922 resultados para Julian date of birth
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The present study was carried out with the objective of evaluating the effects of feeding dairy cows with organic or inorganic sources of zinc (Zn), copper (Cu) and selenium (Se) on blood concentrations of these minerals, blood metabolic profiles, nutrient intake and milk yield and composition. Nineteen Holstein cows were selected and randomly assigned to two groups for receiving organic (n = 9) or inorganic (n = 10) sources of Zn, Cu and Se from 60 days before the expected date of calving to 80 days of lactation. Samples of feed, orts and milk were collected for analysis. Body condition score (BCS) was determined and blood samples were collected for analysis of Zn, Cu and Se concentrations, as well as for metabolic profile. Supplying organic or inorganic sources of Zn, Cu, and Se did not affect dry matter and nutrient intake, blood metabolic profile, milk yield and composition, plasma concentration of these minerals, and BCS or change the BCS in cows from 60 days before the expected date of calving to 80 days of lactation. An effect of time was observed on all feed intake variables, plasma concentrations of Zn and Se, milk yield, milk protein content, BCS and change in BCS.
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The global distribution of bat taxa indicates that the Atlantic and Pacific Oceans are effective barriers to movement between the Old and New Worlds. For instance, one of the major suborders, Yinpterochiroptera, has an exclusively Old World distribution, and within the other, Yangochiroptera, no species and only five genera are common to both. However, as bats are sometimes blown out to sea, and have colonised isolated islands, occasional natural movement between the New and Old Worlds does appear to be possible. Here we identify new genotypes of a blood parasite, Trypanosoma dionisii, in Old World bats that are closely related to South American strains. Using highly conservative calibration points, divergence of Old and New World strains is estimated to have occurred 3.2-5.0 million years ago (MYA), depending on the method used (upper 95% CL for maximum time 11.4 MYA). The true date of divergence is likely to be considerably more recent. These results demonstrate that taxon-specific parasites can indicate historical movements of their hosts, even where their hosts may have left no lasting phylogenetic footprint. (C) 2012 Elsevier Inc. All rights reserved.
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The objective of this work was to assess the degree of multicollinearity and to identify the variables involved in linear dependence relations in additive-dominant models. Data of birth weight (n=141,567), yearling weight (n=58,124), and scrotal circumference (n=20,371) of Montana Tropical composite cattle were used. Diagnosis of multicollinearity was based on the variance inflation factor (VIF) and on the evaluation of the condition indexes and eigenvalues from the correlation matrix among explanatory variables. The first model studied (RM) included the fixed effect of dam age class at calving and the covariates associated to the direct and maternal additive and non-additive effects. The second model (R) included all the effects of the RM model except the maternal additive effects. Multicollinearity was detected in both models for all traits considered, with VIF values of 1.03 - 70.20 for RM and 1.03 - 60.70 for R. Collinearity increased with the increase of variables in the model and the decrease in the number of observations, and it was classified as weak, with condition index values between 10.00 and 26.77. In general, the variables associated with additive and non-additive effects were involved in multicollinearity, partially due to the natural connection between these covariables as fractions of the biological types in breed composition.
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AIM: The purpose of the present study was to analyze the relationship between root formation of the first premolars and skeletal maturation stages identified in hand-wrist radiographs. METHODS: A cross-sectional study was carried out involving the panoramic and hand-wrist radiographs obtained on the same date of 232 patients, 123 boys and 109 girls aged 4 years and 5 months to 17 years and 12 months. Root formation stages of the first premolars were related to the ossification stages of the sesamoid bone, epiphyseal stages of the phalanx of the thumb and epiphyseal stages of the radius. RESULTS: The studied variables demonstrated statistically significant correlations. CONCLUSION: Roots of the lower first premolars do not reach 2/3 of their complete length before adolescence.
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[EN] This crab was captured in the whole range of depths sampled, although its highest abundance was found between 600 and 800 m, on muddy-rocky bottoms. Moreover, significant differences were observed in the average weight and length, according to depth of capture, island of origin, and date of survey. In general, the b parameter of length-weight relationship indicates a negative allometric growth pattern, although in some cases it was not statistically different from isometry, particularly in males. Males were heavier, larger, and more abundant in catches than females.
