Favor

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Rapid and efficient mapping of regional ventilation in the rat lung using hyperpolarized 3He with Flip angle variation for offset of RF and relaxation (FAVOR)

MAGNETIC RESONANCE IN MEDICINE, Issue 6 2008
Giles E. Santyr
Abstract A novel imaging method is presented, Flip Angle Variation for Offset of RF and Relaxation (FAVOR), for rapid and efficient measurement of rat lung ventilation using hyperpolarized helium-3 (3He) gas. The FAVOR technique utilizes variable flip angles to remove the cumulative effect of RF pulses and T1 relaxation on the hyperpolarized gas signal and thereby eliminates the need for intervening air wash-out breaths and multiple cycles of 3He wash-in breaths before each image. The former allows an improvement in speed (by a factor of ,30) while the latter reduces the cost of each measurement (by a factor of ,5). The FAVOR and conventional ventilation methods were performed on six healthy male Brown Norway rats (190,270 g). Lobar measurements of ventilation, r, obtained with the FAVOR method were not significantly different from those obtained with the conventional method for the right middle and caudal and left lobes (P > 0.05 by a Wilcoxon matched pairs test). A methacholine challenge test was also administered to an animal and reduction and recovery of r was detected by the FAVOR method. The reduced 3He consumption and the improvement in speed provided by FAVOR suggest that it may allow measurement of ventilation in human subjects not previously possible. Magn Reson Med 59:1304,1310, 2008. © 2008 Wiley-Liss, Inc. [source]


Are Paradigms Changing in Favor of Biocatalysis?

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6-7 2003
Wolf-Dieter Fessner
No abstract is available for this article. [source]


Removal of the PsaF Polypeptide Biases Electron Transfer in Favor of the PsaB Branch of Cofactors in Triton X-100 Photosystem I Complexes from Synechococcus sp.

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 6 2008
PCC 700
Continuous wave (CW) and transient electron paramagnetic resonance studies have implied that when PsaF is removed genetically, the double reduction of A1A is facile, the lifetime of A1A, is shorter and the ratio of fast to slow kinetic phases increases in PS I complexes isolated with Triton X-100 (Van der Est, A., A. I. Valieva, Y. E. Kandrashkin, G. Shen, D. A. Bryant and J. H. Golbeck [2004] Biochemistry43, 1264,1275). Changes in the lifetimes of A1A, and A1B, are characteristic of mutants involving the quinone binding sites, but changes in the relative amplitudes of A1A, and A1B, are characteristic of mutants involving the primary electron acceptors, A0A and A0B. Here, we measured the fast and slow phases of electron transfer from A1B, and A1A, to FX in psaF and psaE psaF null mutants using time-resolved CW and pump-probe optical absorption spectroscopy. The lifetime of the fast kinetic phase was found to be unaltered, but the lifetime of the slow kinetic phase was shorter in the psaF null mutant and even more so in the psaE psaF null mutant. Concomitantly, the amplitude of the fast kinetic phase increased by a factor of 1.8 and 2.0 in the psaF and psaE psaF null mutants, respectively, at the expense of the slow kinetic phase. The change in ratio of the fast to slow kinetic phases is explained as either a redirection of electron transfer through A1B at the expense of A1A, or a shortening of the lifetime of A1A, to become identical to that of A1B,. The constant lifetime and the characteristics of the near-UV spectrum of the fast kinetic phase favor the former explanation. A unified hypothesis is presented of a displacement of the A-jk(1) ,-helix and switchback loop, which would weaken the H-bond from Leu722 to A1A, accounting for the acceleration of the slow kinetic phase, as well as weaken the H-bond from Tyr696 to A0A, accounting for the bias of electron transfer in favor of the PsaB branch of cofactors. [source]


At the Time of My Need, Father Returns the Favor

ACADEMIC EMERGENCY MEDICINE, Issue 1 2008
Jonathan Singer MD
No abstract is available for this article. [source]


THE UNEMPLOYMENT PARADIGMS REVISITED: A COMPARATIVE ANALYSIS OF U.S. STATE AND EUROPEAN UNEMPLOYMENT

CONTEMPORARY ECONOMIC POLICY, Issue 3 2009
DIEGO ROMERO-ÁVILA
This article tests the main unemployment paradigms for the unemployment rates of the states of the United States and the European Union,15 countries over the past three decades. For that purpose, we employ a state-of-the-art panel stationarity test, which allows for an unknown number of endogenous structural breaks as well as for cross-sectional correlation. Overall, our analysis renders clear-cut evidence in favor of regime-wise stationarity in U.S. state unemployment, while hysteresis in European unemployment. Interestingly, the timing of the breaks broadly coincides with major macroeconomic shocks mainly associated with the oil crises of the 1970s and marked changes in interest rates in the 1980s and early 1990s. Based on our results, we draw some policy prescriptions that point to the need for greater flexibility in the European labor markets. (JEL C23, E24) [source]


