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Selected AbstractsPrediabetes and the big baby,DIABETIC MEDICINE, Issue 1 2008D. R. Hadden Abstract The concept of prediabetes has come to the fore again with the worldwide epidemic of Type 2 diabetes. The careful observations of W. P. U. Jackson and his colleagues in Cape Town, South Africa 50 years ago still deserve attention. Maternal hyperglycaemia cannot be the only cause of fetal macrosomia, and the pathophysiological reason for the unexplained stillbirth in late diabetic pregnancy still eludes us. The biochemical concepts of ,facilitated anabolism' and ,accelerated starvation' were developed by Freinkel as explanations of the protective mechanisms for the baby during the stresses of pregnancy. Some of these nutritional stresses may also occur in the particular form of early childhood malnutrition known in Africa as kwashiorkor, where subcutaneous fat deposition, carbohydrate intolerance, islet hyperplasia and sudden death may follow a period of excess carbohydrate and deficient protein intake. Different feeding practices in different parts of the world make comparisons uncertain, but there is evidence for insulin resistance in both the macrosomic fetus of the hyperglycaemic mother and in the child with established kwashiorkor. These adaptive changes in early development may play both a physiological and a pathological role. Worldwide studies of hyperglycaemia in pregnancy are gradually establishing acceptable diagnostic criteria, appropriate screening procedures and an evidence base for treatment. Nevertheless the challenge of prediabetes and the big baby is still with us,in Jackson's words,,diabetes mellitus is a fascinating condition,the more we know about it the less we understand it'. [source] Ultrastructure of spermatozoa of scolecophidian snakes (Lepidosauria, Squamata)ACTA ZOOLOGICA, Issue 3 2007L. Tavares-Bastos Abstract We provide a detailed description of the sperm ultrastructure of three species of scolecophidian snakes, Leptotyphlops koppesi (Leptotyphlopidae), Typhlops reticulatus (Typhlopidae) and Liotyphlops beui (Anomalepididae), and make comparisons with the spermatozoa of Ramphotyphlops waitii (Typhlopidae) (Harding et al. 1995). All the species studied bear synapomorphies of Squamata and Serpentes. Among scolecophidian snakes, we identified eight polymorphic characters. Previous analyses of molecular and somatic morphological data provide equivocal solutions to the relationships among Anomalepididae, Leptotyphlopidae and Typhlopidae. A close relationship between Anomalepididae and Typhlopidae is corroborated by two characters of sperm ultrastructure, presence of an electron-dense structure inside the proximal centriole and rounded mitochondria in transverse sections of T. reticulatus, Li. beui and R. waitii, whereas the absence of the ridge on the acrosome surface of Le. koppesi and T. reticulatus support a closer relationship between Typhlopidae and Leptotyphlopidae. The differences observed in sperm ultrastructure within Typhlopidae suggest the existence of snake intrafamilial polymorphism. The sperm characters of blindsnakes contain significant phylogenetic information and may provide important data for snake phylogenetic reconstructions. [source] The Contribution of Chemoreflex Drives to Resting Breathing in ManEXPERIMENTAL PHYSIOLOGY, Issue 1 2001Safraaz Mahamed The contribution of automatic drives to breathing at rest, relative to behavioural drives such as ,wakefulness', has been a subject of debate. We measured the combined central and peripheral chemoreflex contribution to resting ventilation using a modified rebreathing method that included a prior hyperventilation and addition of oxygen to maintain isoxia at a PET,O2 (end-tidal partial pressure of oxygen) of 100 mmHg. During rebreathing, ventilation was unrelated to PET,CO2 (end-tidal partial pressure of carbon dioxide) in the hypocapnic range, but after a threshold PET,CO2 was exceeded, ventilation increased linearly with PET,CO2. We considered the sub-threshold ventilation to be an estimate of the behavioural drives to breathe (mean ± S.E.M. = 3.1 ± 0.5 l min,1), and compared it to ventilation at rest (mean ± S.E.M. = 9.1 ± 0.7 l min,1). The difference was significant (Student's paired t test, P < 0.001). We also considered the threshold PCO2 observed during rebreathing to be an estimate of the chemoreflex threshold at rest (mean ± S.E.M. = 42.0 ± 0.5 mmHg). However, PET,CO2 during rebreathing estimates mixed venous or tissue PCO2, whereas the resting PET,CO2 during resting breathing estimates Pa,CO2 (arterial partial pressure of carbon dioxide). The chemoreflex threshold measured during rebreathing was therefore reduced by the difference in PET,CO2 at rest and at the start of rebreathing (the plateau estimates the mixed venous PCO2 at rest) in order to make comparisons. The corrected chemoreflex thresholds (mean ± S.E.M. = 26.0 ± 0.9 mmHg) were significantly less (paired Student's t test, P < 0.001) than the resting PET,CO2 values (mean ± S.E.M. = 34.3 ± 0.5 mmHg). We conclude that both the behavioural and chemoreflex drives contribute to resting ventilation. [source] Generalization of belief and plausibility functions to fuzzy sets based on the sugeno integralINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 11 2007Chao-Ming Hwang Uncertainty has been treated in science