312 research outputs found

    The Intervertebral Disc and Low Back Pain

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    Low back pain has an enormous socioeconomic impact in this country. Even with advancement in diagnostic technology, the incidence and severity of low back pain continues to increase. The intervertebral disc plays an important causative role in the production of low back pain. The intervertebral disc may cause direct discogenic pain by mechanical and/or chemical irritation of the nociceptor receptors found within the outer one-third of the annulus fibrosis, or cause back pain by an indirect method. The incidence of low back pain is first reported around the age of 25 and is most prevalent from ages 35-60. It is during this time that the intervertebral disc is in its semi-fluid state and possesses high intradiskal pressure. The results of this research of the literature suggest that it is crucial to maintain the integrity of the intervertebral disc to prevent low back pain. This is done by avoiding the positions and activities that increase intradiskal pressure, and by an adequate exercise routine consisting of walking and isometric trunk strengthening

    Preservice teachers’ pictorial strategies for a multistep multiplicative fraction problem

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    Previous research has documented that preservice teachers (PSTs) struggle with under- standing fraction concepts and operations, and misconceptions often stem from their understanding of the referent whole. This study expands research on PSTs’ understanding of wholes by investigating pictorial strategies that 85 PSTs constructed for a multistep fraction task in a multiplicative context. The results show that many PSTs were able to construct valid pictorial strategies, and the strategies were widely diverse with respect to how they made sense of an unknown referent whole of a fraction in multiple steps, how they represented the wholes in their drawings, in which order they did multiple steps, and which type of model they used (area or set). Based on their wide range of pictorial strategies, we discuss potential benefits of PSTs’ construction of their own representations for a word problem in developing problem solving skills

    Free energy barrier for melittin reorientation from a membrane-bound state to a transmembrane state

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    An important step in a phospholipid membrane pore formation by melittin antimicrobial peptide is a reorientation of the peptide from a surface into a transmembrane conformation. In this work we perform umbrella sampling simulations to calculate the potential of mean force (PMF) for the reorientation of melittin from a surface-bound state to a transmembrane state and provide a molecular level insight into understanding peptide and lipid properties that influence the existence of the free energy barrier. The PMFs were calculated for a peptide to lipid (P/L) ratio of 1/128 and 4/128. We observe that the free energy barrier is reduced when the P/L ratio increased. In addition, we study the cooperative effect; specifically we investigate if the barrier is smaller for a second melittin reorientation, given that another neighboring melittin was already in the transmembrane state. We observe that indeed the barrier of the PMF curve is reduced in this case, thus confirming the presence of a cooperative effect

    Clinical effectiveness of a sedation protocol minimizing benzodiazepine infusions and favoring early dexmedetomidine: A before-after study

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    INTRODUCTION: Randomized controlled trials suggest clinical outcomes may be improved with dexmedetomidine as compared to benzodiazepines, however further study and validation is needed. The objective of this study was to determine the clinical effectiveness of a sedation protocol minimizing benzodiazepine use in favor of early dexmedetomidine. METHODS: This was a before-after study including adult surgical and medical ICU patients requiring mechanical ventilation and continuous sedation for at least 24 hours. The before phase included consecutive patients admitted between April 1 and August 31, 2011. Subsequently, the protocol was modified to minimize use of benzodiazepines in favor of early dexmedetomidine through a multidisciplinary approach and staff education was provided. The after phase included consecutive eligible patients between May 1 and October 31, 2012. RESULTS: 199 patients were included, with 97 patients in the before and 102 in the after phase. Baseline characteristics were well balanced between groups. Use of midazolam as initial sedation (58% vs. 27%, p \u3c 0.0001) or at any point during the ICU stay (76% vs. 48%, p \u3c 0.0001) was significantly reduced in the after phase. Dexmedetomidine use as initial sedation (2% vs. 39%, p \u3c 0.0001) or at any point during the ICU stay (39% vs. 82%, p \u3c 0.0001) significantly increased. Both the prevalence (81% vs. 93%, p =0.013) and median percent of days with delirium (55% (IQR 18-83) vs. 71% (IQR 45-100), p = 0.001) were increased in the after phase. The median duration of mechanical ventilation was significantly reduced in the after phase (110 (IQR 59-192) vs. 74.5 (IQR 42-148) hrs, p = 0.029) and significantly fewer patients required tracheostomy (20% vs. 9%, p = 0.040). The median ICU length of stay was 8 (IQR 4-12) days in the before phase and 6 (IQR 3-11) days in the after phase (p = 0.252). CONCLUSIONS: Implementing a sedation protocol that targeted light sedation and reduced benzodiazepine use led to significant improvements in the duration of mechanical ventilation and requirement for tracheostomy despite increases in the prevalence and duration of ICU delirium

