3,405 research outputs found

    Mathematics difficulties in extremely preterm children : evidence of a specific deficit in basic mathematics processing

    Get PDF
    Background: Extremely preterm (EP, <26 wk gestation) children have been observed to have poor academic achievement in comparison to their term-born peers, especially in mathematics. This study investigated potential underlying causes of this difficulty. Methods: A total of 219 EP participants were compared with 153 term-born control children at 11 y of age. All children were assessed by a psychologist on a battery of standardized cognitive tests and a number estimation test assessing children’s numerical representations. Results: EP children underperformed in all tests in comparison with the term controls (the majority of Ps < 0.001). Different underlying relationships between performance on the number estimation test and mathematical achievement were found in EP as compared with control children. That is, even after controlling for cognitive ability, a relationship between number representations and mathematical performance persisted for EP children only (EP: r = 0.346, n = 186, P < 0.001; control: r = 0.095, n = 146, P = 0.256). Conclusion: Interventions for EP children may target improving children’s numerical representations in order to subsequently remediate their mathematical skills

    Heavy Carriers and Non-Drude Optical Conductivity in MnSi

    Full text link
    Optical properties of the weakly helimagnetic metal MnSi have been determined in the photon energy range from 2 meV to 4.5 eV using the combination of grazing incidence reflectance at 80 degrees (2 meV to 0.8 eV) and ellipsometry (0.8 to 4.5 eV). As the sample is cooled below 100 K the effective mass becomes strongly frequency dependent at low frequencies, while the scattering rate developes a linear frequency dependence. The complex optical conductivity can be described by the phenomenological relation \sigma(\omega,T) \propto (\Gamma(T)+i\omega)^{-1/2} used for cuprates and ruthenates.Comment: 5 pages, ReVTeX 4, 5 figures in eps forma

    Determinants of antibody persistence across doses and continents after single-dose rVSV-ZEBOV vaccination for Ebola virus disease: an observational cohort study.

    Get PDF
    BACKGROUND: The recombinant vesicular stomatitis virus (rVSV) vaccine expressing the Zaire Ebola virus (ZEBOV) glycoprotein is efficacious in the weeks following single-dose injection, but duration of immunity is unknown. We aimed to assess antibody persistence at 1 and 2 years in volunteers who received single-dose rVSV-ZEBOV in three previous trials. METHODS: In this observational cohort study, we prospectively followed-up participants from the African and European phase 1 rVSV-ZEBOV trials, who were vaccinated once in 2014-15 with 300 000 (low dose) or 10-50 million (high dose) plaque-forming units (pfu) of rVSV-ZEBOV vaccine to assess ZEBOV glycoprotein (IgG) antibody persistence. The primary outcome was ZEBOV glycoprotein-specific IgG geometric mean concentrations (GMCs) measured yearly by ELISA compared with 1 month (ie, 28 days) after immunisation. We report GMCs up to 2 years (Geneva, Switzerland, including neutralising antibodies up to 6 months) and 1 year (Lambaréné, Gabon; Kilifi, Kenya) after vaccination and factors associated with higher antibody persistence beyond 6 months, according to multivariable analyses. Trials and the observational study were registered at ClinicalTrials.gov (Geneva: NCT02287480 and NCT02933931; Kilifi: NCT02296983) and the Pan-African Clinical Trials Registry (Lambaréné PACTR201411000919191). FINDINGS: Of 217 vaccinees from the original studies (102 from the Geneva study, 75 from the Lambaréné study, and 40 from the Kilifi study), 197 returned and provided samples at 1 year (95 from the Geneva study, 63 from the Lambaréné, and 39 from the Kilifi study) and 90 at 2 years (all from the Geneva study). In the Geneva group, 44 (100%) of 44 participants who had been given a high dose (ie, 10-50 million pfu) of vaccine and who were seropositive at day 28 remained seropositive at 2 years, whereas 33 (89%) of 37 who had been given the low dose (ie, 300 000 pfu) remained seropositive for 2 years (p=0·042). In participants who had received a high dose, ZEBOV glycoprotein IgG GMCs decreased significantly between their peak (at 1-3 months) and month 6 after vaccination in Geneva (p0·05). Neutralising antibodies seem to be less durable, with seropositivity dropping from 64-71% at 28 days to 27-31% at 6 months in participants from the Geneva study. INTERPRETATION: Antibody responses to single-dose rVSV-ZEBOV vaccination are sustained across dose ranges and settings, a key criterion in countries where booster vaccinations would be impractical. FUNDING: The Wellcome Trust and Innovative Medicines Initiative 2 Joint Undertaking