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The Gulf of Aqaba represents a small scale, easy to access, regional analogue of larger oceanic oligotrophic systems. In this Gulf, the seasonal cycles of stratification and mixing drives the seasonal phytoplankton dynamics. In summer and fall, when nutrient concentrations are very low, Prochlorococcus and Synechococcus are more abundant in the surface water. This two populations are exposed to phosphate limitation. During winter mixing, when nutrient concentrations are high, Chlorophyceae and Cryptophyceae are dominant but scarce or absent during summer. In this study it was tried to develop a simulation model based on historical data to predict the phytoplankton dynamics in the northern Gulf of Aqaba. The purpose is to understand what forces operate, and how, to determine the phytoplankton dynamics in this Gulf. To make the models data sampled in two different sampling station (Fish Farm Station and Station A) were used. The data of chemical, biological and physical factors, are available from 14th January 2007 to 28th December 2009. The Fish Farm Station point was near a Fish Farm that was operational until 17th June 2008, complete closure date of the Fish Farm, about halfway through the total sampling time. The Station A sampling point is about 13 Km away from the Fish Farm Station. To build the model, the MATLAB software was used (version 7.6.0.324 R2008a), in particular a tool named Simulink. The Fish Farm Station models shows that the Fish Farm activity has altered the nutrient concentrations and as a consequence the normal phytoplankton dynamics. Despite the distance between the two sampling stations, there might be an influence from the Fish Farm activities also in the Station A ecosystem. The models about this sampling station shows that the Fish Farm impact appears to be much lower than the impact in the Fish Farm Station, because the phytoplankton dynamics appears to be driven mainly by the seasonal mixing cycle.
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The last decade has witnessed the establishment of a Standard Cosmological Model, which is based on two fundamental assumptions: the first one is the existence of a new non relativistic kind of particles, i. e. the Dark Matter (DM) that provides the potential wells in which structures create, while the second one is presence of the Dark Energy (DE), the simplest form of which is represented by the Cosmological Constant Λ, that sources the acceleration in the expansion of our Universe. These two features are summarized by the acronym ΛCDM, which is an abbreviation used to refer to the present Standard Cosmological Model. Although the Standard Cosmological Model shows a remarkably successful agreement with most of the available observations, it presents some longstanding unsolved problems. A possible way to solve these problems is represented by the introduction of a dynamical Dark Energy, in the form of the scalar field ϕ. In the coupled DE models, the scalar field ϕ features a direct interaction with matter in different regimes. Cosmic voids are large under-dense regions in the Universe devoided of matter. Being nearby empty of matter their dynamics is supposed to be dominated by DE, to the nature of which the properties of cosmic voids should be very sensitive. This thesis work is devoted to the statistical and geometrical analysis of cosmic voids in large N-body simulations of structure formation in the context of alternative competing cosmological models. In particular we used the ZOBOV code (see ref. Neyrinck 2008), a publicly available void finder algorithm, to identify voids in the Halos catalogues extraxted from CoDECS simulations (see ref. Baldi 2012 ). The CoDECS are the largest N-body simulations to date of interacting Dark Energy (DE) models. We identify suitable criteria to produce voids catalogues with the aim of comparing the properties of these objects in interacting DE scenarios to the standard ΛCDM model, at different redshifts. This thesis work is organized as follows: in chapter 1, the Standard Cosmological Model as well as the main properties of cosmic voids are intro- duced. In chapter 2, we will present the scalar field scenario. In chapter 3 the tools, the methods and the criteria by which a voids catalogue is created are described while in chapter 4 we discuss the statistical properties of cosmic voids included in our catalogues. In chapter 5 the geometrical properties of the catalogued cosmic voids are presented by means of their stacked profiles. In chapter 6 we summarized our results and we propose further developments of this work.
