bluuebunny/crossref_metadata_2025 huggingface dataset:
Curcumin improves atrial fibrillation susceptibility by regulating tsRNA expression in aging mouse atrium
Authors: Luo Xueshan , Liu Panyue , Ye Xingdong , He Jintao , Lai Yingyu , Lv Yidong , Wu Xiongbin , Liu Yang , Zhang Qianhuan , Yang Hui , Wei Wei , Deng Chunyu , Kuang Sujuan , Wu Shulin , Xue Yumei , Rao Fang
Published: July 2024

Age is an independent risk factor for atrial fibrillation (AF), and curcumin can delay aging related disease through reducing oxidative stress and inflammation. However, its target in aging-related AF remains unclear. Transfer RNA-derived small RNA (tsRNA) is a novel short non-coding RNA (sncRNA), and exerts a potential regulatory function in aging. This study was to explore the therapeutic targets of curcumin in atrium of aged mice by PANDORA-seq. Aged mice (18 month) were treated with curcumin (100 mg/kg). Rapid transjugular atrial pacing was performed to observe AF inducibility. SA-β-gal staining, reactive oxygen species (ROS) detection and qRT-PCR were used to assess the degree of aging and oxidative stress/inflammation levels. PANDORA-seq was performed to reveal the differentially expressed sncRNAs in the atrium of mice. The results showed that curcumin reduced the susceptibility AF of aged mice by improving aging-related atrial fibrosis. Compared to young mice (5 month) group, aged mice yielded 473 significantly altered tsRNA sequences, while 947 tsRNA sequences were significantly altered after treated with curcumin. Enrichment analysis revealed that the target genes were mainly related to DNA damage and protein modification. Compared with the 5 month group, the expression levels of mature-mt_tRNA-Val-TAC_CCA_end, mature-mt_tRNA-Glu-TTC_CCA_end, and mature-tRNA-Asp-GTC_CCA_end were up-regulated in the 18 month group, while the expression of mature-mt_tRNA-Thr-TGT_5_end was down-regulated. This trend was reversed in the 18 month + curcumin group. Increased cellular ROS levels, inflammation expression and senescence in aged mice atrium were improved by the down-regulation of mature-mt_tRNA-Val-TAC_CCA_end. In conclusion, our findings identified mature-mt_tRNA-Val-TAC_CCA_end participated in the mechanism of aging-related atrial fibrosis, providing new intervention target of aging-related AF.
Correlation between Visceral Fat with Pulse Pressure in Young Offsprings of Hypertensive and Normotensive Parents: A Cross-sectional Observational Study
Authors: Choubey Arti , Verma Vivek , Kumar Sumit
Published: July 2024

Introduction: Increased Pulse Pressure (PP) and arterial stiffness are both associated with an elevated risk of Cardiovascular Disease (CVD). Raised PP is an independent prognostic marker for CVD not only in adults but also in young normotensive subjects. Normotensive Offspring of Hypertensive Parents (OHP) are more likely to develop future hypertension. Visceral obesity, closely tied to endocrine activity, magnifies susceptibility to hypertension and CVD development in young adults. Thus, understanding the association between visceral fat and PP assumes paramount importance in young adults. Aim: To study the correlation between visceral fat and PP in young offspring of hypertensive and normotensive parents. Materials and Methods: The cross-sectional study was conducted in the Department of Physiology, Government Medical College, Datia, Madhya Pradesh, India for eight months from June 2023 to January 2024 among 140 healthy young participants aged 18-25 years. The subjects were divided into two groups: Group-1 {Offspring of Normotensive Parents (ONP)} and Group-2 offsprings of Hypertensive Parents (OHPs). Body composition parameters and visceral fat levels were measured using a calibrated Karada scan. Detailed information regarding the history of hypertension in the family, alcohol intake, etc., was collected in a pre-defined proforma. Blood pressure measurements of subjects were taken using a standard electronic sphygmomanometer. Statistical analysis of the data was conducted using Statistical Package for Social Sciences (SPSS) Version 28.0 software. For correlational analysis, Pearson correlation test was used and a p-value <0.05 considered significant. Results: The findings revealed a significant positive correlation between visceral fat levels and PP levels (p<0.05, r=0.58 and 0.57) in the two groups. Visceral fat levels were significantly higher in OHPs than in ONPs. Conclusion: Visceral fat and PP showed a correlation within the young population, irrespective of hypertensive or normotensive parents. However, visceral fat and PP levels were higher in the OHPs. This study suggests that maintaining a healthy body fat composition rather than just body weight might be pivotal for long-term hypertension prevention.
Knowledge, Attitude and Practices Regarding Marijuana usage among Medical Students: A Descriptive Cross-sectional Study
Authors: Mhetre Bhushan , Baghel Preetika , Kshirsagar Mihir , Solunke Hrishikesh , Goel Aayushi , Datar Sanaa Gore
Published: July 2024

