Negative Pressures and the First Water Siphon Taller than 10.33 Meters

A siphon is a device that is used to drain a container, with water rising inside a hose in the form of an inverted U and then going down towards a discharge point placed below the initial water level. The siphon is the first of a number of inventions of the ancients documented about 2.000 years ago by Hero of Alexandria in his treatise Pneumatics, and although the explanation given by Hero was essentially correct, there is nowadays a controversy about the underlying mechanism that explains the working of this device. Discussions concerning the physics of a siphon usually refer to concepts like absolute negative pressures, the strength of liquid’s cohesion and the possibility of a siphon working in vacuum or in the presence of bubbles. Torricelli understood the working principle of the barometer and the impossibility of pumping water out of wells deeper than 10.33 m. Following Torricelli’s ideas it would also not be possible to build a siphon that drives pure water to ascend higher than 10.33 m. In this work, we report the first siphon that drives water (with surfactant) to ascend higher than the Torricellian limit. Motivated by the rising of sap in trees, we built a 15.4 m siphon that shows that absolute negative pressures are not prohibited, that cohesion plays an important role in transmitting forces through a fluid, and that surfactants can help to the transport of water in a metastable regime of negative pressures.     

Characterization of Bacterial Communities in Selected Smokeless Tobacco Products Using 16S rDNA Analysis

The bacterial communities present in smokeless tobacco (ST) products have not previously reported. In this study, we used Next Generation Sequencing to study the bacteria present in U.S.-made dry snuff, moist snuff and Sudanese toombak. Sample diversity and taxonomic abundances were investigated in these products. A total of 33 bacterial families from four phyla, Actinobacteria, Firmicutes, Proteobacteria and Bacteroidetes, were identified. U.S.-produced dry snuff products contained a diverse distribution of all four phyla. Moist snuff products were dominated by Firmicutes. Toombak samples contained mainly Actinobacteria and Firmicutes (Aerococcaceae, Enterococcaceae, and Staphylococcaceae). The program PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) was used to impute the prevalence of genes encoding selected bacterial toxins, antibiotic resistance genes and other pro-inflammatory molecules. PICRUSt also predicted the presence of specific nitrate reductase genes, whose products can contribute to the formation of carcinogenic nitrosamines. Characterization of microbial community abundances and their associated genomes gives us an indication of the presence or absence of pathways of interest and can be used as a foundation for further investigation into the unique microbiological and chemical environments of smokeless tobacco products.     

Patterns of Genetic Variability in Island Populations of the Cane Toad (Rhinella marina) from the Mouth of the Amazon

The Amazonian coast has several unique geological characteristics resulting from the interaction between drainage pattern of the Amazon River and the Atlantic Ocean. It is one of the most extensive and sedimentologically dynamic regions of the world, with a large number of continental islands mostly formed less than 10,000 years ago. The natural distribution of the cane toad (Rhinella marina), one of the world’s most successful invasive species, in this complex Amazonian system provides an intriguing model for the investigation of the effects of isolation or the combined effects of isolation and habitat dynamic changes on patterns of genetic variability and population differentiation. We used nine fast-evolving microsatellite loci to contrast patterns of genetic variability in six coastal (three mainlands and three islands) populations of the cane toad near the mouth of the Amazon River. Results from Bayesian multilocus clustering approach and Discriminant Analyses of Principal Component were congruent in showing that each island population was genetically differentiated from the mainland populations. All F_ST values obtained from all pairwise comparisons were significant, ranging from 0.048 to 0.186. Estimates of both recent and historical gene flow were not significantly different from zero across all population pairs, except the two mainland populations inhabiting continuous habitats. Patterns of population differentiation, with a high level of population substructure and absence/restricted gene flow, suggested that island populations of R. marina are likely isolated since the Holocene sea-level rise. However, considering the similar levels of genetic variability found in both island and mainland populations, it is reliable to assume that they were also isolated for longer periods. Given the genetic uniqueness of each cane toad population, together with the high natural vulnerability of the coastal regions and intense human pressures, we suggest that these populations should be treated as discrete units for conservation management purposes.     

Early Indicators of Fatal Leptospirosis during the 2010 Epidemic in Puerto Rico

Background

Leptospirosis is a potentially fatal bacterial zoonosis that is endemic throughout the tropics and may be misdiagnosed as dengue. Delayed hospital admission of leptospirosis patients is associated with increased mortality.

