899 resultados para Vespucci, Amerigo (1454-1512)
Resumo:
The anatomy of the human brain is organized as a complex arrangement of interrelated structures in three dimensional space. To facilitate the understanding of both structure and function, we have created a volume rendered brain atlas (VRBA) with an intuitive interface that allows real-time stereoscopic rendering of brain anatomy. The VRBA incorporates 2-dimensional and 3-dimensional texture mapping to display segmented brain anatomy co-registered with a T1 MRI. The interface allows the user to remove and add any of the 62 brain structures, as well as control the display of the MRI dataset. The atlas also contains brief verbal and written descriptions of the different anatomical regions to correlate structure with function. A variety of stereoscopic projection methods are supported by the VRBA and provide an abstract, yet simple, way of visualizing brain anatomy and 3-dimensional relationships between different nuclei.
Resumo:
The purpose of this study was to investigate variations in hepatic regulation of metabolism during the dry period, after parturition, and in early lactation in dairy cows. For this evaluation, cows were divided into 2 groups based on the plasma concentration of beta-hydroxybutyric acid (BHBA) in wk 4 postpartum (PP; group HB, BHBA >0.75 mmol/L; group LB, BHBA <0.75 mmol/L, respectively). Liver biopsies were obtained from 28 cows at drying off (mean 59 +/- 8 d antepartum), on d 1, and in wk 4 and 14 PP. Blood samples were collected every 2 wk during this entire period. Liver samples were analyzed for mRNA abundance of genes related to carbohydrate metabolism (pyruvate carboxylase, PC; phosphoenolpyruvate carboxykinase, PEPCK; citrate synthase, CS), fatty acid biosynthesis (ATP citrate lyase, ACLY) and oxidation (acyl-CoA synthetase long-chain, ACSL; carnitine palmitoyltransferase 1A, CPT 1A; carnitine palmitoyltransferase 2, CPT 2; acyl-coenzyme A dehydrogenase very long chain, ACADVL), cholesterol biosynthesis (3-hydroxy-3-methylglutaryl-coenzyme A synthase 1, HMGCS1), ketogenesis (3-hydroxy-3-methylglutaryl-coenzyme A synthase 2, HMGCS2), and of genes encoding the transcription factors peroxisome proliferator-activated receptor alpha (PPARalpha), peroxisome proliferator-activated receptor gamma (PPARgamma), and sterol regulatory element binding factor 1 (SREBF1). Blood plasma was assayed for concentrations of glucose, BHBA, nonesterified fatty acids, cholesterol, triglycerides, insulin, insulin-like growth factor-I, and thyroid hormones. In both groups, plasma parameters followed a pattern usually observed in dairy cows. However, changes were moderate and the energy balance in cows turned positive in wk 7 PP for both groups. Additionally, the energy balance and milk yield were similar for both groups after parturition onwards. Significant group effects were found at drying off, when plasma concentrations of triglycerides were higher in LB than in HB, and in wk 4 PP, when plasma concentrations of glucose and IGF-I were lower in HB than in LB. Similarly, moderate changes in mRNA expression of hepatic genes between the different time points were observed, although HB cows showed more adaptive performance than LB cows based on changes in mRNA expression of PEPCKc, PEPCKm, CS, CPT 1A, CPT 2, and PPARalpha. Part of the variation measured in this study was explained by parity. Significant Spearman rank correlation coefficients between the variables were not similar at each time point and were not similar between the groups at each time point, suggesting that metabolic regulation differs between cows. In conclusion, metabolic regulation in dairy cows is a dynamic system, and differs obviously between cows at different metabolic stages related to parturition.
Resumo:
Hepatitis B virus (HBV) infection is a major cause of morbidity and mortality in human immunodeficiency virus (HIV)-infected patients worldwide. It is unclear whether HIV-related outcomes are affected by HBV coinfection. We compared virological suppression and immunological recovery during antiretroviral therapy (ART) of patients of different HBV serological status in the Swiss HIV Cohort Study. CD4 cell recovery during ART was significantly impaired in hepatitis B surface antigen-positive patients and in those with anti-hepatitis B core antigen alone compared with HBV-uninfected patients, despite similar virological efficacy of ART. CD4 increase in patients with resolved HBV infection was similar to that in HBV-uninfected individuals.
