun. A significant reduction in Cu2+ ion concentration (83%), turbidity (91%), total dissolved solids (TDS) (61%), microbial load (95.6%), and total hardness (41.2%) were achieved. Therefore, waste coffee grounds can be considered as a future eco-friendly and low-cost candidate for water purification.
Samantha M. Wilcox, Catherine N. Mulligan, Carmen Mihaela Neculita
Mining waste represents a global issue due to its potential of generating acidic or alkaline leachate with high concentrations of metals and metalloids (metal(loid)s). Microbial-induced calcium carbonate precipitation (MICP) is an engineering tool used for remediation. MICP, induced via biological activity, aims to precipitate calcium carbonate (CaCO<sub>3</sub>) or co-precipitate other metal carbonates (MCO<sub>3</sub>). MICP is a bio-geochemical remediation method that aims to immobilize or remove metal(loid)s via enzyme, redox, or photosynthetic metabolic pathways. Contaminants are removed directly through immobilization as mineral precipitates (CaCO<sub>3</sub> or MCO<sub>3</sub>), or indirectly (via sorption, complexes, or inclusion into the crystal structure). Further, CaCO<sub>3</sub> precipitates deposited on the surface or within the pore spaces of a solid matrix create a clogging effect to reduce contaminant leachate. Experimental research on MICP has shown its promise as a bioremediation technique for mining waste. Additional research is required to evaluate the long-term feasibility and potential by-products of MICP-treated/stabilized waste.
Hamid Reza Tajdari, Ali Soleymani, Nosratolah Montajabi
et al.
Abstract This study aimed to investigate the effect of salinity and water stress on the physiological and functional characteristics of winter wheat (Triticum aestivum L.) under the foliar application of plant growth regulators (PGRs). The experiment was carried out as a split plot based on a randomized complete block design with three replications in two environments. In each environment, water stress at two irrigation levels (after 90 and 120 mm of pan evaporation) and with two EC of 1.5 and 10 dS/m in the main plots and spraying of PGRs including salicylic acid (SA), gibberellic acid (GA3), and cytokinins (CK) (purine) content with a concentration of 100 ppm and the control treatment (spraying solution with normal water) were placed in subplots. Results indicated that all treatments caused significant increases in functional and qualitative characteristics and yield of Triticum aestivum L. The saline environment and irrigation level after 120 mm of pan evaporation caused a reduction in grain yield in all traits except for seed proline, seed nitrogen content, and seed protein content. Also, the combined foliar application of GA3 + CK + SA increased yield in most traits. The highest RWC of flag leaves was observed in the foliar application of GA3 + SA (3.36 kg/ha) and then in the foliar application of GA3 + SA + CK (57.87 kg/ha). GA3 interacts with PGR spraying to balance another development under saline and non-saline conditions.
Unraveling the Role of Mn(VI) and Mn(V) Species in Contaminant Abatement by Permanganate Jie Chen,† Bo Sun,‡ Yating Zhu,† Youqiang Yang,§ Xiaohong Guan†,* †State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, P. R. China ‡Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao, Shandong, 266237, P. R. China §Shanghai Municipal Engineering Design Institute (Group) Co., Ltd., Shanghai 200092, P. R. China
مقدمه: خشکسالی تأثیرات مخربی بر محیط زیست دارد. خشکسالی در ایران به تمام نقاط کشور سرایت کرده است. هدف از این مطالعه بررسی مکانیسم های موثر مدیریت بحران خشکسالی از دیدگاه کارشناسان وزارت جهادکشاورزی استان البرز بود.
روش: تحقیق حاضر از نوع تحقیقات کاربردی و به روش توصیفی، همبستگی می باشد. جامعه آماری این تحقیق شامل 316 نفر از کارشناسان سازمان جهاد کشاورزی استان البرز بوده است. نحوه تعیین حجم نمونه براساس جدول کرجی و مورگان برابر 183 نفر محاسبه شده است و روش نمونه گیری به صورت تصادفی ساده با نسبت متناسب بوده است.آلفای محاسبه شده برای پرسشنامه تحقیق حاضر 80/0 می باشد.
