1,115 research outputs found
Grain zinc and yield responses of two rice varieties to zinc biofortification and water management
Zinc (Zn) biofortification can improve grain yield and nutritional quality in rice, but its effectiveness is subject to agronomic practices and other factors. In a previous study, the application of Zn to soil enhanced grain Zn in lowland rice in well-drained and waterlogged soil, whereas grain Zn in upland rice increased only in well-drained soil. This new study explores the hypothesis that the application of foliar Zn can enhance grain Zn in upland and lowland rice grown under waterlogged and well-drained conditions. Two rice varieties, CNT1 (wetland rice) and KH CMU (upland rice) were grown in containers in waterlogged or well-drained soil with three Zn treatments (no Zn, soil Zn and foliar Zn). For the soil Zn treatment, 50 kg ZnSO4 haâ1 was applied to the soil before transplanting. For the foliar treatment, 0.5% ZnSO4 (equivalent to 900 L haâ1) was applied at booting and repeated at flowering and milky growth stages. Grain yield in CNT1 was 15.9% higher in the waterlogged than in the well-drained plants, but the water regime had no effect on grain yield in KH CMU. Grain Zn concentration in CNT1 increased from 19.5% to 32.6% above the no Zn control when plants were applied with soil or foliar Zn. In KH CMU, there was an interaction between the water regime and Zn treatment. Application of foliar Zn increased grain Zn by 44.6% in well-drained and 14.7% in waterlogged soil. The results indicate strong interaction effects between variety, water regime and Zn fertilizer application on Zn biofortification in rice. Thus, the selection of rice varieties and growing conditions should be considered in order for producers to achieve desirable outcomes from high grain Zn concentrations
Parkinson Disease-Associated Protein α-Synuclein Blocks VDAC Providing New Insights into Mitochondrial Toxicity
Intimate intergroup contact across the lifespan
Intergroup contact can be as casual as members of different groups walking past one another on the street or as intimate as developing crossâgroup friendships or romantic relationships. To date, however, the majority of intergroup contact research has focused on examining the effects of contact through selfâreport measures of interactions and friendships. While this research has made a substantial contribution to scientific understanding, less is known about how different forms of contact (casual vs. intimate) influence each other and are associated with outcomes across the lifespan. The present article focuses on intimate contact; a close and meaningful relationship or interaction with either an ingroup or outgroup member. We critically review the nature and consequences (good and bad) of intimate contact for children, youth and adults and for both majority and minority group members, focusing primarily on intimate intergroup contact. We also consider how intimate contact might be best measured in future research. Implications for research design, policy, and practice are considered
Approximation Algorithm for Line Segment Coverage for Wireless Sensor Network
The coverage problem in wireless sensor networks deals with the problem of
covering a region or parts of it with sensors. In this paper, we address the
problem of covering a set of line segments in sensor networks. A line segment `
is said to be covered if it intersects the sensing regions of at least one
sensor distributed in that region. We show that the problem of finding the
minimum number of sensors needed to cover each member in a given set of line
segments in a rectangular area is NP-hard. Next, we propose a constant factor
approximation algorithm for the problem of covering a set of axis-parallel line
segments. We also show that a PTAS exists for this problem.Comment: 16 pages, 5 figures
Imaging biomarkers of adiposity and sarcopenia as potential predictors for overall survival among patients with endometrial cancer treated with bevacizumab
Objective:To examine associations of body mass index (BMI), subcutaneous fat area (SFA) and density (SFD), visceral fat area (VFA) and density (VFD) and total psoas area (TPA) to outcomes among patients receiving chemotherapy with or without bevacizumab for advanced or recurrent endometrial cancer (EC). Methods:This was a multi-institutional, retrospective study of patients with EC treated with and without bevacizumab as part of front-line, platinum based chemotherapy. Demographics and clinical characteristics were collected. SFA, VFA, SFD, VFD, and TPA were determined from pre-treatment CT scans using a deep learning algorithm. Data was compared with overall survival (OS) and progression free survival (PFS). Results:Seventy-eight patients were analyzed. The majority were Caucasian (87.2%) with a mean BMI of 34.7âŻkg/m2. PFS and OS did not differ between patients with BMI, SFA, VFA, SFD, VFD, or TPAâŻâ„âŻthe 50th percentile compared to <50th percentile (pâŻ=âŻ0.91, 0.45, 0.71, 0.74, 0.60, and 0.74 respectively) and (pâŻ=âŻ0.99, 0.59, 0.14, 0.77, and 0.85 respectively). When adjusting for prognostic factors, elevated VFA trended towards shorter OS (25.1 vs 59.5âŻmonths, HRâŻ=âŻ1.68 [0.92-3.05]).Patients receiving bevacizumab had similar OS compared to those who did not (37.6 vs 44.5âŻmonths, pâŻ=âŻ0.409). When stratified by adiposity markers, no subset demonstrated benefit from bevacizumab. Conclusion:Obesity has been associated with increased levels of vascular endothelial growth factor (VEGF), the main target for bevacizumab therapy. Imaging measurements of VFA may provide prognostic information for patients with EC but no adiposity marker was predictive of improved response to bevacizumab
