Summary Moderate and late preterm births account for the majority of preterm babies. The common perception that birth at 32–36 weeks’ gestation carries few risks is now being challenged, as these ...babies have increased risk of neonatal mortality and morbidity. However, spontaneous labour at this gestation frequently has no specific, easily identifiable precursor, although preterm birth per se has a number of epidemiological and clinical associations. Prediction and prevention of preterm birth is currently largely aimed at identifying women at high risk such as those with previous preterm birth, and targeting intervention at this group. Both cervical length assessment and fibronectin testing permit some modification of the likelihood of preterm birth in this group. Progesterone treatment for the prevention of preterm birth is currently being researched widely, and appears a potentially promising strategy. Babies born at 32–36 weeks’ gestation need careful monitoring in labour, with modification of intervention in labour due to their prematurity.
Regular inhaled β2 agonist causes tolerance to the acute protective effect of β2 agonist against bronchoconstriction induced by chemical stimuli such as AMP, histamine, and methacholine. We examined ...a more clinically relevant stimulus, inhaled allergen, in a double-blind, cross-over, random-order trial in 13 mild atopic asthmatics, who had not used β2 agonist for at least 4 weeks. We compared regular inhaled salbutamol (200 μg four times daily for 2 weeks) with placebo (2 weeks) for effects on bronchodilator response, baseline methacholine, and allergen airway responsiveness, and on the acute protective effect of salbutamol against both stimuli. Baseline forced expiratory volume in 1 s (FEV1), bronchodilator response, and methacholine responsiveness were the same during both treatment periods. After regular salbutamol, the allergen PC20 (provocation concentration producing a 20% FEV1 decrease) fell by 0·91 (SD 0·66) (p=0·0009) doubling doses, and the protective effects of salbutamol on methacholine and allergen were both significantly reduced (p=0·026 and 0·025, respectively). Taking into account the reduced baseline allergen PC20, the post-salbutamol allergen PC20 was almost 2 doubling doses (1 94 1·43, p<0·01) lower during salbutamol treatment. Thus, 2 weeks of regular inhaled salbutamol increased airway responsiveness to allergen but not to methacholine, and caused tolerance to the protective effect of salbutamol on bronchoconstriction induced by both stimuli. These effects of inhaled β2 agonist provide further evidence to support detrimental effects of their regular use.
The first sensors of the IceCube neutrino observatory were deployed at the South Pole during the austral summer of 2004–2005 and have been producing data since February 2005. One string of 60 sensors ...buried in the ice and a surface array of eight ice Cherenkov tanks took data until December 2005 when deployment of the next set of strings and tanks began. We have analyzed these data, demonstrating that the performance of the system meets or exceeds design requirements. Times are determined across the whole array to a relative precision of better than 3
ns, allowing reconstruction of muon tracks and light bursts in the ice, of air-showers in the surface array and of events seen in coincidence by surface and deep-ice detectors separated by up to 2.5
km.
We present the results of a search for point sources of high-energy neutrinos in the northern hemisphere using AMANDA-II data collected in the year 2000. Included are flux limits on several ...active-galactic-nuclei blazars, microquasars, magnetars, and other candidate neutrino sources. A search for excesses above a random background of cosmic-ray-induced atmospheric neutrinos and misreconstructed downgoing cosmic-ray muons reveals no statistically significant neutrino point sources. We show that AMANDA-II has achieved the sensitivity required to probe known TeV gamma-ray sources such as the blazar Markarian 501 in its 1997 flaring state at a level where neutrino and gamma-ray fluxes are equal.
Although antenatal infection is thought to play an important role in the pathogenesis of preterm labor and neonatal diseases, the exact mechanisms are largely unknown. We sought to clarify the ...relationship between antenatal infection and intrauterine and neonatal inflammation. Samples were obtained from 41 preterm infants of <33 wk gestation delivered to 36 mothers and analyzed for the presence of 16s ribosomal RNA (16s rRNA) genes using PCR and for the proinflammatory cytokines IL-6 and IL-8. In 16 (44%) mother-baby pairings, at least one sample was found to be positive for the presence of 16s rRNA genes. All but one of the positive samples were from mothers presenting with preterm prelabor rupture of membranes (pPROM) or in spontaneous idiopathic preterm labor. A strong association was found between the presence of 16s rRNA genes and chorioamnionitis and with funisitis. A marked increase in IL-6 and IL-8 was noted in all tissues positive for 16s rRNA genes, including placenta, fetal membranes, cord blood serum, and, where samples were available, in bronchoalveolar lavage fluid (BAL) and in amniotic fluid. Interestingly, gastric fluid was always positive for 16s rRNA genes if any other intrauterine or BAL sample was positive, suggesting that this sample may provide an alternative to amniotic fluid to identify antenatal infection. In conclusion, we have found that microbial genes are particularly prevalent in pPROM and spontaneous preterm labor groups and that their presence is strongly associated with a marked intrauterine inflammatory response.
