694 research outputs found
Microeconomic Evidence of Nominal Wage Rigidities in Chile
This document presents new evidence on the adjustment frequency of wages in Chile and their fundamentals. The data come from a database built from information gathered by the Chilean safety association Asociación Chilena de Seguridad (AChS). The base consists of a panel of 429 thousand wage records for the period 2001.12–2007.12. The results indicate that, on average, wages take a little over nine quarters to adjust completely. As for the determinants of such adjustments, the degree of downward flexibility of wages depends positively on the participation of younger workers (under 30), positively on firm size, and negatively on the proportion of high income workers. Finally, the sectoral effects are statistical and economically significant.
The emergent role of digital technologies in the context of humanitarian supply chains: a systematic literature review
The role of digital technologies (DTs) in humanitarian supply chains (HSC) has become an increasingly researched topic in the operations literature. While numerous publications have dealt with this convergence, most studies have focused on examining the implementation of individual DTs within the HSC context, leaving relevant literature, to date, dispersed and fragmented. This study, through a systematic literature review of 110 articles on HSC published between 2015 and 2020, provides a unified overview of the current state-of-the-art DTs adopted in HSC operations. The literature review findings substantiate the growing significance of DTs within HSC, identifying their main objectives and application domains, as well as their deployment with respect to the different HSC phases (i.e., Mitigation, Preparedness, Response, and Recovery). Furthermore, the findings also offer insight into how participant organizations might configure a technological portfolio aimed at overcoming operational difficulties in HSC endeavours. This work is novel as it differs from the existing traditional perspective on the role of individual technologies on HSC research by reviewing multiple DTs within the HSC domain
Molecular evolution of cytochrome \u3ci\u3eb\u3c/i\u3e in high- and low-altitude deer mice (genus \u3ci\u3ePeromyscus\u3c/i\u3e)
Patterns of amino-acid polymorphism in human mitochondrial genes have been interpreted as evidence for divergent selection among populations that inhabit climatically distinct environments. If similar patterns are mirrored in other broadly distributed mammalian species, then adaptive modifications of mitochondrial protein function may be detected in comparisons among locally adapted populations of a single wide-ranging species, or among closely related species that have adapted to different environments. Here, we test for evidence of positive selection on cytochrome b variation within and among species of the ecologically diverse rodent genus Peromyscus. We used likelihood-based comparisons of synonymous and nonsynonymous substitution rates to test for evidence of divergent selection between high- and low-altitude haplogroups of the deer mouse, Peromyscus maniculatus. We also tested for evidence of divergent selection among different species of Peromyscus that inhabit different thermal environments. In contrast to the purported evidence for positive selection on mitochondrial proteins in humans and other nonhuman mammals, results of our tests suggest that the evolution of cytochrome b in Peromyscus is chiefly governed by purifying selection
Molecular evolution of cytochrome \u3ci\u3eb\u3c/i\u3e in high- and low-altitude deer mice (genus \u3ci\u3ePeromyscus\u3c/i\u3e)
Patterns of amino-acid polymorphism in human mitochondrial genes have been interpreted as evidence for divergent selection among populations that inhabit climatically distinct environments. If similar patterns are mirrored in other broadly distributed mammalian species, then adaptive modifications of mitochondrial protein function may be detected in comparisons among locally adapted populations of a single wide-ranging species, or among closely related species that have adapted to different environments. Here, we test for evidence of positive selection on cytochrome b variation within and among species of the ecologically diverse rodent genus Peromyscus. We used likelihood-based comparisons of synonymous and nonsynonymous substitution rates to test for evidence of divergent selection between high- and low-altitude haplogroups of the deer mouse, Peromyscus maniculatus. We also tested for evidence of divergent selection among different species of Peromyscus that inhabit different thermal environments. In contrast to the purported evidence for positive selection on mitochondrial proteins in humans and other nonhuman mammals, results of our tests suggest that the evolution of cytochrome b in Peromyscus is chiefly governed by purifying selection
Oxygen uptake kinetics to assess cardiorespiratory fitness in obese patients
Indexación: Scopus.Background:
The evaluation of cardiorespiratory fitness (RCC) using maximal or peak oxygen consumption (VO2), requires a high level of effort in obese patients. We propose a method to evaluate RCC using constant and moderate loads, called VO2 kinetics (tau).