Improved catalytic activity of rutheniumâarene complexes in the reduction of NAD+
A series of neutral Ru-II half-sandwich complexes of the type [(eta(6)-arene)Ru(N,N')Cl] where the arene is para-cymene (p-cym), hexamethylbenzene (hmb), biphenyl (bip), or benzene (bn) and N,N' is N-(2-aminoethyl) -4-(trifluoromethyl)benzenesulfonamide (TfEn), N-(2-aminoethyl)-4-toluenesulfonamide (TsEn), or N-(2-aminoethyl)-methylenesulfonamide (MsEn) were synthesized and characterized. X-ray crystal structures of [(p-cym)Ru(MsEn)Cl] (1), [(hmb)Ru(TsEn)Cl] (5), [(hmb)Ru(TfEn)Cl] (6), [(bip)Ru(MsEn)Cl] (7), and [(bip)Ru(TsEn)Cl] (8) have been determined. The complexes can regioselectively catalyze the transfer hydrogenation of NAD(+) to give 1,4-NADH in the presence of formate. The turnover frequencies (TOF) when the arene is varied decrease in the order bn > bip > p-cym > hmb for complexes with the same N,N' chelating ligand. The TOF decreased with variation in the N,N' chelating ligand in the order TfEn > TsEn > MsEn for a given arene. [(bn)Ru(TfEn)Cl] (12) was the most active, with a TOP of 10.4 h(-1). The effects of NAD(+) and formate concentration on the reaction rates were determined for [(p-cym)Ru(TsEn)Cl] (2). Isotope studies implicated the formation of [(arene)Ru(N,N')(H)] as the rate-limiting step. The coordination of formate and subsequent CO2 elimination to generate the hydride were modeled computationally by density functional theory (DFT). CO2 elimination occurs via a two-step process with the coordinated formate first twisting to present its hydrogen toward the metal center. The computed barriers for CO2 release for arene = benzene follow the order MsEn > TsEn > TfEn, and for the Ms En system the barrier followed bn < hmb, both consistent with the observed rates. The effect of methanol on transfer hydrogenation rates in aqueous solution was investigated. A study of pH dependence of the reaction in D2O gave the optimum pH* as 7.2 with a TOF of 1.58 h(-1) for 2. The series of compounds reported here show an improvement in the catalytic activity by an order of magnitude compared to the ethylenediamine analogues
Transnational marriages in Yiwu, China: tensions over money
In this article, I explore the role of transnational marriages in the activities and strategies of trading networks, through the lens of money and uncertainty in marriage. I argue that uncertainty in spousal relations challenges the durability of such unions and hence the effectiveness of their role in trading activities. These uncertainties are shaped by intertwined factors, including especially the embedded relationship between commercial and social networks (for example, business partners, kinship, friendship) and spousal relations, the differing cultural values and practices of the partners to such unions, stereotypes, varying forms and degrees of trust and mistrust, and the dynamics of global markets and state policy. Uncertainties driven by these factors exacerbate mistrust in both marriages and trading relations; they also shape shifting orientations toward future life. Therefore, I argue that the role of marriage in trading activities should be neither simplified nor romanticized
Solidarity and Strife After the Atlanta Spa Shootings: A Mixed Methods Study Characterizing Twitter Discussions by Qualitative Analysis and Machine Learning
Background: On March 16, 2021, a white man shot and killed eight victims, six of whom were Asian women at Atlanta-area spa and massage parlors. The aims of the study were to: (1) qualitatively summarize themes of tweets related to race, ethnicity, and racism immediately following the Atlanta spa shootings, and (2) examine temporal trends in expressions hate speech and solidarity before and after the Atlanta spa shootings using a new methodology for hate speech analysis.
Methods: A random 1% sample of publicly available tweets was collected from January to April 2021. The analytic sample included 708,933 tweets using race-related keywords. This sample was analyzed for hate speech using a newly developed method for combining faceted item response theory with deep learning to measure a continuum of hate speech, from solidarity race-related speech to use of violent, racist language. A qualitative content analysis was conducted on random samples of 1,000 tweets referencing Asians before the Atlanta spa shootings from January to March 15, 2021 and 2,000 tweets referencing Asians after the shooting from March 17 to 28 to capture the immediate reactions and discussions following the shootings.
