1,937 research outputs found
The ducky^{2J} Mutation in Cacna2d2 Results in Reduced Spontaneous Purkinje Cell Activity and Altered Gene Expression
The mouse mutant ducky and its allele ducky^{2J} represent a model for absence epilepsy characterized by spike-wave seizures and cerebellar ataxia. These mice have mutations in Cacna2d2, which encodes the α₂δ-2 calcium channel subunit. Of relevance to the ataxic phenotype, α₂δ-2 mRNA is strongly expressed in cerebellar Purkinje cells (PCs). The Cacna2d2du2J mutation results in a 2 bp deletion in the coding region and a complete loss of α₂δ-2 protein. Here we show that du^{2J}/du^{2J} mice have a 30% reduction in somatic calcium current and a marked fall in the spontaneous PC firing rate at 22°C, accompanied by a decrease in firing regularity, which is not affected by blocking synaptic input to PCs. At 34°C, du^{2J}/du^{2J} PCs show no spontaneous intrinsic activity. DU^{2J}/du^{2J} mice also have alterations in the cerebellar expression of several genes related to PC function. At postnatal day 21, there is an elevation of tyrosine hydroxylase mRNA and a reduction in tenascin-C gene expression. Although du^{2J}/+ mice have a marked reduction in α₂δ-2 protein, they show no fall in PC somatic calcium currents or increase in cerebellar tryrosine hydroxylase gene expression. However, du^{2J}/+ PCs do exhibit a significant reduction in firing rate, correlating with the reduction in α₂δ-2. A hypothesis for future study is that effects on gene expression occur as a result of a reduction in somatic calcium currents, whereas effects on PC firing occur as a long-term result of loss of α₂δ-2 and/or a reduction in calcium currents and calcium-dependent processes in regions other than the soma
Microstructural damage of the posterior corpus callosum contributes to the clinical severity of neglect
One theory to account for neglect symptoms in patients with right focal damage invokes a release of inhibition of the right parietal cortex over the left parieto-frontal circuits, by disconnection mechanism. This theory is supported by transcranial magnetic stimulation studies showing the existence of asymmetric inhibitory interactions between the left and right posterior parietal cortex, with a right hemispheric advantage. These inhibitory mechanisms are mediated by direct transcallosal projections located in the posterior portions of the corpus callosum. The current study, using diffusion imaging and tract-based spatial statistics (TBSS), aims at assessing, in a data-driven fashion, the contribution of structural disconnection between hemispheres in determining the presence and severity of neglect. Eleven patients with right acute stroke and 11 healthy matched controls underwent MRI at 3T, including diffusion imaging, and T1-weighted volumes. TBSS was modified to account for the presence of the lesion and used to assess the presence and extension of changes in diffusion indices of microscopic white matter integrity in the left hemisphere of patients compared to controls, and to investigate, by correlation analysis, whether this damage might account for the presence and severity of patients' neglect, as assessed by the Behavioural Inattention Test (BIT). None of the patients had any macroscopic abnormality in the left hemisphere; however, 3 cases were discarded due to image artefacts in the MRI data. Conversely, TBSS analysis revealed widespread changes in diffusion indices in most of their left hemisphere tracts, with a predominant involvement of the corpus callosum and its projections on the parietal white matter. A region of association between patients' scores at BIT and brain FA values was found in the posterior part of the corpus callosum. This study strongly supports the hypothesis of a major role of structural disconnection between the right and left parietal cortex in determining 'neglect'
Nonlinear response of the vacuum Rabi resonance
On the level of single atoms and photons, the coupling between atoms and the
electromagnetic field is typically very weak. By employing a cavity to confine
the field, the strength of this interaction can be increased many orders of
magnitude to a point where it dominates over any dissipative process. This
strong-coupling regime of cavity quantum electrodynamics has been reached for
real atoms in optical cavities, and for artificial atoms in circuit QED and
quantum-dot systems. A signature of strong coupling is the splitting of the
cavity transmission peak into a pair of resolvable peaks when a single resonant
atom is placed inside the cavity - an effect known as vacuum Rabi splitting.
