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Preponderance
Kinds of Preponderance Selected AbstractsInterpreting clinical trials of diabetic dyslipidaemia: new insightsDIABETES OBESITY & METABOLISM, Issue 3 2009A. S. Wierzbicki Current treatment guidelines highlight the importance of aggressive lipid-modifying therapy in reducing cardiovascular risk in patients with type 2 diabetes. Statins are established as the cornerstone of dyslipidaemia management in diabetic patients, based on their efficacy in lowering levels of low-density lipoprotein cholesterol (LDL-C). However, statins fail to address the high residual cardiovascular risk in treated patients, some of which may be attributable to low HDL cholesterol (HDL-C) and elevated triglycerides and to a preponderance of small, dense LDL particles, indicating the need for further intervention. Fibrates are effective against all components of atherogenic dyslipidaemia associated with type 2 diabetes. Clinical studies, most notably the Fenofibrate Intervention and Event Lowering in Diabetes, indicate that fibrates, most likely in combination with a statin, have a secondary role in reducing cardiovascular risk in patients with type 2 diabetes, particularly in those without prior cardiovascular disease or patients with low HDL-C. Results are awaited from the ongoing Action to Control Cardiovascular Risk in Diabetes trial to fully evaluate the outcome benefits of this combination strategy. [source] Lipid-lowering therapy in patients with type 2 diabetes: the case for early interventionDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 4 2008Armin Steinmetz Abstract Chronic complications of type 2 diabetes, in particular, macrovascular complications, confer substantial morbidity and mortality and adversely affect a patient's quality of life. Early intensive intervention to control cardiovascular risk factors is essential in clinical management. Atherogenic dyslipidaemia characterized by elevated triglycerides, a low level of high-density lipoprotein cholesterol (HDL-C), and an increase in the preponderance of small, dense low-density lipoprotein (LDL) particles, is a key modifiable risk factor for macrovascular diabetic complications. Lowering low-density lipoprotein cholesterol (LDL-C) with a statin (or the combination of statin and ezetimibe) is the main focus for reducing cardiovascular risk in patients with diabetes. However, statins fail to address the residual cardiovascular risk associated with low HDL-C. Fibrates are effective against all components of the atherogenic dyslipidaemia associated with type 2 diabetes. Secondary analyses of the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study suggest a role for early treatment with fenofibrate in improving cardiovascular risk reduction in type 2 diabetes and provide safety data supporting the use of fenofibrate in combination with a statin. Data from the FIELD study suggest that fenofibrate may also have potential to impact on microvascular diabetic complications associated with type 2 diabetes. Data are awaited from the ongoing Action to Control Cardiovascular Risk in Diabetes (ACCORD) study to evaluate the outcome benefits of combining fenofibrate with a statin in patients with type 2 diabetes. Finally, in view of divergent study results and outstanding data, assessment of the risk of the individual with type 2 diabetes is mandatory to assist clinical decision-making when initiating lipid therapy. Copyright © 2008 John Wiley & Sons, Ltd. [source] Cardiovascular effects of the thiazolidinedionesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 2 2006Rehan Qayyum Abstract Thiazolidinediones, used for the treatment of diabetes mellitus type 2, modulate gene expression by binding to nuclear transcription factor, peroxisome proliferator-activated receptor-gamma. Peroxisome proliferator,activated receptor-gamma is expressed in several tissues, therefore, thiazolidinediones have biological effects on multiple organ systems. Here, we describe evidence that thiazolidinediones have beneficial effects on the cardiovascular system independent of their antidiabetic effect. Studies in animals have clearly shown that thiazolidinediones decrease blood pressure, left ventricular hypertrophy, development of atherosclerotic lesions, and protect myocardium from ischemia/reperfusion injury. Although relatively few studies in humans have been reported, the preponderance of available evidence suggests a beneficial effect of thiazolidinediones. Thus, by modulating gene expression, thiazolidinediones may provide a novel method for the prevention and treatment of cardiovascular diseases. Copyright © 2005 John Wiley & Sons, Ltd. [source] Gender differences in unipolar depression: an update of epidemiological findings and possible explanationsACTA PSYCHIATRICA SCANDINAVICA, Issue 3 2003C. Kuehner Objective: To give an update on epidemiological findings on sex differences in the prevalence of unipolar depression and putative risk factors. Material and methods: Systematic review of the literature. Results: Recent epidemiological research yields additional evidence for a female preponderance in unipolar depression, holding true across different cultural settings. Current explanations include artefacts, genetic, hormonal, psychological and psychosocial risk factors. Rather consistently, intrapsychic and psychosocial gender role related risk factors have been identified which may contribute to the higher depression risk in women. Gender role aspects are also reflected in endocrine stress reactions and possibly influence associated neuropsychological processes. Conclusion: There is a need for more integrative models taking into account psychological, psychosocial, and macrosocial risk factors as well as their interactions, which also connect these factors with physiological and endocrine responses. Furthermore, it is conceivable that across the life span, as well as across cultural settings, individual risk factors will add with varying emphasis to the higher prevalence of depression in women. [source] Quantitative microbial faecal source tracking with sampling guided by hydrological catchment dynamicsENVIRONMENTAL MICROBIOLOGY, Issue 10 2008G. H. Reischer Summary The impairment of water quality by faecal pollution is a global public health concern. Microbial source tracking methods help to identify faecal sources but the few recent quantitative microbial source tracking applications disregarded catchment