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131.
BackgroundAlthough rare, placental abruption is implicated in disproportionately high rates of perinatal morbidity and mortality. Understanding geographic and temporal variations may provide insights into possible amenable factors of abruption. We examined abruption frequencies by maternal age, delivery year, and maternal birth cohorts over three decades across seven countries.MethodsWomen that delivered in the US (n = 863,879; 1979–10), Canada (4 provinces, n = 5,407,463; 1982–11), Sweden (n = 3,266,742; 1978–10), Denmark (n = 1,773,895; 1978–08), Norway (n = 1,780,271, 1978–09), Finland (n = 1,411,867; 1987–10), and Spain (n = 6,151,508; 1999–12) were analyzed. Abruption diagnosis was based on ICD coding. Rates were modeled using Poisson regression within the framework of an age-period-cohort analysis, and multi-level models to examine the contribution of smoking in four countries.ResultsAbruption rates varied across the seven countries (3–10 per 1000), Maternal age showed a consistent J-shaped pattern with increased rates at the extremes of the age distribution. In comparison to births in 2000, births after 2000 in European countries had lower abruption rates; in the US there was an increase in rate up to 2000 and a plateau thereafter. No birth cohort effects were evident. Changes in smoking prevalence partially explained the period effect in the US (P = 0.01) and Sweden (P<0.01).ConclusionsThere is a strong maternal age effect on abruption. While the abruption rate has plateaued since 2000 in the US, all other countries show declining rates. These findings suggest considerable variation in abruption frequencies across countries; differences in the distribution of risk factors, especially smoking, may help guide policy to reduce abruption rates.  相似文献   
132.
Fishes have been introduced worldwide with deleterious effects on various native ecosystems. To gain insight into this phenomenon in Israel, we studied the introduced ichthyofauna. There are 27 species of introduced fishes in the freshwater habitats of Israel, a large number for a nation this size. Ten of these species reproduce in the wild. Most of these fishes were introduced for aquaculture; some are constantly restocked. The proportion of restocked versus established species in Israel is high compared to other regions. New fish introductions continue in recent decades, unlike the global trend. In Israel these species are found in the Jordan Basin, Lake Kinneret (Sea of Galilee), and the coastal plain rivers. A few species are widespread, and most are found in Lake Kinneret. Harmful effects of introduced fishes have been suspected and in several cases demonstrated. We encourage further caution when new introductions are contemplated; in some regions eradication should be attempted.  相似文献   
133.
The structures of guluronic-acid-rich alginate in the acid and calcium forms were investigated using fiber X-ray diffraction. Data recorded for alginate fibers in the acid form show a repeat along the chain axis of c = 0.87 nm, a value that is in agreement with the one measured by Atkins et al. (Biopolymers 1973, 12, 1865) and contradicts a repeat of 0.78 nm recently suggested by Li et al. (Biomacromolecules 2007, 8, 464). In the Ca2+ form, our observations indicate that the junction zone involves dimerization of polymer chains through Ca2+ coordination according to the egg-box model. For reasons that are not understood at present, coordination of the divalent cations reduces the ability for the lateral crystallographic packing of the dimers. A proposed model for the junction zone involves polymer chains packed on a hexagonal lattice with a lattice constant a = 0.66 nm. Random pairs of chains form dimers through coordination of Ca2+ cations. Further lateral interaction between dimers is mediated by disordered Na+ and Ca2+ cations, water molecules, and hydrogen bonding.  相似文献   
134.
The availability of mannuronan and mannuronan C-5 epimerases allows the production of a strictly alternating mannuronate-guluronate (MG) polymer and the MG-enrichment of natural alginates, providing a powerful tool for the analysis of the role of such sequences in the calcium-alginate gel network. In view of the calcium binding properties of long alternating sequences revealed by circular dichroism studies which leads eventually to the formation of stable hydrogels, their direct involvement in the gel network is here suggested. In particular, 1H NMR results obtained from a mixed alginate sample containing three polymeric species, G blocks, M blocks, and MG blocks, without chemical linkages between the block structures, indicate for the first time the formation of mixed junctions between G and MG blocks. This is supported by the analysis of the Young's modulus of hydrogels from natural and epimerized samples obtained at low calcium concentrations. Furthermore, the "zipping" of long alternating sequences in secondary MG/MG junctions is suggested to account for the shrinking (syneresis) of alginate gels in view of its dependence on the length of the MG blocks. As a consequence, a partial network collapse, macroscopically revealed by a decrease in the Young's modulus, occurred as the calcium concentration in the gel was increased. The effect of such "secondary" junctions on the viscoelastic properties of alginate gels was evaluated measuring their creep compliance under uniaxial compression. The experimental curves, fitted by a model composed of a Maxwell and a Voigt element in series, revealed an increase in the frictional forces between network chains with increasing length of the alternating sequences. This suggests the presence of an ion mediated mechanism preventing the shear of the gel.  相似文献   
135.
New chicken Rfp-Y haplotypes were determined by the use of restriction fragment length polymorphism (RFLP) and mixed lymphocyte culture (MLC) in four different chicken haplotypes, B 15 , B 19 , B 21 , B 201 . The RFLP polymorphism was mapped to the Rfp-Y system by the use of a subclone (18.1) which maps near a polymorphic lectin gene located in the Rfp-Y system and DNA from families with known segregation of the implicated RFLP polymorphism. For the first time it is shown that major histocompatibility complex class II genes in the Rfp-Y system have functional implications. Sequence information of the B1 domain of the proposed Rfp-Y haplotypes was obtained which supported the functional data.  相似文献   
136.
We explored the temporal and spatial variations in airborne Alternaria spore quantitative and phenological features in Europe using 23 sites with annual time series between 3 and 15 years. The study covers seven countries and four of the main biogeographical regions in Europe. The observations were obtained with Hirst-type spore traps providing time series with daily records. Site locations extend from Spain in the south to Denmark in the north and from England in the West to Poland in the East. The study is therefore the largest assessment ever carried out for Europe concerning Alternaria. Aerobiological data were investigated for temporal and spatial patterns in their start and peak season dates and their spore indices. Moreover, the effects of climate were checked using meteorological data for the same period, using a crop growth model. We found that local climate, vegetation patterns and management of landscape are governing parameters for the overall spore concentration, while the annual variations caused by weather are of secondary importance but should not be neglected. The start of the Alternaria spore season varies by several months in Europe, but the peak of the season is more synchronised in central-northern Europe in the middle of the summer, while many southern sites have peak dates either earlier or later than northern Europe. The use of a crop growth model to explain the start and peak of season suggests that such methods could be useful to describe Alternaria seasonality in areas with no available observations.  相似文献   
137.
138.

