Design of a Purlin System

This paper is concerned with the design of cold-formed steel structural members which span between the frames of a building and carry cladding which is usually either single- or double-skin profiled metal sheeting or a sandwich panel. The cladding is fIxed to these purlins or sheeting rails at regular intervals and the performance in service, and therefore the design, is strongly influenced by interaction with the sheeting. The connection between the purlins and the supporting structure also has a significant influence on performance so that, historically, the emphasis has tended to be on empirical methods of design rather than detailed calculations of the structural behaviour. In a previous paper[1], the fIrst author described the design of a purlin system, known as Multibeam Mark 2, based on a cold-formed steel Sigma profile. The alternative approaches to design were reviewed and a semi-empirical design procedure was described which resulted in safe but competitive load-span tables. This paper describes the design of Multibeam Mark 3. This involves a further evolution of the cross-section together with further improvement of the design procedure. The tendency is to continue to move away from reliance on testing and towards an approach which is much more orientated towards design by calculation, a trend which is becoming increasingly necessary in view of the proliferation of different cladding types, all offering different degrees of restraint to the purlin. It is shown that, in the present state-of-the-art, a design procedure based entirely on calculation, while taking into account such practical factors as restraint from alternative cladding systems and distortion and partial plasticity at internal supports, is now feasible. However, as the profession may not yet be ready for such a radical approach, the design procedure used for Multibeam Mark 3 is backed up by a comprehensive test programme

The effects of minimal tillage, contour cultivation and in-field vegetative barriers on soil erosion and phosphorus loss.

Runoff, sediment, total phosphorus and total dissolved phosphorus losses in overland flow were measured for two years on unbounded plots cropped with wheat and oats. Half of the field was cultivated with minimum tillage (shallow tillage with a tine cultivator) and half was conventionally ploughed. Within each cultivation treatment there were different treatment areas (TA). In the first year of the experiment, one TA was cultivated up and down the slope, one TA was cultivated on the contour, with a beetle bank acting as a vegetative barrier partway up the slope, and one had a mixed direction cultivation treatment, with cultivation and drilling conducted up and down the slope and all subsequent operations conducted on the contour. In the second year, this mixed treatment was replaced with contour cultivation. Results showed no significant reduction in runoff, sediment losses or total phosphorus losses from minimum tillage when compared to the conventional plough treatment, but there were increased losses of total dissolved phosphorus with minimum tillage. The mixed direction cultivation treatment increased surface runoff and losses of sediment and phosphorus. Increasing surface roughness with contour cultivation reduced surface runoff compared to up and down slope cultivation in both the plough and minimum tillage treatment areas, but this trend was not significant. Sediment and phosphorus losses in the contour cultivation treatment followed a very similar pattern to runoff. Combining contour cultivation with a vegetative barrier in the form of a beetle bank to reduce slope length resulted in a non-significant reduction in surface runoff, sediment and total phosphorus when compared to up and down-slope cultivation, but there was a clear trend towards reduced losses. However, the addition of a beetle bank did not provide a significant reduction in runoff, sediment losses or total phosphorus losses when compared to contour cultivation, suggesting only a marginal additional benefit. The economic implications for farmers of the different treatment options are investigated in order to assess their suitability for implementation at a field scale

Psychosexual development in men with congenital hypogonadotropic hypogonadism on long-term treatment: a mixed methods study.

