1,241 research outputs found

    Pockets of open cells and drizzle in marine stratocumulus

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    Microbial Species Coexistence Depends on the Host Environment

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    Organisms and their resident microbial communities form a complex and mostly stable ecosystem. It is known that the specific composition and abundance of certain bacterial species affect host health and fitness, but the processes that lead to these microbial patterns are unknown. We investigate this by deconstructing the simple microbiome of the freshwater polyp Hydra. We contrast the performance of its two main bacterial associates, Curvibacter and Duganella, on germfree hosts with two in vitro environments over time. We show that interactions within the microbiome but also the host environment lead to the observed species frequencies and abundances. More specifically, we find that both microbial species can only stably coexist in the host environment, whereas Duganella outcompetes Curvibacter in both in vitro environments irrespective of initial starting frequencies. While Duganella seems to benefit through secretions of Curvibacter, its competitive effect on Curvibacter depends upon direct contact. The competition might potentially be mitigated through the spatial distribution of the two microbial species on the host, which would explain why both species stably coexist on the host. Interestingly, the relative abundances of both species on the host do not match the relative abundances reported previously nor the overall microbiome carrying capacity as reported in this study. Both observations indicate that rare microbial community members might be relevant for achieving the native community composition and carrying capacity. Our study highlights that for dissecting microbial interactions the specific environmental conditions need to be replicated, a goal difficult to achieve with in vitro systems

    Comparison of loop-mediated isothermal amplification, polymerase chain reaction, and selective isolation assays for detection of Xanthomonas albilineans from sugarcane

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    A loop-mediated isothermal amplification (LAMP) assay was developed and compared to polymerase chain reaction (PCR), nested PCR, and selective isolation assays for detection of Xanthomonas albilineans, the causal agent of sugarcane leaf scald. The pathogen was isolated on selective medium from 44 out of 45 (98%) samples taken from symptomatic stalks, and from 44 out of 70 (63%) samples from asymptomatic stalks that were collected from plots with symptomatic stalks. Forty-two (93%), 41 (91%), and 42 (93%) symptomatic samples tested positive by LAMP, PCR and nested PCR, respectively. The pathogen was detected in 19 (27%), 8 (11%), and 25 (36%) of the 70 asymptomatic samples by LAMP, PCR and nested PCR, respectively. Symptomatic stalks were mainly, but not always, associated with high populations of the pathogen (107–109 CFU/ml), and asymptomatic stalks with low populations (<103 CFU/ml) or no bacteria. Although our LAMP and nested PCR methods detected 10 CFU/ml of X. albilineans in suspensions prepared with pure culture, they sometimes failed to detect the pathogen in samples with low pathogen populations. Isolation on selective medium along with another method should therefore be used for detection of the pathogen in asymptomatic stalks, especially in quarantine programs

    ARM Research in the Equatorial Western Pacific: A Decade and Counting

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    The tropical western Pacific (TWP) is an important climatic region. Strong solar heating, warm sea surface temperatures, and the annual progression of the intertropical convergence zone (ITCZ) across this region generate abundant convective systems, which through their effects on the heat and water budgets have a profound impact on global climate and precipitation. In order to accurately evaluate tropical cloud systems in models, measurements of tropical clouds, the environment in which they reside, and their impact on the radiation and water budgets are needed. Because of the remote location, ground-based datasets of cloud, atmosphere, and radiation properties from the TWP region have come primarily from short-term field experiments. While providing extremely useful information on physical processes, these short-term datasets are limited in statistical and climatological information. To provide longterm measurements of the surface radiation budget in the tropics and the atmospheric properties that affect it, the Atmospheric Radiation Measurement program established a measurement site on Manus Island, Papua New Guinea, in 1996 and on the island republic of Nauru in late 1998. These sites provide unique datasets now available for more than 10 years on Manus and Nauru. This article presents examples of the scientific use of these datasets including characterization of cloud properties, analysis of cloud radiative forcing, model studies of tropical clouds and processes, and validation of satellite algorithms. New instrumentation recently installed at the Manus site will provide expanded opportunities for tropical atmospheric science

    First International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions).

