Semi-static hedging for certain Margrabe type options with barriers

It turns out that in the bivariate Black-Scholes economy Margrabe type options exhibit symmetry properties leading to semi-static hedges of rather general barrier options. Some of the results are extended to variants obtained by means of Brownian subordination. In order to increase the liquidity of the hedging instruments for certain currency options, the duality principle can be applied to set up hedges in a foreign market by using only European vanilla options sometimes along with a risk-less bond. Since the semi-static hedges in the Black-Scholes economy are exact, closed form valuation formulas for certain barrier options can be easily derived.Comment: 18 page

Some considerations for the communication of results of air pollution health effects tracking

Communicating effectively and efficiently on air quality and its health impacts is an important but difficult and complex task. It requires careful consideration of the audience one wants to reach, the messages one is trying to present, the venue through which the message will be delivered. The audience, context, technique, and content factors may affect how well it is heard and how appropriately it is interpreted. In this short paper, I describe many of these concerns and provide some suggestions for how best to address them. However, since every audience differs in goals, characteristics, and nature, what is most important is implementing an effective communications program. This program should include frequent two-way communication, repeated and on-going evaluation of how well the audience understands the messages, and consideration of how to improve the delivery

Anti-HIV-1 activity of cellulose acetate phthalate: Synergy with soluble CD4 and induction of "dead-end" gp41 six-helix bundles

BACKGROUND: Cellulose acetate phthalate (CAP), a promising candidate microbicide for prevention of sexual transmission of the human immunodeficiency virus type 1 (HIV-1) and other sexually transmitted disease (STD) pathogens, was shown to inactivate HIV-1 and to block the coreceptor binding site on the virus envelope glycoprotein gp120. It did not interfere with virus binding to CD4. Since CD4 is the primary cellular receptor for HIV-1, it was of interest to study CAP binding to HIV-1 complexes with soluble CD4 (sCD4) and its consequences, including changes in the conformation of the envelope glycoprotein gp41 within virus particles. METHODS: Enzyme-linked immunosorbent assays (ELISA) were used to study CAP binding to HIV-1-sCD4 complexes and to detect gp41 six-helix bundles accessible on virus particles using antibodies specific for the α-helical core domain of gp41. RESULTS: 1) Pretreatment of HIV-1 with sCD4 augments subsequent binding of CAP; 2) there is synergism between CAP and sCD4 for inhibition of HIV-1 infection; 3) treatment of HIV-1 with CAP induced the formation of gp41 six-helix bundles. CONCLUSIONS: CAP and sCD4 bind to distinct sites on HIV-1 IIIB and BaL virions and their simultaneous binding has profound effects on virus structure and infectivity. The formation of gp41 six-helical bundles, induced by CAP, is known to render the virus incompetent for fusion with target cells thus preventing infection

ADHD and brain anatomy:What do academic textbooks used in the Netherlands tell students?

Studies of brain size of children classified with ADHD appear to reveal smaller brains when compared to ‘normal’ children. Yet, what does this mean? Even with the use of rigorously screened case and control groups, these studies show only small, average group differences between children with and without an ADHD classification. However, academic textbooks used in the Netherlands often portray individual children with an ADHD classification as having a different, malfunctioning brain that necessitates medical intervention. This conceptualisation of ADHD might serve professional interests, but not necessarily the interests of children

Maladaptive behaviors are linked with inefficient sleep in individuals with developmental disabilities

The purpose of the current study was to assess the relations between nightly sleep patterns and the frequency of daily maladaptive behavior. Antecedent and consequential relations between sleep patterns and behavior were evaluated with time series analysis. Sleep efficiency and maladaptive behavior were determined for 20 female residents of an institutional care facility for adults with developmental disabilities. Daily maladaptive behavioral data and nightly sleep/awake logs were collected for 4 months for each participant. Efficient sleep patterns were significantly associated with lower frequencies of maladaptive behaviors. All lagged cross-correlations 8 days before and 8 days after an evening of sleep were significant. These findings suggested that inefficient sleep was associated with increased maladaptive behaviors and that the lagged associations reflected a chronic but not an acute linkage between sleep and behavior