INTRODUCTION: Congenital hypogonadotropic hypogonadism (CHH) is a rare, genetic, reproductive endocrine disorder characterized by absent puberty and infertility. Limited information is available on the psychosocial impact of CHH and psychosexual development in these patients. AIM: The aim of this study was to determine the impact of CHH on psychosexual development in men on long-term treatment. METHODS: A sequential mixed methods explanatory design was used. First, an online survey (quantitative) was used to quantify the frequency of psychosexual problems among CHH men. Second, patient focus groups (qualitative) were conducted to explore survey findings in detail and develop a working model to guide potential nursing and interdisciplinary interventions. MAIN OUTCOME MEASURES: Patient characteristics, frequency of body shame, difficulty with intimate relationships, and never having been sexually active were assessed. Additionally, we collected subjective patient-reported outcomes regarding the impact of CHH on psychological/emotional well-being, intimate relationships, and sexual activity. RESULTS: A total of 101 CHH men on long-term treatment (>1 year) were included for the analysis of the online survey (mean age 37 ± 11 years, range 19-66, median 36). Half (52/101, 51%) of the men had been seen at a specialized academic center and 37/101 (37%) reported having had fertility-inducing treatment. A high percentage of CHH men experience psychosexual problems including difficulty with intimate relationships (70%) and body image concerns/body shame (94/101, 93%), and the percentage of men never having been sexually active is five times the rate in a reference group (26% vs. 5.4%, P < 0.001). Focus groups revealed persisting body shame and low self-esteem despite long-term treatment that has lasting impact on psychosexual functioning. CONCLUSIONS: CHH men frequently experience psychosexual problems that pose barriers to intimate relationships and initiating sexual activity. These lingering effects cause significant distress and are not ameliorated by long-term treatment. Psychosexual assessment in CHH men with appropriate psychological support and treatment should be warranted in these patients. Dwyer AA, Quinton R, Pitteloud N, and Morin D. Psychosexual development in men with congenital hypogonadotropic hypogonadism on long-term treatment: A mixed methods study. Sex Med 2015;3:32-41

Identifying the unmet health needs of patients with congenital hypogonadotropic hypogonadism using a web-based needs assessment: implications for online interventions and peer-to-peer support.

BACKGROUND: Patients with rare diseases such as congenital hypogonadotropic hypogonadism (CHH) are dispersed, often challenged to find specialized care and face other health disparities. The internet has the potential to reach a wide audience of rare disease patients and can help connect patients and specialists. Therefore, this study aimed to: (i) determine if web-based platforms could be effectively used to conduct an online needs assessment of dispersed CHH patients; (ii) identify the unmet health and informational needs of CHH patients and (iii) assess patient acceptability regarding patient-centered, web-based interventions to bridge shortfalls in care. METHODS: A sequential mixed-methods design was used: first, an online survey was conducted to evaluate health promoting behavior and identify unmet health and informational needs of CHH men. Subsequently, patient focus groups were held to explore specific patient-identified targets for care and to examine the acceptability of possible online interventions. Descriptive statistics and thematic qualitative analyses were used. RESULTS: 105 male participants completed the online survey (mean age 37 ± 11, range 19-66 years) representing a spectrum of patients across a broad socioeconomic range and all but one subject had adequate healthcare literacy. The survey revealed periods of non-adherence to treatment (34/93, 37%) and gaps in healthcare (36/87, 41%) exceeding one year. Patient focus groups identified lasting psychological effects related to feelings of isolation, shame and body-image concerns. Survey respondents were active internet users, nearly all had sought CHH information online (101/105, 96%), and they rated the internet, healthcare providers, and online community as equally important CHH information sources. Focus group participants were overwhelmingly positive regarding online interventions/support with links to reach expert healthcare providers and for peer-to-peer support. CONCLUSION: The web-based needs assessment was an effective way to reach dispersed CHH patients. These individuals often have long gaps in care and struggle with the psychosocial sequelae of CHH. They are highly motivated internet users seeking information and tapping into online communities and are receptive to novel web-based interventions addressing their unmet needs

Breeding salmonids for feed efficiency in current fishmeal and future plant-based diet environments

The aquaculture industry is increasingly replacing fishmeal in feeds for carnivorous fish with soybean meal (SBM). This diet change presents a potential for genotype-environment (G × E) interactions. We tested whether current salmonid breeding programmes that evaluate and select within fishmeal diets also improve growth and efficiency on potential future SBM diets. A total of 1680 European whitefish from 70 families were reared with either fishmeal- or SBM-based diets in a split-family design. Individual daily gain (DG), daily feed intake (DFI) and feed efficiency (FE) were recorded. Traits displayed only weak G × E interactions as variances and heritabilities did not differ substantially between the diets, and cross-diet genetic correlations were near unity. In both diets, DFI exhibited moderate heritability and had very high genetic correlation with DG whereas FE had low heritability. Predicted genetic responses demonstrated that selection to increase DG and FE on the fishmeal diet lead to favourable responses on the SBM diet. Selection for FE based on an index including DG and DFI achieved at least double FE gain versus selection on DG alone. Therefore, current breeding programmes are improving the biological ability of salmonids to use novel plant-based diets, and aiding the aquaculture industry to reduce fishmeal use

Beyond hormone replacement: quality of life in women with congenital hypogonadotropic hypogonadism.

