580 research outputs found
Transmission fiber chromatic dispersion dependence on temperature: implications on 40 Gb/s performance
In this letter we will evaluate the performance degradation of a 40 km high-speed (40 Gb/s) optical System, induced by optical fiber variations of the chromatic dispersion induced by temperature changes. The chromatic dispersion temperature sensitivity will be estimated based on the signal quality parameters
Primate modularity and evolution: first anatomical network analysis of primate head and neck musculoskeletal system
Network theory is increasingly being used to study morphological modularity and integration. Anatomical network analysis (AnNA) is a framework for quantitatively characterizing the topological organization of anatomical structures and providing an operational way to compare structural integration and modularity. Here we apply AnNA for the first time to study the macroevolution of the musculoskeletal system of the head and neck in primates and their closest living relatives, paying special attention to the evolution of structures associated with facial and vocal communication. We show that well-defined left and right facial modules are plesiomorphic for primates, while anthropoids consistently have asymmetrical facial modules that include structures of both sides, a change likely related to the ability to display more complex, asymmetrical facial expressions. However, no clear trends in network organization were found regarding the evolution of structures related to speech. Remarkably, the increase in the number of head and neck muscles – and thus of musculoskeletal structures – in human evolution led to a decrease in network density and complexity in humans
International collaborative project to compare and track the nutritional composition of fast foods
BackgroundChronic diseases are the leading cause of premature death and disability in the world with over-nutrition a primary cause of diet-related ill health. Excess quantities of energy, saturated fat, sugar and salt derived from fast foods contribute importantly to this disease burden. Our objective is to collate and compare nutrient composition data for fast foods as a means of supporting improvements in product formulation.Methods/designSurveys of fast foods will be done in each participating country each year. Information on the nutrient composition for each product will be sought either through direct chemical analysis, from fast food companies, in-store materials or from company websites. Foods will be categorized into major groups for the primary analyses which will compare mean levels of saturated fat, sugar, sodium, energy and serving size at baseline and over time. Countries currently involved include Australia, New Zealand, France, UK, USA, India, Spain, China and Canada, with more anticipated to follow.DiscussionThis collaborative approach to the collation and sharing of data will enable low-cost tracking of fast food composition around the world. This project represents a significant step forward in the objective and transparent monitoring of industry and government commitments to improve the quality of fast foods.<br /
Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy
How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual's survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA), to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs) and diverse or complex tissue composition (e.g. bones, cartilages and muscles), by quantifying the spatial organization of these parts-their topological patterns relative to each other-using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are serial homologues. In addition, the AnNA of the limbs of a trisomy 18 human fetus strongly supports Pere Alberch's ill-named "logic of monsters" hypothesis, and contradicts the commonly accepted idea that birth defects often lead to lower integration (i.e. more parcellation) of anatomical structures
Critical evaluation of proteomic protocols for passion fruit (Passiflora edulis Sims) leaves, a crop with juice market benefits
Passion fruit grows practically all over Brazilian territory; its production is largely destined to juice industry and expanding to overseas markets. The suitability of four protein extraction protocols for plant proteome was investigated to determine the best choice for studies concerning passion fruit leaf proteins. Trichloroacetic acid (TCA)/acetone extraction; isoelectric focusing (IEF) buffer extraction; phenol (Phe) extraction and Phe-SDS extraction were tested. The Phe method produced the best results, showing higher reproducibility of resolved protein spots and clearer 2D gel background staining. In comparison, the Phe-SDS method presented fewer spots and lower reproducibility. The TCA/acetone method produced the fewest identifiable spots and the IEF buffer produced the poorest results,displaying fewer reproducibly detected spots, more vertical streaks and darker 2D staining. Selected spots, obtained with Phe method, were identified by spectrometric analysis (MALDI-TOF-TOF) to exemplify the viability to perform more comprehensive proteomic studies with passion fruit leaves and, therefore increase information about stress-related and developmental responses in this fruit crop.Key words: Passion fruit, proteomic, protein extraction, juice industry
Pb(II) Induces Scramblase Activation and Ceramide-Domain Generation in Red Blood Cells
The mechanisms of Pb(II) toxicity have been studied in human red blood cells using confocal microscopy, immunolabeling, fluorescence-activated cell sorting and atomic force microscopy. The process follows a sequence of events, starting with calcium entry, followed by potassium release, morphological change, generation of ceramide, lipid flip-flop and finally cell lysis. Clotrimazole blocks potassium channels and the whole process is inhibited. Immunolabeling reveals the generation of ceramide-enriched domains linked to a cell morphological change, while the use of a neutral sphingomyelinase inhibitor greatly delays the process after the morphological change, and lipid flip-flop is significantly reduced. These facts point to three major checkpoints in the process: first the upstream exchange of calcium and potassium, then ceramide domain formation, and finally the downstream scramblase activation necessary for cell lysis. In addition, partial non-cytotoxic cholesterol depletion of red blood cells accelerates the process as the morphological change occurs faster. Cholesterol could have a role in modulating the properties of the ceramide-enriched domains. This work is relevant in the context of cell death, heavy metal toxicity and sphingolipid signaling.AGA was a predoctoral student supported by the Basque Government and later by the University of the Basque Country (UPV/EHU). This work was also supported in part by grants from the Spanish Government (FEDER/MINECO BFU 2015-66306-P to F.M.G. and A.A.) and the Basque Government (IT849-13 to F.M.G. and IT838-13 to A.A.), and by the Swiss National Science Foundation