Lifetime comorbidities between phobic disorders and major depression in Japan: results from the World Mental Health Japan 2002,2004 Survey,

DEPRESSION AND ANXIETY, Issue 10 2009
Masao Tsuchiya M.A.
Abstract Background: Although often considered of minor significance in themselves, evidence exists that early-onset phobic disorders might be predictors of later more serious disorders, such as major depressive disorder (MDD). The purpose of this study is to investigate the association of phobic disorders with the onset of MDD in the community in Japan. Methods: Data from the World Mental Health Japan 2002,2004 Survey were analyzed. A total of 2,436 community residents aged 20 and older were interviewed using the WHO Composite International Diagnostic Interview 3.0 (response rate, 58.4%). A Cox proportional hazard model was used to predict the onset of MDD as a function of prior history of DSM-IV specific phobia, agoraphobia, or social phobia, adjusting for gender, birth-cohort, other anxiety disorders, education, and marital status at survey. Results: Social phobia was strongly associated with the subsequent onset of MDD (hazard ratio [HR]=4.1 [95% CI: 2.0,8.7]) after adjusting for sex, birth cohort, and the number of other anxiety disorders. The association between agoraphobia or specific phobia and MDD was not statistically significant after adjusting for these variables. Conclusions: Social phobia is a powerful predictor of the subsequent first onset of MDD in Japan. Although this finding argues against a simple neurobiological model and in favor of a model in which the cultural meanings of phobia play a part in promoting MDD, an elucidation of causal pathways will require more fine-grained comparative research. Depression and Anxiety, 2009. Published 2009 Wiley-liss, Inc. [source]


Multidimensional effects of sertraline in social anxiety disorder

DEPRESSION AND ANXIETY, Issue 1 2006
Kathryn M. Connor M.D.
Abstract Clinical trials of social anxiety disorder (SAD) have largely focused on the effect of treatment on symptoms of fear and avoidance, while neglecting the third clinically relevant dimension, physiological arousal. Data were combined from two previously reported placebo-controlled trials of sertraline in the treatment of moderate-to-severe generalized SAD. Efficacy was evaluated using the Brief Social Phobia Scale (BSPS). Three hundred forty-six subjects were randomized to 12,13 weeks of treatment with sertraline and 273 subjects to placebo. Following treatment, significant improvement was noted in favor of sertraline on the full BSPS (P<.001), as well as on each of the individual BSPS subscales: fear (P=.001); avoidance (P<.0001); and physiological arousal (P<.0001). Of the physiological symptoms assessed, the treatment advantage with sertraline was maintained for blushing (P<.003) and palpitations (P<.03), but not for trembling and sweating. These results confirm the efficacy of treatment with a selective serotonin reuptake inhibitor (SSRI), sertraline, across the spectrum of fear, avoidance, and physiological arousal in generalized SAD (GSAD). Among common physiological symptoms in this population, blushing and palpitations appear more treatment responsive than trembling and sweating to acute treatment with sertraline. Depression and Anxiety 23:6,10, 2006. © 2005 Wiley-Liss, Inc. [source]


Dermoscopy provides useful information for the management of melanonychia striata

DERMATOLOGIC THERAPY, Issue 1 2007
Luc Thomas
ABSTRACT:, The diagnosis of melanonychia striata is often difficult, and a biopsy of the nail matrix is required in doubtful cases. However, dermoscopic examination of the nail plate offers interesting information in order to better select the cases in which pathologic examination is indicated. In the case of brown longitudinal pigmentation with parallel regular lines, the diagnosis of nail apparatus melanocytic nevus could be made. On the other hand, the presence of a brown pigmentation overlaid by longitudinal lines irregular in their thickness, spacing, color, or parallelism is highly in favor of a melanoma. Gray homogeneous lines are observed in case of lentigo, lentiginoses, ethnic or drug-induced pigmentations, and in post-traumatic pigmentations. Blood spots are characterized by their round-shaped proximal edge and their filamentous distal edge and are highly suggestive of subungual hemorrhages. Dermoscopic examination of the free edge of the nail plate gives information on the lesion location; pigmentation of the dorsum of the nail plate is in favor of a proximal nail matrix lesion, whereas pigmentation the lower part of the nail edge is in favor of a lesion of the distal matrix. [source]


Reducing the duration of untreated first-episode psychosis , effects on baseline social functioning and quality of life

ACTA PSYCHIATRICA SCANDINAVICA, Issue 6 2005
I. Melle
Objective:, Long duration of untreated psychosis (DUP) is associated with poorer outcome. The TIPS study demonstrated that DUP can be reduced through early detection (ED). As quality of life (QoL) is associated with DUP it is expected that reduction of DUP leads to better QoL. Method:, Consecutive first-episode patients with a DSM-IV diagnosis of non-organic, non-affective psychosis were included, 281 patients gave informed consent and 263 completed a full evaluation of QoL. Results:, There were no differences in subjective QoL between ED and No-ED groups attributable to reduction in DUP. There were significant bivariate differences in frequency of family and social contacts in favor of the ED group, but multivariate analyses indicated that these differences were based on differences in sample characteristics. Conclusion:, Deterioration in QoL may precede overt symptom formation. Focus on functional loss in ED educational campaigns may identify risk subjects earlier in the course of the disorder. [source]