Methodology/Principal Findings

During a concurrent dengue/leptospirosis epidemic in Puerto Rico in 2010, suspected dengue patients that tested dengue-negative were tested for leptospirosis. Fatal and non-fatal hospitalized leptospirosis patients were matched 1:1–3 by age. Records from all medical visits were evaluated for factors associated with fatal outcome. Among 175 leptospirosis patients identified (4.7 per 100,000 residents), 26 (15%) were fatal. Most patients were older males and had illness onset during the rainy season. Fatal case patients first sought medical care earlier than non-fatal control patients (2.5 vs. 5 days post-illness onset [DPO], p < 0.01), but less frequently first sought care at a hospital (52.4% vs. 92.2%, p < 0.01). Although fatal cases were more often diagnosed with leptospirosis at first medical visit (43.9% vs. 9.6%, p = 0.01), they were admitted to the hospital no earlier than non-fatal controls (4.5 vs. 6 DPO, p = 0.31). Cases less often developed fever (p = 0.03), but more often developed jaundice, edema, leg pain, hemoptysis, and had a seizure (p ≤ 0.03). Multivariable analysis of laboratory values from first medical visit associated with fatal outcome included increased white blood cell (WBC) count with increased creatinine (p = 0.001), and decreased bicarbonate with either increased WBC count, increased creatinine, or decreased platelet count (p < 0.001).

Conclusions/Significance

Patients with fatal leptospirosis sought care earlier, but were not admitted for care any earlier than non-fatal patients. Combinations of routine laboratory values predictive of fatal outcome should be considered in admission decision-making for patients with suspected leptospirosis.     

Effect of different levels of concentrate on ruminal microorganisms and rumen fermentation in Nellore steers

The aim of this study was to investigate the effect of different dietary levels of concentrate on feed intake, digestibility, ruminal fermentation and microbial population in steers. Eight Nellore steers fitted with ruminal cannulas were used in a double 4 × 4 Latin square design experiment. The dietary treatments consist of four different proportions of concentrate to roughage: 30:70, 40:60, 60:40 and 80:20% in the dry matter, resulting in Diets 30, 40, 60 and 80, respectively. The roughage was corn silage, and the concentrate was composed of corn, soybean meal and urea. Apparent digestibility of organic matter and crude protein showed a linear association with concentrate proportion (p = 0.01), but the increased concentrate levels did not affect the digestibility of fibre. The lowest ruminal pH-values were observed in animals fed with Diet 80, remaining below pH 6.0 from 6 h after feeding, while in the other diets, the ruminal pH was below 6.0 not before 12 h after feeding. After feeding Diet 80, the ammonia concentration in the rumen was significantly the highest. Higher dietary concentrate levels resulted in a linear increase of propionic acid concentrations, a linear reduction of the ratio acetic acid to propionic acid (p < 0.01) and a linear increased synthesis of microbial nitrogen (p < 0.001). The predicted production of methane was lower in diets with greater amounts of concentrate (p = 0.032). The population of methanogens, R. flavefaciens and R. albus decreased with higher concentrate levels, while the population of S. ruminantium increased (p < 0.05). The results indicate that greater amounts of concentrate do not decrease ruminal pH-values as much as expected and inhibit some cellulolytic bacteria without impairing the dry matter intake and fibre digestibility in Nellore steers.     

Blimp-1-Dependent IL-10 Production by Tr1 Cells Regulates TNF-Mediated Tissue Pathology

Tumor necrosis factor (TNF) is critical for controlling many intracellular infections, but can also contribute to inflammation. It can promote the destruction of important cell populations and trigger dramatic tissue remodeling following establishment of chronic disease. Therefore, a better understanding of TNF regulation is needed to allow pathogen control without causing or exacerbating disease. IL-10 is an important regulatory cytokine with broad activities, including the suppression of inflammation. IL-10 is produced by different immune cells; however, its regulation and function appears to be cell-specific and context-dependent. Recently, IL-10 produced by Th1 (Tr1) cells was shown to protect host tissues from inflammation induced following infection. Here, we identify a novel pathway of TNF regulation by IL-10 from Tr1 cells during parasitic infection. We report elevated Blimp-1 mRNA levels in CD4⁺ T cells from visceral leishmaniasis (VL) patients, and demonstrate IL-12 was essential for Blimp-1 expression and Tr1 cell development in experimental VL. Critically, we show Blimp-1-dependent IL-10 production by Tr1 cells prevents tissue damage caused by IFNγ-dependent TNF production. Therefore, we identify Blimp-1-dependent IL-10 produced by Tr1 cells as a key regulator of TNF-mediated pathology and identify Tr1 cells as potential therapeutic tools to control inflammation.     

