Quantile Regression: On Inferences about the Slopes Corresponding to One, Two or Three Quantiles

The problem of testing hypotheses about the slope of a quantile regression line when the sample size is small is considered. A modified bootstrap method is suggested that is found to have certain advantages over the inverse rank method recommended by Koenker (1994). A method is suggested that simultaneously controls the probability of at least one Type I error when performing two or three tests corresponding to two or three specific quantiles. Using data from actual studies, it is illustrated that the new method can yield substantially shorter confidence intervals than the rank inverse method and, even with a large sample size, the choice of method can matter

Controlling Cattail Invasion in Sedge / Grass Meadows

As a result of water-level regulation, cattails have invaded sedge/grass meadow in all wetlands on Lake Ontario. Even with a change in water-level-regulation to a more natural hydrologic regime, restoration requires methods for active cattail management without the ability to manipulate water depths and without imperiling other vegetation. We conducted replicated studies at a wetland site with an active invasion front in zones of nearly mono-dominant cattail and transitional invasion. We tested various combinations of cutting cattail ramets when carbohydrate reserves were minimized, spraying cut stems with herbicide, slicing rhizomes to mimic tilling, and hand-wicking resprouted ramets with herbicide.We also collected companion environmental data. The most effective treatment in both zones was cutting during the period with reduced rhizome carbohydrates followed by handwicking resprouted ramets with herbicide in late summer, which allows the herbicide to be absorbed by the rhizomes. Two years of treatment provide the best results, reducing cattail stem counts and cover by more than 50%, but follow-up applications in ensuing years may be warranted to treat surviving cattails. Given the widespread problem of cattail invasion, these treatments may have broad application in wetlands where water levels cannot be manipulated

Reintegration Partnership Project: Summary of Key Findings and Recommendations

There are approximately 2.6 million men and women who have served in the U.S. military during the post-9/11 period and their transitions home after deployment often create a rollercoaster of mixed experiences. About 40 percent of the fighting and support services deployed to Iraq and Afghanistan are members of the National Guard and Reserve Forces who often return to civilian communities that are ill-prepared to accommodate their reintegration needs. This brief describes the Reintegration Partnership Project, which explored the transition process for California National Guard members and their families after Reintegration Skills Training (RST), an evidence-based problem-solving practice aimed at easing the challenges associated with transition from combat to civilian life. It also reports findings of a follow-up assessment of the reintegration experience for California National Guard members

The effects of dyad reading and text difficulty on third-graders’ reading achievement

This study replicated, with modifications, previous research of dyad reading using texts at various levels of difficulty (Morgan, 1997). The current project measured the effects of using above–grade-level texts on reading achievement and sought to determine the influences of dyad reading on both lead and assisted readers. Results indicate that weaker readers, using texts at two, three, and four grade levels above their instructional levels with the assistance of lead readers, outscored both proficient and less proficient students in the control group across multiple measures of reading achievement. However, the gains made by assisted readers were not significantly different relative to the various text levels. When all assessments were considered, assisted readers reading texts two grade levels above their instructional levels showed the most robust gains in oral reading fluency and comprehension. Lead readers also benefited from dyad reading and continued their respective reading developmental trajectories across measures