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Purpose To evaluate geriatric assessment (GA) domains in relation to clinically important outcomes in older breast cancer survivors. Methods Six hundred sixty women diagnosed with primary breast cancer in four US geographic regions (Los Angeles, CA; Minnesota; North Carolina; and Rhode Island) were selected with disease stage I to IIIA, age ≥ 65 years at date of diagnosis, and permission from attending physician to contact. Data were collected over 7 years of follow-up from consenting patients' medical records, telephone interviews, physician questionnaires, and the National Death Index. Outcomes included self-reported treatment tolerance and all-cause mortality. Four GA domains were described by six individual measures, as follows: sociodemographic by adequate finances; clinical by Charlson comorbidity index (CCI) and body mass index; function by number of physical function limitations; and psychosocial by the five-item Mental Health Index (MHI5) and Medical Outcomes Study Social Support Survey (MOS-SSS). Associations were evaluated using t tests, χ2 tests, and regression analyses. Results In multivariable regression including age and stage, three measures from two domains (clinical and psychosocial) were associated with poor treatment tolerance; these were CCI ≥ 1 (odds ratio [OR] = 2.49; 95% CI, 1.18 to 5.25), MHI5 score less than 80 (OR = 2.36; 95% CI, 1.15 to 4.86), and MOS-SSS score less than 80 (OR = 3.32; 95% CI, 1.44 to 7.66). Four measures representing all four GA domains predicted mortality; these were inadequate finances (hazard ratio [HR] = 1.89; 95% CI, 1.24 to 2.88; CCI ≥ 1 (HR = 1.38; 95% CI, 1.01 to 1.88), functional limitation (HR = 1.40; 95% CI, 1.01 to 1.93), and MHI5 score less than 80 (HR = 1.34; 95% CI, 1.01 to 1.85). In addition, the proportion of women with these outcomes incrementally increased as the number of GA deficits increased. Conclusion This study provides longitudinal evidence that GA domains are associated with poor treatment tolerance and predict mortality at 7 years of follow-up, independent of age and stage of disease.
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Thoracic endovascular aortic repair (TEVAR) has emerged as a promising therapeutic alternative to conventional open aortic replacement but it requires suitable proximal and distal landing zones for stent-graft anchoring. Many aortic pathologies affect in the immediate proximity of the left subclavian artery (LSA) limiting the proximal landing zone site without proximal vessel coverage. In patients in whom the distance between the LSA and aortic lesion is too short, extension of the landing zone can be obtained by covering the LSA's origin with the endovascular stent graft (ESG). This manoeuvre has the potential for immediate and delayed neurological and vascular symptoms. Some authors, therefore, propose prophylactic revascularisation of the LSA by transposition or bypass, while others suggest prophylactic revascularisation only under certain conditions, and still others see no requirement for prophylactic revascularisation in anticipation of LSA ostium coverage. In this review about LSA revascularisation in TEVAR patients with coverage of the LSA, we searched the electronic databases MEDLINE and EMBASE historically until the end date of May 2010 with the search terms left subclavian artery, covering, endovascular, revascularisation and thoracic aorta. We have gathered the most complete scientific evidence available used to support the various concepts to deal with this issue. After a review of the current available literature, 23 relevant articles were found, where we have identified and analysed three basic treatment concepts for LSA revascularisation in TEVAR patients (prophylactic, conditional prophylactic and no prophylactic LSA revascularisation). The available evidence supports prophylactic revascularisation of the LSA before ESG LSA coverage when preoperative imaging reveals abnormal supra-aortic vascular anatomy or pathology. We further conclude that elective patients undergoing planned coverage of the LSA during TEVAR should receive prophylactic LSA transposition or LSA-to-left-common-carotid-artery (LCCA) bypass surgery to prevent severe neurological complications, such as paraplegia or brain stem infarction.