hydrology and pollution dynamics. This quantitative microbial source tracking study, conducted in a large karstic spring catchment potentially influenced by humans and ruminant animals, was based on a tiered sampling approach: a 31-month water quality monitoring (Monitoring) covering seasonal hydrological dynamics and an investigation of flood events (Events) as periods of the strongest pollution. The detection of a ruminant-specific and a human-specific faecal Bacteroidetes marker by quantitative real-time PCR was complemented by standard microbiological and on-line hydrological parameters. Both quantitative microbial source tracking markers were detected in spring water during Monitoring and Events, with preponderance of the ruminant-specific marker. Applying multiparametric analysis of all data allowed linking the ruminant-specific marker to general faecal pollution indicators, especially during Events. Up to 80% of the variation of faecal indicator levels during Events could be explained by ruminant-specific marker levels proving the dominance of ruminant faecal sources in the catchment. Furthermore, soil was ruled out as a source of quantitative microbial source tracking markers. This study demonstrates the applicability of quantitative microbial source tracking methods and highlights the prerequisite of considering hydrological catchment dynamics in source tracking study design. [source] Prevalence, incidence, and clinical characteristics of epilepsy,A community-based door-to-door study in northern TanzaniaEPILEPSIA, Issue 10 2009Andrea S. Winkler Summary Purpose:, The main aim of this door-to-door-study was to determine the prevalence, incidence, and clinical characteristics of epilepsy in northern Tanzania. Methods:, A total of 7,399 people were screened with a standardized questionnaire using "multistage random sampling." Results:, The prevalence rate of epilepsy was 11.2/1,000 [95% confidence interval (CI) 8.9,13.9/1,000] and the age-adjusted prevalence rate was 13.2/1,000. The prevalence of active epilepsy was 8.7/1,000 (95% CI 6.7,11/1,000). There was a preponderance of women. The average retrospective incidence including the last 5 years was 81.1/100,000 (95% CI 65,101/100,000). Fifty-four percent (45 of 83) of the people with epilepsy had generalized seizures without any identifiable cause; 71% (59 of 83) of the epilepsy patients had not visited health institutions prior to the study and 76% (63 of 83) had never received treatment. Discussion:, Our study shows that the prevalence and incidence of epilepsy in northern Tanzania are higher compared to developed countries and that the majority of people with epilepsy do not access treatment. [source] Human herpes virus 6B: A possible role in epilepsy?EPILEPSIA, Issue 11 2008William H. Theodore Summary Human herpes virus 6 (HHV6) infection is nearly ubiquitous in childhood and may include central nervous system invasion. There are two variants, HHV6A and HHV6B. Usually asymptomatic, it is associated with the common, self-limited childhood illness roseola infantum and rarely with more severe syndromes. In patients with immune compromise, subsequent reactivation of viral activity may lead to severe limbic encephalitis. HHV6 has been identified as a possible etiologic agent in multiple sclerosis, myocarditis, and encephalitis. A preponderance of evidence supports an association between HHV6 and febrile seizures. An ongoing multicenter study is investigating possible links between HHV6 infection, febrile status epilepticus, and development of mesial temporal sclerosis (MTS). Investigation of temporal lobectomy specimens showed evidence of active HHV6B but not HHV6A replication in hippocampal astrocytes in about two-thirds of patients with MTS but not other causes of epilepsy. It has been suggested that HHV6B may cause "excitotoxicity" by interfering with astrocyte excitatory amino acid transport. Although conventional inflammatory changes are not found in most MTS specimens, inflammatory modulators may play a role in neuronal injury leading to MTS as well. If the link between early viral infection, complex or prolonged febrile seizures, and later development of intractable temporal lobe epilepsy is confirmed, new therapeutic approaches to a common intractable epilepsy syndrome may be possible. [source] Task-dependent modulation of functional connectivity between hand motor cortices and neuronal networks underlying language and music: a transcranial magnetic stimulation study in humansEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2007R. Sparing Abstract Although language functions are, in general, attributed to the left hemisphere, it is still a matter of debate to what extent the cognitive functions underlying the processing of music are lateralized in the human brain. To investigate hemispheric specialization we evaluated the effect of different overt musical and linguistic tasks on the excitability of both left and right hand motor cortices using transcranial magnetic stimulation (TMS). Task-dependent changes of the size of the TMS-elicited motor evoked potentials were recorded in 12 right-handed, musically naive subjects during and after overt speech, singing and humming, i.e. the production of melody without word articulation. The articulation of meaningless syllables served as control condition. We found reciprocal lateralized effects of overt speech and musical tasks on motor cortex excitability. During overt speech, the corticospinal projection of the left (i.e. dominant) hemisphere to the right hand was facilitated. In contrast, excitability of the right motor cortex increased during both overt singing and humming, whereas no effect was observed on the left hemisphere. Although the traditional concept of hemispheric lateralization of music has been challenged by recent neuroimaging studies, our findings demonstrate that right-hemisphere preponderance of music is nevertheless present. We discuss our results in terms of the recent concepts on evolution of language and gesture, which hypothesize that cerebral networks mediating hand movement and those subserving language processing are functionally linked. TMS may constitute a useful tool to further investigate the relationship between cortical representations of motor functions, music and language using comparative approaches. [source] Xenopus embryonic spinal neurons recorded in situ with patch-clamp electrodes , conditional oscillators after all?EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2003Simon