1,085 research outputs found
The Retail FX Trader: Random Trading and the Negative Sum Game
With the internet boom of early 2000 making access to trading the Foreign Exchange (FX) market far simpler for members of the general public, the growth of 'retail' FX trading continues, with daily transaction volumes as high as $200 billion. Potential new entrants to the retail FX trading world may come from the recent UK pension deregulations, further increasing the volumes. The attraction of FX trading is that it offers high returns and whilst it has been understood that it is high-risk in nature, the rewards are seen as being commensurately high for the 'skilled and knowledgeable' trader who has an edge over other market participants. This paper analyses a number of independent sources of data and previous research, to examine the profitability of the Retail FX trader and compares the results with that of a simulated random trading models. This paper finds evidence to suggest that whilst approximately 20% of traders can expect to end up with a profitable account, around 40% might expect their account to be subject to a margin call. This paper finds a strong correlation between the overall profitability of traders and impact of the cost of the bid-ask spread, whilst finding little if any evidence that retail FX traders, when viewed as a group, are achieving results better than that from random trading
Getting the message straight: effects of a brief hepatitis prevention intervention among injection drug users
To redress gaps in injection drug users' (IDUs) knowledge about hepatitis risk and prevention, we developed a brief intervention to be delivered to IDUs at syringe exchange programs (SEPs) in three US cities. Following a month-long campaign in which intervention packets containing novel injection hygiene supplies and written materials were distributed to every client at each visit, intervention effectiveness was evaluated by comparing exposed and unexposed participants' self-reported injection practices. Over one-quarter of the exposed group began using the novel hygiene supplies which included an absorbent pad ("Safety Square") to stanch blood flow post-injection. Compared to those unexposed to the intervention, a smaller but still substantial number of exposed participants continued to inappropriately use alcohol pads post-injection despite exposure to written messages to the contrary (22.8% vs. 30.0%). It should also be noted that for those exposed to the intervention, 8% may have misused Safety Squares as part of pre-injection preparation of their injection site; attention should be paid to providing explicit and accurate instruction on the use of any health promotion materials being distributed. While this study indicates that passive introduction of risk reduction materials in injection drug users through syringe exchange programs can be an economical and relatively simple method of changing behaviors, discussions with SEP clients regarding explicit instructions about injection hygiene and appropriate use of novel risk reduction materials is also needed in order to optimize the potential for adoption of health promotion behaviors. The study results suggest that SEP staff should provide their clients with brief, frequent verbal reminders about the appropriate use when distributing risk reduction materials. Issues related to format and language of written materials are discussed
The Impact of the Laterality on Radiographic Outcomes of the Bernese Periacetabular Osteotomy
The purpose of this study was to compare the pre and postoperative radiographic findings and analyze the complication rate with respect to the laterality in periacetabular osteotomy in right-handed surgeons. Satisfaction rate and radiographic findings were prospectively collected between 2017 and 2019 and retrospectively reviewed. For analysis, all measurements of the CT scans were performed by a musculoskeletal fellowship-trained radiologist. Complications were classified into two categories: perioperative or postoperative. All surgeries were performed by three right-hand dominant hip surgeons. A total of 41 dysplastic hips (25 right and 16 left hips) in 33 patients were included. Postoperatively, a significantly lower acetabular index angle on the left side was observed at -2.6 +/- 4.3 as compared to the right side at 1.6 +/- 6.5 (p < 0.05). The change in Center edge (CE) angle was significantly lower for the left side 13.7 +/- 5.5 degrees than on the right side, measured at 18.4 +/- 7.3 (p < 0.001); however, the overall CE angle was comparable at 38.5 +/- 8.9 degrees without any significant difference between the operated hips (left side at 37.8 +/- 6.1 degrees versus right side at 39.0 +/- 10.3; p = 0.340). No significant differences in other radiographic measurements or surgical time were observed. For complications, the right side was more commonly affected, which may also explain a higher satisfaction rate in patients who were operated on the left hip with 92.3%. The change in lateral CE angle was significantly lower for the left side and the right hip seems to be predisposed to complications, which correlate with a lower satisfaction rate in right-handed surgeons
Rotational abnormalities in dysplastic hips and how to predict acetabular torsion
Objectives: The aim of this study was to investigate the degree to which conventional radiography can represent the acetabular and femoral rotational alignment profile between dysplastic and borderline-dysplastic hips.
