Biliary tract cancer or extrahepatic cholangiocarcinoma (ECCA) represents the sixth commonest cause of cancer in the gastrointestinal tract in western countries. We aimed to characterize the ...microbiota and its predicted associated functions in the biliary tract of ECCA and benign biliary pathology (BBP). Samples were taken from 100 patients with ECCA and 100 patients with BBP by endoscopic cholangio-pancreatography for DNA extraction. Ten patients with ECCA and ten with BBP were selected for microbiota studies using the V4-16S rRNA gene and sequenced in Illumina platform. Microbiota analyses included sample-to-sample distance metrics, ordination/clustering and prediction of functions. Presence of Nesterenkonia sp. and Helicobacter pylori cagA and vacA genes were tested in the 100 ECCA and 100 BBP samples. Phylum Proteobacteria dominated all samples (60.4% average). Ordination multicomponent analyses showed significant microbiota separation between ECCA and BBP (p 0.010). Analyses of 4002 operational taxonomic units with presence variation in at least one category probed a separation of ECCA from BBP. Among these, Nesterenkonia decreased, whereas Methylophilaceae, Fusobacterium, Prevotella, Actinomyces, Novosphingobium and H. pylori increased in ECCA. Predicted associated functions showed increased abundance of H. pylori virulence genes in ECCA. cagA and vacA genes were confirmed by PCR in ECCA and BBP samples. This is the first microbiota report in ECCA and BBP to show significant changes in microbial composition. Bacterial species unusual for human flora were found: Methylophilaceae and Nesterenkonia are reported in hypersaline soils, and Mesorhizobium is a nitrogen-fixing bacterium. Enrichment of virulence genes confirms previous studies suggesting that H. pylori might be associated with ECCA.
This article analyzes the determinants of protest participation in Latin America. Whereas most research emphasizes grievances over resources, or vice versa, this article explains protest ...participation as the interaction between individuals' state‐targeted grievances and material resources. I argue that grievances and availability of material resources interact and fuel protest among individuals whose income falls close to the middle of the income distribution, but not among the poor or the rich. Whereas the scarcity of resources mitigates the politicization of grievances among the poor, the relative abundance of resources and alternative channels of political influence produces the same effect among the rich. Analysis of survey data from Latin American democracies provides strong support for these arguments.
Summary
Approximately half of individuals with hypophosphatasemia (low levels of serum alkaline phosphatase) have hypophosphatasia, a rare genetic disease in which patients may have stress fractures, ...bone and joint pain, or premature tooth loss. We developed a predictive model based on specific biomarkers of this disease to better diagnose this condition.
Introduction
Hypophosphatasemia is a condition in which low levels of alkaline phosphatase (ALP) are detected in the serum. Some individuals presenting with this condition may have a rare genetic disease called
hypophosphatasia
(HPP), which involves mineralization of the bone and teeth. Lack of awareness of HPP and its nonspecific symptoms make this genetic disease difficult to diagnose. We developed a predictive model based on biomarkers of HPP such as ALP and pyridoxal 5′-phosphate (PLP), because clinical manifestations sometimes are not recognized as symptoms of HPP.
Methods
We assessed 325,000 ALP results between 2010 and 2015 to identify individuals suspected of having HPP. We performed univariate and multivariate analyses to characterize the relationship between hypophosphatasemia and HPP. Using several machine learning algorithms, we developed several models based on biomarkers and compared their performance to determine the best model.
Results
The final cohort included 45 patients who underwent a genetic test. Half (23 patients) showed a mutation of the ALPL gene that encodes the tissue-nonspecific ALP enzyme. ALP (odds ratio OR 0.61, 95% confidence interval CI 0.3–0.8,
p
= 0.01) and PLP (OR 1.06, 95% CI 1.01–1.15,
p
= 0.04) were the only variables significantly associated with the presence of HPP. Support vector machines and logistic regression were the machine learning algorithms that provided the best predictive models in terms of classification (area under the curve 0.936 and 0.844, respectively).
