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Vitamin D (VD) deficiency has been linked to increased incidence and morbidity of tuberculosis (TB). Chile has large variations in solar radiation (SR; a proxy of VD status) and high prevalence of VD deficiency in its southernmost regions with low SR. We investigated the correlation between regional SR and rates of TB incidence, admissions and deaths in Chile by reviewing national records on prospectively collected mandatory disease notifications, admissions and mortality between 2001 and 2011. Over the study period, 26 691 new TB notifications were registered. The TB incidence rate was 14·77 (95% confidence intervals (CIs) 14·60–14·95), admission rate was 12·12 (95% CI 11·96–12·28) and mortality rate was 1·61 (95% CI 1·55–1·67) per 100 000 population per year. Multivariable linear regressions adjusting for significant demographic TB risk factors in Chile (regional prevalence of HIV infection, rates of migration from TB-endemic countries and rates of imprisonment) revealed an independent and highly statistically significant inverse association between SR and TB incidence rate (β −1·05, 95% CI −1·73 to −0·36, P = 0·007), admission rate (β −1·58, 95% CI −2·23 to −0·93, P < 0·001), and mortality rate (β −0·15, 95% CI −0·23 to −0·07, P = 0·002). These findings support a potential pathogenic role of VD deficiency in TB incidence and severity.
Cannabis use and misuse have become a public health problem. There is a need for reliable screening and assessment tools to identify harmful cannabis use at an early stage. We conducted a systematic review of published instruments used to screen and assess cannabis use disorders.
We included papers published until January 2013 from seven different databases, following the PRISMA guidelines and a predetermined set of criteria for article selection. Only tools including a quantification of cannabis use and/or a measurement of the severity of dependence were considered.
We identified 34 studies, of which 25 included instruments that met our inclusion criteria: 10 scales to assess cannabis use disorders, seven structured interviews, and eight tools to quantify cannabis use. Both cannabis and substance use scales showed good reliability and were validated in specific populations. Structured interviews were also reliable and showed good validity parameters. Common limitations were inadequate time-frames for screening, lack of brevity, undemonstrated validity for some populations (e.g. psychiatric patients, female gender, adolescents), and lack of relevant information that would enable routine use (e.g. risky use, regular users). Instruments to quantify consumption did not measure grams of the psychoactive compounds, which hampered comparability among different countries or regions where tetrahydrocannabinol concentrations may differ.
Current instruments available for assessing cannabis use disorders need to be further improved. A standard cannabis unit should be studied and existing instruments should be adapted to this standard unit in order to improve cannabis use assessment.
WEAVE, the next-generation spectroscopic facility for the WHT, is being built with Gaia support as a central science case. WEAVE is a π-square degree multi-fibre system capable of deploying either 1000 single-fibre probes, 20 mini-IFUs or a single large IFU, to feed a two-arm bench spectrograph. With two spectral resolution modes, main products in support of Gaia will be 1–2 km s−1 accuracy radial velocities in the range 16 < V < 20, and abundances of individual elements to ∼0.1 dex up to V ∼ 17. WEAVE will be used to carry out massive surveys that exploit Gaia data in topics of Milky Way astronomy and stellar evolution.
Differential gene expression analyses typically focus on departures across mathematical expectations (i.e. mean) from two or more groups of microarrays, without considering alternative patterns of departure. Nevertheless, recent studies in humans and great apes have suggested that differential gene expression could also be characterized in terms of heterogeneous dispersion patterns. This must be viewed as a very interesting genetic phenomenon clearly linked to the regulation mechanisms of gene transcription. Unfortunately, we completely lack information about the incidence and relevance of dispersion-specific differential gene expression in livestock species, although a specific Bayes factor (BF) for testing this kind of differential gene expression (i.e. within-probe heteroskedasticity) has been recently developed. Within this context, our main objective was to characterize the incidence of dispersion-specific differential gene expression in pigs and, if possible, providing the first evidence of this phenomenon in a livestock species. We evaluated dispersion-specific differential gene expression on ovary, uterus and hypophysis samples from 22 F2 Iberian × Meishan sows, where a total of 15 252 probes were interrogated. For each tissue, heteroskedasticity of probe-specific residual variances was evaluated by three pairwise comparisons involving three physiological stages, that is, heat, 15 days of pregnancy and 45 days of pregnancy. Between 2.9% and 37.4% of the analyzed probes provided statistical evidence of within-tissue across-physiological stages dispersion-specific differential gene expression (BF >1), and between 0.1% and 3.0% of them reported decisive evidence (BF >100). It is important to highlight that <8% of the heteroskedastic probes were also linked to differential gene expression in terms of departures among the probe-specific mathematical expectation of each physiological stage. This discarded the disturbance of scale effects in a high percentage of probes and suggested that probe-specific heteroskedasticity must be viewed as an independent phenomenon within the context of differential gene expression. As a whole, our results report a remarkable incidence of dispersion-specific differential gene expression across the whole genome of the pig, establishing a very interesting starting point for further studies focused on deciphering the genetic mechanisms underlying heteroskedasticity.
