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Recent experiments on thin films flowing down a vertical fibre with varying nozzle diameters present a wealth of new dynamics that illustrate the need for more advanced theory. We present a detailed analysis using a full lubrication model that includes slip boundary conditions, nonlinear curvature terms and a film stabilization term. This study brings to focus the presence of a stable liquid layer playing an important role in the full dynamics. We propose a combination of these physical effects to explain the observed velocity and stability of travelling droplets in the experiments and their transition to isolated droplets. This is also supported by stability analysis of the travelling wave solution of the model.
The hypothalamic–pituitary–adrenal axis (HPAA) plays a critical role in the functioning of all other biological systems. Thus, studying how the environment may influence its ontogeny is paramount to understanding developmental origins of health and disease. The early post-conceptional (EPC) period could be particularly important for the HPAA as the effects of exposures on organisms’ first cells can be transmitted through all cell lineages. We evaluate putative relationships between EPC maternal cortisol levels, a marker of physiologic stress, and their children’s pre-pubertal HPAA activity (n=22 dyads). Maternal first-morning urinary (FMU) cortisol, collected every-other-day during the first 8 weeks post-conception, was associated with children’s FMU cortisol collected daily around the start of the school year, a non-experimental challenge, as well as salivary cortisol responses to an experimental challenge (all Ps<0.05), with some sex-related differences. We investigated whether epigenetic mechanisms statistically mediated these links and, therefore, could provide cues as to possible biological pathways involved. EPC cortisol was associated with >5% change in children’s buccal epithelial cells’ DNA methylation for 867 sites, while children’s HPAA activity was associated with five CpG sites. Yet, no CpG sites were related to both, EPC cortisol and children’s HPAA activity. Thus, these epigenetic modifications did not statistically mediate the observed physiological links. Larger, prospective peri-conceptional cohort studies including frequent bio-specimen collection from mothers and children will be required to replicate our analyses and, if our results are confirmed, identify biological mechanisms mediating the statistical links observed between maternal EPC cortisol and children’s HPAA activity.
The oriental fruit fly Bactrocera dorsalis (Hendel) is a destructive insect pest of a wide range of fruit crops. Commensal bacteria play a very important part in the development, reproduction, and fitness of their host fruit fly. Uncovering the function of gut bacteria has become a worldwide quest. Using antibiotics to remove gut bacteria is a common method to investigate gut bacteria function. In the present study, three types of antibiotics (tetracycline, ampicillin, and streptomycin), each with four different concentrations, were used to test their effect on the gut bacteria diversity of laboratory-reared B. dorsalis. Combined antibiotics can change bacteria diversity, including cultivable and uncultivable bacteria, for both male and female adult flies. Secondary bacteria became the dominant population in female and male adult flies with the decrease in normally predominant bacteria. However, in larvae, only the predominant bacteria decreased, the bacteria diversity did not change a lot, likely because of the short acting time of the antibiotics. The bacteria diversity did not differ among fruit fly treatments with antibiotics of different concentrations. This study showed the dynamic changes of gut bacterial diversity in antibiotics-treated flies, and provides a foundation for research on the function of gut bacteria of the oriental fruit fly.
