2,213 research outputs found
Constrained Statistical Modelling of Knee Flexion from Multi-Pose Magnetic Resonance Imaging
© 1982-2012 IEEE.Reconstruction of the anterior cruciate ligament (ACL) through arthroscopy is one of the most common procedures in orthopaedics. It requires accurate alignment and drilling of the tibial and femoral tunnels through which the ligament graft is attached. Although commercial computer-Assisted navigation systems exist to guide the placement of these tunnels, most of them are limited to a fixed pose without due consideration of dynamic factors involved in different knee flexion angles. This paper presents a new model for intraoperative guidance of arthroscopic ACL reconstruction with reduced error particularly in the ligament attachment area. The method uses 3D preoperative data at different flexion angles to build a subject-specific statistical model of knee pose. To circumvent the problem of limited training samples and ensure physically meaningful pose instantiation, homogeneous transformations between different poses and local-deformation finite element modelling are used to enlarge the training set. Subsequently, an anatomical geodesic flexion analysis is performed to extract the subject-specific flexion characteristics. The advantages of the method were also tested by detailed comparison to standard Principal Component Analysis (PCA), nonlinear PCA without training set enlargement, and other state-of-The-Art articulated joint modelling methods. The method yielded sub-millimetre accuracy, demonstrating its potential clinical value
Prospects for Improving the Intrinsic and Extrinsic Properties of Magnesium Diboride Superconducting Strands
The magnetic and transport properties of magnesium diboride films represent
performance goals yet to be attained by powder-processed bulk samples and
conductors. Such performance limits are still out of the reach of even the best
magnesium diboride magnet wire. In discussing the present status and prospects
for improving the performance of powder-based wire we focus attention on (1)
the intrinsic (intragrain) superconducting properties of magnesium diboride,
Hc2 and flux pinning, (2) factors that control the efficiency with which
current is transported from grain-to-grain in the conductor, an extrinsic
(intergrain) property. With regard to Item-(1), the role of dopants in Hc2
enhancement is discussed and examples presented. On the other hand their roles
in increasing Jc, both via Hc2 enhancement as well as direct
fluxoid/pining-center interaction, are discussed and a comprehensive survey of
Hc2 dopants and flux-pinning additives is presented. Current transport through
the powder-processed wire (an extrinsic property) is partially blocked by the
inherent granularity of the material itself and the chemical or other
properties of the intergrain surfaces. These and other such results indicate
that in many cases less than 15% of the conductor's cross sectional area is
able to carry transport current. It is pointed out that densification in
association with the elimination of grain-boundary blocking phases would yield
five-to ten-fold increases in Jc in relevant regimes, enabling the performance
of magnesium diboride in selected applications to compete with that of Nb-Sn
Molecular epidemiology and genotype distribution of Human Papillomavirus (HPV) among Arab women in the state of Qatar
Background: Human Papilloma Virus (HPV) infection is the major cause of cervical cancer worldwide.
With limited data available on HPV prevalence in the Arab countries, this study aimed to
identify the prevalence and genotypic distribution of HPV in the State of Qatar.
Methods: 3008 cervical samples, exclusively of women with Arabic origin residing in Qatar were
collected from the Women’s Hospital and Primary Health Care Corporation in Doha, State of
Qatar. HPV DNA detection was done using GP5+/6+ primers based real time-polymerase
chain reaction (RT-PCR) assay followed by the usage of HPV type specific primers based
RT- PCR reactions and Sanger sequencing for genotype identification.