P. Aiken Abstract The central pattern generator for swimming Xenopus embryo is organized as two half-centres linked by reciprocal inhibition. Microelectrode recordings suggest that Xenopus neurons are poorly excitable, necessitating a key role for postinhibitory rebound in the operation of the central pattern generator. However the Xenopus central pattern generator seems unusual in that the component neurons apparently have no intrinsic or conditional rhythmogenic properties. We have re-examined the firing properties of Xenopus embryo spinal neurons by making patch-clamp recordings in situ from intact spinal cord. Recordings made from 99 neurons were divided into three groups. Central pattern generator neurons overwhelmingly (44/51) fired trains of action potentials in response to current injection. Just over half of the sensory interneurons (13/22) also fired trains of action potentials. Neurons that received no synaptic inputs during swimming mostly fired just one or two action potentials (22/26). Thirty-four neurons were identified morphologically. Commissural (8/12) and descending (6/6) interneurons, key components of the spinal central pattern generator, fired repetitive trains of action potentials during current injection. Neurons that were not part of the central pattern generator did not demonstrate this preponderance for repetitive firing. Analysis of the interspike intervals during current injection revealed that the majority of central pattern generators, descending and commissural interneurons, could readily fire at frequencies up to twice that of swimming. We suggest that Xenopus neurons can be considered as conditional oscillators: in the presence of unpatterned excitation they exhibit an ability to fire rhythmically. This property makes the Xenopus embryonic central pattern generator more similar to other model central pattern generators than has hitherto been appreciated. [source] Attitude learning through exploration: advice and strategy appraisalsEUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 5 2007J. Richard Eiser Processes of attitude learning were investigated through a game requiring discrimination between good and bad objects, where feedback about object valence (involving gain or loss) is contingent on approach. Previous research demonstrates a preponderance of false-negative errors, with some good objects (,learning asymmetry') and most novel objects (,generalization asymmetry') being judged as bad, but provides no direct evidence concerning how participants appraise alternative strategies and their own performance. To compare alternative strategies, participants received advice, supposedly from a previous participant, that most objects were bad and should be avoided, or good and should be approached. Learning and generalization asymmetries were replicated, especially among participants who followed the former (risk-averse) advice. Additionally, participants' evaluations of their own game strategy were inversely related to amount of negative feedback (the number of bad objects approached), but unrelated to positive feedback (from good objects approached), pointing to the salience of negative information for self-appraisals. Copyright © 2007 John Wiley & Sons, Ltd. [source] Fossilized embryos are widespread but the record is temporally and taxonomically biasedEVOLUTION AND DEVELOPMENT, Issue 2 2006Philip C. J. Donoghue SUMMARY We report new discoveries of embryos and egg capsules from the Lower Cambrian of Siberia, Middle Cambrian of Australia and Lower Ordovician of North America. Together with existing records, embryos have now been recorded from four of the seven continents. However, the new discoveries highlight secular and systematic biases in the fossil record of embryonic stages. The temporal window within which the embryos and egg capsules are found is of relatively short duration; it ends in the Early Ordovician and is roughly coincident with that of typical "Orsten"-type faunas. The reduced occurrence of such fossils has been attributed to reducing levels of phosphate in marine waters during the early Paleozoic, but may also be owing to the increasing depth of sediment mixing by infaunal metazoans. Furthermore, most records younger than the earliest Cambrian are of a single kind,large eggs and embryos of the priapulid-like scalidophoran Markuelia. We explore alternative explanations for the low taxonomic diversity of embryos recovered thus far, including sampling, size, anatomy, ecology, and environment, concluding that the preponderance of Markuelia embryos is due to its precocious development of cuticle at an embryonic stage, predisposing it to preservation through action as a substrate on which microbially mediated precipitation of authigenic calcium phosphate may occur. The fossil record of embryos may be limited to a late Neoproterozoic to early Ordovician snapshot that is subject to dramatic systematic bias. Together, these biases must be considered seriously in attempts to use the fossil record to arbitrate between hypotheses of developmental and life history evolution implicated in the origin of metazoan clades. [source] Prediction of coenzyme specificity in dehydrogenases/ reductasesFEBS JOURNAL, Issue 6 2006A hidden Markov model-based method, its application on complete genomes Dehydrogenases and reductases are enzymes of fundamental metabolic importance that often adopt a specific structure known as the Rossmann fold. This fold, consisting of a six-stranded ,-sheet surrounded by ,-helices, is responsible for coenzyme binding. We have developed a method to identify Rossmann folds and predict their coenzyme specificity (NAD, NADP or FAD) using only the amino acid sequence as input. The method is based upon hidden Markov models and sequence pattern analysis. The prediction sensitivity is 79% and the selectivity close to 100%. The method was applied on a set of 68 genomes, representing the three kingdoms archaea, bacteria and eukaryota. In prokaryotes, 3% of the genes were found to code for Rossmann-fold proteins, while the corresponding ratio in eukaryotes is only around 1%. In all genomes, NAD is the most preferred cofactor (41,49%), followed by NADP with 30,38%, while FAD is the least preferred cofactor (21%). However, the NAD preponderance over NADP is most pronounced in archaea, and least in eukaryotes. In all three kingdoms, only 3,8% of the Rossmann proteins are predicted to have more than one membrane-spanning