Elucidating the genetic basis of biomass accumulation and radiation use efficiency in spring wheat and its role in yield potential

One of the major challenges for plant scientists is increasing wheat (Triticum aestivum) yield potential (YP). A significant bottleneck for increasing YP is achieving increased biomass through optimization of radiation use efficiency (RUE) along the crop cycle. Exotic material such as landraces and synthetic wheat has been incorporated into breeding programmes in an attempt to alleviate this; however, their contribution to YP is still unclear. To understand the genetic basis of biomass accumulation and RUE, we applied genome‐wide association study (GWAS) to a panel of 150 elite spring wheat genotypes including many landrace and synthetically derived lines. The panel was evaluated for 31 traits over 2 years under optimal growing conditions and genotyped using the 35K wheat breeders array. Marker‐trait association identified 94 SNPs significantly associated with yield, agronomic and phenology‐related traits along with RUE and final biomass (BM_PM) at various growth stages that explained 7%–17% of phenotypic variation. Common SNP markers were identified for grain yield, BM_PM and RUE on chromosomes 5A and 7A. Additionally, landrace and synthetic derivative lines showed higher thousand grain weight (TGW), BM_PM and RUE but lower grain number (GM2) and harvest index (HI). Our work demonstrates the use of exotic material as a valuable resource to increase YP. It also provides markers for use in marker‐assisted breeding to systematically increase BM_PM, RUE and TGW and avoid the TGW/GM2 and BM_PM/HI trade‐off. Thus, achieving greater genetic gains in elite germplasm while also highlighting genomic regions and candidate genes for further study.     

Serum ferritin as a candidate diagnostic biomarker of polycystic ovarian syndrome: a meta-analysis

Objective: In this study, we investigated about the potential of serum ferritin as a complementary diagnostic biomarker of polycystic ovarian syndrome (PCOS) by performing a meta-analysis of existing literature.

Materials and methods: Eleven studies written in English were retrieved up to 30 June 2018. Data were extracted from the selected studies by two of the authors and was subjected to statistical analysis. Levels of serum ferritin were compared between women with PCOS and controls using the standardized mean difference (SMD) and 95% confidence interval (CI). Subgroup analysis was also performed and stratified by ethnicity (Asians versus Caucasians).

Results: Overall post-outlier outcomes indicated that elevated serum ferritin is strongly associated with PCOS (SMD: 0.52; 95% CI: 0.40–0.64; P^A?=?10^?5). Subgroup analysis by ethnicity showed no significant difference between Asian and Caucasian population. Post-outlier receiving operations characteristics curve were plotted and showed that values for serum ferritin showed good potential in discriminating patients with and without PCOS (AUC?=?0.827, p?=?0.006).

Conclusion: Our findings suggest that high serum ferritin level is significantly associated with PCOS and its potential as a biomarker is evident in its high diagnostic accuracy. However, additional studies are needed to confirm our claims.     

Antileishmanial activity and cytotoxicity of ent-beyerene diterpenoids

We describe the in vitro activity of two natural isomeric ent-beyerene diterpenes, several derivatives and synthetic intermediates. Beyerenols 1 and 2 showed EC₅₀ of 4.6?±?9.4 and 5.3?±?9.4?μg/mL against amastigotes of L. (V) brazilensis, with SI of 5.1 and 7.7, respectively. Beyerenol 1 was synthesized from stevioside. In vivo experiments with bereyenols showed cure in 50% of hamsters infected with L. (V) brazilensis topically applied as Cream I (beyerenol 1, 0.81%, w/w) and Cream III (beyerenol 2, 1.96%, w/w). These results suggest that beyerenols are potential candidates for cutaneous leishmaniasis chemotherapy by topical application. In vitro assays of amastigotes of L. (V) brazilensis showed EC₅₀ of 1.1?±?0.1 and 1.3?±?0.04?μg/mL, with SI of 3.1 and 3.5 for hydrazone intermediates 10 and 11, respectively.