Diabetic neuropathy and oxidative stress

DIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 4 2006
Rodica Pop-Busui
Abstract This review will focus on the impact of hyperglycemia-induced oxidative stress in the development of diabetes-related neural dysfunction. Oxidative stress occurs when the balance between the production of reactive oxygen species (ROS) and the ability of cells or tissues to detoxify the free radicals produced during metabolic activity is tilted in the favor of the former. Although hyperglycemia plays a key role in inducing oxidative stress in the diabetic nerve, the contribution of other factors, such as endoneurial hypoxia, transition metal imbalances, and hyperlipidemia have been also suggested. The possible sources for the overproduction of ROS in diabetes are widespread and include enzymatic pathways, auto-oxidation of glucose, and mitochondrial superoxide production. Increase in oxidative stress has clearly been shown to contribute to the pathology of neural and vascular dysfunction in diabetes. Potential therapies for preventing increased oxidative stress in diabetic nerve dysfunction will be discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Functional Interpretations of Constructive Set Theory in All Finite Types

DIALECTICA, Issue 2 2008
Justus Diller
Gödel's dialectica interpretation of Heyting arithmetic HA may be seen as expressing a lack of confidence in our understanding of unbounded quantification. Instead of formally proving an implication with an existential consequent or with a universal antecedent, the dialectica interpretation asks, under suitable conditions, for explicit ,interpreting' instances that make the implication valid. For proofs in constructive set theory CZF - , it may not always be possible to find just one such instance, but it must suffice to explicitly name a set consisting of such interpreting instances. The aim of eliminating unbounded quantification in favor of appropriate constructive functionals will still be obtained, as our ,-interpretation theorem for constructive set theory in all finite types CZF, - shows. By changing to a hybrid interpretation ,q, we show closure of CZF, - under rules that , in stronger forms , have already been studied in the context of Heyting arithmetic. In a similar spirit, we briefly survey modified realizability of CZF, - and its hybrids. Central results of this paper have been proved by Burr 2000a and Schulte 2006, however, for different translations. We use a simplified interpretation that goes back to Diller and Nahm 1974. A novel element is a lemma on absorption of bounds which is essential for the smooth operation of our translation. [source]


A study comparing tolerability, satisfaction and acceptance of three different techniques for esophageal endoscopy: sedated conventional, unsedated peroral ultra thin, and esophageal capsule

DISEASES OF THE ESOPHAGUS, Issue 5 2009
G. Nakos
SUMMARY Three methods of esophagoscopy are available until now: sedated conventional endoscopy, unsedated ultrathin endoscopy, and esophageal capsule endoscopy. The three methods carry comparable diagnostic accuracy and different complication rates. Although all of them have been found well accepted from patients, no comparative study comprising the three techniques has been published. The aim of this study was to compare the three methods of esophagoscopy regarding tolerability, satisfaction, and acceptance. Twenty patients with large esophageal varices and 10 with gastroesophageal reflux disease were prospectively included. All patients underwent consecutively sedated conventional endoscopy, unsedated ultrathin endoscopy, and esophageal capsule endoscopy. After each procedure, patients completed a seven-item questionnaire. The total positive attitude of patients toward all methods was high. However, statistical analysis revealed the following differences in favor of esophageal capsule endoscopy: (i) total positive attitude has been found higher (,2= 18.2, df = 2, P= 0.00), (ii) less patients felt pain (,2= 6.9, df = 2, P= 0.03) and discomfort (,2= 22.1, df = 2, P= 0.00), (iii) less patients experienced difficulty (,2= 13.7, df = 2, P= 0.01), and (iv) more patients were willing to undergo esophageal capsule endoscopy in the future (,2= 12.1, df = 2, P= 0.002). Esophageal capsule endoscopy was characterized by a more positive general attitude and caused less pain and discomfort. Sedated conventional endoscopy has been found more difficult. More patients would repeat esophageal capsule endoscopy in the future. Patients' total position for all three available techniques for esophageal endoscopy was excellent and renders the observed advantage of esophageal capsule endoscopy over both sedated conventional and unsedated ultrathin endoscopy a statistical finding without a real clinical benefit. [source]


