7,038 research outputs found

    Frontoparietal representations of task context support the flexible control of goal-directed cognition.

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    Cognitive control allows stimulus-response processing to be aligned with internal goals and is thus central to intelligent, purposeful behavior. Control is thought to depend in part on the active representation of task information in prefrontal cortex (PFC), which provides a source of contextual bias on perception, decision making, and action. In the present study, we investigated the organization, influences, and consequences of context representation as human subjects performed a cued sorting task that required them to flexibly judge the relationship between pairs of multivalent stimuli. Using a connectivity-based parcellation of PFC and multivariate decoding analyses, we determined that context is specifically and transiently represented in a region spanning the inferior frontal sulcus during context-dependent decision making. We also found strong evidence that decision context is represented within the intraparietal sulcus, an area previously shown to be functionally networked with the inferior frontal sulcus at rest and during task performance. Rule-guided allocation of attention to different stimulus dimensions produced discriminable patterns of activation in visual cortex, providing a signature of top-down bias over perception. Furthermore, demands on cognitive control arising from the task structure modulated context representation, which was found to be strongest after a shift in task rules. When context representation in frontoparietal areas increased in strength, as measured by the discriminability of high-dimensional activation patterns, the bias on attended stimulus features was enhanced. These results provide novel evidence that illuminates the mechanisms by which humans flexibly guide behavior in complex environments

    Specific IgE Response to Purified and Recombinant Allergens in Latex Allergy

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    Background In recent years, allergy to natural rubber latex has emerged as a major allergy among certain occupational groups and patients with underlying diseases. The sensitization and development of latex allergy has been attributed to exposure to products containing residual latex proteins. Although improved manufacturing procedures resulted in a considerable reduction of new cases, the potential risk for some patient groups is still great. In addition the prevalent cross-reactivity of latex proteins with other food allergens poses a major concern. A number of purified allergens and a few commercial kits are currently available, but no concerted effort was undertaken to evaluate them. Methods We studied 11 purified latex allergens, Hev b 1 to Hev b 10, and Hev b 13 along with several crude allergen extracts and two commercial ImmunoCAP assays to evaluate specific IgE antibody in the sera from latex allergic patients and controls. Health care workers and spina bifida patients with clinical symptoms of latex allergy, spina bifida patients without latex allergy, and non-atopic health care workers have been studied. Results The results suggest that Hev b 2, 5, 6, and 13 together identified over 80 percent health care workers with latex allergy, while Hev b 6 along with Hev b 1 or 3 detected specific IgE antibody in all sera studied from patients with spina bifida and latex allergy. The ImmunoCAP results using both Hev b 5 amplified and non-amplified closely agreed with the clinical diagnosis of latex allergy in health care workers and in spina bifida. Conclusion Although the purified allergens and crude extracts reacted diversely with IgE from different patient groups, the results indicated that use of certain combinations of purified recombinant antigens will be useful in commercial kits or in in-house assays for detecting specific IgE antibody in the sera. The results suggest that a combination of Hev b 2, 3, 5, 6, and 13 together detected specific IgE in 80% of the sera from latex allergic patients. Both ImmunoCAPs correctly identified over 95% of latex allergic patients, however, showed reactivity with a few normal control subject

    Revisiting the De-Radicalisation or Disengagement Debate: Public Attitudes to the Re-Integration of Terrorists

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    The article reports on the findings of an experimental survey which was conducted to ascertain the level of support and perceived effectiveness of using de-radicalisation programmes to re-integrate returning foreign fighters. Public support (or the lack of opposition) for re-integration programmes can be important in ensuring the programmes have the time, resources and opportunity to be successful however we know little about what wider society thinks about re-integration programmes. The article explores the extent to which the inclusion of de-radicalisation – in name and content – changes attitudes to a re-integration programme. This is relevant in showing attitudes to de-radicalisation over disengagement and whether de-radicalisation, while perhaps not more effective at the programme-level, is or is not more effective at generating public support for re-integration (and thereby facilitating the process itself). We find that the inclusion of de-radicalisation in the name and content of a re-integration programme to a small extent increases support for re-integration over a programme that uses the terms disengagement and desistance. However, we also find that while de-radicalisation increases support, it also decreases perceived effectiveness, leading respondents to feel it makes the country less safe and less likely to reduce the re-offending rate than if the programme excludes de-radicalisation. We argue this polarising effect is reflective of wider reasons for supporting the policies (e.g. de-radicalisation may be seen as a form of ideational/normative punishment) and that the term de-radicalisation may shift the framing of the problematic to entrenched social structures, thus rendering itself ineffective as a policy treatment. In terms of policy, we argue there is a necessity for greater openness about re-integration programmes and that governments would benefit from selling the programmes to the public. We conclude our paper with a justification of focusing further research on understanding public/community attitudes to re-integration programmes and understanding the PR of counter-terrorism policies more generally