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White-nose syndrome (WNS), an emerging infectious disease that has killed over 5.5 million hibernating bats, is named for the causative agent, a white fungus (Geomyces destructans (Gd)) that invades the skin of torpid bats. During hibernation, arousals to warm (euthermic) body temperatures are normal but deplete fat stores. Temperature-sensitive dataloggers were attached to the backs of 504 free-ranging little brown bats (Myotis lucifugus) in hibernacula located throughout the northeastern USA. Dataloggers were retrieved at the end of the hibernation season and complete profiles of skin temperature data were available from 83 bats, which were categorized as: (1) unaffected, (2) WNS-affected but alive at time of datalogger removal, or (3) WNS-affected but found dead at time of datalogger removal. Histological confirmation of WNS severity (as indexed by degree of fungal infection) as well as confirmation of presence/absence of DNA from Gd by PCR was determined for 26 animals. We demonstrated that WNS-affected bats aroused to euthermic body temperatures more frequently than unaffected bats, likely contributing to subsequent mortality. Within the subset of WNS-affected bats that were found dead at the time of datalogger removal, the number of arousal bouts since datalogger attachment significantly predicted date of death. Additionally, the severity of cutaneous Gd infection correlated with the number of arousal episodes from torpor during hibernation. Thus, increased frequency of arousal from torpor likely contributes to WNS-associated mortality, but the question of how Gd infection induces increased arousals remains unanswered.
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Background Meadows are regularly mown in order to provide fodder or litter for livestock and to prevent vegetation succession. However, the time of year at which meadows should be first mown in order to maximize biological diversity remains controversial and may vary with respect to context and focal taxa. We carried out a systematic review and meta-analysis on the effects of delaying the first mowing date upon plants and invertebrates in European meadowlands. Methods Following a CEE protocol, ISI Web of Science, Science Direct, JSTOR, Google and Google Scholar were searched. We recorded all studies that compared the species richness of plants, or the species richness or abundance of invertebrates, between grassland plots mown at a postponed date (treatment) vs plots mown earlier (control). In order to be included in the meta-analysis, compared plots had to be similar in all management respects, except the date of the first cut that was (mostly experimentally) manipulated. They were also to be located in the same meadow type. Meta-analyses applying Hedges’d statistic were performed. Results Plant species richness responded differently to the date to which mowing was postponed. Delaying mowing from spring to summer had a positive effect, while delaying either from spring to fall, or from early summer to later in the season had a negative effect. Invertebrates were expected to show a strong response to delayed mowing due to their dependence on sward structure, but only species richness showed a clearly significant positive response. Invertebrate abundance was positively influenced in only a few studies. Conclusions The present meta-analysis shows that in general delaying the first mowing date in European meadowlands has either positive or neutral effects on plant and invertebrate biodiversity (except for plant species richness when delaying from spring to fall or from early summer to later). Overall, there was also strong between-study heterogeneity, pointing to other major confounding factors, the elucidation of which requires further field experiments with both larger sample sizes and a distinction between taxon-specific and meadow-type-specific responses.
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Psychogenetic research has emphasised the influence of social factors on a child's intellectual development. In her work, Ms. Dumitrascu examines two such factors; family size and order of birth. However, since these formal parameters tend to be unstable, other more informal factors should be taken into consideration. Of these, perhaps the most interesting is the "style" of parental education, which Ms. Dumitrascu regards as an expression of national traditions at the family level. This educational style is culture dependent. Only a comparative, cross-cultural study can reveal the real mechanism through which educational style influences the development of a child's intellect and personality. Ms. Dumitrascu conducted an experimental cross-cultural study aimed at examining the effects of the family environment on a child's intellectual development. Three distinct populations were involved in her investigation, each having quite a distinct status in their geographical area; Romanians, Romanies (Gypsies) from Romania, and Russians from the Republic of Moldova. She presented her research in the form of a series of articles written in English totalling 85 pages, and also on disc. A significant difference was revealed between the intelligence of a child living in a large family, and that of a child with no brothers or sisters. In the case of Romany children, the gap is remarkably large. Ms. Dumitrascu concludes that the simultaneous action of several negative factors (low socio-economic status, large family size, socio-cultural isolation of a population) may delay child development. Subjected to such a precarious environment, Romany children do not seek self-realisation, but rather struggle to survive the hardship. Most of them remain out of civilisation. Unfortunately, adult Romanies seldom express any concern regarding their children's successful social integration. The school as main socialisation tool has no value for most parents. Ms. Dumitrascu argues the need for a major effort aimed at helping Romany's social integration. She hopes this project will be of some help for psychologists, social workers, teachers, and all those who are interested in the integration into society of minority groups.