یافتهها: داده های تحقیق حاکی از آن است که متغیر عوامل مدیریتی حدود 4/32 ، متغیر عوامل اقتصادی حدود 31 درصد ، متغیر عوامل آموزشی حدود 5/28 درصد ومتغیر عوامل فرهنگی- اجتماعی حدود 5/30 درصد از تغییرات متغیر وابسته مدیریت بحران خشکسالی را تبیین می نماید. نتایج حاصل از تحلیل عاملی شناسایی راهکارهای مدیریت بحران خشکسالی در زمینه کشاورزی در استان البرز نشان داد که؛ راهکارهای سیاسی - حمایتی، راهکارهای مدیریتی، راهکارهای فنی، راهکارهای قانونی، راهکارهای آموزشی و راهکارهای اقتصادی به ترتیب اولویت عواملی هستند که بیشترین سهم را در تبین راهکارهای مدیریت بحران خشکسالی در زمینه کشاورزی در استان البرز از دیدگاه کارشناسان مورد مطالعه داشته اند. این عوامل مقدار12/72 درصد از واریانس کل متغیرها را به خود اختصاص داده است.
نتیجهگیری: با توجه به نتایج حاصل از تحقیق شناسایی راهکارهای مدیریت بحران خشکسالی در زمینه کشاورزی در استان البرز می توان اظهار نمود که؛ راهکارهای سیاسی - حمایتی، راهکارهای مدیریتی، راهکارهای فنی، راهکارهای قانونی، راهکارهای آموزشی و راهکارهای اقتصادی به ترتیب اولویت عواملی هستند که بیشترین سهم را در تبین راهکارهای مدیریت بحران خشکسالی در زمینه کشاورزی در استان البرز از دیدگاه کارشناسان مورد مطالعه داشته اند. لازم است سیاستهای حمایتی مناسب برای محافظت از کشاورزان در هنگام خشکسالی به منظور کاهش آسیب پذیری آنان دنبال شود. اتخاذ سیاست های مناسب مدیریت منابع آب کشاورزی توسط مدیریت آب کشور، افزایش دانش روستائیان در ارتباط با مدیریت مصرف بهینه آب کشاورزی، توجه به دانش بومی کشاورزی به منظور مدیریت خشکسالی، بیمه محصولات کشاورزی در معرض خطر خشکسالی، همکاری با دانشگاه های موفق در زمینه مدیریت خشکسالی، استفاده از تجارب سایر کشورها در زمینه مصرف بهینه آب گردد.
Lupita D. Montoya, Lorelay M. Mendoza, Christine Prouty
et al.
Communities of color are disproportionately burdened by environmental pollution and by obstacles to influence policies that impact environmental health. Black, Hispanic, and Native American students and faculty are also largely underrepresented in environmental engineering programs in the United States. Nearly 80 participants of a workshop at the 2019 Association of Environmental Engineering and Science Professors (AEESP) Research and Education Conference developed recommendations for reversing these trends. Workshop participants identified factors for success in academia, which included adopting a broader definition for the impact of research and teaching. Participants also supported the use of community-based participatory research and classroom action research methods in engineering programs for recruiting, retaining, and supporting the transition of underrepresented students into professional and academic careers. However, institutions must also evolve to recognize the academic value of community-based work to enable faculty, especially underrepresented minority faculty, who use it effectively, to succeed in tenure promotions. Workshop discussions elucidated potential causal relationships between factors that influence the co-creation of research related to academic skills, community skills, mutual trust, and shared knowledge. Based on the discussions from this workshop, we propose a pathway for increasing diversity and community participation in the environmental engineering discipline by exposing students to community-based participatory methods, establishing action research groups for faculty, broadening the definition of research impact to improve tenure promotion experiences for minority faculty, and using a mixed methods approach to evaluate its impact.
Joel Gustavo Teleken, Jaqueline Zanovelli Nalevaiko, Paulo André Cremonez
O atual cenário energético mundial é de busca por combustíveis mais limpos e novas fontes de energia renováveis, com destaque à utilização de biomassa residual. O presente trabalho busca avaliar as características físico-químicas de briquetes produzidos a partir do bagaço da cana-de-açúcar, bagaço de mandioca e cama de aviário. Os subprodutos passaram por análises antes e após a briquetação. Foram produzidos briquetes com diferentes percentuais de mistura (M1, M2 e M3). Os briquetes produzidos apresentaram valores de eficiência energética, resistência mecânica e densidade aparente e energética coerentes com valores da literatura e de normativas internacionais. Em relação ao teor de cinzas nenhum deles se enquadra nos parâmetros europeus de fabricação de briquetes. A mistura com melhor eficiência energética foi M2, com poder calorífico de 16,41 MJ/kg e também o menor teor de cinzas, de 7,96%, e melhor relação C/H, porcentagem de hidrogênio e de carbono, sendo assim o de maior potencial energético de queima. A utilização de briquetes produzidos a partir de biomassa residual apresenta muitas vantagens, contribuindo em aspectos econômicos, sociais e ambientais.