433 research outputs found

    A 19-channel d.c. SQUID magnetometer system for brain research

    Get PDF
    A 19-channel d.c. SQUID magnetometer system for neuromagnetic investigations is under constuction. The first-order gradiometers for sensing the signal are placed in a hexagonal configuration. D.c. SQUIDs based on niobium/aluminium technology have been developed, leading to a field sensitivity of about 5 fT/ Hz. SQUID read-out is realized with a resonant transformer circuit at 100 kHz. The multichannel control and detection electronics are compactly built

    Ueber Eiweissumsatz und -Ansatz bei der Muskelarbeit

    Get PDF
    n/

    Video Review of Baseline Performance on Global Ratings in a Doubleā€Blind Placebo Surgery Trial

    Get PDF
    BACKGROUND A randomized doubleā€blind sham surgeryā€controlled trial was conducted to determine the effectiveness of implantation of human embryonic dopamine neurons into the putamen of patients with advanced Parkinson\u27s disease (PD). The present analyses determined whether patients viewing a video of themselves performing motor activities off medications at baseline would affect selfā€ratings 12 months later on the Global Rating Scale (GRS). OBJECTIVES To examine changes in GRS scores preā€/postā€video review for the total sample; to examine differences in scores between actual implant and sham groups, as well as perceived groups preā€ and postā€video review; to examine differences among four subgroups of patients based on actual and perceived treatment (i.e., actual implant/perceived implant). METHODS Forty participants were recruited and randomly assigned to receive either neural implantation or sham surgery. The primary outcome variable was a oneā€item GRS ranging from ā€3 (much worse since surgery) to +3 (much improved since surgery). At 12 months (before the blind was lifted) patients rated themselves on the GRS before and after viewing the baseline video. RESULTS Total sample GRS scores improved after the video (P = .001). There were no differences between the actual implant and sham groups before or after the video, but there were differences between perceived groups at both times (P \u3c .001). Among subgroups, improvement after the video was found only in the group receiving the implant but who thought sham (P = .011). CONCLUSION When selfā€ratings are an outcome variable, review of baseline videos is recommended before making comparative ratings

    Die EuropƤisierung der ƶffentlichen Aufgaben

    Get PDF
    Die zunehmende EuropƤisierung der ƶffentlichen Aufgaben ist einer der wichtigsten Trends im Wandel der StaatstƤtigkeit in der Bundesrepublik Deutschland und in anderen Mitgliedstaaten der EuropƤischen Union. In diesem Essay werden die Stufen der EuropƤisierung der StaatstƤtigkeit nachgezeichnet, in WeiterfĆ¼hrung von Lindberg/Scheingold (1970) und Schmitter (1996) quantifiziert und hinsichtlich ihrer Kosten und ihres Nutzen erƶrtert. Inhalt: Stufen der EuropƤisierung der ƶffentlichen Aufgaben Der EuropƤisierungsgrad der ƶffentlichen Aufgaben von 1950 bis zum Ende des 20. Jahrhunderts Vom Nutzen und von den Kosten der EuropƤisierung der ƶffentlichen Angelegenheiten Verzeichnis der zitierten Literatu

    Behavior and Impact of Zirconium in the Soilā€“Plant System: Plant Uptake and Phytotoxicity

    Get PDF
    Because of the large number of sites they pollute, toxic metals that contaminate terrestrial ecosystems are increasingly of environmental and sanitary concern (Uzu et al. 2010, 2011; Shahid et al. 2011a, b, 2012a). Among such metals is zirconium (Zr), which has the atomic number 40 and is a transition metal that resembles titanium in physical and chemical properties (Zaccone et al. 2008). Zr is widely used in many chemical industry processes and in nuclear reactors (Sandoval et al. 2011; Kamal et al. 2011), owing to its useful properties like hardness, corrosion-resistance and permeable to neutrons (Mushtaq 2012). Hence, the recent increased use of Zr by industry, and the occurrence of the Chernobyl and Fukashima catastrophe have enhanced environmental levels in soil and waters (Yirchenko and Agapkina 1993; Mosulishvili et al. 1994 ; Kruglov et al. 1996)

    Mechanisms Promoting the Long-Term Persistence of a Wolbachia Infection in a Laboratory-Adapted Population of Drosophila melanogaster

    Get PDF
    Intracellular bacteria of the genus Wolbachia are widespread endosymbionts across diverse insect taxa. Despite this prevalence, our understanding of how Wolbachia persists within populations is not well understood. Cytoplasmic incompatibility (CI) appears to be an important phenotype maintaining Wolbachia in many insects, but it is believed to be too weak to maintain Wolbachia in Drosophila melanogaster, suggesting that Wolbachia must also have other effects on this species. Here we estimate the net selective effect of Wolbachia on its host in a laboratory-adapted population of D. melanogaster, to determine the mechanisms leading to its persistence in the laboratory environment. We found i) no significant effects of Wolbachia infection on female egg-to-adult survival or adult fitness, ii) no reduced juvenile survival in males, iii) substantial levels of CI, and iv) a vertical transmission rate of Wolbachia higher than 99%. The fitness of cured females was, however, severely reduced (a decline of 37%) due to CI in offspring. Taken together these findings indicate that Wolbachia is maintained in our laboratory environment due to a combination of a nearly perfect transmission rate and substantial CI. Our results show that there would be strong selection against females losing their infection and producing progeny free from Wolbachia

