1,150 research outputs found
Twenty Years of Disturbance and Change in Fagatele Bay National Marine Sanctuary, American Samoa
Fagatele Bay National Marine Sanctuary contains a moderately
diverse coral reef community (150 coral species, 259 fish species) that is protected
from most human activities. The coral community was devastated by a
crown-of-thorns starfish invasion in 1979 and has recently been affected by two
major hurricanes (1990 and 1991) and a period of unusually high water temperature
(1994). Long-term monitoring of the sanctuary allows for description of
the effects of these disturbances in the absence of anthropogenic processes. The
crown-of-thorns damaged deeper portions of the coral communities most severely,
whereas the hurricanes and warm water affected shallower portions to
a greater degree. Soon after these disturbances, corals started recruiting abundantly
and the reefs began to recover. This is in contrast to some other areas in
American Samoa, where chronic anthropogenic effects seem to have inhibited
coral recruitment and reef recovery. Fish communities were affected by the habitat
degradation associated with the crown-of-thorns outbreak, but have remained
relatively unchanged ever since
Effects of Monensin on metabolic profile and feeding behavior of transition dairy cows
Thirty-two Holstein transition cows were used to determine the effects of monensin (Rumensin, Elanco Animal Health, Greenfield, IN; 400 mg/cow daily) on metabolism and feeding behavior. Cows were assigned randomly, based on calving date, to control or monensin treatments (n = 16 per treatment) 21 days before their expected calving date, and cows remained on treatments through 21 days in milk. Feeding behavior and water intake data were collected daily. Blood samples were collected at 8 different time points during the experimental period. Monensin decreased mean and peak plasma ketone concentrations, and also decreased time between meals before and after calving. No effects of monensin supplementation were observed on milk production or other metabolic traits. Furthermore, we observed no treatment effects on disease incidence, although sample size was small for detecting such effects.; Dairy Day, 2011, Kansas State University, Manhattan, KS, 2011; Dairy Research, 2011 is known as Dairy Day, 201
JAK2V617F promotes replication fork stalling with disease-restricted impairment of the intra-S checkpoint response
Cancers result from the accumulation of genetic lesions, but the cellular consequences of driver mutations remain unclear, especially during the earliest stages of malignancy. The V617F mutation in the JAK2 non-receptor tyrosine kinase (JAK2V617F) is present as an early somatic event in most patients with myeloproliferative neoplasms (MPNs), and the study of these chronic myeloid malignancies provides an experimentally tractable approach to understanding early tumorigenesis. Introduction of exogenous JAK2V617F impairs replication fork progression and is associated with activation of the intra-S checkpoint, with both effects mediated by phosphatidylinositide 3-kinase (PI3K) signaling. Analysis of clonally derived JAK2V617F-positive erythroblasts from MPN patients also demonstrated impaired replication fork progression accompanied by increased levels of replication protein A (RPA)-containing foci. However, the associated intra-S checkpoint response was impaired in erythroblasts from polycythemia vera (PV) patients, but not in those from essential thrombocythemia (ET) patients. Moreover, inhibition of p53 in PV erythroblasts resulted in more gamma-H2Ax (γ-H2Ax)–marked double-stranded breaks compared with in like-treated ET erythroblasts, suggesting the defective intra-S checkpoint function seen in PV increases DNA damage in the context of attenuated p53 signaling. These results demonstrate oncogene-induced impairment of replication fork progression in primary cells from MPN patients, reveal unexpected disease-restricted differences in activation of the intra-S checkpoint, and have potential implications for the clonal evolution of malignancies
A cross sectional study of the prevalence and associated risks for bursitis in 6250 weaner, grower and finisher pigs from 103 British pig farms
A cross-sectional study of 93 farms in England was carried out to estimate the prevalence and associated risk factors for bursitis. A total of 6250 pigs aged 6–22 weeks were examined for presence and severity of bursitis. Details of pen construction, pen quality and farm management were recorded including floor type, presence of bedding, condition of the floor and floor materials. The prevalence of bursitis was 41.2% and increased with each week of age (OR 1.1). Two-level logistic regression models were developed with the outcome as the proportion of pigs affected with bursitis in a pen. Pigs kept on soil floors with straw bedding were used as the reference level. In comparison with these soil floors, bursitis increased on concrete floors where the bedding was deep throughout (OR 4.6), deep in part (OR 3.7), and sparse throughout (OR 9.0), part slatted floors (OR 8.0), and fully slatted floors (OR 18.8). Slip or skid marks in the dunging area (OR 1.5), pigs observed slipping during the examination of the pen (OR 1.3) and wet floors (OR 3.6) were also associated with an increased risk of bursitis. The results indicate that bursitis is a common condition of growing pigs and that the associated risk factors for bursitis were a lack of bedding in the lying area, presence of voids and pen conditions which increased the likelihood of injury