Estrogen and progesterone receptors in esophageal carcinoma

DISEASES OF THE ESOPHAGUS, Issue 4 2008
R. Kalayarasan
SUMMARY., Information is sparse and contradictory in the literature regarding the role of estrogen receptor (ER) and progesterone receptor (PR) in esophageal carcinoma. This study was conducted over a period of 18 months from September 2004 with the primary aim of determining the PR, ER alpha (ER,) and ER beta (ER,) status of esophageal carcinoma and normal esophageal mucosa (NEM). The receptor status was correlated with tumor type, tumor differentiation and tumor stage. A total of 45 patients with histologically proven squamous cell carcinoma (SCC) (n = 30) and adenocarcinoma (AC) (n = 15) were studied. Receptor status was detected by immunohistochemistry (IHC) and semiquantitative assessment was done by quick score method of endoscopic biopsy specimens. The mean age for SCC and AC were not significantly different. The gender ratio in favor of males was 3 : 2 for SCC and 4 : 1 for AC. None of the specimens from SCC or AC showed positivity for PR both in NEM and tumor tissue. Likewise none of the specimens were positive for ER, by IHC. The mean ER, score for AC was significantly higher than SCC. For SCC it was seen that ER, positivity in tumor cells increases with dedifferentiation and increasing tumor stage. This trend was seen for AC as well. ER, is over-expressed in poorly differentiated SCC and AC compared to NEM. Thus ER, may be a marker for poor biological behavior, that is dedifferentiation or higher stage of disease. In view of these findings we propose a large-scale prospective, longitudinal interventional study using selective estrogen modulators. [source]


How do paedomorphic newts cope with lake drying?

ECOGRAPHY, Issue 4 2003
Mathieu Denoël
Paedomorphosis, in which adult individuals retain larval traits, is widespread in newts and salamanders. Most evolutionary models predict the maintenance of this life-history trait in favourable aquatic habitats surrounded by hostile terrestrial environments. Nevertheless, numerous ponds inhabited by paedomorphic individuals are unpredictable and temporary. In an experimental framework, I showed that paedomorphic newts were able to metamorphose and thus survive in the absence of water. However, the mere decrease of water level or the life space do not seem to induce metamorphosis in paedomorphs. On the contrary, drying up induces almost all individuals to move on land and after that to colonize other aquatic sites located nearby. Such terrestrial migrations allow survival in drying conditions without metamorphosis as long as the distances of terrestrial migration are short. These results are consistent with the presence of paedomorphs in drying ponds and are in favor of classic optimality models predicting metamorphosis in unfavorable environments. [source]


ECONOMIC GROWTH AND THE SEPARATION OF CHURCH AND STATE: THE FRENCH CASE

ECONOMIC INQUIRY, Issue 4 2010
RAPHAËL FRANCK
This article provides a test of the secularization hypothesis, which argues that economic growth, industrialization, increased literacy, and low fertility decrease religiosity. It focuses on the elections of the secular politicians who voted in favor of the separation between Church and State in the French Parliament in 1905. If the secularization hypothesis is correct, these secular politicians should have been elected in the most developed areas of France at the turn of the twentieth century. Contrary to the predictions of the secularization hypothesis, we find that the support for secular politicians originated in the rural areas of France. (JEL Z12, D72, N43) [source]


Speciation of Arsenic under Dynamic Conditions

ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 6 2008
J. Ackermann
Abstract In periodically flooded soils, reductive conditions can occur, which favor the dissolution of Fe (hydr)oxides. Fe (hydr)oxides such as goethite are important sorbents for arsenate (AsV), which is the dominant As species in soils under aerobic conditions. Hence, the dissolution of Fe (hydr)oxides under reductive conditions can result in the mobilization and reduction of AsV and, thus, in an increase in the bioavailability of arsenic. The temporal dynamics of these processes and possible re-sorption or precipitation of arsenite (AsIII) formed are poorly understood. Under controlled laboratory conditions, the temporal change in the redox potential and arsenic speciation with time after a simulated flooding event in a quartz-goethite organic matter substrate, spiked with AsV, was examined. During a period of 6,weeks, substrate solutions were sampled weekly using micro-suction cups and analyzed for pH, AsIII and AsV, Fe, Mn and P concentrations. Redox potentials and matric potentials were determined in situ in the substrate-bearing cylinders. The redox potential and the ratio between AsIII and AsV concentrations remained unchanged during the experiment without organic matter application. With organic matter applied, the redox potential decreased and the AsIII concentrations in the substrate solution increased while the total As concentrations in the substrate solution strongly decreased. An addition of goethite (1,g/kg) per se led to a decrease of the total As in the substrate solution (almost 50,%). In respect to the potential As availability for plants, and consequently, the transfer into the food chain, the results are difficult to evaluate. The lower the total As concentrations in the substrate solution, determined with decreasing redox potential, the least plant As uptake will occur. This effect may however be compensated by a shift of the molar P/AsV ratio in the solution in favor of AsV which is expected to increase the As uptake. [source]


Entrepreneurial Policy: The Case of Regional Specialization vs.