The circuit QED architecture is ideally suited for going beyond this linear
response effect. Here, we show that increasing the drive power results in two
unique nonlinear features in the transmitted heterodyne signal: the
supersplitting of each vacuum Rabi peak into a doublet, and the appearance of
additional peaks with the characteristic sqrt(n) spacing of the Jaynes-Cummings
ladder. These constitute direct evidence for the coupling between the quantized
microwave field and the anharmonic spectrum of a superconducting qubit acting
as an artificial atom.Comment: 6 pages, 4 figures. Supplementary Material and Supplementary Movies
are available at http://www.eng.yale.edu/rslab/publications.htm
Older adults experiences of rehabilitation in acute health care
Rehabilitation is a key component of nursing and allied healthcare professionals’ roles in most health and social care settings. This paper reports on stage 2 of an action research project to ascertain older adult's experience of rehabilitation. Twenty postdischarge interviews were conducted and the interview transcripts were analysed using thematic content analysis. All older adults discharged from an acute older acute rehabilitation ward to their own homes in the community were eligible to participate. The only exclusion criterion was older adults who were thought to be unable to give consent to participate by the nurse in charge and the researcher. Whilst 92 older adults were eligible to participate in this research study, only 20 were interviewed. The findings from this study suggest that older adults valued communication with health professionals but were aware of their time constraints that hindered communication. This study suggests that both nurses and allied health professionals are not actively providing rehabilitative services to promote health and well-being, which contradicts the focus of active ageing. Furthermore, there was evidence of unmet needs on discharge, and older adults unable to recall the professions that were involved in their interventions and the rationale for therapy input. It is suggested that further research is needed to explore the effectiveness of allied health rehabilitation in the acute setting. This study highlights the need for further research into older adults’ perceptions of the rehabilitation process in the acute setting
Roy-Steiner equations for pion-nucleon scattering
Starting from hyperbolic dispersion relations, we derive a closed system of
Roy-Steiner equations for pion-nucleon scattering that respects analyticity,
unitarity, and crossing symmetry. We work out analytically all kernel functions
and unitarity relations required for the lowest partial waves. In order to
suppress the dependence on the high-energy regime we also consider once- and
twice-subtracted versions of the equations, where we identify the subtraction
constants with subthreshold parameters. Assuming Mandelstam analyticity we
determine the maximal range of validity of these equations. As a first step
towards the solution of the full system we cast the equations for the
partial waves into the form of a Muskhelishvili-Omn\`es
problem with finite matching point, which we solve numerically in the
single-channel approximation. We investigate in detail the role of individual
contributions to our solutions and discuss some consequences for the spectral
functions of the nucleon electromagnetic form factors.Comment: 106 pages, 18 figures; version published in JHE
Are people with chronic diseases interested in using telehealth?: a cross-sectional postal survey
Background
There is growing interest in telehealth—the use of technology to support the remote delivery of health care and promote self-management—as a potential alternative to face-to-face care for patients with chronic diseases. However, little is known about what precipitates interest in the use of telehealth among these patients.
Objective
This survey forms part of a research program to develop and evaluate a telehealth intervention for patients with two exemplar chronic diseases: depression and raised cardiovascular disease (CVD) risk. The survey was designed to explore the key factors that influence interest in using telehealth in these patient groups.
Methods
Thirty-four general practices were recruited from two different regions within England. Practice records were searched for patients with (1) depression (aged 18+ years) or (2) 10-year risk of CVD ≥20% and at least one modifiable risk factor (aged 40-74 years). Within each general practice, 54 patients in each chronic disease group were randomly selected to receive a postal questionnaire. Questions assessed five key constructs: sociodemographics, health needs, difficulties accessing health care, technology-related factors (availability, confidence using technology, perceived benefits and drawbacks of telehealth), and satisfaction with prior use of telehealth. Respondents also rated their interest in using different technologies for telehealth (phone, email and Internet, or social media). Relationships between the key constructs and interest in using the three mediums of telehealth were examined using multivariable regression models.
Results
Of the 3329 patients who were sent a study questionnaire, 44.40% completed it (872/1740, 50.11% CVD risk; 606/1589, 38.14% depression). Overall, there was moderate interest in using phone-based (854/1423, 60.01%) and email/Internet-based (816/1425, 57.26%) telehealth, but very little interest in social media (243/1430, 16.99%). After adjusting for health needs, access difficulties, technology-related factors, and prior use of telehealth, interest in telehealth had largely no association with sociodemographic variables. For both patient groups and for each of the three technology mediums, the most important constructs related to interest in telehealth were having the confidence to use the associated technology, as well as perceiving greater advantages and fewer disadvantages from using telehealth. To illustrate, greater confidence using phone technologies (b=.16, 95% CI 0.002-0.33), while also perceiving more benefits (b=.31, 95% CI 0.21-0.40) and fewer drawbacks (b=-.23, 95% CI -0.28 to -0.17) to using telehealth were associated with more interest in using phone-based telehealth technologies for patients with depression.