Dense circumnuclear molecular gas in starburst galaxies
We present results from a study of the dense circumnuclear molecular gas of starburst galaxies. The study aims to investigate the interplay between starbursts, active galactic nuclei and molecular gas.We characterize the dense gas traced by HCN, HCO and HNC and examine its kinematics in the circumnuclear regions of nine starburst galaxies observed with the Australia Telescope Compact Array. We detect HCN (1-0) and HCO (1-0) in seven of the nine galaxies and HNC (1-0) in four. Approximately 7 arcsec resolution maps of the circumnuclear molecular gas are presented. The velocity-integrated intensity ratios, HCO (1-0)/HCN (1-0) and HNC (1-0)/HCN (1-0), are calculated. Using these integrated intensity ratios and spatial intensity ratio maps, we identify photon-dominated regions (PDRs) in NGC 1097, NGC 1365 and NGC 1808. We find no galaxy which shows the PDR signature in only one part of the observed nuclear region.We also observe unusually strong HNC emission in NGC 5236, but it is not strong enough to be consistent with X-ray-dominated region chemistry. Rotation curves are derived for five of the galaxies and dynamical mass estimates of the inner regions of three of the galaxies are made. © 2016 The Authors.This project was supported by the Brother Vincent Cotter Award for Physics (UNSW). LVM has been supported by Grant AYA2011-30491-C02-01 co-financed by MICINN and FEDER funds, and the Junta de Andalucia (Spain) grants P08-FQM-4205 and TIC-114. WAB acknowledges the support as a Visiting Professor of the Chinese Academy of Sciences (KJZD-EW-T01). The research leading to these results has received funding from the European Community's Seventh Framework Programme (/FP7/2007-2013/) under grant agreement No 229517.Peer Reviewe
STAT1 activation in association with JAK2 exon 12 mutations
La inclusión de la perspectiva de género en la actividad jurisdiccional es una demanda sostenida de los colectivos feministas y de mujeres, dado que las sentencias tienen un poder performativo y envían un mensaje a la sociedad: “[…] tienen un poder individual y colectivo que impactan en la vida de las personas y conforman la identidad del poder judicial como un actor imprescindible en la construcción de un Estado democrático de derecho” (Suprema Corte de Justicia de la Nación, 2013:7). La incorporación de la perspectiva de género viene a garantizar la igualdad de posiciones (Kessler, 2014) entre mujeres y varones como una meta, trascendiendo la mera igualdad de oportunidades que hasta el presente se ha demostrado insuficiente para que las mujeres consigamos una ciudadanía plena. Al momento de incorporar la perspectiva de género en las sentencias, quienes juzgan deben tener presente en primer lugar, el impacto diferenciado de las normas en base al sexo de las personas. En segundo lugar, la interpretación y aplicación de las leyes en relación con (y en base a) estereotipos de género. Si, por ejemplo, quienes imparten justicia no tienen presentes los estereotipos de género vigentes detrás de las violaciones a los derechos humanos de las mujeres, si no los detectan ni cuestionan, entonces los reproducen. Tal como sostiene Scott (1996) el género es una categoría imprescindible para el análisis social. En tercer lugar, al momento del juzgamiento, se deben tener en cuenta las exclusiones legitimadas por la ley por pensar el mundo en términos binarios y androcéntricos; en cuarto lugar, la distribución no equitativa de recursos y poder que opera entre varones y mujeres en el marco de una organización social patriarcal, y, por último, el trato diferenciado por género legitimado por las propias leyes.Eje 3: Tramas violentas y espacios de exclusión.Instituto de Cultura Jurídic
Study of the three-dimensional shape and dynamics of coronal loops observed by Hinode/EIS
We study plasma flows along selected coronal loops in NOAA Active Region
10926, observed on 3 December 2006 with Hinode's EUV Imaging Spectrograph
(EIS). From the shape of the loops traced on intensity images and the Doppler
shifts measured along their length we compute their three-dimensional (3D)
shape and plasma flow velocity using a simple geometrical model. This
calculation was performed for loops visible in the Fe VIII 185 Ang., Fe X 184
Ang., Fe XII 195 Ang., Fe XIII 202 Ang., and Fe XV 284 Ang. spectral lines. In
most cases the flow is unidirectional from one footpoint to the other but there
are also cases of draining motions from the top of the loops to their
footpoints. Our results indicate that the same loop may show different flow
patterns when observed in different spectral lines, suggesting a dynamically
complex rather than a monolithic structure. We have also carried out magnetic
extrapolations in the linear force-free field approximation using SOHO/MDI
magnetograms, aiming toward a first-order identification of extrapolated
magnetic field lines corresponding to the reconstructed loops. In all cases,
the best-fit extrapolated lines exhibit left-handed twist (alpha < 0), in
agreement with the dominant twist of the region.Comment: 17 pages, 6 figure