Resumo:
Formation of the so far elusive chrysene excimer in solution is achieved by using DNA as a supramolecular scaffold. Oligonucleotides possessing one or two chrysene building blocks have been synthesized. Chrysene excimer fluorescence has been unambiguously observed in DNA double strands, as well as in single strands containing two neighbouring chrysenes.
Resumo:
CONTEXT Dementia care giving can lead to increased stress, physical and psychosocial morbidity, and mortality. Anecdotal evidence suggests that hospice care provided to people with dementia and their caregivers may buffer caregivers from some of the adverse outcomes associated with family caregiving in Alzheimer's Disease (AD). OBJECTIVES This pilot study examined psychological and physical outcomes among 32 spousal caregivers of patients with AD. It was hypothesized that caregivers who utilized hospice services would demonstrate better outcomes after the death of their spouse than caregivers who did not utilize hospice. METHODS The charts of all spousal caregivers enrolled in a larger longitudinal study from 2001 to 2006 (N=120) were reviewed, and participants whose spouse had died were identified. Of these, those who received hospice care (n=10) were compared to those who did not (n=22) for various physiological and psychological measures of stress, both before and after the death of the care recipient. An Analysis of Covariance (ANCOVA), with postdeath scores as the dependent variable and pre-death scores as covariates, was used for all variables. RESULTS Significant group differences were found in postdeath depressive symptoms (HAM-D; F(1,29)=6.10, p<0.05) and anxiety symptoms (HAM-A; F(1,29)=5.71, p<0.05). Most psychological outcome variables demonstrated moderate effect sizes with a Cohen's d of>0.5 between groups. CONCLUSIONS These data suggest that hospice enrollment may ameliorate the detrimental psychological effects in caregivers who have lost a spouse with Alzheimer's Disease. Based on these pilot data, further prospective investigation is warranted.
Resumo:
Lors des votations populaires en Suisse, le Conseil fédéral fait connaître la position gouvernementale à l’aide de brochures envoyées à tous les citoyens. Celles-ci mettent en jeu une corrélation étroite entre argumentation et interaction, tant sur le plan interdiscursif qu’interlocutif. L’objectif de cet article est de montrer, à partir de brochures représentatives, comment une telle corrélation varie fortement selon les stratégies adoptées par le Conseil fédéral. Ainsi, dans les brochures proposant un projet de référendum, on remarque une interaction limitée, en raison de leur argumentation rationnelle et de leur tendance à se fermer sur le point de vue du Conseil fédéral. Par contre, dans les brochures soutenant ou rejetant des initiatives populaires, on observe une montée au premier plan des procédures interactives. Celles-ci peuvent être convergentes ou divergentes, en liaison avec différentes stratégies argumentatives qui vont de la surenchère à la polémique. Au total, ces brochures gouvernementales nous confirment que l’analyse du discours politique gagne à être repensée à l’aide des modèles dits « dialogaux » (Plantin 2005) de l’argumentation.
Resumo:
Mountain vegetation is strongly affected by temperature and is expected to shift upwards with climate change. Dynamic vegetation models are often used to assess the impact of climate on vegetation and model output can be compared with paleobotanical data as a reality check. Recent paleoecological studies have revealed regional variation in the upward shift of timberlines in the Northern and Central European Alps in response to rapid warming at the Younger Dryas/Preboreal transition ca. 11700years ago, probably caused by a climatic gradient across the Alps. This contrasts with previous studies that successfully simulated the early Holocene afforestation in the (warmer) Central Alps with a chironomid-inferred temperature reconstruction from the (colder) Northern Alps. We use LandClim, a dynamic landscape vegetation model to simulate mountain forests under different temperature, soil and precipitation scenarios around Iffigsee (2065m a.s.l.) a lake in the Northwestern Swiss Alps, and compare the model output with the paleobotanical records. The model clearly overestimates the upward shift of timberline in a climate scenario that applies chironomid-inferred July-temperature anomalies to all months. However, forest establishment at 9800 cal. BP at Iffigsee is successfully simulated with lower moisture availability and monthly temperatures corrected for stronger seasonality during the early Holocene. The model-data comparison reveals a contraction in the realized niche of Abies alba due to the prominent role of anthropogenic disturbance after ca. 5000 cal. BP, which has important implications for species distribution models (SDMs) that rely on equilibrium with climate and niche stability. Under future climate projections, LandClim indicates a rapid upward shift of mountain vegetation belts by ca. 500m and treeline positions of ca. 2500m a.s.l. by the end of this century. Resulting biodiversity losses in the alpine vegetation belt might be mitigated with low-impact pastoralism to preserve species-rich alpine meadows.