for several decades. It always exists in real systems. Probability has been traditionally used in modeling uncertainty. Belief and plausibility functions based on the Dempster,Shafer theory (DST) become another method of measuring uncertainty, as they have been widely studied and applied in diverse areas. Conversely, a fuzzy set has been successfully used as the idea of partial memberships of multiple classes for the presentation of unsharp boundaries. It is well used as the representation of human knowledge in complex systems. Nowadays, there exist several generalizations of belief and plausibility functions to fuzzy sets in the literature. In this article, we propose a new generalization of belief and plausibility functions to fuzzy sets based on the Sugeno integral. We then make comparisons of the proposed generalization with some existing methods. The results show the effectiveness of the proposed generalization, especially for being able to catch more information about the change of fuzzy focal elements. © 2007 Wiley Periodicals, Inc. Int J Int Syst 22: 1215,1228, 2007. [source] An Examination of Cross-Racial Comparability of Mother-Child Interaction Among African American and Anglo American FamiliesJOURNAL OF MARRIAGE AND FAMILY, Issue 3 2001Leanne Whiteside-Mansell This study examined the cross-racial comparability of maternal quality of assistance and supportive presence coded from a video protocol using data from the Infant Health and Development Program for low-birth-weight, premature 30-month-olds and their mothers. Evidence of equivalence of measures is necessary before comparisons can be made across groups. Multiple-group mean and covariance structures analysis was used to demonstrate the invariance of the measures and make comparisons for Anglo American and African American treatment and comparison groups of dyads. Comparisons across groups indicated similar variances and correlation between child and maternal behavior. Differences were found between the mean scores, with Anglo American treatment families scoring the highest. [source] A prospective analysis of incidence and severity of quadriceps inhibition in a consecutive sample of 100 patients with complete acute anterior cruciate ligament ruptureJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2004Terese L. Chmielewski Background: Weakness of the quadriceps femoris muscle after anterior cruciate ligament injury and reconstruction has been attributed to incomplete voluntary activation of the muscle. The literature is conflicting on the incidence of incomplete voluntary quadriceps activation after anterior cruciate ligament injury because of differences in testing methods and population biases. The purpose of this study was to systematically examine the incidence and severity of quadriceps voluntary activation failure in both lower extremities after acute anterior cruciate ligament injury. We hypothesized that the incidence of quadriceps inhibition would be higher in the anterior cruciate ligament injured limbs than the uninvolved limbs, that the incidence of inhibition in the anterior cruciate ligament deficient limbs would be larger than in our historical sample of healthy young individuals tested in the same manner and that there would be no difference in inhibition by gender. Study design: Prospective, descriptive. Methods: One hundred consecutive patients with acute anterior cruciate ligament rupture (39 women and 61 men) were tested when range of motion was restored and effusion resolved, an average of 6 weeks after injury. A burst superimposition technique was used to assess quadriceps muscle activation and strength in all patients. Dependent t -tests were used to compare side-to-side differences in quadriceps strength. Independent t -tests were used to compare incidence of activation failure by gender and make comparisons to historical data on young, active individuals. Results: The average involved side quadriceps activation was 0.92, and ranged from 0.60 to 1.00. The incidence of incomplete activation in the involved side quadriceps was 33 per cent and uninvolved side quadriceps was 31 per cent after acute anterior cruciate ligament rupture. The incidence of incomplete activation bilaterally was 21 per cent. There was no difference in incidence of quadriceps inhibition by gender. Conclusion: The incidence of voluntary quadriceps inhibition on the involved side was three times that of uninjured, active young subjects, but the magnitude was not large. The incidence of quadriceps inhibition on the uninjured side was similar to the injured side. Clinical relevance: Both the incidence and magnitude of quadriceps inhibition after ACL rupture are lower than have previously been reported. The conventional wisdom, therefore, that quadriceps inhibition is a significant problem in this population is challenged by the results of this study. Differences between this study and others include sufficient practice to ensure a maximal effort contraction and rigorous inclusion criteria. The findings have implications for strength testing as well as rehabilitation. The quadriceps index, an assessment of the injured side quadriceps strength deficit may be affected by the presence of voluntary activation failure in the uninvolved side. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Consistency and crossbreeding in French speaking regional science: An epistemological investigation,PAPERS IN REGIONAL SCIENCE, Issue 4 2003Claude Lacour Regional science; epistemology; semantic fields; crossbreeding phenomenon Abstract. This article assesses the output of French-speaking regional scientists based on published works in Revue d'Economie Régionale et Urbaine (1978,1999). We explore quantitative and qualitative aspects of regional science and make comparisons with Anglo-Saxon research. We focus on the topics, style and concepts studied and used over time. Our analysis scrutinises changes in the current patterns of thought used in French speaking regional science. We also demonstrate narrow and broad semantic fields according to regional science issues and explore the phenomenon of crossbreeding between fields of studies. [source] Upper extremity pain and computer use among engineering graduate students: A replication studyAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 2 2009Cammie Chaumont Menéndez PhD Abstract Background Recent literature identified upper extremity musculoskeletal symptoms at a prevalence of >40% in college populations. The study objectives were to determine weekly computer use and the prevalence of upper extremity musculoskeletal symptoms in a graduate student population, and make comparisons with previous graduate and undergraduate cohorts. Methods One hundred sixty-six graduate students completed a survey on computing and musculoskeletal health. Associations between individual factors and symptom status, functional limitations, academic impact, medication use, and health services utilization were determined. Logistic regression analyses evaluated the association between symptom status and computing. Cross-study comparisons were made. Results More symptomatic participants experienced functional limitations than asymptomatic participants (74% vs. 32%, P,<,0.001) and reported medication use for computing pain (34% vs. 10%, P,<,0.01). More participants who experienced symptoms within an hour of computing used health services compared to those who experienced symptoms after an hour of computer use (60% vs. 12%, P,<,0.01). Years of computer use (OR,=,1.59, 95% CI 1.05,2.40) and number of years in school where weekly computer use was more than 10 hr (OR,=,1.56, 95% CI 1.04,2.35) were associated with pain within an hour of computing. Cross-study comparisons found college populations more similar than different. Conclusion The overall findings reinforced previous literature documenting the prevalence of upper extremity musculoskeletal symptoms in college populations, suggesting an important population for participating in public health interventions designed to support healthy computing practices and identify risk factors important to evaluate in future cohort studies. Am. J. Ind. Med. 52:113,123, 2009. © 2008 Wiley-Liss, Inc. [source] Fig-eating by vertebrate frugivores: a global reviewBIOLOGICAL REVIEWS, Issue 4 2001MIKE SHANAHAN ABSTRACT The consumption of figs (the fruit of Ficus spp.; Moraceae) by vertebrates is reviewed using data from the literature, unpublished accounts and new field data from Borneo and Hong Kong. Records of frugivory from over 75 countries are presented for 260 Ficus species (approximately 30% of described species). Explanations are presented for geographical and taxonomic gaps in the otherwise extensive literature. In addition to a small number of reptiles and fishes, 1274 bird and mammal species in 523 genera and 92 families are known to eat figs. In terms of the number of species and genera of fig-eaters and the number of fig species eaten we identify the avian families interacting most with Ficus to be Columbidae, Psittacidae, Pycnonotidae, Bucerotidae, Sturnidae and Lybiidae. Among mammals, the major fig-eating families are Pteropodidae, Cercopithecidae, Sciuridae, Phyllostomidae and Cebidae. We assess the role these and other frugivores play in Ficus seed dispersal and identify fig-specialists. In most, but not all, cases fig specialists provide effective seed dispersal services to the Ficus species on which they feed. The diversity of fig-eaters is explained with respect to fig design and nutrient content, phenology of fig ripening and the diversity of fig presentation. Whilst at a gross level there exists considerable overlap between birds, arboreal mammals and fruit bats with regard to the fig species they consume, closer analysis, based on evidence from across the tropics, suggests that discrete guilds of Ficus species differentially attract subsets of sympatric frugivore communities. This dispersal guild structure is determined by interspecific differences in fig design and presentation. Throughout our examination of the fig-frugivore interaction we consider phylogenetic factors and make comparisons between large-scale biogeographical regions. Our dataset supports previous claims that Ficus is the most important plant genus for tropical frugivores. We explore the concept of figs as keystone resources and suggest criteria for future investigations of their dietary importance. Finally, fully referenced lists of frugivores recorded at each Ficus species and of Ficus species in the diet of each frugivore are presented as online appendices. In situations where ecological information is incomplete or its retrieval is impractical, this valuable resource will assist conservationists in evaluating the role of figs or their