bluuebunny/crossref_metadata_2025 huggingface dataset:
Aminergic and peptidergic modulation of Insulin-Producing Cells in Drosophila
Authors: Held Martina , Bisen Rituja S , Zandawala Meet , Chockley Alexander S , Balles Isabella S , Hilpert Selina , Liessem Sander , Cascino-Milani Federico , Ache Jan M
Published: September 2024

Insulin plays a critical role in maintaining metabolic homeostasis. Since metabolic demands are highly dynamic, insulin release needs to be constantly adjusted. These adjustments are mediated by different pathways, most prominently the blood glucose level, but also by feedforward signals from motor circuits and different neuromodulatory systems. Here, we analyze how neuromodulatory inputs control the activity of the main source of insulin in
Drosophila –
a population of Insulin-Producing Cells (IPCs) located in the brain. IPCs are functionally analogous to mammalian pancreatic beta cells, but their location makes them accessible for
in vivo
recordings in intact animals. We characterized functional inputs to IPCs using single-nucleus RNA sequencing analysis, anatomical receptor expression mapping, connectomics, and an optogenetics-based ‘intrinsic pharmacology’ approach. Our results show that the IPC population expresses a variety of receptors for neuromodulators and classical neurotransmitters. Interestingly, IPCs exhibit heterogeneous receptor profiles, suggesting that the IPC population can be modulated differentially. This is supported by electrophysiological recordings from IPCs, which we performed while activating different populations of modulatory neurons. Our analysis revealed that some modulatory inputs have heterogeneous effects on the IPC activity, such that they inhibit one subset of IPCs, while exciting another. Monitoring calcium activity across the IPC population uncovered that these heterogeneous responses occur simultaneously. Certain neuromodulatory populations shifted the IPC population activity towards an excited state, while others shifted it towards inhibition. Taken together, we provide a comprehensive, multi-level analysis of neuromodulation in the insulinergic system of
Drosophila
.
Risk Factors and Prevention of Stomach Cancer, Excluding Helicobacter pylori
Authors: Lee Seung-Woo
Published: September 2024

Gastric cancer is a significant health problem owing to its high incidence and mortality rate. The risk factors for gastric cancer include both uncontrollable (e.g., age, sex, and genetic predisposition) and controllable factors (e.g., Helicobacter pylori infection, smoking, alcohol consumption, obesity, and high-salt diets). Although treatment of H. pylori infections has been implemented as a primary preventive measure, the risk of gastric cancer may persist, highlighting the need for additional preventive measures. This review discusses various risks and protective factors associated with gastric cancer, studies conducted on these factors, and chemoprevention. Smoking is a risk factor for this disease; thus, is not recommended and current smokers are encouraged to quit because cessation can reduce the risk of gastric cancer. Excessive alcohol intake has been reported to increase the risk of gastric cancer as has the consumption of high-salt foods that can damage the gastric mucosa. Additionally, increasing the intake of fruits and vegetables, known for their protective effects against gastric cancer, can aid in its prevention. Studies on chemopreventive agents, including nonsteroidal anti-inflammatory drugs (e.g., aspirin), statins, and metformin, have been reported; however, evidence of their effectiveness remains insufficient to recommend these agents as preventive treatments. Additional well-planned studies on preventive medications and dietary approaches are necessary.
Sex/Gender Differences in Esophageal Motility Disorders
Authors: Lee Ju Yup
Published: September 2024

Esophageal motility disorders are relatively rare and are attributed to an imbalance between the excitatory and inhibitory nerves that innervate the esophagus. These disorders include achalasia, distal esophageal spasms, and jackhammer esophagus. The prevalence of achalasia is equal in men and women; however, lower esophageal hypermotility disorders are slightly more common in women. Women with achalasia experience chest pain more frequently, whereas men tend to have high lower esophageal sphincter pressure. Additionally, women with achalasia respond better to pneumatic balloon dilatation than men. However, research on sex and gender differences in the outcomes of peroral endoscopic myotomy remains insufficient. Future studies should investigate the differences in outcomes, complications, and long-term effects to ensure optimal treatment in men and women with esophageal motility disorders. This research will be useful to develop sex-tailored treatments for esophageal motility disorders.
Top-k sentiment analysis over spatio-temporal data
Authors: Almaslukh Abdulaziz , Almaalwy Aisha , Allheeib Nasser , Alajaji Abdulaziz , Almukaynizi Mohammed , Alabdulkarim Yazeed
Published: September 2024

In recent years, social media has become much more popular to use to express people’s feelings in different forms. Social media such as X (i.e., Twitter) provides a huge amount of data to be analyzed by using sentiment analysis tools to examine the sentiment of people in an understandable way. Many works study sentiment analysis by taking in consideration the spatial and temporal dimensions to provide the most precise analysis of these data and to better understand people’s opinions. But there is a need to facilitate and speed up the searching process to allow the user to find the sentiment analysis of recent top-k tweets in a specified location including the temporal aspect. This work comes with the aim of providing a general framework of data indexing and search query to simplify the search process and to get the results in an efficient way. The proposed query extends the fundamental spatial distance query, commonly used in spatial-temporal data analysis. This query, coupled with sentiment analysis, operates on an indexed dataset, classifying temporal data as positive, negative, or neutral. The proposed query demonstrates over a tenfold improvement in query time compared to the baseline index with various parameters such as top-k, query distance, and the number of query keywords.
Beyond labs: unveiling dynamics of dental students’ transition from pre-clinical to clinical training in a Saudi dental school
Authors: Khattak Osama , Ganji Kiran Kumar , Iqbal Azhar , Altassan Mosa , Khan Farida Habib , Anis Rabia
Published: September 2024

Objective

To assess the factors affecting the transition of dental students from pre-clinical to clinical courses in an outcome-based curriculum.

