Caña Brava : trabajo y organización social entre los cortadores de caña

1 archivo PDF (182 páginas)Se analiza el proceso de trabajo en el que están involucrados los cortadores de caña y se presentan algunas experiencias de organización de esta fracción del proletariado agrícol

Las redes inalámbricas de área local ("Wi-Fi") en la FCC y el CNAF

En los últimos años, las Redes Inalámbricas de Área Local (WLAN, Wireless Local Área Networks) basadas en el estándar IEEE (802.11 [1] y sus derivados ñan conseguido unos altos niveles de implantación y desbordar el ámbito de aplicaciones y servicios para los que fueron inicialmente concebidas. De hecho, que se ñan convertido en un fenómeno tecnológico

Modeled climate change effects on distributions of Canadian butterfly species

Abstract: Climate change effects on biodiversity are being documented now frequently in the form of changes in phenology and distributional shifts. However, the form that these effects will take over a longer timespan is unclear; for this understanding, a quantitative, validated, predictive approach is key. Here, we use ecological niche modeling and general circulation model outputs to estimate future potential geographic distributions of 111 Canadian butterfly species. We develop future estimates under two emission scenarios from each of two climate change modeling centers; future projections for biodiversity are not only scenario dependent (more severe emission scenarios produce more severe effects on species’ distributions) but also model dependent (the Canadian Centre for Climate Modelling and Analysis results were more severe than the Hadley Centre results). One interesting feature is the appearance of disjunctions in species’ distributions, hence creating “vicariant events” over very short time periods. In general, however, a cost of 1%–3% additional loss of species’ distributions is associated with more severe scenarios of emissions and climate change, suggesting that subtle biodiversity consequences are associated with the different climate futures debated in political circles. Résumé : La littérature scientifique courante traite fréquemment des effets des changements climatiques sur la biodiversité, particulièrement en ce qui a trait aux changements phénologiques et aux modifications des répartitions géographiques. Cependant, la forme que prendront ces effets sur une échelle temporelle plus longue reste à préciser, car pour ce faire il est nécessaire d’avoir recours à une approche quantitative, validée et prédictive. Les résultats d’une modélisation de la niche écologique et de modèles de circulation générale nous ont servi à estimer la répartition géographique potentielle future de 111 espèces de papillons canadiens. Nous avons basé nos prédictions sur deux scénarios d’émissions provenant de deux centres de modélisation du climat; ces prédictions de la biodiversité dépendent non seulement du scénario choisi (les scénarios d’émissions plus importantes produisent des effets plus marqués sur la répartition des espèces), mais aussi du modèle retenu (les résultats du Centre canadien pour la modélisation et l’analyse du climatique sont plus rigoureux que ceux du Centre Hadley). Une caractéristique intéressante est l’apparition de fragmentations dans la répartition des espèces, ce qui crée des « événements de vicariance » sur de très courtes périodes. En général, cependant, un coût de 1 % – 3 % en perte additionnelle dans les répartitions accompagne les scénarios les plus rigoureux de changement climatique, ce qui indique que les conséquences sur la biodiversité des divers scénarios climatiques futurs discutés dans les milieux politiques sont assez subtiles. [Traduit par la Rédaction

Despliegue de redes inalámbricas (WI-FI): planificación radio

Desde hace apenas tres años, una tecnología, o quizás sería más exacto, un protocolo de comunicaciones empezó a despuntar con éxito y vistas de un tremendo futuro. Esta tecnología basada en el estándar IEEE 802.11b y conocida como Wi-Fi (“Wireless Fidelity”) ha conseguido unos altos niveles de implantación, desbordar el ámbito de aplicaciones y servicios para los que fue inicialmente concebida y ser un poderoso complemento a otras tecnologías que requieren importantes infraestructuras y altos niveles de inversión

Hysteroscopic findings and intrauterine pathology treatment in Mexican infertile women

