1,250 research outputs found
Infrared aircraft measurements of stratospheric composition over Antarctica during September 1987
The JPL Mark IV interferometer recorded high resolution, infared solar spectra from the NASA DC-8 aircraft during flights over Antarctica in September 1987. The atmospheric absorption features in these spectra were analyzed to determine the overburdens of O3, NO, NO2, HNO3, ClONO2, HCl, HF, CH4, N2O, CO, H2O and CFC-12. The spectra were obtained at latitudes which ranged between 64 degrees S and 86 degrees S, allowing the composition in the interior of the polar vortex to be compared with that at the edge. The latitude dependence observed for NO, HO2, HNO3, ClONO2, HCl and HF are summerized. The values at 30 deg S were observed on the ferry flight from New Zealand to Hawaii. The dashed lines connecting the two were interpolated across the region for which there are no measurements. The chemically perturbed region is seen to consist of a collar of high HNO3 and ClONO2 surrounding a core in which the overburdens of these and of HCl and NO2 are very low. Clear increases in the overburdens of HF and HNO3 were observed during the course of September in the vortex core. HCl and NO2 exhibited smaller, less significant increases. The overburdens of the tropospheric source gases, N2O, CH4, CF2Cl2, and H2O were observed to much smaller over Antarctica than at mid-latitudes. This, together with the fact that HF over Antarctica was more that double its mid-latitude value, suggests that downwelling has occurred
Vapour layer formation by electrical discharges through electrically conducting liquids-modelling and experiment
Wakefield-Induced Ionization injection in beam-driven plasma accelerators
We present a detailed analysis of the features and capabilities of
Wakefield-Induced Ionization (WII) injection in the blowout regime of beam
driven plasma accelerators. This mechanism exploits the electric wakefields to
ionize electrons from a dopant gas and trap them in a well-defined region of
the accelerating and focusing wake phase, leading to the formation of
high-quality witness-bunches [Martinez de la Ossa et al., Phys. Rev. Lett. 111,
245003 (2013)]. The electron-beam drivers must feature high-peak currents
() and a duration comparable to the plasma
wavelength to excite plasma waves in the blowout regime and enable WII
injection. In this regime, the disparity of the magnitude of the electric field
in the driver region and the electric field in the rear of the ion cavity
allows for the selective ionization and subsequent trapping from a narrow phase
interval. The witness bunches generated in this manner feature a short duration
and small values of the normalized transverse emittance (). In addition, we show that the amount of injected
charge can be adjusted by tuning the concentration of the dopant gas species,
which allows for controlled beam loading and leads to a reduction of the total
energy spread of the witness beams. Electron bunches, produced in this way,
fulfil the requirements to drive blowout regime plasma wakes at a higher
density and to trigger WII injection in a second stage. This suggests a
promising new concept of self-similar staging of WII injection in steps with
increasing plasma density, giving rise to the potential of producing electron
beams with unprecedented energy and brilliance from plasma-wakefield
accelerators
Impurity intrusion in radio-frequency micro-plasma jets operated in ambient air
Space and time resolved concentrations of helium metastable atoms in an
atmospheric pressure radio-frequency micro-plasma jet were measured using
tunable diode laser absorption spectroscopy. Spatial profiles as well as
lifetime measurements show significant influences of air entering the discharge
from the front nozzle and of impurities originating from the gas supply system.