frugivores in tropical forest sites. [source] Scaling of lactate threshold by peak oxygen uptake and by fat-free mass0·67CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 3 2007James A. Davis Summary The lactate threshold (LT) represents the onset of metabolic acidosis during cardiopulmonary exercise testing (CPET). It is measured as a O2 in the units of ml min,1. In order to make comparisons among subjects, LT is often scaled or normalized by O2 peak resulting in the LT/O2 peak ratio. Ratio variables have underlying assumptions. One assumption is that the relationship between the numerator and denominator is linear with a zero y -intercept. If the relationship has a positive y -intercept, then the ratio will decrease with increasing values of the scaling variable thereby penalizing subjects with larger values of the scaling variable. Our purpose was to examine the validity of scaling LT by O2 peak and by fat-free mass raised to 0·67 power (FFM0·67) as dimensional analysis predicts that LT is proportional to FFM0·67. Cycle ergometer CPET was administered to 204 healthy, sedentary subjects (103 males) to the limit of tolerance. Lactate threshold was estimated noninvasively using the V-slope technique. Fat-free mass was assessed by skinfolds. The relationship of LT versus O2 peak was linear with a positive y -intercept for both sexes. Consequently, the LT/O2 peak ratio decreased as O2 peak increased for both sexes. The relationship of LT versus FFM0·67was linear with a zero y -intercept for both sexes. Consequently, the plot of the LT/FFM0·67 ratio versus FFM resulted in a straight line with a slope of zero for both sexes. The results of this study support the conclusion that FFM0·67, but not O2 peak, is a valid scaling variable for LT. [source] Cross-cultural estimation of the human generation interval for use in genetics-based population divergence studiesAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2005Jack N. Fenner Abstract The length of the human generation interval is a key parameter when using genetics to date population divergence events. However, no consensus exists regarding the generation interval length, and a wide variety of interval lengths have been used in recent studies. This makes comparison between studies difficult, and questions the accuracy of divergence date estimations. Recent genealogy-based research suggests that the male generation interval is substantially longer than the female interval, and that both are greater than the values commonly used in genetics studies. This study evaluates each of these hypotheses in a broader cross-cultural context, using data from both nation states and recent hunter-gatherer societies. Both hypotheses are supported by this study; therefore, revised estimates of male, female, and overall human generation interval lengths are proposed. The nearly universal, cross-cultural nature of the evidence justifies using these proposed estimates in Y-chromosomal, mitochondrial, and autosomal DNA-based population divergence studies. Am J Phys Anthropol, 2005. © 2005 Wiley-Liss, Inc. [source] MPP programs emerging around the world19JOURNAL OF POLICY ANALYSIS AND MANAGEMENT, Issue 1 2008Iris Geva-May This paper examines public policy and management programs in Canada, Europe, Australia, and New Zealand, and makes comparisons with similar programs in the United States. Our study of public policy programs shows that there are many challenges ahead in terms of making good decisions on the form and content of programs that will add value to governments and citizens. Appropriate choices in terms of program design and pedagogy will reflect different economic, social, environmental, and cultural influences and will be shaped by history, values, and the roles of public policy and management professionals within a particular governmental context. [source] A review of the effectiveness of aspartame in helping with weight controlNUTRITION BULLETIN, Issue 2 2006A. De La Hunty Summary, Strategies to reverse the upward trend in obesity rates need to focus on both reducing energy intake and increasing energy expenditure. The provision of low- or reduced-energy-dense foods is one way of helping people to reduce their energy intake and so enable weight maintenance or weight loss to occur. The use of intense sweeteners as a substitute for sucrose potentially offers one way of helping people to reduce the energy density of their diet without any loss of palatability. This report reviews the evidence for the effect of aspartame on weight loss, weight maintenance and energy intakes in adults and addresses the question of how much energy is compensated for and whether the use of aspartame-sweetened foods and drinks is an effective way to lose weight. All studies which examined the effect of substituting sugar with either aspartame alone or aspartame in combination with other intense sweeteners on energy intake or bodyweight were identified. Studies which were not randomised controlled trials in healthy adults and which did not measure energy intakes for at least 24 h (for those with energy intakes as an outcome measure) were excluded from the analysis. A minimum of 24-h energy intake data was set as the cut-off to ensure that the full extent of any compensatory effects was seen. A total of 16 studies were included in the analysis. Of these 16 studies, 15 had energy intake as an outcome