Introduction: The increment in marijuana use across the world is concerning and needs to be addressed. There has been a cultural change regarding the perception and use of marijuana medicinally and recreationally, even among medical students. This needs to be studied to understand the outlook towards marijuana among young adults, including future doctors, to help improve their awareness of the risks and pitfalls of marijuana usage. Aim: To evaluate the knowledge, attitude, and practices regarding marijuana usage among medical students. Materials and Methods: This cross‑sectional study recruited 159 medical undergraduate students from the tertiary healthcare institute, Smt. Kashibai Navale Medical College and General Hospital, Pune, Maharashtra, India via an online, anonymised, semistructured, self-designed questionnaire that was circulated over social media. The duration of the study was from October 2023 to February 2024. The study population was grouped into first-year and final-year MBBS students to identify differences, if any, in knowledge, attitude, and practices regarding marijuana usage among students between the start and end of their MBBS training. The responses to questions were compared to establish any statistical significance. Results: Out of the total 159 participants, 106 (66.67%) were first-year MBBS students, and 53 (33.33%) were final-year MBBS students. Most students from both groups reported that marijuana was illegal in India. Both groups responded affirmatively to questions regarding their awareness of the effects of marijuana and whether it could be used as a medical therapeutic drug. The majority of students, 81 (76.42%) and 32 (60.38%), respectively in both groups, agreed with the statement that marijuana impairs concentration and movement. A total of 88 (83.02%) and 41 (77.36%) participants, respectively, were largely in favour of legalising marijuana, with a greater proportion of respondents from both groups opining that marijuana should be legalised, be it for medical therapeutic use or as a recreational drug. Conclusion: Study results showed that the majority of students from both groups responded positively to the question about the legalisation of marijuana in India. Some interesting differences were found between the two groups with respect to marijuana use and the perceptions about its positive or negative effects. It is essential to educate medical students, as future physicians, on the adverse effects and implications of marijuana use.
Population Dynamics of Whitefly and Disease Incidence of Yellow Vein Mosaic Virus Disease in Okra
Authors: Singh Samir Pratap , Singh S. K. , Awasthi L. P. , Ray Pankaj Kumar , Singh Vinod Kumar , Shukla Pavan , Singh Ashutosh , Kumar Lalbabu
Published: July 2024

Okra (Abelmoschus esculentus L.) belong to the Malvaceae family and an important vegetable crop widely cultivated in the Indian subcontinent. However, several factors influence okra crop as biotic and abiotic. Among the diseases affecting its cultivation, okra yellow vein mosaic disease (OYVM) belong to the family Geminiviridae and genus Begomovirus and transmitted by whitefly (Bemisia tabaci, Order: Hemiptera, Family: Aleyrodidae, is the one of the most destructive disease. Randomly selected five plants of each plot were observed for the population of whitefly at weekly interval starting with 20 days after sowing. First appearance of whitefly was recorded at 30th standard weekand rapid progress of whitefly population was recorded from 31th standard week to 37th and 38th standard week during both the years. The whitefly population with the minimum temperature and relative humidity showed non-significant positive correlation, whereas, maximum temperature and rainfall was non-significantly negative correlated during both the years. The whitefly population was non-significantly positive correlated with percent disease incidence of YVMV.
Genetic Differentiation of Indian Zebu Cattle (Bos tauraus) Breeds Using Random Oligonucleotide Primers (RAPD-PCR) in Amravati Region, Maharashtra, India
Authors: Tayde Nilima J. , Nandurkar Hemlata P. , Warghat Nandakishor E.
Published: July 2024

In India, insufficient characterization skills and extensive crossbreeding of cattle have led to the loss of several breeds. The purpose of this work is to find polymorphic primers for identifying Zebu cattle breeds. Random crossbreeding has resulted in genetic losses among the Gaolao, Krishna Valley, and Hallikar breeds. Genetic characterization and cryopreserving semen are critical components of conservation and breeding initiatives. The study highlights the urgent need for effective genetic characterization of Zebu cattle breeds in India, identifying 8 polymorphic and 4 monomorphic primers through RAPD-PCR. These findings are crucial for accurate breed identification, which is essential for conservation efforts and informed breeding strategies to preserve genetic diversity and prevent the decline of indigenous breeds like Gaolao, Krishna Valley, and Hallikar. Genomic DNA was isolated from whole blood using a DNA extraction kit and amplified with RAPD-PCR. A total of 12 primers were evaluated, and agarose gel electrophoresis revealed that eight (OPA-09, OPA-15, OPB-13, OPB-07, OPB- 05, OPA-13, OPA-18, and OPA-01) were polymorphic and four (OPB-06, OPA-04, OPB-03, and OPA-02) were monomorphic. Polymorphic primers demonstrated relatedness between some of the available breeds. Primers OPA-09 and OPA-15 showed a higher degree of polymorphism than primers OPB-13, OPB-07, OPB-05, OPA-13, OPA-18, and OPA-01, indicating that primers OPA-09 and OPA-15 may successfully identify various cattle breeds.
Comparative Study of Antagonistic Effect of Soil-Derived Strains of Trichoderma harzianum Against Sclerotinia sclerotium (Lib). de Bary under In vitro Conditions
Authors: Fayaz Falak , Singh Ramji , Haider Mohammad Waris
Published: July 2024

