Adaptive Responses of \u3cem\u3eBrachiaria\u3c/em\u3e Grasses to Hypoxia Stress

It is likely that oxygen shortage in waterlogged soils is the most limiting factor for plant growth, restricting root aerobic respiration and ATP production (Vartapetian and Jackson 1997). When oxygen becomes limiting for oxidative phosphorylation, plant cells depend on alternative metabolic pathways to produce ATP (Rocha et al. 2010). The induction of fermentative metabolism is considered of adaptive value to maintain ATP production under oxygen-limited conditions. Ethanol is the main end product of fermentation metabolism in plants. Alcohol dehydrogenase (ADH) is a key enzyme in ethanolic fermentation. Roots can sustain aerobic respiration under oxygen deficiency if aerenchyma is present. Aerenchyma commonly refers to tissue containing air-filled spaces that provide oxygen un-der oxygen-limited conditions (Colmer and Voesenek 2009). The main objective of the present study was to determine morpho-physiological adaptive responses of seven Brachiaria genotypes to hypoxia stress

Hypothesis testing with active information

We develop hypothesis testing for active information -the averaged quantity in the Kullback-Liebler divergence. To our knowledge, this is the first paper to derive exact probabilities of type-I errors for hypothesis testing in the area.Comment: Typo changed in one of the names in the Metadata, and a reference to an equation from the paper in the Supplemen

Quantum dot-sensitized solar cells

Quantum dot-sensitized solar cells (QDSCs) have emerged as a promising candidate for next-generation solar cells due to the distinct optoelectronic features of quantum dot (QD) light-harvesting materials, such as high light, thermal, and moisture stability, facilely tunable absorption range, high absorption coefficient, multiple exciton generation possibility, and solution processability as well as their facile fabrication and low-cost availability. In recent years, we have witnessed a dramatic boost in the power conversion efficiency (PCE) of QDSCs from 5% to nearly 13%, which is comparable to other kinds of emerging solar cells. Both the exploration of new QD light-harvesting materials and interface engineering have contributed to this fantastically fast improvement. The outstanding development trend of QDSCs indicates their great potential as a promising candidate for next-generation photovoltaic cells. In this review article, we present a comprehensive overview of the development of QDSCs, including: (1) the fundamental principles, (2) a history of the brief evolution of QDSCs, (3) the key materials in QDSCs, (4) recombination control, and (5) stability issues. Finally, some directions that can further promote the development of QDSCs in the future are proposed to help readers grasp the challenges and opportunities for obtaining high-efficiency QDSCs

Brachiaria Hybrids with Larger Root Length Densities Show Greater Shoot Vigor under Drought

Brachiaria grasses are the most widely planted forages in Tropical America, and their demand is increasing across Africa and South-East Asia. One of the most limiting factors affecting productivity of Brachiaria forage grasses is seasonal drought. Genotypic variation for drought resistance has been found among Brachiaria forage grasses, making possible to genetically improve the productivity of Brachiaria forage grasses under water-limiting conditions (Rao, 2014). The ongoing Brachiaria breeding program at the International Center for Tropical Agriculture (CIAT) has been developing and testing Brachiaria hybrids that combine resistance to biotic constraints with adaptation to abiotic stresses such as drought. Adaptation to drought conditions greatly relies on an efficient root system that facilitates water capture in drying soil. Among root traits, greater root length density (the length of roots per unit volume of soil, RLD cm/cm3) generally indicates greater ability for water uptake in drying soil (Wasson et al., 2012). Screening of forage germplasm for resistance to drought conditions has often overlooked root traits. This is because of the difficulty to separate roots out of soil, which inevitably ends up in a very low-through-put system. However, new imaging techniques allow rapid estimation and quantification of RLD within the soil (i.e., without the need to separate roots from soil). The following work was therefore performed to evaluate the variation in dry mass, water uptake and RLD of 103 hybrids of Brachiaria after three weeks of growth under drought conditions. We hypothesized that hybrids with greater RLD could extract (particularly with increasing depth) more water in drying soil, which in turn is reflected in greater shoot dry mass production after three weeks of drought treatment

Sleep duration and patterns in Chinese older adults: A comprehensive meta-analysis

This meta-analysis examined the mean sleep duration and patterns in Chinese older adult population. A literature search was systematically conducted covering major English (PubMed, Embase and PsycINFO) and Chinese (Chinese National Knowledge Infrastructure (CNKI), WanFang and SinoMed) databases. Data in studies with the mean and standard deviation of sleep duration and/or the proportion of short and long sleep durations in Chinese older adults were extracted and pooled using random-effects models. Subgroup analyses were conducted according to gender, region, area, survey time and sample size. A total of 36 studies with 150,616 subjects were included for analyses. The pooled mean sleep duration of 21 studies with available data was 6.82 hours/day (95% CI: 6.59–7.05 hours/day). The estimated proportions of sleep duration \u3c5 hours/day, \u3c6 hours/day, \u3c7 hours/day were 18.8% (95% CI: 1.7%–35.9%), 26.7% (95% CI: 19.7%–33.7%) and 42.3% (95% CI: 34.8%–49.8%), respectively. The pooled proportions for long sleepers were 22.6% (95% CI: 13.9%–31.4%) (\u3e8 hours/day) and 17.6% (95% CI: 12.4%–22.9%) (\u3e9 hours/day). Given the adverse effects of unhealthy sleep patterns, health professionals should pay more attention to sleep patterns in this population in China

Colorectal cancer screening with fecal occult blood test: A 22-year cohort study.

