2,815 research outputs found
Sectoral allocation by gender of Latin American workers over the liberalization period of the 1990s
Full text linkThe recent restructuring of Latin American economies has renewed interest in the effects of trade liberalization, on labor markets, and on the gender division of labor. The author does not attempt to establish casuality between economic reforms, and the types of jobs that men and women hold. Instead, she provides a detailed description of the trends in male, and female formal, and informal sector participation during the economic reform period in Argentina, Brazil, and Costa Rica. The author first compares the gender composition of the formal, informal wage, and self-employment sectors in a year before reforms (1988 for Argentina, 1989 for Brazil, and Costa Rica), and a year after reforms implementation (1997 for Argentina, 1995 for Brazil and Costa Rica). Although women continued to be more likely than men to work in the informal wage sector, there is no trend of"masculinization"or"feminization"of the informal sector, or any other. Instead, in Argentina men have overtaken women as the most prevalent workers in the informal wage sector, while in Brazil, the opposite has occurred (as men move into self-employment). In Costa Rica there have been no statistical, observable changes. The author then considers the distribution across sectors within each gender group, to identify whether men, and women are more likely to select different sectors in the post-reform period relative to the pre-reform period. Among both men, and women in all three countries (except Brazilian men), workers have become more likely to hold informal wage jobs, and less likely to hold formal sector jobs. Trends in human capital accumulation explain these changes for both men, and women, while changes in gender roles, primarily in homecare and marriage, do not seem to have an effect.Health Monitoring&Evaluation,Labor Policies,Population&Development,Public Health Promotion,Environmental Economics&Policies,Health Monitoring&Evaluation,Environmental Economics&Policies,Population&Development,Banks&Banking Reform,Work&Working Conditions
Human coagulation factor X deficiency caused by a mutant signal peptide that blocks cleavage by signal peptidase but not targeting and translocation to the endoplasmic reticulum.
No full textHuman factor XSanto Domingo is a form of coagulation factor X in which a mutation
within the signal peptide region of the precursor protein has been correlated
genetically with a severe deficiency of factor X in the affected individual. A
point mutation results in substitution of Arg for Gly at the critical -3 position
of the factor X signal peptide. To determine the biochemical effect of this
mutation on the biosynthesis of factor X, the wild-type and mutant factor X cDNAs
were subcloned into a vector for transcription and translation in vitro.
Translation products of mRNAs encoding portions of both mutant and wild-type
proteins were used in a systematic biochemical approach to evaluate directly the
effect of the mutation on targeting, transport, and proteolytic processing in
vitro. The results show that targeting and transport of factor XSanto Domingo to
the endoplasmic reticulum are functionally dissociated from the removal of the
signal peptide by signal peptidase. Factor XSanto Domingo is translocated into
the endoplasmic reticulum but not processed by signal peptidase. Transient
expression of the wild-type and mutant factor X in human embryonic kidney 293
cells revealed apparently normal secretion of the glycosylated two-chain form of
factor X but no secretion of factor XSanto Domingo. Thus, the inability of signal
peptidase to cleave factor XSanto Domingo is directly responsible for the absence
of circulating factor X and leads to the bleeding diathesis in the affected
individual
The regulation of erythropoiesis by Hedgehog (Hh) signalling
Full text linkDhh (Desert Hedgehog) is one of three Hedgehog (Hh) proteins essential for testis development and Schwann cell function. Gli1, Gli2, and Gli3 are dedicated transcription factors that transduce the Hh pathway. A study published by our group showed significant changes in erythrocyte differentiation in Dhh-deficient mice, under steady state and stress-induced conditions, implicating Dhh as a negative regulator of murine erythropoiesis (Lau et al., 2012). To investigate these phenotypic differences, we created an mCherry reporter mouse line for Dhh using Bacterial Artificial Chromosome ‘recombineering’ and hypothesised that Dhh is produced by the splenic stroma, especially red pulp fibroblasts (RPFs), under steady state and anaemic stress. Erythroblast kinetics were also analysed in Hedgehog-related mouse lines during haematopoietic recovery. After validating the mCherry line as a faithful reporter of Dhh using testes, brain and thymic tissue, we found that Dhh (mCherry) is expressed by a fraction of all splenic ICAM-1+ stromal cells in particular RPFs and also fibroblast reticular cells (FRCs), disproving our steady state hypothesis. During anaemia, Dhh was not upregulated but showed most expression in the RPF subset in support of our hypothesis, while some follicular dendritic cells (FDCs) and marginal reticular cells (MRCs) significantly upregulated Dhh. Interestingly, Dhh was more highly detected in antigen-presenting cells (APCs) and some non-APCs under normal and anaemic conditions, potentially implicating Dhh in white pulp splenic functions. Irradiating Dhh-deficient mice corroborated Dhh as a negative erythropoietic regulator by analysing reticulocytes and splenic erythroid progenitors, in line with Dhh-deficient mice exhibiting less Gli-binding activity in their BM and spleen. In Gli3-heterozygote mice elevated Shh but reduced Dhh expression was found in the spleen, supporting our hypothesis that Gli3 represses Shh. Irradiating Gli3-heterozygote mice showed significant expansion of erythroblast differentiation in the BM but not the spleen, highlighting the intricacies of the Hh signalling pathway in erythropoiesis
Sox11 negatively regulates Hedgehog (Hh) signaling.