Results: Qualitative themes that emerged included solidarity (4% before the shootings vs. 17% after), condemnation of the shootings (9% after), racism (10% before vs. 18% after), role of racist language during the pandemic (2 vs. 6%), intersectional vulnerabilities (4 vs. 6%), relationship between Asian and Black struggles against racism (5 vs. 7%), and discussions not related (74 vs. 37%). The quantitative hate speech model showed a decrease in the proportion of tweets referencing Asians that expressed racism (from 1.4% 7 days prior to the event from to 1.0% in the 3 days after). The percent of tweets referencing Asians that expressed solidarity speech increased by 20% (from 22.7 to 27.2% during the same time period) (p \u3c 0.001) and returned to its earlier rate within about 2 weeks.
Discussion: Our analysis highlights some complexities of discrimination and the importance of nuanced evaluation of online speech. Findings suggest the importance of tracking hate and solidarity speech. By understanding the conversations emerging from social media, we may learn about possible ways to produce solidarity promoting messages and dampen hate messages
The impact of the demographic transition on dengue in Thailand: Insights from a statistical analysis and mathematical modeling
Background: An increase in the average age of dengue hemorrhagic fever (DHF) cases has been reported in Thailand. The cause of this increase is not known. Possible explanations include a reduction in transmission due to declining mosquito populations, declining contact between human and mosquito, and changes in reporting. We propose that a demographic shift toward lower birth and death rates has reduced dengue transmission and lengthened the interval between large epidemics. Methods and Findings: Using data from each of the 72 provinces of Thailand, we looked for associations between force of infection (a measure of hazard, defined as the rate per capita at which susceptible individuals become infected) and demographic and climactic variables. We estimated the force of infection from the age distribution of cases from 1985 to 2005. We find that the force of infection has declined by 2% each year since a peak in the late 1970s and early 1980s. Contrary to recent findings suggesting that the incidence of DHF has increased in Thailand, we find a small but statistically significant decline in DHF incidence since 1985 in a majority of provinces. The strongest predictor of the change in force of infection and the mean force of infection is the median age of the population. Using mathematical simulations of dengue transmission we show that a reduced birth rate and a shift in the population's age structure can explain the shift in the age distribution of cases, reduction of the force of infection, and increase in the periodicity of multiannual oscillations of DHF incidence in the absence of other changes. Conclusions: Lower birth and death rates decrease the flow of susceptible individuals into the population and increase the longevity of immune individuals. The increase in the proportion of the population that is immune increases the likelihood that an infectious mosquito will feed on an immune individual, reducing the force of infection. Though the force of infection has decreased by half, we find that the critical vaccination fraction has not changed significantly, declining from an average of 85% to 80%. Clinical guidelines should consider the impact of continued increases in the age of dengue cases in Thailand. Countries in the region lagging behind Thailand in the demographic transition may experience the same increase as their population ages. The impact of demographic changes on the force of infection has been hypothesized for other diseases, but, to our knowledge, this is the first observation of this phenomenon
Increased risk of incident dementia following use of anticholinergic agents: A systematic literature review and meta-analysis
Background/rationale: Long-term treatment with anticholinergic agents may increase the risk of cognitive impairment or dementia. This systematic literature review and meta-analysis aimed to assess the impact of â„3 months of exposure to anticholinergics as a class on the risk of dementia, mild cognitive impairment, and change in cognitive function. The impact of anticholinergic agents specifically used to treat overactive bladder was also evaluated. Materials and Methods: A systematic literature review was conducted to identify English language articles evaluating the impact of anticholinergic use for â„3 months on dementia or cognitive function in adult patients. Databases searched included PubMed, Embase, and the Cochrane Library. Meta-analyses were conducted using random-effects models; 95% confidence intervals (CIs) and 95% prediction intervals (PIs) were reported. Results: A total of 2122 records were identified. Out of those, 21 studies underwent qualitative synthesis and 6 reported endpoints relevant for inclusion in a meta-analysis assessing the risk of incident dementia. The overall rate ratio for incident dementia was 1.46 (95% CI: 1.17â1.81; 95% PI: 0.70â3.04; n = 6). The risk of incident dementia increased with increasing exposure (n = 3). In addition, two studies from the meta-analysis reported an increased risk of dementia with â„3 months of use of bladder antimuscarinics (adjusted odds ratios ranged from 1.21 to 1.65, depending on exposure category). Conclusion: Anticholinergic use for â„3 months increased the risk of dementia on average by an estimated 46% versus nonuse. This relationship was consistent in studies assessing overactive bladder medications. The risk of developing dementia should be carefully considered in the context of potential benefit before prescribing anticholinergics
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