    Maids, machines and morality in Brazilian homes

    Get PDF
    This paper engages with debates about the increasing use of paid domestic labour in Europe and the USA contributing with a reflection about the case of Brazil. Relations of gender, class and race are considered in the deployment of maids for housework, the patterns of consumption of household technologies and the moral reasoning of daily living with hierarchical divisions within the home. The paper considers some parallels between the Brazilian context and that of more developed countries and also the specificity of Brazil. Based on participant observation, secondary data and an ethnographic study, rich empirical data are weaved through to discuss material and moral dimensions of domestic labour and care. How does the availability of cheap domestic labour configure relations of inequality? How are social differences in the home lived with and justified? The exploration of the Brazilian case illuminates some of the problems, contradictions and possible consequences of wealthier households benefitting from the displacement of poor women that is currently happening through international migration. The paper argues that in Brazil the deflecting of tensions in gender divisions of labour in households onto a subordinate person has affected relations of equality between women and men and also the patterns of technological innovation to facilitate housework. These are outcomes to be guarded against in Europe and the United States in face of the current trends in 'global woman' relations

    Pathological and ecological host consequences of infection by an introduced fish parasite

    Get PDF
    The infection consequences of the introduced cestode fish parasite Bothriocephalus acheilognathi were studied in a cohort of wild, young-of-the-year common carp Cyprinus carpio that lacked co-evolution with the parasite. Within the cohort, parasite prevalence was 42% and parasite burdens were up to 12% body weight. Pathological changes within the intestinal tract of parasitized carp included distension of the gut wall, epithelial compression and degeneration, pressure necrosis and varied inflammatory changes. These were most pronounced in regions containing the largest proportion of mature proglottids. Although the body lengths of parasitized and non-parasitized fish were not significantly different, parasitized fish were of lower body condition and reduced weight compared to non-parasitized conspecifics. Stable isotope analysis (δ15N and δ13C) revealed trophic impacts associated with infection, particularly for δ15N where values for parasitized fish were significantly reduced as their parasite burden increased. In a controlled aquarium environment where the fish were fed ad libitum on an identical food source, there was no significant difference in values of δ15N and δ13C between parasitized and non-parasitized fish. The growth consequences remained, however, with parasitized fish growing significantly slower than non-parasitized fish, with their feeding rate (items s−1) also significantly lower. Thus, infection by an introduced parasite had multiple pathological, ecological and trophic impacts on a host with no experience of the parasite

    The pathology of familial breast cancer: The pre-BRCA1/BRCA2 era - historical perspectives

    Get PDF
    A proportion of breast carcinomas develop as a result of a genetic predispostion to the disease. Prior to cloning of the BRCA1 and BRCA2 genes a limited number of studies were carried out to identify specific histopathological characteristics of hereditary breast cancer. These studies are the subject of this review. The main finding was the association of the (atypical) medullary type of breast cancer with a family history; the most important caveat being that medullary breast cancer is found more frequently in young patients. In view of the frequent bilateral occurrence of lobular cancer, this histologic type is also likely to be associated with a predisposing genetic defect. Future investigations will have to test this hypothesis. In addition to mutations in the BRCA1 and BRCA2 genes, there are as yet unidentified genetic defects predisposing to breast cancer development, and histopathology may well help in identifying these genes in the future

    Granulomatous hepatitis due to Bartonella henselae infection in an immunocompetent patient

