2,994 research outputs found

    The spell definition in ISO-15927 and its impact on the rain deposition on the building facade

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    Wind-driven rain (WDR) is one of the most important causes for water damage in buildings. Therefore, the first crucial step to assess the hygrothermal performance of the building envelope, is the appropriate estimation of the amount of rainwater striking the building's facade. ISO 15927 offers the annual average index-mainly to assess the moisture content of absorbent surfaces, and the spell index-more related to the likelihood of water penetration through joints. To calculate these indices, assumptions are made concerning the length of the period of 'no rain', called 'spell definition'. Obviously, the choice of this spell definition will characterise the WDR-amount. In this paper, WDR measurements of a 3-storey building in Vancouver, Canada are used to investigate how this spell definition affects the rain load. Different filter criteria are used to exclude errors due to measurement equipment. By means of the catch ratio as a dimensionless parameter, the results of the analysis for different spell definitions are compared to hourly and 5-min data. It is concluded that longer spell definitions result in lower catch ratios and an underestimation of the WDR load. Hourly data turns out to be a more conservative approach for WDR-assessment of this case study, but is able to represent the spread on the catch ratio most closely to the original 5min-dataset. (C) 2015 The Authors. Published by Elsevier Ltd

    Tracing Spasmodic Dysphonia: the source of Ludwig Traube’s priority

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    Objectives: Since the mid-20th century, one citation is given historical priority as the first description of Spasmodic Dysphonia (SD): Ludwig Traube’s 1871 case of the “spastic form of nervous hoarseness”. Our objective is to understand how this case serves as the foundation of understanding laryngeal movement disorders. Methods: The original German paper was located and translated. Bibliographical and bibliometric methods are used to determine the citation history of this original source over the past 140 years. Results: Although secondary citations in contemporary publications typically credit Traube for establishing the clinical entity SD, his case does not conform to currently accepted diagnostic features. Citation patterns indicate the source of Traube’s priority is publications by Arnold and Luchsinger, mid-20th century ENT clinician, particularly their influential 1965 textbook used to train US and UK clinicians on voice disorders for several generations. Conclusions: Sometimes secondary citations in medical literature lead to the inadvertent perpetuation of factual misrepresentation. The clinical picture of Traube’s original case does not represent what clinicians would recognize as SD today. The rich 19th century literature on voice disorders is a valuable resource for present day clinicians

    1-[6-(Hydroxy­meth­yl)-2-pyrid­yl]-3-(2,4,6-trimethyl­benz­yl)-1H-imidazol-3-ium bromide

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    In the title compound, C19H22N3O+·Br−, the imidazole ring is approximately coplanar with the pyridine ring [dihedral angle = 0.88 (13)°] and nearly perpendicular to the benzene ring [dihedral angle = 81.70 (13)°]. O—H⋯Br and C—H⋯Br hydrogen bonding helps to stabilize the crystal structure

    Anarchy in the UK: Detailed genetic analysis of worker reproduction in a naturally occurring British anarchistic honeybee, Apis mellifera, colony using DNA microsatellites

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    Anarchistic behaviour is a very rare phenotype of honeybee colonies. In an anarchistic colony, many workers’ sons are reared in the presence of the queen. Anarchy has previously been described in only two Australian colonies. Here we report on a first detailed genetic analysis of a British anarchistic colony. Male pupae were present in great abundance above the queen excluder, which was clearly indicative of extensive worker reproduction and is the hallmark of anarchy. Seventeen microsatellite loci were used to analyse these male pupae, allowing us to address whether all the males were indeed workers’ sons, and how many worker patrilines and individual workers produced them. In the sample, 95 of 96 of the males were definitely workers’ sons. Given that ≈ 1% of workers’ sons were genetically indistinguishable from queen’s sons, this suggests that workers do not move any queen-laid eggs between the part of the colony where the queen is present to the area above the queen excluder which the queen cannot enter. The colony had 16 patrilines, with an effective number of patrilines of 9.85. The 75 males that could be assigned with certainty to a patriline came from 7 patrilines, with an effective number of 4.21. They were the offspring of at least 19 workers. This is in contrast to the two previously studied Australian naturally occurring anarchist colonies, in which most of the workers’ sons were offspring of one patriline. The high number of patrilines producing males leads to a low mean relatedness between laying workers and males of the colony. We discuss the importance of studying such colonies in the understanding of worker policing and its evolution

    One-Dimensional Birth-Death Process and Delbr\"{u}ck-Gillespie Theory of Mesoscopic Nonlinear Chemical Reactions

