On the Sum of Fisher-Snedecor F Variates and its Application to Maximal-Ratio Combining

Capitalizing on the recently proposed Fisher-Snedecor F composite fading model, in this letter, we investigate the sum of independent but not identically distributed (i.n.i.d.) Fisher-Snedecor F variates. First, a novel closed-form expression is derived for the moment generating function of the instantaneous signal-to-noise ratio. Based on this, the corresponding probability density function and cumulative distribution function of the sum of i.n.i.d. Fisher- Snedecor F variates are derived, which are subsequently employed in the analysis of multiple branch maximal-ratio combining (MRC). Specifically, we investigate the impact of multipath and shadowed fading on the outage probability and outage capacity of MRC based receivers. In addition, we derive exact closed-form expressions for the average bit error rate of coherent binary modulation schemes followed by an asymptotic analysis which provides further insights into the effect of the system parameters on the overall performance. Importantly, it is shown that the effect of multipath fading on the system performance is more pronounced than that of shadowing.Comment: 5 pages, 3 figure

The role of Dark Matter interaction in galaxy clusters

We consider a toy model to analyze the consequences of dark matter interaction with a dark energy background on the overall rotation of galaxy clusters and the misalignment between their dark matter and baryon distributions when compared to {\Lambda}CDM predictions. The interaction parameters are found via a genetic algorithm search. The results obtained suggest that interaction is a basic phenomenon whose effects are detectable even in simple models of galactic dynamics.Comment: RevTeX 4.1, 5 pages, 3 figure

A nationwide cohort study of slipped capital femoral epiphysis

Objectives To describe the epidemiology of slipped capital femoral epiphysis (SCFE), to examine associations with childhood obesity and socioeconomic deprivation, and to explore factors associated with diagnostic delays. Design Historic cohort study using linked primary and secondary care data from the Clinical Practice Research Datalink and Hospital Episode Statistics. Setting All contacts with healthcare services, including emergency presentations, outpatient appointments, inpatient admissions and primary care visits, within the UK National Health Service. Patients All individuals <16 years old with a diagnosis of SCFE and whose electronic medical record was held by one of 650 primary care practices in the UK between 1990 and 2013. Main outcome measures Annual incidence, missed opportunities for diagnosis and diagnostic delay. Results Over the 23-year period the incidence remained constant at 4.8 (95% CI 4.4 to 5.2) cases per 100,000 0–16-year-olds. There was a strong association with socioeconomic deprivation. Predisease obesity was also strongly associated with SCFE; mean predisease z-score of body mass index was 1.43 (95% CI 1.20 to 1.68) compared with the UK reference mean. Diagnostic delays were common, with most children (75.4%) having multiple primary care contacts with relevant symptomatology, and those who presented with knee pain having significantly longer diagnostic delay (median 161 (IQR 27–278) days) than those with hip pain (20 (5–126)) or gait abnormalities (21 (7–72)). Conclusions SCFE has a strong association with both area-level socioeconomic deprivation and predisease obesity. The majority of patients with SCFE are initially misdiagnosed and those presenting with knee pain are particularly at risk

A qualitative study of clinicians’ experience of a clinical trial for displaced distal radius fractures

Aims: The aim of this study was to explore clinicians’ experience of a paediatric randomized controlled trial (RCT) comparing surgical reduction with non-surgical casting for displaced distal radius fractures. Methods: Overall, 22 staff from 15 hospitals who participated in the RCT took part in an interview. Interviews were informed by phenomenology and analyzed using thematic analysis. Results: Analysis of the findings identified the overarching theme of “overcoming obstacles”, which described the challenge of alleviating staff concerns about the use of non-surgical casting and recruiting families where there was treatment uncertainty. In order to embed and recruit to the Children’s Radius Acute Fracture Fixation Trial (CRAFFT), staff needed to fit the study within clinical practice, work together, negotiate treatment decisions, and support families. Conclusion: Recruiting families to this RCT was challenging because staff were uncertain about longer-term patient outcomes, and the difficulties were exacerbated by interdisciplinary tensions. Strong family and clinician beliefs, coupled with the complex nature of emergency departments and patient pathways that differed site-by-site, served as barriers to recruitment. Cementing a strong research culture, and exploring families’ treatment preferences, helped to overcome recruitment obstacles

Replication-deficient Adenoviral Vector for Gene Transfer Potentiates Airway Neurogenic Inflammation

