1,283 research outputs found
Impaired desynchronization of beta activity underlies memory deficits in people with Parkinson's disease
Subsonic high-angle-of-attack aerodynamic characteristics of a cone and cylinder with triangular cross sections and a cone with a square cross section
Experiments were conducted in the 12-Foot Pressure Wind Tunnel at Ames Research Center on three models with noncircular cross sections: a cone having a square cross section with rounded corners and a cone and cylinder with triangular cross sections and rounded vertices. The cones were tested with both sharp and blunt noses. Surface pressures and force and moment measurements were obtained over an angle of attack range from 30 deg to 90 deg and selected oil-flow experiments were conducted to visualize surface flow patterns. Unit Reynolds numbers ranged from 0.8x1,000,000/m to 13.0x1,000,000/m at a Mach number of 0.25, except for a few low-Reynolds-number runs at a Mach number of 0.17. Pressure data, as well as force data and oil-flow photographs, reveal that the three dimensional flow structure at angles of attack up to 75 deg is very complex and is highly dependent on nose bluntness and Reynolds number. For angles of attack from 75 deg to 90 deg the sectional aerodynamic characteristics are similar to those of a two dimensional cylinder with the same cross section
Sex-Based Biomechanical Models Impact Knee Joint Moments
Joint kinetic analysis is dependent on accurate link-segment models. Considering the current default model may not account for female segment anthropometry, we sought to develop and test sex-specific biomechanical models. We hypothesize that a sex-based biomechanical model would produce a significant alteration in hip, knee, and ankle joint moments compared to default model for females, but not males. Fourteen female and 18 male participants had hip, knee, and ankle joint moments quantified during running (4.0 m/s) using both a default and sex-based (both male and female) biomechanical model. Peak hip, knee and ankle joint moments were submitted to paired t-tests to compare the default and sex-based model measurements. Contrary to our hypothesis, both male and female sex-based models altered lower limb joint moments compared to the default model. Both the male and female sex-based model produced larger hip (p \u3c 0.011; p \u3c 0.032), but smaller ankle joint moments (p \u3c 0.023; p\u3c 0.001); while the sex-based knee joint moments were smaller for males (p \u3c 0.036) and larger for females (p \u3c 0.049). The current findings support the need for sex-based biomechanical models
Case report: a diagnostically challenging conjunctival mass caused by the Epstein-Barr virus.
We present a paediatric case of infectious mononucleosis in a 13-year old, manifesting with follicular conjunctivitis and a conjunctival mass in one eye with no evidence of leucocytosis on the blood count. The diagnosis was confirmed following surgical excision and biopsy. The case represented a diagnostic challenge due to its atypism and given the steady increase in the prevalence of EBV-related ocular diseases in the last years, this report can serve as an example to prompt earlier serological tests to identify the aetiology in similar cases. This is important because EBV can be treated with acyclovir early in the active viral phase
Infrared High-Resolution Spectroscopy of Post-AGB Circumstellar Disks. I. HR 4049 - The Winnowing Flow Observed?
High-resolution infrared spectroscopy in the 2.3-4.6 micron region is
reported for the peculiar A supergiant, single-lined spectroscopic binary HR
4049. Lines from the CO fundamental and first overtone, OH fundamental, and
several H2O vibration-rotation transitions have been observed in the
near-infrared spectrum. The spectrum of HR 4049 appears principally in emission
through the 3 and 4.6 micron region and in absorption in the 2 micron region.
The 4.6 micron spectrum shows a rich 'forest' of emission lines. All the
spectral lines observed in the 2.3-4.6 micron spectrum are shown to be
circumbinary in origin. The presence of OH and H2O lines confirm the
oxygen-rich nature of the circumbinary gas which is in contrast to the
previously detected carbon-rich material. The emission and absorption line
profiles show that the circumbinary gas is located in a thin, rotating layer
near the dust disk. The properties of the dust and gas circumbinary disk and
the spectroscopic orbit yield masses for the individual stars, M_AI~0.58 Msolar
and M_MV~0.34 Msolar. Gas in the disk also has an outward flow with a velocity
of 1 km/s. The severe depletion of refractory elements but near-solar
abundances of volatile elements observed in HR 4049 results from abundance
winnowing. The separation of the volatiles from the grains in the disk and the
subsequent accretion by the star are discussed. Contrary to prior reports, the
HR 4049 carbon and oxygen isotopic abundances are typical AGB values:
12C/13C=6^{+9}_{-4} and 16O/17O>200.Comment: 42 pages, 14 figures, Accepted by Ap
The state of play between managing major sport events and human rights:a scoping review
This scoping review integrates literature from diverse perspectives to better understand when and how management of major sport events promotes or harms human rights. The authors critically review 130 peer-reviewed English language articles to identify conceptual contributions to research and practice. The findings reveal that politics and political reform, legal frameworks, and organizational actions are crucial influences in when and how management of events promotes or harms human rights. The most frequently considered rights in the literature are: equality, human trafficking related, sport as a human right, worker rights, and freedom of residence. Activism for human rights stimulates change within relevant stakeholders via collaboration, naming and shaming, in-public debates, and media coverage. The committed, transparent, and inclusive consideration of human rights in all stages of managing sport events (from bid preparation, bidding, planning, and hosting to postevent leverage) may increase the likelihood that the event has social benefits