As a first step towards understanding the distribution of swimming micro-organisms in flowing shallow water containing vegetation, we formulate a continuum model for dilute suspensions in horizontal shear flow, with a maximum Reynolds number of 100, past a single, rigid, vertical, circular cylinder that extends from a flat horizontal bed and penetrates the free water surface. A numerical platform was developed to solve this problem, in four stages: first, a scheme for computation of the flow field; second, a solver for the Fokker–Planck equation governing the probability distribution of the swimming direction of gyrotactic cells under the combined action of gravity, ambient vorticity and rotational diffusion; third, the construction of a database for the mean swimming velocity and the translational diffusivity tensor as functions of the three vorticity components, using parameters appropriate for the swimming alga, Chlamydomonas nivalis; fourth, a solver for the three-dimensional concentration distribution of the gyrotactic micro-organisms. Upstream of the cylinder, the cells are confined to a vertical strip of width equal to the cylinder diameter, which enables us to visualise mixing in the wake. The flow downstream of the cylinder is divided into three zones: parallel vortex shedding in the top zone near the water surface, oblique vortex shedding in the middle zone and quasi-steady flow in the bottom zone. Secondary (vertical) flow occurs just upstream and downstream of the cylinder. Frequency spectra of the velocity components in the wake of the cylinder show two dominant frequencies of vortex shedding, in the parallel- and oblique-shedding zones respectively, together with a low frequency, equal to the difference between those two frequencies, that corresponds to a beating modulation. The concentration distribution is calculated for both active particles and passive, non-swimming, particles for comparison. The concentration distribution is very similar for both active and passive particles, except near the top surface, where upswimming causes the concentration of active particles to reach values greater than in the upstream strip, and in a thin boundary layer on the downstream surface of the cylinder, where a high concentration of active particles occurs as a result of radial swimming.
Some fire ants of the genus Solenopsis have become invasive species in the southern United States displacing native species by competition. Although the displacement pattern seems clear, the mechanisms underlying competitive advantage remain unclear. The ability of ant workers to produce relatively larger amount of alarm pheromone may correspond to relative greater fitness among sympatric fire ant species. Here we report on quantitative intra-specific (i.e. inter-caste) and inter-specific differences of alarm pheromone component, 2-ethyl-3,6-dimethylpyrazine (2E36DMP), for several fire ant species. The alarm pheromone component was extracted by soaking ants in hexane for 48 h and subsequently quantified by gas chromatography-mass spectrometry at single ion monitoring mode. Solenopsis invicta workers had more 2E36DMP than male or female alates by relative weight; individual workers, however, contained significantly less pyrazine. We thus believe that alarm pheromones may serve additional roles in alates. Workers of Solenopsis richteri, S. invicta, and hybrid (S. richteri × S. invicta) had significantly more 2E36DMP than a native fire ant species, Solenopsis geminata. The hybrid fire ant had significantly less 2E36DMP than the two parent species, S. richteri and S. invicta. It seems likely that higher alarm pheromone content may have favored invasion success of exotic fire ants over native species. We discuss the potential role of inter-specific variation in pyrazine content for the relationship between the observed shifts in the spatial distributions of the three exotic fire ant species in southern United States and the displacement of native fire ant species.
OBJECTIVES/SPECIFIC AIMS: Knowing how to deliver culturally responsive care is of increasing importance as the nation’s patient population diversifies. However, unless cultural competence is taught with an emphasis on self-awareness (Wear, 2007) and critical consciousness (Kumagai and Lypson, 2009) learners find this education ineffective (Beagan, 2003). This study examines how physicians perceive their own social identities (eg, race, socio-economic status, gender, sexual orientation, religion, years of experience) and how these self-perceptions influence physician’s understandings of how to practice culturally responsive care. METHODS/STUDY POPULATION: This exploratory study took place at a university in the Intermountain West. We employed a qualitative case study method to investigate how academic physicians think about their identities and approaches to clinical care and research through interviews and observations. In total, 25 participants were enrolled in our study, with efforts to recruit a diverse sample with respect to gender and race as well as years of experience and specialty. Transcriptions of interviews and observations were coded using grounded theory. One major code that emerged was defining experiences: instances where physicians reflected on both personal and professional life encounters that have influenced how they think about themselves, how they understand an aspect of their identity, or why this identity matters. RESULTS/ANTICIPATED RESULTS: Two main themes emerged from an analysis of the codes that show how physicians think about their identities and their approaches to practice. (1) Physicians with nondominant identities (women, non-White) could more easily explain what these identities mean to them than those with dominant identities (men, White). For example, women in medicine had much to say about being a woman in medicine, but men had barely anything to say about being a man in medicine. (2) There was a positive trend between the number of defining experiences a physician encountered in life and the number of connections they made between their identities and the manner in which they practiced, both clinically and academically. It appeared that physicians who have few defining experiences made few connections between identity and practice, those with a moderate number of experiences made a moderate number of connections, and those with many experiences made many connections. Physicians who mentioned having many defining experiences were more likely to be able to articulate how those experiences were incorporated into their approaches to patient care. DISCUSSION/SIGNIFICANCE OF IMPACT: (1) According to literature in multicultural education, those with dominant identities do not think about their identities because they do not have to (Johnson, 2001). One privilege of being part of the majority is not having to think about life from a minority perspective. This helps to explain why women and non-White physicians in this study had more anecdotes to share about these identities—because they have had defining experiences that prompt reflection on these identities. (2) We propose that struggles and conflict are what compel physicians to reflect on their practice (Eva et al., 2012). Our findings suggest that physicians are more prepared to apply what they have learned from their own identity struggles in delivering culturally responsive care when they have had more opportunities to reflect on these identities and situations. Findings from this study have implications for transforming approaches to medical education. We suggest that medical education should provide learners with the opportunity to reflect on their life experience, and that providers may need explicit instruction on how to make connections between their experiences and their practice.
