Assessing Dietary Branched-Chain Amino Acids to Achieve Linear Programming Goals through Model Extrapolation and Empirical Research

Renewed interest, especially in the United States, has sparked in assessing branched-chain amino acid interactions in practical diets for broilers. Indeed, as L-valine enters formulation bird nitrogen excesses are reduced as diet protein falls to the new first limiting amino acid (e.g., isoleucine, arginine, or tryptophan). For a United States based example, the result is less oilseeds and more gains, which typically result in increased inclusions in corn or corn by-products, coupled with a concomitant increase in dietary leucine. The proceedings outline the foundations of the branched-chain amino acid early research, antagonism studies, and a meta-analysis conducted on publications with Cobb and Ross birds from 2000 to present. Results indicate that branched-chain amino acid interactions can occur in broilers fed on practical diets, and that responses vary by strain

The taxonomy and phylogeny of the Cyrtodactylus brevipalmatus group (Squamata: Gekkonidae) with emphasis on C. interdigitalis and C. ngati

Abstract Convergent morphological specializations for an arboreal lifestyle in most species of the Cyrtodactylus brevipalmatus group have been a confounding factor for establishing a stable taxonomy among its species. Recent references to C. interdigitalis from throughout Thailand and Laos were made without comparisons to the type material from Tham Yai Nam Nao, Nam Nao National Park, Phetchabun Province, Thailand, but instead, were based on general morphological similarity and distribution. The taxonomy of C. interdigitalis is stabilized here by comparing the paratypes to other specimens from Thailand and Laos and recovering their phylogenetic relationships based on newly acquired genetic data, including those from the type locality. The phylogeny recovered all specimens outside the type locality to be either C. ngati from Vietnam or new species closely related to C. ngati. Cyrtodactylus interdigitalis is shown here to be a range-restricted upland endemic on the Phetchabun massif of northern Thailand. The phylogeny also indicates that C. ngati extends hundreds of kilometers farther south into northern Thailand and central Laos. We hypothesize that the significant morphological divergence in body shape of the types of C. ngati, compared to that of the Lao and Thai populations, may be due to local adaptions for utilizing karst (C. ngati) rather than vegetation (Lao and Thai populations). Additionally, phylogenetic and multivariate analyses identified a potentially new species from Phu Hin Rong Kla National Park, Phitsanulok Province, in northern Thailand and another from the Khlong Naka Wildlife Sanctuary, Ranong Province, in southern Thailand. A series of newly examined specimens from Kaeng Krachan National Park, Phetchaburi Province, Thailand represents a possible ~82 km range extension to the southeast of C. rukhadeva. This research continues to underscore the high diversity of range-restricted upland endemics in Thailand and the importance of examining type material (if possible) in the context of a phylogeny so as to construct proper taxonomies that reveal, rather than obscure, diversity

Population density, water supply, and the risk of dengue fever in Vietnam: cohort study and spatial analysis.

BACKGROUND: Aedes aegypti, the major vector of dengue viruses, often breeds in water storage containers used by households without tap water supply, and occurs in high numbers even in dense urban areas. We analysed the interaction between human population density and lack of tap water as a cause of dengue fever outbreaks with the aim of identifying geographic areas at highest risk. METHODS AND FINDINGS: We conducted an individual-level cohort study in a population of 75,000 geo-referenced households in Vietnam over the course of two epidemics, on the basis of dengue hospital admissions (n = 3,013). We applied space-time scan statistics and mathematical models to confirm the findings. We identified a surprisingly narrow range of critical human population densities between around 3,000 to 7,000 people/km² prone to dengue outbreaks. In the study area, this population density was typical of villages and some peri-urban areas. Scan statistics showed that areas with a high population density or adequate water supply did not experience severe outbreaks. The risk of dengue was higher in rural than in urban areas, largely explained by lack of piped water supply, and in human population densities more often falling within the critical range. Mathematical modeling suggests that simple assumptions regarding area-level vector/host ratios may explain the occurrence of outbreaks. CONCLUSIONS: Rural areas may contribute at least as much to the dissemination of dengue fever as cities. Improving water supply and vector control in areas with a human population density critical for dengue transmission could increase the efficiency of control efforts. Please see later in the article for the Editors' Summary