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    As a mathematical theory for the stochasstic, nonlinear dynamics of individuals within a population, Delbr\"{u}ck-Gillespie process (DGP) n(t)ZNn(t)\in\mathbb{Z}^N, is a birth-death system with state-dependent rates which contain the system size VV as a natural parameter. For large VV, it is intimately related to an autonomous, nonlinear ordinary differential equation as well as a diffusion process. For nonlinear dynamical systems with multiple attractors, the quasi-stationary and stationary behavior of such a birth-death process can be underestood in terms of a separation of time scales by a TeαVT^*\sim e^{\alpha V} (α>0)(\alpha>0): a relatively fast, intra-basin diffusion for tTt\ll T^* and a much slower inter-basin Markov jump process for tTt\gg T^*. In the present paper for one-dimensional systems, we study both stationary behavior (t=t=\infty) in terms of invariant distribution pnss(V)p_n^{ss}(V), and finite time dynamics in terms of the mean first passsage time (MFPT) Tn1n2(V)T_{n_1\rightarrow n_2}(V). We obtain an asymptotic expression of MFPT in terms of the "stochastic potential" Φ(x,V)=(1/V)lnpxVss(V)\Phi(x,V)=-(1/V)\ln p^{ss}_{xV}(V). We show in general no continuous diffusion process can provide asymptotically accurate representations for both the MFPT and the pnss(V)p_n^{ss}(V) for a DGP. When n1n_1 and n2n_2 belong to two different basins of attraction, the MFPT yields the T(V)T^*(V) in terms of Φ(x,V)ϕ0(x)+(1/V)ϕ1(x)\Phi(x,V)\approx \phi_0(x)+(1/V)\phi_1(x). For systems with a saddle-node bifurcation and catastrophe, discontinuous "phase transition" emerges, which can be characterized by Φ(x,V)\Phi(x,V) in the limit of VV\rightarrow\infty. In terms of time scale separation, the relation between deterministic, local nonlinear bifurcations and stochastic global phase transition is discussed. The one-dimensional theory is a pedagogic first step toward a general theory of DGP.Comment: 32 pages, 3 figure

    Angry responses to infant challenges: parent, marital, and child genetic factors associated with harsh parenting

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    This study examined genetic and environmental influences on harsh parenting of 9-month-olds. We examined whether positive child-, parent-, and family-level characteristics were associated with harsh parenting in addition to negative characteristics. We were particularly interested in examining evocative gene-environment correlation (rGE) by testing the effect of birth parent temperament on adoptive parents’ harsh parenting. Additionally, we examined associations among adoptive parents’ own temperaments, their marital relationship quality, and harsh parenting. Adoptive fathers’ (but not adoptive mothers’) harsh parenting was inversely related to an index of birth mother positive temperament (reward dependence), indicating evocative rGE. Higher marital quality was associated with less harsh parenting, but only for adoptive fathers. Adoptive parents’ negative temperamental characteristics (harm avoidance) were related to hostile parenting. Findings suggest the importance of enhancing positive family characteristics in addition to mitigating negative characteristics, as well as engaging multiple levels of the family system to prevent harsh parenting. Children have the potential to evoke strong positive and negative affective responses from parents, which then influence and organize caregiving behavior (Dix, 1991). All young children demonstrate challenging behaviors, such as prolonged crying that may be difficult to soothe, uncooperativeness with bathing or dressing, or difficulty with eating or sleeping. The degree to which parental negative emotion is evoked by these challenges and expressed in interactions with children is often characterized as harsh or overreactive parenting. Harsh parenting is a function of a complex interplay of risk and protective factors that operate at multiple levels of the family system (i.e., characteristics of the parent, child, and family environment; Belsky, 1984; Boivin et al., 2005; DiLalla & Bishop, 1996; Neiderhiser et al., 2004, 2007; Towers, Spotts, & Neiderhiser, 2002). The long-term maladaptive developmental outcomes associated with harsh, negative parenting during infancy (Bayer, Ukoumunne, Mathers, Wake, Abdi, & Hiscock, 2012; Bradley & Corwyn, 2008; Lorber & Egeland, 2009) underscore the need for improved understanding of risk and protective factors associated with early harsh parenting. The current study aims to extend on the research on harsh parenting in infancy in two ways. First, although risk factors for early harsh parenting are well documented, we know little about factors that buffer parents from harsh parenting during infancy; this study examines independent and differential effects of positive and negative characteristics on harsh parenting. Second, although interest in child effects on parenting, including harsh parenting, has been present in the field for decades (Bell, 1979; Bell & Chapman, 1986; Rutter et al., 1997) we know very little about the degree to which the effects found in the literature truly reflect evocative effects of infants’ genetically influenced characteristics. The current study used an adoption design to test the hypothesis that genetically influenced temperamental characteristics of 9-month-olds would influence adoptive parents’ harsh parenting. Previous research has identified many correlates of harsh parenting, including negative characteristics of the parent (e.g., maternal depression; Lovejoy, Graczyk, O’Hare, & Neuman, 2000), family (e.g., marital hostility, Rhoades et al., 2011), and child (e.g., difficult temperament, Plomin, Loehlin & DeFries, 1985; poor regulation, Bridgett et al., 2009). Previous research has identified risk factors for harsh parenting, but very little is known about how positive parent, child, and family characteristics might mitigate it. For example, a positive marital relationship could buffer the impact of high levels of depressive symptoms on parenting, and thus have implications for prevention and intervention efforts. The current study examined positive and negative parent, child, and family factors in association with harsh parenting. A second emphasis centered on understanding the role of infants’ genetically influenced characteristics on harsh parenting. Much of the previous work on child effects on parenting has examined child temperament. In general, child positivity is related to positive parenting, while child negativity is related to negative parenting (Putnam, Sanson, & Rothbart, 2002; Wilson & Durbin, 2012). However, the general lack of genetically sensitive designs in this research makes it impossible to determine whether these associations exist because (1) harsh parenting leads to negative child characteristics, (2) specific child characteristics evoke harsh parenting (evocative gene-environment correlation, rGE; Plomin, Loehlin & DeFries, 1977; Scarr & McCartney, 1983) or (3) children and parents share genes that contribute to both parenting and temperament (passive gene-environment correlation). Therefore, genetically-sensitive research designs are needed to disentangle these influences to understand specific mechanisms underlying relations between child characteristics and parent behavior