Aim:
To determine the relationship between tau and peak VO2 in patients with obesity.
Material and Methods:
Forty patients (87% females) aged 37 ± 12 years and with a body mass index (BMI) of 34.6 ± 4.0 kg/m2, were divided into two groups according to the applied workload (0.5 and 0.8 Watts/kg body mass) using a cycle ergometer and Cortex Metalyzer 3b equipment. The protocol was started with 6 minutes at constant load and then increments of 20-25 Watts every two min were made until determination of the peak VO2.
Results:
The tau value was 51.8 ± 17.6 s, the absolute peak VO2 was 2.0 ± 0.7 L/min and the relative peak VO2 was 26.6 ± 30.0 ml/kg/min. There was a significant difference of tau medians between the group that used 0.5 and 0.8 Watts/kg (p = 0.002) and a significant inverse correlation between the absolute peak VO2 and the tau value for a load of 0.5 Watts/kg (rho = -0.415, p = 0.0327).
Conclusions:
The higher tau value, the lower the peak VO2 of an obese patient. It is suggested to apply loads of 0.5 Watts/kg for a VO2 kinetics test in obese patients or in subjects who do not wish to carry out higher physiological demands with a non-invasive and low risk procedure.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0034-98872018000100015&lng=en&nrm=iso&tlng=e
Wnt/β-catenin signaling stimulates the expression and synaptic clustering of the autism-associated Neuroligin 3 gene
Indexación: Scopus.Synaptic abnormalities have been described in individuals with autism spectrum disorders (ASD). The cell-adhesion molecule Neuroligin-3 (Nlgn3) has an essential role in the function and maturation of synapses and NLGN3 ASD-associated mutations disrupt hippocampal and cortical function. Here we show that Wnt/β-catenin signaling increases Nlgn3 mRNA and protein levels in HT22 mouse hippocampal cells and primary cultures of rat hippocampal neurons. We characterized the activity of mouse and rat Nlgn3 promoter constructs containing conserved putative T-cell factor/lymphoid enhancing factor (TCF/LEF)-binding elements (TBE) and found that their activity is significantly augmented in Wnt/β-catenin cell reporter assays. Chromatin immunoprecipitation (ChIP) assays and site-directed mutagenesis experiments revealed that endogenous β-catenin binds to novel TBE consensus sequences in the Nlgn3 promoter. Moreover, activation of the signaling cascade increased Nlgn3 clustering and co-localization with the scaffold PSD-95 protein in dendritic processes of primary neurons. Our results directly link Wnt/β-catenin signaling to the transcription of the Nlgn3 gene and support a functional role for the signaling pathway in the dysregulation of excitatory/inhibitory neuronal activity, as is observed in animal models of ASD.https://www.nature.com/articles/s41398-018-0093-y.pd
Carney triad. Report of one case
Indexación: Scopus.Carney described a disorder characterized by the presence of several uncommon tumors which were pulmonary chondromas, gastric sarcomas and extra-adrenal paragangliomas. We report a 14 year-old girl in whom multiple gastric tumors were discovered during a study of an iron deficiency anemia and was subjected to a partial gastrectomy. At 25 years of age, she developed several pulmonary chondromas and at 33 years, a mediastinal tumor with features of an extra-adrenal paraganglioma was found. At 35 years of age, a total gastrectomy was performed to remove a gastrointestinal stromal tumor with excision of peritoneal and lymph node metastasis. One year later, the patient died due to liver failure secondary to liver metastases.http://ref.scielo.org/4jhgg
Gas Exchange Relations of Ungrafted Grapevines (cv. Carménère) Growing Under Irrigated Field Conditions
A study was carried out to evaluate the leaf gas exchange relations and water-use efficiency (WUE) of ungrafted Carménère (Vitis vinifera L.) grapevines growing under field conditions and different levels of water stress. Stomatal conductance (gs), transpiration (E), net CO2 assimilation (AN) and stem water potential (Ψs) were measured at midday in a drip-irrigated commercial vineyard located in the Maule Valley (Chile) during three growing seasons (2005 to 2009). In addition, the instantaneous (AN/E) and intrinsic (AN/gs) water-use efficiencies and stomatal sensitivity factor (k) were estimated for the own-rooted grapevines. In this study a significant non-linear relationship was observed between AN and gs (r2 = 0.82), with values of AN decreasing