Methods

This cross-sectional study surveyed dental students in the third and fourth academic years of the Bachelor of Dental and Oral Surgery (BDS) program at the College of Dentistry, Jouf University. Ethically approved and powered by the G Power software, the study employed a modified questionnaire validated through a pilot test to assess five domains. Likert scale responses were analyzed using SPSS v.25, revealing insights into clinical workload, patient interaction, and learning experiences. Multiple regression analysis was used to assess the impact of clinical skill application, workload, transition to clinics, and patient interaction on learning experience as well as CGPA. The Mann-Whitney U test compared the ranks of two independent samples, making it less sensitive to outliers and more suitable for data with non-normal distributions.

Results

In this study, the response rate of the participants was 70%. A total of 44 dental students in their third and fourth years of the program completed the survey. The multiple regression analysis showed that the predictors collectively explained 36.1% of the variance in the learning experience (Adjusted R2 = 0.361). “Transition to Clinics” had a significant positive effect on learning experience (β = 0.292, p = 0.012), “Workload” (β = −0.203, p = 0.393) and “Patient Interaction” (β = 0.443, p = 0.168) were not significant predictors. The Mann-Whitney U test revealed no significant gender differences in transition to clinics, workload, patient interaction, application of clinical skills, and learning experience (U = 33.09 to −40.33, p > 0.05), but a significant difference in transition to clinics between third- and fourth-year students (U = 31.56 to −43.24, p < 0.05).

Conclusion

The results of this study demonstrate that the transition to clinical training can be intricate, and that multiple elements have an impact on this process. It is crucial to have support systems that facilitate the transition into the clinical learning environment.
Profile Characteristics of Fertilizer Dealers in Kerala, India
Authors: R. Sathishwaran , S. Helen , S. Darsana
Published: September 2024

In India, about 75 percent of the population is dependent directly or indirectly on the agricultural and allied sectors. Around 70 percent of the population depends on agriculture for their livelihood. Agriculture development not only involves crop production but also, the development of its stakeholders viz., farmers, fertilizer dealers, extension workers, NGOs, etc. Effective transfer of technology from research to farmers through appropriate stakeholders is crucial for achieving desired results. Fertilizer dealers, as key stakeholders, play an essential role in ensuring farmers have access to essential agricultural inputs needed to enhance productivity on their farms. Several programs have been launched to enhance the capabilities of these agricultural advisors. One such initiative is the 'Certificate Course on Integrated Nutrient Management for Fertilizer Dealers’. Consequently, this study was focused to study the profile characteristics of fertilizer dealers. Ex-post facto research design was adopted for the study with a sample of 300 respondents covering 7 districts of Kerala. From the analysis, it was found that majority of respondents were under medium profile characteristics. In light of these findings, it is advisable to implement refresher training during the off-peak season. This training will enhance dealers' knowledge and skills, enabling them to provide more effective guidance and support to farmers.
Exploring Women’s Economic Empowerment Programme and its Sustainability Issues: A Case of Chadiza District, Eastern Province, Zambia
Authors: Chulu Tuke
Published: September 2024

The study explored women’s economic empowerment programme and assessed its sustainability in Chadiza District of Eastern Province, Zambia. The objectives were firstly, to find out existing programmes for women’s empowerment. Secondly, the study dares to examine how the existing empowerment programmes impacted on the women’s lives. Thirdly, to suggest women’s economic empowerment sustainability strategies. This was a case study analysis and used qualitative and exploratory research method to provide a profound understanding of a research problem. The study sample consisted of 14 participants: 12 women from Ebenezar club and 2 officers from SOS Children’s Villages. Snowball and purposive sampling were used. Data was collected through questionnaires, interview and observation guide. The results of the study were discussed in reference to thematic areas of the findings and they established that empowerment programmes existed in Chadiza and did very well when the project was in implementation. However, sustainability of empowerment programmes was found to be a serious problem. Several issues affected sustainability of the programmes after the project period. As such, the study came up with some strategies, elements and values that would help women sustain empowerment programmes. Furthermore, the study suggested a model that could be employed to help ensure that women’s economic empowerment was properly sustained and bore positive impact. The author anticipated that this study would help politicians, the government, NGOs and even individuals with capacities to allocate and prioritise result oriented, realistic economic empowerment to women and eliminate all negative aspects to guarantee sustainability. The study recommended that the Zambian government should abridge the procedure for accessing CDF, depoliticize and avoid discrimination of who is to access women’s benefits. Monitoring and trainings were also other aspects suggested for effective empowerment activities.
Etiologies and Associated Factors Death Among People Living with the Human Immunodeficiency Virus (PLHIV) Hospitalized for Febrile Consciousness Disorders in the Infectious and Tropical Diseases Departmentof the Donka National Hospital, Guinea
Authors: DIALLO Mamadou Oury Safiatou , BAH Ibrahima , SYLLA Karamba , DIALLO Amadou Daye , SAKO Fodé Bangaly , SOW Mamadou Saliou
Published: September 2024