A search for muon neutrinos from neutralino annihilations in the Sun has been performed with the IceCube 22-string neutrino detector using data collected in 104.3 days of live time in 2007. No excess ...over the expected atmospheric background has been observed. Upper limits have been obtained on the annihilation rate of captured neutralinos in the Sun and converted to limits on the weakly interacting massive particle (WIMP) proton cross sections for WIMP masses in the range 250-5000 GeV. These results are the most stringent limits to date on neutralino annihilation in the Sun.
We present the results of searches for high-energy muon neutrinos from 41 gamma-ray bursts (GRBs) in the northern sky with the IceCube detector in its 22 string configuration active in 2007/2008. The ...searches cover both the prompt and a possible precursor emission as well as a model-independent, wide time window of -1 hr to + 3 hr around each GRB. In contrast to previous searches with a large GRB population, we do not utilize a standard Waxman-Bahcall GRB flux for the prompt emission but calculate individual neutrino spectra for all 41 GRBs from the burst parameters measured by satellites. For all of the three time windows, the best estimate for the number of signal events is zero. Therefore, we place 90% CL upper limits on the fluence from the prompt phase of 3.7 x 10(-3) erg cm(-2) (72 TeV-6.5 PeV) and on the fluence from the precursor phase of 2.3 x 10(-3) erg cm(-2) (2.2-55 TeV), where the quoted energy ranges contain 90% of the expected signal events in the detector. The 90% CL upper limit for the wide time window is 2.7 x 10(-3) erg cm(-2) (3 TeV-2.8 PeV) assuming an E-2 flux.
A search for an excess of muon–neutrinos from neutralino annihilations in the Sun has been performed with the AMANDA-II neutrino detector using data collected in 143.7 days of live-time in 2001. No ...excess over the expected atmospheric neutrino background has been observed. An upper limit at 90% confidence level has been obtained on the annihilation rate of captured neutralinos in the Sun, as well as the corresponding muon flux limit at the Earth, both as functions of the neutralino mass in the range 100–5000
GeV.
Reducing nitrogen pollution while maintaining milk production is a major challenge of dairy production. One of the keys to delivering on this challenge is to improve the efficiency of how dairy cows ...use nitrogen. Thus, estimating the nitrogen utilization of lactating grazing dairy cows and exploring the association between animal factors and productivity with nitrogen utilization are the first steps to understanding the nitrogen utilization complex in dairy cows. Nitrogen utilization metrics were derived from milk and body weight records from 1,291 grazing dairy cows of multiple breeds and crossbreeds; all cows had sporadic information on nitrogen intake concurrent with information on nitrogen sinks (and other nitrogen sources, such as body tissue mobilization). Several nitrogen utilization metrics were investigated, including nitrogen use efficiency (nitrogen output as products such as milk and meat divided by nitrogen intake) and nitrogen excreted (nitrogen intake less the nitrogen output as products such as milk and meat). In the present study, a primiparous Holstein-Friesian used, on average, 20.6% of the nitrogen it ate, excreting the surplus as feces and urine, representing 402 g of nitrogen per day. Intercow variability existed, with a between-cow standard deviation of 0.0094 for nitrogen use efficiency and 24 g of nitrogen per day for nitrogen excretion. As lactation progressed, nitrogen use efficiency declined and nitrogen excretion increased. Nevertheless, nitrogen use efficiency improved (i.e., decreased) from first to second parity, even though it did not improve from second to third parity or greater. Furthermore, nitrogen excretion continued to increase from first to third parity or greater. Nitrogen use efficiency and nitrogen excretion were negatively correlated (-0.56 to -0.40), signifying that dairy cows who partition more of the ingested nitrogen into products such as milk and meat, on average, also excrete less nitrogen. Milk urea nitrogen was, at best, weakly correlated with nitrogen use efficiency and nitrogen excretion; the correlations were between -0.01 and 0.06. In conclusion, several cow-level factors such as parity, stage of lactation, and breed were associated with the range of different nitrogen efficiency metrics investigated; moreover, even after accounting for such effects, 4.8% to 6.3% of the remaining variation in the nitrogen use efficiency and nitrogen balance metrics were attributable to intercow differences.
Runs of homozygosity (ROH) are contiguous lengths of homozygous genotypes that are present in an individual due to parents transmitting identical haplotypes to their offspring. The extent and ...frequency of ROHs may inform on the ancestry of an individual and its population. Here we use high density (n = 777,962) bi-allelic SNPs in a range of cattle breed samples to correlate ROH with the pedigree-based inbreeding coefficients and to validate subsequent analyses using 54,001 SNP genotypes. This study provides a first testing of the inference drawn from ROH through comparison with estimates of inbreeding from calculations based on the detailed pedigree data available for several breeds.
All animals genotyped on the HD panel displayed at least one ROH that was between 1-5 Mb in length with certain regions of the genome more likely to be involved in a ROH than others. Strong correlations (r = 0.75, p < 0.0001) existed between the pedigree-based inbreeding coefficient and a statistic based on sum of ROH of length > 0.5 KB and suggests that in the absence of an animal's pedigree data, the extent of a genome under ROH may be used to infer aspects of recent population history even from relatively few samples.
Our findings suggest that ROH are frequent across all breeds but differing patterns of ROH length and burden illustrate variations in breed origins and recent management.
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