1,758 research outputs found
An Empirical Investigation of Pull Requests in Partially Distributed BizDevOps Teams
In globally distributed projects, virtual teams are often partially
dispersed. One common setup occurs when several members from one company work
with a large outsourcing vendor based in another country. Further, the
introduction of the popular BizDevOps concept has increased the necessity to
cooperate across departments and reduce the age-old disconnection between the
business strategy and technical development. Establishing a good collaboration
in partially distributed BizDevOps teams requires extensive collaboration and
communication techniques. Nowadays, a common approach is to rely on
collaboration through pull requests and frequent communication on Slack. To
investigate barriers for pull requests in distributed teams, we examined an
organization located in Scandinavia where cross-functional BizDevOps teams
collaborated with off-site team members in India. Data were collected by
conducting 14 interviews, observing 23 entire days with the team, and observing
37 meetings. We found that the pull-request approach worked very well locally
but not across sites. We found barriers such as domain complexity, different
agile processes (timeboxed vs. flow-based development), and employee turnover.
Using an intellectual capital lens on our findings, we discuss barriers and
positive and negative effects on the success of the pull-request approach
Renal ammonium excretion after an acute acid load: Blunted response in uric acid stone formers but not in patients with type 2 diabetes
Idiopathic uric acid nephrolithiasis is characterized by elevated urinary net acid excretion and insufficient buffering by ammonium, resulting in excessively acidic urine and titration of the relatively soluble urate anion to insoluble uric acid. Patients with type 2 diabetes have similar changes in urinary pH, net acid excretion, and ammonium in 24-h urine collections at baseline, even after controlling for dietary factors, and are at increased risk for uric acid nephrolithiasis. However, not all patients with type 2 diabetes develop kidney stones, suggesting that uric acid stone formers may have additional urinary defects, perhaps not apparent at baseline. We performed a metabolic study of 14 patients with idiopathic uric acid nephrolithiasis, 13 patients with type 2 diabetes, and 8 healthy control subjects of similar body mass index. After equilibration on a fixed diet for 5 days, subjects were given a single oral acid load (50 meq ammonium chloride), and urine was collected hourly for 4 h. Uric acid stone formers had a lower ammonium excretory response to acute acid loading compared with diabetic and nondiabetic nonstone formers, suggesting that an ammonium excretory defect unique to uric acid stone formers was unmasked by the acid challenge. The Zucker diabetic fatty rat also did not show impaired urinary ammonium excretion in response to acute acid challenge. A blunted renal ammonium excretory response to dietary acid loads may contribute to the pathogenesis of idiopathic uric acid nephrolithiasis. © 2013 the American Physiological Society
Civilising the natives? Liberal studies in further education revisited
This paper uses Basil Bernstein’s work on pedagogic discourses to examine a largely neglected facet of the history of vocational education – the liberal studies movement in English further education (FE) colleges. Initially, the paper discusses some of the competing conceptions of education, work and society which underpinned the rise and fall of the liberal studies movement – if indeed it can be described as such. It then draws on data from interviews with former liberal and general studies (LS/GS) lecturers to focus on the ways in which different variants of liberal studies were, over time, implicated in inculcating certain forms of knowledge in vocational learners. Whilst it is acknowledged that LS/GS always represented contested territory and that it was highly variable both in terms of content and quality, the paper argues that, at least and under certain circumstances, liberal studies provided young working-class people with the opportunity to locate their experiences of vocational learning within a critical framework which is largely absent from FE today. This, it is argued, can be conceptualised as an engagement with what Bernstein described as ‘powerful knowledge’
Noise Effects on the Complex Patterns of Abnormal Heartbeats
Patients at high risk for sudden death often exhibit complex heart rhythms in
which abnormal heartbeats are interspersed with normal heartbeats. We analyze
such a complex rhythm in a single patient over a 12-hour period and show that
the rhythm can be described by a theoretical model consisting of two
interacting oscillators with stochastic elements. By varying the magnitude of
the noise, we show that for an intermediate level of noise, the model gives
best agreement with key statistical features of the dynamics.Comment: 4 pages, 4 figures, RevTe
Dynamics of lattice spins as a model of arrhythmia
We consider evolution of initial disturbances in spatially extended systems
with autonomous rhythmic activity, such as the heart. We consider the case when
the activity is stable with respect to very smooth (changing little across the
medium) disturbances and construct lattice models for description of
not-so-smooth disturbances, in particular, topological defects; these models
are modifications of the diffusive XY model. We find that when the activity on
each lattice site is very rigid in maintaining its form, the topological
defects - vortices or spirals - nucleate a transition to a disordered,
turbulent state.Comment: 17 pages, revtex, 3 figure
A Hydrophobic Gate in an Ion Channel: The Closed State of the Nicotinic Acetylcholine Receptor
The nicotinic acetylcholine receptor (nAChR) is the prototypic member of the
`Cys-loop' superfamily of ligand-gated ion channels which mediate synaptic
neurotransmission, and whose other members include receptors for glycine,
gamma-aminobutyric acid, and serotonin. Cryo-electron microscopy has yielded a
three dimensional structure of the nAChR in its closed state. However, the
exact nature and location of the channel gate remains uncertain. Although the
transmembrane pore is constricted close to its center, it is not completely
occluded. Rather, the pore has a central hydrophobic zone of radius about 3 A.