ENTREPRENEURSHIP THEORY AND PRACTICE, Issue 5 2008
Spontaneous Industrial Diversity
Regional economic development policy is recognized as a key tool governments use to foster economic prosperity. Whether specialization (or diversity) of economic activities should be a regional development policy goal is often debated. We address this question in a local-diversity context, by reviewing traditional arguments in its favor, supplemented with evidence for more entrepreneurial concepts like industrial symbiosis and Jacobs externalities. We show that the context of entrepreneurship matters more to policy than the type and form of resulting industries. Policies enabling entrepreneurs to exploit opportunities in a context of spontaneously evolved industrial diversity are better facilitators of regional development. [source]


Are there genetic influences on addiction: evidence from family, adoption and twin studies

ADDICTION, Issue 7 2008
Arpana Agrawal
ABSTRACT Aims In this exciting era of gene discovery, we review evidence from family, adoption and twin studies that examine the genetic basis for addiction. With a focus on the classical twin design that utilizes data on monozygotic and dizygotic twins, we discuss support in favor of heritable influences on alcohol, nicotine, cannabis and other illicit drug dependence. Methods We review whether these genetic factors also influence earlier stages (e.g. experimentation) of the addictive process and whether there are genetic influences specific to each psychoactive substance. Results Converging evidence from these studies supports the role of moderate to high genetic influences on addiction with estimates ranging from 0.30 to 0.70. The changing role of these heritable factors as a function of gender, age and cultural characteristics is also discussed. We highlight the importance of the interplay between genes and the environment as it relates to risk for addiction and the utility of the children-of-twins design for emerging studies of gene,environment interaction is presented. Conclusions Despite the advances being made by low-cost high-throughput whole genome association assays, we posit that information garnered from twin studies, especially extended twin designs with power to examine gene,environment interactions, will continue to form the foundation for genomic research. [source]


Placebo-corrected efficacy of modern antiepileptic drugs for refractory epilepsy: Systematic review and meta-analysis

EPILEPSIA, Issue 1 2010
Stefan Beyenburg
Summary Although adjunctive treatment with modern antiepileptic drugs (AEDs) is standard care in refractory epilepsy, it is unclear how much of the effect can be attributed directly to the AEDs and how much to the beneficial changes seen with placebo. Therefore, we performed a systematic review and meta-analysis of the evidence to determine the placebo-corrected net efficacy of adjunctive treatment with modern AEDs on the market for refractory epilepsy. Of 317 potentially eligible articles reviewed in full text, 124 (39%) fulfilled eligibility criteria. After excluding 69 publications, 55 publications of 54 studies in 11,106 adults and children with refractory epilepsy form the basis of evidence. The overall weighted pooled-risk difference in favor of AEDs over placebo for seizure-freedom in the total sample of adults and children was 6% [95% confidence interval (CI) 4,8, z = 6.47, p < 0.001] and 21% (95% CI 19,24, z = 17.13, p < 0.001) for 50% seizure reduction. Although the presence of moderate heterogeneity may reduce the validity of the results and limit generalizations from the findings, we conclude that the placebo-corrected efficacy of adjunctive treatment with modern AEDs is disappointingly small and suggest that better strategies of finding drugs are needed for refractory epilepsy, which is a major public health problem. [source]


Long-term seizure outcome of surgery versus no surgery for drug-resistant partial epilepsy: A review of controlled studies

EPILEPSIA, Issue 6 2009
Dieter Schmidt
Summary A majority of patients with formerly drug-resistant temporal lobe epilepsy become seizure-free after surgery. However, apart from one 12-month randomized trial, it is unclear how many become seizure-free because of surgery. To determine the net benefit of surgery, we performed a systematic review and meta-analysis of the published evidence of how many patients in similar studies become seizure-free without surgery. Of 155 potentially eligible articles reviewed in full text, 29 (19%) fulfilled eligibility criteria. After excluding 9 publications, 20 studies form the base of evidence. Overall, 719 of 1,621 (44%) of patients with mostly temporal lobe surgery were seizure-free compared to 139 of 1113 (12%) of nonoperated controls [pooled random effects relative risk (RR) 4.26, 95% confidence interval (CI) 3.03,5.98]. The pooled risk difference in favor of surgery was 42% (95% CI 32,51%). We found no comparative outcome data in patients with extratemporal lobe epilepsy only. The available evidence from mostly nonrandomized observational studies indicates that in appropriately selected patients with drug-resistant temporal lobe epilepsy, the combination of surgery with medical treatment is 4 times as likely as medical treatment alone to achieve freedom from seizures. [source]


Cardiac Dysrhythmia Associated with the Immediate Postictal State after Maximal Electroshock in Freely Moving Rat