    Protocol for a prospective, observational cohort study of awareness in mechanically ventilated patients admitted from the emergency department: The ED-AWARENESS study

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    INTRODUCTION: Awareness with paralysis is a complication with potentially devastating psychological consequences for mechanically ventilated patients. While rigorous investigation into awareness has occurred for operating room patients, little attention has been paid outside of this domain. Mechanically ventilated patients in the emergency department (ED) have been historically managed in a way that predisposes them to awareness events: high incidence of neuromuscular blockade use, underdosing of analgesia and sedation, delayed administration of analgesia and sedation after intubation, and a lack of monitoring of sedation targets and depth. These practice patterns are discordant to recommendations for reducing the incidence of awareness, suggesting there is significant rationale to examine awareness in the ED population. METHODS AND ANALYSIS: This is a single centre, prospective cohort study examining the incidence of awareness in mechanically ventilated ED patients. A cohort of 383 mechanically ventilated ED patients will be included. The primary outcome is awareness with paralysis. Qualitative reports of all awareness events will be provided. Recognising the potential problem with conventional multivariable analysis arising from a small number of events (expected less than 10-phenomenon of separation), Firth penalised method, exact logistic regression model or penalised maximum likelihood estimation shrinkage (Ridge, LASSO) will be used to assess for predictors of awareness. ETHICS AND DISSEMINATION: Approval of the study by the Human Research Protection Office has been obtained. This work will be disseminated by publication of peer-reviewed manuscripts, presentation in abstract form at scientific meetings and data sharing with other investigators through academically established means

    Workforce Projections 2010-2020: Annual Supply and Demand Forecasting Models for Physical Therapists Across the United States

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    BACKGROUND: Health human resources continue to emerge as a critical health policy issue across the United States. OBJECTIVE: The purpose of this study was to develop a strategy for modeling future workforce projections to serve as a basis for analyzing annual supply of and demand for physical therapists across the United States into 2020. DESIGN: A traditional stock-and-flow methodology or model was developed and populated with publicly available data to produce estimates of supply and demand for physical therapists by 2020. METHODS: Supply was determined by adding the estimated number of physical therapists and the approximation of new graduates to the number of physical therapists who immigrated, minus US graduates who never passed the licensure examination, and an estimated attrition rate in any given year. Demand was determined by using projected US population with health care insurance multiplied by a demand ratio in any given year. The difference between projected supply and demand represented a shortage or surplus of physical therapists. RESULTS: Three separate projection models were developed based on best available data in the years 2011, 2012, and 2013, respectively. Based on these projections, demand for physical therapists in the United States outstrips supply under most assumptions. LIMITATIONS: Workforce projection methodology research is based on assumptions using imperfect data; therefore, the results must be interpreted in terms of overall trends rather than as precise actuarial data-generated absolute numbers from specified forecasting. CONCLUSIONS: Outcomes of this projection study provide a foundation for discussion and debate regarding the most effective and efficient ways to influence supply-side variables so as to position physical therapists to meet current and future population demand. Attrition rates or permanent exits out of the profession can have important supply-side effects and appear to have an effect on predicting future shortage or surplus of physical therapists

    The landscape of a Swedish boat-grave cemetery

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    This is the published PDF version of an article published in Landscapes© 2010. The definitive version is available at http://www.maneyonline.com/toc/lan/11/1The paper integrates topographical and experiential approaches to the mortuary landscape of a Viking period inhumation-grave excavated in 2005 within the cemetery at Skamby, Kuddy parish, Östergötland province, Sweden. We argue that the landscape context was integral to the performance of the funerary ceremonies and the subsequent monumental presence of the dead in the landscape. We offer a way to move beyond monocausal explanations for burial location based on single-scale analyses. Instead, we suggest that boat-inhumation at Skamby was a commemorative strategy that operated on multiple scales and drew its significance from multiple landscape attributes.British Academ
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