The neonicotinoid insecticide Imidacloprid repels pollinating flies and beetles at field-realistic concentrations
Neonicotinoids are widely used systemic insecticides which, when applied to flowering crops, are translocated to the nectar and pollen where they may impact upon pollinators. Given global concerns over pollinator declines, this potential impact has recently received much attention. Field exposure of pollinators to neonicotinoids depends on the concentrations present in flowering crops and the degree to which pollinators choose to feed upon them. Here we describe a simple experiment using paired yellow pan traps with or without insecticide to assess whether the commonly used neonicotinoid imidacloprid repels or attracts flying insects. Both Diptera and Coleoptera exhibited marked avoidance of traps containing imidacloprid at a field-realistic dose of 1 μg L-1, with Diptera avoiding concentrations as low as 0.01 μg L-1. This is to our knowledge the first evidence for any biological activity at such low concentrations, which are below the limits of laboratory detection using most commonly available techniques. Catch of spiders in pan traps was also slightly reduced by the highest concentrations of imidacloprid used (1 μg L-1), but catch was increased by lower concentrations. It remains to be seen if the repellent effect on insects occurs when neonicotinoids are present in real flowers, but if so then this could have implications for exposure of pollinators to neonicotinoids and for crop pollination. © 2013 Easton, Goulson
High HIV prevalence in an early cohort of hospital admissions with COVID-19 in Cape Town, South Africa
Background. South Africa (SA) has a high prevalence of HIV and tuberculosis. Cape Town was the SA metropole most affected in the early stages of the COVID-19 pandemic. Early observational data from Africa may provide valuable insight into what can be expected as the pandemic expands across the continent.Objectives. To describe the prevalence, clinical features, comorbidities and outcome of an early cohort of HIV-positive and HIV-negative patients admitted with COVID-19.Methods. This was a descriptive observational study of an early cohort of adults with COVID-19 pneumonia admitted from 25 March to 11 May 2020.Results. Of 116 patients (mean age 48 years, 61% female) admitted, 24 were HIV-positive (21%). The most common symptoms reported were cough (n=88; 73%), shortness of breath (n=78; 69%), fever (n=67; 59%), myalgia (n=29; 25%) and chest pain (n=22; 20%). The most common comorbidities were hypertension (n=46; 41%), diabetes mellitus (n=43; 38%), obesity (n=32; 28%) and HIV (n=24; 21%). Mortality was associated with older age (mean (standard deviation) 55 (12) years v. 46 (14) years; p<0.01); the presence of hypertension or hypertension along with diabetes and/or obesity; lower partial pressure of arterial oxygen to fraction of inspired oxygen ratio; and higher urea level, white cell count, neutrophil count, and C-reactive protein, lactate dehydrogenase and ferritin levels, and high neutrophil to lymphocyte ratio. The overall survival rate for all hospital admissions was 86/116 (73%). In this early cohort, survival was similar in patients with HIV (n=18; 75%) compared with those without HIV (n=67; 75%) (p=1). Of the 74 patients admitted to the wards, 63 (85%) survived, whereas 22 of 42 (52%) admitted to the intensive care unit survived.Conclusions. Patients with HIV infection represented a large proportion of all COVID-19 admissions. The presentation and outcome of patients with HIV did not differ significantly from those of patients without HIV
Improving diagnosis and broadening the phenotypes in early-onset seizure and severe developmental delay disorders through gene panel analysis
BACKGROUND: We sought to investigate the diagnostic yield and mutation spectrum in previously reported genes for early-onset epilepsy and disorders of severe developmental delay. METHODS: In 400 patients with these disorders with no known underlying aetiology and no major structural brain anomaly, we analysed 46 genes using a combination of targeted sequencing on an Illumina MiSeq platform and targeted, exon-level microarray copy number analysis. RESULTS: We identified causative mutations in 71/400 patients (18%). The diagnostic rate was highest among those with seizure onset within the first two months of life (39%), although overall it was similar in those with and without seizures. The most frequently mutated gene was SCN2A (11 patients, 3%). Other recurrently mutated genes included CDKL5, KCNQ2, SCN8A (six patients each), FOXG1, MECP2, SCN1A, STXBP1 (five patients each), KCNT1, PCDH19, TCF4 (three patients each) and ATP1A3, PRRT2 and SLC9A6 (two patients each). Mutations in EHMT1, GABRB3, LGI1, MBD5, PIGA, UBE3A and ZEB2 were each found in single patients. We found mutations in a number of genes in patients where either the electroclinical features or dysmorphic phenotypes were atypical for the identified gene. In only 11 cases (15%) had the clinician sufficient certainty to specify the mutated gene as the likely cause before testing. CONCLUSIONS: Our data demonstrate the considerable utility of a gene panel approach in the diagnosis of patients with early-onset epilepsy and severe developmental delay disorders., They provide further insights into the phenotypic spectrum and genotype-phenotype correlations for a number of the causative genes and emphasise the value of exon-level copy number testing in their analysis
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