3,712 research outputs found
Temporal profile and mechanisms of the prompt sympathoexcitation following coronary ligation in Wistar rats
Our aim was to assess the timing and mechanisms of the sympathoexcitation that occurs immediately after coronary ligation. We recorded thoracic sympathetic (tSNA) and phrenic activities, heart rate (HR) and perfusion pressure in Wistar rats subjected to either ligation of the left anterior descending coronary artery (LAD) or Sham operated in the working heart-brainstem preparation. Thirty minutes after LAD ligation, tSNA had increased (basal: 2.5±0.2 ”V, 30 min: 3.5±0.3 ”V), being even higher at 60 min (5.2±0.5 ”V, P<0.01); while no change was observed in Sham animals. HR increased significantly 45 min after LAD (P<0.01). Sixty minutes after LAD ligation, there was: (i) an augmented peripheral chemoreflex - greater sympathoexcitatory response (50, 45 and 27% of increase to 25, 50 and 75 ”L injections of NaCN 0.03%, respectively, when compared to Sham, P<0.01); (ii) an elevated pressor response (32±1 versus 23±1 mmHg in Sham, P<0.01) and a reduced baroreflex sympathetic gain (1.3±0.1 versus Sham 2.0±0.1%.mmHg-1, P<0.01) to phenylephrine injection; (iii) an elevated cardiac sympathetic tone (ÎHR after atenolol: -108±8 versus -82±7 bpm in Sham, P<0.05). In contrast, no changes were observed in cardiac vagal tone and bradycardic response to both baroreflex and chemoreflex between LAD and Sham groups. The immediate sympathoexcitatory response in LAD rats was dependent on an excitatory spinal sympathetic cardiocardiac reflex, whereas at 3 h an angiotensin II type 1 receptor mechanism was essential since Losartan curbed the response by 34% relative to LAD rats administered saline (P<0.05). A spinal reflex appears key to the immediate sympathoexcitatory response after coronary ligation. Therefore, the sympathoexcitatory response seems to be maintained by an angiotensinergic mechanism and concomitant augmentation of sympathoexcitatory reflexes
Exploring flexible working practices and the digital divide in a post-lockdown era
Purpose:
This paper explores flexible working practices (FWPs) and takes a critical view that argues a need to consider not only access to digital technological resources but also the vast array of factors that constrain oneâs ability to use technology for its intended benefits, as constituting the digital divide post-COVID-19 lockdown.
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Design/methodology/approach:
Using a critical evaluation of the extant literature, we engage in a conceptual undertaking to develop theoretical propositions that form the basis for future empirical undertakings. To theoretically ground the arguments raised, we deploy the ontological lens of actor-network theory to illuminate the socio-technical dimensions of the digital divide in light of FWPs.
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Findings:
Since the COVID-19 pandemic, the need to adopt socially distanced work practices has become a reality for many organisations. We find that the adoption of FWPs, enabled by digital technologies, simultaneously signals hidden inequalities. We also develop a conceptual framework which depicts user responses in different technology environments that can either be limiting or enabling for individualsâ work productivity.