The ultimate goal of poultry hatching is to increase the hatching rate and to produce healthy hatched birds. In the incubation process, temperature is the most important factor for the egg hatching rate, the growth performance and offspring phenotype. This not only affects the early development of the offspring, but also has a continued influence on the physical characteristics of the birds, such as final body weight and meat quality. This article reviews the importance of incubation temperature on offspring phenotype, sex differentiation, organism immunity and the development of muscle fibre in poultry.
Disruptions with runaway electron generation have been deliberately induced by injection of argon using a disruption mitigation valve. A second disruption mitigation valve has been utilised to inject varying amounts of helium after a short time delay. No generation of runaway electrons has been observed when more than a critical amount of helium has been injected no later than 5 ms after the triggering of the first valve. The required amount of helium for suppression of runaway electron generation is up to one order of magnitude lower than the critical density according to Connor & Hastie (1975) and Rosenbluth & Putvinski (1997).
Based on the analysis of data from the numerous dedicated experiments on plasma disruptions in the TEXTOR tokamak the mechanisms of the formation of runaway electron (RE) beams and their losses are proposed. The plasma disruption is caused by a strong stochastic magnetic field formed due to nonlinearly excited low-mode-number magneto-hydro-dynamics (MHD) modes. It is hypothesized that the RE beam is formed in the central plasma region confined by an intact magnetic surface due to the acceleration of electrons by the inductive toroidal electric field. In the case of plasmas with the safety factor
the most stable RE beams are formed by the outermost intact magnetic surface located between the magnetic surface
and the closest low-order rational surface
. The thermal quench (TQ) time caused by the fast electron transport in a stochastic magnetic field is calculated using the collisional transport model. The current quench (CQ) stage is due to the particle transport in a stochastic magnetic field. The RE beam current is modelled as a sum of a toroidally symmetric part and a small-amplitude helical current with a predominant
component. The REs are lost due to two effects: (i) by outward drift of electrons in a toroidal electric field until they touch the wall and (ii) by the formation of a stochastic layer of REs at the beam edge. Such a stochastic layer for high-energy REs is formed in the presence of the
MHD mode. It has a mixed topological structure with a stochastic region open to the wall. The effect of external resonant magnetic perturbations on RE loss is discussed. A possible cause of the sudden MHD signals accompanied by RE bursts is explained by the redistribution of runaway current during the resonant interaction of high-energetic electron orbits with the
In the near future, the inactivated enterovirus 71 (EV71) vaccine is expected to become available on the market in China. Since EV71 is a major cause of hand, foot and mouth disease (HFMD), the vaccine is expected to significantly reduce the number of cases, as well as the detrimental economic effect of the disease. However, for a national vaccination strategy to be developed, policy-makers need more information on the socioeconomic burden of EV71 HFMD infection. Based on the 2011 population data, we estimated the clinical and economic effect of EV71 HFMD infection in children aged 0–9 years in Shanghai, China. The annual cost related to HFMD is >US$7.66 million for a population of 1·42 million children aged 0–9 years with an average cost of US$208.2/case. The extrapolated cost for EV71 HFMD infection was US$3.53 million, comprising 46·1% of the overall cost associated with HFMD. Around 97% of all of the HFMD-related expenses were paid for by the families creating a considerable economic burden. Our findings could provide the necessary recommendations on the most effective national EV71 vaccine implementation, as well as a baseline data for assessing the cost-effectiveness of the vaccine in China.
