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991.
Between the 1910s and the 1940s, American naturalists carried out a number of ornithological expeditions in Colombia. With the help of Colombian naturalists, thousands of skins were brought to natural history museums in the United States. By 1948 these birds had become an important treasure: American ornithologists declared Colombia the nation with the most bird species. This story sheds new light on the role science played in the expansion of U.S. political, economic, and cultural influence in Latin America in the early twentieth century, as well as on the relation between nationalist movements in Latin America and the study of the natural world. Recognizing a complex but fruitful interaction between nationalist policies and imperial practices proves important for understanding the success of the naturalists' enterprise in Colombia.  相似文献   
992.
Based on three ethnographic vignettes describing the engagements of a small start-up company with prospective competitors, partners and customers, this paper shows how commercial considerations are folded into the ways visual images become 'seeable'. When company members mount demonstrations of prototype mammography software, they seek to generate interest but also to protect their intellectual property. Pivotal to these efforts to manage revelation and concealment is the visual interface, which is variously performed as obstacle and ally in the development of a profitable product. Using the concept of 'face value', the paper seeks to develop further insight into contemporary dynamics of seeing and showing by tracing the way techno-visual presentations and commercial considerations become entangled in practice. It also draws attention to the salience and significance of enactments of surface and depth in image-based practices.  相似文献   
993.
In this study, differences in lipid levels amongst diabetics with and without complications were assessed to determine lipid disorders that are associated with diabetic complications other than cardiovascular diseases. A Cross sectional study design was employed. The study included 288 diabetics and 108 non diabetics with different types of complications such as hypertension, nephropathy, neuropathy, and retinopathy. The mean serum total cholesterol was higher in patients with complications compared to those without complications and the non-diabetic controls. The normotensive diabetic patients had the lowest total cholesterol among the diabetic patients’ groups (4.65 ± 0.17 mmol/l) compared to the diabetics with hypertension (6.051 ± 0.20 mmol/l), retinopathy (6.26 ± 0.29 mmol/l), neuropathy (5.80 ± 0.17 mmol/l) and nephropathy patients 5.74 ± 0.26 mmol/l (P < 0.05). The prevalence of dyslipidaemia among diabetic subjects was between 19.2 and 84.0%. The study shows that, in addition to macrovascular complications, dyslipidaemia is common in type 2 diabetes mellitus patients with microvascular complications.  相似文献   
994.
Suspicion of inflammatory bowel disease should be raised in any patient with chronic or recurrent abdominal pain and diarrhoea. However, symptoms of inflammatory bowel disease (IBD) overlap with functional gastrointestinal disorders and those patients may not need endoscopy. Currently, colonoscopy with multiple biopsies is considered the gold standard to establish the diagnosis of IBD. Unfortunately, patient selection for endoscopy based on symptoms is not reliable. The use of guidelines of appropriateness for endoscopy yields significantly more significant findings but the selection criteria suffer from low specificity. Calprotectin is a calcium binding protein of neutrophil granulocytes that correlates well with neutrophil infiltration of the intestinal mucosa when measured in faeces. In the last decade, a large body of evidence on the diagnostic value of faecal calprotectin has accumulated and measurement of calprotectin in faeces has been suggested as a surrogate marker of intestinal inflammation. Testing of faecal calprotectin has been highly useful to distinguish organic from functional intestinal disorders in patients with abdominal complaints. Additionally, faecal calprotectin has reliably identified colonic inflammation in patients with suspected IBD. The use of this inexpensive and widely available test in the evaluation and risk stratification in patients with abdominal complaints is likely to increase in the future.  相似文献   
995.
纳米材料与农作物之间的相互作用:食品安全与启示   总被引:2,自引:0,他引:2  
研究目的:通过综述作物对纳米材料的吸收途径和积累,以及纳米材料对农作物生长和营养的影响,为纳米污染在农业中的风险提供理论分析和启示。 创新要点:归纳了纳米材料被作物吸收的路径和对作物生理、遗传、营养各水平上产生的胁迫。重要结论:当前纳米与作物的研究应集中在食品安全相关的问题上,考虑农业实际情况和环境因素,分析纳米材料通过食物链富集和传递的可能性,探讨纳米材料与其他土壤有机污染物可能产生的复合污染。  相似文献   
996.