Sclerotinia sclerotiorum (Lib.) de Bary is a soil-borne plant fungal pathogen with a broad host range and infects over 400 plant species at all growth and development stages. In chickpeas,it affects both the seedlings as they tend to collapse at the soil line and in grown up plants experience stem rot and non specific wilting. Trichoderma spp. act as an effective biocontrol agent for managing myriads of plant pathogens affecting various crops at different stages of growth. The research aimed to compare the antagonistic potential of lab-maintained Trichoderma harzianum strains (SV-1, SV-2, SV3, SV-14, SV-18, and IRRI-1) with those re-isolated from soil after intervals of 30, 60 and 90 days. Its already known that pathogens if subcultured for long suffer from attenuation in their virulence, on the similar lines we intended to determine whether some degree of loss in their antagonistic potential over the same strains inoculated and re-isolated from their natural ecological niche existed or so. In a dual culture assay, re-isolated strains demonstrated superior antagonistic effects on the pathogen's mycelial growth compared to lab-maintained counterparts. Notably, re-isolated strain SV-18 exhibited a 14.83% increase in antagonistic activity compared to the mother culture, while others showed an increase ranging from 6.99% to 9.32% after 30 days. Although the difference was slightly reduced after 60 days, it underscored the potential loss in antagonistic efficacy for Trichoderma harzianum strains subjected to decade long culturing and sub-culturing. Furthermore, a significant variation was reported in the inhibition %age between the re-isolations performed statistically as F(static) 46.3426 was reported to be much larger than the critical value. These findings highlight the significance of re-isolated strains outperforming in inhibiting the pathogen, emphasizing the importance of biocontrol agents functioning optimally in their natural ecological niches.
Characterisation of Soil Properties of CRC-2 and CRC-3 at ITM University, under Gwalior Region, M.P, India
Authors: Meitei Aheibam Lamjingba , Gautam Sandip Kumar
Published: July 2024

The present “Characterisation of soil properties of CRC-2 and CRC-3 at ITM University, under Gwalior region, M.P” was carried out during the year 2024 in the department of soil science and agricultural chemistry, school of agriculture, ITM University, Gwalior. I collect the soil by traversing representative areas of CRC-2 and CRC-3, the soil survey under the high intensity. For the CRC-2 the total soil is 36 and for the CRC-3 is 66 and the soil is collected surface (0-15cm) and sub-surface (15-30cm). The collected soil is preparing for the various analysed of soil physical parameters like bulk density, mechanical analysis, porosity, particle density, moisture content, osmotic pressure and total dissolved soil. The bulk density of surface for the CRC-2 is range from 1.32 to 1.38 mg m-3 and the sub-surface is 1.36 to 1.41 mg m-3 while for the CRC-3 surface value of bulk density is ranged from 1.32 to 1.39 mg m-3 and the sub-surface is ranged from 1.35 to 1.44 mg m-3. The mechanical analysis of surface for the CRC-2 is ranged from 59.7 to 61.0% and the sub-surface is ranged from 55.7 to 57.3%, for the CRC-3, it ranged from the 59.7 to 61.5% for surface and the sub-surface is ranged from 55.7 to 57.6%. The porosity of CRC-2, it ranged from 49.5 to 49.8% in surface and 50.0 to 50.7% in the sub-surface, where for the CRC-3 it ranged from 49.5 to 50.7% in the surface and 49.6 to 50.9% in the sub-surface. The silt% in the CRC2 is ranged from the 18.5 to 20.2% in surface and 16.7 to 18.5% in sub-surface while, CRC3 the silt% are ranged from18.53 to 20.30 % in surface and 16.6 to 19.4% in sub-surface The clay (%) of the CRC 2 are ranged from the 19.6 to 21.8% in surface and 21.4 to 23.4% in sub-surface while for the CRC 3 are ranged from the 19.6 to 21.8% in surface and sub-surface is 21.3 to 23.5%. Particle density for the CRC-2 ranged from 2.33 to 2.59 g cm-3 in the surface and 2.61 to 2.80 g cm-3 in sub-surface, for the CRC-3 it ranged from 2.30 to 2.58 g cm-3 in the surface and 2.59 to 2.90 g cm-3 in sub-surface. The moisture content of CRC-2 is ranged from 12.33 to 12.77% in the depth of 0-15cm and 12.85 to 13.23% in the depth 15-30cm. And the CRC-3 the value is ranged from 12.35 to 12.87% in the depth of 0-15cm and 12.86 to 13.35% in the depth of 15-30cm. The osmotic pressure for the CRC-2 is ranged from 0.175 to 0.183 N m-2 in the depth of 0-15cm and 0.182 to 0.187 N m-2 in the depth of 15-30cm where for the CRC-3 it ranged from 0.174 to 0.184 N m-2 in the depth of 0-15cm and 0.182 to 0.190 N m-2 in the depth of 15-30cm. Total dissolved soil for the CRC-2 ranged from 493.0 to 497.1% in the depth of 0-15cm and 497.7 to 503.9% in the depth of 15-30cm and for the CRC-3 it ranged from 494.1 to 498.8% in the depth of 0-15cm and 497.2 to 503.5% in the depth of 15-30cm.
The Role of Genome Editing Technologies in Sustainable Agriculture
Authors: Waghmode Prajyot , Pitha Chetariya Chana , Banka Vaishnavi
Published: July 2024