No full text<p>(A) Transverse retinal sections from 24 hpf <i>ptc2:EGFP</i> zebrafish embryos injected with control or <i>sox11</i> MO. <i>Sox11</i> morphants displayed elevated GFP expression in the brain as well as in the central and dorsal retina, and the dorsal RPE (number of embryos analyzed: control MO, n = 8; <i>sox11</i> MO, n = 10). (B) Treatment with the Hh inhibitor cyclopamine rescued the ocular phenotypes in <i>sox11</i> morphants. In contrast, treatment with the Hh agonist purmorphamine increased the prevalence of ocular phenotypes in embryos injected with a half dose of <i>sox11</i> MO. Number of embryos analyzed: 24 hpf <i>sox11MO</i> (plus 100% ethanol), n = 393; 2 dpf <i>sox11</i> MO (plus 100% ethanol), n = 319; 24 hpf <i>sox11</i> MO plus cyclopamine, n = 276; 2 dpf <i>sox11</i> MO plus cyclopamine, n = 263; 24 hpf half dose <i>sox11</i> MO (plus DMSO), n = 258; 2 dpf <i>sox11</i> MO half dose (plus DMSO), n = 241; 24 hpf uninjected plus purmorphamine, n = 83; 2 dpf uninjected plus purmorphamine, n = 81; 24 hpf half dose <i>sox11</i> MO plus purmorphamine, n = 291; 2 dpf half dose <i>sox11</i> MO plus purmorphamine, n = 270; 3 independent biological replicates. * and # p<0.0001, Fisher's exact test. (C) Treatment with cyclopamine rescued rod photoreceptor number in <i>sox11</i> morphants. Rods were counted in retinal cryosections from 3 dpf embryos. Number of embryos analyzed: control MO, n = 17; <i>sox11</i> MO, n = 20; <i>sox11</i> MO plus cyclopamine, n = 18; 3 independent replicates. *p = 0.02, Student's <i>t</i>-test). (D) Overexpression of zebrafish <i>sox11</i> increased the proportion of embryos with a cyclopic phenotype (right) compared to embryos injected with equimolar amounts of control <i>td</i>-<i>tomato</i> mRNA (left). Number of embryos analyzed: control mRNA, n = 168; <i>sox11</i> mRNA, n = 202, 3 independent biological replicates.*p<0.001, Fisher's exact test. D, dorsal; V, ventral; A, anterior; P, posterior; hpf, hours post fertilization; dpf, days post fertilization R, retina; hy, hypothalamus; L, lens; MO, morpholino.</p
Visual and haptic recognition of objects: Effects of viewpoint
No full textBuelthoff HH, Ernst MO, Newell FN, Tjan BS. Visual and haptic recognition of objects: Effects of viewpoint. Investigative Ophthalmology & Visual Science. 1999;40(4):2094
INFLUENCIA DEL PRECURSOR DE ANTIMONIO EN LA SÍNTESIS HIDROTERMAL DE CATALIZADORES Mo-V-Sb PARA LA OXIDACIÓN SELECTIVA DE PROPANO
No full textMartínez Saavedra, HH. (2009). INFLUENCIA DEL PRECURSOR DE ANTIMONIO EN LA SÍNTESIS HIDROTERMAL DE CATALIZADORES Mo-V-Sb PARA LA OXIDACIÓN SELECTIVA DE PROPANO. Universitat Politècnica de València. https://riunet.upv.es/handle/10251/13770Archivo delegad
Why liberalization alone has not improved agricultural productivity in Zambia : the role of asset ownership and working capital constraints
Full text linkThe authors use a large panel data set from Zambia to examine factors that could explain the relatively lackluster performance of the country's agricultural sector after liberalization. Zambia's liberalization significantly opened the economy but failed to alter the structure of productionor help realize efficiency gains. They reach two main conclusions. First, not owning productive assets (in Zambia, draft animals and implements) limits improvements in agricultural productivity and household welfare. Owning oxen increases income directly, allows farmers to till their fields efficiently when rain is delayed, increases the area cultivated, and improves access to credit and fertilizer markets. Second, the authors reject the hypothesis that the application of fertilizer is unprofitable because of high input prices. Rather, fertilizer use appears to have declined because of constraints on supplies, which government intervention exacerbated instead of alleviating. (Extending the use of fertilizer to the many producers not currently using it would be profitable, but increasing the amount applied by the few producers who now have access to it would not be.) Policies to foster accumulation of the assets needed for agricultural production (including draft animals and implements) and to provide complementary public goods (education, credit, and good agricultural extension services) could greatly help reduce poverty and improve productivity.Economic Theory&Research,Environmental Economics&Policies,Labor Policies,Banks&Banking Reform,Agricultural Knowledge&Information Systems,Environmental Economics&Policies,Economic Theory&Research,Banks&Banking Reform,Agricultural Knowledge&Information Systems,Agricultural Research