measure. The studies which used soft drinks as the vehicle for aspartame used between 500 and about 2000 ml which is equivalent to about two to six cans or bottles of soft drinks every day. A significant reduction in energy intakes was seen with aspartame compared with all types of control except when aspartame was compared with non-sucrose controls such as water. The most relevant comparisons are the parallel design studies which compare the effects of aspartame with sucrose. These had an overall effect size of 0.4 standardised difference (SD). This corresponds to a mean reduction of about 10% of energy intake. At an average energy intake of 9.3 MJ/day (average of adult men and women aged 19,50 years) this is a deficit of 0.93 MJ/day (222 kcal/day or 1560 kcal/week), which would be predicted (using an energy value for obese tissue of 7500 kcal/kg) to result in a weight loss of around 0.2 kg/week with a confidence interval 50% either side of this estimate. Information on the extent of compensation was available for 12 of the 15 studies. The weighted average of these figures was 32%. Compensation is likely to vary with a number of factors such as the size of the caloric deficit, the type of food or drink manipulated, and timescale. An estimate of the amount of compensation with soft drinks was calculated from the four studies which used soft drinks only as the vehicle. A weighted average of these figures was 15.5%. A significant reduction in weight was seen. The combined effect figure of 0.2 SD is a conservative figure as it excludes comparisons where the controls gained weight because of their high-sucrose diet and the long-term follow-up data in which the aspartame groups regained less weight than the control group. An effect of 0.2 SD corresponds to about a 3% reduction in bodyweight (2.3 kg for an adult weighing 75 kg). Given the weighted average study length was 12 weeks, this gives an estimated rate of weight loss of around 0.2 kg/week for a 75-kg adult. The meta-analyses demonstrate that using foods and drinks sweetened with aspartame instead of sucrose results in a significant reduction in both energy intakes and bodyweight. Meta-analyses both of energy intake and of weight loss produced an estimated rate of weight loss of about 0.2 kg/week. This close agreement between the figure calculated from reductions in energy intake and actual measures of weight loss gives confidence that this is a true effect. The two meta-analyses used different sets of studies with widely differing designs and controls. Although this makes comparisons between them difficult, it suggests that the final figure of around 0.2 kg/week is robust and is applicable to the variety of ways aspartame-containing foods are used by consumers. This review has shown that using foods and drinks sweetened with aspartame instead of those sweetened with sucrose is an effective way to maintain and lose weight without reducing the palatability of the diet. The decrease in energy intakes and the rate of weight loss that can reasonably be achieved is low but meaningful and, on a population basis, more than sufficient to counteract the current average rate of weight gain of around 0.007 kg/week. On an individual basis, it provides a useful adjunct to other weight loss regimes. Some compensation for the substituted energy does occur but this is only about one-third of the energy replaced and is probably less when using soft drinks sweetened with aspartame. Nevertheless, these compensation values are derived from short-term studies. More data are needed over the longer term to determine whether a tolerance to the effects is acquired. To achieve the average rate of weight loss seen in these studies of 0.2 kg/week will require around a 220-kcal (0.93 MJ) deficit per day based on an energy value for obese tissue of 7500 kcal/kg. Assuming the higher rate of compensation (32%), this would require the substitution of around 330 kcal/day (1.4 MJ/day) from sucrose with aspartame (which is equivalent to around 88 g of sucrose). Using the lower estimated rate of compensation for soft drinks alone (15.5%) would require the substitution of about 260 kcal/day (1.1 MJ/day) from sucrose with aspartame. This is equivalent to 70 g of sucrose or about two cans of soft drinks every day. [source] Evaluating the Pluses and Minuses of Custody: Sentencing Reform in England and WalesTHE HOWARD JOURNAL OF CRIMINAL JUSTICE, Issue 3 2003Julian V. Roberts This article explores three sanctions contained in the 2002 Criminal Justice Bill which follows upon the 2002 white paper Justice for All. The Bill creates a Sentencing Guidelines Council to develop sentencing guidelines, and defines three dispositions applicable to sentences of imprisonment under twelve months: ,Custody Plus', the suspended sentence of imprisonment, and the intermittent sentence of imprisonment. These reforms constitute a significant step for the sentencing process in England and Wales, and are in part a response to the 2001 Halliday Report. The changes (among others) may well have an important impact on the prison population in England and Wales, which in October 2002 reached a record level. Since the suspended sentence of imprisonment bears close resemblance to the conditional sentence of imprisonment introduced in Canada in 1996, the article makes comparisons between the two sanctions. [source] | ||||||||||||||||