Introduction: Central nervous system (CNS) damage is common duringhuman immunodeficiency virus (HIV) infectionand occur in cases of immunosuppression, which leads to altered consciousness. The objective of this work was to identify the etiologies and factors associated with the death ofPLHIVhospitalized for febrile consciousness disorders in the infectious and tropical diseases departmentfrom Donka National Hospital.
Methodology: This was a retrospective study of descriptive and analytical type over five (5) years in the infectious and tropical diseases department of the Donka National Hospital. Included in this study werePLHIV under treatment antiretroviraL(ART)or not, aged over 15, hospitalized in the infectious diseases department of Donka National Hospital. for febrile consciousness disorders or those who developed it during the study period.
The parameters studied were sociodemographic characteristics, clinical picture, clinical staging of HIV/Acquired Immuno-Deficiency Syndrome(AIDS) according tothe World Health Organization(WHO).
Factors associated with deaths were searched from logistic regression in multivariate analysis and all variables with a value of P˂0.05 were considered statistically significant.
Results: Two hundred and five out of five hundred and thirty-four (205/534) files ofPLHIV, hospitalized for febrile consciousness disorderswere sampled and enrolled for this studyi.e. a prevalence of 38.39%. The average age of the patients was 42.28 ± 12.54 years with a sex ratio of 0.97. Cerebral toxoplasmosis was the most common etiology.Severe immunosuppression was one of the factors statistically associated with death.           
Conclusion: Febrile consciousness disorders remain very common, with multiple etiologies inPLHIV. The CD4 count ≤ 200 cells/mm3, the depth of the coma and the absence of antiretroviral treatment were the factors associated with death.
Characterization of Freeze-dried Pumpkin Powders: Powder Quality and Nutrient Stability
Authors: B.S Swathi, , C. Mini,
Published: September 2024

Being a good source of nutrients, viz., ascorbic acid, β-carotene, phenols, and antioxidants, pumpkin pulp (Cucurbita moschata) can be utilised as a functional ingredient in many food products by converting them into a more stable product like pumpkin powder. Hence the present study is focused on the production of freeze-dried pumpkin powder by two different methods (drying in petri plates with 5mm sample thickness and in 250 ml flask). The moisture content and water activity were reduced by 92.50% and 74.73%, respectively, compared to the fresh pumpkin pulp, indicating safe storage limits. Freeze-dried pumpkin powders exhibited a decrease of 25% ascorbic acid, 21.58% β-carotene, 39.39% reduction in total polyphenols and 72.98% in antioxidant content. The powder properties of the developed freeze-dried powders exhibited water activity of 0.4aw to 0.35aw bulk density of 0.15 to 0.12 g cm-3, and flow ability of 18.39° to 22.74°.
Phytochemical Characterization and Investigation of Anthelminthic, Antidiabetic, and Toxicological Effects of Polyscias scutellaria
Authors: Akter Jakiya , Nazim Nafiza Binte , Uddin Md. Salah , Shomudro Hasib Khan
Published: September 2024

Aim: Research findings indicate that MEPSL exhibits Very significant anthelmintic, antidiabetic, and moderate toxicological properties. They may endorse the plant's utilization in mainstream medicine for reducing drug intoxication, and managing diabetes and parasitic disorders.
Place and Duration of Study: The research was undertaken at Stamford University Bangladesh during the period from September 6th, 2023 to April 28th, 2024.
Methodology: The current study examined the properties of Polyscias scutellaria leaf, including its In vitro anthelminthic, In vivo antidiabetic, and toxicological effects, using a crude methanol extract. The leaf powder of the dried plant was extracted using methanol. After phytochemical screening, the methanolic extract (MEPSL) underwent additional testing to evaluate its anthelminthic, antidiabetic, and toxicological activities. The earthworm assay was utilized to conduct anthelminthic testing with various concentrations. A study was conducted on Swiss albino mice to evaluate the antidiabetic effects. The Blood Glucose Determination test was performed using doses of 150 mg/kg and 300 mg/kg.  The toxicological tests for acute toxicity were conducted using cinnamon oil at doses of 3000, 5000, and 7000 mg/kg.  During the phytochemical screening process, compounds such as carbohydrates, alkaloids, glycosides, saponins, flavonoids, and reducing sugars were found in MEPSL. 
Results: According to the MEPSL findings, the earthworm met its demise after 30 minutes and 24 seconds during the 100 mg/mL anthelminthic test. In contrast, Albendazole took a significantly longer time of 38 minutes and 18 seconds to achieve the same result.  MEPSL showed a remarkable reduction in blood glucose levels compared to the standard Glibenclamide. In toxicological testing, a dosage of 5000 mg/kg resulted in the mortality of 3 out of 5 mice, while the application of cinnamon oil led to the death of all 5 mice within 24 hours.
Conclusion: Research findings suggest that MEPSL possesses highly significant anthelmintic and antidiabetic properties, along with moderate toxicological effects. These findings may support the integration of the plant into conventional medicine for mitigating drug toxicity and treating diabetes and parasitic infections.
Relationship between Scientific Management Practices Followed by Fish Farmers with their Socio-economic Profile Characteristics
Authors: B. Prashanth , K. K. Shashidhara , Vaishnavi C. , Goudappa S. B. , Reddy B. S. , A. C. Sudhakar
Published: September 2024

