95 research outputs found
Low platelet counts in pregnancy: an alarm signal for abruption!
Background: Thrombocytopenia, defined as a platelet count less than 150 million/mm3, affects 6% to 10% of all pregnant women and other than anemia is the most common hematologic disorder in pregnancy.Methods: We studied all patients with thrombocytopenia in pregnancy from June 2012 to May 2013. There were 86 patients recruited into the study. Pregnant women with preeclampsia and suspected connective tissue disorder were also screened for thrombocytopenia. All women with platelet count of <1.50,000/µl during the study period were included.Results: Patients were grouped in to mild thrombocytopenia (platelet 100,000-149,999/µl), moderate thrombocytopenia (platelet 50,000-99,999/µl) and severe thrombocytopenia (platelet <49,999/µl. Pregnancy specific cause of thrombocytopenia was in 63 (73.2%) women and non-pregnancy specific were in 23(26.7%) patients.Conclusions: Preeclampsia and HELLP syndrome is more common cause of thrombocytopenia in pregnancy. Abruption can occur in patients with severe thrombocytopenia. Though platelet count is not routinely done in pregnancy it is advisable to do so as it may help in detecting gestational thrombocytopenia or other immune related condition
Ruddy Shelduck Tadorna ferruginea home range and habitat use during the non-breeding season in Assam, India
India is an important non-breeding ground for migratory waterfowl in the Central Asian Flyway. Millions of birds visit wedands across the country, yet information on their distribution, abundance, and use of resources is rudimentary at best. Limited information suggests that populations of several species of migratory ducks are declining due to encroachment of wedand habitats largely by agriculture and industry. The development of conservation strategies is stymied by a lack of ecological information on these species. We conducted a preliminary assessment of the home range and habitat use of Ruddy Shelduck Tadornaferruginea in the northeast Indian state of Assam. Seven Ruddy Shelducks were fitted with solar-powered Global Positioning System (GPS) satellite transmitters, and were tracked on a daily basis during the winter of 2009-2010. Locations from all seven were used to describe habitat use, while locations from four were used to quantify their home range, as the other three had too few locations (<30) for home range estimation. A Brownian Bridge Movement Model (BBMM), used to estimate home ranges, found that the Ruddy Shelduck had an average core use area (i.e. the contour defining 50% of positions) of 40 km 2 (range = 22-87 km2) and an average home range (95% contour) of 610 km2 (range = 222-1,550 km2). Resource Selection Functions (RSF), used to describe habitat use, showed that the birds frequented riverine wetlands more than expected, occurred on grasslands and shrublands in proportion to their availability, and avoided woods and cropland habitats. The core use areas for three individuals (75%) were on the Brahmaputra River, indicating their preference for riverine habitats. Management and protection of riverine habitats and nearby grasslands may benefit conservation efforts for the Ruddy Shelduck and waterfowl species that share these habitats during the non-breeding seaso
A Study of Serum C-Reactive Protein (CRP) at Admission as a Predictor of Outcome in Febrile Children
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Blueswitch: Enabling provably consistent configuration of network switches
Previous research on consistent updates for distributed network
configurations has focused on solutions for centralized networkconfiguration
controllers. However, such work does not address
the complexity of modern switch datapaths. Modern commodity
switches expose opaque configuration mechanisms, with minimal
guarantees for datapath consistency and with unclear configuration
semantics. Furthermore, would-be solutions for distributed consistent
updates must take into account the configuration guarantees
provided by each individual switch – plus the compositional problems
of distributed control and multi-switch configurations that
considerably transcend the single-switch problems. In this paper,
we focus on the behavior of individual switches, and demonstrate
that even simple rule updates result in inconsistent packet switching
in multi-table datapaths. We demonstrate that consistent configuration
updates require guarantees of strong switch-level atomicity
from both hardware and software layers of switches – even in a
single switch. In short, the multiple-switch problems cannot be
reasonably approached until single-switch consistency can be resolved.
We present a hardware design that supports a transactional configuration
mechanism, and provides packet-consistent configuration:
all packets traversing the datapath will encounter either the
old configuration or the new one, and never an inconsistent mix of
the two. Unlike previous work, our design does not require modifications
to network packets. We precisely specify the hardwaresoftware
protocol for switch configuration; this enables us to prove
the correctness of the design, and to provide well-specified invariants
that the software driver must maintain for correctness. We
implement our prototype switch design using the NetFPGA-10G
hardware platform, and evaluate our prototype against commercial
off-the-shelf switches.This work was jointly supported by the Defense Advanced Research
Projects Agency (DARPA) and the Air Force Research Laboratory
(AFRL), under contract FA8750-11-C-0249. The views,
opinions, and/or findings contained in this article/presentation are
those of the author/ presenter and should not be interpreted as representing
the official views or policies, either expressed or implied,
of the Department of Defense or the U.S. Government. We also acknowledge
the support of the UK EPSRC for contributing to parts
of our work, through grant EP/H040536/1. Additional data related
to this publication is available at the http://www.cl.cam.ac.
uk/research/srg/netfpga/blueswitch/ data repository.This is the author accepted manuscript. The final version is available from IEEE via http://dx.doi.org/10.1109/ANCS.2015.711011
ISA semantics for ARMV8-A, RISC-V, and ChERI-MIPs
Architecture specifications notionally define the fundamental interface between hardware and software: the envelope of allowed behaviour for processor implementations, and the basic assumptions for software development and verification. But in practice, they are typically prose and pseudocode documents, not rigorous or executable artifacts, leaving software and verification on shaky ground.