    Get PDF
    <p>Abstract</p> <p>Background</p> <p><it>Bartonella henselae </it>(<it>B. henselae</it>) is considered a rare cause of granulomatous hepatitis. Due to the fastidious growth characteristics of the bacteria, the limited sensitivity of histopathological stains, and the non-specific histological findings on liver biopsy, the diagnosis of hepatic bartonellosis can be difficult to establish. Furthermore, the optimal treatment of established hepatic bartonellosis remains controversial.</p> <p>Case presentation</p> <p>We present a case of hepatic bartonellosis in an immunocompetent woman who presented with right upper quadrant pain and a five cm right hepatic lobe mass on CT scan. The patient underwent a right hepatic lobectomy. Surgical pathology revealed florid necrotizing granulomatous hepatitis, favoring an infectious etiology. Despite extensive histological and serological evaluation a definitive diagnosis was not established initially. Thirteen months after initial presentation, hepatic bartonellosis was diagnosed by PCR studies from surgically excised liver tissue. Interestingly, the hepatic granulomas persisted and <it>Bartonella henselae </it>was isolated from the patient's enriched blood culture after several courses of antibiotic therapy.</p> <p>Conclusion</p> <p>The diagnosis of hepatic bartonellosis is exceedingly difficult to establish and requires a high degree of clinical suspicion. Recently developed, PCR-based approaches may be required in select patients to make the diagnosis. The optimal antimicrobial therapy for hepatic bartonellosis has not been established, and close follow-up is needed to ensure successful eradication of the infection.</p

    Protecting eyewitness evidence: Examining the efficacy of a self-administered interview tool

    Get PDF
    Given the crucial role of eyewitness evidence, statements should be obtained as soon as possible after an incident. This is not always achieved due to demands on police resources. Two studies trace the development of a new tool, the Self-Administered Interview (SAI), designed to elicit a comprehensive initial statement. In Study 1, SAI participants reported more correct details than participants who provided a free recall account, and performed at the same level as participants given a Cognitive Interview. In Study 2, participants viewed a simulated crime and half recorded their statement using the SAI. After a delay of 1 week, all participants completed a free recall test. SAI participants recalled more correct details in the delayed recall task than control participants

    Anti-müllerian hormone is not associated with cardiometabolic risk factors in adolescent females

    Get PDF
    &lt;p&gt;Objectives: Epidemiological evidence for associations of Anti-Müllerian hormone (AMH) with cardiometabolic risk factors is lacking. Existing evidence comes from small studies in select adult populations, and findings are conflicting. We aimed to assess whether AMH is associated with cardiometabolic risk factors in a general population of adolescent females.&lt;/p&gt; &lt;p&gt;Methods: AMH, fasting insulin, glucose, HDLc, LDLc, triglycerides and C-reactive protein (CRP) were measured at a mean age 15.5 years in 1,308 female participants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Multivariable linear regression was used to examine associations of AMH with these cardiometabolic outcomes.&lt;/p&gt; &lt;p&gt;Results: AMH values ranged from 0.16–35.84 ng/ml and median AMH was 3.57 ng/ml (IQR: 2.41, 5.49). For females classified as post-pubertal (n = 848) at the time of assessment median (IQR) AMH was 3.81 ng/ml (2.55, 5.82) compared with 3.25 ng/ml (2.23, 5.05) in those classed as early pubertal (n = 460, P≤0.001). After adjusting for birth weight, gestational age, pubertal stage, age, ethnicity, socioeconomic position, adiposity and use of hormonal contraceptives, there were no associations with any of the cardiometabolic outcomes. For example fasting insulin changed by 0% per doubling of AMH (95%CI: −3%,+2%) p = 0.70, with identical results if HOMA-IR was used. Results were similar after additional adjustment for smoking, physical activity and age at menarche, after exclusion of 3% of females with the highest AMH values, after excluding those that had not started menarche and after excluding those using hormonal contraceptives.&lt;/p&gt; &lt;p&gt;Conclusion: Our results suggest that in healthy adolescent females, AMH is not associated with cardiometabolic risk factors.&lt;/p&gt
    corecore