Some recent observations seem to disagree with hierarchical theories of galaxy formation on the role of major mergers in a late build-up of massive early-type galaxies. We re-address this question by analysing the morphology, structural distortion level, and star formation enhancement of a sample of massive galaxies (M* > 5 × 1010M⊙) lying on the Red Sequence and its surroundings at 0.3 < z < 1.5. We have used an initial sample of ~1800 sources with Ks < 20.5 mag over an area ~155 arcmin2 on the Groth Strip, combining data from the Rainbow Extragalactic Database and the GOYA Survey. Red galaxy classes that can be directly associated to intermediate stages of major mergers and to their final products have been defined. For the first time we report observationally the existence of a dominant evolutionary path among massive red galaxies at 0.6 < z < 1.5, consisting in the conversion of irregular disks into irregular spheroids, and of these ones into regular spheroids. This result points to: 1) the massive red regular galaxies at low redshifts derive from the irregular ones populating the Red Sequence and its neighbourhood at earlier epochs up to z ~ 1.5; 2) the progenitors of the bulk of present-day massive red regular galaxies have been blue disks that have migrated to the Red Sequence majoritarily through major mergers at 0.6 < z < 1.2 (these mergers thus starting at z ~ 1.5); 3) the formation of E-S0's that end up with M* > 1011M⊙ at z = 0 through gas-rich major mergers has frozen since z ~ 0.6. Our results support that major mergers have played the dominant role in the definitive build-up of present-day E-S0's with M* > 1011M⊙ at 0.6 < z < 1.2, in good agreement with the hierarchical scenario proposed in the Eliche-Moral et al. (2010a) model (see also Eliche-Moral et al. 2010b). This study is published in Prieto et al. (2012).
Supported by the Spanish Ministry of Science and Innovation (MICINN) under projects AYA2009-10368, AYA2006-12955, AYA2010-21887-C04-04, and AYA2009-11137, by the Madrid Regional Government through the AstroMadrid Project (CAM S2009/ESP-1496), and by the Spanish MICINN under the Consolider-Ingenio 2010 Program grant CSD2006-00070: “First Science with the GTC” (http://www.iac.es/consolider-ingenio-gtc/). S. D. H. & G.
Bacitracin is an antibiotic used in rabbit husbandry to control microbial digestive pathologies. Collateral effects on absorption and mucosal development have been reported and these may impact on protein metabolism. This study aims to analyse the effect of the antibiotic on protein synthesis in lactating does because mammary gland metabolism and milk output should provide a sensitive index of any undesirable action of bacitracin. Rates of protein synthesis were measured in mammary gland, liver, intestinal mucosa and muscle of lactating rabbits does by injecting a flooding dose of [2H5]phenylalanine into the auricular artery of two groups (each n = 8) of New Zealand White does fed different experimental diets. The control group (C) received the basal diet and the bacitracin group (B) ingested the same diet but supplemented with bacitracin (100 mg/kg). Animals received the experimental diet from day 28 of pregnancy until day 26 of lactation when they were slaughtered. Just after birth, litter size was adjusted by cross-fostering either to five or nine pups (four does per dietary treatment). The relative weight of the liver tended to be greater in those females receiving the B diet (27 v. 22.5 g/kg BW; P < 0.07), while diet did not affect mammary gland weight (255.7 ± 10.59 g). Fractional protein synthesis rate (FSR) was higher for intestinal mucosa (duodenum; 51.7% ± 2.09%/day) followed by mammary gland and liver (38.29 ± 2.62%/day and 40.2 ± 1.98%/day, respectively), and the lowest value was observed in muscle (2.92 ± 0.26%/day; P < 0.0001). Bacitracin treatment lowered FSR in the mammary gland by 23% (P = 0.024) and this was independent of litter size. Conversely, FSR in the duodenum was not affected by antibiotic treatment but reduced by 15% (P = 0.021) for the larger litter size.