Results: Similar prevalence rates of HPV infection was identified in both Qatari and non-Qatari
women at 6.2% and 5.9% respectively. HPV prevalence rate of 5.8% and 18.4% was
identified in women with normal cytology and in women with abnormal cytology
respectively. HPV 81, 11 and 16, in decreasing order were the most commonly identified
genotypes. HPV 81 was the most frequent low-risk genotype among women with both
normal (74.0%) and abnormal (33.3%) cytology. HPV 16 (4.6%) was identified as the
predominant high-risk HPV genotype among women with normal cytology and HPV 16,
HPV 18, and HPV 56 (22.2% each) were the most common identified high-risk genotypes in
women with abnormal cytology
Conclusions: The overall HPV prevalence in Arab women in Qatar was identified as 6.1% with an
increased HPV prevalence seen in women with abnormal cytology results and no significant
trends seen with age. In contrast to Western countries, we report a varied genotypic profile of
HPV with a high prevalence of low-risk HPV genotype 81 among the Arab women residing
in Qatar.Weill Cornell Medical College in Qatar; and by a grant from the Qatar National Research Fund (NPRP- 09-344-3-082)
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L1 transfer in the acquisition of manner and path in Spanish by native speakers of English
In this article the authors argue that L1 transfer from English is not only important in the early stages of L2 acquisition of Spanish, but remains influential in later stages if there is not enough positive evidence for the learners to progress in their development (Lefebvre, White, & Jourdan, 2006). The findings are based on analyses of path and manner of movement in stories told by British students of Spanish (N = 68) of three different proficiency levels. Verbs that conflate motion and path, on the one hand, are mastered early, possibly because the existence of Latinate path verbs, such as enter and ascend in English, facilitate their early acquisition by British learners of Spanish. Contrary to the findings of Cadierno (2004) and Cadierno and Ruiz (2006), the encoding of manner, in particular in boundary crossing contexts, seems to pose enormous difficulties, even among students who had been abroad on a placement in a Spanish-speaking country prior to the data collection. An analysis of the frequency of manner verbs in Spanish corpora shows that one of the key reasons why students struggle with manner is that manner verbs are so infrequent in Spanish. The authors claim that scarce positive evidence in the language exposed to and little or no negative evidence are responsible for the long-lasting effect of transfer on the expression of manner
Internet-based search of randomised trials relevant to mental health originating in the Arab world
BACKGROUND:
The internet is becoming a widely used source of accessing medical research through various on-line databases. This instant access to information is of benefit to busy clinicians and service users around the world. The population of the Arab World is comparable to that of the United States, yet it is widely believed to have a greatly contrasting output of randomised controlled trials related to mental health. This study was designed to investigate the existence of such research in the Arab World and also to investigate the availability of this research on-line.
METHODS:
Survey of findings from three internet-based potential sources of randomised trials originating from the Arab world and relevant to mental health care.
RESULTS:
A manual search of an Arabic online current contents service identified 3 studies, MEDLINE, EMBASE, and PsycINFO searches identified only 1 study, and a manual search of a specifically indexed, study-based mental health database, PsiTri, revealed 27 trials.
CONCLUSION:
There genuinely seem to be few trials from the Arab world and accessing these on-line was problematic. Replication of some studies that guide psychiatric/psychological practice in the Arab world would seem prudent
A systematic review of randomised controlled trials on the effectiveness of exercise programs on lumbo pelvic pain among postnatal women
Background: A substantial number of women tend to be affected by Lumbo Pelvic Pain (LPP) following child birth.
Physical exercise is indicated as a beneficial method to relieve LPP, but individual studies appear to suggest mixed
findings about its effectiveness. This systematic review aimed to synthesise evidence from randomised controlled trials on the effectiveness of exercise on LPP among postnatal women to inform policy, practice and future research.
Methods: A systematic review was conducted of all randomised controlled trials published between January 1990 and July 2014, identified through a comprehensive search of following databases: PubMed, PEDro, Embase, Cinahl, Medline, SPORTDiscus, Cochrane Pregnancy and Childbirth Group’s Trials Register, and electronic libraries of authors’institutions.
Randomised controlled trials were eligible for inclusion if the intervention comprised of postnatal exercise for women
with LPP onset during pregnancy or within 3 months after delivery and the outcome measures included changes in
LPP. Selected articles were assessed using the PEDro Scale for methodological quality and findings were synthesised narratively as meta-analysis was found to be inappropriate due to heterogeneity among included studies.
Results: Four randomised controlled trials were included, involving 251 postnatal women. Three trials were rated as
of ‘good’ methodological quality. All trials, except one, were at low risk of bias. The trials included physical exercise
programs with varying components, differing modes of delivery, follow up times and outcome measures. Intervention
in one trial, involving physical therapy with specific stabilising exercises, proved to be effective in reducing LPP
intensity. An improvement in gluteal pain on the right side was reported in another trial and a significant difference in
pain frequency in another.