segment, which is much lower than the frequency of membrane proteins in general. Analysis of the major protein types in eukaryotes reveals that the most common type (26%) of the Rossmann proteins are short-chain dehydrogenases/reductases. In addition, the identified Rossmann proteins were analyzed with respect to further protein types, enzyme classes and redundancy. The described method is available at http://www.ifm.liu.se/bioinfo, where the preferred coenzyme and its binding region are predicted given an amino acid sequence as input. [source] Monocyte chemoattractant protein-1 (MCP-1) produced via NF-,B signaling pathway mediates migration of amoeboid microglia in the periventricular white matter in hypoxic neonatal ratsGLIA, Issue 6 2009Y. Y. Deng Abstract Monocyte chemoattractant protein-1 (MCP-1), a member of ,-chemokine subfamily, regulates the migration of microglia, monocytes, and lymphocytes to the inflammatory site in the central nervous system. We sought to determine if amoeboid microglial cells (AMC) produce MCP-1 that may be linked to migration of AMC in the corpus callosum periventricular white matter in hypoxic neonatal rats. A striking feature in 1-day-old rats subjected to hypoxia was a marked increase in cell numbers of AMC and immunoexpression of MCP-1 and its receptor (CCR2). By BrdU immunostaining, there was no significant change in the proliferation rate of AMC after hypoxic exposure when compared with the corresponding control rats. When injected intracerebrally into the corpus callosum of 7-day-old postnatal rats, MCP-1 induced the chemotactic migration of AMC to the injection site. In primary microglial cell culture subjected to hypoxia, there was a significant increase in MCP-1 release involving NF-,B signaling pathway. In in vitro chemotaxis assay, the medium derived from hypoxia-treated microglial cultures attracted more migratory microglial cells than that from the control microglial culture. The present results suggest that following a hypoxic insult, AMC in the neonatal rats increase MCP-1 production via NF-,B signaling pathway. This induces the migration and accumulation of AMC from the neighboring areas to the periventricular white matter (PWM). It is concluded that the preponderance and active migration of AMC, as well as them being the main cellular source of MCP-1, may offer an explanation for the PWM being susceptible to hypoxic damage in neonatal brain. © 2008 Wiley-Liss, Inc. [source] Prevalence of Headache in Puerto RicoHEADACHE, Issue 7 2003Héctor Miranda MD Background.,Headache is one of the most frequently reported disorders in the general adult population. Despite the fact that this disorder is common, no official estimate of the prevalence of headache exists in Puerto Rico. Purpose.,To examine the prevalence of headache and migraine, specifically, in Puerto Rico. Methods.,A telephone survey of 1610 individuals was conducted. The telephone calls were distributed using the 1990 census adjusted to the population of Puerto Rico in 1998, and according to gender, geographical area, and age. Results.,The prevalence of headache in Puerto Rico was 35.9% and migraine, in particular, 13.0%. When prevalence was fractionated by age, gender, and geographical areas, the prevalence of headache was similar for all ages, with females exhibiting a 2:1 preponderance over males. In the younger population (between 20 and 50 years of age), the female-male ratio for migraine was 3:1, and the prevalence for migraine was lower in the Metropolitan area. Conclusion.,This study, the first of its type in Puerto Rico, demonstrates that headache (and migraine specifically) is a common disorder in this country. [source] Cytotoxic T lymphocyte antigen-4 (CTLA-4) gene polymorphisms and susceptibility to type 1 autoimmune hepatitisHEPATOLOGY, Issue 1 2000Kosh Agarwal Genetic susceptibility to type 1 autoimmune hepatitis is indicated by a preponderance of female subjects and strong associations with human leukocyte antigens (HLA) DRB1*0301 and DRB1*0401. The gene encoding cytotoxic T-lymphocyte antigen-4 (CTLA-4) on chromosome 2q33 may also influence autoimmunity. To determine the frequency and significance of the exon 1 adenine (A)-guanine (G) base-exchange polymorphism for CTLA-4 in patients with type 1 autoimmune hepatitis, 155 northern European Caucasoid patients and 102 ethnically-matched control subjects were tested by polymerase chain reaction. The genotype distribution was significantly different in patients compared to controls (AA = 50/155 patients vs. 51/102 controls; AG = 84/155 patients vs. 38/102 controls; GG = 21/155 patients vs. 13/102 controls, ,2 = 8.94, P = .011). This difference was caused by a significant over-representation of the G allele in patients compared to controls (105/155 patients vs. 51/102 controls, ,2 = 8.34, P = .004, odds ratio = 2.12). The GG genotype was associated with a significantly higher mean serum aspartate transaminase level (P = .03), greater frequency of antibodies to thyroid microsomal antigens (P = .004) and was found more commonly in patients with HLADRB1*0301 (P = .02). Treatment outcomes, however, were not affected by the genotype. The CTLA-4 G allele is more common in patients with type 1 autoimmune hepatitis and may represent a second susceptibility allele. Furthermore, there may be synergy between the HLA-DRB1*0301 and the GG genotype in terms of disease risk. [source] Lymphoma risk in inflammatory bowel disease: Is it the disease or its treatment?INFLAMMATORY BOWEL DISEASES, Issue 10 2007Jennifer L. Jones MD Abstract With the increasingly widespread use of immunosuppressive and biologic agents for the treatment of Crohn's disease and ulcerative colitis come concerns about potential long-term consequences of such therapies. Disentangling the potential confounding effects of the underlying disease, its extent, severity, duration, and behavior, and concomitant medical therapy has proven to be exceedingly difficult. Unlike the case in rheumatoid arthritis, the overwhelming preponderance of population-based evidence suggests that a diagnosis of inflammatory bowel disease (IBD) is not associated with an increased relative risk of lymphoma. However, well-designed studies that evaluate the potential modifying effect of IBD severity have yet to be performed. Although the results from hospital- and population-based studies have conflicted, the results of a recent meta-analysis suggest that patients receiving purine analogs for the treatment