Methods: A retrospective trial was conducted including 56 borderline-dysplastic and dysplastic hips at a mean age of 28.9 years (range from 18 to 46). Inclusion criteria consisted of symptomatic patients with hip dysplasia undergoing 2-dimensional radiography as well as computed tomography. On radiography, the lateral center edge angle, acetabular hip index, hip lateralization index, acetabular index angle, and the Sharp angle were measured, and the presence of a crossover sign was noted. In computed tomography, the full rotational profile of the lower limb was measured.
Results: Significant correlations were observed in the overall analysis between the anteversion of the acetabulum and the hip lateralization index (mean 0.56, coefficient of regression (CoR) -32.35, p = 0.011) as well as the acetabular index angle with a mean of 11.50 (CoR 0.544, p = 0.018). Similar results were found in the subgroup of dysplastic hips with an acetabular index angle of 13.9 (p = 0.013, CoR 0.74). For the borderline-dysplastic group, no significant correlations between the pelvis radiography and rotational CT were seen.
Conclusion: Although the femoral and acetabular torsion cannot be predicted from x-rays, the anteversion of the acetabulum correlates with the acetabular index angle, the hip lateralization index, and eventually the beta angle in dysplastic hips. For borderline-dysplastic hips, such results did not show up, which strongly illustrates the need for computed tomography in these cases
Psychosocial and contextual correlates of opioid overdose risk among drug users in St. Petersburg, Russia
<p>Abstract</p> <p>Background</p> <p>Opioid overdose in Russia is a problem that has grown more severe as heroin abuse expanded over the past decade, yet few studies have explored it in detail. In order to gain a clearer understanding of the situation, 60 drug users, both in and out of drug treatment in St. Petersburg, were interviewed concerning their overdose experience and knowledge about overdose recognition and prevention.</p> <p>Methods</p> <p>Using a semi-structured interview, we sought to identify and describe local attitudes, knowledge and experience (both self-sustained and witnessed) of opioid overdose. Bi-variate and multiple logistic regressions were performed in order to identify the relationship between overdose experience and sociodemographic factors, risk behaviors, and clinical psychiatric measures.</p> <p>Results</p> <p>We found that having experienced or witnessed an opioid overdose within the previous year was common, overdose knowledge was generally high, but nearly half the participants reported low self-efficacy for effectively intervening in an overdose situation. In bivariate analyses, self-reported family problems (i.e., perceived problematic family interactions) were positively associated with both experiencing (t<sub>56 </sub>= 2.49; p < 0.05) and with witnessing a greater number of overdoses in the previous year (rho<sub>s </sub>= 0.31; p < 0.05). Having previously overdosed [Adjusted Risk Ratio (ARR) 1.7, 95% Confidence Interval (CI) 1.1–2.6] and higher SCL-90-R somatization scores (ARR 1.2, 95% CI 0.96 – 1.5) were independently associated in multivariable analyses with self-sustained overdose experience in the past year. Greater perceived likelihood of experiencing a future overdose and concern about medical problems were independently associated with witnessing a higher number of overdoses within the previous year. Over two thirds of the participants expressed interest in receiving training in overdose prevention and response.</p> <p>Conclusion</p> <p>Opioid overdose experience is very common among drug users in St. Petersburg, Russia, and interest in receiving training for overdose recognition and prevention was high. Future research should target the development of effective overdose recognition and prevention interventions, especially ones that include naloxone distribution and involve drug users' families.</p
The Impact of Hip Dysplasia on CAM Impingement
Predisposing factors for CAM-type femoroacetabular impingement (FAI) include acetabular protrusion and retroversion; however, nothing is known regarding development in dysplastic hips. The purpose of this study was to determine the correlation between CAM-type FAI and developmental dysplastic hips diagnosed using X-ray and rotational computed tomography. In this retrospective study, 52 symptomatic hips were included, with a mean age of 28.8 +/- 7.6 years. The inclusion criteria consisted of consecutive patients who suffered from symptomatic dysplastic or borderline dysplastic hips and underwent a clinical examination, conventional radiographs and rotational computed tomography. Demographics, standard measurements and the rotational alignments were recorded and analyzed between the CAM and nonCAM groups. Among the 52 patients, 19 presented with CAM impingement, whereas, in 33 patients, no signs of CAM impingement were noticed. For demographics, no significant differences between the two groups were identified. On conventional radiography, the acetabular hip index as well as the CE angle for the development of CAM impingement were significantly different compared to the nonCAM group with a CE angle of 21.0 degrees +/- 5.4 degrees vs. 23.7 degrees +/- 5.8 degrees (p = 0.050) and an acetabular hip index of 25.6 +/- 5.7 vs. 21.9 +/- 7.3 (p = 0.031), respectively. Furthermore, a crossing over sign was observed to be more common in the nonCAM group, which is contradictory to the current literature. For rotational alignment, no significant differences were observed. In dysplastic hips, the CAM-type FAI correlated to a lower CE angle and a higher acetabular hip index. In contrast to the current literature, no significant correlations to the torsional alignment or to crossing over signs were observed