Aerial dissemination of Clostridium difficile spores

Background: Clostridium difficile-associated diarrhoea (CDAD) is a frequently occurring healthcare-associated infection, which is responsible for significant morbidity and mortality amongst elderly patients in healthcare facilities. Environmental contamination is known to play an important contributory role in the spread of CDAD and it is suspected that contamination might be occurring as a result of aerial dissemination of C. difficile spores. However previous studies have failed to isolate C. difficile from air in hospitals. In an attempt to clarify this issue we undertook a short controlled pilot study in an elderly care ward with the aim of culturing C. difficile from the air. Methods: In a survey undertaken during February (two days) 2006 and March (two days) 2007, air samples were collected using a portable cyclone sampler and surface samples collected using contact plates in a UK hospital. Sampling took place in a six bedded elderly care bay (Study) during February 2006 and in March 2007 both the study bay and a four bedded orthopaedic bay (Control). Particulate material from the air was collected in Ringer's solution, alcohol shocked and plated out in triplicate onto Brazier's CCEY agar without egg yolk, but supplemented with 5 mg/L of lysozyme. After incubation, the identity of isolates was confirmed by standard techniques. Ribotyping and REP-PCR fingerprinting were used to further characterise isolates. Results: On both days in February 2006, C. difficile was cultured from the air with 23 samples yielding the bacterium (mean counts 53 – 426 cfu/m3 of air). One representative isolate from each of these was characterized further. Of the 23 isolates, 22 were ribotype 001 and were indistinguishable on REP-PCR typing. C. difficile was not cultured from the air or surfaces of either hospital bay during the two days in March 2007. Conclusion: This pilot study produced clear evidence of sporadic aerial dissemination of spores of a clone of C. difficile, a finding which may help to explain why CDAD is so persistent within hospitals and difficult to eradicate. Although preliminary, the findings reinforce concerns that current C. difficile control measures may be inadequate and suggest that improved ward ventilation may help to reduce the spread of CDAD in healthcare facilities

Discriminative Stimulus Effects of Magnesium Chloride: Substitution Studies with Monoamine Uptake Inhibitors and N-Methyl-D-Aspartate Antagonists 1

ABSTRACT Previous studies suggest that magnesium chloride may have discriminative stimulus effects that partially overlap with those of noncompetitive N-methyl-D-aspartate antagonists as well as certain monoamine uptake inhibitors. In our study, rats were trained to discriminate 100 mg/kg magnesium chloride from saline and its discriminative stimulus effects were characterized with respect to N-methyl-D-aspartate receptor and monoamine transporter functions in substitution tests. The discriminative stimulus effects of magnesium chloride were acquired within a moderate number of training sessions and showed dose-related substitution after either subcutaneous (3-300 mg/kg) or intracerebroventricular (0.3-300 g) administration. The intracerebroventricular administration of magnesium chloride was over 4000 times more potent than its s.c. administration. The monoamine uptake inhibitors cocaine, GBR 12909, talsupram and citalopram fully substituted (Ն90% magnesium-appropriate responses) for magnesium chloride in the majority of subjects tested and the group averages reached a maximum of 72 to 82% responses on the magnesium-appropriate lever. Based on relative potency analysis, the rank order of potency of these four drugs for producing magnesium-appropriate responses was talsupram ϭ cocaine Ͼ citalopram ϭ GBR 12909. The N-methyl-D-aspartate receptor antagonists dizocilpine, phencyclidine and NPC 17742 engendered maximum group averages of 49 to 65% responses on the magnesium-appropriate lever. The results suggest that the centrally mediated discriminative stimulus effects of magnesium chloride may be more directly related to interactions with monoamine neurotransmitter functions than to N-methyl-D-aspartate receptor blockade

Long-term multisystemic efficacy of migalastat on Fabry-associated clinical events, including renal, cardiac and cerebrovascular outcomes

BACKGROUND: Fabry disease is a rare, multisystemic disorder caused by GLA gene variants that lead to alpha galactosidase A deficiency, resulting in accumulation of glycosphingolipids and cellular dysfunction. Fabry-associated clinical events (FACEs) cause significant morbidity and mortality, yet the long-term effect of Fabry therapies on FACE incidence remains unclear. METHODS: This posthoc analysis evaluated incidence of FACEs (as a composite outcome and separately for renal, cardiac and cerebrovascular events) in 97 enzyme replacement therapy (ERT)-naïve and ERT-experienced adults with Fabry disease and amenable GLA variants who were treated with migalastat for up to 8.6 years (median: 5 years) in Phase III clinical trials of migalastat. Associations between baseline characteristics and incidence of FACEs were also evaluated. RESULTS: During long-term migalastat treatment, 17 patients (17.5%) experienced 22 FACEs and there were no deaths. The incidence rate of FACEs was 48.3 events per 1000 patient-years overall. Numerically higher incidence rates were observed in men versus women, patients aged >40 years versus younger patients, ERT-naïve versus ERT-experienced patients and men with the classic phenotype versus men and women with all other phenotypes. There was no statistically significant difference in time to first FACE when analysed by patient sex, phenotype, prior treatment status or age. Lower baseline estimated glomerular filtration rate (eGFR) was associated with an increased risk of FACEs across patient populations. CONCLUSIONS: The overall incidence of FACEs for patients during long-term treatment with migalastat compared favourably with historic reports involving ERT. Lower baseline eGFR was a significant predictor of FACEs