In this paper, we present rigorous semantic models for the sequential behaviour of large parts of the mainstream ARMv8-A, RISC-V, and MIPS architectures, and the research CHERI-MIPS architecture, that are complete enough to boot operating systems, variously Linux, FreeBSD, or seL4. Our ARMv8-A models are automatically translated from authoritative ARM-internal definitions, and (in one variant) tested against the ARM Architecture Validation Suite.
We do this using a custom language for ISA semantics, Sail, with a lightweight dependent type system, that supports automatic generation of emulator code in C and OCaml, and automatic generation of proof-assistant definitions for Isabelle, HOL4, and (currently only for MIPS) Coq. We use the former for validation, and to assess specification coverage. To demonstrate the usability of the latter, we prove (in Isabelle) correctness of a purely functional characterisation of ARMv8-A address translation. We moreover integrate the RISC-V model into the RMEM tool for (user-mode) relaxed-memory concurrency exploration. We prove (on paper) the soundness of the core Sail type system.
We thereby take a big step towards making the architectural abstraction actually well-defined, establishing foundations for verification and reasoning.</jats:p
A global threats overview for Numeniini populations: synthesising expert knowledge for a group of declining migratory birds
The Numeniini is a tribe of thirteen wader species (Scolopacidae, Charadriiformes) of which seven are near-threatened or globally threatened, including two critically endangered. To help inform conservation management and policy responses, we present the results of an expert assessment of the threats that members of this taxonomic group face across migratory flyways. Most threats are increasing in intensity, particularly in non-breeding areas, where habitat loss resulting from residential and commercial development, aquaculture, mining, transport, disturbance, problematic invasive species, pollution and climate change were regarded as having the greatest detrimental impact. Fewer threats (mining, disturbance, problematic native species and climate change) were identified as widely affecting breeding areas. Numeniini populations face the greatest number of non-breeding threats in the East Asian-Australasian Flyway, especially those associated with coastal reclamation; related threats were also identified across the Central and Atlantic Americas, and East Atlantic flyways. Threats on the breeding grounds were greatest in Central and Atlantic Americas, East Atlantic and West Asian flyways. Three priority actions were associated with monitoring and research: to monitor breeding population trends (which for species breeding in remote areas may best be achieved through surveys at key non-breeding sites), to deploy tracking technologies to identify migratory connectivity, and to monitor land-cover change across breeding and non-breeding areas. Two priority actions were focused on conservation and policy responses: to identify and effectively protect key non-breeding sites across all flyways (particularly in the East Asian - Australasian Flyway), and to implement successful conservation interventions at a sufficient scale across human-dominated landscapes for species’ recovery to be achieved. If implemented urgently, these measures in combination have the potential to alter the current population declines of many Numeniini species and provide a template for the conservation of other groups of threatened species
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A novel transport mechanism for MOMP in Chlamydophila pneumoniae and its putative role in immune-therapy
Major outer membrane proteins (MOMPs) of Gram negative bacteria are one of the most intensively studied membrane proteins. MOMPs are essential for maintaining the structural integrity of bacterial outer membranes and in adaptation of parasites to their hosts. There is evidence to suggest a role for purified MOMP from Chlamydophila pneumoniae and corresponding MOMP-derived peptides in immune-modulation, leading to a reduced atherosclerotic phenotype in apoE−/− mice via a characteristic dampening of MHC class II activity. The work reported herein tests this hypothesis by employing a combination of homology modelling and docking to examine the detailed molecular interactions that may be responsible. A three-dimensional homology model of the C. pneumoniae MOMP was constructed based on the 14 transmembrane β-barrel crystal structure of the fatty acid transporter from Escherichia coli, which provides a plausible transport mechanism for MOMP. Ligand docking experiments were used to provide details of the possible molecular interactions driving the binding of MOMP-derived peptides to MHC class II alleles known to be strongly associated with inflammation. The docking experiments were corroborated by predictions from conventional immuno-informatic algorithms. This work supports further the use of MOMP in C. pneumoniae as a possible vaccine target and the role of MOMP-derived peptides as vaccine candidates for immune-therapy in chronic inflammation that can result in cardiovascular events
The influence of visual flow and perceptual load on locomotion speed
Visual flow is used to perceive and regulate movement speed during locomotion. We assessed the extent to which variation in flow from the ground plane, arising from static visual textures, influences locomotion speed under conditions of concurrent perceptual load. In two experiments, participants walked over a 12-m projected walkway that consisted of stripes that were oriented orthogonal to the walking direction. In the critical conditions, the frequency of the stripes increased or decreased. We observed small, but consistent effects on walking speed, so that participants were walking slower when the frequency increased compared to when the frequency decreased. This basic effect suggests that participants interpreted the change in visual flow in these conditions as at least partly due to a change in their own movement speed, and counteracted such a change by speeding up or slowing down. Critically, these effects were magnified under conditions of low perceptual load and a locus of attention near the ground plane. Our findings suggest that the contribution of vision in the control of ongoing locomotion is relatively fluid and dependent on ongoing perceptual (and perhaps more generally cognitive) task demands
Evaluation of appendicitis risk prediction models in adults with suspected appendicitis
Background
Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis.
Methods
A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis).
Results
Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent).
Conclusion
Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified
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