Background: Hysteroscopy is a minimally invasive approach in gynecologic surgery and one of the main procedures performed on women undergoing fertility treatments. Intrauterine pathology negatively affects fertility by decreasing endometrial receptivity and embryo implantation success, and its prevalence has been reported between 19% and 62%. The aim of our study was to describe the hysteroscopic findings, prevalence of intrauterine pathology, the instruments used for the treatment of structural lesions in Mexican infertile women; and to compare the relationship of positive findings with the type of infertility. Methods: This was a descriptive, cross-sectional study conducted at fertility clinic at a private hospital. Results: We evaluated 191 hysteroscopies; the mean age of women was 35.5+3.2 years and the mean time of infertility 5.7+3.2 years. Primary infertility was the most prevalent (79.1%). In 118 cases (61.8%), uterine cavity abnormalities were diagnosed, the most frequent findings were: polyps (n=51, 26.7%), endometritis (n=30, 15.7%), fibroids (n=15, 7.6 %), synechiae (n=12, 6.5%), and müllerian anomalies (n=10, 5.3%). For structural pathology treatment, cold scissors and bipolar energy were used in 65.5% and 34.5%, respectively. Conclusions: Overall intrauterine pathology prevalence in our study population was 61.8%. Cold scissors and bipolar energy were used for structural lesions treatment. When comparing the relationship of hysteroscopic findings, no statistically significant difference was found in the presence of positive findings, with the type of infertility.

A case–control study to assess the effectiveness of pertussis vaccination during pregnancy on newborns, Valencian community, Spain, 1 March 2015 to 29 February 2016

In the Valencian Community (Spain), the programme of maternal pertussis vaccination during pregnancy started in January 2015. The objective of this study was to estimate in this region the vaccine effectiveness (VE) in protecting newborns against laboratory-confirmed pertussis infection. A matched case–control study was undertaken in the period between 1 March 2015 and 29 February 2016. Twenty-two cases and 66 controls (+/− 15 days of age difference) were included in the study. Cases were non-vaccinated infants < 3 months of age at disease onset testing positive for pertussis by real-time PCR. For every case three unvaccinated controls were selected. Odds ratios (OR) were calculated by multiple conditional logistic regression for association between maternal vaccination and infant pertussis. Other children in the household, as well as mother- and environmental covariates were taken into account. The VE was calculated as 1 − OR. Mothers of five cases (23%) and of 41 controls (62%) were vaccinated during pregnancy. The adjusted VE was 90.9% (95% confidence interval (CI): 56.6 to 98.1). The only covariate in the final model was breastfeeding (protective effect). Our study provides evidence in favour of pertussis vaccination programmes for pregnant women in order to prevent whooping cough in infants aged less than 3 months

par genes in Mycobacterium bovis and Mycobacterium smegmatis are arranged in an operon transcribed from "SigGC" promoters

<p>Abstract</p> <p>Background</p> <p>The ParA/Soj and ParB/Spo0J proteins, and the <it>cis</it>-acting <it>parS </it>site, participate actively in chromosome segregation and cell cycle progression. Genes homologous to <it>parA </it>and <it>parB</it>, and two putative <it>parS </it>copies, have been identified in the <it>Mycobacterium bovis </it>BCG and <it>Mycobacterium smegmatis </it>chromosomes. As in <it>Mycobacterium tuberculosis</it>, the <it>parA </it>and <it>parB </it>genes in these two non-pathogenic mycobacteria are located near the chromosomal origin of replication. The present work focused on the determination of the transcriptional organisation of the ~6 Kb <it>orf60K-parB </it>region of <it>M. bovis </it>BCG and <it>M. smegmatis </it>by primer extension, transcriptional fusions to the green fluorescence protein (GFP) and quantitative RT-PCR.</p> <p>Results</p> <p>The <it>parAB </it>genes were arranged in an operon. However, we also found promoters upstream of each one of these genes. Seven putative promoter sequences were identified in the <it>orf60K-parB </it>region of <it>M. bovis </it>BCG, whilst four were identified in the homologous region of <it>M. smegmatis</it>, one upstream of each open reading frame (ORF).</p> <p>Real-time PCR assays showed that in <it>M. smegmatis</it>, mRNA-<it>parA </it>and mRNA-<it>parB </it>levels decreased between the exponential and stationary phases. In <it>M. bovis </it>BCG, mRNA-<it>parA </it>levels also decreased between the exponential and stationary phases. However, <it>parB </it>expression was higher than <it>parA </it>expression and remained almost unchanged along the growth curve.</p> <p>Conclusion</p> <p>The majority of the proposed promoter regions had features characteristic of <it>Mycobacterium </it>promoters previously denoted as Group D. The -10 hexamer of a strong <it>E. coli </it>σ⁷⁰-like promoter, located upstream of <it>gidB </it>of <it>M. bovis </it>BCG, overlapped with a putative <it>parS </it>sequence, suggesting that the transcription from this promoter might be regulated by the binding of ParB to <it>parS</it>.</p