Background

Globally, Médecins Sans Frontières (MSF) treats more than 300,000 severely malnourished children annually. Malnutrition is not only caused by lack of food but also by illnesses and by poor infant and child feeding practices. Breaking the vicious cycle of illness and malnutrition by providing ill children with nutritional supplementation is a potentially powerful strategy for preventing malnutrition that has not been adequately investigated. Therefore, MSF investigated whether incidence of malnutrition among ill children <5 y old could be reduced by providing a fortified food product or micronutrients during their 2-wk convalescence period. Two trials, one in Nigeria and one in Uganda, were conducted; here, we report on the trial that took place in Kaabong, a poor agropastoral region of Karamoja, in east Uganda. While the region of Karamoja shows an acute malnutrition rate between 8.4% and 11.5% of which 2% to 3% severe malnutrition, more than half (58%) of the population in the district of Kaabong is considered food insecure.

Methods and Findings

We investigated the effect of two types of nutritional supplementation on the incidence of malnutrition in ill children presenting at outpatient clinics during March 2011 to April 2012 in Kaabong, Karamoja region, Uganda, a resource-poor region where malnutrition is a chronic problem for its seminomadic population. A three-armed, partially-blinded, randomised controlled trial was conducted in children diagnosed with malaria, diarrhoea, or lower respiratory tract infection. Non-malnourished children aged 6 to 59 mo were randomised to one of three arms: one sachet/d of ready-to-use therapeutic food (RUTF), two sachets/d of micronutrient powder (MNP), or no supplement (control) for 14 d for each illness over 6 mo. The primary outcome was the incidence of first negative nutritional outcome (NNO) during the 6 mo follow-up. NNO was a study-specific measure used to indicate progression to moderate or severe acute malnutrition; it was defined as weight-for-height z-score <−2, mid-upper arm circumference (MUAC) <115 mm, or oedema, whichever came first.Of the 2,202 randomised participants, 51.2% were girls, and the mean age was 25.2 (±13.8) mo; 148 (6.7%) participants were lost to follow-up, 9 (0.4%) died, and 14 (0.6%) were admitted to hospital. The incidence rates of NNO (first event/year) for the RUTF, MNP, and control groups were 0.143 (95% confidence interval [CI], 0.107–0.191), 0.185 (0.141–0.239), and 0.213 (0.167–0.272), respectively. The incidence rate ratio was 0.67 (95% CI, 0.46–0.98; p = 0.037) for RUTF versus control; a reduction of 33.3%. The incidence rate ratio was 0.86 (0.61–1.23; p = 0.413) for MNP versus control and 0.77 for RUTF versus MNP (95% CI 0.52–1.15; p = 0.200). The average numbers of study illnesses for the RUTF, MNP, and control groups were 2.3 (95% CI, 2.2–2.4), 2.1 (2.0–2.3), and 2.3 (2.2–2.5). The proportions of children who died in the RUTF, MNP, and control groups were 0%, 0.8%, and 0.4%.The findings apply to ill but not malnourished children and cannot be generalised to a general population including children who are not necessarily ill or who are already malnourished.