This study investigates the relationship between the adoption of scientific management practices by fish farmers and their socio-economic profile characteristics in the Raichur district of Karnataka, India. Using an ex-post-facto research design, data were collected from 120 fish farmers across eight villages. The results indicate that 36.28% of farmers adopted scientific management practices at a medium level, while 33.72% and 30.00% reported low and high adoption levels, respectively. Key socio-economic factors influencing adoption included education, social participation, extension orientation, and mass media utilization. These findings underscore the need for targeted interventions to enhance adoption rates and improve fish farming productivity, thereby supporting rural economies. This revised abstract maintains the essential details while improving clarity and focus.
Topographic variability and the influence of soil erosion on the carbon cycle
Authors: Dialynas Yannis G. , Bastola Satish , Bras Rafael L. , Billings Sharon A. , Markewitz Daniel , Richter Daniel deB.
Published: April 2016

Soil erosion, particularly that caused by agriculture, is closely linked to the global carbon (C) cycle. There is a wide range of contrasting global estimates of how erosion alters soil‐atmosphere C exchange. This can be partly attributed to limited understanding of how geomorphology, topography, and management practices affect erosion and oxidation of soil organic C (SOC). This work presents a physically based approach that stresses the heterogeneity at fine spatial scales of SOC erosion, SOC burial, and associated soil‐atmosphere C fluxes. The Holcombe's Branch watershed, part of the Calhoun Critical Zone Observatory in South Carolina, USA, is the case study used. The site has experienced some of the most serious agricultural soil erosion in North America. We use SOC content measurements from contrasting soil profiles and estimates of SOC oxidation rates at multiple soil depths. The methodology was implemented in the tRIBS‐ECO (Triangulated Irregular Network‐based Real‐time Integrated Basin Simulator‐Erosion and Carbon Oxidation), a spatially and depth‐explicit model of SOC dynamics built within an existing coupled physically based hydro‐geomorphic model. According to observations from multiple soil profiles, about 32% of the original SOC content has been eroded in the study area. The results indicate that C erosion and its replacement exhibit significant topographic variation at relatively small scales (tens of meters). The episodic representation of SOC erosion reproduces the history of SOC erosion better than models that use an assumption of constant erosion in space and time. The net atmospheric C exchange at the study site is estimated to range from a maximum source of 14.5 g m−2 yr−1 to a maximum sink of −18.2 g m−2 yr−1. The small‐scale complexity of C erosion and burial driven by topography exerts a strong control on the landscape's capacity to serve as a C source or a sink.
Particulate organic carbon and nitrogen export from major Arctic rivers
Authors: McClelland J. W. , Holmes R. M. , Peterson B. J. , Raymond P. A. , Striegl R. G. , Zhulidov A. V. , Zimov S. A. , Zimov N. , Tank S. E. , Spencer R. G. M. , Staples R. , Gurtovaya T. Y. , Griffin C. G.
Published: April 2016

Northern rivers connect a land area of approximately 20.5 million km2 to the Arctic Ocean and surrounding seas. These rivers account for ~10% of global river discharge and transport massive quantities of dissolved and particulate materials that reflect watershed sources and impact biogeochemical cycling in the ocean. In this paper, multiyear data sets from a coordinated sampling program are used to characterize particulate organic carbon (POC) and particulate nitrogen (PN) export from the six largest rivers within the pan‐Arctic watershed (Yenisey, Lena, Ob', Mackenzie, Yukon, Kolyma). Together, these rivers export an average of 3055 × 109 g of POC and 368 × 109 g of PN each year. Scaled up to the pan‐Arctic watershed as a whole, fluvial export estimates increase to 5767 × 109 g and 695 × 109 g of POC and PN per year, respectively. POC export is substantially lower than dissolved organic carbon export by these rivers, whereas PN export is roughly equal to dissolved nitrogen export. Seasonal patterns in concentrations and source/composition indicators (C:N, δ13C, Δ14C, δ15N) are broadly similar among rivers, but distinct regional differences are also evident. For example, average radiocarbon ages of POC range from ~2000 (Ob') to ~5500 (Mackenzie) years before present. Rapid changes within the Arctic system as a consequence of global warming make it challenging to establish a contemporary baseline of fluvial export, but the results presented in this paper capture variability and quantify average conditions for nearly a decade at the beginning of the 21st century.
Seasonal and diurnal variations in AMPERE observations of the Birkeland currents compared to modeled results
Authors: Coxon J. C. , Milan S. E. , Carter J. A. , Clausen L. B. N. , Anderson B. J. , Korth H.
Published: April 2016