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    The purpose of this study is to obtain a consensus for the therapy of B3 lesions. The first International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions) including atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), classical lobular neoplasia (LN), papillary lesions (PL), benign phyllodes tumors (PT), and radial scars (RS) took place in January 2016 in Zurich, Switzerland organized by the International Breast Ultrasound School and the Swiss Minimally Invasive Breast Biopsy group-a subgroup of the Swiss Society of Senology. Consensus recommendations for the management and follow-up surveillance of these B3 lesions were developed and areas of research priorities were identified. The consensus recommendation for FEA, LN, PL, and RS diagnosed on core needle biopsy or vacuum-assisted biopsy (VAB) is to therapeutically excise the lesion seen on imaging by VAB and no longer by open surgery, with follow-up surveillance imaging for 5 years. The consensus recommendation for ADH and PT is, with some exceptions, therapeutic first-line open surgical excision. Minimally invasive management of selected B3 lesions with therapeutic VAB is acceptable as an alternative to first-line surgical excision

    Essentially English : Sherlock Holmes at the BBC

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    Sir Arthur Conan Doyle’s Sherlock Holmes stories, currently enjoying renewed popularity on television via the BBC’s Sherlock (2010- ), have been adapted for the screen countless times around the world. Arguably best remembered are Granada’s long-running strand with Jeremy Brett (1984-94), and the Universal film series of the 1940s, featuring Basil Rathbone and Nigel Bruce. Less frequently cited, however, are the two series produced by the BBC between 1965 and 1968, in which first Douglas Wilmer and later Peter Cushing took on the mantle of the Baker Street detective. Typically for the time – but against the wishes of the Conan Doyle estate - these programmes adopted a multi-camera studio model; a mode of production which made them less attractive to US networks than the single camera 35mm film output of commercial rivals such as ITC. Drawing upon material from the BBC’s Written Archives Centre, this article investigates the motivations underpinning the Corporation’s refusal to accommodate the estate’s exhortations to seek American co-production and utilise single camera filming, not least of which was the BBC’s stated desire to maintain the ‘essentially English’ quality of Sherlock Holmes. This decision would have significant repercussions for the series’ overseas saleability, and – despite impressive viewing figures and positive audience reaction at home in the UK – helped contribute to its ‘forgotten’ status with regard to the television canon

    Sister species diverge in modality-specific courtship signal form and function

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    Understanding the relative importance of different sources of selection (e.g., the environment, social/sexual selection) on the divergence or convergence of reproductive communication can shed light on the origin, maintenance, or even disappearance of species boundaries. Using a multistep approach, we tested the hypothesis that two presumed sister species of wolf spider with overlapping ranges and microhabitat use, yet differing degrees of sexual dimorphism, have diverged in their reliance on modality- specific courtship signaling. We predicted that male Schizocosa crassipalpata (no ornamentation) rely predominantly on diet-dependent vibratory signaling for mating success. In contrast, we predicted that male S. bilineata (black foreleg brushes) rely on diet-dependent visual signaling. We first tested and corroborated the sister-species relationship between S. crassipalpata and S. bilineata using phylogenomic scale data. Next, we tested for species-specific, diet-dependent vibratory and visual signaling by manipulating subadult diet and subsequently quantifying adult morphology and mature male courtship signals. As predicted, vibratory signal form was diet-dependent in S. crassipalpata, while visual ornamentation (brush area) was diet-dependent in S. bilineata. We then compared the species-specific reliance on vibratory and visual signaling by recording mating across artificially manipulated signaling environments (presence/absence of each modality in a 2 × 2 full factorial design). In accordance with our diet dependence results for S. crassipalpata, the presence of vibratory signaling was important for mating success. In contrast, the light and vibratory environment interacted to influence mating success in S. bilineata, with vibratory signaling being important only in the absence of light. We found no differences in overall activity patterns. Given that these species overlap in much of their range and microhabitat use, we suggest that competition for signaling space may have led to the divergence and differential use of sensory modalities between these sister species