Ballistic impacts on an anatomically correct synthetic skull with a surrogate skin/soft tissue layer

The aim of this work was to further develop a synthetic model of ballistic head injury by the addition of skin and soft tissue layers to an anatomically correct polyurethane skull filled with gelatine 10% by mass. Six head models were impacted with 7.62 x 39 mm full metal jacket mild steel core (FMJ MSC) bullets with a mean velocity of 652 m/s. The impact events were filmed with high-speed cameras. The models were imaged pre- and post-impact using computed tomography. The models were assessed post impact by two experienced Home Office pathologists and the images assessed by an experienced military radiologist. The findings were scored against real injuries. The entry wounds, exit wounds and fracture patterns were scored positively, but the synthetic skin and soft tissue layer was felt to be too extendable. Further work is ongoing to address this

Does socioeconomic status affect mortality subsequent to hospital admission for community acquired pneumonia among older persons?

BACKGROUND: Low socioeconomic status has been associated with increased morbidity and mortality for various health conditions. The purpose of this study was twofold: to examine the mortality experience of older persons admitted to hospital with community acquired pneumonia and to test the hypothesis of whether an association exists between socioeconomic status and mortality subsequent to hospital admission for community-acquired pneumonia. METHODS: A population based retrospective cohort study was conducted including all older persons patients admitted to Ontario hospitals with community acquired pneumonia between April 1995 and March 2001. The main outcome measures were 30 day and 1 year mortality subsequent to hospital admission for community-acquired pneumonia. RESULTS: Socioeconomic status for each patient was imputed from median neighbourhood income. Multivariate analyses were undertaken to adjust for age, sex, co-morbid illness, hospital and physician characteristics. The study sample consisted of 60,457 people. Increasing age, male gender and high co-morbidity increased the risk for mortality at 30 days and one year. Female gender and having a family physician as attending physician reduced mortality risk. The adjusted odds of death after 30-days for the quintiles compared to the lowest income quintile (quintile 1) were 1.02 (95% CI: 0.95–1.09) for quintile 2, 1.04 (95% CI: 0.97–1.12) for quintile 3, 1.01 (95% CI: 0.94–1.08) for quintile 4 and 1.03 (95% CI: 0.96–1.12) for the highest income quintile (quintile 5). For 1 year mortality, compared to the lowest income quintile the adjusted odds ratios were 1.01 (95% CI: 0.96–1.06) for quintile 2, 0.99 (95% CI: 0.94–1.04) for quintile 3, 0.99 (95% CI: 0.93–1.05) for quintile 4 and 1.03 (95% CI: 0.97–1.10) for the highest income quintile. CONCLUSION: Socioeconomic status is not associated with mortality in the older persons from community-acquired pneumonia in Ontario, Canada

Oral vitamin B(12 )therapy in the primary care setting: a qualitative and quantitative study of patient perspectives

BACKGROUND: Although oral replacement with high doses of vitamin B(12 )is both effective and safe for the treatment of B(12 )deficiency, little is known about patients' views concerning the acceptability and effectiveness of oral B(12). We investigated patient perspectives on switching from injection to oral B(12 )therapy. METHODS: This study involved a quantitative arm using questionnaires and a qualitative arm using semi-structured interviews, both to assess patient views on injection and oral therapy. Patients were also offered a six-month trial of oral B(12 )therapy. One hundred and thirty-three patients who receive regular B(12 )injections were included from three family practice units (two hospital-based academic clinics and one community health centre clinic) in Toronto. RESULTS: Seventy-three percent (63/86) of respondents were willing to try oral B(12). In a multivariate analysis, patient factors associated with a "willingness to switch" to oral B(12 )included being able to get to the clinic in less than 30 minutes (OR 9.3, 95% CI 2.2–40.0), and believing that frequent visits to the health care provider (OR 5.4, 95% CI 1.1–26.6) or the increased costs to the health care system (OR 16.7, 95% CI 1.5–184.2) were disadvantages of injection B(12). Fifty-five patients attempted oral therapy and 52 patients returned the final questionnaire. Of those who tried oral therapy, 76% (39/51) were satisfied and 71% (39/55) wished to permanently switch. Factors associated with permanently switching to oral therapy included believing that the frequent visits to the health care provider (OR 35.4, 95% CI 2.9–432.7) and travel/parking costs (OR 8.7, 95% CI 1.2–65.3) were disadvantages of injection B(12). Interview participants consistently cited convenience as an advantage of oral therapy. CONCLUSION: Switching patients from injection to oral B(12 )is both feasible and acceptable to patients. Oral B(12 )supplementation is well received largely due to increased convenience. Clinicians should offer oral B(12 )therapy to their patients who are currently receiving injections, and newly diagnosed B(12)-deficient patients who can tolerate and are compliant with oral medications should be offered oral supplementation