Patterns and predictors of family environment among adolescents at high and low risk for familial bipolar disorder

Children's perceptions are important to understanding family environment in the bipolar disorder (BD) high-risk context. Our objectives were to empirically derive patterns of offspring-perceived family environment, and to test the association of family environment with maternal or paternal BD accounting for offspring BD and demographic characteristics. Participants aged 12–21 years (266 offspring of a parent with BD, 175 offspring of a parent with no psychiatric history) were recruited in the US and Australia. We modeled family environment using latent profile analysis based on offspring reports on the Conflict Behavior Questionnaire, Family Adaptability and Cohesion Evaluation Scales, and Home Environment Interview for Children. Parent diagnoses were based on the Diagnostic Interview for Genetic Studies and offspring diagnoses were based on the Schedule for Affective Disorders and Schizophrenia for School-Aged Children. Latent class regression was used to test associations of diagnosis and family environment. Two-thirds of all offspring perceived well-functioning family environment, characterized by nurturance, flexibility, and low conflict. Two ‘conflict classes’ perceived family environments low in flexibility and cohesion, with substantial separation based on high conflict with the father (High Paternal Conflict), or very high conflict and rigidity and low warmth with the mother (High Maternal Conflict). Maternal BD was associated with offspring perceiving High Maternal Conflict (OR 2.8, p = 0.025). Clinical care and psychosocial supports for mothers with BD should address family functioning, with attention to offspring perceptions of their wellbeing. More research is needed on the effect of paternal BD on offspring and family dynamics

An inclusive approach to raising standards in general practice: working with a 'community of practice' in Western Australia

<p>Abstract</p> <p>Background</p> <p>In this study we explored the challenges to establishing a community of practice (CoP) to address standards in general practice. We focused on the issue of improving referral letters which are the main form of communication between general practitioners (GPs) and specialists. There is evidence to suggest that the information relayed to specialists at the time of referral could be improved.</p> <p>Methods</p> <p>We aimed to develop a community of practice consisting of GPs in Western Australia to improve the quality of referral letters to six specialty clinics. Three phases included: establishing the CoP, monitoring the progress of the CoP and sustaining and managing the CoP. The CoP's activity centred on referral letters to each of six selected specialties. A local measure for the quality of the referral letters was developed from a survey of participants about specific items of history and weighted for their perceived importance in the referral letter. Referral letters by participants written before and after the benchmarking exercise were scored for quality based on the standards set by the CoP. Feedback to participants regarding the 'quality' of their individual referrals was provided by a nominated member of the CoP, including a comparison of before and after scores.</p> <p>Results</p> <p>15 GPs were recruited. Only five GPs submitted referral letters both before and after benchmarking. The five GPs that participated in both study phases submitted a total of 102 referral letters (53 before and 49 after). There was a 26 point (95% CI 11–41) improvement in the average scores of the second set of letters after taking clustering by speciality into account, indicating the quality of referral letters improved substantially after feedback.</p> <p>Conclusion</p> <p>There are many challenges to forming a CoP to focus on improving a specific issue in general practice. However we were able to demonstrate that those practitioners who participated in all aspects of the project substantially improved the quality of their referral letters. For recruitment it was important to work with a champion for the project from within the practice. The project took several months to complete therefore some GPs became disengaged. Some were very disappointed by their performance when compared to colleagues. This reaction may be an important motivation to change, however it needs to be sensitively handled if participants are not to become disillusioned or disheartened.</p