Conclusions
Given the high probability of a misdiagnosis, its nonspecific symptoms, and a lack of awareness of serum ALP levels, it is difficult to make a clinical diagnosis of HPP. Predictive models based on biomarkers are necessary to achieve a proper diagnosis. Our proposed machine learning approaches achieved reasonable performance compared to traditional statistical methods used in biomedicine, increasing the likelihood of properly diagnosing such a rare disease as HPP.
Maize demand in Sub-Saharan Africa is expected to increase 2.3 times during the next 30 years driven by demographic and dietary changes. Over the past two decades, the area cropped with maize has ...expanded by 17 million hectares in the region, with limited yield increase. Following this trend could potentially result in further maize cropland expansion and the need for imports to satisfy domestic demand. Here, we use data collected from 14,773 smallholder fields in the region to identify agronomic practices that can improve farm yield gains. We find that agronomic practices related to cultivar selection, and nutrient, pest, and crop management can double on-farm yields and provide an additional 82 million tons of maize within current cropped area. Research and development investments should be oriented towards agricultural practices with proven capacity to raise maize yields in the region.
•Thermal properties of mortars incorporating Phase Change Materials are analysed.•A good balance between thermal diffusivity and effusivity is essential.•The best thermal properties are obtained ...using silica aggregates and antifoaming.•The amount of PCM reduces conductivity and diffusivity but effusivity is invariant.•The mortar design has to focus on diffusivity to reach proper heat diffusion rates.
This work presents an experimental research on the thermal properties of novel cementitious mortars incorporating microencapsulated Phase Change Materials intended to be used as the innermost layer in a precast radiant building component actively controlled by an integrated hydronic system.
The characterization was developed in two steps: the first one focused on the effects of different fine aggregates and admixtures for a fixed PCM content and the second one on the effect of changing the amount of PCM. Results show that using silica aggregates and antifoaming admixture outperform the other options, producing mortars with statistically significant higher thermal conductivities, diffusivities and effusivities. Besides, increasing the amount of PCM significantly reduces conductivity and diffusivity, but the effusivity is practically invariant. This suggests that the mortar design has to be defined by predominantly focusing on diffusivity, in order to achieve appropriate heat penetration rates and activation times for an efficient system operation.
Cellulosic pulp from sugar beet leaves was fractionated and assessed on its interfacial properties. After pressing leaves to express the juice, the press cake was washed at alkaline pH (pH 9) to ...remove residual protein, dried, milled and air classified. The obtained cellulosic particles mainly consisted of insoluble dietary fibre (77.8% w/w) with remaining proteins (6.3% w/w) and exhibited considerable interfacial activity. The protein impurities contribute to the surface charge of the particles and provide surface activity, leading to spontaneous diffusion of the particles during the interfacial tension analysis; whereas the particle adsorption kinetics were characteristic of soft particles or Pickering emulsifiers. The interfacial rheology measurements showed abnormal behaviour and unusual drop shape upon deformation, hindering interpretation of the analysis but still suggesting a rigid interface with strong physical particle-particle interactions. Stable oil-in-water emulsions were produced using cellulosic particles, and despite phase separation, the emulsions were stable against coalescence. The results suggested that mostly fine particles (0.04–1.0 μm) were responsible for the interfacial stabilisation, given the small oil droplets obtained (2–5 μm); whereas larger particles (>10 μm) created a network in the continuous phase, which was responsible for the emulsion phase separation. It was concluded that the cellulosic particles had a soft nature and suitable shape to produce stable Pickering emulsions, which can be used as food-grade particles for food and pharma applications.
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•Leaf cellulosic particles behave like soft particles at the oil-water interface.•Protein impurities provide surface activity to the particles.•Solid nature of particles responsible for interfacial behaviour upon deformation.•Finest particles stabilise the interface as Pickering emulsifiers.•Large particles aggregate, immobilising oil droplets and leading to creaming.