Assessment of Blood Hemodynamics by USPIO-Induced R1 Changes in MRI of Murine Colon Carcinoma

The objective of this study is to assess whether ultrasmall superparamagnetic iron oxide (USPIO)-induced changes of the water proton longitudinal relaxation rate (R1) provide a means to assess blood hemodynamics of tumors. Two types of murine colon tumors (C26a and C38) were investigated prior to and following administration of USPIO blood-pool contrast agent with fast R1 measurements. In a subpopulation of mice, R1 was measured following administration of hydralazine, a well-known blood hemodynamic modifier. USPIO-induced R1 increase in C38 tumors (ΔR1 = 0.072 ± 0.0081 s−1) was significantly larger than in C26a tumors (ΔR1 = 0.032 ± 0.0018 s−1, N = 9, t test, P < 0.001). This was in agreement with the immunohistochemical data that showed higher values of relative vascular area (RVA) in C38 tumors than in C26a tumors (RVA = 0.059 ± 0.015 vs. 0.020 ± 0.011; P < 0.05). Following administration of hydralazine, a decrease in R1 value was observed. This was consistent with the vasoconstriction induced by the steal effect mechanism. In conclusion, R1 changes induced by USPIO are sensitive to tumor vascular morphology and to blood hemodynamics. Thus, R1 measurements following USPIO administration can give novel insight into the effects of blood hemodynamic modifiers, non-invasively and with a high temporal resolution

Survey of childhood empyema in Asia: Implications for detecting the unmeasured burden of culture-negative bacterial disease

<p>Abstract</p> <p>Background</p> <p>Parapneumonic empyema continues to be a disease of significant morbidity and mortality among children despite recent advances in medical management. To date, only a limited number of studies have assessed the burden of empyema in Asia.</p> <p>Methods</p> <p>We surveyed medical records of four representative large pediatric hospitals in China, Korea, Taiwan and Vietnam using <it>ICD</it>-10 diagnostic codes to identify children <16 years of age hospitalized with empyema or pleural effusion from 1995 to 2005. We also accessed microbiology records of cultured empyema and pleural effusion specimens to describe the trends in the epidemiology and microbiology of empyema.</p> <p>Results</p> <p>During the study period, we identified 1,379 children diagnosed with empyema or pleural effusion (China, n = 461; Korea, n = 134; Taiwan, n = 119; Vietnam, n = 665). Diagnoses of pleural effusion (n = 1,074) were 3.5 times more common than of empyema (n = 305), although the relative proportions of empyema and pleural effusion noted in hospital records varied widely between the four sites, most likely because of marked differences in coding practices. Although pleural effusions were reported more often than empyema, children with empyema were more likely to have a cultured pathogen. In addition, we found that median age and gender distribution of children with these conditions were similar across the four countries. Among 1,379 empyema and pleural effusion specimens, 401 (29%) were culture positive. <it>Staphylococcus aureus </it>(n = 126) was the most common organism isolated, followed by <it>Streptococcus pneumoniae </it>(n = 83), <it>Pseudomonas aeruginosa </it>(n = 37) and <it>Klebsiella </it>(n = 35) and <it>Acinetobacter </it>species (n = 34).</p> <p>Conclusion</p> <p>The age and gender distribution of empyema and pleural effusion in children in these countries are similar to the US and Western Europe. <it>S. pneumoniae </it>was the second leading bacterial cause of empyema and pleural effusion among Asian children. The high proportion of culture-negative specimens among patients with pleural effusion or empyema suggests that culture may not be a sufficiently sensitive diagnostic method to determine etiology in the majority of cases. Future prospective studies in different countries would benefit from standardized case definitions and coding practices for empyema. In addition, more sensitive diagnostic methods would improve detection of pathogens and could result in better prevention, treatment and outcomes of this severe disease.</p

Soft Substrates Promote Homogeneous Self-Renewal of Embryonic Stem Cells via Downregulating Cell-Matrix Tractions