    Acute Ethanol Administration Rapidly Increases Phosphorylation of Conventional Protein Kinase C in Specific Mammalian Brain Regions in Vivo

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    Background Protein kinase C (PKC) is a family of isoenzymes that regulate a variety of functions in the central nervous system including neurotransmitter release, ion channel activity, and cell differentiation. Growing evidence suggests that specific isoforms of PKC influence a variety of behavioral, biochemical, and physiological effects of ethanol in mammals. The purpose of this study was to determine whether acute ethanol exposure alters phosphorylation of conventional PKC isoforms at a threonine 674 (p-cPKC) site in the hydrophobic domain of the kinase, which is required for its catalytic activity. Methods Male rats were administered a dose range of ethanol (0, 0.5, 1, or 2 g/kg, intragastric) and brain tissue was removed 10 minutes later for evaluation of changes in p-cPKC expression using immunohistochemistry and Western blot methods. Results Immunohistochemical data show that the highest dose of ethanol (2 g/kg) rapidly increases p-cPKC immunoreactivity specifically in the nucleus accumbens (core and shell), lateral septum, and hippocampus (CA3 and dentate gyrus). Western blot analysis further showed that ethanol (2 g/kg) increased p-cPKC expression in the P2 membrane fraction of tissue from the nucleus accumbens and hippocampus. Although p-cPKC was expressed in numerous other brain regions, including the caudate nucleus, amygdala, and cortex, no changes were observed in response to acute ethanol. Total PKC? immunoreactivity was surveyed throughout the brain and showed no change following acute ethanol injection

    Photonics - An atomic dimmer switch

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62775/1/396217a0.pd

    Fingertip force control during bimanual object lifting in hemiplegic cerebral palsy

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    In the present study we examined unimanual and bimanual fingertip force control during grasping in children with hemiplegic cerebral palsy (CP). Participants lifted, transported and released an object with one hand or both hands together in order to examine the effect on fingertip force control for each hand separately and to determine whether any benefit exists for the affected hand when it performed the task concurrently with the less-affected hand. Seven children with hemiplegic CP performed the task while their movement and fingertip force control were measured. In the bimanual conditions, the weight of the instrumented objects was equal or unequal. The durations of the all temporal phases for the less-affected hand were prolonged during bimanual control compared to unimanual control. We observed close synchrony of both hands when the task was performed with both hands, despite large differences in duration between both hands when they performed separately. There was a marginal benefit for two of the five force related variables for the affected hand (grip force at onset of load force, and peak grip force) when it transported the object simultaneously with the less-affected hand. Collectively, these results corroborate earlier findings of reaching studies that showed slowing down of the less-affected hand when it moved together with the affected hand. A new finding that extends these studies is that bimanual tasks may have the potential to facilitate force control of the affected hand. The implications of these findings for recent rehabilitative therapies in children with CP that make use of bimanual training are discussed

    Hypothermia and Fever After Organophosphorus Poisoning in Humans—A Prospective Case Series

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    There have been many animal studies on the effects of organophosphorus pesticide (OP) poisoning on thermoregulation with inconsistent results. There have been no prospective human studies. Our aim was to document the changes in body temperature with OP poisoning. A prospective study was conducted in a rural hospital in Polonnaruwa, Sri Lanka. We collected data on sequential patients with OP poisoning and analyzed 12 patients selected from 53 presentations who had overt signs and symptoms of OP poisoning and who had not received atropine prior to arrival. All patients subsequently received specific management with atropine and/or pralidoxime and general supportive care. Tympanic temperature, ambient temperature, heart rate, and clinical examination and interventions were recorded prospectively throughout their hospitalization. Initial hypothermia as low as 32°C was observed in untreated patients. Tympanic temperature increased over time from an early hypothermia (<35°C in 6/12 patients) to later fever (7/12 patients >38°C at some later point). While some of the late high temperatures occurred in the setting of marked tachycardia, it was also apparent that in some cases fever was not accompanied by tachycardia, making excessive atropine or severe infection an unlikely explanation for all the fevers. In humans, OP poisoning causes an initial hypothermia, and this is followed by a period of normal to high body temperature. Atropine and respiratory complications may contribute to fever but do not account for all cases