Little is known about how women with isolated GnRH deficiency cope with their condition. This study aimed to examine the health and informational needs of women with congenital hypogonadotropic hypogonadism (CHH) and evaluate if their experiences differ from women with more common forms of infertility. Cross-sectional, multiple methods study using web-based data collection to reach dispersed rare disease patients. A community-based participatory research framework was employed to develop an online survey and collect quantitative and qualitative data. Adult women diagnosed with CHH who had received at least one year of hormonal treatment completed the Morisky Medication Adherence Scale, Revised Illness Perception Questionnaire and Zung Self-Rating Depression Scale. Information on health care experiences, treatment outcomes and patient-reported challenges were also collected. Women (n = 55) were often diagnosed late (20.7 ± 7.4, range: 10-48 years) and 16/20 patients receiving fertility treatment conceived. Poor adherence was frequently observed (34/55) while more than half (27/49) reported a gap in treatment exceeding a year. Low adherence correlated with depressive symptoms (r = 0.3, P > 0.05). Negative illness perceptions were pervasive and 30/55 exhibited some depressive symptoms - significantly greater than women with common female factor infertility (P < 0.01). Symptoms were underappreciated by providers as only 15 of 55 patients had discussions about psychological services. Women identified isolation, need for information and finding expert care as challenges to living with CHH. Despite being a treatable form of female infertility, the presumable availability of treatment does not necessarily ensure adequate quality of life for women with isolated GnRH deficiency

Leptin and the leptin receptor : Molecular and genetic studies.

Leptin, a 16kDa protein, is secreted primarily by adipose tissue. Its effects are pleiotropic, with known roles in body mass regulation, haematopoiesis, immune function and reproduction.Studies of the leptin system in females were undertaken to complement existing animal and human studies. Serum leptin levels were found to increase in the luteal phase of the menstrual cycle raising the possibility of a role for leptin at the time of implantation. RT-PCR studies showed that leptin receptors were expressed in the human endometrium throughout the menstrual cycle. In these preliminary studies, these receptors appeared to be functional in response to leptin; increasing proliferation and decreasing TNF-a production in cultured endometrial cells. This implies that leptin has a local effect at the level of the endometrium.Many cytokines are bound to proteins in serum; a proportion of this binding can be attributed to a soluble cytokine receptor. Soluble receptors and binding proteins have a variety of roles, acting as scavengers, carriers, agonists and antagonists. In order to investigate this phenomenon in the leptin system, a radio-receptor assay was developed to measure leptin-binding activity (LBA). The leptin receptor has an extracellular domain that is common to all isoforms and therefore, LBA may also reflect the binding parameters of cell surface receptors. Serum leptin levels of LBA were found to be low at birth, high in early childhood, to fall steadily through puberty and remain at the post-pubertal levels throughout adult life. This suggests that leptin and LBA has an important role in the initiation of puberty. There was no significant variation in LBA during the menstrual cycle.Several single nucleotide polymorphisms (SNP) exist in the leptin receptor gene. Studies of two of these SNPs, GLN223ARG and LYS656ASN, present in the extracellular domain of the receptor were undertaken to assess if genetic changes are associated with differences in phenotype or effect ligand binding. Homozygosity of the G allele of GLN223ARG is associated with lower fat mass, BMI and leptin levels in postmenopausal Caucasian females. This polymorphism changes the binding characteristics of the receptor, with a higher LBA being associated with homozygosity of the G allele. This suggests that the actual binding of leptin to its receptor may be an important factor in the regulation of body weight and adiposity

Testing the early Late Ordovician cool-water hypothesis with oxygen isotopes from conodont apatite