Human trials for the treatment of cystic fibrosis lung disease with adenoviral vectors have been complicated by acute inflammatory reactions of unknown etiology. Because replicating respiratory viruses can potentiate tachykinin-mediated neurogenic inflammatory responses in airways, we studied whether the endotracheal administration of a replication-deficient adenoviral vector potentiated this response. The vector Ad5CMVLacZ was administered endotracheally to rats and the leakage of Evans blue dye was used to measure the capsaicin-induced neurogenic albumin extravasation. These studies show that neurogenic albumin extravasation is significantly potentiated in the airways of rats after administration of Ad5CMVLacZ. This inflammatory response can be blocked by selective antagonists of the substance Preceptor or by glucocorticoids. Therefore, (1) the acute airway inflammation observed in patients after exposure to adenoviral vectors may exhibit a neurogenic component, which can be blocked pharmacologically, and (2) preclinical adenoviral vector safety studies of other organs innervated by the tachykinin system, e.g., coronary arteries and gastrointestinal tract, should include assessment of neurogenic inflammation

Candidates for Balancing Selection in Leishmania donovani Complex Parasites

The Leishmania donovani species complex is the causative agent of visceral leishmaniasis, which cause 20–40,000 fatalities a year. Here, we conduct a screen for balancing selection in this species complex. We used 384 publicly available L. donovani and L. infantum genomes, and sequence 93 isolates of L. infantum from Brazil to describe the global diversity of this species complex. We identify five genetically distinct populations that are sufficiently represented by genomic data to search for signatures of selection. We find that signals of balancing selection are generally not shared between populations, consistent with transient adaptive events, rather than long-term balancing selection. We then apply multiple diversity metrics to identify candidate genes with robust signatures of balancing selection, identifying a curated set of 24 genes with robust signatures. These include zetatoxin, nodulin-like, and flagellum attachment proteins. This study highlights the extent of genetic divergence between L. donovani complex parasites and provides genes for further stud

Being recovered: a qualitative study of parents’ experience of their child’s recovery up to a year after a displaced distal radius fracture

Aims The aim of this study was to explore parents’ experience of their child’s recovery, and their thoughts about their decision to enrol their child in a randomized controlled trial (RCT) of surgery versus non-surgical casting for a displaced distal radius fracture. Methods A total of 20 parents of children from 13 hospitals participating in the RCT took part in an interview five to 11 months after injury. Interviews were informed by phenomenology and analyzed using thematic analysis. Results Analysis of the findings identified the theme “being recovered”, which conveyed: 1) parents’ acceptance and belief that their child received the best treatment for them; 2) their memory of the psychological impact of the injury for their child; and 3) their pride in how their child coped with their cast and returned to activities. The process of recovery was underpinned by three elements of experience: accepting the treatment, supporting their child through challenges during recovery, and appreciating their child’s resilience. These findings extend our framework that highlights parents’ desire to protect their child during early recovery from injury, by making the right decision, worrying about recovery, and comforting their child. Conclusion By one year after injury, parents in both treatment groups considered their child “recovered”. They had overcome early concerns about healing, the appearance of the wrist, and coping after cast removal. Greater educational support for families during recovery would enable parents and their child to cope with the uncertainty of recovery, particularly addressing the loss of confidence, worry about reinjury, and the appearance of their wrist

An integrated approach to assess the sublethal effects of colloidal gold nanorods in tadpoles of Xenopus laevis

Gold nanorods (AuNR) have been explored for many applications, including innovative nanomedicines, which also might contribute to its increase in the environment, namely due to inadequate disposable of wastes into aquatic environments. Early-life stages of amphibians are usually aquatic and sensitive to chemical contamination. Accordingly, this study aimed to determine the sublethal effects of CTAB functionalized AuNR on Xenopus laevis tadpoles. As such, tadpoles were exposed to serial concentrations of AuNR for 72 h. A reduction in the rate of feeding (EC50 = 4 μg.L-1), snout to vent growth (EC50 = 5 μg.L-1) and weight gain (EC50 = 6 μg.L-1), was observed for AuNR-exposed tadpoles. Also, tadpoles actively avoided concentrations ≥ 4 μg.L-1 of AuNR, after 12 h of exposure. At the biochemical level, AuNR caused impairments in antioxidant and nervous system related enzymes. Exposure to CTAB alone caused a high mortality. Results indicated that CTAB functionalized AuNR may induce several sublethal effects that may compromise the organism's fitness. Avoidance behavior (which corresponds to the disappearance of organisms, thus, similar to their death), observed at concentrations matching those inducing sublethal effects, suggest that it should be considered in the risk assessment for amphibians.publishe