We perform a sample of N-body simulations of a minor merger between a Milky Way type galaxy and a satellite, which is density scaled version of the primary galaxy. In this suite of collisionless runs we change the value of some critical parameters like the luminous mass ratio between the two galaxies (1 : 6, 1 : 9), the type of orbit (direct or prograde) and the number of particles (185,000, 555,000 and 1,850,000). We estimate the disc thickening by measuring the median of the vertical scale and we find that that the merger increases the scale height in a factor of ≈2 in all the remnants.
To determine the endogenous contribution of purine derivatives (PD) to renal excretion and the urinary recovery of duodenal purine bases (PB), five dairy Granadina goats (initial weight ± s.e.: 38.6 ± 2.78 kg) were each fitted with a duodenal infusion catheter. Animals were offered ad libitum a mixed diet (75 : 25; alfalfa hay : concentrate), which was supplied in equal portions every 3 h. To label microbial PB, (15NH4)2SO4 was added to the concentrate. The lower enrichment of urinary PD (15N-allantoin) compared with duodenal PB enrichment confirmed the presence of an endogenous PD fraction (268.5 ± 21.98 μmol/kg weight0.75 or 0.386 of the total PD excretion). The recovery of PD in urine and milk increased linearly in response to increasing amounts of duodenally infused RNA (starting on day 21 after parturition). On average, 0.74 of infused PB from RNA was recovered in urine. Milk PD constituted a minor (<0.01) fraction of the total PD excretion and this fraction decreased as the amount of infused PB increased. Our findings indicate that lactation in goats did not affect the urinary recovery of duodenal PB but increased the endogenous contribution to urinary excretion of PD.
The bulge contribution to the inner density profile of a galaxy is well traced by the bulge's NIR surface brightness profile. We map the surface brightness profiles of bulges using HST/NICMOS imaging. Most bulges show nuclear components of 20–200 pc scales, and frequently also unresolved nuclear star clusters (<20 pc). These nuclear components are the densest parts of bulges, and gave bulges the “reputation” of having high stellar concentration. Actually, the Sérsic r1/n bulges typically have low concentrations, 1 < n < 2.5.
We cannot confirm the bi-modal distribution of bulge profile slopes reported by others, and suggest that the alleged bi-modality is related to selectively excluding/including nuclear components in low/high-n bulges.
Modern kinematic diagnostics from high-S/N spectroscopy provide useful tests on the collisionless merger hypothesis for the formation of elliptical galaxies. Bender, Saglia & Gerhard (1994) show that the skewness of the line-of-sight velocity distributions (LOSVD) has opposite sign to the rotation velocity and follows a distinct pattern. Previous N-body experiments (Bendo & Barnes 2000, Naab & Burkert 2001) disagree as to whether the relation is reproduced by the models.
We present first results from an ongoing effort to explain the skewness properties of the LOSVD's of ellipticals. We use large N-body simulations of disk-disk galaxy mergers ($10^6$ particles), with mass ratios 1:1 and 3:1. Our 1:1 models fail to reproduce the H3 vs. $V/\sigma$ relation, in agreement with Naab & Burkert (2001). 3:1 mergers yield trends similar to the observations for large values of $V/\sigma$, but with overall lower H3 values in the models than in real galaxies. And we fail to reproduce high H3 values for low $V/\sigma$. So far, it is unclear whether the disagreement is related to the lack of rotation in the bulge components of our initial model galaxies, or to a more general shortcoming of dissipationless mergers to reproduce the properties of real ellipticals.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html
Twenty-eight lactating ewes (mean 48 (s.e. 0·37) kg live weight) were used from days 12 to 52 after lambing to evaluate the effects on digestibility and production performance of replacing barley grain with citrus pulp in diets based on ammonia-treated barley straw. Concentrates included 0·82 to 0·83 of different barley to citrus pulp proportions: 100: 0 (T1); 66: 33 (T2); 33: 66 (T3) and 0: 100 (T4), 0·115 of soya-bean meal, and urea to make diets isonitrogenous. Ewes were adapted to a common diet for 11 days after lambing, and then were given 850 g/day of each experimental concentrate together with 850 g/day of chopped barley straw for 14 days and milk production and lamb growth were recorded. During the following 14 days ewes received the same amount of concentrate but the straw was offered ad libitum and straw intake was recorded as well as milk production and lamb growth. After completing both periods, four ewes per treatment were used for total collections of faeces and urine. Apparent digestibility of organic matter and neutral-detergent fibre increased linearly (P < 0·05) with increasing levels of citrus pulp although no differences were found in the digestible organic matter content of dry matter of diets because of differences in ash content. Urinary excretion of allantoin and purine derivatives per unit of digestible organic matter intake tended to decrease with increasing inclusion of citrus pulp (proportionately by 0·15), suggesting a decrease in microbial protein synthesis, though this effect was not significant (P > 0·05). Faecal excretion of purine bases also decreased (P < 0·05) as citrus pulp inclusion increased. No treatment effect (P > 0·05) on ewe live weight, milk composition or serum glucose and 3–OH butyrate was observed when a 1: 1 straw to concentrate ratio was given, but milk production and lamb daily gain decreased linearly (P < 0·05) with increased proportions of citrus pulp in the concentrate. Similar responses were detected when straw was given ad libitum and differences among treatments in terms of straw intake were not identified. It is concluded that a lower microbial protein flow might explain in part the reduction in milk production observed when barley was replaced with citrus pulp.