© 2017 Cambridge University Press. Latest Sandbian to early Katian sequences across Laurentia\u27s epicontinental sea exhibit a transition from lithologies characterized as \u27warm-water\u27 carbonates to those characterized as \u27cool-water\u27carbonates. This shift occurs across the regionally recognized M4/M5 sequence stratigraphic boundary and has been attributed to climatic cooling and glaciation, basin reorganization and upwelling of open ocean water, and/or increased water turbidity and terrigenous input associated with the Taconic tectophase. Documentation of oxygen isotopic trends across the M4/M5 and through bracketing strata provides a potential means of distinguishing among these alternative scenarios; however, oxygen isotopic records generated to date have failed to settle the debate. This lack of resolution is because δ18O records are open to multiple interpretations and potentially confounding factors related to local environmental conditions have not been tested by examining the critical interval in multiple areas and different depositional settings. To begin to address this shortcoming, we present new species-specific and mixed assemblage conodont δ18O values in samples spanning the M4/M5 boundary from the Upper Mississippi Valley, Alabama, and Virginia. The new results are combined with previous studies, providing a record of δ18O variability across SE Laurentia. The combined dataset allows us to test for regional trends at a resolution not previously available. Our results document a ~1.5‰ decrease in values across Laurentia instead of increasing δ18O values across the M4/M5 as predicted in various \u27cool-water\u27 scenarios. In short, these results do not support a shift to \u27cool-water\u27 conditions as an explanation for changes in early Katian carbonates across the M4/M5

Gametogenesis in Malaria Parasites Is Mediated by the cGMP-Dependent Protein Kinase

Malaria parasite transmission requires differentiation of male and female gametocytes into gametes within a mosquito following a blood meal. A mosquito-derived molecule, xanthurenic acid (XA), can trigger gametogenesis, but the signalling events controlling this process in the human malaria parasite Plasmodium falciparum remain unknown. A role for cGMP was revealed by our observation that zaprinast (an inhibitor of phosphodiesterases that hydrolyse cGMP) stimulates gametogenesis in the absence of XA. Using cGMP-dependent protein kinase (PKG) inhibitors in conjunction with transgenic parasites expressing an inhibitor-insensitive mutant PKG enzyme, we demonstrate that PKG is essential for XA- and zaprinast-induced gametogenesis. Furthermore, we show that intracellular calcium (Ca2+) is required for differentiation and acts downstream of or in parallel with PKG activation. This work defines a key role for PKG in gametogenesis, elucidates the hierarchy of signalling events governing this process in P. falciparum, and demonstrates the feasibility of selective inhibition of a crucial regulator of the malaria parasite life cycle

Estimating the environmental impact of dairy cattle breeding programs through emission intensity.

A recently developed methodological approach for determining the greenhouse gas emissions impact of national breeding programs was applied to measure the effects of current and future breeding goals on the emission intensity (EI) of the Canadian dairy industry. Emission intensity is the ratio of greenhouse gas outputted in comparison to the product generated. Traits under investigation affected EI by either decreasing the direct emissions yield (i.e. increasing feed performance), changing herd structure (i.e. prolonging herd life) or through the dilution effect of increased production (i.e. increasing fat yield). The intensity value (IV) of each trait, defined as the change in emissions' intensity per unit change in each trait, was calculated for each of the investigated traits. The IV trend of these traits was compared for the current and prospective selection index, as well as for a system with and without quota (the supply management policy designed to prevent overproduction). The overall EI of the average genetic merit Canadian dairy herd per breeding female was 5.07 kg CO2eq/kg protein equivalent output. The annual reduction in EI due to the improvement of production traits was -0.027, -0.018 and -0.006 for fat, protein and milk other solids, respectively. The functional traits, herd life and mastitis resistance, had more modest effects (-0.008 and -0.001, respectively). These results are consistent with international studies that identified traits related to production, survival, health and fertility as having the largest impact on the environmental footprint of dairy cattle. Overall, the dairy industry is becoming more efficient by reducing its EI through selection of environmentally favorable traits, with a 1% annual reduction of EI in Canada