2,110 research outputs found
Masticatory biomechanics in the rabbit : a multi-body dynamics analysis
Acknowledgement We thank Sue Taft (University of Hull) for the ĀµCT-scanning of the rabbit specimen used in this study. We also thank RaphaĆ«l Cornette, Jacques Bonnin, Laurent Dufresne, and l'Amicale des Chasseurs Trappistes (ACT) for providing permission and helping us capture the rabbits used for the in vivo bite force measurements at la RĆ©serve Naturelle Nationale de St Quentin en Yvelines, France.Peer reviewedPublisher PD
Systematic review of trends in emergency department attendances : an Australian perspective
Emergency departments (EDs) in many developed countries are experiencing increasing pressure due to rising numbers of patient presentations and emergency admissions. Reported increases range up to 7% annually. Together with limited inpatient bed capacity, this contributes to prolonged lengths of stay in the ED; disrupting timely access to urgent care, posing a threat to patient safety. The aim of this review is to summarise the findings of studies that have investigated the extent of and the reasons for increasing emergency presentations. To do this, a systematic review and synthesis of published and unpublished reports describing trends and underlying drivers associated with the increase in ED presentations in developed countries was conducted. Most published studies provided evidence of increasing ED attendances within developed countries. A series of inter-related factors have been proposed to explain the increase in emergency demand. These include changes in demography and in the organisation and delivery of healthcare services, as well as improved health awareness and community expectations arising from health promotion campaigns. The factors associated with increasing ED presentations are complex and inter-related and include rising community expectations regarding access to emergency care in acute hospitals. A systematic investigation of the demographic, socioeconomic and health-related factors highlighted by this review is recommended. This would facilitate untangling the dynamics of the increase in emergency demand
Resolving the Surfaces of Extrasolar Planets With Secondary Eclipse Light Curves
We present a method that employs the secondary eclipse light curves of
transiting extrasolar planets to probe the spatial variation of their thermal
emission. This technique permits an observer to resolve the surface of the
planet without the need to spatially resolve its central star. We evaluate the
feasibility of this technique for the HD 209458 system [..]. We consider two
representations of the planetary thermal emission; a simple model parameterized
by a sinusoidal dependence on longitude and latitude, as well as the results of
a three-dimensional dynamical simulation of the planetary atmosphere previously
published by Cooper & Showman. We find that observations of the secondary
eclipse light curve are most sensitive to a longitudinal offset in the
geometric and photometric centroids of the hemisphere of the planet visible
near opposition. To quantify this signal, we define a new parameter, the
``uniform time offset,'' which measures the time lag between the observed
secondary eclipse and that predicted by a planet with a uniform surface flux
distribution. We compare the predicted amplitude of this parameter for HD
209458 with the precision with which it could be measured with IRAC. We find
that IRAC observations at 3.6um a single secondary eclipse should permit
sufficient precision to confirm or reject the Cooper & Showman model of the
surface flux distribution for this planet. We quantify the signal-to-noise
ratio for this offset in the remaining IRAC bands (4.5um, 5.8um, and 8.0um),
and find that a modest improvement in photometric precision (as might be
realized through observations of several eclipse events) should permit a
similarly robust detection.Comment: AASTeX 5.2, 24 pages, 5 figures, accepted for publication in ApJ; v2:
clarifications, updated to version accepted by ApJ; v3: try to reduce spacin
Differential Signaling Profiles of MC4R Mutations with Three Different Ligands
The melanocortin 4 receptor (MC4R) is a key player in hypothalamic weight regulation and energy expenditure as part of the leptin-melanocortin pathway. Mutations in this G protein coupled receptor (GPCR) are the most common cause for monogenetic obesity, which appears to be mediated by changes in the anorectic action of MC4R via GS-dependent cyclic adenosine-monophosphate (cAMP) signaling as well as other signaling pathways. To study potential bias in the effects of MC4R mutations between the different signaling pathways, we investigated three major MC4R mutations: a GS loss-of-function (S127L) and a GS gain-of-function mutant (H158R), as well as the most common European single nucleotide polymorphism (V103I). We tested signaling of all four major G protein families plus extracellular regulated kinase (ERK) phosphorylation and Ī²-arrestin2 recruitment, using the two endogenous agonists, Ī±- and Ī²-melanocyte stimulating hormone (MSH), along with a synthetic peptide agonist (NDP-Ī±-MSH). The S127L mutation led to a full loss-of-function in all investigated pathways, whereas V103I and H158R were clearly biased towards the Gq/11 pathway when challenged with the endogenous ligands. These results show that MC4R mutations can cause vastly different changes in the various MC4R signaling pathways and highlight the importance of a comprehensive characterization of receptor mutations