We reduce measurements made by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) to give the total Birkeland (field‐aligned) current flowing in both hemispheres in monthly and hourly bins. We analyze these totals using 6 years of data (2010–2015) to examine solar zenith angle‐driven variations in the total Birkeland current flowing in both hemispheres, simultaneously, for the first time. A diurnal variation is identified in the total Birkeland current flowing, consistent with variations in the solar zenith angle. A seasonal variation is also identified, with more current flowing in the Northern (Southern) Hemisphere during Bartels rotations in northern (southern) summer. For months close to equinox, more current is found to flow in the Northern Hemisphere, contrary to our expectations. We also conduct the first test of the Milan (2013) model for estimating Birkeland current magnitudes, with modifications made to account for solar contributions to ionospheric conductance based on the observed variation of the Birkeland currents with season and time of day. The modified model, using the value of ΦD averaged by Bartels rotation (scaled by 1.7), is found to agree with the observed AMPERE currents, with a correlation of 0.87 in the Northern Hemisphere and 0.86 in the Southern Hemisphere. The improvement over the correlation with dayside reconnection rate is demonstrated to be a significant improvement to the model. The correlation of the residuals is found to be consistent with more current flowing in the Northern Hemisphere. This new observation of systematically larger current flowing in the Northern Hemisphere is discussed in the context of previous results which suggest that the Northern Hemisphere may react more strongly to dayside reconnection than the Southern Hemisphere.
Changing black carbon transport to the Arctic from present day to the end of 21st century
Authors: Jiao Chaoyi , Flanner Mark G.
Published: April 2016

Here we explore how climate warming under the Representative Concentration Pathway 8.5 (RCP8.5) impacts Arctic aerosol distributions via changes in atmospheric transport and removal processes. We modify the bulk aerosol module in the Community Atmosphere Model to track distributions and fluxes of 200 black carbon‐like tracers emitted from different locations, and we conduct idealized experiments with and without active aerosol deposition. Changing wind patterns, studied in isolation, cause the Arctic burdens of tracers emitted from East Asia and West Europe during winter to increase about 20% by the end of the century while decreasing the Arctic burdens of North American emissions by about 30%. These changes are caused by an altered winter polar dome structure that results from Arctic amplification and inhomogeneous sea ice loss and surface warming, both of which are enhanced in the Chukchi Sea region. The resulting geostrophic wind favors Arctic transport of East Asian emissions while inhibiting poleward transport of North American emissions. When active deposition is also considered, however, Arctic burdens of emissions from northern midlatitudes show near‐universal decline. This is a consequence of increased precipitation and wet removal, particularly within the Arctic, leading to decreased Arctic residence time. Simulations with present‐day emissions of black carbon indicate a 13.6% reduction in the Arctic annual mean burden by the end of the 21st century, due to warming‐induced transport and deposition changes, while simulations with changing climate and emissions under RCP8.5 show a 61.0% reduction.
Reassessing changes in diurnal temperature range: Intercomparison and evaluation of existing global data set estimates
Authors: Thorne P. W. , Donat M. G. , Dunn R. J. H. , Williams C. N. , Alexander L. V. , Caesar J. , Durre I. , Harris I. , Hausfather Z. , Jones P. D. , Menne M. J. , Rohde R. , Vose R. S. , Davy R. , Klein‐Tank A. M. G. , Lawrimore J. H. , Peterson T. C. , Rennie J. J.
Published: April 2016

Changes in diurnal temperature range (DTR) over global land areas are compared from a broad range of independent data sets. All data sets agree that global‐mean DTR has decreased significantly since 1950, with most of that decrease occurring over 1960–1980. The since‐1979 trends are not significant, with inter‐data set disagreement even over the sign of global changes. Inter‐data set spread becomes greater regionally and in particular at the grid box level. Despite this, there is general agreement that DTR decreased in North America, Europe, and Australia since 1951, with this decrease being partially reversed over Australia and Europe since the early 1980s. There is substantive disagreement between data sets prior to the middle of the twentieth century, particularly over Europe, which precludes making any meaningful conclusions about DTR changes prior to 1950, either globally or regionally. Several variants that undertake a broad range of approaches to postprocessing steps of gridding and interpolation were analyzed for two of the data sets. These choices have a substantial influence in data sparse regions or periods. The potential of further insights is therefore inextricably linked with the efficacy of data rescue and digitization for maximum and minimum temperature series prior to 1950 everywhere and in data sparse regions throughout the period of record. Over North America, station selection and homogeneity assessment is the primary determinant. Over Europe, where the basic station data are similar, the postprocessing choices are dominant. We assess that globally averaged DTR has decreased since the middle twentieth century but that this decrease has not been linear.
Assessment of aerosol optical property and radiative effect for the layer decoupling cases over the northern South China Sea during the 7‐SEAS/Dongsha Experiment
Authors: Pani Shantanu Kumar , Wang Sheng‐Hsiang , Lin Neng‐Huei , Tsay Si‐Chee , Lolli Simone , Chuang Ming‐Tung , Lee Chung‐Te , Chantara Somporn , Yu Jin‐Yi
Published: April 2016