of IBD have a lymphoma risk ,4-fold higher than expected. Analyses of lymphoma risk in patients receiving biologic agents directed against tumor necrosis factor-alpha are confounded by concomitant use of immunosuppressive agents in most of these patients. Nevertheless, there may be a small but real risk of lymphoma associated with these therapies. Although the relative risk of lymphoma may be elevated in association with some of the medical therapies used in the treatment of IBD, this absolute risk is low. Weighing the potential risk of lymphoma associated with select medical therapies against the risk of undertreating IBD will help physicians and patients to make more informed decisions pertaining to the medical management of IBD. (Inflamm Bowel Dis 2007) [source] Two cases of dermatomyofibroma (plaque-like dermal fibromatosis)INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 8 2010Elisabeth Gomez-Moyano MD Background, Dermatomyofibroma is a rare but distinct benign cutaneous mesenchymal neoplasm of fibroblastic/myofibroblastic differentiation. It is more common in adolescents and young adults, with a female preponderance. In most cases, the lesions are asymptomatic and small, measuring from 10 to 20 mm. Early and active lesions tend to be actin positive. Case report, We present a) a new case of dermatomyofibroma in an 11-month-old male infant, the youngest case reported to date, and b) the second reported case of a giant annular dermatomyofibroma, measuring 10 cm × 6 cm, in a 52-year-old woman. In both cases, histological examination showed a spindle-cell proliferation embedded among the collagen fibers of the dermis, arranged predominantly parallel to the skin surface. In both cases the spindle cells stained positive for smooth muscle actin and the elastic fibers were increased and fragmented. Conclusion, Dermatologists and pediatricians should be aware of this benign entity in order to avoid unnecessary treatment. [source] Demands of immigration among nurses from Canada and the PhilippinesINTERNATIONAL JOURNAL OF NURSING PRACTICE, Issue 2 2008Linda A Victorino Beechinor DNP APRN(BC) The purpose of this study was to describe and compare the demands of immigration on nurses from Canada and those from the Philippines, who immigrate to the USA and work in Hawaii. The findings can assist policy-makers in formulating plans to alleviate the shortage of nurses through effective immigration recruitment practices. Nurse educators can gain support for the recruitment of students from a diverse array of cultures. Managers and nursing leaders can use this information in designing recruitment, orientation, support and retention programmes for nurses that are specific to their cultural needs. The two groups of nurses were sampled from acute care staff nurse populations in Hawaii. Aroian's instrument, the Demands of Immigration scale, was used to measure and compare the distress levels of the nurses. The findings include a higher level of distress experienced by nurses from Canada compared with nurses from the Philippines. This might be attributed to a preponderance of social and collegial support available to the Philippine nurses in Hawaii where one-fourth of the population is derived from their country of origin. [source] Species,area relationships in Mediterranean-climate plant communitiesJOURNAL OF BIOGEOGRAPHY, Issue 11 2003Jon E. Keeley Abstract Aim To determine the best-fit model of species,area relationships for Mediterranean-type plant communities and evaluate how community structure affects these species,area models. Location Data were collected from California shrublands and woodlands and compared with literature reports for other Mediterranean-climate regions. Methods The number of species was recorded from 1, 100 and 1000 m2 nested plots. Best fit to the power model or exponential model was determined by comparing adjusted r2 values from the least squares regression, pattern of residuals, homoscedasticity across scales, and semi-log slopes at 1,100 m2 and 100,1000 m2. Dominance,diversity curves were tested for fit to the lognormal model, MacArthur's broken stick model, and the geometric and harmonic series. Results Early successional Western Australia and California shrublands represented the extremes and provide an interesting contrast as the exponential model was the best fit for the former, and the power model for the latter, despite similar total species richness. We hypothesize that structural differences in these communities account for the different species,area curves and are tied to patterns of dominance, equitability and life form distribution. Dominance,diversity relationships for Western Australian heathlands exhibited a close fit to MacArthur's broken stick model, indicating more equitable distribution of species. In contrast, Californian shrublands, both postfire and mature stands, were best fit by the geometric model indicating strong dominance and many minor subordinate species. These regions differ in life form distribution, with annuals being a major component of diversity in early successional Californian shrublands although they are largely lacking in mature stands. Both young and old Australian heathlands are dominated by perennials, and annuals are largely absent. Inherent in all of these ecosystems is cyclical disequilibrium caused by periodic fires. The potential for community reassembly is greater in Californian shrublands where only a quarter of the flora resprout, whereas three quarters resprout in Australian heathlands. Other Californian vegetation types sampled include coniferous forests, oak savannas and desert scrub, and demonstrate that different community structures may lead to a similar species,area relationship. Dominance,diversity relationships for coniferous forests closely follow a geometric model whereas associated oak savannas show a close fit to the lognormal model. However, for both communities, species,area curves fit a power model. The primary driver appears to be the presence of annuals. Desert scrub communities illustrate dramatic changes in both species diversity and dominance,diversity relationships in high and low rainfall years, because of the disappearance of annuals in drought years. Main conclusions Species,area curves for immature shrublands in California and the majority of Mediterranean plant communities fit a power function model. Exceptions that fit the exponential model are not because of sampling error or scaling effects, rather