Resumo:
BACKGROUND The extent of hypoperfusion is an important prognostic factor in acute ischemic stroke. Previous studies have postulated that the extent of prominent cortical veins (PCV) on susceptibility-weighted imaging (SWI) reflects the extent of hypoperfusion. Our aim was to investigate, whether there is an association between PCV and the grade of leptomeningeal arterial collateralization in acute ischemic stroke. In addition, we analyzed the correlation between SWI and perfusion-MRI findings. METHODS 33 patients with acute ischemic stroke due to a thromboembolic M1-segment occlusion underwent MRI followed by digital subtraction angiography (DSA) and were subdivided into two groups with very good to good and moderate to no leptomeningeal collaterals according to the DSA. The extent of PCV on SWI, diffusion restriction (DR) on diffusion-weighted imaging (DWI) and prolonged mean transit time (MTT) on perfusion-imaging were graded according to the Alberta Stroke Program Early CT Score (ASPECTS). The National Institutes of Health Stroke Scale (NIHSS) scores at admission and the time between symptom onset and MRI were documented. RESULTS 20 patients showed very good to good and 13 patients poor to no collateralization. PCV-ASPECTS was significantly higher for cases with good leptomeningeal collaterals versus those with poor leptomeningeal collaterals (mean 4.1 versus 2.69; p=0.039). MTT-ASPECTS was significantly lower than PCV-ASPECTS in all 33 patients (mean 1.0 versus 3.5; p<0.00). CONCLUSIONS In our small study the grade of leptomeningeal collateralization correlates with the extent of PCV in SWI in acute ischemic stroke, due to the deoxyhemoglobin to oxyhemoglobin ratio. Consequently, extensive PCV correlate with poor leptomeningeal collateralization while less pronounced PCV correlate with good leptomeningeal collateralization. Further SWI is a very helpful tool in detecting tissue at risk but cannot replace PWI since MTT detects significantly more ill-perfused areas than SWI, especially in good collateralized subjects.
Resumo:
ABSTRACT Hope is increasingly recognized as an important psychological resource for career development, yet the empirical research on its functioning in this domain is sparse. This paper describes an investigation of how dispositional hope is related to career decidedness, career planning, and career self-efficacy beliefs and whether these more proximal career attitudes mediate the effects of hope on proactive career behaviors, life satisfaction, and job satisfaction. This investigation was conducted using two independent samples of university students (N = 1,334) and working professionals (N = 233). The results showed that in both samples, hope was significantly related but empirically distinct from career variables. In both samples, hope had a direct effect on proactive career behaviors, partially mediated by more career planning. Hope had significant direct and indirect effects on life satisfaction among students, mediated by the three career development attitudes. Although hope was significantly correlated with job satisfaction among employees, no direct effect of hope was found in the mediation model, but an indirect effect through career decidedness was found. The results suggest that hope is an important resource for proactive career development at different career stages and that the positive relation of hope to life and job satisfaction can partially be attributed to the positive relation between hope and favorable career development attitudes.
Resumo:
Johann Reuchlin
Resumo:
This paper presents a unique 517-yr long documentary data-based reconstruction of spring-summer (MAMJJ) temperatures for northern Switzerland and southwestern Germany from 1454 to 1970. It is composed of 25 partial series of winter grain (secale cereale) harvest starting dates (WGHD) that are partly based on harvest related bookkeeping of institutions (hospitals, municipalities), partly on (early) phenological observations. The resulting main Basel WGHD series was homogenised with regard to dating style, data type and altitude. The calibration and verification approach was applied using the homogenous HISTALP temperature series from 1774–1824 for calibration (r = 0.78) and from 1920–1970 for verification (r = 0.75). The latter result even suffers from the weak data base available for 1870– 1950. Temperature reconstructions based on WGHD are more influenced by spring temperatures than those based on grape harvest dates (GHD), because rye in contrast to vines already begins to grow as soon as sunlight brings the plant to above freezing. The earliest and latest harvest dates were checked for consistency with narrative documentary weather reports. Comparisons with other European documentarybased GHD and WGHD temperature reconstructions generally reveal significant correlations decreasing with the distance from Switzerland. The new Basel WGHD series shows better skills in representing highly climate change sensitive variations of Swiss Alpine glaciers than available GHD series.