In order to determine the potential effects of contaminants in juveniles of East Pacific green turtle, Chelonia mydas, captured alive, circulating trace metal and organochlorine pesticide ...concentrations were correlated with body condition, antioxidant enzyme activities and lipid peroxidation levels. Turtles were sampled in Punta Abreojos (PAO) and Bahía Magdalena (BMA). Turtles from PAO showed higher silicon and cadmium concentrations, but lower α-hexachlorocyclohexane, γ-hexachlorocyclohexane, hexachlorobenzene and aldrin concentrations than individuals from BMA. In BMA cadmium concentration decreased as the standard carapace length of the turtles increased. In PAO concentrations of α-hexachlorocyclohexane, heptachlor and hexachlorobenzene were positively correlated with the weight of the individuals. Lipid peroxidation levels were positively correlated with cadmium concentrations. In turtles captured in PAO, enzymatic antioxidant activities correlated mostly with pesticide concentrations, while in individuals from BMA enzyme activities were correlated with trace element concentrations. Correlations between antioxidant enzyme activities and concentration of xenobiotics suggest physiological sensitivity of East Pacific green turtles to chemicals. Regional differences found could be influenced by habitat conditions such as currents, upwellings (PAO) and agricultural activities (BMA). We suggest that, combined, circulating contaminant concentrations, lipid peroxidation levels and antioxidant enzyme activities in sea turtles could be used as biomarkers of the habitat conditions.
I am very pleased to participate in this dialogue on the effect of collective protest on social spending in Latin America, which initiated when the editors of LAPS invited me to review the research ...note titled “Organized Labor Strikes and Social Spending in Latin America: The Synchronizing Effect of Mass Protest.” Dongkyu Kim, Mi-son Kim, and Cesar Villegas engage with my paper, published in
Comparative Political Studies
(Zarate-Tenorio 2014), which analyzes the effects of organized labor strikes and mass protests on social security and welfare, health and education spending in Latin America, 1970–2007.
Clostridioides difficile (C. difficile) is widely distributed in the intestinal tract of humans, animals, and in the environment. It is the most common cause of diarrhea associated with the use of ...antimicrobials in humans and among the most common healthcare-associated infections worldwide. Its pathogenesis is mainly due to the production of toxin A (TcdA), toxin B (TcdB), and a binary toxin (CDT), whose genetic variants may be associated with disease severity. We studied genetic diversity in 39 C. difficile isolates from adults and children attended at two Mexican hospitals, using different gene and genome typing methods and investigated their association with in vitro expression of toxins. Whole-genome sequencing in 39 toxigenic C. difficile isolates were used for multilocus sequence typing, tcdA, and tcdB typing sequence type, and phylogenetic analysis. Strains were grown in broth media, and expression of toxin genes was measured by real-time PCR and cytotoxicity in cell-culture assays. Clustering of strains by genome-wide phylogeny matched clade classification, forming different subclusters within each clade. The toxin profile tcdA+/tcdB+/cdt+ and clade 2/ST1 were the most prevalent among isolates from children and adults. Isolates presented two TcdA and three TcdB subtypes, of which TcdA2 and TcdB2 were more prevalent. Prevalent clades and toxin subtypes in strains from children differed from those in adult strains. Toxin gene expression or cytotoxicity was not associated with genotyping or toxin subtypes. In conclusion, genomic and phenotypic analysis shows high diversity among C. difficile isolates from patients with healthcare-associated diarrhea.IMPORTANCEClostridioides difficile is a toxin-producing bacterial pathogen recognized as the most common cause of diarrhea acquired primarily in healthcare settings. This bacterial species is diverse; its global population has been divided into five different clades using multilocus sequence typing, and strains may express different toxin subtypes that may be related to the clades and, importantly, to the severity and progression of disease. Genotyping of children strains differed from adults suggesting toxins might present a reduced toxicity. We studied extensively cytotoxicity, expression of toxins, whole genome phylogeny, and toxin typing in clinical C. difficile isolates. Most isolates presented a tcdA+/ tcdB+/cdt+ pattern, with high diversity in cytotoxicity and clade 2/ST1 was the most prevalent. However, they all had the same TcdA2/TcdB2 toxin subtype. Advances in genomics and bioinformatics tools offer the opportunity to understand the virulence of C. difficile better and find markers for better clinical use
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