structural differences in these communities provide plausible explanations. The exponential species,area model may arise in more than one way. In the highly diverse Australian heathlands it results from a rapid increase in species richness at small scales. In mature California shrublands it results from very depauperate richness at the community scale. In both instances the exponential model is tied to a preponderance of perennials and paucity of annuals. For communities fit by a power model, coefficients z and log c exhibit a number of significant correlations with other diversity parameters, suggesting that they have some predictive value in ecological communities. [source] Spatial variations in the composition and abundance of zooplankton in the Bahir Dar Gulf of Lake Tana, EthiopiaAFRICAN JOURNAL OF ECOLOGY, Issue 1 2010Tunde Ohiokhioya Thadeus Imoobe Abstract The zooplankton in the littoral and open water zones of Bahir Dar Gulf, Lake Tana, collected in June and July 2007, were investigated using basic statistical measurement of diversity indices and one way analysis of variance to characterize the zooplankton fauna, with respect to its composition, abundance and spatial distribution patterns. The zooplankton composition was typical of a tropical freshwater lake, with a total of 44 species made up of sixteen rotifers, sixteen c1adocerans and twelve copepods and their developing stages in the following order of dominance; Rotifera > Cladocera > Cylopoida > Calanoida. Variation in spatial distribution was noticeable, the abundance of zooplankton was significantly higher (P < 0.05) at the littoral zone (Stations 2 and 3) than the open water (Station 1) as a result of the preponderance of the small-bodied nauplii stages, small rotifers and c1adocerans particularly Bosmina longirostris. Species richness, evenness, and diversity also increased as abundance increased in the littoral zones of the lake. The rotifers, particularly the brachionids Keratella and Brachionus spp., which are considered good indicators of lake trophic status constituted the dominant zooplankton group in terms of abundance and diversity, thus indicating that the lake has a high fisheries potential. Résumé Le zooplancton des berges et des eaux ouvertes du golfe de Bahir Dar, récolté en juin et juillet 2007 dans le lac Tana, a étéétudié en utilisant des indices de mesures statistiques de base et une analyse de la variance à une voie, pour caractériser la faune du zooplancton, tant au point de vue de la composition que de l'abondance et du schéma de distribution spatiale. La composition du zooplancton était typique d'un lac d'eau douce tropical, avec un total de 44 espèces réparties entre 16 rotifères, 16 cladocères et 12 copépodes à différents stades de développement dans l'ordre de prépondérance qui suit : Rotifères > Cladocères > Cylopoïdes > Calanoïdes. Il y avait une variation notable de la distribution spatiale : l'abondance de zooplancton était significativement plus grande (P < 0.05) dans la zone littorale (Stations 2 et 3) qu'en haute eau (Station 1), suite à la prépondérance des petits corpuscules comme les stades nauplius, les petits rotifères et cladocères, et particulièrement Bosmina longirostris. La richesse en espèces, l'uniformité et la diversité augmentaient aussi en même temps que l'abondance dans les zones littorales du lac. Les rotifères, et particulièrement Keratella et Brachionus spp., qui sont considérés comme de bons indicateurs du statut trophique du lac étaient le groupe de zooplancton dominant en termes d'abondance et de diversité, ce qui indique que le lac a un fort potentiel piscicole. [source] Ehealth: Market Potential and Business StrategiesJOURNAL OF COMPUTER-MEDIATED COMMUNICATION, Issue 4 2001Pamela Whitten Due to the economic and social priorities afforded health services in the United States, research on new delivery modalities such as the Internet is gaining in popularity. Claims of the Internet's potential range from a promise to revolutionize the fundamental way health care is delivered to a tool for empowering patients through enhanced interaction with providers (Rice, 2001). Even though a great amount of attention has been given to e-health activity, the preponderance of publications to date has focused on the Internet as a source of health information. However important this form of e-health is, this type of service simply does not face the same constraints that must be addressed by those actually delivering health care services or tightly regulated pharmaceutical products. In this paper, we examine e-health by focusing explicitly on the delivery of health care products and services. Our examination of e-health activity is guided by two broad research questions. First, we ask what the potential is for the development of online health care services by examining its potential in major health care service and product sectors. Second, based upon case studies of two online health service firms, we seek to understand the emerging strategies of firms that are attempting to enter the health care market with an entirely online approach. Our examination of current e-health trends, as well as our two case studies, demonstrates the tremendous potential for health-related commercial activity on the Internet. However, our examination of the barriers facing ehealth from the US health system also pointed out the almost insurmountable challenges. We therefore conclude that a "click and mortar" model may perhaps be the optimal strategy for e-health. [source] Evolutionary transitions among dioecy, androdioecy and hermaphroditism in limnadiid clam shrimp (Branchiopoda: Spinicaudata)JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 9 2009S. C. WEEKS Abstract Examinations of breeding system transitions have primarily concentrated on the transition from hermaphroditism to dioecy, likely because of the preponderance of this transition within flowering plants. Fewer studies have considered the reverse transition: dioecy to hermaphroditism. A fruitful approach to studying this latter transition can be sought by studying clades in which transitions between dioecy and hermaphroditism have occurred multiple times. Freshwater crustaceans in the family Limnadiidae comprise dioecious, hermaphroditic and androdioecious (males + hermaphrodites) species, and thus this family represents an excellent model system for the assessment of the evolutionary transitions between these related breeding systems. Herein we