from 14.9 to 3.5 μmol/m2/sec as gs diminished from 0.5 to 0.05 mol/m2/sec. This resulted in a progressive increase in WUEi (intrinsic water use efficiency). A significant linear relationship was observed between Ψs and gs (r2 = 0.39) for measurements taken before and after véraison, with an increasing scattering from -1.6 to -0.4 MPa. Finally, k decreased as water stress increased, with values of 234 and 120 for no and severe water stress respectively, while k ranged from 264 to 480 and 255 to 297 for the measurements taken before and after véraison respectively. Based on the results obtained in the present study, the cultivar Carménère could be classified as drought tolerant at low water potentials, with a large range of physiological parameters changing in response to water stress
A genetic algorithm for resizing and sampling reduction of non-stationary soil chemical attributes optimizing spatial prediction
Aim of study: To evaluate the influence of the parameters of the geostatistical model and the initial sample configuration used in the optimization process; and to propose and evaluate the resizing of a sample configuration, reducing its sample size, for simulated data and for the study of the spatial variability of soil chemical attributes under a non-stationary with drift process from a commercial soybean cultivation area.Area of study: Cascavel, BrazilMaterial and methods: For both, the simulated data and the soil chemical attributes, the Genetic Algorithm was used for sample resizing, maximizing the overall accuracy measure.Main results: The results obtained from the simulated data showed that the practical range did not influence in a relevant way the optimization process. Moreover, the local variations, such as variance or sampling errors (nugget effect), had a direct relationship with the reduction of the sample size, mainly for the smaller nugget effect. For the soil chemical attributes, the Genetic Algorithm was efficient in resizing the sampling configuration, since it generated sampling configurations with 30 to 35 points, corresponding to 29.41% to 34.31% of the initial configuration, respectively. In addition, comparing the optimized and initial configurations, similarities were obtained regarding spatial dependence structure and characterization of spatial variability of soil chemical attributes in the study area.Research highlights: The optimization process showed that it is possible to reduce the sample size, allowing for lesser financial investments with data collection and laboratory analysis of soil samples in future experiments
Gene Turnover and Diversification of the α- and β- Globin Gene Families in Sauropsid Vertebrates
The genes that encode the α- and β-chain subunits of vertebrate hemoglobin have served as a model system for elucidating general principles of gene family evolution, but little is known about patterns of evolution in amniotes other than mammals and birds. Here,we report a comparative genomic analysis of the α- and β-globin gene clusters in sauropsids (archosaurs and nonavian reptiles). The objectives were to characterize changes in the size and membership composition of the α- and β-globin gene families within and among the major sauropsid lineages, to reconstruct the evolutionary history of the sauropsid α- and β-globin genes, to resolve orthologous relationships, and to reconstruct evolutionary changes in the developmental regulation of gene expression. Our comparisons revealed contrasting patterns of evolution in the unlinked α- and β-globin gene clusters. In the α-globin gene cluster,which has remained in the ancestral chromosomal location, evolutionary changes in gene content are attributable to the differential retention of paralogous gene copies that were present in the common ancestor of tetrapods. In the β-globin gene cluster, which was translocated to a new chromosomal location, evolutionary changes in gene content are attributable to differential gene gains (via lineage-specific duplication events) and gene losses (via lineage-specific deletions and inactivations). Consequently, all major groups of amniotes possess unique repertoires of embryonic and postnatally expressed β-type globingenes that diversified independently in each lineage.These independently derived β-type globins descend from a pair of tandemly linked paralogs in the most recent common ancestor of sauropsids
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