Conclusions
There is widespread interest in using phone-based and email/Internet-based telehealth among patients with chronic diseases, regardless of their health status, access difficulties, age, or many other sociodemographic factors. This interest could be increased by helping patients gain confidence using technologies and through highlighting benefits and addressing concerns about telehealth. While the same pattern exists for social media telehealth, interest in using these technologies is minimal
A Continental-Wide Perspective: The Genepool of Nuclear Encoded Ribosomal DNA and Single-Copy Gene Sequences in North American Boechera (Brassicaceae)
74 of the currently accepted 111 taxa of the North American genus Boechera (Brassicaceae) were subject to pyhlogenetic reconstruction and network analysis. The dataset comprised 911 accessions for which ITS sequences were analyzed. Phylogenetic analyses yielded largely unresolved trees. Together with the network analysis confirming this result this can be interpreted as an indication for multiple, independent, and rapid diversification events. Network analyses were superimposed with datasets describing i) geographical distribution, ii) taxonomy, iii) reproductive mode, and iv) distribution history based on phylogeographic evidence. Our results provide first direct evidence for enormous reticulate evolution in the entire genus and give further insights into the evolutionary history of this complex genus on a continental scale. In addition two novel single-copy gene markers, orthologues of the Arabidopsis thaliana genes At2g25920 and At3g18900, were analyzed for subsets of taxa and confirmed the findings obtained through the ITS data
A Systematic Review of Online Sex Addiction and Clinical Treatments Using CONSORT Evaluation
Researchers have suggested that the advances of the Internet over the past two decades have gradually eliminated traditional offline methods of obtaining sexual material. Additionally, research on cybersex and/or online sex addictions has increased alongside the development of online technology. The present study extended the findings from Griffiths’ (2012) systematic empirical review of online sex addiction by additionally investigating empirical studies that implemented and/or documented clinical treatments for online sex addiction in adults. A total of nine studies were identified and then each underwent a CONSORT evaluation. The main findings of the present review provide some evidence to suggest that some treatments (both psychological and/or pharmacological) provide positive outcomes among those experiencing difficulties with online sex addiction. Similar to Griffiths’ original review, this study recommends that further research is warranted to establish the efficacy of empirically driven treatments for online sex addiction
Metal artifact suppression at the hip: diagnostic performance at 3.0 T versus 1.5 Tesla
PurposeThis work aimed to compare the diagnostic performance of a metal artifact suppression sequence (MAVRIC-SL) for imaging of hip arthroplasties (HA) at 1.5 and 3 Tesla (T) field strength.MethodsEighteen patients (10 females; aged 27-74) with HA were examined at 3.0 and 1.5 T within 3 weeks. The sequence protocol included 3D-MAVRIC-SL PD (coronal), 3D-MAVRIC-SL STIR (axial), FSE T1, FSE PD and STIR sequences. Anatomical structures and pathological findings were assessed independently by two radiologists. Artifact extent and technical quality (image quality, fat saturation and geometric distortion) were also evaluated. Findings at 1.5 and 3.0 T were compared using a Wilcoxon signed rank test.ResultsWhile image quality was better at 1.5 T, visualization of anatomic structures and clinical abnormalities was not significantly different using the two field strengths (p > 0.05). Fat suppression and amount of artifacts were significantly better at 1.5 T (p < 0.01). Inter- and intra-reader agreement for different anatomic details, image quality and visualization of abnormalities ranged from k = 0.62 to k = 1.00.ConclusionMAVRIC-SL at 1.5 T had a comparable diagnostic performance when compared MAVRIC-SL at 3.0 T; however, the higher field strength was associated with larger artifacts, limited image quality and worse fat saturation
The epidemiology of pertussis in Germany: past and present
<p>Abstract</p> <p>Background</p> <p>Current and past pertussis epidemiology in the two parts of Germany is compared in the context of different histories of vaccination recommendations and coverage to better understand patterns of disease transmission.</p> <p>Methods</p> <p>Available regional pertussis surveillance and vaccination coverage data, supplemented by a literature search for published surveys as well as official national hospital and mortality statistics, were analyzed in the context of respective vaccination recommendations from 1964 onwards.</p> <p>Results</p> <p>Routine childhood pertussis vaccination was recommended in the German Democratic Republic (GDR) from 1964 and in former West German states (FWG) from 1969, but withdrawn from 1974–1991 in FWG. Pertussis incidence declined to <1 case/100.000 inhabitants in GDR prior to reunification in 1991, while in FWG, where pertussis was not notifiable after 1961, incidence was estimated at 160–180 cases/100.000 inhabitants in the 1970s-1980s. Despite recommendations for universal childhood immunization in 1991, vaccination coverage decreased in former East German States (FEG) and increased only slowly in FWG. After introduction of acellular pertussis vaccines in 1995, vaccination coverage increased markedly among younger children, but remains low in adolescents, especially in FWG, despite introduction of a booster vaccination for 9–17 year olds in 2000. Reported pertussis incidence increased in FEG to 39.3 cases/100.000 inhabitants in 2007, with the proportion of adults increasing from 20% in 1995 to 68% in 2007. From 2004–2007, incidence was highest among 5–14 year-old children, with a high proportion fully vaccinated according to official recommendations, which did not include a preschool booster until 2006. Hospital discharge statistics revealed a ~2-fold higher pertussis morbidity among infants in FWG than FEG.</p> <p>Conclusion</p> <p>The shift in pertussis morbidity to older age groups observed in FEG is similar to reports from other countries with longstanding vaccination programs and suggests that additional booster vaccination may be necessary beyond adolescence. The high proportion of fully vaccinated cases in older children in FEG suggests waning immunity 5–10 years after primary immunisation in infancy. The higher incidence of pertussis hospitalisations in infants suggests a stronger force of infection in FWG than FEG. Nationwide pertussis reporting is required for better evaluation of transmission patterns and vaccination policy in both parts of Germany.</p
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