Experimental evidence supporting the theory of hot tail runaway electron (RE) generation has been identified in TEXTOR disruptions. With higher temperature, more REs are generated during the thermal quench. Increasing the RE generation by increasing the temperature, an obvious RE plateau is observed even with low toroidal magnetic field (1.7 T). These results explain the previously found electron density threshold for RE generation.
The mealybug species Phenacoccus solenopsis (P. solenopsis) has caused much agricultural damage since its recent invasion in China. However, the source of this invasion remains unclear. This study uses molecular methods to clarify the relationships among different population of P. solenopsis from China, USA, Pakistan, India, and Vietnam to determine the geographic origin of the introduction of this species into China. P. solenopsis samples were collected from 25 different locations in three provinces of Southern China. Samples from the USA, Pakistan, and Vietnam were also obtained. Parts of the mitochondrial genes for cytochrome oxidase I (COI) were sequenced for each sample. Homologous DNA sequences of the samples from the USA and India were downloaded from Gen Bank. Two haplotypes were found in China. The first was from most samples from the Guangdong, Guangxi, and Hainan populations in the China and Pakistan groups, and the second from a few samples from the Guangdong, Guangxi, Hainan populations in the China, Pakistan, India, and Vietnam groups. As shown in the maximum likelihood of trees constructed using the COI sequences, these samples belonged to two clades. Phylogenetic analysis suggested that most P. solenopsis mealybugs in Southern China are probably closely related to populations in Pakistan. The variation, relationship, expansion, and probable geographic origin of P. solenopsis mealybugs in Southern China are also discussed.
Genetic association studies of the cytokine interleukin-10 (IL-10) and sepsis have provided inconsistent results. This work attempts to further quantitatively assess the association of three widely evaluated polymorphisms of IL-10 (−592C/A, −819C/T, −1082A/G) with sepsis susceptibility through a meta-analysis. A search of Pubmed, Web of Science and EMBASE databases was performed. Overall, the three polymorphisms have no strong association with sepsis risk. Subgroup analysis by ethnicity showed there was association between sepsis susceptibility with −592C/A in Caucasians (A vs. C: OR 0·78, 95% CI 0·62–1·00, P = 0·05; AA + CA vs. CC: OR 0·75, 95% CI 0·56–1·00, P = 0·05), and with −1082A/G in Asians (G vs. A: OR 1·41, 95% CI 1·04–1·91, P = 0·03; GG + AG vs. AA: OR 2·11, 95% CI 1·07–4·16, P = 0·03). This meta-analysis suggests that −592C/A and −1082A/G polymorphisms are associated with sepsis susceptibility in Caucasian, and Asian populations, respectively.
This study aimed to investigate the validity and feasibility of cervical oesophagostomy as a treatment for patients with severe dysphagia after radiotherapy for nasopharyngeal carcinoma.
The study retrospectively analysed the clinical data, symptoms, physical signs, treatment and outcomes of 12 patients treated with cervical oesophagostomy for severe dysphagia after radiotherapy for nasopharyngeal carcinoma, from 2006 to 2010.
In all 12 cases, the oesophageal stoma remained stable, without any complications such as pharyngeal fistula or inflammation. No oesophageal stricture or granuloma growth was observed. All patients reported significant improvement in their nutritional status and quality of life after the oesophagostomy surgery.
Cervical oesophagostomy is a valid and feasible method of treating severe dysphagia following radiotherapy for nasopharyngeal carcinoma. Oesophagostomy shows specific advantages over nasogastric tubing, gastrostomy and jejunostomy. Patients' nutrition and quality of life can be improved significantly if cervical oesophagostomy is executed in a timely fashion, especially in cases with severe trismus and multiple radiation-induced cranial nerve palsies unresponsive to rehabilitation.