Frontolimbic neural circuitry at 6 months predicts individual differences in joint attention at 9 months
Elucidating the neural basis of joint attention in infancy promises to yield important insights into the development of language and social cognition, and directly informs developmental models of autism. We describe a new method for evaluating responding to joint attention performance in infancy that highlights the 9- to 10-month period as a time interval of maximal individual differences. We then demonstrate that fractional anisotropy in the right uncinate fasciculus, a white matter fiber bundle connecting the amygdala to the ventral-medial prefrontal cortex and anterior temporal pole, measured in 6-month-olds predicts individual differences in responding to joint attention at 9 months of age. The white matter microstructure of the right uncinate was not related to receptive language ability at 9 months. These findings suggest that the development of core nonverbal social communication skills in infancy is largely supported by preceding developments within right lateralized frontotemporal brain systems
Fiber-Flux Diffusion Density for White Matter Tracts Analysis: Application to Mild Anomalies Localization in Contact Sports Players
We present the concept of fiber-flux density for locally quantifying white
matter (WM) fiber bundles. By combining scalar diffusivity measures (e.g.,
fractional anisotropy) with fiber-flux measurements, we define new local
descriptors called Fiber-Flux Diffusion Density (FFDD) vectors. Applying each
descriptor throughout fiber bundles allows along-tract coupling of a specific
diffusion measure with geometrical properties, such as fiber orientation and
coherence. A key step in the proposed framework is the construction of an FFDD
dissimilarity measure for sub-voxel alignment of fiber bundles, based on the
fast marching method (FMM). The obtained aligned WM tract-profiles enable
meaningful inter-subject comparisons and group-wise statistical analysis. We
demonstrate our method using two different datasets of contact sports players.
Along-tract pairwise comparison as well as group-wise analysis, with respect to
non-player healthy controls, reveal significant and spatially-consistent FFDD
anomalies. Comparing our method with along-tract FA analysis shows improved
sensitivity to subtle structural anomalies in football players over standard FA
measurements
Alpha B-crystallin protects retinal tissue during Staphylococcus aureus-induced endophthalmitis
Bacterial infections of the eye highlight a dilemma that is central to all immune-privileged sites. On the one hand, immune privilege limits inflammation to prevent bystander destruction of normal tissue and loss of vision. On the other hand, bacterial infections require a robust inflammatory response for rapid clearance of the pathogen. We demonstrate that the retina handles this dilemma, in part, by activation of a protective heat shock protein. During Staphylococcus aureus-induced endophthalmitis, the small heat shock protein αB-crystallin is upregulated in the retina and prevents apoptosis during immune clearance of the bacteria. In the absence of αB-crystallin, mice display increased retinal apoptosis and retinal damage. We found that S. aureus produces a protease capable of cleaving αB-crystallin to a form that coincides with increased retinal apoptosis and tissue destruction. We conclude that αB-crystallin is important in protecting sensitive retinal tissue during destructive inflammation that occurs during bacterial endophthalmitis
Frontolimbic neural circuitry at 6Â months predicts individual differences in joint attention at 9Â months
Elucidating the neural basis of joint attention in infancy promises to yield important insights into the development of language and social cognition, and directly informs developmental models of autism. We describe a new method for evaluating responding to joint attention performance in infancy that highlights the 9 to 10 month period as a time interval of maximal individual differences. We then demonstrate that fractional anisotropy in the right uncinate fasciculus, a white matter fiber bundle connecting the amygdala to the ventral-medial prefrontal cortex and anterior temporal pole, measured in 6 month-olds predicts individual differences in responding to joint attention at 9 months of age. The white matter microstructure of the right uncinate was not related to receptive language ability at 9 months. These findings suggest that the development of core nonverbal social communication skills in infancy is largely supported by preceding developments within right lateralized frontotemporal brain systems
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