Maintaining undifferentiated mouse embryonic stem cell (mESC) culture has been a major challenge as mESCs cultured in Leukemia Inhibitory Factor (LIF) conditions exhibit spontaneous differentiation, fluctuating expression of pluripotency genes, and genes of specialized cells. Here we show that, in sharp contrast to the mESCs seeded on the conventional rigid substrates, the mESCs cultured on the soft substrates that match the intrinsic stiffness of the mESCs and in the absence of exogenous LIF for 5 days, surprisingly still generated homogeneous undifferentiated colonies, maintained high levels of Oct3/4, Nanog, and Alkaline Phosphatase (AP) activities, and formed embryoid bodies and teratomas efficiently. A different line of mESCs, cultured on the soft substrates without exogenous LIF, maintained the capacity of generating homogeneous undifferentiated colonies with relatively high levels of Oct3/4 and AP activities, up to at least 15 passages, suggesting that this soft substrate approach applies to long term culture of different mESC lines. mESC colonies on these soft substrates without LIF generated low cell-matrix tractions and low stiffness. Both tractions and stiffness of the colonies increased with substrate stiffness, accompanied by downregulation of Oct3/4 expression. Our findings demonstrate that mESC self-renewal and pluripotency can be maintained homogeneously on soft substrates via the biophysical mechanism of facilitating generation of low cell-matrix tractions

A mechanically active heterotypic E-cadherin/N-cadherin adhesion enables fibroblasts to drive cancer cell invasion

Cancer-associated fibroblasts (CAFs) promote tumour invasion and metastasis. We show that CAFs exert a physical force on cancer cells that enables their collective invasion. Force transmission is mediated by a heterophilic adhesion involving N-cadherin at the CAF membrane and E-cadherin at the cancer cell membrane. This adhesion is mechanically active; when subjected to force it triggers β-catenin recruitment and adhesion reinforcement dependent on α-catenin/vinculin interaction. Impairment of E-cadherin/N-cadherin adhesion abrogates the ability of CAFs to guide collective cell migration and blocks cancer cell invasion. N-cadherin also mediates repolarization of the CAFs away from the cancer cells. In parallel, nectins and afadin are recruited to the cancer cell/CAF interface and CAF repolarization is afadin dependent. Heterotypic junctions between CAFs and cancer cells are observed in patient-derived material. Together, our findings show that a mechanically active heterophilic adhesion between CAFs and cancer cells enables cooperative tumour invasion

Characterization of Coastal Urban Watershed Bacterial Communities Leads to Alternative Community-Based Indicators

BACKGROUND: Microbial communities in aquatic environments are spatially and temporally dynamic due to environmental fluctuations and varied external input sources. A large percentage of the urban watersheds in the United States are affected by fecal pollution, including human pathogens, thus warranting comprehensive monitoring. METHODOLOGY/PRINCIPAL FINDINGS: Using a high-density microarray (PhyloChip), we examined water column bacterial community DNA extracted from two connecting urban watersheds, elucidating variable and stable bacterial subpopulations over a 3-day period and community composition profiles that were distinct to fecal and non-fecal sources. Two approaches were used for indication of fecal influence. The first approach utilized similarity of 503 operational taxonomic units (OTUs) common to all fecal samples analyzed in this study with the watershed samples as an index of fecal pollution. A majority of the 503 OTUs were found in the phyla Firmicutes, Proteobacteria, Bacteroidetes, and Actinobacteria. The second approach incorporated relative richness of 4 bacterial classes (Bacilli, Bacteroidetes, Clostridia and alpha-proteobacteria) found to have the highest variance in fecal and non-fecal samples. The ratio of these 4 classes (BBC:A) from the watershed samples demonstrated a trend where bacterial communities from gut and sewage sources had higher ratios than from sources not impacted by fecal material. This trend was also observed in the 124 bacterial communities from previously published and unpublished sequencing or PhyloChip- analyzed studies. CONCLUSIONS/SIGNIFICANCE: This study provided a detailed characterization of bacterial community variability during dry weather across a 3-day period in two urban watersheds. The comparative analysis of watershed community composition resulted in alternative community-based indicators that could be useful for assessing ecosystem health

Environmental effects of ozone depletion, UV radiation and interactions with climate change : UNEP Environmental Effects Assessment Panel, update 2017

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