Effect of Cr, Mo, and V Elements on the Microstructure and Thermal Fatigue Properties of the Chromium Hot-Work Steels Processed by Selective Laser Melting
No full textThermal fatigue is the main failure mode for chromium hot-work steels. In this study, pre-alloyed chromium hot-work steel powders with three different Cr, Mo, and V addition levels (low content (LH), medium content (MH), and high content (HH)) were used for selective laser melting (SLM). The microstructure and thermal fatigue properties of these SLM-processed materials were investigated. After thermal fatigue tests, LH possessed the lowest hardness (approximately 573 HV5) and longest crack length, MH possessed the highest hardness (approximately 688 HV5) and HH (with the hardness of approximately 675 HV5) possessed the shortest crack length. It can be concluded that the increase of V content in MH is the main reason for the refined grains which result in an enhanced hardness and thermal fatigue resistance compared to LH. The further increase of the Cr and Mo content in HH leads to the grain coarsening and hardness decreasing, which is supposed to degrade the thermal fatigue resistant properties according to the conventional theory. However, HH exhibited an enhanced thermal fatigue resistance compared to MH. That is because the higher stored energy in MH deteriorated its thermal fatigue resistance compared to HH
The development and characterization of a 60K SNP chip for chicken
Full text linkAbstract Background In livestock species like the chicken, high throughput single nucleotide polymorphism (SNP) genotyping assays are increasingly being used for whole genome association studies and as a tool in breeding (referred to as genomic selection). To be of value in a wide variety of breeds and populations, the success rate of the SNP genotyping assay, the distribution of the SNP across the genome and the minor allele frequencies (MAF) of the SNPs used are extremely important. Results We describe the design of a moderate density (60k) Illumina SNP BeadChip in chicken consisting of SNPs known to be segregating at high to medium minor allele frequencies (MAF) in the two major types of commercial chicken (broilers and layers). This was achieved by the identification of 352,303 SNPs with moderate to high MAF in 2 broilers and 2 layer lines using Illumina sequencing on reduced representation libraries. To further increase the utility of the chip, we also identified SNPs on sequences currently not covered by the chicken genome assembly (Gallus_gallus-2.1). This was achieved by 454 sequencing of the chicken genome at a depth of 12x and the identification of SNPs on 454-derived contigs not covered by the current chicken genome assembly. In total we added 790 SNPs that mapped to 454-derived contigs as well as 421 SNPs with a position on Chr_random of the current assembly. The SNP chip contains 57,636 SNPs of which 54,293 could be genotyped and were shown to be segregating in chicken populations. Our SNP identification procedure appeared to be highly reliable and the overall validation rate of the SNPs on the chip was 94%. We were able to map 328 SNPs derived from the 454 sequence contigs on the chicken genome. The majority of these SNPs map to chromosomes that are already represented in genome build Gallus_gallus-2.1.0. Twenty-eight SNPs were used to construct two new linkage groups most likely representing two micro-chromosomes not covered by the current genome assembly. Conclusions The high success rate of the SNPs on the Illumina chicken 60K Beadchip emphasizes the power of Next generation sequence (NGS) technology for the SNP identification and selection step. The identification of SNPs from sequence contigs derived from NGS sequencing resulted in improved coverage of the chicken genome and the construction of two new linkage groups most likely representing two chicken micro-chromosomes.</p
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