Cryptic prophages within a Streptococcus pyogenes genotype emm4 lineage
The major human pathogen Streptococcus pyogenes shares an intimate evolutionary history with mobile genetic elements, which in many cases carry genes encoding bacterial virulence factors. During recent whole-genome sequencing of a longitudinal sample of S. pyogenes isolates in England, we identified a lineage within emm4 that clustered with the reference genome MEW427. Like MEW427, this lineage was characterized by substantial gene loss within all three prophage regions, compared to MGAS10750 and isolates outside of the MEW427-like lineage. Gene loss primarily affected lysogeny, replicative and regulatory modules, and to a lesser and more variable extent, structural genes. Importantly, prophage-encoded superantigen and DNase genes were retained in all isolates. In isolates where the prophage elements were complete, like MGAS10750, they could be induced experimentally, but not in MEW427-like isolates with degraded prophages. We also found gene loss within the chromosomal island SpyCIM4 of MEW427-like isolates, although surprisingly, the SpyCIM4 element could not be experimentally induced in either MGAS10750-like or MEW427-like isolates. This did not, however, appear to abolish expression of the mismatch repair operon, within which this element resides. The inclusion of further emm4 genomes in our analyses ratified our observations and revealed an international emm4 lineage characterized by prophage degradation. Intriguingly, the USA population of emm4 S. pyogenes appeared to constitute predominantly MEW427-like isolates, whereas the UK population comprised both MEW427-like and MGAS10750-like isolates. The degraded and cryptic nature of these elements may have important phenotypic and fitness ramifications for emm4 S. pyogenes , and the geographical distribution of this lineage raises interesting questions on the population dynamics of the genotype
Development of PCL polyHIPE substrates for 3D breast cancer cell culture
Cancer is a becoming a huge social and economic burden on society, becoming one of the most significant barriers to life expectancy in the 21st century. In particular, breast cancer is one of the leading causes of death for women. One of the most significant difficulties to finding efficient therapies for specific cancers, such as breast cancer, is the efficiency and ease of drug development and testing. Tissue-engineered (TE) in vitro models are rapidly developing as an alternative to animal testing for pharmaceuticals. Additionally, porosity included within these structures overcomes the diffusional mass transfer limit whilst enabling cell infiltration and integration with surrounding tissue. Within this study, we investigated the use of high-molecular-weight polycaprolactone methacrylate (PCL–M) polymerised high-internal-phase emulsions (polyHIPEs) as a scaffold to support 3D breast cancer (MDA-MB-231) cell culture. We assessed the porosity, interconnectivity, and morphology of the polyHIPEs when varying mixing speed during formation of the emulsion, successfully demonstrating the tunability of these polyHIPEs. An ex ovo chick chorioallantoic membrane assay identified the scaffolds as bioinert, with biocompatible properties within a vascularised tissue. Furthermore, in vitro assessment of cell attachment and proliferation showed promising potential for the use of PCL polyHIPEs to support cell growth. Our results demonstrate that PCL polyHIPEs are a promising material to support cancer cell growth with tuneable porosity and interconnectivity for the fabrication of perfusable 3D cancer models
How do measurement duration and timing interact to influence estimation of basal physiological variables of a nocturnal rodent?
Metabolic rate and evaporative water loss are two commonly measured physiological variables. It is therefore important, especially for comparative studies, that these variables (and others) are measured under standardised conditions, of which a resting state during the inactive phase is part of the accepted criteria. Here we show how measurement duration and timing affect these criteria and impact on the estimation of basal metabolic rate (oxygen consumption and carbon dioxide production) and standard evaporative water loss of a small nocturnal rodent. Oxygen consumption, carbon dioxide production and evaporative water loss all decreased over the duration of an experiment. Random assortment of hourly values indicated that this was an animal rather than a random effect for up to 11 h. Experimental start time also had a significant effect on measurement of physiological variables. A longer time period was required to achieve minimal carbon dioxide consumption and evaporative water loss when experiments commenced earlier in the day; however, experiments with earlier start times had a lower overall estimates of minimal oxygen consumption and carbon dioxide production. For this species, measurement duration of at least 8 h, ideally commencing between before the inactive phase at 03:00 h and 05:00 h, is required to obtain minimal standard values for physiological variables. Up to 80% of recently published studies measuring basal metabolic rate and/or evaporative water loss of small nocturnal mammals may overestimate basal values due to insufficiently long measurement duration
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