Quenching of metastables was used to deduce quantitative concentrations of
intruding impurities. The impurity profile along the jet axis was determined
from optical emission spectroscopy as well as their dependance on the feed gas
flow through the jet.Comment: Journal of Physics D: Applied Physics (accepted), 6 page
Imaging the Electrocyte of Torpedo Marmorata by Scanning Force Microscopy
Scanning force microscopy (SFM) and scanning electron microscopy (SEM) were used to examine the tissue structure of the electric organ of Torpedo marmorata in air and in liquid after applying fracturing and cryosectioning techniques and chemical fixation. The electric organ is organized in columns of stacked electrocytes, arranged in a honeycomb pattern. The columns were cut along a plane normal to the cell stack and thin sections were transferred to polylysine coated glass coverslips. The polarity of the electrocytes was made apparent by immunofluorescence microscopy directed to different domains of the acetylcholine receptor (AChR), thus revealing the innervated face of the cell. SFM and SEM both showed cell surfaces to be overlaid by a network of collagen fibers by their characteristic banding pattern with about 64 nm periodicity and about 2.5 nm corrugation amplitude. In liquid, significantly lower structural resolution was achieved by SFM, probably due to sample elasticity
Bovine Blood Constituents as Fat Replacers in Ham Pâté
Some tests were carried out in this work with the aim of evaluating a partial replacement of fat in the raw batter of ham pâté by using bovine blood constituents, such as globin (GL), plasma (PL) or 1:1 globin and plasma (GP). Plasma was separated from red cells by blood centrifugation, and globin was extracted by the carboxymethylcellulose method. The salt-soluble protein content (SSP) and the binding properties including water holding capacity (WHC) and raw batter stability (RBS) were estimated. The results indicated that among the 3 treatments studied, the use of globin showed to be a little more advantageous for the quality of the raw batter of ham pâté, since its incorporation as fat replacer led to an increase in RBS but no change of SSP was observed
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Investigating the enabling factors influencing occupational therapists’ adoption of assisted living technology
Introduction
Research into technology adoption has focused on older adults’ motivations, with less exploration of the perspective of healthcare providers, including occupational therapists, who are often described as the gatekeepers to assisted living technology.
Method
This qualitative study utilized semi-structured interviews and focus groups with 20 occupational therapists in England and Scotland. The goal was to identify those enabling factors necessary for occupational therapists to adopt assisted living technology.
Results
Five themes emerged regarding the enablers needed to support the adoption of assisted living technology by occupational therapists, including: (1) a positive client–therapist relationship; (2) affordability; (3) time; (4) increased awareness, education, and training; and (5) usability features of the assisted living technology.
Conclusion
With an aging population and the increasing role that technology is playing globally in older adults’ lives, it has never been more important for occupational therapists to harness the potential of new, developing, and existing technologies to support people to live and age as well as possible. To accomplish this, however, requires that occupational therapists are equipped with the time, training, and education necessary to offer their clients assisted living technologies that are client-centered, usable, and affordabl
The epidemiology of infections with Giardia species and genotypes in well cared for dogs and cats in Germany
Background
Giardia is now considered the most common enteric parasite in well cared for dogs and cats in developed countries. The ecology, epidemiology and clinical impact of infections with this parasite in such animals is still not fully understood due to variable results across different studies.
Methods
Faecal samples were collected between 2009 and 2012 from privately owned cats and dogs in Germany presented to local veterinarians for a variety of reasons. Giardia positive samples were identified by microscopy and coproantigen methods. Total faecal DNA was extracted from Giardia positive samples and multilocus genotyping methods (18S rDNA, β-giardin, GDH) were applied. Relationships between host age, sex, and breed, season of presentation and the different species of Giardia detected were assessed.
Results
A total of 60 cat and 130 dog samples were identified as Giardia positive. Potentially zoonotic Giardia was identified in both animal species. Cats had a similarly high rate of infection with the G. duodenalis and G. cati. Cats less than 1 year were more likely to have G. duodenalis than cats older than 1 year. Pure breed cats demonstrated a greater proportion of zoonotic species than mixed breed cats. In samples from dogs, G. canis (C and D genotypes) were identified most commonly. Male dogs were more likely to have G. canis (genotype D) than female dogs. The 18S rDNA PCR protocol was the most successful followed by the β-giardin and GDH (amplifying from 92%, 42% and 13% of samples respectively).
Conclusions
The potentially zoonotic species G. duodenalis and G. enterica were found in cat and dog samples, with G. duodenalis found in greater numbers; however, this may be due to the detection techniques utilised. Cats appeared to show a relationship between G. duodenalis and G. cati with age and breed, which may be explained by different housing habitats for pure and mixed breed cats. The different success rates for the three loci utilised highlights the usefulness of the 18S locus as a screening tool, as well as the importance of using multiple loci for genotyping to fully determine the level of multiple infection of Giardia present
Interaction of suppressor of cytokine signalling 3 with cavin-1 links SOCS3 function and cavin-1 stability
YesEffective suppression of JAK–STAT signalling by the inducible inhibitor “suppressor of
cytokine signalling 3” (SOCS3) is essential for limiting signalling from cytokine receptors.
