Understanding the Role of Personal, Psychosocial and Occupational Factors and their Interactions on Low Back Pain Severity in Workers

Low back pain (LBP) is the most prevalent work-related musculoskeletal disorder. Occupational risk factors have been studied for current ergonomic prevention strategies; however, other underlying mechanisms may exist since not all workers performing the same task develop the same severity. Previous research has identified personal and psychosocial risk factors that also contribute to LBP. Research quantifying the interactive effects of the various personal, psychosocial and occupational factors is limited, along with research on the effect of risk factor combinations on LBP severity. The objectives of this study were to: 1) study the various factors that are known to be involved in low back pain and analyze interactions, and 2) develop a model to predict low back pain and validate it. In order to address these objectives, 2 studies were conducted. The first study investigated the effects of various personal, genetic, occupational and psychosocial factors on two subjective LBP severity ratings: Oswestry Disability Index (ODI) and a Visual Analog Scale (VAS), and three physician-based ratings: MRI severity, canal stenosis and nerve impingement. Personal and psychosocial factors, in addition to occupational factors, were found to significantly affect the severity ratings. The second study involved building predictive models of LBP severity for each risk factor category as well as a combined risk factor model. Results showed that the combined risk factor models considering interaction effects both within and across risk factor categories were significantly better in predicting severity ratings than the individual models. However, validation conducted using 5 random samples showed inconsistent accuracies. Results obtained may help to develop a more reliable way to predict and, hence, prevent chronic LBP

Understanding the Role of Personal, Psychosocial and Occupational Factors and their Interactions on Low Back Pain Severity in Workers

Low back pain (LBP) is the most prevalent work-related musculoskeletal disorder. Occupational risk factors have been studied for current ergonomic prevention strategies; however, other underlying mechanisms may exist since not all workers performing the same task develop the same severity. Previous research has identified personal and psychosocial risk factors that also contribute to LBP. Research quantifying the interactive effects of the various personal, psychosocial and occupational factors is limited, along with research on the effect of risk factor combinations on LBP severity. The objectives of this study were to: 1) study the various factors that are known to be involved in low back pain and analyze interactions, and 2) develop a model to predict low back pain and validate it. In order to address these objectives, 2 studies were conducted. The first study investigated the effects of various personal, genetic, occupational and psychosocial factors on two subjective LBP severity ratings: Oswestry Disability Index (ODI) and a Visual Analog Scale (VAS), and three physician-based ratings: MRI severity, canal stenosis and nerve impingement. Personal and psychosocial factors, in addition to occupational factors, were found to significantly affect the severity ratings. The second study involved building predictive models of LBP severity for each risk factor category as well as a combined risk factor model. Results showed that the combined risk factor models considering interaction effects both within and across risk factor categories were significantly better in predicting severity ratings than the individual models. However, validation conducted using 5 random samples showed inconsistent accuracies. Results obtained may help to develop a more reliable way to predict and, hence, prevent chronic LBP

Serum uric acid as a prognostic indicator in acute ischemic stroke

Background: Association between serum uric acid (SUA) and the outcome of acute ischemic stroke is debated and needs to be evaluated. The present study was conducted to study the serum uric acid concentration as an indicator of   outcome among acute ischaemic stroke and to determine the role of serum uric acid as a risk factor for acute ischemic stroke.Methods: An observational study where 50 patients who presented within 48 hours of onset of stroke admitted to medical wards of government general Hospital Guntur were selected for the study.Results: Out of 50 patients included for the study, 6 belonged to the age group of 30-40 years. Majority were male (66%) and 44.5% of the males and 76.5% of females showed raised serum uric acid levels. 25 out of 50 patients were diabetic (i.e. 50%) Among them 16 had serum uric acid >6 mg% (ie.64%), 56% of the patients were hypertensive and among them 71% were found to have uric acid levels greater than 6mgs%, 38 out of 50 patients had bad outcome, with elevated uric acid levels found 30 among them. In the present study, BMI and outcome of Stroke were significantly associated with Serum Uric acid levels.Conclusions: Serum uric acid levels can be used as a prognostic indicator as a marker for increased risk of stroke. Elevated serum urate concentration may stratify risk of death after acute stroke

Least squares approximations of measures via geometric condition numbers

For a probability measure on a real separable Hilbert space, we are interested in "volume-based" approximations of the d-dimensional least squares error of it, i.e., least squares error with respect to a best fit d-dimensional affine subspace. Such approximations are given by averaging real-valued multivariate functions which are typically scalings of squared (d+1)-volumes of (d+1)-simplices. Specifically, we show that such averages are comparable to the square of the d-dimensional least squares error of that measure, where the comparison depends on a simple quantitative geometric property of it. This result is a higher dimensional generalization of the elementary fact that the double integral of the squared distances between points is proportional to the variance of measure. We relate our work to two recent algorithms, one for clustering affine subspaces and the other for Monte-Carlo SVD based on volume sampling