The aerosol radiative effect can be modulated by the vertical distribution and optical properties of aerosols, particularly when aerosol layers are decoupled. Direct aerosol radiative effects over the northern South China Sea (SCS) were assessed by incorporating an observed data set of aerosol optical properties obtained from the Seven South East Asian Studies (7‐SEAS)/Dongsha Experiment into a radiative transfer model. Aerosol optical properties for a two‐layer structure of aerosol transport were estimated. In the radiative transfer calculations, aerosol variability (i.e., diversity of source region, aerosol type, and vertical distribution) for the complex aerosol environment was also carefully quantified. The column‐integrated aerosol optical depth (AOD) at 500 nm was 0.1–0.3 for near‐surface aerosols and increased 1–5 times in presence of upper layer biomass‐burning aerosols. A case study showed the strong aerosol absorption (single‐scattering albedo (ω) ≈ 0.92 at 440 nm wavelength) exhibited by the upper layer when associated with predominantly biomass‐burning aerosols, and the ω (≈0.95) of near‐surface aerosols was greater than that of the upper layer aerosols because of the presence of mixed type aerosols. The presence of upper level aerosol transport could enhance the radiative efficiency at the surface (i.e., cooling) and lower atmosphere (i.e., heating) by up to −13.7 and +9.6 W m−2 per AOD, respectively. Such enhancement could potentially modify atmospheric stability, can influence atmospheric circulation, as well as the hydrological cycle over the tropical and low‐latitude marginal northern SCS.
Catchment‐ and reach‐scale controls on the distribution and expectation of geomorphic channel adjustment
Authors: Lisenby Peyton E. , Fryirs Kirstie A.
Published: April 2016

Variability in channel function (behavior) can be assessed by characterizing different forms of adjustment over time. Here, historical channel adjustments in three tributary systems of the Lockyer Valley, Southeast Queensland (SEQ) are analyzed in order to evaluate the range of catchment‐ and reach‐scale controls on channel behavior. Over 300 individual adjustments and 13 forms of adjustment were identified over a ∼130 year time span. We measured the width‐to‐depth ratio (W:D), mean stream power (ω), and basin area (A) at the location of all observed adjustments. The most common forms of adjustment were avulsions, lateral expansion of the channel, and bend adjustments. The tributary systems behave distinctly different from one another according to statistical comparisons between the W:D, ω, and A data for these forms of adjustment. We find that it is possible to develop process domains or typologies for forms of geomorphic adjustment found in the Lockyer Valley. These domains or typologies provide the foundations for synoptic comparisons between catchments and assessing the expectation of channel adjustment (forecasting), which should be included in process‐based river management practice.
Valuing year‐to‐go hydrologic forecast improvements for a peaking hydropower system in the Sierra Nevada
Authors: Rheinheimer David E. , Bales Roger C. , Oroza Carlos A. , Lund Jay R. , Viers Joshua H.
Published: April 2016

We assessed the potential value of hydrologic forecasting improvements for a snow‐dominated high‐elevation hydropower system in the Sierra Nevada of California, using a hydropower optimization model. To mimic different forecasting skill levels for inflow time series, rest‐of‐year inflows from regression‐based forecasts were blended in different proportions with representative inflows from a spatially distributed hydrologic model. The statistical approach mimics the simpler, historical forecasting approach that is still widely used. Revenue was calculated using historical electricity prices, with perfect price foresight assumed. With current infrastructure and operations, perfect hydrologic forecasts increased annual hydropower revenue by $0.14 to $1.6 million, with lower values in dry years and higher values in wet years, or about $0.8 million (1.2%) on average, representing overall willingness‐to‐pay for perfect information. A second sensitivity analysis found a wider range of annual revenue gain or loss using different skill levels in snow measurement in the regression‐based forecast, mimicking expected declines in skill as the climate warms and historical snow measurements no longer represent current conditions. The value of perfect forecasts was insensitive to storage capacity for small and large reservoirs, relative to average inflow, and modestly sensitive to storage capacity with medium (current) reservoir storage. The value of forecasts was highly sensitive to powerhouse capacity, particularly for the range of capacities in the northern Sierra Nevada. The approach can be extended to multireservoir, multipurpose systems to help guide investments in forecasting.
Regional‐scale controls on dissolved nitrous oxide in the Upper Mississippi River
Authors: Turner P. A. , Griffis T. J. , Baker J. M. , Lee X. , Crawford J. T. , Loken L. C. , Venterea R. T.
Published: April 2016

The U.S. Corn Belt is one of the most intensive agricultural regions of the world and is drained by the Upper Mississippi River (UMR), which forms one of the largest drainage basins in the U.S. While the effects of agricultural nitrate (NO3−) on water quality in the UMR have been well documented, its impact on the production of nitrous oxide (N2O) has not been reported. Using a novel equilibration technique, we present the largest data set of freshwater dissolved N2O concentrations (0.7 to 6 times saturation) and examine the controls on its variability over a 350 km reach of the UMR. Driven by a supersaturated water column, the UMR was an important atmospheric N2O source (+68 mg N2O N m−2 yr−1) that varies nonlinearly with the NO3− concentration. Our analyses indicated that a projected doubling of the NO3− concentration by 2050 would cause dissolved N2O concentrations and emissions to increase by about 40%.
The effects of plasmaspheric plumes on dayside reconnection
Authors: Ouellette J. E. , Lyon J. G. , Brambles O. J. , Zhang B. , Lotko W.
Published: April 2016