裕固族宗教研究虽然取得了一定的成就,但是近年来进展较为缓慢,主要原因在于对新的研究资料的挖掘力度不够。本文是在长期田野调查的基础上撰写的,通过叙述与裕固族有关的三个喇嘛的轶事,从而为裕固族宗教研究的深化和拓展提供新的资料和视角。  相似文献   
997.
998.
Most previous research on golf swing mechanics has focused on the driver club. The aim of this study was to identify the kinematic factors that contribute to greater hitting distance when using the 5 iron club. Three-dimensional marker coordinate data were collected (250 Hz) to calculate joint kinematics at eight key swing events, while a swing analyser measured club swing and ball launch characteristics. Thirty male participants were assigned to one of two groups, based on their ball launch speed (high: 52.9 ± 2.1 m · s(-1); low: 39.9 ± 5.2 m · s(-1)). Statistical analyses were used to identify variables that differed significantly between the two groups. Results showed significant differences were evident between the two groups for club face impact point and a number of joint angles and angular velocities, with greater shoulder flexion and less left shoulder internal rotation in the backswing, greater extension angular velocity in both shoulders at early downswing, greater left shoulder adduction angular velocity at ball contact, greater hip joint movement and X Factor angle during the downswing, and greater left elbow extension early in the downswing appearing to contribute to greater hitting distance with the 5 iron club.  相似文献   
999.
The aim of the study was to determine whether there is empirical evidence for advantages in performance of soccer teams because of their relative age. The practice of selecting youth players according to their momentary performance leads to relative age effects, which in turn lead to inefficient talent selection. We used the median of the birth dates as a measure of the effect size of the relative age effect and the Kolmogorov-Smirnov test to assess its significance. For the 2008-2009 season, birth dates in the three German U-17 first leagues for soccer were examined (911 players). More than half of the 41 teams differed significantly from the distribution of the corresponding German cohort. There was a significant correlation between the relative age effect and success defined by teams' final rankings (Spearman's ρ = 0.328, P = 0.036). Regression analyses revealed that with a median of birth dates one month earlier the team is expected to finish 1.035 ranks better. Accordingly, selecting early born athletes is an important aspect of success in youth soccer. However, teams with no relative age effect are able to compete in the league, having the benefit to promote players with a better perspective for long and successful careers at an adult age.  相似文献   
1000.
The main aim of this study was to assess the physiological responses of male basketball players during usual basketball ball-drills. Fourteen male basketball players (age 18.9 ± 2.3 years) performed the following full-court (28 × 15 m) basketball ball-drills (3 × 4-min with 3-min passive rest): five-a-side (5v5), three-a-side (3v3) and two-a-side (2v2). A main effect (P < 0.0001) for ball-drills modes was evident for all variables (5v5 < 3v3 < 2v2). Mean [Vdot]O(2) during the 5v5, 3v3 and 2v2 were 39.0 ± 7.2, 42.0 ± 7.5 and 45.0 ± 6.5 ml · kg(-1) · min(-1) (69 ± 11, 74 ± 12 and 79 ± 11% of [Vdot]O(2peak)) respectively (5v5 = 3v3 < 2v2, P < 0.001). Mean blood-lactate concentrations for 5v5, 3v3 and 2v2 were 4.2 ± 1.8, 6.2 ± 2.3 and 7.8 ± 1.2 mmol (l(-1) respectively (5v5 < 3v3 < 2v2, P < 0.01). During the 5v5, 3v3 and 2v2 mean heart-rate (HR) was 84.0 ± 9.2, 88.0 ± 8.4 and 92.0 ± 5.6% of the individual peak respectively (5v5 < 3v3 < 2v2; P < 0.001). No significant differences were found between the regression-line slope (P = 0.86) and intercept (P = 0.45) of the HR-[Vdot]O(2) relationships of the multistage maximal fitness test (r(2) from 0.80 to 0.96, P < 0.001) and ball-drills (r(2) from 0.70 to 0.95, P < 0.001) conditions. Reducing the number of players over the same playing court resulted in increments in physiological demands. The 2v2 condition provided responses in the range of those reported to improve aerobic and anaerobic fitness. The aerobic demands of ball-drills can be accurately assessed using heart-rate monitoring in basketball.  相似文献   
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