    Life and Death of an Influential Passenger: Wolbachia and the Evolution of CI-Modifiers by Their Hosts

    Get PDF
    Wolbachia are intracellular bacteria widely distributed among arthropods and nematodes. In many insect species these bacteria induce a cytoplasmic incompatibility (CI) between sperm of infected males and eggs of uninfected females. From an evolutionary point of view, CI is puzzling: In order to induce this modification-rescue system, Wolbachia affect sperm of infected males even though Wolbachia are only transmitted maternally. Phylogenetic studies of Wolbachia and hosts show that the bacteria rarely cospeciate with their hosts, indicating that infections are lost in host species. However, the mechanisms leading to Wolbachia loss are not well understood.Using a population genetic model, we investigate the spread of host mutants that enhance or repress Wolbachia action by affecting either bacterial transmission or the level of CI. We show that host mutants that decrease CI-levels in males (e.g. by reducing Wolbachia-density during spermatogenesis) spread, even at cost to mutant males. Increase of these mutants can lead to loss of Wolbachia infections, either as a direct consequence of their increase or in a step-wise manner, and we derive analytically a threshold penetrance above which a mutation's spread leads to extinction of Wolbachia. Selection on host modifiers is sexually antagonistic in that, conversely, host mutants that enhance Wolbachia in females are favoured whereas suppressors are not.Our results indicate that Wolbachia is likely to be lost from host populations on long evolutionary time scales due to reduction of CI levels in males. This can occur either by evolution of single host modifiers with large effects or through accumulation of several modifier alleles with small effects on Wolbachia action, even at cost to mutant males and even if infected hosts do not incur fecundity costs. This possibility is consistent with recent findings and may help to explain the apparent short evolutionary persistence times of Wolbachia in many host systems

    Comorbid substance abuse and brain morphology in recent-onset psychosis

    Get PDF
    The aim of the presented study was to compare schizophrenia and schizoaffective patients early in the course of the disease with and without comorbid substance abuse disorder (SUD vs. NSUD) with regard to brain morphology. In a prospective design 41 patients (20 SUD vs. 21 NSUD) diagnosed as recent-onset schizophrenia or schizoaffective disorder consecutively admitted to hospital received standardized psychopathological evaluation (BPRS, SANS, MADRS, CGI, GAF) and MRI scanning with volumetric measurement of superior temporal gyrus (STG), amygdala-hippocampal complex, and cingulum. Patients with SUD (primarily cannabis) were significantly younger, predominantly male and had a lower socioeconomic status. Despite less attentional impairment (SANS subscore) and elevated anxiety/depression (BPRS subscore) in patients with SUD compared to NSUD, no other psychopathological differences could be detected. There were no differences in the assessed temporolimbic brain morphology between the two subgroups. In conclusion, in this study substance abuse in recent-onset psychosis had no effect on brain morphology and the earlier onset of psychosis in patients with comorbid SUD could not be explained by supposed accentuated brain abnormalities in temporolimbic regions

    Wolbachia infections that reduce immature insect survival: Predicted impacts on population replacement

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The evolutionary success of <it>Wolbachia </it>bacteria, infections of which are widespread in invertebrates, is largely attributed to an ability to manipulate host reproduction without imposing substantial fitness costs. Here, we describe a stage-structured model with deterministic immature lifestages and a stochastic adult female lifestage. Simulations were conducted to better understand <it>Wolbachia </it>invasions into uninfected host populations. The model includes conventional <it>Wolbachia </it>parameters (the level of cytoplasmic incompatibility, maternal inheritance, the relative fecundity of infected females, and the initial <it>Wolbachia </it>infection frequency) and a new parameter termed relative larval viability (<it>RLV</it>), which is the survival of infected larvae relative to uninfected larvae.</p> <p>Results</p> <p>The results predict the <it>RLV </it>parameter to be the most important determinant for <it>Wolbachia </it>invasion and establishment. Specifically, the fitness of infected immature hosts must be close to equal to that of uninfected hosts before population replacement can occur. Furthermore, minute decreases in <it>RLV </it>inhibit the invasion of <it>Wolbachia </it>despite high levels of cytoplasmic incompatibility, maternal inheritance, and low adult fitness costs.</p> <p>Conclusions</p> <p>The model described here takes a novel approach to understanding the spread of <it>Wolbachia </it>through a population with explicit dynamics. By combining a stochastic female adult lifestage and deterministic immature/adult male lifestages, the model predicts that even those <it>Wolbachia </it>infections that cause minor decreases in immature survival are unlikely to invade and spread within the host population. The results are discussed in relation to recent theoretical and empirical studies of natural population replacement events and proposed applied research, which would use <it>Wolbachia </it>as a tool to manipulate insect populations.</p
    • ā€¦
    corecore