Genome editing technologies have emerged as powerful tools for making precise and targeted modifications in the DNA of living organisms, offering unprecedented opportunities to revolutionize agriculture amidst global challenges such as population growth, climate change, and diminishing resources. This review provides an overview of genome editing principles, its comparison with traditional breeding and genetic engineering methods, and the regulatory landscape governing its application. The CRISPR/Cas9 system, in particular, has revolutionized genome editing due to its efficiency, affordability, and versatility. By harnessing this system, researchers can induce specific modifications in plant genomes, enhancing traits such as yield, quality, and resilience to biotic and abiotic stresses. The review highlights recent advancements in CRISPR/Cas9 technology, including its adaptation for base editing and prime editing, which allow for precise nucleotide substitutions and broaden the scope of genetic modifications possible in crops. Addressing the regulatory environment surrounding genome-edited crops, the paper discusses existing regulations, international agreements, and ethical considerations. It emphasizes the need for science-informed regulations that balance innovation with transparency and public safety, crucial for fostering societal acceptance and facilitating global trade in genetically modified agricultural products. Furthermore, the review explores case studies and trends in genome editing applications across different crop species, illustrating how these technologies are being employed to address challenges in agriculture. From improving disease resistance to optimizing nutrient content and environmental adaptation, genome editing offers a pathway towards sustainable crop improvement. Looking forward, the review outlines future prospects and challenges in the field, including potential limitations such as off-target effects and the need for enhanced precision in editing techniques. It underscores the importance of integrating genome editing with conventional breeding methods to optimize agricultural productivity and resilience in the face of evolving environmental pressures. Genome editing holds immense promise for enhancing global food security and sustainability. By elucidating the current landscape of genome editing technologies and their applications in agriculture, this review aims to provide a comprehensive resource for policymakers, regulators, researchers, and the public, facilitating informed decision-making and supporting the responsible deployment of these transformative technologies in agriculture.
Plant Growth Regulators in Abiotic Stress Resilience of Plants: A Review
Authors: Madhumitha M. , Sundaram V.
Published: July 2024

In recent decades, the global demand for vegetables has surged alongside population growth. However, biotic and abiotic stresses increasingly hinder seed germination, growth and yields. Plant growth regulators (PGRs) acting as chemical messengers are crucial in regulating plant development and responses to environmental stresses. Key phytohormones like abscisic acid, ethylene, salicylic acid and jasmonic acid play pivotal role in stress responses of vegetable crops. These hormones enable plants to sense and adapt to adverse conditions such as drought, salinity and extremities of temperatures. Through enzyme activation and hormone synthesis, plants enhance their resilience to stressors.  The growth regulators initiate/activate a cascade event either on their own or by evolving a cross - talk within them that final recruits various transcription factors those in turn activate or suppress a variety of genes. The vital role of PGRs in mitigating stress impacts on vegetable crops, highlighting their potential in agricultural sustainability in future.
Modelling and Optimization of a Brewery Plant from Starch Sources using Aspen Plus
Authors: Okon John Effiong , Oboh Innocent Oseribho
Published: July 2024

The brewing industry faces challenges with the use of malted barley as the primary starch source in Nigeria including quality control and standards, local production and demand, market competition, and price. The challenges of developing new product designs using pilot plants include inherent drawbacks and significant time constraints.
This research explores the potential of sorghum as a valuable addition to barley in the brewing industry, especially in semi-arid regions like Africa. This study developed and optimised a model simulated using Aspen Plus for the brewing process, incorporating both malted barley and raw sorghum. Process parameters from a Brewery Plant formed the basis for the model to simulate the entire process from grain to fermented beverage. 1417.5Kg of raw sorghum grist was mashed in the mash copper vessel with 4800Kg of process water at 50℃ to observe protein rest and heated up to 93℃. The mash is cooled down to 75℃ via the mash cooler. At heating to 93℃ of the mash copper, 937.2kg of malted barley grist was mashed in the mash tun vessel with 3500Kg of process water at 50℃ to obverse protein rest. The cooled mash in the mash copper was transferred to the mash tun to achieve saccharification at 66℃ yielding 2460.658 kg/hr of wort after wort separation using a mash filter in the wort kettle. The wort was boiled to 100oC for concentration and sterilization. The boiled wort is pitched with brewer’s yeast (Saccharomyces cerevisiae) after chilling down to 9oC via a plate heat exchanger to commence fermentation. 1321.781 kg/hr of ethanol is produced in the fermentation storage tank during fermentation. Optimisation efforts focused on varying the barley to sorghum ratio, optimizing barley feed resulted in statistically significant improvements in ethanol yield (p<0.0001). The model's accuracy was confirmed through Box-behnken design and ANOVA, demonstrating strong agreement between actual and simulated ethanol yields. Additionally, pinch analysis facilitated heat exchanger optimization, enhancing energy efficiency and sustainability during the brewing process. Heat gained via the water side of the plate heat exchanger during wort cooling was charged into the system for sparging process amounting to energy cost saving of 0.34%. The economic analysis underscored the financial viability of the brewing process, with a total capital cost of $1,133,600.00 and annual operating expenses of $16,831,800.00. Raw material costs totaled $14,738,400.00 annually, while product sales generated $251,082,000.00 per year. Moreover, energy savings were achieved, with low pressure (LP) steam utilization saving $91 per year and refrigerant use contributing $46 annually. The desired rate of return for the project is set at 20% per year, with a payback period of 1.5 years. The findings from this study will contribute to the growing body of knowledge in the field of brewing process simulation and modeling and have practical implications for the brewing industry.
Development Status and Outlook of Hydrogen Internal Combustion Engine
Authors: Liu Mengfei
Published: July 2024