report a phylogenetic assessment of breeding system transitions within the family using a total evidence comparative approach. We find that dioecy is the ancestral breeding system for the Limnadiidae and that a minimum of two independent transitions from dioecy to hermaphroditism occurred within this family, leading to (1) a Holarctic, all-hermaphrodite species, Limnadia lenticularis and (2) mixtures of hermaphrodites and males in the genus Eulimnadia. Both hermaphroditic derivatives are essentially females with only a small amount of energy allocated to male function. Within Eulimnadia, we find several all-hermaphrodite populations/species that have been independently derived at least twice from androdioecious progenitors within this genus. We discuss two adaptive (based on the notion of ,reproductive assurance') and one nonadaptive explanations for the derivation of all-hermaphroditism from androdioecy. We propose that L. lenticularis likely represents an all-hermaphrodite species that was derived from an androdioecious ancestor, much like the all-hermaphrodite populations derived from androdioecy currently observed within the Eulimnadia. Finally, we note that the proposed hypotheses for the dioecy to hermaphroditism transition are unable to explain the derivation of a fully functional, outcrossing hermaphroditic species from a dioecious progenitor. [source] CLINICAL CHARACTERISTICS and PROGNOSIS OF COLORECTAL SIGNET-RING CELL CARCINOMAJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 2001Kook Lae Lee Background/aims, Colorectal signet-ring cell carcinoma (SRCC) is uncommon tumor. The aim of this study was to evaluate the clinical characteristics of primary and metastatic colorectal SRCC. Methods, We retrospectively examined the records of patients who had undergone surgery for colon cancer and was diagnosed pathologically as colorectal SRCC from 1988 to 2000. Results, Among 1812 patients with colorectal cancer examined, the number of patients with SRCC was 28 (1.5%); eight patients (28.6%) were metastatic and 20 patients (71.4%) were primary. Male to female ratio was 19:9 and mean age was 44.2 (primary, 42.5; metastatic, 48.3). Mean age of primary SRCC of rectosigmoid area was lower than that of ascending colon (37.4 vs. 54.5). The topographic incidences of primary SRCC were nine patients in rectum; five patients in sigmoid colon; six patients in ascending colon. Metastatic SRCC's were mostly found in splenic flexure and rectosigmoid area. Biopsy positive rate at first was 13 of 18 in primary SRCC, and 3 of 5 in metastatic SRCC. Five cases (55.6%) of primary rectal SRCC showed linitis plastica type. The stage of primary SRCC showed a preponderance of Astler,Coller C2 lesions; 3 (15%) were in B2, 1 (5%) was in C1, 14 (70%) were in C2, 2 (10%) were in D. One and two years survival of primary SRCC were 62.7 and 45.7%, respectively. Conclusions, Colorectal SRCC is rare among colon cancer and common in young age group especially which is primary or occurs in rectosigmoid area. The primary SRCC's were mostly found in advanced stage, and the prognosis might be poor. [source] Contrasting Institutional and Performance Accounts of Environmental Management Systems: Three Case Studies in the UK Water & Sewerage Industry*JOURNAL OF MANAGEMENT STUDIES, Issue 4 2007Anja Schaefer abstract This paper presents results from a longitudinal, qualitative study into the adoption of environmental management systems (EMS) in three companies in the UK water & sewerage industry. Based on institutional theory and the literature on EMS, four factors related to the adoption of EMS are identified: external and internal institutional forces, environmental performance issues, and economic performance issues. While previous literature has often assumed a balance of performance and institutional factors or a preponderance of performance factors, the results of this study indicate that institutional forces are the predominant drivers. The results further indicate that environmental performance issues become less important over time, whereas institutional drivers and economic performance rationales increase in importance over time. While conforming to institutional pressures can result in improved economic performance of a company, adoption of environmental management systems mostly on the basis of institutional and economic factors has wider repercussions for the state of corporate environmental management and progress towards greater ecological sustainability of business. [source] Granular cell tumor of the oral cavity: updated immunohistochemical profileJOURNAL OF ORAL PATHOLOGY & MEDICINE, Issue 1 2009Marilena Vered Background:, Granular cell tumor (GCT) is a benign lesion that occurs at different body sites with preponderance to the oral cavity. It is generally believed to be of schwann cell/neural cell origin. We used a large panel of both traditional and recently developed antibodies in an attempt to trace the origin of GCTs on the basis of their immunoprofile. Methods:, The patients' demographic data and the cytological and architectural features of the lesions were analyzed in a large series of oral GCTs (n = 68). Forty-two lesions were also submitted to a panel of immunohistochemical stains with antibodies against S-100, CD-68 (KP-1 and PG-M1), vimentin, calretinin, NKI/C3, PGP9.5, p75/NGFR and inhibin-,. Results:, The tongue was the most common location of oral GCTs (81%). The granular cells demonstrated a wide array of cytological features in terms of cell shape and position of the nucleus. In addition, the lesions showed different architectural patterns, including ,infiltration' with satellite nodules. Interestingly, no recurrences were reported, even in lesions that were not completely excised. Granular cells were usually found to be strongly and diffusely positive for p75, vimentin, calretinin and NKI/C3, inhibin-,, PGP9.5, and S-100. Conclusions:, Immunoreactivity of the granular cells to a broad panel of antibodies that characterize different tissues does not confirm any particular cell type for the histogenetic origin of GCTs. Furthermore, GCTs could be regarded as lesions that reflect a local metabolic or reactive change rather than a true neoplasm. [source] Clinicopathologic profile of normocomplementemic and hypocomplementemic urticarial vasculitis: a study from South IndiaJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 7 2008CVP Dincy Abstract Background, This study aims to study the clinical