A Dangerous and Unrecognized Interaction of Apixaban

Direct oral anticoagulants (DOACs) drug-to-drug interactions are underrecognized by clinicians. Apixaban has cytochrome 450 (CYP) mediated metabolism (primarily by CYP3A4). Strong inducers and inhibitors of this enzyme may cause variations in the blood level of apixaban. This report presents a patient who received a femoral artery stent and developed a large retroperitoneal hemorrhage after she was prescribed apixaban in addition to her antiretroviral therapy (AVT) regimen that included cobicistat, a strong CYP3A4 inhibitor. The patient was managed conservatively, and a repeat computed tomography scan in a subsequent admission revealed near resolution of the hematoma. The treating physicians realized that apixaban should not be prescribed with a potent CYP3A4 inhibitor like cobicistat and discontinued it

DRAINAGE BEHAVIOR OF AQUEOUS, POLYMERIC, AND OIL-BASED NITROGEN FOAMS: THEORETICAL AND EXPERIMENTAL INVESTIGATION

Foams can be formulated to have a wide range of densities and viscosities. This unique behavior makes foam suitable for underbalanced drilling where pressure exerted on formation is maintained below pore pressure and at the same time, favorable conditions for a good hole-cleaning can be established in the wellbore. Foams are also used as in fracturing, cementing, and, enhanced oil recovery applications. However, the disadvantage of foam is its inherent instability. The stability of aqueous foams in vertical conduits has been extensively investigated. However, in many industrial applications such as underbalanced drilling foam is used in inclined configurations. The stability of foams inclined conduits is not well understood. The effect of geometry is often ignored. In addition, polymer-based and non-aqueous foams with more complex flow and stability behavior are becoming more common. As a result, there is a strong need to investigate foams to better understand the effects of different operational factors (inclination, conduit geometry, base fluid type, and shearing) on their stability. Thus, the main goal of this study is to investigate each of these factors with respect to their impact on foam stability. To achieve this, foam stability experiments were conducted in concentric annulus and straight pipe sections. The pipe section is manufactured from a fully transparent PVC pipe, enabling visual inspection of foam structure and liquid drainage. The annulus is made of stainless steel casing and a rotating inner PTFE (polytetrafluoroethylene) rod. Three types of foams (aqueous, polymeric-based and oil-based foams) were used in the investigation. All tests were performed at 400 KPa and ambient temperature (22 ± 2oC). Foam quality was ranged from 40 - 80%, except for oil-based foam which was limited to 70% due to instability at high qualities. Foam rheology data was obtained from pipe viscometers before conducting stability tests. Two inclination angles (0o and 30o) were considered in this study. For tests conducted in the annulus, the rotation speed of the inner rod was varied (0, 4, and 7 rpm) to examine the impact of shearing on foam stability. Hydrostatic pressure data measured from the annular test section is converted into density profiles, which are used to determine the drained liquid volume as a function of time. In straight pipe sections, the volume of drained liquid was measured using a measuring tape. A digital camera with a microscope was used to capture images of foam in real-time to examine the process of foam decay (i.e. the degree of bubble coarsening and coalescence). Foam stability increased with quality. For a given quality, foam prepared with polymeric fluid was the most stable, while oil-based foam was the least. The wall effects can hinder bubble and drained liquid motion and consequently delay drainage. As a result, foam drained more slowly in the annulus than in pipe. Inclining the test sections resulted in much faster drainage, possibly due to the formation of a liquid layer between foam structure and container walls that flows down due to gravity, effectively avoiding the hydraulic flow resistance of foam structure. The effect of shearing on drainage was minimal for the level of shear rate applied. Channel-dominated model developed in this study is suitable for all foams considered (40-80%). Node-dominated model is not recommended for these wet foams as it tends to over predict liquid volume fractions at early time steps

It Is Not a Boerhaave! A Case of Spontaneous Pneumothorax

Spontaneous pneumothorax is a pneumothorax that is not caused by trauma or an apparent precipitating factor. This report presents a case of a 91-year-old man with no history of lung disease who developed pneumothorax after two days of persistent nausea and vomiting. He was misdiagnosed as a case of Boerhaave\u27s syndrome. A chest computed tomography with iohexol oral contrast showed no evidence of esophageal rupture, and an upper endoscopy revealed a small gastric ulcer and no gastric outlet obstruction. The patient was managed conservatively; his spontaneous pneumothorax, nausea, and vomiting resolved