Hydrogen energy is the best energy carrier to achieve carbon peak and carbon neutrality, with high energy and pollution-free characteristics. Hydrogen internal combustion engine is one of the important forms of hydrogen energy utilization, which has significant advantages of high efficiency, high reliability, low cost and low emissions. In this paper, the characteristics of hydrogen internal combustion engines and hydrogen fuel cells are compared, and the industrialization prospects of hydrogen energy utilization in the future are analyzed. Focusing on the technical system of hydrogen internal combustion engine, the technical problems and technical progress of hydrogen storage, combustion and NOx emission of hydrogen internal combustion engine are comprehensively analyzed.
Best Management Practices Followed by Agri-Incubatees of ANGRAU Agribusiness Incubator in Tirupati, India
Authors: Reddy P. Hanumanth , Lalitha A. , Reddy P. Bala Hussain , Purnima K. S. , Vijayreddy Dumpapenchala
Published: July 2024

The ANGRAU Agribusiness Incubator was purposively selected for the study conducted in the year 2023 because it has a specific focus on nurturing agri-startups that are working towards improving the farming communities in the state of Andhra Pradesh. Ten successful incubatees trained at the ANGRAU agribusiness incubator were purposively selected for the study, based on category, product, service, R&D and achievements. The findings demonstrated that best management practices such as practices such as offering innovative products/services, leveraging technology and automation, staying adaptable to changing market trends, prioritizing customer satisfaction, maintaining transparency and ethical practices and implementing effective waste management and recycling received the highest mean score of 3, ranking I. Following closely with a mean score of 2.9 and ranking II were strategies including vision and mission prepared, actively managing risks and developing contingency plans, consistently evaluate and improve product quality and ensuring compliance with government laws and regulations. Practices like monitoring and evaluating financial performance, integrating sustainable practices in the supply chain, conducting feasibility surveys/market research, setting clear and measurable goals, giving employment to at least three persons, actively building a network of stakeholders and forming strategic partnerships, implementing effective marketing strategies, focusing on brand identity and positive image and regularly optimizing operational costs scored between 2.8 to 2.4, placing them in ranks between Ⅲ & Ⅶ. However, practices concerning leveraging digital marketing strategies, having a detailed project report and income flow statement, developing a comprehensive business plan, seeking partnerships and collaborations for innovation, establishing relationships with financial institutions for funding and creating assets for the agribusiness with profits ranked lower, indicating disagreement among agri-incubatees, with scores 2.3 to 1.9 placing them in ranks between Ⅷ  and Ⅸ. Perception of the incubatees towards best management practices inferred that nearly one-third (30.00%) of the agri-incubatees rated their best management practices as low, while half of the incubatees (50.00%) considered them moderate, and only one-fifth (20.00 %) of the agri-incubatees rated their practices as high.
Overview of Electrophysiological Techniques
Authors: Wickenden Alan D.
Published: March 2014

This unit provides an overview of the principal electrophysiological techniques commonly used for the study of ionic currents and the ion channels that mediate them. These techniques include electroencephalograms (EEGs), electrocardiograms (ECGs), single‐ and multiunit extracellular recording, multielectrode arrays, transepithelial recording, impedance measurements, and current‐clamp, voltage‐clamp, patch‐clamp, and lipid bilayer recording. The unit also discusses recent advances in high‐throughput, automated electrophysiological techniques for drug discovery and the use of stem cells as a tissue source. Curr. Protoc. Pharmacol. 64:11.1.1‐11.1.17. © 2014 by John Wiley & Sons, Inc.
River‐aquifer interactions in a semiarid environment investigated using point and reach measurements
Authors: McCallum Andrew M. , Andersen Martin S. , Rau Gabriel C. , Larsen Joshua R. , Acworth R. Ian
Published: March 2014

A critical hydrological process is the interaction between rivers and aquifers. However, accurately determining this interaction from one method alone is difficult. At a point, the water exchange in the riverbed can be determined using temperature variations over depth. Over the river reach, differential gauging can be used to determine averaged losses or gains. This study combines these two methods and applies them to a 34 km reach of a semiarid river in eastern Australia under highly transient conditions. It is found that high and low river flows translate into high and low riverbed Darcy fluxes, and that these are strongly losing during high flows, and only slightly losing or gaining for low flows. The spatial variability in riverbed Darcy fluxes may be explained by riverbed heterogeneity, with higher variability at greater spatial scales. Although the river‐aquifer gradient is the main driver of riverbed Darcy flux at high flows, considerable uncertainty in both the flux magnitude and direction estimates were found during low flows. The reach‐scale results demonstrate that high‐flow events account for 64% of the reach loss (or 43% if overbank events are excluded) despite occurring only 11% of the time. By examining the relationship between total flow volume, river stage and duration for in‐channel flows, we find the loss ratio (flow loss/total flow) can be greater for smaller flows than larger flows with similar duration. Implications of the study for the modeling and management of connected water resources are also discussed.
Soil organic carbon sequestration in upland soils of northern China under variable fertilizer management and climate change scenarios
Authors: Jiang Guiying , Xu Minggang , He Xinhua , Zhang Wenju , Huang Shaomin , Yang Xueyun , Liu Hua , Peng Chang , Shirato Yasuhito , Iizumi Toshichika , Wang Jinzhou , Murphy Daniel V.
Published: March 2014