    Fabrication and characterization of dual function nanoscale pH-scanning ion conductance microscopy (SICM) probes for high resolution pH mapping

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    The easy fabrication and use of nanoscale dual function pH-scanning ion conductance microscopy (SICM) probes is reported. These probes incorporate an iridium oxide coated carbon electrode for pH measurement and an SICM barrel for distance control, enabling simultaneous pH and topography mapping. These pH-SICM probes were fabricated rapidly from laser pulled theta quartz pipets, with the pH electrode prepared by in situ carbon filling of one of the barrels by the pyrolytic decomposition of butane, followed by electrodeposition of a thin layer of hydrous iridium oxide. The other barrel was filled with an electrolyte solution and Ag/AgCl electrode as part of a conductance cell for SICM. The fabricated probes, with pH and SICM sensing elements typically on the 100 nm scale, were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and various electrochemical measurements. They showed a linear super-Nernstian pH response over a range of pH (pH 2–10). The capability of the pH-SICM probe was demonstrated by detecting both pH and topographical changes during the dissolution of a calcite microcrystal in aqueous solution. This system illustrates the quantitative nature of pH-SICM imaging, because the dissolution process changes the crystal height and interfacial pH (compared to bulk), and each is sensitive to the rate. Both measurements reveal similar dissolution rates, which are in agreement with previously reported literature values measured by classical bulk methods

    Comparative Tuberculosis (TB) Prevention Effectiveness in Children of Bacillus Calmette-Guérin (BCG) Vaccines from Different Sources, Kazakhstan

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    Except during a 1-year period when BCG vaccine was not routinely administered, annual coverage of infants with Bacillus Calmette-Guérin (BCG) in Kazakhstan since 2002 has exceeded 95%. BCG preparations from different sources (Japan, Serbia, and Russia) or none were used exclusively in comparable 7-month time-frames, September through March, in 4 successive years beginning in 2002. Our objective was to assess relative effectiveness of BCG immunization.Although there were differences in prevention effectiveness observed among the three BCG vaccines, all were protective. The Japanese vaccine (currently used in Kazakhstan), the Serbian vaccine, and the Russian vaccine respectively were 69%, 43%, and 22% effective with respect to clinical TB notifications, and 92%, 82%, and 51% effective with respect to culture confirmed TB. All three vaccines were >70% effective with respect to TB meningitis.Potential limitations included considerations that 1) the methodology used was retrospective, 2) multiple risk factors could have varied between cohorts and affected prevention effectiveness measures, 3) most cases were clinically diagnosed, and TB culture-positive case numbers and TB meningitis case numbers were sparse, and 4) small variations in reported population TB burden could have affected relative risk of exposure for cohorts.All three BCG vaccines evaluated were protective against TB, and prevention effectiveness varied by manufacturer. When setting national immunization policy, consideration should be given to prevention effectiveness of BCG preparations

    Adolescent Religiosity and Selective Exposure to Television

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    Relying on the Adolescent Media Practice Model and selective exposure theory, this study investigated whether religious adolescents watch less mature television entertainment programs than their less religious peers. Program maturity was measured using V-chip ratings, with higher maturity scores indicating content that included more sexuality, violence, and/or adult and sexual language. The responses from 1,335 16- to 18-year-olds who completed Wave 2 of the National Study of Youth and Religion (NSYR) survey were analyzed. Findings indicate that religiosity contributes to explaining the variance in television maturity means, with more religious adolescents indicating a preference for less mature television entertainment. Gender, race, income, and parents’ monitoring of teens’ media were also found to influence television maturity. Teens’ attitudes toward premarital sex appeared to mediate the effect of religiosity on their television entertainment choices
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