EPILEPSIA, Issue 4 2002
Olivier Darbin
Summary: ,Purpose: Cardiac autonomic changes accompany complex partial seizures and generalized tonic,clonic seizures, and participate, at least partially, in the sudden and unexpected death in epilepsy (SUDEP). The analysis of the heart rate variability (HRV) is one of the simplest ways of providing insight into autonomic functions. The entropy quantifies the repetition of complex patterns in a signal and refers to systems randomness, regularity, and predictability. Clinical investigations have reported that entropy decreases in patients with a high risk of sudden cardiac death. The goal of this study was to evaluate the effects of the maximal electroshock (MES) on the entropy of HRV, monitored in the immediate postictal stage in the model of the freely moving rat. Methods: Entropy changes were correlated with the high and low frequencies of spectral analysis, which reflect the participation of the sympathetic and parasympathetic activities. Results: MES-induced arrhythmia is characterized by an HRV increase, an imbalance in favor of the parasympathetic activity, and a decrease in the entropy. Entropy decrease was restricted to the duration of the arrhythmia, suggesting that the postictal arrhythmia may be associated with a higher risk of lethal cardiac complications. Nevertheless, entropy changes did not correlate with spectral changes. Conclusions: The results suggest that the imbalance demonstrated in the spectral domain explains only partially the contribution of each autonomic system in the complexity of the heart rate during the postictal state. [source]


Population and Species Divergence of Chemical Cues that Influence Male Recognition of Females in Desmognathine Salamanders

ETHOLOGY, Issue 7 2003
Paul Verrell
Growing evidence indicates that males may be more discriminating of mating partners than often has been assumed. In the North American Ocoee dusky salamander, Desmognathus ocoee (Plethodontidae: Desmognathinae), sexual incompatibility among conspecific populations is high in encounters staged in the laboratory, at least in part because males fail to recognize ,other' females as appropriate targets for courtship. I used Y-mazes to test the hypothesis that males of D. ocoee discriminate between substrate-borne chemical cues produced by ,own' (homotypic) and ,other' (heterotypic) females. Males of four populations discriminated in favor of substrates soiled by homotypic females over clean (control) substrates (expt 1), suggesting that females produce chemical cues of sociosexual significance to males. Furthermore, males from these populations discriminated in favor of substrates soiled by homotypic females vs. substrates soiled by heterotypic females (expt 2), both conspecific and heterospecific (D. carolinensis and D. orestes). Thus, differences among populations and species in female chemical cues appear to affect the chemotactic responses of males. I suggest that, together with differences in behavioral signals and responses exhibited during courtship, differences in female chemical cues likely contribute to sexual incompatibility among populations and taxa of desmognathine salamanders. [source]


An Epidemiologic Study of Closed Emergency Department Malpractice Claims in a National Database of Physician Malpractice Insurers

ACADEMIC EMERGENCY MEDICINE, Issue 5 2010
Terrence W. Brown MD
Abstract Objectives:, The objective was to perform an epidemiologic study of emergency department (ED) medical malpractice claims using data maintained by the Physician Insurers Association of America (PIAA), a trade association whose participating malpractice insurance carriers collectively insure over 60% of practicing physicians in the United States. Methods:, All closed malpractice claims in the PIAA database between 1985 and 2007, where an event in an ED was alleged to have caused injury to a patient 18 years of age or older, were retrospectively reviewed. Study outcomes were the frequency of claims and average indemnity payments associated with specific errors identified by the malpractice insurer, as well as associated health conditions, primary specialty groups, and injury severity. Indemnity payments include money paid to claimants as a result of settlement or court adjudication, and this financial obligation to compensate a claimant constitutes the insured's financial liability. These payments do not include the expenses associated with resolving a claim, such as attorneys' fees. The study examined claims by adjudicatory outcome, associated financial liability, and expenses of litigation. Adjudicatory outcome refers to the legal disposition of a claim as it makes its way into and through the court system and includes resolution of claims by formal verdict as well as by settlement. The study also investigated how the number of claims, average indemnity payments, paid-to-close ratios (the percentage of closed claims that resolved with a payment to the plaintiff), and litigation expenses have trended over the 23-year study period. Results:, The authors identified 11,529 claims arising from an event originating in an ED, representing over $664 million in total liability over the 23-year study period. Emergency physicians (EPs) were the primary defendants in 19% of ED claims. The largest sources of error, as identified by the individual malpractice insurer, included errors in diagnosis (37%), followed by improper performance of a procedure (17%). In 18% of claims, no error could be identified by the insurer. Acute myocardial infarction (AMI; 5%), fractures (6%), and appendicitis (2%) were the health conditions associated with the highest number of claims. Over two-thirds of claims (70%) closed without payment to the claimant. Most claims that paid out did so through settlement (29%). Only 7% of claims were resolved by verdict, and 85% of those were in favor of the clinician. Over time, the average indemnity payments and expenses of litigation, adjusted for inflation, more than doubled, while both the total number of claims and number of paid claims decreased. Conclusions:, Emergency physicians were the primary defendants in a relatively small proportion of ED claims. The disease processes associated with the highest numbers of claims included AMI, appendicitis, and fractures. The largest share of overall indemnity was attributed to errors in the diagnostic process. The financial liability of medical malpractice in the ED is substantial, yet the vast majority of claims resolve in favor of the clinician. Efforts to mitigate risk in the ED should include the diverse clinical specialties who work in this complex environment, with attention to those health conditions and potential errors with the highest risk. ACADEMIC EMERGENCY MEDICINE 2010; 17:553,560 © 2010 by the Society for Academic Emergency Medicine [source]