Model calculations suggest that such a constriction may form a hydrophobic
gate, preventing movement of ions through a channel. We present a detailed and
quantitative simulation study of the hydrophobic gating model of the nicotinic
receptor, in order to fully evaluate this hypothesis. We demonstrate that the
hydrophobic constriction of the nAChR pore indeed forms a closed gate.
Potential of mean force (PMF) calculations reveal that the constriction
presents a barrier of height ca. 10 kT to the permeation of sodium ions,
placing an upper bound on the closed channel conductance of 0.3 pS. Thus, a 3 A
radius hydrophobic pore can form a functional barrier to the permeation of a 1
A radius Na+ ion. Using a united atom force field for the protein instead of an
all atom one retains the qualitative features but results in differing
conductances, showing that the PMF is sensitive to the detailed molecular
interactions.Comment: Accepted by Physical Biology; includes a supplement and a
supplementary mpeg movie can be found at
http://sbcb.bioch.ox.ac.uk/oliver/download/Movies/watergate.mp
A Systematic Review of Music Therapy Practice and Outcomes with Acute Adult Psychiatric In-Patients
PMCID: PMC3732280This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Systemic, Mucosal, and Heterotypic Immune Induction in Mice Inoculated with Venezuelan Equine Encephalitis Replicons Expressing Norwalk Virus-Like Particles
Norwalk-like viruses (NLVs) are a diverse group of single-stranded, nonenveloped, positive-polarity RNA viruses and are the leading cause of epidemic acute gastroenteritis in the United States. In this study, the major capsid gene of Norwalk virus, the prototype NLV, has been cloned and expressed in mammalian cells using a Venezuelan equine encephalitis (VEE) replicon expression system. Upon infection of baby hamster kidney (BHK) cells with VEE replicon particles (VRPs), the Norwalk virus capsid proteins self-assemble to generate high titers of Norwalk virus-like particles (VLPs) that are morphologically and antigenically analogous to wild-type Norwalk virus. Mice inoculated subcutaneously with VRPs expressing the Norwalk virus capsid protein (VRP-NV1) developed systemic and mucosal immune responses to Norwalk VLPs, as well as heterotypic antibody responses to the major capsid protein from another genogroup I NLV strain (NCFL) isolated from a recent outbreak. A second Norwalk virus capsid clone (NV2) containing three amino acid codon mutations from the NV1 clone was also expressed using VEE replicons (VRP-NV2), but upon infection of BHK cells failed to confer VLP self-assembly. Mice inoculated with VRP-NV2 elicited reduced systemic and mucosal immune responses to Norwalk VLPs, demonstrating the importance and potential utility of endogenous VLP presentation for maximum immune induction. Inoculation with either VRP-NV1 or VRP-NV2 resulted in serum antibody responses far superior to the induction in mice dosed orally with VLPs that were prepared using the VEE-NV1 replicon construct, a regimen similar to current models for NLV vaccination. Expression of NLV VLPs in mammalian cells offers a powerful approach for the design of novel NLV vaccines, either alone or in combination with current vaccination models
Growing Correlation Length on Cooling Below the Onset of Caging in a Simulated Glass-Forming Liquid
We present a calculation of a fourth-order, time-dependent density
correlation function that measures higher-order spatiotemporall correlations of
the density of a liquid. From molecular dynamics simulations of a glass-forming
Lennard-Jones liquid, we find that the characteristic length scale of this
function has a maximum as a function of time which increases steadily beyond
the characteristic length of the static pair correlation function in the
temperature range approaching the mode coupling temperature from above
Merit, Tenure, and Bureaucratic Behavior: Evidence From a Conjoint Experiment in the Dominican Republic
Bureaucratic behavior in developing countries remains poorly understood. Why do some
public servants – yet not others – work hard to deliver public services, misuse state
resources, and/or participate in electoral mobilization? A classic answer comes from Weber:
bureaucratic structures shift behavior towards integrity, neutrality, and commitment to
public service. Our paper conducts the first survey experimental test of the effects of
bureaucratic structures. It does so through a conjoint experiment with public servants in the
Dominican Republic. Looking at merit examinations and job stability, we find that Weber
was right – but only partially. Recruitment by examination curbs corruption and political
services by bureaucrats, while enhancing work motivation. Job stability, by contrast, only
decreases political services: tenured bureaucrats are less likely to participate in electoral
mobilization. Examinations thus enhance the quality of bureaucracy (motivation and lower
corruption) and democracy (electoral competition); job stability only enhances the quality
of democracy
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