Primer selection impacts specific population abundances but not community dynamics in a monthly time-series 16S rRNA gene amplicon analysis of coastal marine bacterioplankton.

Primers targeting the 16S small subunit ribosomal RNA marker gene, used to characterize bacterial and archaeal communities, have recently been re-evaluated for marine planktonic habitats. To investigate whether primer selection affects the ecological interpretation of bacterioplankton populations and community dynamics, amplicon sequencing with four primer sets targeting several hypervariable regions of the 16S rRNA gene was conducted on both mock communities constructed from cloned 16S rRNA genes and a time-series of DNA samples from the temperate coastal Santa Barbara Channel. Ecological interpretations of community structure (delineation of depth and seasonality, correlations with environmental factors) were similar across primer sets, while population dynamics varied. We observed substantial differences in relative abundances of taxa known to be poorly resolved by some primer sets, such as Thaumarchaeota and SAR11, and unexpected taxa including Roseobacter clades. Though the magnitude of relative abundances of common OTUs differed between primer sets, the relative abundances of the OTUs were nonetheless strongly correlated. We do not endorse one primer set but rather enumerate strengths and weaknesses to facilitate selection appropriate to a system or experimental goal. While 16S rRNA gene primer bias suggests caution in assessing quantitative population dynamics, community dynamics appear robust across studies using different primers

Apparatus and Method for Dispersing Nano-Elements to Assemble Device

An apparatus for dispersing a first plurality of conductive elongated nano-elements distributed within a carrier-fluid to assemble a conductive device made of a first charge-receptive area of a support surface to which at least one nano-element has attached, including: a nozzle through which the elongated nano-elements are directed such that the nano-elements pass through an electromagnetic field for imparting a preselected charge thereto, and toward at least the first charge-receptive area. The charge-receptive area is given a charge such that it attracts a first end-portion of one of the nano-elements. Also, a method of assembling a conductive device. Steps include: applying a first charge to the first charge-receptive area to attract a first end-portion of at least one nano-element; and dispersing from a nozzle, the plurality of elongated nano-elements distributed within a carrier-fluid initially contained in a reservoir, such that the nano-elements pass through an electromagnetic field for imparting a preselected charge thereto and toward the first charge-receptive area

The use of spirometry in a primary care setting

Elizabeth A Blain, Timothy J CraigPenn State Hershey Medical Center, Hershey, PA, USAObjective: To determine the use of spirometry in family practice, internal medicine, and pediatric outpatient settings.Methods: Data were collected from 45 outpatient offices in the central Pennsylvania area via phone survey that asked a set of four questions: 1) Do you have spirometry in your office? 2) Do you use spirometry for asthma patients? 3) In what situation do you use spirometry for? 4) Do you use spirometry more for chronic obstructive pulmonary disease (COPD) or asthma? Results: It was found that pediatricians used spirometry 66% of the time, family practitioners 47% of the time, and internal medicine practitioners 60% of the time. Of those who did not use spirometry, 94% stated that they refer to a hospital if they required spirometry and 6% referred to subspecialists if the patient required spirometry. 10% of pediatricians performed the test on each asthma visit, otherwise the others used it only for exacerbations or as a baseline. No internists used spirometry regularly for asthma patients, and 22% used it more for COPD. In family practice only 14% used spirometry routinely at each visit for asthma patients.Conclusions: Pediatricians used spirometry more often in the outpatient setting than other specialists, followed closely by internal medicine physicians. Family practice physicians were the least likely to use spirometry. Multiple barriers seemed to prevent routine use of spirometry, but no one barrier accounted for the majority.Keywords: spirometry, asthma, primary car

Hidden Error Variance Theory. Part I: Exposition and Analytic Model

Abstract A conundrum of predictability research is that while the prediction of flow-dependent error distributions is one of its main foci, chaos fundamentally hides flow-dependent forecast error distributions from empirical observation. Empirical estimation of such error distributions requires a large sample of error realizations given the same flow-dependent conditions. However, chaotic elements of the flow and the observing network make it impossible to collect a large enough conditioned error sample to empirically define such distributions and their variance. Such conditional variances are "hidden." Here, an exposition of the problem is developed from an ensemble Kalman filter data assimilation system applied to a 10-variable nonlinear chaotic model and 25 000 replicate models. The 25 000 replicates reveal the error variances that would otherwise be hidden. It is found that the inverse-gamma distribution accurately approximates the posterior distribution of conditional error variances given an imperfect ensemble variance and provides a reasonable approximation to the prior climatological distribution of conditional error variances. A new analytical model shows how the properties of a likelihood distribution of ensemble variances given a true conditional error variance determine the posterior distribution of error variances given an ensemble variance. The analytically generated distributions are shown to satisfactorily fit empirically determined distributions. The theoretical analysis yields a rigorous interpretation and justification of hybrid error variance models that linearly combine static and flow-dependent estimates of forecast error variance; in doing so, it also helps justify and inform hybrid error covariance models