and histopathological characteristics of hypocomplementemic and normocomplementemic urticarial vasculitis (HUVS and NUV) among dermatology clinic attendees in a tertiary care hospital in South India. Patients and methods, A prospective study was conducted in the dermatology department from February 2003 to May 2004. Seventy-five patients met the inclusion criteria for UV. Sixty-eight patients in whom complement levels were available were classified into either NUV or HUVS groups. Clinical features, laboratory parameters and histological features were compared, and the significance of differences was established using Pearson's Chi-squared test. Results, There was a female preponderance among patients with HUVS. Wheals > 24 h were seen in 90% of patients, and in 54.4% of patients, the wheals were partially blanching or non-blanching. Angioedema was more prevalent in patients with NUV than HUVS (44.4% vs. 21.4%). Systemic involvement was seen in 64.3% of patients with HUVS and 44.4% of patients with NUV. Fever, ANA positivity and systemic lupus erythematosus (SLE) were significantly associated with HUVS. In most cases of UV, a provoking factor could not be identified. Neutrophilic small vessel vasculitis was seen in 42.9% of patients with HUVS and 16.6% patients with NUV. Direct immunofluorescence test showing immunoreactants at the dermo-epidermal junction were present in 60% of patients with HUVS and 33.3% patients with NUV. Conclusion, The clinical features of Indian patients with UV were similar to those reported from the West. Fever, ANA positivity and SLE were significantly associated with HUVS. [source] Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 36JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2003F Logullo Diabetic lumbosacral radiculoplexus neuropathy (DLRPN) is a well-recognized subacute painful asymmetric proximal and distal lower limb neuropathy. DLRPN may be associated with thoracic and upper limb involvement. The latter may appear as compression mononeuropathies and as a more diffuse disorder consistent with cervicobrachial radiculoplexus neuropathy (DCRPN). We performed a multiperspective study of patients, seen between 1999,2002, with diabetes and acute or subacute onset and progression of unilateral or asymmetric bilateral proximal and/or distal weakness in lower and/or upper limbs. We excluded patients who had compression mononeuropathies or radiculopathies, multineuropathies or asymmetric poly(radiculo)neuropathies, motor neuron disease as suggested by clinical, electrophysiological, laboratory or MRI findings. During the study period we observed 18 patients with diabetic radiculoplexus neuropathy. Most patients were middle-aged or elderly and male preponderance was noted. Ten patients had DLPRN, 6 both DLPRN and DCRPN, 2 isolated DCRPN. DCRPN affected prevalently hands and forearms, unilaterally in 3 patients, bilaterally in 5, and improved spontaneously but incompletely in most patients in several months. Pain was not a prominent feature except for one patient. We conclude that diabetic radiculoplexus neuropathy may involve the cervicobrachial regions not only in association with DLRPN but also alone. [source] The incidence of Crohn's disease in Cardiff over the last 75 years: an update for 1996,2005ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2008S. GUNESH Summary Background The incidence of Crohn's disease rose rapidly in industralized countries over the past 50 years, but it is unclear whether the incidence is still rising or has reached a plateau. Aims, To update the long-term incidence study of Crohn's disease in Cardiff for 1996,2005, to investigate whether incidence is still rising and to study changes in disease characteristics over time. Method, Crohn's cases identified by retrospective analysis of hospital records as in previous studies in Cardiff. Results, Two hundred and twelve cases were identified. Corrected incidence for this decade was 66 × 106 per year (95% confidence interval: 58,76), showing a continuing rise compared to previous decades. The proportion with colonic disease at presentation continues to rise (43%) with a corresponding fall in those with terminal ileal disease. There remains a strong female preponderance (F:M 1.6:1) as in previous studies. The incidence in children under age 16 continues to rise, and the median age at diagnosis has fallen slightly. Conclusion, Crohn's disease incidence continues to rise slowly in Cardiff with a continuing increase in those presenting with colonic disease, which is now the commonest disease pattern. [source] Hard Bargains: The Impact of Multinational Corporations on Economic Reform in Latin AmericaLATIN AMERICAN POLITICS AND SOCIETY, Issue 1 2010Patrick J. W. Egan ABSTRACT This article promotes the idea that multinational corporations have independent agency in the process of economic reform in Latin American host countries. Through a number of pooled cross-sectional time series analyses, it shows that accumulated foreign direct investment can affect policy reform in ways unanticipated by earlier theories predicated on the obsolescence of firms' influence after initial investment. The influence of firms varies across different reform areas, and competitive pressures lead firms to press alternately for liberal and illiberal reform measures. The study also considers sectoral issues, and argues that a preponderance of natural resource,oriented FDI can alter the impact of multinational investment on policy reform. Indexes of economic reform are measured against stocks of FDI and a number of political and economic control variables. Evidence shows that the dramatic increase in FDI in the region in recent years has bolstered firms' bargaining power and concomitant policy leverage. [source] Discovery of non-random spatial distribution of impacts in the Stardust cometary collectorMETEORITICS & PLANETARY SCIENCE, Issue 1-2 2008Andrew J. Westphal We also report the discovery of at least two populations of oblique tracks. We evaluate several hypotheses that could explain the observations. No hypothesis is consistent with all the observations, but the preponderance of evidence points toward at least one impact on the central Whipple shield of the spacecraft as the origin of both clustering and low-angle oblique tracks. High-angle oblique tracks unambiguously originate from a non-cometary impact on the spacecraft bus just forward of the collector. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||