Collecting, analyzing and archiving of ground based infrared solar spectra obtained from several locations
The infrared solar spectrum as observed from the ground under high resolution contains thousands of absorption lines. The majority of these lines are due to compounds that are present in the Earth's atmosphere. Ground based infrared solar spectra contain information concerning the composition of the atmosphere at the time the spectra were obtained. The objective of this program is to record solar spectra from various ground locations, and to analyze and archive these spectra. The analysis consists of determining, for as many of the absorption lines as possible, the molecular species responsible for the absorption, and to verify that current models of infrared transmission match the observed spectra. Archiving is an important part of the program, since a number of the features in the spectra have not been identified. At some later time, when the features are identified, it will be possible to determine the amount of that compound that was present in the atmosphere at the time the spectrum was taken
Familyā and populationālevel responses to atmospheric CO2 concentration: gas exchange and the allocation of C, N, and biomass in Plantago lanceolata (Plantaginaceae)
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142197/1/ajb21080.pd
Correctness and response time distributions in the MemTrax continuous recognition task: Analysis of strategies and a reverse-exponential model
A critical issue in addressing medical conditions is measurement. Memory measurement is difficult, especially episodic memory, which is disrupted by many conditions. On-line computer testing can precisely measure and assess several memory functions. This study analyzed memory performances from a large group of anonymous, on-line participants using a continuous recognition task (CRT) implemented at https://memtrax.com. These analyses estimated ranges of acceptable performance and average response time (RT). For 344,165 presumed unique individuals completing the CRT a total of 602,272 times, data were stored on a server, including each correct response (HIT), Correct Rejection, and RT to the thousandth of a second. Responses were analyzed, distributions and relationships of these parameters were ascertained, and mean RTs were determined for each participant across the population. From 322,996 valid first tests, analysis of correctness showed that 63% of these tests achieved at least 45 correct (90%), 92% scored at or above 40 correct (80%), and 3% scored 35 correct (70%) or less. The distribution of RTs was skewed with 1% faster than 0.62 s, a median at 0.890 s, and 1% slower than 1.57 s. The RT distribution was best explained by a novel model, the reverse-exponential (RevEx) function. Increased RT speed was most closely associated with increased HIT accuracy. The MemTrax on-line memory test readily provides valid and reliable metrics for assessing individual episodic memory function that could have practical clinical utility for precise assessment of memory dysfunction in many conditions, including improvement or deterioration over time
Characterization and localization of antigens for serodiagnosis of human paragonimiasis
Paragonimiasis is a foodborne trematode infection that affects 23 million people, mainly in Asia. Lung fluke infections lead frequently to chronic cough with fever and hemoptysis, and are often confused with lung cancer or tuberculosis. Paragonimiasis can be efficiently treated with praziquantel, but diagnosis is often delayed, and patients are frequently treated for other conditions. To improve diagnosis, we selected five Paragonimus kellicotti proteins based on transcriptional abundance, recognition by patient sera, and conservation among trematodes and expressed them as His-fusion proteins in Escherichia coli. Sequences for these proteins have 76-99% identity with amino acid sequences for orthologs in the genomes of Paragonimus westermani, Paragonimus heterotremus, and Paragonimus miyazakii. Immunohistology studies showed that antibodies raised to four recombinant proteins bound to the tegument of adult P. kellicotti worms, at the parasite host interface. Only a known egg antigen was absent from the tegument but present in developing and mature eggs. We evaluated the diagnostic potential of these antigens by Western blot with sera from patients with paragonimiasis (from MO and the Philippines), fascioliasis, and schistosomiasis, and with sera from healthy North American controls. Two recombinant proteins (a cysteine protease and a myoglobin) showed the highest sensitivity and specificity as diagnostic antigens, and they detected antibodies in sera from paragonimiasis patients with early or mature infections. In contrast, antibodies to egg yolk ferritin appeared to be specific marker for patients with adult fluke infections that produce eggs. Our study has identified and localized antigens that are promising for serodiagnosis of human paragonimiasis
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