Recent progress on the structure and dynamics of bulges is reviewed.
Those aspects that link galaxy bulges either to oblate spheroids akin to
elliptical galaxies or to rapidly-rotating, flattened systems more nearly
resembling the products of disk internal transformations, are highlighted. The
analysis of surface brightness profiles derived from HST data is reviewed to
show that unresolved nuclear components detected by HST have biased the
determination of surface brightness profiles obtained from the ground; r1/4 profiles are virtually nonexistent in galaxy
bulges. Predictions from accretion N-body models on the shape of surface
brightness profiles are discussed. The position of bulges on the Fundamental
Plane (FP) of elliptical galaxies is examined to infer clues on bulge
population ages and bulge dynamical structure. Kinematic diagnostics on the
internal dynamics of bulges are examined. Finally, a new approach to the
kinematic analysis of galaxies, based on the use of synthetic spectra of single
stellar population models instead of the standard stellar templates, is
The present study compares estimates of caecotrophes production from urinary purine derivatives (PD) excretion with that from preventing caecotrophy by using a neck collar. A total of 64 New Zealand growing male rabbits were used to study the effect of diet composition on caecotrophes production. Diets were formulated using two sources of structural carbohydrates (fibre): alfalfa hay (AH) and sugar-beet pulp (SBP), mixed at two constant proportions, (0·75: 0·25) AH diets and (0·25: 0·75) SBP diets. Both diets included either barley or maize grain at two fibre: grain ratios (F/G, 80: 20 and 45: 55). Diets were given ad libitum. Growth rate, dry matter intake and digestibility were not modified by the grain source, although high F/G diets resulted in a lower growth rate (19·8 v. 26·4 g/day; P < 0·001). Between fibre sources, dry-matter intake and growth were higher in AH than in SBP diets (122·5 and 25·6 v. 101·6 and 20·4 g/day, respectively, P < 0·001 and P < 0·01). Rabbits given high F/G ratio and AH diets excreted more caecotrophes than those given low F/G ratio and SBP diets (19·5 and 20·9 v. 16·3 and 14·85 g/day, respectively). Microbial-N recycling through the caecotrophy process was higher when considering data from PD excretion (1·33 g/d) than when estimated by preventing caecotrophy (0·72 g/day).
We present an extensive physical characterization of La2/3Ca1/3MnO3 (LCMO) epitaxial films grown on SrTiO3 (STO), LaAlO3 (LAO) and NdGaO3 (NGO) substrates. The main difference among these substrates is that they have a different mismatch (∼ 1.2%, -1.8% and - 0.1%, respectively) with the manganite. The films can be coherently grown up to 180 nm for STO and NGO but partial relaxation is observed for LAO. The magnetotransport data indicate that very thin films (<27nm) display non-conventional magnetoresistive properties: a substantial magnetoresistance develops which can be progressively appreciated for STO and LAO films. 55Mn-Nuclear Magnetic Resonance experiments on all these films reveal the presence of non-homogeneous electronic states. These experiments in fact provide clear evidence of the presence of two distinguishable ferromagnetic Mn states and a non-ferromagnetic phase. The possible role of strain-induced charge localization is discussed. It turns out that electronic phase separation occurs in all films irrespectively of the particular substrate used; thus we conclude that strain is not the unique driving force for charge localization.