Several studies have evaluated the association between mannose-binding lectin (MBL) polymorphisms and sepsis. However, the results are inconclusive and conflicting. To better understand the roles of MBL polymorphisms in sepsis, we conducted a comprehensive meta-analysis. All relevant studies were searched from PubMed, EMBASE and Web of Knowledge databases, with the last report up to 7 May 2013. Twenty-nine studies addressing four MBL polymorphisms (–550G/C, –221G/C, structure variant A/O, Gly54Asp) were analysed for susceptibility to sepsis and one study for sepsis-related mortality. Overall, significant associations between structure variant A/O and susceptibility to sepsis were observed for AO + OO vs. AA [odds ratio (OR) 1·27, 95% confidence interval (CI) 1·05–1·52, P = 0·01] and O vs. A (OR 1·19, 95% CI 1·02–1·40, P = 0·03). In subgroup analysis based on age group, increased risk was found in the paediatric group in the dominant model (OR 1·72, 95% CI 1·16–2·56, P = 0·007). Moreover, there was a slight association between the +54A/B polymorphism and susceptibility to sepsis in Caucasians (recessive model: OR 10·64, 95% CI 1·24–91·65, P = 0·03). However, no association was observed for –550G/C and –221G/C polymorphisms both overall and in subgroup analysis. For sepsis-related mortality, only one study suggested AO/OO was associated with in-hospital mortality in pneumococcal sepsis patients after controlling for confounding variables. Our meta-analysis indicated that MBL structure variants might be associated with susceptibility to sepsis but further studies with a large sample size should be conducted to confirm these findings.
Most knowledge regarding the effects of antidepressant drugs is at the receptor level, distal from the nervous system effects that mediate their clinical efficacy. Using functional magnetic resonance imaging (fMRI), this study investigated the effects of escitalopram, a selective serotonin reuptake inhibitor (SSRI), on resting-state brain function in patients with major depressive disorder (MDD).
Fourteen first-episode drug-naive MDD patients completed two fMRI scans before and after 8 weeks of escitalopram therapy. Scans were also acquired in 14 matched healthy subjects. Data were analyzed using the regional homogeneity (ReHo) approach.
Compared to controls, MDD patients before treatment demonstrated decreased ReHo in the frontal (right superior frontal gyrus), temporal (left middle and right inferior temporal gyri), parietal (right precuneus) and occipital (left superior occipital gyrus and right cuneus) cortices, and increased ReHo in the left dorsal medial prefrontal gyrus and left anterior lobe of the cerebellum. Compared to the unmedicated state, ReHo in the patients after treatment was decreased in the left dorsal medial prefrontal gyrus, the right insula and the bilateral thalamus, and increased in the right superior frontal gyrus. Compared to controls, patients after treatment displayed a ReHo decrease in the right precuneus and a ReHo increase in the left anterior lobe of the cerebellum.
Successful treatment with escitalopram may be associated with modulation of resting-state brain activity in regions within the fronto-limbic circuit. This study provides new insight into the effects of antidepressants on functional brain systems in MDD.
A system combining photovoltaic (PV) and solar thermal approaches is designed to convert solar energy to electricity with high efficiency across the full solar spectrum. Concentrated solar spectrum is split into two parts: PV and thermal. The PV part of the spectrum is further split into several subbands directed to bandgap appropriate solar cells on an inexpensive Si substrate. Epitaxial Ge on Si is used as a virtual substrate for III-V semiconductor growth. At long and very short wavelengths where PV efficiency is low, solar radiation is directed to a high temperature thermal storage tank for electricity generation using heat engines. The potential of using PV waste heat due to thermalization of high energy photoelectrons for electricity generation is also investigated. Detailed optical and thermal analysis show that with optimized design and neglecting optical component loss, system power conversion efficiency can reach 56%, including more than 16% absolute contribution from thermal storage.