Topological data analysis reveals genotype-phenotype relationships in primary ciliary dyskinesia

Background: Primary ciliary dyskinesia (PCD) is a heterogeneous inherited disorder caused by mutations in approximately 50 cilia-related genes. PCD genotype-phenotype relationships have mostly arisen from small case series because existing statistical approaches to investigate relationships have been unsuitable for rare diseases. / Methods: We applied a topological data analysis (TDA) approach to investigate genotype-phenotype relationships in PCD. Data from separate training and validation cohorts included 396 genetically defined individuals carrying pathogenic variants in PCD genes. To develop the TDA models, twelve clinical and diagnostic variables were included. TDA-driven hypotheses were subsequently tested using traditional statistics. / Results: Disease severity at diagnosis measured by FEV1 z-score was (i) significantly worse in individuals with CCDC39 mutations compared to other gene mutations and (ii) better in those with DNAH11 mutations; the latter also reported less neonatal respiratory distress. Patients without neonatal respiratory distress had better preserved FEV1 at diagnosis. Individuals with DNAH5 mutations were phenotypically diverse. Cilia ultrastructure and beat pattern defects correlated closely to specific causative gene groups, confirming these tests can be used to support a genetic diagnosis. / Conclusions: This large scale multi-national study presents PCD as a syndrome with overlapping symptoms and variation in phenotype, according to genotype. TDA modelling confirmed genotype-phenotype relationships reported by smaller studies (e.g. FEV1 worse with CCDC39 mutations), and identified new relationships, including FEV1 preservation with DNAH11 mutations and diversity of severity with DNAH5 mutations

Factors associated with first- versus second generation long-acting antipsychotics prescribed un-der ordinary clinical practice in Italy.

Background For many years, long-acting intramuscular (LAI) antipsychotics have been prescribed predominantly to chronic and severe patients, as a last resort when other treatments failed. Recently, a broader and earlier use of LAIs, particularly second-generation LAIs, has been emphasized. To date, few studies attempted to frame how this change in prescribing took place in real-world practice. Therefore, this study aimed to describe the clinical features of patients prescribed with LAIs, and to explore possible prescribing differences between first- and second-generations LAIs under ordinary clinical practice in Italy. Methods The STAR Network \u201cDepot\u201d Study is an observational, longitudinal, multicenter study involving 35 centers in Italy. In the cross-sectional phase, patients prescribed with LAIs were consecutively recruited and assessed over a period of 12 months. Descriptive statistics and multivariable logistic regression analyses were employed. Results Of the 451 recruited patients, 61% were males. The level of social and working functioning was heterogeneous, as was the severity of disease. Seventy-two per cent of the patients had a diagnosis of the schizophrenia spectrum. Seventy per cent were prescribed with second-generation antipsychotic (SGA) LAIs (mostly paliperidone, aripiprazole and risperidone). Compared to first-generation antipsychotic (FGA) LAIs, patients prescribed with SGA LAIs were more often younger; employed; with a diagnosis of the schizophrenia spectrum or bipolar disorder; with higher levels of affective symptoms; with fewer LAI prescriptions in the past. Discussion LAIs' prescribing practices appear to be more flexible as compared to the past, although this change is mostly restricted to SGA LAI