Testicular morphology of adult wistar rats treated with Rudgea viburnoides (Cham.) Benth. leaf infusion
The present study was carried out to investigate the effects of Rudgea viburnoides infusion on the body biometry and testicular morphometry and stereology of adult Wistar rats. Two groups received the infusion daily at the concentration of 3 or 6 mg/mL for 40 days. The control group received only water. Neither the biometrical parameters nor the tubular diameter and the height of the seminiferous epithelium showed any significant alterations in the treated animals. Leydig cells stereology did not show any significant alterations in the treated animals. These results indicated that R. viburnoides did not cause alterations in body biometry and testicular morphometry
Network-Based Integration of GWAS and Gene Expression Identifies a HOX-Centric Network Associated with Serous Ovarian Cancer Risk
BACKGROUND: Genome-wide association studies (GWAS) have so far reported 12 loci associated with serous epithelial ovarian cancer (EOC) risk. We hypothesized that some of these loci function through nearby transcription factor (TF) genes and that putative target genes of these TFs as identified by coexpression may also be enriched for additional EOC risk associations. METHODS: We selected TF genes within 1 Mb of the top signal at the 12 genome-wide significant risk loci. Mutual information, a form of correlation, was used to build networks of genes strongly coexpressed with each selected TF gene in the unified microarray dataset of 489 serous EOC tumors from The Cancer Genome Atlas. Genes represented in this dataset were subsequently ranked using a gene-level test based on results for germline SNPs from a serous EOC GWAS meta-analysis (2,196 cases/4,396 controls). RESULTS: Gene set enrichment analysis identified six networks centered on TF genes (HOXB2, HOXB5, HOXB6, HOXB7 at 17q21.32 and HOXD1, HOXD3 at 2q31) that were significantly enriched for genes from the risk-associated end of the ranked list (P < 0.05 and FDR < 0.05). These results were replicated (P < 0.05) using an independent association study (7,035 cases/21,693 controls). Genes underlying enrichment in the six networks were pooled into a combined network. CONCLUSION: We identified a HOX-centric network associated with serous EOC risk containing several genes with known or emerging roles in serous EOC development. IMPACT: Network analysis integrating large, context-specific datasets has the potential to offer mechanistic insights into cancer susceptibility and prioritize genes for experimental characterization
Biodiversity and ecosystem services in quarries
Although covering less than 1% of the land surface, extraction activities have long‐lasting impacts on local ecosystems, inevitably damaging biological diversity and depleting ecosystem services. Many extractive companies are now aware of their impacts and, while pressured by society, demand concrete solutions from researchers to reverse the effects of exploitation and restore biodiversity and ecosystems services. In this article, we compile and synthesize the contributions of the latest available research on quarry restoration. We depict and discuss some of the most pressing issues regarding (1) the challenges of restoring quarries; (2) the opportunities for biodiversity and ecosystem services delivery; and (3) outline further research addressing current gaps. We conclude that quarries pose different abiotic and biotic constraints that act interdependently, hampering the attainment of effective restoration if considered solely. Such constraints need to be addressed holistically to lastly encourage the self‐sustainability of the system by reinstating ecological processes. However, a restored site does not have to specifically mimic the pristine situation, as under certain conditions alternative approaches may uphold valuable natural assets contributing to the conservation of rare, restricted, or protected species and habitats.Czech Grant Agency by the project no. 20-06065Sinfo:eu-repo/semantics/publishedVersio
Exome genotyping arrays to identify rare and low frequency variants associated with epithelial ovarian cancer risk
Rare and low frequency variants are not well covered in most germline genotyping arrays and are understudied in relation to epithelial ovarian cancer (EOC) risk. To address this gap, we used genotyping arrays targeting rarer protein-coding variation in 8,165 EOC cases and 11,619 controls from the international Ovarian Cancer Association Consortium (OCAC). Pooled association analyses were conducted at the variant and gene level for 98,543 variants directly genotyped through two exome genotyping projects. Only common variants that represent or are in strong linkage disequilibrium (LD) with previously-identified signals at established loci reached traditional thresholds for exome-wide significance (P ( )P≥5.0 ×10 (-) (7)) were detected for rare and low-frequency variants at 16 novel loci. Four rare missense variants were identified (ACTBL2 rs73757391 (5q11.2), BTD rs200337373 (3p25.1), KRT13 rs150321809 (17q21.2) and MC2R rs104894658 (18p11.21)), but only MC2R rs104894668 had a large effect size (OR = 9.66). Genes most strongly associated with EOC risk included ACTBL2 (PAML = 3.23 × 10 (-) (5); PSKAT-o = 9.23 × 10 (-) (4)) and KRT13 (PAML = 1.67 × 10 (-) (4); PSKAT-o = 1.07 × 10 (-) (5)), reaffirming variant-level analysis. In summary, this large study identified several rare and low-frequency variants and genes that may contribute to EOC susceptibility, albeit with possible small effects. Future studies that integrate epidemiology, sequencing, and functional assays are needed to further unravel the unexplained heritability and biology of this disease
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