We determined the historical change in soil organic carbon (SOC) stocks from long‐term field trials that represent major soil types and climatic conditions of northern China. Soil carbon and general circulation models were validated using these field trial data sets. We then applied these models to predict future change in SOC stocks to 2100 using two net primary production (NPP) scenarios (i.e., current NPP or 1% year−1NPP increase). The conversion rate of plant residues to SOC was higher in single‐cropping sites than in double‐cropping sites. The prediction of future SOC sequestration potential indicated that these soils will be a net source of carbon dioxide (CO2) under no fertilizer inputs. Even when inorganic nutrients were applied, the additional carbon input from increased plant residues could not meet the depletion of SOC in parts of northern China. Manure or straw application could however improve the SOC sequestration potential at all sites. The SOC sequestration potential in northern China was estimated to be −4.3 to 18.2 t C ha−1by 2100. The effect of projected climate change on the annual rate of SOC change did not differ significantly between climate scenarios. The average annual rate of SOC change under current and increased NPP scenarios (at 850 ppm CO2) was approximately 0.136 t C ha−1yr−1in northern China. These findings highlight the need to maintain, and where possible increase, organic carbon inputs into these farming systems which are rapidly becoming inorganic fertilizer intensive.
Ensemble prediction and intercomparison analysis of GRACE time‐variable gravity field models
Authors: Sakumura C. , Bettadpur S. , Bruinsma S.
Published: March 2014

Precise measurements of the Earth's time‐varying gravitational field from the NASA/Deutsches Zentrum für Luft‐ und Raumfahrt Gravity Recovery and Climate Experiment (GRACE) mission allow unprecedented tracking of the transport of mass across and underneath the surface of the Earth and give insight into secular, seasonal, and subseasonal variations in the global water supply. Several groups produce these estimates, and while the various gravity fields are similar, differences in processing strategies and tuning parameters result in solutions with regionally specific variations and error patterns. This study examined the spatial, temporal, and spectral variations between the different gravity field products and developed an ensemble gravity field solution from the products of four such analysis centers. The solutions were found to lie within a certain analysis scatter regardless of the local relative water height variation, and the ensemble model is clearly seen to reduce the noise in the gravity field solutions within the available scatter of the solutions.
Evaluation of boundary layer cloud parameterizations in the ECHAM5 general circulation model using CALIPSO and CloudSat satellite data
Authors: Nam Christine C. W. , Quaas Johannes , Neggers Roel , Siegenthaler‐Le Drian Colombe , Isotta Francesco
Published: March 2014

Three different boundary layer cloud models are incorporated into the ECHAM5 general circulation model (GCM) and compared to CloudSat and CALIPSO satellite observations. The first boundary layer model builds upon the standard Tiedtke (1989) parameterization for shallow convection with an adapted convective trigger; the second is a bulk parameterization of the effects of transient shallow cumulus clouds; and lastly the Dual Mass Flux (DMF) scheme adjusted to better represent shallow convection. The three schemes improved (Sub)Tropical oceanic low‐level cloud cover, however, the fraction of low‐level cloud cover remains underestimated compared to CALIPSO observations. The representation of precipitation was improved by all schemes as they reduced the frequency of light intensity events <0.01 mm d−1, which were found to dominate the radar reflectivity histograms as well as be the greatest source of differences between ECHAM5 and CloudSat radar reflectivity histograms. For both lidar and radar diagnostics, the differences amongst the schemes are smaller than the differences compared to observations. While the DMF approach remains experimental, as its top‐of‐atmosphere radiative balance has not been retuned, it shows the most promise in producing nonprecipitating boundary layer clouds. With its internally consistent boundary layer scheme that uses the same bimodal joint distribution with a diffusive and an updraft component for clouds and turbulent transport, the ECHAM5_DMF produces the most realistic boundary layer depth as indicated by the cloud field. In addition, it reduced the frequency of large‐scale precipitation intensities of <0.01 mm d−1 the greatest.
Angular and RMS delay spread modeling in view of THz indoor communication systems
Authors: Priebe Sebastian , Jacob Martin , Kürner Thomas
Published: March 2014

Future wireless communication systems will most likely be operated at carrier frequencies above 300 GHz, where the indoor radio channel behaves entirely differently compared to legacy radio communication frequencies. Being highly relevant for system performance evaluations and channel modeling, the spatial as well as the temporal dispersions are studied for a representative office wireless LAN scenario in this paper. Ray tracing serves as the means for the accurate simulation of the THz radio wave propagation. Simple stochastic models are derived to approximate and reproduce the distance‐dependent behavior of the angular spread as well as of the RMS delay spread. Based on the results, the maximum symbol rates achievable without any intersymbol interference are quantified and can be shown to reach up to several 100 GSymbols/s provided that highly directive antennas are used.
Assessing groundwater policy with coupled economic‐groundwater hydrologic modeling
Authors: Mulligan Kevin B. , Brown Casey , Yang Yi‐Chen E. , Ahlfeld David P.
Published: March 2014