Here we show that cavin-1, a component of caveolae, is a functionally significant SOCS3-
interacting protein. Biochemical and confocal imaging demonstrate that SOCS3 localisation to
the plasma membrane requires cavin-1. SOCS3 is also critical for cavin-1 stabilisation, such
that deletion of SOCS3 reduces the expression of cavin-1 and caveolin-1 proteins, thereby
reducing caveola abundance in endothelial cells. Moreover, the interaction of cavin-1 and
SOCS3 is essential for SOCS3 function, as loss of cavin-1 enhances cytokine-stimulated
STAT3 phosphorylation and abolishes SOCS3-dependent inhibition of IL-6 signalling by cyclic
AMP. Together, these findings reveal a new functionally important mechanism linking
SOCS3-mediated inhibition of cytokine signalling to localisation at the plasma membrane via
interaction with and stabilisation of cavin-1.This work was supported by project grants to T.M.P. from the Chief Scientist Office (ETM/226), British Heart Foundation (PG12/1/ 29276, PG 14/32/30812), and a National Health Service Greater Glasgow and Clyde Research Endowment Fund (2011REFCH08). P.F.P. was supported by the National Institutes of Health grant DK097708. J.J.L.W. was supported by a doctoral training studentship from the Biotechnology and Biological Sciences Research Council Doctoral Training Programme in Biochemistry and Molecular Biology at the University of Glasgow (BB/F016735/1). N.A. was supported by a Saudi Government PhD Scholarship. This work was also supported in part by equipment grants to T.M.P. from Diabetes UK (BDA 11/0004309) and Alzheimer’s Research UK (ARUK-EG2016A-3)
Mapping Lesion-Related Epilepsy to a Human Brain Network
Importance: It remains unclear why lesions in some locations cause epilepsy while others do not. Identifying the brain regions or networks associated with epilepsy by mapping these lesions could inform prognosis and guide interventions.
Objective: To assess whether lesion locations associated with epilepsy map to specific brain regions and networks.
Design, setting, and participants: This case-control study used lesion location and lesion network mapping to identify the brain regions and networks associated with epilepsy in a discovery data set of patients with poststroke epilepsy and control patients with stroke. Patients with stroke lesions and epilepsy (n = 76) or no epilepsy (n = 625) were included. Generalizability to other lesion types was assessed using 4 independent cohorts as validation data sets. The total numbers of patients across all datasets (both discovery and validation datasets) were 347 with epilepsy and 1126 without. Therapeutic relevance was assessed using deep brain stimulation sites that improve seizure control. Data were analyzed from September 2018 through December 2022. All shared patient data were analyzed and included; no patients were excluded.
Main outcomes and measures: Epilepsy or no epilepsy.
Results: Lesion locations from 76 patients with poststroke epilepsy (39 [51%] male; mean [SD] age, 61.0 [14.6] years; mean [SD] follow-up, 6.7 [2.0] years) and 625 control patients with stroke (366 [59%] male; mean [SD] age, 62.0 [14.1] years; follow-up range, 3-12 months) were included in the discovery data set. Lesions associated with epilepsy occurred in multiple heterogenous locations spanning different lobes and vascular territories. However, these same lesion locations were part of a specific brain network defined by functional connectivity to the basal ganglia and cerebellum. Findings were validated in 4 independent cohorts including 772 patients with brain lesions (271 [35%] with epilepsy; 515 [67%] male; median [IQR] age, 60 [50-70] years; follow-up range, 3-35 years). Lesion connectivity to this brain network was associated with increased risk of epilepsy after stroke (odds ratio [OR], 2.82; 95% CI, 2.02-4.10; P \u3c .001) and across different lesion types (OR, 2.85; 95% CI, 2.23-3.69; P \u3c .001). Deep brain stimulation site connectivity to this same network was associated with improved seizure control (r, 0.63; P \u3c .001) in 30 patients with drug-resistant epilepsy (21 [70%] male; median [IQR] age, 39 [32-46] years; median [IQR] follow-up, 24 [16-30] months).
Conclusions and relevance: The findings in this study indicate that lesion-related epilepsy mapped to a human brain network, which could help identify patients at risk of epilepsy after a brain lesion and guide brain stimulation therapies
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