We summarize the results of a study on the impact of plasmaspheric plumes on dayside reconnection using a three‐dimensional magnetospheric simulation code. We find that the mass loading of magnetospheric flux tubes slows local reconnection rates, though not as much as predicted by Borovsky et al. (2013) due to differences in how well the Cassak‐Shay theory matches magnetospheric configurations with and without plasmaspheric plumes. Additionally, we find that in some circumstances reconnection activity is enhanced on either side of the plumes, which moderates its impact on the total dayside reconnection rate. These results provide evidence that plasmaspheric plumes have both local‐ and global‐scale effects on dayside reconnection.
Characterization of AmtA, an amidinotransferase involved in the biosynthesis of phaseolotoxins
Authors: Li Mi , Chen Li , Deng Zixin , Zhao Changming
Published: April 2016

Phaseolotoxins (PHTs), which are produced by Pseudomonas, belong to a family of phosphoramidate natural products. Two nonproteinogenic amino acid precursors, Nδ(N′‐sulfo‐diaminophosphinyl)‐ornithine (PSOrn) and homoarginine (hArg), are involved in biosynthesis of PHTs. Amidinotransferase AmtA catalyses the formation of hArg, with arginine and lysine as substrates. AmtA was overexpressed and purified in an Escherichia coli system. An in vitro enzyme assay showed that it has stricter substrate specificity than certain other amidinotransferases. Site‐directed mutagenesis experiments showed that the mutation AmtA Met243His244 is an alternative while Met246 is essential for the transamidination activity.
Outer‐sphere residues influence the catalytic activity of a chalcone synthase from Polygonum cuspidatum
Authors: Shen Yalin , Li Xing , Chai Tuanyao , Wang Hong
Published: April 2016

We have previously cloned a chalcone synthase (PcCHS1) from Polygonum cuspidatum and biochemically identified its enzymatic dynamic properties. Here, we found that the outer sphere residues, Q82 and R105, could affect the catalytic activity and product profile of PcCHS1. Both Q82P and R105Q mutations of PcCHS1 could also change the pH dependence activity as well as the product profile of PcCHS1. Moreover, the Q82P/C198F double mutant could rescue the complete loss of enzyme activity caused by the C198F single mutation. Our study demonstrated that these outer‐sphere residues of PcCHS1 play important roles both in structural maintenance and enzyme activity.
Anti‐EGFR scFv tetramer (tetrabody) with a stable monodisperse structure, strong anticancer effect, and a long in vivo half‐life
Authors: Asano Ryutaro , Koyama Noriaki , Hagiwara Yasuyo , Masakari Yosuke , Orimo Ryota , Arai Kyoko , Ogata Hiromi , Furumoto Shozo , Umetsu Mitsuo , Kumagai Izumi
Published: April 2016

The development of single‐chain variable fragments (scFvs) as therapeutic agents has the potential to reduce the high cost of antibody production, but the development process often impairs scFv functions such as binding affinity and pharmacokinetics. Multimerization is one strategy for recovering or enhancing these lost functions. Previously, we constructed several antiepidermal growth factor receptor (EGFR) scFv multimers by modifying linker length and domain order. Antitumor effects comparable with those of the currently approved anti‐EGFR therapeutic antibodies were observed for scFv trimers. In the present study, we fractionated an anti‐EGFR scFv tetramer from the intracellular soluble fraction of an Escherichia coli transformant. Compared with the trimer, the tetramer showed higher affinity, greater cancer cell growth inhibition, and prolonged blood retention time. Furthermore, the tetramer did not dissociate into the trimer or other smaller species during long‐term storage (up to 33 weeks). Thus, our developed scFv tetramer is an attractive candidate next‐generation anti‐EGFR therapeutic antibody that can be produced via a low‐cost bacterial expression system.
Estimation of Surface Topography and Wear Loss of Laser Metal‐Deposited Ti6Al4V and Cu
Authors: Erinosho Mutiu F. , Akinlabi Esther T.
Published: April 2016

The atomic force microscopy (AFM) analysis is a process that involves the detailed analyses of the surface of a three‐dimensional sample piece. A good image is always generated on such a sample once the settings are implemented correctly. And as such, the amplitude set point plays a vital role in achieving a better image. This paper presents the evolving microstructures and the surface topographies of the laser‐deposited Ti6Al4V/Cu alloys. The formation and the output of the microstructure depend on the laser processing parameters employed. The migration of the β‐phase has been impeded during solidification due to the low strain hardening effect posed by the α‐Ti lamella. A correlation between wear loss and surface roughness has been established among the laser‐deposited samples.
Stretchable Hexagonal Diffraction Gratings as Optical Diffusers for In Situ Tunable Broadband Photon Management
Authors: Mahpeykar Seyed Milad , Xiong Qiuyang , Wei Jue , Meng Lingju , Russell Brandon K. , Hermansen Peter , Singhal Akshay V. , Wang Xihua
Published: April 2016