    Effect of Elevated Intra-Abdominal Pressure on Portal Vein and Superior Mesenteric Artery Blood Flow in a Rat

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    Abstract Aim: Recent clinical experience suggests that minimal access portoenterostomy (the Kasai procedure) for biliary atresia leads to transplantation sooner, compared to the traditional open approach. It should be emphasized that elevated intra-abdominal pressure (IAP) may reduce hepatic and portal blood flow and thus may cause histologic liver damage. The aim of the present study was to evaluate the effects of IAP on blood flow in the portal vein (PV), compared to the superior mesenteric artery (SMA), and on the systemic mean arterial blood pressure (MABP). Materials and Methods: Male Sprague-Dawley rats were anesthetized with intraperitoneal ketamine (90 mg per kg) and xylasine (13 mg per kg). Polyethylene catheters (PE-50) were introduced into the right carotid artery for the measurement of MABP. After a midline laparotomy, the SMA and PV were isolated. Ultrasonic blood-flow probes were placed on the vessels for the continuous measurement of regional blood flow. Two large-caliber percutaneous peripheral intravenous catheters were introduced into the peritoneal cavity for inflation of air and for the measurement of IAP. The time course of MABP and SMA and PV flow as well as the relationship between IAP and SMA and PV flow were determined. Results: Although all three hemodynamic parameters decreased with the increase in the IAP, the most significant changes were observed in PV blood flow. IAP at 3 mm Hg resulted in a 26% decrease in PV flow (P < 0.05), a 19% decrease in SMA flow (P < 0.05), and an 11% decrease in MABP (P < 0.05). IAP at 6 mm Hg caused a two-fold decrease in PV flow (P < 0.05), a 30% decrease in SMA flow (P < 0.05), and a 19% decrease in MABP (P < 0.05). There were no changes in the time course of MABP and PV and SMA flow. PV and SMA flow returned to normal values immediately after abdominal deflation. Conclusions: Persistent IAP decreased MABP, SMA, and, especially, PV flow by 50%. We speculate that in biliary atresia patients with already present liver dysfunction, decrease in SMA flow and even a greater decrease in PV flow from increased IAP, which occurs during a laparoscopic Kasai procedure, may further compromise liver function. This may be one of the explanations for the progression to earlier transplantation in infants undergoing a laparoscopic Kasai procedure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78156/1/lap.2008.0145.supp.pd

    Five Easy Pieces: The Dynamics of Quarks in Strongly Coupled Plasmas

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    We revisit the analysis of the drag a massive quark experiences and the wake it creates at a temperature T while moving through a plasma using a gravity dual that captures the renormalisation group runnings in the dual gauge theory. Our gravity dual has a black hole and seven branes embedded via Ouyang embedding, but the geometry is a deformation of the usual conifold metric. In particular the gravity dual has squashed two spheres, and a small resolution at the IR. Using this background we show that the drag of a massive quark receives corrections that are proportional to powers of log T when compared with the drag computed using AdS/QCD correspondence. We use the perturbation produced by the quark strings to compute the wake and compare with the results obtained using AdS/QCD correspondence. We also study the shear viscosity with running couplings, analyze the viscosity to entropy ratio and compare the result with the known bound. In the presence of higher order curvature square corrections from the back-reactions of the embedded D7 branes, we argue the possibility of the entropy to viscosity bound being violated. Finally, we show that our set-up could in-principle allow us to study a family of gauge theories at the boundary by cutting off the dual geometry respectively at various points in the radial direction. All these gauge theories can have well defined UV completions, and more interestingly, we demonstrate that any thermodynamical quantities derived from these theories would be completely independent of the cut-off scale and only depend on the temperature at which we define these theories. Such a result would justify the holographic renormalisabilities of these theories which we, in turn, also demonstrate. We give physical interpretations of these results and compare them with more realistic scenarios.Comment: 130 pages, 12 eps figures, LaTex; v4: final version with corrected typos, numerous additional references and enlargement of some sections. The published version, that appears in Nucl. Phys. B, differs slightly in section 3 where there is more emphasis on holographic renormalisabilty and less on the wake, compared to this versio
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