Conclusions

A 2-wk nutrition supplementation programme with RUTF as part of routine primary medical care to non-malnourished children with malaria, LRTI, or diarrhoea proved effective in preventing malnutrition in eastern Uganda. The low incidence of malnutrition in this population may warrant a more targeted intervention to improve cost effectiveness.

Trial Registration

clinicaltrials.gov NCT01497236  相似文献   
139.

Background

Globally, Médecins Sans Frontières (MSF) treats more than 300,000 severely malnourished children annually. Malnutrition is not only caused by lack of food and poor infant and child feeding practices but also by illnesses. Breaking the vicious cycle of illness and malnutrition by providing ill children with nutritional supplementation is a potentially powerful strategy for preventing malnutrition that has not been adequately investigated. Therefore, MSF investigated whether incidence of malnutrition among ill children <5 y old could be reduced by providing a fortified food product or micronutrients during their 2-wk convalescence period. Two trials, one in Nigeria and one in Uganda, were conducted; here we report on the trial that took place in Goronyo, a rural region of northwest Nigeria with high morbidity and malnutrition rates.

Methods and Findings

We investigated the effect of supplementation with ready-to-use therapeutic food (RUTF) and a micronutrient powder (MNP) on the incidence of malnutrition in ill children presenting at an outpatient clinic in Goronyo during February to September 2012. A three-armed, partially-blinded, randomised controlled trial was conducted in children diagnosed as having malaria, diarrhoea, or lower respiratory tract infection. Children aged 6 to 59 mo were randomised to one of three arms: one sachet/d of RUTF; two sachets/d of micronutrients or no supplement (control) for 14 d for each illness over 6 mo. The primary outcome was the incidence of first negative nutritional outcome (NNO) during the 6 mo follow-up. NNO was a study-specific measure used to indicate occurrence of malnutrition; it was defined as low weight-for-height z-score (<−2 for non-malnourished and <−3 for moderately malnourished children), mid-upper arm circumference <115 mm, or oedema, whichever came first.Of the 2,213 randomised participants, 50.0% were female and the mean age was 20.2 (standard deviation 11.2) months; 160 (7.2%) were lost to follow-up, 54 (2.4%) were admitted to hospital, and 29 (1.3%) died. The incidence rates of NNO for the RUTF, MNP, and control groups were 0.522 (95% confidence interval (95% CI), 0.442–0.617), 0.495 (0.415–0.589), and 0.566 (0.479–0.668) first events/y, respectively. The incidence rate ratio was 0.92 (95% CI, 0.74–1.15; p = 0.471) for RUTF versus control; 0.87 (0.70–1.10; p = 0.242) for MNP versus control and 1.06 (0.84–1.33, p = 0.642) for RUTF versus MNP. A subgroup analysis showed no interaction nor confounding, nor a different effectiveness of supplementation, among children who were moderately malnourished compared with non-malnourished at enrollment. The average number of study illnesses for the RUTF, MNP, and control groups were 4.2 (95% CI, 4.0–4.3), 3.4 (3.2–3.6), and 3.6 (3.4–3.7). The proportion of children who died in the RUTF, MNP, and control groups were 0.8% (95% CI, 0.3–1.8), 1.8% (1.0–3.3), and 1.4% (0.7–2.8).

Conclusions

A 2-wk supplementation with RUTF or MNP to ill children as part of routine primary medical care did not reduce the incidence of malnutrition. The lack of effect in Goronyo may be due to a high frequency of morbidity, which probably further affects a child’s nutritional status and children’s ability to escape from the illness–malnutrition cycle. The duration of the supplementation may have been too short or the doses of the supplements may have been too low to mitigate the effects of high morbidity and pre-existing malnutrition. An integrated approach combining prevention and treatment of diseases and treatment of moderate malnutrition, rather than prevention of malnutrition by nutritional supplementation alone, might be more effective in reducing the incidence of acute malnutrition in ill children.

Trial Registration

clinicaltrials.gov NCT01154803  相似文献   
140.
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