Conclusion: Our review indicates that only few randomised controlled trials have evaluated the effectiveness of
exercise on LPP among postnatal women. There is also a great amount of variability across existing trials in the
components of exercise programs, modes of delivery, follow up times and outcome measures. While there is some
evidence to indicate the effectiveness of exercise for relieving LPP, further good quality trials are needed to ascertain
the most effective elements of postnatal exercise programs suited for LPP treatment
Metarhizium anisopliae Pathogenesis of Mosquito Larvae: A Verdict of Accidental Death
Metarhizium anisopliae, a fungal pathogen of terrestrial arthropods, kills the aquatic larvae of Aedes aegypti, the vector of dengue and yellow fever. The fungus kills without adhering to the host cuticle. Ingested conidia also fail to germinate and are expelled in fecal pellets. This study investigates the mechanism by which this fungus adapted to terrestrial hosts kills aquatic mosquito larvae. Genes associated with the M. anisopliae early pathogenic response (proteinases Pr1 and Pr2, and adhesins, Mad1 and Mad2) are upregulated in the presence of larvae, but the established infection process observed in terrestrial hosts does not progress and insecticidal destruxins were not detected. Protease inhibitors reduce larval mortality indicating the importance of proteases in the host interaction. The Ae. aegypti immune response to M. anisopliae appears limited, whilst the oxidative stress response gene encoding for thiol peroxidase is upregulated. Cecropin and Hsp70 genes are downregulated as larval death occurs, and insect mortality appears to be linked to autolysis through caspase activity regulated by Hsp70 and inhibited, in infected larvae, by protease inhibitors. Evidence is presented that a traditional host-pathogen response does not occur as the species have not evolved to interact. M. anisopliae retains pre-formed pathogenic determinants which mediate host mortality, but unlike true aquatic fungal pathogens, does not recognise and colonise the larval host
The images of psychiatry scale: development, factor structure, and reliability.
BACKGROUND: This analysis is based on a survey questionnaire designed to describe medical educators' views of psychiatry and psychiatrists. Our goals in this paper were to assess the psychometric properties of the survey questions by (a) using exploratory factor analysis to identify the basic factor structure underlying 37 survey items; (b) testing the resulting factor structure using confirmatory factor analysis; and (c) assessing the internal reliability of each identified factor. To our knowledge, this is the first attempt to use these techniques to psychometrically assess a scale measuring the strength of stigma that medical educators attached to psychiatry. METHODS: Survey data were collected from a random sample of 1,059 teaching faculty in 23 academic teaching sites in 15 countries. We conducted exploratory and confirmatory factor analysis to identify the scale structure and Cronbach's alpha to assess internal consistency of the resulting scales. RESULTS: Results showed that a two-factor solution was the best fit for the data. Following exploratory factor analysis, we conducted confirmatory factor analysis on a split half of the sample. Results highlighted several items with low loadings. Excluding factors with low correlations and allowing for several correlated variances resulted in a good fitting model explaining 95% of the variance in the data. CONCLUSIONS: We identified two unidimensional scales. The Images Scale contained 11 items measuring stereotypic content concerning psychiatry and psychiatrists. The Efficacy of Psychiatry Scale contained 5 items addressing perceptions of the challenges and effectiveness of psychiatry as a discipline
Antimicrobial Stewardship from Policy to Practice: Experiences from UK Antimicrobial Pharmacists
Antimicrobial stewardship in the UK has evolved dramatically in the last 15 years. Factors driving this include initial central funding for specialist pharmacists and mandatory reductions in healthcare-associated infections (particularly Clostridium difficile infection). More recently, the introduction of national stewardship guidelines, and an increased focus on stewardship as part of the UK five-year antimicrobial resistance strategy, have accelerated and embedded developments. Antimicrobial pharmacists have been instrumental in effecting changes at an organizational and national level. This article describes the evolution of the antimicrobial pharmacist role, its impact, the progress toward the actions listed in the five-year resistance strategy, and novel emerging areas in stewardship in the UK
Alcohol and other drug use before custody among Aboriginal and non-Aboriginal people in New South Wales, Australia.
OBJECTIVE: Alcohol and other drug (AoD) use is a significant factor in the poor health status of people in prison. Our aim is to explore associations of alcohol consumption with tobacco and illicit drug use among Aboriginal and non-Aboriginal people in prison to inform health services, clinical care and support. METHODS: We analysed the alcohol, tobacco and illicit drug use data of the 2015 Network Patient Health Survey of adults in custody in New South Wales (n=1,132). A comparative analysis of Aboriginal to non-Aboriginal participants including bi-variant and multivariant analysis was undertaken. RESULTS: Significantly more Aboriginal than non-Aboriginal participants reported alcohol consumption before prison that was consistent with possible dependence. More Aboriginal than non-Aboriginal participants used cannabis on a daily or almost on daily basis before prison. There was significant association between alcohol and cannabis use among Aboriginal participants. CONCLUSIONS: There are differences in Aboriginal and non-Aboriginal AoD use patterns, which should be considered when providing treatment and support programs within and post-release from prison. IMPLICATIONS FOR PUBLIC HEALTH: Specific programs are needed to assist Aboriginal people in this population who co-use alcohol and cannabis
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