The Impacts of Sprawl on Biodiversity: the Ant Fauna of the Lower Florida Keys

Sprawling development can affect species composition by increasing the rate of invasion by non-native species, and decreasing the persistence of native species. This paper briefly reviews the scientific literature on the impacts of sprawl on biological diversity, with specific emphasis on the influence of sprawl on non-native species richness. We then explore the relationship between sprawl and biodiversity using a data set of ant species collected from 46 habitat patches located in the increasingly suburbanized Florida Keys, USA. We quantified sprawl as the proximity of roads and amount of development surrounding a habitat patch. Using bait transects, we identified 24 native and 18 non-native species of ants. Neither the overall number of native species nor the number of rare native species were significantly affected by the amount of development or proximity to roads, however, the number of non-native species was significantly correlated with the amount of development. Surprisingly, the number of native species and rare native species was significantly positively correlated with the number of non-native species. Areas that supported many species of native ants also supported a diverse non-native ant fauna, and the species distribution was highly nested. Currently, the native ant fauna of the Florida Keys does not appear to be dramatically influenced by sprawl, however, if development increases, the number of non-native ants may increase, and many of these species have been documented as decreasing native ant diversity. If development plateaus, there is evidence that the native ant fauna could persist and could decrease non-native species richness through competition or predation

The Impacts of Sprawl on Biodiversity: the Ant Fauna of the Lower Florida Keys

Sprawling development can affect species composition by increasing the rate of invasion by non-native species, and decreasing the persistence of native species. This paper briefly reviews the scientific literature on the impacts of sprawl on biological diversity, with specific emphasis on the influence of sprawl on non-native species richness. We then explore the relationship between sprawl and biodiversity using a data set of ant species collected from 46 habitat patches located in the increasingly suburbanized Florida Keys, USA. We quantified sprawl as the proximity of roads and amount of development surrounding a habitat patch. Using bait transects, we identified 24 native and 18 non-native species of ants. Neither the overall number of native species nor the number of rare native species were significantly affected by the amount of development or proximity to roads, however, the number of non-native species was significantly correlated with the amount of development. Surprisingly, the number of native species and rare native species was significantly positively correlated with the number of non-native species. Areas that supported many species of native ants also supported a diverse non-native ant fauna, and the species distribution was highly nested. Currently, the native ant fauna of the Florida Keys does not appear to be dramatically influenced by sprawl, however, if development increases, the number of non-native ants may increase, and many of these species have been documented as decreasing native ant diversity. If development plateaus, there is evidence that the native ant fauna could persist and could decrease non-native species richness through competition or predation

"You Know You Are Sick, Why Do You Carry A Pregnancy Again?" Applying the Socio-Ecological Model to Understand Barriers to PMTCT Service Utilization in Western Kenya.

ObjectiveThroughout most of sub-Saharan Africa (SSA), prevention of mother-to-child transmission (PMTCT) services are readily available. However, PMTCT programs in SSA have had suboptimal performance compared to other regions of the world. The main objective of this study is to explore the socio-ecological and individual factors influencing the utilization of PMTCT services among HIV-positive pregnant women in western Kenya using a social ecological model as our analytical lens.MethodsData were collected using in-depth interviews with 33 HIV-infected women attending government health facilities in rural western Kenya. Women with HIV-infected infants aged between 6 weeks to 6 months with a definitive diagnosis of HIV in the infant, as well as those with an HIV-negative test result in the infant were interviewed between November 2012 and June 2013. Coding and analysis of the transcripts followed grounded theory tenets. Coding reports were discussed in a series of meetings held among the authors. We then employed constant comparative analysis to discover dominant individual, family, society and structural determinants of PMTCT use.ResultsBarriers to women's utilization of PMTCT services fell within the broad constructs of the socio-ecological model of individual, family, society and structural determinants. Several themes cut across the different steps of PMTCT cascade and relate to different constructs of the socio-ecological model. These themes include: self-motivation, confidence and resilience, family support, absence or reduced stigma, right provider attitude and quality of health services provided. We also found out that these factors ensured enhanced maternal health and HIV negative children.ConclusionThe findings of this study suggest that a woman's social environment is an important determinant of MTCT. PMTCT Interventions must comprehensively address multiple factors across the different ecological levels. More research is however required for the development of multi-component interventions that combine strategies at different ecological levels

Chandra Observation of the Radio Source / X-ray Gas Interaction in the Cooling Flow Cluster Abell 2052

We present a Chandra observation of Abell 2052, a cooling flow cluster with a central cD that hosts the complex radio source 3C 317. The data reveal ``holes'' in the X-ray emission that are coincident with the radio lobes. The holes are surrounded by bright ``shells'' of X-ray emission. The data are consistent with the radio source displacing and compressing, and at the same time being confined by, the X-ray gas. The compression of the X-ray shells appears to have been relatively gentle and, at most, slightly transonic. The pressure in the X-ray gas (the shells and surrounding cooler gas) is approximately an order of magnitude higher than the minimum pressure derived for the radio source, suggesting that an additional source of pressure is needed to support the radio plasma. The compression of the X-ray shells has speeded up the cooling of the shells, and optical emission line filaments are found coincident with the brightest regions of the shells.Comment: accepted for publication in ApJ Letters; for high-resolution color figures, see http://www.astro.virginia.edu/~elb6n/abell2052.htm