GENETIC STUDY: Association between dopamine transporter genotypes and smoking cessation: a meta-analysis

ADDICTION BIOLOGY, Issue 2 2007
John A. Stapleton
ABSTRACT This review assessed the evidence of an association between genotypes of the dopamine transporter (DAT1, SLC6A3) 3, untranslated region (3,UTR) variable number of tandem repeats (VNTR) and smoking cessation. Five studies (seven cohorts) comprising 2155 subjects were included in the meta-analysis. All gave data on the number of smokers who had stopped smoking and the number still smoking for those with one or more variant 9-repeat alleles and other genotypes. Three studies (comprising five cohorts) were cross-sectional population surveys and two were smoking cessation treatment programs with follow-up. Four of the five studies (six of the seven cohorts) showed a trend in favor of cessation when the variant 9-repeat allele was present, although only one study showed a statistically significant effect. The pooled odds ratio in favor of a greater likelihood of cessation for the variant 9-repeat allele was 1.15 [95% confidence interval (CI) = 0.97,1.37]. In a more refined analysis where cohorts within studies were treated as separate samples and adjusted odds ratios were used, the overall pooled odds ratio in favor of cessation with the 9-repeat alleles was 1.20 (95% CI = 1.01,1.43). These results support the hypothesis that the DAT1 3,UTR VNTR polymorphism is associated with smoking cessation. One or more variant 9-repeat alleles relative to the more common 10-repeat allele confers a greater likelihood of cessation, indicative of lower dependence on tobacco. The effect was a 20% increase in the odds of cessation for those with a variant allele. [source]


On the positive side of error processing: error-awareness positivity revisited

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2009
Shani Shalgi
Abstract Performance errors are indexed in the brain even if they are not consciously registered, as demonstrated by the error-related negativity (ERN or Ne) event-related potential. It has recently been shown that another response-locked potential, the error positivity (Pe), follows the Ne, but only in those trials in which the participants consciously detect making the error (,Aware Errors'). In the present study we generalize these findings to an auditory task and investigate possible caveats in the interpretation of the Pe as an index of error awareness. In an auditory Go/No-Go error-awareness task (auditory EAT) participants pressed an additional ,fix error' button after noticing that they had made an error. As in visual tasks, the Ne was similar for aware (,fixed') and unaware (,unfixed') errors, while the Pe was enhanced only for Aware Errors. Within subjects, the Ne and Pe behaved in similar fashions for auditory and visual errors. A control condition confirmed that the awareness effect was not due to the requirement to report error awareness. These results reinforce the evidence in favor of the Pe as a correlate of conscious error processing, and imply that this process is not modality-specific. Nevertheless, single-trial analysis suggested that the Pe may be a delayed P3b related to stimulus processing rather than to response monitoring. [source]


The neuroanatomy of grapheme,color synesthesia

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2009
Lutz Jäncke
Abstract Grapheme,color synesthetes perceive particular colors when seeing a letter, word or number (grapheme). Functional neuroimaging studies have provided some evidence in favor of a neural basis for this type of synesthesia. Most of these studies have reported extra activations in the fusiform gyrus, which is known to be involved in color, letter and word processing. The present study examined different neuroanatomical features (i.e. cortical thickness, cortical volume and cortical surface area) in a sample of 48 subjects (24 grapheme,color synesthetes and 24 control subjects), and revealed increased cortical thickness, volume and surface area in the right and left fusiform gyrus and in adjacent regions, such as the lingual gyrus and the calcarine cortex, in grapheme,color synesthetes. In addition, we set out to analyze structural connectivity based on fractional anisotropy (FA) measurements in a subsample of 28 subjects (14 synesthetes and 14 control subjects). In contrast to the findings of a recent neuroanatomical study using modern diffusion tensor imaging measurement techniques, we did not detect any statistically significant difference in FA between synesthetes and non-synesthetes in the fusiform gyri. Our study thus supports the hypothesis of local anatomical differences in cortical characteristics in the vicinity of the V4 complex. The observed altered brain anatomy in grapheme,color synesthetes might be the anatomical basis for this particular form of synesthesia but it is also possible that the detected effects are a consequence (rather than the primary cause) of the life-long experience of grapheme,color synesthesia. [source]