The aim of the present study was to investigate the efficacy of colorectal cancer (CRC) screening with a three-tier fecal occult blood test (FOBT) in the Chinese population. The study was performed between 1987 and 2008 at the Beijing Military General Hospital, in a cohort of army service males and females aged >50 years. Between 1987 and 2005, a three-tier screening program, comprising guaiac-based FOBTs (gFOBTs), followed by immunochemical FOBTs for positive guaiac test samples and then colonoscopy for positive immunochemical test subjects, was performed annually. The cohort was followed up until 2008. The cohort included 5,104 subjects, of which, 3,863 subjects participated in screening (screening group) and 1,241 did not (non-screening group). The two groups did not differ in age, gender or other major risk factors for colon cancer. Overall, 36 CRCs occurred in the screening group and 21 in the non-screening group. Compared with the non-screening group, the relative risk for the incidence and mortality of CRC was 0.51 [95% confidence interval (CI), 0.30-0.87] and 0.36 (95% CI, 0.18-0.71), respectively, in the screening group. The general sensitivity of this three-tier FOBT was 80.6% (95% CI, 65.3-91.1). Thus, annual screening using the three-tier FOBT program may reduce the CRC incidence and mortality rate

Dislocation constriction and cross-slip in Al and Ag: an ab initio study

A novel model based on the Peierls framework of dislocations is developed. The new theory can deal with a dislocation spreading at more than one slip planes. As an example, we study dislocation cross-slip and constriction process of two fcc metals, Al and Ag. The energetic parameters entering the model are determined from ab initio calculations. We find that the screw dislocation in Al can cross-slip spontaneously in contrast with that in Ag, which splits into partials and cannot cross-slip without first being constricted. The dislocation response to an external stress is examined in detail. We determine dislocation constriction energy and critical stress for cross-slip, and from the latter, we estimate the cross-slip energy barrier for the straight screw dislocations

Short-range spatial variability of soil physico-chemical variables related to earthworm clustering in a neotropical gallery forest

41 páginas, 6 tablas, 2 figuras[EN] In this study, we investigated the spatial distribution of an earthworm community together with the heterogeneity of selected soil properties in a gallery forest (GF) of the Colombian “Llanos”. We performed fine-scale spatial variability by intensively sampling 100 points distributed in the nodes of a regular grid with 5 m inter-sample distance. Non-parametric statistics were used and included SADIE analysis and partial Mantel test, in addition to geostatistics (semi-variograms) and correlogram computation. Our results indicated that the spatial distribution of earthworms was characterized by areas of presence (patches) and absence (gaps), although the general pattern was random at the scale of this study (30 m, respectively. Partial Mantel test revealed specific significant relationships between soil variables and some species. The earthworm community of the GF displayed a random structure in a spatially clumped soil environment, and our results suggested that spatial distribution observed for some species could be the result of preferential selection of soil environmental factors. In other words, soil heterogeneity contributed to the formation of population patches for some earthworm species. The variability of suitable sites (resource availability patchiness) exerted an influence in the spatial distribution of earthworms at the scale used in this study, and we identified the spatial scale at which both environmental heterogeneity could influence and express earthworm impact on soil properties.Local names for tree species of the gallery forest are those specifically used in the Carimagua region, and field assistants Jose García, Salvador Rojas and Guillermo Murcia are deeply appreciated for their help in field sampling and sharing their knowledge. CIAT and IRD provided financial and logistic support during field work. We would like to thank research assistant Jaumer Ricaute for root analysis at CIAT lab. Thanks are extended to Jean-Pierre Rossi (INRA) for fruitful discussions on spatial statistics tools, and Michael S. Rosenberg (Arizona State University) for availability and permission to use PASSaGE software. Finally, the useful comments of two anonymous referees and assigned editor are greatly acknowledged.Peer reviewe

M2-Polarized tumor-associated macrophages are associated with poor prognoses resulting from accelerated lymphangiogenesis in lung adenocarcinoma

OBJECTIVES: Tumor-associated macrophages have been implicated in promoting tumor growth, progression and metastasis. However, the activated phenotype (M1 or M2) of tumor-associated macrophages remains unknown in solid tumors. Therefore, this study examined the density and prognostic significance of M2-polarized tumor-associated macrophages in lung adenocarcinoma. METHODS: Tumor specimens from 65 lung adenocarcinoma patients were assessed by ELISA for Th1/Th2 cytokine concentrations. The activated phenotype (M1 or M2) of tumor-associated macrophages was determined utilizing immunofluorescence staining. Additionally, to evaluate lymphangiogenesis, peritumoral lymphatic microvessel density was measured using D2-40. The correlation between tumor-associated macrophage subtype and overall patient survival was analyzed using the Kaplan-Meier method and compared using the log-rank test. RESULTS: A shift toward Th2 cytokine expression was detected within lung adenocarcinoma microenvironments. Approximately 79.71±16.27% of tumor-associated macrophages were M2 polarized; the remaining 20.35±5.31% were M1 polarized. The infiltration of M2-polarized macrophages was significantly associated with P-TNM staging and lymph node metastasis. The peritumoral lymphatic microvessel density was significantly higher in the high M2-polarized tumor-associated macrophage group than in the low M2-polarized tumor-associated macrophage group. A significant difference in overall patient survival was detected not only between patients with tumors with high and low macrophage counts but also between patients with tumors with high and low counts of M2-polarized macrophages. CONCLUSION: Tumor-associated macrophages in lung adenocarcinoma have an M2-polarized subtype and are associated with poor prognoses, perhaps resulting from accelerated lymphangiogenesis and lymph node metastasis