Hospitality codes and social exchange theory : the Pashtunwali and tourism in Afghanistan

The Afghan people are shrouded in rumor, myth and superstition. Drawing upon insights from military personnel, intelligence operatives, journalists and others, this study uses Social Exchange Theory (SET) to frame our understanding of their underpinning cultural code, the Pashtunwali. The study contributes both theoretically and empirically: The nature of the Pashtunwali highlights that SET cannot adequately frame some cultural exchange practices and a hybrid framework for negotiated and reciprocal exchange is presented. Furthermore, contextually, this is the first study that explores a code of hospitality through a social exchange lens to explore potential tourism development. A framework exists upon which commercial activity can be built without altering beliefs, social dynamics or day to day pursuits. For commercial development to be successful, it must yield similar or greater levels of income to those that currently exist, more importantly, traditions of autonomy and self-dependence will affect employment and training within an emergent tourism industry

CBS domains form energy-sensing modules whose binding of adenosine ligands is disrupted by disease mutations

CBS domains are defined as sequence motifs that occur in several different proteins in all kingdoms of life. Although thought to be regulatory, their exact functions have been unknown. However, their importance was underlined by findings that mutations in conserved residues within them cause a variety of human hereditary diseases, including (with the gene mutated in parentheses): Wolff-Parkinson-White syndrome (γ2 subunit of AMP-activated protein kinase); retinitis pigmentosa (IMP dehydrogenase-1); congenital myotonia, idiopathic generalized epilepsy, hypercalciuric nephrolithiasis, and classic Bartter syndrome (CLC chloride channel family members); and homocystinuria (cystathionine β-synthase). AMP-activated protein kinase is a sensor of cellular energy status that is activated by AMP and inhibited by ATP, but the location of the regulatory nucleotide-binding sites (which are prime targets for drugs to treat obesity and diabetes) was not characterized. We now show that tandem pairs of CBS domains from AMP-activated protein kinase, IMP dehydrogenase-2, the chloride channel CLC2, and cystathionine β-synthase bind AMP, ATP, or S-adenosyl methionine,while mutations that cause hereditary diseases impair this binding. This shows that tandem pairs of CBS domains act, in most cases, as sensors of cellular energy status and, as such, represent a newly identified class of binding domain for adenosine derivatives

Prospective Identification of Malaria Parasite Genes under Balancing Selection

BACKGROUND: Endemic human pathogens are subject to strong immune selection, and interrogation of pathogen genome variation for signatures of balancing selection can identify important target antigens. Several major antigen genes in the malaria parasite Plasmodium falciparum have shown such signatures in polymorphism-versus-divergence indices (comparing with the chimpanzee parasite P. reichenowi), and in allele frequency based indices. METHODOLOGY/PRINCIPAL FINDINGS: To compare methods for prospective identification of genes under balancing selection, 26 additional genes known or predicted to encode surface-exposed proteins of the invasive blood stage merozoite were first sequenced from a panel of 14 independent P. falciparum cultured lines and P. reichenowi. Six genes at the positive extremes of one or both of the Hudson-Kreitman-Aguade (HKA) and McDonald-Kreitman (MK) indices were identified. Allele frequency based analysis was then performed on a Gambian P. falciparum population sample for these six genes and three others as controls. Tajima's D (TjD) index was most highly positive for the msp3/6-like PF10_0348 (TjD = 1.96) as well as the positive control ama1 antigen gene (TjD = 1.22). Across the genes there was a strong correlation between population TjD values and the relative HKA indices (whether derived from the population or the panel of cultured laboratory isolates), but no correlation with the MK indices. CONCLUSIONS/SIGNIFICANCE: Although few individual parasite genes show significant evidence of balancing selection, analysis of population genomic and comparative sequence data with the HKA and TjD indices should discriminate those that do, and thereby identify likely targets of immunity

The first NINDS/NIBIB consensus meeting to define neuropathological criteria for the diagnosis of chronic traumatic encephalopathy.

Chronic traumatic encephalopathy (CTE) is a neurodegeneration characterized by the abnormal accumulation of hyperphosphorylated tau protein within the brain. Like many other neurodegenerative conditions, at present, CTE can only be definitively diagnosed by post-mortem examination of brain tissue. As the first part of a series of consensus panels funded by the NINDS/NIBIB to define the neuropathological criteria for CTE, preliminary neuropathological criteria were used by 7 neuropathologists to blindly evaluate 25 cases of various tauopathies, including CTE, Alzheimer's disease, progressive supranuclear palsy, argyrophilic grain disease, corticobasal degeneration, primary age-related tauopathy, and parkinsonism dementia complex of Guam. The results demonstrated that there was good agreement among the neuropathologists who reviewed the cases (Cohen's kappa, 0.67) and even better agreement between reviewers and the diagnosis of CTE (Cohen's kappa, 0.78). Based on these results, the panel defined the pathognomonic lesion of CTE as an accumulation of abnormal hyperphosphorylated tau (p-tau) in neurons and astroglia distributed around small blood vessels at the depths of cortical sulci and in an irregular pattern. The group also defined supportive but non-specific p-tau-immunoreactive features of CTE as: pretangles and NFTs affecting superficial layers (layers II-III) of cerebral cortex; pretangles, NFTs or extracellular tangles in CA2 and pretangles and proximal dendritic swellings in CA4 of the hippocampus; neuronal and astrocytic aggregates in subcortical nuclei; thorn-shaped astrocytes at the glial limitans of the subpial and periventricular regions; and large grain-like and dot-like structures. Supportive non-p-tau pathologies include TDP-43 immunoreactive neuronal cytoplasmic inclusions and dot-like structures in the hippocampus, anteromedial temporal cortex and amygdala. The panel also recommended a minimum blocking and staining scheme for pathological evaluation and made recommendations for future study. This study provides the first step towards the development of validated neuropathological criteria for CTE and will pave the way towards future clinical and mechanistic studies