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Originality/value:
With regards to the digital divide, attention has often focused on access to digital technologies, as the term âdigital divideâ portrays. The implication is that the array of factors and resources that individuals are heterogeneously networked to, which also constitute the digital divide, is often taken for granted. We take a different ontological view that brings to the fore other factors at play within an individualâs network of relations
Metal-Insulator transition in the Generalized Hubbard model
We present the exact ground-state wave function and energy of the generalized
Hubbard model, subjected to the condition that the number of double occupied
sites is conserved, for a wide, physically relevant range of parameters. For
one hole and one double occupied site the existence of the ferromagnetic
ground-state is proved which allow one to determine the critical value of the
on-site repulsion corresponding to the point of metal-insulator transition. For
the one dimensional model the exact solution for special values of the
parameters is obtained.Comment: 20 pages, LaTex. Mod.Phys.Lett.B 7 (1993) 1397; Journal of Physics:
Condensed Matter (to appear
The smallest Mealy automaton of intermediate growth
In this paper we study the smallest Mealy automaton of intermediate growth,
first considered by the last two authors. We describe the automatic
transformation monoid it defines, give a formula for the generating series for
its (ball volume) growth function, and give sharp asymptotics for its growth
function, namely [ F(n) \sim 2^{5/2} 3^{3/4} \pi^{-2} n^{1/4}
\exp{\pi\sqrt{n/6}} ] with the ratios of left- to right-hand side tending to 1
as
"Infiltrators" or refugees? An analysis of Israel's policy towards African asylum seekers
This article adopts a genealogical approach in examining Israeli immigration policy by focusing on the situation confronting African asylum seekers who have been forced back into Egypt, detained and deported but who have not had their asylum claims properly assessed. Based on immigration policies formulated at the time of Israeli independence, whose principle objective was to secure a Jewish majority state, we argue that Israelâs treatment of African asylum seekers as âinfiltratorsâ/economic migrants stems from an insistence on maintaining immigration as a sovereign issue formally isolated from other policy domains. Such an
approach is not only in violation of Israelâs commitment to the Refugee Convention, it directly contributes to policies which are ineffective and unduly harsh
Are advanced methods necessary to improve infant fNIRS data analysis? An assessment of baseline-corrected averaging, general linear model (GLM) and multivariate pattern analysis (MVPA) based approaches
In the last decade, fNIRS has provided a non-invasive method to investigate
neural activation in developmental populations. Despite its increasing use in
developmental cognitive neuroscience, there is little consistency or consensus
on how to pre-process and analyse infant fNIRS data. With this registered
report, we investigated the feasibility of applying more advanced statistical
analyses to infant fNIRS data and compared the most commonly used
baseline-corrected averaging, General Linear Model (GLM)-based univariate, and
Multivariate Pattern Analysis (MVPA) approaches, to show how the conclusions
one would draw based on these different analysis approaches converge or differ.
The different analysis methods were tested using a face inversion paradigm
where changes in brain activation in response to upright and inverted face
stimuli were measured in thirty 4-to-6-month-old infants. By including more
standard approaches together with recent machine learning techniques, we aim to
inform the fNIRS community on alternative ways to analyse infant fNIRS
datasets
Insomnia symptom prevalence in England: a comparison of cross-sectional self-reported data and primary care records in the UK Biobank
Objectives: We aimed to use a large dataset to compare self-reported and primary care measures of insomnia symptom prevalence in England and establish whether they identify participants with similar characteristics.
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Design: Cross-sectional study with linked electronic health records (EHRs).
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Setting: Primary care in England.
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Participants: 163â748 UK Biobank participants in England (aged 38â71 at baseline) with linked primary care EHRs.
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Outcome measures: We compared the percentage of those self-reporting âusuallyâ having insomnia symptoms at UK Biobank baseline assessment (2006â2010) to those with a Read code for insomnia symptoms in their primary care records prior to baseline. We stratified prevalence in both groups by sociodemographic, lifestyle, sleep and health characteristics.
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Results: We found that 29% of the sample self-reported having insomnia symptoms, while only 6% had a Read code for insomnia symptoms in their primary care records. Only 10% of self-reported cases had an insomnia symptom Read code, while 49% of primary care cases self-reported having insomnia symptoms. In both primary care and self-reported data, prevalence of insomnia symptom cases was highest in females, older participants and those with the lowest household incomes. However, while snorers and risk takers were more likely to be a primary care case, they were less likely to self-report insomnia symptoms than non-snorers and non-risk takers.
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Conclusions: Only a small proportion of individuals experiencing insomnia symptoms have an insomnia symptom Read code in their primary care record. However, primary care data do provide a clinically meaningful measure of insomnia prevalence. In addition, the sociodemographic characteristics of people attending primary care with insomnia were consistent with those with self-reported insomnia, thus primary care records are a valuable data source for studying risk factors for insomnia. Further studies should replicate our findings in other populations and examine ways to increase discussions about sleep health in primary care
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