A stretchable transmissive hexagonal diffraction grating, which has the potential to act as an optical diffuser, is demonstrated. Leveraging the simplicity of the self‐assembly fabrication process, the photon manipulation capability of polystyrene nanosphere arrays, and elastomeric properties of polydimethylsiloxane, the proposed device is capable of reproducible in situ tuning of both diffraction efficiency and spectral range. While being able to achieve maximum diffraction efficiencies of about 80%, the device displays highly efficient and broadband light diffusion fairly independent of incident light polarization and angle of incidence. Due to its efficient and tunable diffraction capabilities, one potential application of the reported device can be broadband photon management in solar cells and photodetectors by significant increase of the light path length inside the light‐absorbing thin films of these devices. As a proof of concept, the proposed optical diffuser is utilized for light absorption enhancement in colloidal quantum dot semiconductor thin films. The demonstrated devices enable integration of cheap and widely used materials with simple cost‐effective fabrication for photon management in optics, photonics, and optoelectronics.
Fabrication of Ti3C2Tx MXene Transparent Thin Films with Tunable Optoelectronic Properties
Authors: Hantanasirisakul Kanit , Zhao Meng‐Qiang , Urbankowski Patrick , Halim Joseph , Anasori Babak , Kota Sankalp , Ren Chang E. , Barsoum Michel W. , Gogotsi Yury
Published: April 2016

MXenes, a new class of 2D transition metal carbides and carbonitrides, show great promise in supercapacitors, Li‐ion batteries, fuel cells, and sensor applications. A unique combination of their metallic conductivity, hydrophilic surface, and excellent mechanical properties renders them attractive for transparent conductive electrode application. Here, a simple, scalable method is proposed to fabricate transparent conductive thin films using delaminated Ti3C2 MXene flakes by spray coating. Homogenous films, 5–70 nm thick, are produced at ambient conditions over a large area as shown by scanning electron microscopy and atomic force microscopy. The sheet resistances (Rs) range from 0.5 to 8 kΩ sq−1 at 40% to 90% transmittance, respectively, which corresponds to figures of merit (the ratio of electronic to optical conductivities, σDC/σopt) around 0.5–0.7. Flexible, transparent, and conductive films are also produced and exhibit stable Rs values at up to 5 mm bend radii. Furthermore, the films' optoelectronic properties are tuned by chemical or electrochemical intercalation of cations. The films show reversible changes of transmittance in the UV–visible region during electrochemical intercalation/deintercalation of tetramethylammonium hydroxide. This work shows the potential of MXenes to be used as transparent conductors in electronic, electrochromic, and sensor applications.
A hybrid approach to computing electrostatic forces in fluidized beds of charged particles
Authors: Kolehmainen Jari , Ozel Ali , Boyce Christopher M. , Sundaresan Sankaran
Published: April 2016

In particulate flow devices particles acquire electric charge through triboelectric charging, and resulting electrostatic forces can alter hydrodynamics. To capture this effect, the electrostatic force acting on individual particles in the device should be computed accurately. Electrostatic force is calculated using a hybrid approach consisting of: (1) long‐range contributions from an Eulerian electric field solved using the Poisson equation (2) short‐range contributions calculated using a truncated pairwise sum and (3) a correction to avoid double counting. Euler‐Lagrange simulation of flows incorporating this hybrid approach reveals that bed height oscillations in small fluidized beds of particles with monopolar charge decreases with increasing charge level, which is related to lateral segregation of particles. A ring‐like layer of particles, reported in experimental studies, forms at modestly high charge levels. Beds with equal amounts of positively and negatively charged particles are fluidized in a manner similar to uncharged particles. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2282–2295, 2016
Control structure selection based on economics: Generalization of the back‐off methodology
Authors: Kookos Ioannis K. , Perkins John D.
Published: April 2016

The back‐off methodology has been extensively developed and refined in the last 20 years and offers a systematic tool for solving the simultaneous design and control problem. Previous work has been based on linear process and control models that ensure quick determination of the optimal solution at the expense of potential loss in the accuracy due to nonlinear process characteristics. In this work a new formulation is proposed where use is made of a nonlinear process model that ensures improved accuracy and also offers an improved opportunity for the simultaneous consideration of process design and process control. Two case studies are studied in detail and demonstrate the advantages of the new formulation. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3056–3064, 2016
Covariance‐based hardware selection part IV: Solution using the generalized benders decomposition
Authors: Zhang Jin , Wang Xiaoxi , Chmielewski Donald J.
Published: April 2016

Recently the covariance based hardware selection problem has been shown to be of the mixed integer convex programming (MICP) class. While such a formulation provides a route to global optimality, use of the branch and bound search procedure has limited application to fairly small systems. The particular bottleneck is that during each iteration of the branch and bound search, a fairly slow semi‐definite programming (SDP) problem must be solved to its global optimum. In this work, we illustrate that a simple reformulation of the MICP and subsequent application of the generalized Benders decomposition algorithm will result in massive reductions in computational effort. While the resulting algorithm must solve multiple mixed integer linear programs, this increase in computational effort is significantly outweighed by the reduction in the number of SDP problems that must be solved. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3628–3638, 2016