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OBJECTIVE: To determine whether the virulence of HIV-1 has been changing since its introduction into Switzerland. DESIGN: A prospective cohort study of HIV-1 infected individuals with well-characterized pre-therapy disease history. METHODS: To minimize the effect of recently imported viruses and ethnicity-associated host factors, the analysis was restricted to the white, north-west-European majority population of the cohort. Virulence was characterized by the decline slope of the CD4 cell count (n = 817 patients), the decline slope of the CD4:CD8 ratio (n = 815 patients) and the viral setpoint (n = 549 patients) in untreated patients with sufficient data points. Linear regression models were used to detect correlations between the date of diagnosis (ranging between 1984 and 2003) and the virulence markers, controlling for gender, exposure category, age and CD4 cell count at entry. RESULTS: We found no correlation between any of the virulence markers and the date of diagnosis. Inspection of short-term trends confirmed that virulence has fluctuated around a stable level over time. CONCLUSIONS: The lack of long-term time trends in the virulence markers indicates that HIV-1 is not evolving towards increasing or decreasing virulence at a perceptible rate. Both highly virulent and attenuated strains have apparently been unable to spread at the population level. This result suggests that either the evolution of virulence may be slow or inhibited due to evolutionary constraints, or HIV-1 may have already evolved to optimal virulence in the human host.
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BACKGROUND: We hypothesized that certain patient characteristics have different effects on the risk of early stem loosening in total hip arthroplasty (THA). We therefore conducted a case-control study using register-database records with the aim of identifying patient-specific risk factors associated with radiographic signs of aseptic loosening of the femoral component in THA. METHOD: Data were derived from a multinational European registry and were collected over a period of 25 years. 725 cases with radiographic signs of stem loosening were identified and matched to 4,310 controls without any signs of loosening. Matching criteria were type of implant, size of head, date of operation, center of primary intervention, and follow-up time. The risk factors analyzed were age at operation, sex, diagnosis and previous ipsilateral operations, height, weight, body mass index and mobility based on the Charnley classification. RESULTS: Women showed significantly lower risk of radiographic loosening than men (odds ratio (OR) 0.64). Age was also a strong factor: risk decreased by 1.8% for each additional year of age at the time of surgery. Height and weight were not associated with risk of loosening. A higher body mass index, however, increased the risk of stem loosening to a significant extent (OR 1.03) per additional unit of BMI. Charnley Class B, indicating restricted mobility, was associated with lower risk of loosening (OR 0.78). INTERPRETATION: An increased activity level, as seen in younger patients and those with unrestricted mobility, is an important factor in the etiology of stem loosening. If combined with high BMI, the risk of stem loosening within 10 years is even higher. A younger person should not be denied the benefits of a total hip arthroplasty but must accept that the risk of future failure is increased.
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In natural history studies of chronic disease, it is of interest to understand the evolution of key variables that measure aspects of disease progression. This is particularly true for immunological variables in persons infected with the Human Immunodeficiency Virus (HIV). The natural timescale for such studies is time since infection. However, most data available for analysis arise from prevalent cohorts, where the date of infection is unknown for most or all individuals. As a result, standard curve fitting algorithms are not immediately applicable. Here we propose two methods to circumvent this difficulty. The first uses repeated measurement data to provide information not only on the level of the variable of interest, but also on its rate of change, while the second uses an estimate of the expected time since infection. Both methods are based on the principal curves algorithm of Hastie and Stuetzle, and are applied to data from a prevalent cohort of HIV-infected homosexual men, giving estimates of the average pattern of CD4+ lymphocyte decline. These methods are applicable to natural history studies using data from prevalent cohorts where the time of disease origin is uncertain, provided certain ancillary information is available from external sources.