This study explores groundwater management policies and the effect of modeling assumptions on the projected performance of those policies. The study compares an optimal economic allocation for groundwater use subject to streamflow constraints, achieved by a central planner with perfect foresight, with a uniform tax on groundwater use and a uniform quota on groundwater use. The policies are compared with two modeling approaches, the Optimal Control Model (OCM) and the Multi‐Agent System Simulation (MASS). The economic decision models are coupled with a physically based representation of the aquifer using a calibrated MODFLOW groundwater model. The results indicate that uniformly applied policies perform poorly when simulated with more realistic, heterogeneous, myopic, and self‐interested agents. In particular, the effects of the physical heterogeneity of the basin and the agents undercut the perceived benefits of policy instruments assessed with simple, single‐cell groundwater modeling. This study demonstrates the results of coupling realistic hydrogeology and human behavior models to assess groundwater management policies. The Republican River Basin, which overlies a portion of the Ogallala aquifer in the High Plains of the United States, is used as a case study for this analysis.
LiDAR‐derived snowpack data sets from mixed conifer forests across the Western United States
Authors: Harpold A. A. , Guo Q. , Molotch N. , Brooks P. D. , Bales R. , Fernandez‐Diaz J. C. , Musselman K. N. , Swetnam T. L. , Kirchner P. , Meadows M. W. , Flanagan J. , Lucas R.
Published: March 2014

Airborne‐based Light Detection and Ranging (LiDAR) offers the potential to measure snow depth and vegetation structure at high spatial resolution over large extents and thereby increase our ability to quantify snow water resources. Here we present airborne LiDAR data products at four Critical Zone Observatories (CZO) in the Western United States: Jemez River Basin, NM, Boulder Creek Watershed, CO, Kings River Experimental Watershed, CA, and Wolverton Basin, CA. We make publicly available snow depth data products (1 m2 resolution) derived from LiDAR with an estimated accuracy of <30 cm compared to limited in situ snow depth observations.
Characterization of groundwater and surface water mixing in a semiconfined karst aquifer using time‐lapse electrical resistivity tomography
Authors: Meyerhoff Steven B. , Maxwell Reed M. , Revil André , Martin Jonathan B. , Karaoulis Marios , Graham Wendy D.
Published: March 2014

Groundwater flow in karst includes exchange of water between large fractures, conduits, and the surrounding porous matrix, which impacts both water quality and quantity. Electrical resistivity tomography combined with end‐member mixing analysis (EMMA) and numerical flow and transport modeling was used to study mixing of karst conduit and matrix waters to understand spatial and temporal patterns of mixing during high flow and base flow conditions. To our knowledge, this is the first time EMMA and synthetic geophysical simulations have been combined. Here we interpret an 8 week time‐lapse electrical resistivity data set to assess groundwater‐surface mixing. We simulate flow between the karst conduits and the porous matrix to determine fractions of water recharged to conduits that has mixed with groundwater stored in the pore space of the matrix using a flow and transport model in a synthetic time‐lapse resistivity inversion. Comparing the field and synthetic inversions, our results enable us to estimate exchange dynamics, spatial mixing, and flow conditions. Results showed that mixing occurred at a volumetric flux of 56 m3/d with a dispersivity around 1.69 m during the geophysical experiment. For these conditions, it was determined that conduit water composition ranged from 75% groundwater during base flow conditions to less than 50% groundwater in high flow conditions. Though subject to some uncertainties, the time‐lapse inversion process provides a means to predict changing hydrologic conditions, leading to mixing of surface water and ground water and thus changes to water quantity and quality, as well as potential for water‐rock reactions, in a semiconfined, sink‐rise system.
Carbon storage in mountainous headwater streams: The role of old‐growth forest and logjams
Authors: Beckman Natalie D. , Wohl Ellen
Published: March 2014

We measured wood piece characteristics and particulate organic matter (POM) in stored sediments in 30 channel‐spanning logjams along headwater streams in the Colorado Front Range, USA. Logjams are on streams flowing through old‐growth (>200 years), disturbed (<200 years, natural disturbance), or altered (<200 years, logged) subalpine conifer forest. We examined how channel‐spanning logjams influence riverine carbon storage (measured as the total volatile carbon fraction of stored sediment and instream wood). Details of carbon storage associated with logjams reflect age and disturbance history of the adjacent riparian forest. A majority of the carbon within jams is stored as wood. Wood volume is significantly larger in old‐growth and disturbed reaches than in altered reaches. Carbon storage also differs in relation to forest characteristics. Sediment from old‐growth streams has significantly higher carbon content than altered streams. Volume of carbon stored in jam sediment correlates with jam wood volume in old‐growth and disturbed forests, but not in altered forests. Forest stand age and wood volume within a jam explain 43% of the variation of carbon stored in jam sediment. First‐order estimates of the amount of carbon stored within a stream reach show an order of magnitude difference between disturbed and altered reaches. Our first‐order estimates of reach‐scale riverine carbon storage suggest that the carbon per hectare stored in streams is on the same order of magnitude as the carbon stored as dead biomass in terrestrial subalpine forests of the region. Of particular importance, old‐growth forest correlates with more carbon storage in rivers.
A statistical approach to estimating evapotranspiration from diurnal groundwater level fluctuations
Authors: Wang Ping , Pozdniakov Sergey P.
Published: March 2014