    PCV13 induced IgG responses in serum associate with serotype-specific IgG in the lung

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    Pneumococcal conjugate vaccine efficacy is lower for non-invasive pneumonia than invasive disease. In this study, participants were vaccinated with PCV13 or HepA (control). Bronchoalveolar lavage samples were taken between 2-6 months and serum at 4- and 7-weeks post vaccination. In the lung, anti-capsular IgG levels were higher in the PCV13 group compared to control for all serotypes, except 3 and 6B. Systemically, IgG levels were elevated in the PCV group at 4-weeks for all serotypes, except 3. IgG in BAL and serum positively correlated for nearly all serotypes. PCV13 shows poor immunogenicity to serotype 3, implying lack of protective efficacy. Clinical trial registration with ISRCTN: 4534043

    Hepatitis B vaccination impact and the unmet need for antiviral treatment in Blantyre, Malawi

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    BACKGROUND: Hepatitis B is the leading cause of cirrhosis and liver cancer in sub-Saharan Africa. To reduce hepatitis-associated mortality, antiviral treatment programmes are needed. We estimated prevalence, vaccine impact and need for antiviral treatment in Blantyre, Malawi to inform an effective public health response. METHODS: We conducted a household study in Blantyre in 2016-2018. We selected individuals from a census using random sampling and estimated age-sex-standardised HBsAg seroprevalence. Impact of infant hepatitis B vaccination, which began in 2002, was estimated by binomial log-linear regression comparing individuals born before and after vaccine implementation. In HBsAg-positive adults, eligibility for antiviral therapy was assessed. RESULTS: Of 97,386 censused individuals, 6,073 (median age 18 years; 56.7% female) were sampled. HBsAg seroprevalence was 5.1% (95% CI 4.3-6.1) among adults and 0.3% (0.1-0.6) among children born after vaccine introduction. Estimated vaccine impact was 95.8% (70.3-99.4). Of HBsAg-positive adults, 26% were HIV-positive. Among HIV-negative individuals, 3%, 6% and 9% were eligible for hepatitis B treatment by WHO, European and American hepatology association criteria, respectively. CONCLUSIONS: Infant HBV vaccination has been highly effective in reducing HBsAg prevalence in urban Malawi. Up to 9% of HBsAg-positive HIV-negative adults are eligible, but have an unmet need, for antiviral therapy

    Caspase-2 is upregulated after sciatic nerve transection and its inhibition protects dorsal root ganglion neurons from Apoptosis after serum withdrawal

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    Sciatic nerve (SN) transection-induced apoptosis of dorsal root ganglion neurons (DRGN) is one factor determining the efficacy of peripheral axonal regeneration and the return of sensation. Here, we tested the hypothesis that caspase-2(CASP2) orchestrates apoptosis of axotomised DRGN both in vivo and in vitro by disrupting the local neurotrophic supply to DRGN. We observed significantly elevated levels of cleaved CASP2 (C-CASP2), compared to cleaved caspase-3 (C-CASP3), within TUNEL+DRGN and DRG glia (satellite and Schwann cells) after SN transection. A serum withdrawal cell culture model, which induced 40% apoptotic death in DRGN and 60% in glia, was used to model DRGN loss after neurotrophic factor withdrawal. Elevated C-CASP2 and TUNEL were observed in both DRGN and DRG glia, with C-CASP2 localisation shifting from the cytosol to the nucleus, a required step for induction of direct CASP2-mediated apoptosis. Furthermore, siRNAmediated downregulation of CASP2 protected 50% of DRGN from apoptosis after serum withdrawal, while downregulation of CASP3 had no effect on DRGN or DRG glia survival. We conclude that CASP2 orchestrates the death of SN-axotomised DRGN directly and also indirectly through loss of DRG glia and their local neurotrophic factor support. Accordingly, inhibiting CASP2 expression is a potential therapy for improving both the SN regeneration response and peripheral sensory recovery
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