Acute tryptophan depletion Moja-De: a method to study central nervous serotonin function in children and adolescents

Serotonin (5-HT) is widely implicated as a key neurotransmitter relevant to a range of psychiatric disorders and psychological processes. The role of central nervous 5-HT function underlying these processes can be examined through serotonergic challenge methodologies. Acute tryptophan depletion (ATD) is a key challenge method whereby a diminished dietary intake of tryptophan—the amino acid precursor to brain 5-HT synthesis—results in temporary diminished central nervous 5-HT synthesis. While this particular methodology has been used in adult populations, it was only recently that modifications were made to enable the use of ATD in child and adolescent populations. Additionally, the Moja-De modification of the ATD challenge methodology has demonstrated benefits over other ATD techniques used previously. The aim of this protocol paper is to describe the ATD Moja-De methodology in detail, its benefits, as well as studies that have been conducted to validate the procedure in child and adolescent samples. The ATD Moja-De protocol provides a potential methodology for investigating the role of central nervous 5-HT via manipulation of brain tryptophan availability in human psychopathology from a developmental viewpoint

Objective determination of the extratropical transition of tropical cyclones in the Northern Hemisphere

Extratropical transition (ET) has eluded objective identification since the realisation of its existence in the 1970s. Recent advances in numerical, computational models have provided data of higher resolution than previously available. In conjunction with this, an objective characterisation of the structure of a storm has now become widely accepted in the literature. Here we present a method of combining these two advances to provide an objective method for defining ET. The approach involves applying K-means clustering to isolate different life-cycle stages of cyclones and then analysing the progression through these stages. This methodology is then tested by applying it to five recent years from the European Centre of Medium-Range Weather Forecasting operational analyses. It is found that this method is able to determine the general characteristics for ET in the Northern Hemisphere. Between 2008 and 2012, 54% (±7, 32 of 59) of Northern Hemisphere tropical storms are estimated to undergo ET. There is great variability across basins and time of year. To fully capture all the instances of ET is necessary to introduce and characterise multiple pathways through transition. Only one of the three transition types needed has been previously well-studied. A brief description of the alternate types of transitions is given, along with illustrative storms, to assist with further stud

Effects of resistance exercise, collagen ingestion and circulating oestrogen concentration on collagen synthesis in a female athlete: a case report.

We investigated the effects of resistance exercise (RE), hydrolysed collagen (HC) ingestion and circulating oestrogen concentration on collagen synthesis in a naturally menstruating female CrossFit athlete. In a double-blind, randomised cross-over design, the participant (36 years; height 1.61 m; mass 82.6 kg) consumed 0 or 30 g HC prior to performing back-squat RE when endogenous circulating oestrogen concentration was low (onset of menses, OM) and high (late follicular phase, LF) during two consecutive menstrual cycles. Ten 5-mL blood samples were collected during each of the four interventions to analyse concentrations of serum 17β-oestradiol, and biomarkers of type I collagen turnover, that is serum procollagen type I N-terminal propeptide (PINP, a biomarker of collagen synthesis) and plasma β-isomerised C-terminal telopeptide of type I collagen (β-CTX, a biomarker of collagen breakdown), as well as the serum concentration of 18 collagen amino acids. 17β-Oestradiol concentration was 5-fold higher at LF (891 ± 116 pmol L−1) than OM (180 ± 13 pmol L−1). The PINP concentration × time area under the curve (AUC) was higher in the 30 g HC OM intervention (201 μg L−1 h) than the 30 g HC LF (144 μg L−1 h), 0 g HC OM (151 μg L−1 h) and 0 g HC LF (122 μg L−1 h) interventions. β-CTX concentration decreased 1.4-fold from pre-RE to 6 h post-RE in all interventions. Thus, high circulating oestrogen concentration was associated with lower collagen synthesis following RE in this female athlete. Ingesting 30 g HC, however, augmented the collagen synthesis response at LF and particularly at OM. Highlights: What is the central question of this study? Does resistance exercise-induced collagen synthesis vary according to circulating oestrogen concentration in a naturally menstruating female athlete, and if so, does hydrolysed collagen ingestion have any impact? What is the main finding and its importance? Exercise-induced collagen synthesis was low when circulating oestrogen concentration was high and vice versa. However, ingesting 30 g hydrolysed collagen prior to exercise reduced the negative effect of oestrogen on collagen synthesis. As high circulating oestrogen has been associated with greater injury risk in females, supplementing exercise with hydrolysed collagen may help protect these tissues from injury