Over the last few decades, automatic sensors that record groundwater levels at high‐frequency intervals have become widely used in groundwater monitoring practice. These sensors provide large amounts of data regarding diurnal groundwater fluctuations, which can be treated as stochastic periodic time series. In this study, a simple relationship between the average standard deviation of diurnal groundwater level fluctuations and the daily evapotranspiration over relatively short periods (days or weeks) was developed for estimating groundwater consumption by phreatophytes in arid/semiarid areas. Our approach allows estimating groundwater evapotranspiration (
) using stable statistical characteristics of diurnal groundwater fluctuations, and it is useful for analyzing large amounts of data obtained from digital groundwater level monitoring sensors. A comparison of the
results from a synthetic set of groundwater level fluctuations with predefined values shows that this technique behaves consistently and is robust. A numerical analysis of one‐dimensional saturated‐unsaturated water flow to a root system using Richards' equation indicates that this method provides a reliable estimate of
when the basic assumptions of the White method are met. The method was also applied to two phreatophyte‐dominated riparian sites in New Mexico to demonstrate its usefulness, which provides better results than the commonly used White method.
The Size Dependence of Hydrogen Mobility and Sorption Kinetics for Carbon‐Supported MgH2 Particles
Authors: Au Yuen S. , Obbink Margo Klein , Srinivasan Subramanian , Magusin Pieter C. M. M. , de Jong Krijn P. , de Jongh Petra E.
Published: March 2014

MgH2 is a promising material for reversible solid‐state hydrogen storage. It is known that particle size can have a strong impact on hydrogen dynamics and sorption characteristics, but more detailed insight has been hampered by the great challenge to prepare small and well‐defined particles and study their hydrogen storage properties upon cycling. The preparation of MgH2 nanoparticles supported on high surface area carbon aerogels with pore sizes varying from 6–20 nm is reported. Two distinctly different MgH2 particle populations are observed: X‐ray diffraction invisible nanoparticles with sizes below 20 nm, and larger, crystalline, MgH2 particles. They release hydrogen at temperatures 140 °C lower than bulk MgH2. The size‐dependent hydrogen kinetics is for the first time corroborated by intrinsic hydrogen dynamics data obtained by solid state 1H NMR. Fast cycling is possible (80% of the capacity absorbed within 15 min at 18 bar and 300 °C), without a change in the hydrogen sorption properties, showing that the growth of the nanoparticles is effectively prevented by the carbon support. A clear correlation is found between the hydrogen desorption temperature and the size of the MgH2 nanoparticles. This illustrates the potential of the use of supported nanoparticles for fast, reversible, and stable hydrogen cycling.
Heteroatom Substituted Organic/Polymeric Semiconductors and their Applications in Field‐Effect Transistors
Authors: Zhang Weifeng , Liu Yunqi , Yu Gui
Published: March 2014

Organic/polymeric semiconductors are mainly composed of aromatic systems including phenyl, vinyl, alkynyl, thienyl, and other isoelectric groups, which are constructed of carbon, hydrogen, and so‐called ‘hereroatoms’ including chalcogen, nitrogen, and halogen atoms etc. The introduction of heteroatoms could yield different electronic properties by influencing the molecular geometry, the HOMO and LUMO energy levels, intermolecular interactions and so on. In this Research News article, we provide a brief review of the effect of heteroatoms and recent developments in heteroatom substituted organic/polymeric semiconductors, focusing especially on their application in field‐effect transistors.
Click‐Chemistry Based Multi‐Component Microarrays by Quill‐Like Pens
Authors: Hirtz Michael , Greiner Alexandra M. , Landmann Tanja , Bastmeyer Martin , Fuchs Harald
Published: March 2014

We demonstrate the generation of multi‐component spot microarrays by blotting different ink solutions via quill‐like pens. The obtained arrays are immobilized by click‐chemistry in form of the copper(I)‐catalyzed azide‐alkyne cycloaddition and remain stable against washing and immersion in aqueous solution. The average spot radius ranges from 10 to 20 μm and is about an order of magnitude smaller than in currently commercially applied arraying techniques, effectively bridging the gap to high resolution methods as dip‐pen nanolithography and polymer pen lithography. The use of the quill‐like‐pen‐generated spot microarrays as binding assay is demonstrated by capturing of streptavidin from solution and by bioactive sandwich structures from neutravidin and biotin‐labeled fibronectin. Thus, our multi‐component spot microarrays have ideal dimensions and biochemical properties to accommodate (single) cells. Additionally, the building up of the cell‐recruiting protein sandwich structure on top of the basic spot microarray allows for the highly selective adhesion of fibroblasts. This results then in ordered (single) cell arrays, demonstrating the bio‐compatibility and high throughput of this multi‐component spot microarray platform.
MaxPHOS Ligand: PH/NH Tautomerism and Rhodium‐ Catalyzed Asymmetric Hydrogenations
Authors: Cristóbal‐Lecina Edgar , Etayo Pablo , Doran Séan , Revés Marc , Martín‐Gago Pablo , Grabulosa Arnald , Costantino Andrea R. , Vidal‐Ferran Anton , Riera Antoni , Verdaguer Xavier
Published: March 2014

MaxPHOS is an active and robust P‐stereogenic ligand for asymmetric catalysis. The presence of an NH bridge between the two phosphine moieties allows the NH/PH tautomerism to take place. The neutral ligand, in which the NH form predominates, is an air‐sensitive compound. However, protonation of MaxPHOS leads to the stable PH form of the ligand, in which the overall positive charge is distributed on both P centers. This protonation turns the MaxPHOS⋅HBF4 salt 3 into an air‐stable compound both in the solid state and in solution. The salt 3 is also a convenient precursor for the preparation of rhodium(I) complexes by direct ligand exchange with the complex [Rh(acac)(cod)]. Finally, the corresponding rhodium(I)‐MaxPHOS complex was tested in the asymmetric hydrogenation of a wide range of substrates. The complex proved to be a highly selective and robust system in these reactions.

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