Corticospinal control of antagonistic muscles in the cat

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2007
Christian Ethier
Abstract We recently suggested that movement-related inter-joint muscle synergies are recruited by selected excitation and selected release from inhibition of cortical points. Here we asked whether a similar cortical mechanism operates in the functional linking of antagonistic muscles. To this end experiments were done on ketamine-anesthetized cats. Intracortical microstimulation (ICMS) and intramuscular electromyographic recordings were used to find and characterize wrist, elbow and shoulder antagonistic motor cortical points. Simultaneous ICMS applied at two cortical points, each evoking activity in one of a pair of antagonistic muscles, produced co-contraction of antagonistic muscle pairs. However, we found an obvious asymmetry in the strength of reciprocal inhibition; it was always significantly stronger on physiological extensors than flexors. Following intravenous injection of a single bolus of strychnine, a cortical point at which only a physiological flexor was previously activated also elicited simultaneous activation of its antagonist. This demonstrates that antagonistic corticospinal neurons are closely grouped, or intermingled. To test whether releasing a cortical point from inhibition allows it to be functionally linked with an antagonistic cortical point, one of three GABAA receptor antagonists, bicuculline, gabazine or picrotoxin, was injected iontophoretically at one cortical point while stimulation was applied to an antagonistic cortical point. This coupling always resulted in co-contraction of the represented antagonistic muscles. Thus, antagonistic motor cortical points are linked by excitatory intracortical connections held in check by local GABAergic inhibition, with reciprocal inhibition occurring at the spinal level. Importantly, the asymmetry of cortically mediated reciprocal inhibition would appear significantly to bias muscle maps obtained by ICMS in favor of physiological flexors. [source]


ADAPTIONISM,30 YEARS AFTER GOULD AND LEWONTIN

EVOLUTION, Issue 10 2009
Rasmus Nielsen
Gould and Lewontin's 30-year-old critique of adaptionism fundamentally changed the discourse of evolutionary biology. However, with the influx of new ideas and scientific traditions from genomics into evolutionary biology, the old adaptionist controversies are being recycled in a new context. The insight gained by evolutionary biologists, that functional differences cannot be equated to adaptive changes, has at times not been appreciated by the genomics community. In this comment, I argue that even in the presence of both functional data and evidence for selection from DNA sequence data, it is still difficult to construct strong arguments in favor of adaptation. However, despite the difficulties in establishing scientific arguments in favor of specific historic evolutionary events, there is still much to learn about evolution from genomic data. [source]


ASSOCIATION BETWEEN SEX RATIO DISTORTION AND SEXUALLY ANTAGONISTIC FITNESS CONSEQUENCES OF FEMALE CHOICE

EVOLUTION, Issue 8 2009
Tim Connallon
Genetic variation can be beneficial to one sex yet harmful when expressed in the other,a condition referred to as sexual antagonism. Because X chromosomes are transmitted from fathers to daughters, and sexually antagonistic fitness variation is predicted to often be X-linked, mates of relatively low-fitness males might produce high-fitness daughters whereas mates of high-fitness males produce low-fitness daughters. Such fitness consequences have been predicted to influence the evolution of female mating biases and the offspring sex ratio. Females might evolve to prefer mates that provide good genes for daughters or might adjust offspring sex ratios in favor of the sex with the highest relative fitness. We test these possibilities in a laboratory-adapted population of Drosophila melanogaster, and find that females preferentially mate with males carrying genes that are deleterious for daughters. Preferred males produce equal numbers of sons and daughters, whereas unpreferred males produce female-biased sex ratios. As a consequence, mean offspring fitness of unpreferred males is higher than offspring fitness of preferred males. This observation has several interesting implications for sexual selection and the maintenance of population genetic variation for fitness. [source]


GENETICS AND RECENT HUMAN EVOLUTION

EVOLUTION, Issue 7 2007
Alan R. Templeton
Starting with "mitochondrial Eve" in 1987, genetics has played an increasingly important role in studies of the last two million years of human evolution. It initially appeared that genetic data resolved the basic models of recent human evolution in favor of the "out-of-Africa replacement" hypothesis in which anatomically modern humans evolved in Africa about 150,000 years ago, started to spread throughout the world about 100,000 years ago, and subsequently drove to complete genetic extinction (replacement) all other human populations in Eurasia. Unfortunately, many of the genetic studies on recent human evolution have suffered from scientific flaws, including misrepresenting the models of recent human evolution, focusing upon hypothesis compatibility rather than hypothesis testing, committing the ecological fallacy, and failing to consider a broader array of alternative hypotheses. Once these flaws are corrected, there is actually little genetic support for the out-of-Africa replacement hypothesis. Indeed, when genetic data are used in a hypothesis-testing framework, the out-of-Africa replacement hypothesis is strongly rejected. The model of recent human evolution that emerges from a statistical hypothesis-testing framework does not correspond to any of the traditional models of human evolution, but it is compatible with fossil and archaeological data. These studies also reveal that any one gene or DNA region captures only a small part of human evolutionary history, so multilocus studies are essential. As more and more loci became available, genetics will undoubtedly offer additional insights and resolutions of human evolution. [source]