Rabbits are able to recycle most of the microbial protein produced in the caecum by means of caecotrophagy. Caecotrophagy consists in a selective retention in the caecum of fluid and small particles (as vehicles of microorganism) that results in two type of faeces. Excretion of large and indigestible particles constitute the hard faeces whereas excretion of fermented material generate caecotrophes or soft faeces, that are reingested for the animal. It is true that bacterial-N represents the major part of caecotrofes-N. However, a fraction of indigestible dietary N and some addition of endogenous N can modify the final nutritive value of the caecotrophes (Hörnicke & Bjornahg, 1980). The aim of this study was to compare the Nitrogenous composition of bacteria extracted from the caecum against caecotrophes.
Three experiments were carried out to establish a response model between intake and urinary excretion of purine compounds. In Expt 1 the relationship between the intake of purine bases (PB) and the excretion of total purine derivatives (PD) was determined in seven growing rabbits with a mean initial live weight (LW) of 2·03 (SE 0·185) kg, aged 70 d, each fitted with a wooden neck collar to prevent caecotrophagy. They were fed on five experimental diets formulated with different levels of nucleic acids (0·00, 3·75, 7·50, 11·25, 15·00 g yeast-RNA/kg diet). The relationship between intake of purine (x, μmol/kg W0·75) and total urinary PD excretion (y, μmol/kg W0·75), y = 0·56 + 0·67x (r2 0·86; RSD 0·338), indicated that about 70% of duodenal PB were recovered as urinary PD and that the endogenous contribution was constant and independent of dietary PB supply. Endogenous excretion of PD (allantoin and uric acid) was measured in a second experiment using six rabbits fed on a purine-free diet and fitted with neck collars to avoid caecotrophagy. Basal daily urinary excretion values for allantoin and uric acid were 532 (SE 33·9) and 55 (SE 7·3) μmol/kg W0·75 respectively; xanthine and hypoxanthine were not found in urine samples and therefore the sum of allantoin and uric acid should comprise the total excretion of PD (588 (SE 40·1) μmol/kg W0·75). The xanthine oxidase (EC 1·2.3·2) activity in plasma, liver, duodenum, jejunum and kidney was measured in a third experiment. The activities of xanthine oxidase in duodenal and jejunal mucosa, liver and kidney were: 0·61 (SE 0·095), 0·37 (SE 0·045), 0·035 (SE 0·001) and 0 units/g fresh tissue respectively and in plasma 2·96 (SE 0·094) units/1. The results show that urinary excretion of PD may be a useful tool to estimate duodenal PB input and microbial protein intake once the relationship between PB and N has been established in caecal micro-organisms.
The present study examined the endogenous urinary excretion of purine derivatives (PD; allantoin, uric acid and xanthine plus hypoxanthine) in fed animals. Four Rasa Aragonesa ewes fitted with simple cannulas in the rumen and proximal duodenum were used. Animals were given a lucerne (Medicago sativa) hay diet, as sole feed (A) or supplemented, respectively, with 220 (B), 400 (C), and 550 (D) g rolled barley grain/d following a 4 × 4 random factorial design. Duodenal flow of purine bases (PB) was determined by the dual-phase marker system. 15N was infused continuously into the rumen to label exogenous or microbial PB. Duodenal PB flow and urinary excretion of PD increased with digestible organic matter intake showing a constant recovery of duodenal PB. The isotope dilution of PD in urine samples confirmed the presence of an endogenous fraction, originating from tissues, that increased from 115.2 (SE 5.84) μmol/kg W0.75 for the basal diet to 304.2 (SE 7.6) μmol/kg W0.75 at the highest level of duodenal PB.
Values of ammonia concentration in rumen liquid have been used as an index of nitrogen requirements of rumen microflora even though ammonia requirements seem to depend on the type of diet. Cellulollitic flora mainly use ammonia as N source, while bacteria that ferment non-structural carbohydrates use either ammonia or protein nitrogen. The aim of this experiment was to establish the minimum concentration of ammonia to optimise microbial synthesis in the rumen of steers fed concentrate-based diets.
For a sample of bright nearby early-type galaxies we have obtained surface photometry in bands ranging from U to K. Since the galaxies have inclinations larger than 50° it is easy to separate bulges and disks. By measuring the colours in special regions, we minimize the effects of extinction, and by looking at B – K colour gradients we can show that for these type of spirals the colours mainly give information about stellar populations, and not extinction. We find that the differences between bulges and disks in all colours is very small, and using simple population models we can show that on the average the age difference between the bulge and the disk at 2 scale length is smaller than 30%, and much smaller if part of the difference is caused by a gradient in metallicity.