2,823 research outputs found
The benefits of child-centered play therapy and filial therapy for pre-school-aged children with reactive attachment disorder and their famiies
The purpose of this study was to investigate, from a theoretical perspective, the best treatment approach for preschool-aged children with Reactive Attachment Disorder. The challenges and needs of these children can be extensive, and the search for effective treatment is ongoing. Two specific questions of focus were: How are the theories behind Non-Directive Play Therapy/Child-Centered Play Therapy and Filial Therapy useful in conceptualizing the experience of therapy for a child with attachment disorder? And, how could these treatments be used to benefit children with attachment disorders and their families? The research for this paper involved a literature review of peer-reviewed articles on Reactive Attachment Disorder (RAD) and treatment, original sources describing Attachment Theory, Non-Directive Play Therapy and Filial Therapy, and the DSM-IV-TR and ICD-10. Both types of therapy were found to be helpful for children with RAD because they create a therapeutic relationship that encourages secure attachment, allow children to process trauma as needed, and provide conditions which help children build affect-regulation, improve self-concept and regain healthy development. Filial Therapy showed an additional benefit in training parents to provide ideal caregiving conditions. A comprehensive assessment and treatment program, utilizing aspects of both treatment types was suggested for children with Reactive Attachment Disorder and their families; it includes the potential for use in clinical settings, child welfare investigations and with foster and adoptive families
Bacterial community diversity and variation in spray water sources and the tomato fruit surface
<p>Abstract</p> <p>Background</p> <p>Tomato (<it>Solanum lycopersicum</it>) consumption has been one of the most common causes of produce-associated salmonellosis in the United States. Contamination may originate from animal waste, insects, soil or water. Current guidelines for fresh tomato production recommend the use of potable water for applications coming in direct contact with the fruit, but due to high demand, water from other sources is frequently used. We sought to describe the overall bacterial diversity on the surface of tomato fruit and the effect of two different water sources (ground and surface water) when used for direct crop applications by generating a 454-pyrosequencing 16S rRNA dataset of these different environments. This study represents the first in depth characterization of bacterial communities in the tomato fruit surface and the water sources commonly used in commercial vegetable production.</p> <p>Results</p> <p>The two water sources tested had a significantly different bacterial composition. Proteobacteria was predominant in groundwater samples, whereas in the significantly more diverse surface water, abundant phyla also included Firmicutes, Actinobacteria and Verrucomicrobia. The fruit surface bacterial communities on tomatoes sprayed with both water sources could not be differentiated using various statistical methods. Both fruit surface environments had a high representation of Gammaproteobacteria, and within this class the genera <it>Pantoea </it>and <it>Enterobacter </it>were the most abundant.</p> <p>Conclusions</p> <p>Despite the major differences observed in the bacterial composition of ground and surface water, the season long use of these very different water sources did not have a significant impact on the bacterial composition of the tomato fruit surface. This study has provided the first next-generation sequencing database describing the bacterial communities living in the fruit surface of a tomato crop under two different spray water regimes, and therefore represents an important step forward towards the development of science-based metrics for Good Agricultural Practices.</p
Predicting the cosmological constant with the scale-factor cutoff measure
It is well known that anthropic selection from a landscape with a flat prior
distribution of cosmological constant Lambda gives a reasonable fit to
observation. However, a realistic model of the multiverse has a physical volume
that diverges with time, and the predicted distribution of Lambda depends on
how the spacetime volume is regulated. We study a simple model of the
multiverse with probabilities regulated by a scale-factor cutoff, and calculate
the resulting distribution, considering both positive and negative values of
Lambda. The results are in good agreement with observation. In particular, the
scale-factor cutoff strongly suppresses the probability for values of Lambda
that are more than about ten times the observed value. We also discuss several
qualitative features of the scale-factor cutoff, including aspects of the
distributions of the curvature parameter Omega and the primordial density
contrast Q.Comment: 16 pages, 6 figures, 2 appendice
Cosmological Feedback from High-Redshift Dwarf Galaxies
We model how repeated supernova explosions in high-redshift dwarf starburst
galaxies drive superbubbles and winds out of the galaxies. We compute the
efficiencies of metal and mass ejection and energy transport from the galactic
potentials, including the effect of cosmological infall of external gas. The
starburst bubbles quickly blow out of small, high-redshift, galactic disks, but
must compete with the ram pressure of the infalling gas to escape into
intergalactic space. We show that the assumed efficiency of the star formation
rate dominates the bubble evolution and the metal, mass, and energy feedback
efficiencies. With star formation efficiency f*=0.01, the ram pressure of
infall can confine the bubbles around high-redshift dwarf galaxies with
circular velocities v_c>52 km/s. We can expect high metal and mass ejection
efficiencies, and moderate energy transport efficiencies in halos with
v_c~30-50 km/s and f*~0.01 as well as in halos with v_c~100 km/s and f*>>0.01.
Such haloes collapse successively from 1-2 sigma peaks in LambdaCDM Gaussian
density perturbations as time progresses. These dwarf galaxies can probably
enrich low and high-density regions of intergalactic space with metals to
10^-3-10^-2 Zsun as they collapse at z~8 and z<5 respectively. They also may be
able to provide adequate turbulent energy to prevent the collapse of other
nearby halos, as well as to significantly broaden Lyman-alpha absorption lines
to v_rms~20-40 km/s. We compute the timescales for the next starbursts if gas
freely falls back after a starburst, and find that, for star formation
efficiencies as low as f*<0.01, the next starburst should occur in less than
half the Hubble time at the collapse redshift. This suggests that episodic star
formation may be ubiquitous in dwarf galaxies.Comment: Accepted for ApJ v613, 60 pages, 15 figure
Constraints on the relationship between stellar mass and halo mass at low and high redshift
We use a statistical approach to determine the relationship between the
stellar masses of galaxies and the masses of the dark matter halos in which
they reside. We obtain a parameterized stellar-to-halo mass (SHM) relation by
populating halos and subhalos in an N-body simulation with galaxies and
requiring that the observed stellar mass function be reproduced. We find good
agreement with constraints from galaxy-galaxy lensing and predictions of
semi-analytic models. Using this mapping, and the positions of the halos and
subhalos obtained from the simulation, we find that our model predictions for
the galaxy two-point correlation function (CF) as a function of stellar mass
are in excellent agreement with the observed clustering properties in the SDSS
at z=0. We show that the clustering data do not provide additional strong
constraints on the SHM function and conclude that our model can therefore
predict clustering as a function of stellar mass. We compute the conditional
mass function, which yields the average number of galaxies with stellar masses
in the range [m, m+dm] that reside in a halo of mass M. We study the redshift
dependence of the SHM relation and show that, for low mass halos, the SHM ratio
is lower at higher redshift. The derived SHM relation is used to predict the
stellar mass dependent galaxy CF and bias at high redshift. Our model predicts
that not only are massive galaxies more biased than low mass ones at all
redshifts, but the bias increases more rapidly with increasing redshift for
massive galaxies than for low mass ones. We present convenient fitting
functions for the SHM relation as a function of redshift, the conditional mass
function, and the bias as a function of stellar mass and redshift.Comment: 21 pages, 17 figures, discussion enlarged, one more figure, updated
references, accepted for publication in Ap
Dynamical Dark Energy simulations: high accuracy Power Spectra at high redshift
Accurate predictions on non--linear power spectra, at various redshift z,
will be a basic tool to interpret cosmological data from next generation mass
probes, so obtaining key information on Dark Energy nature. This calls for high
precision simulations, covering the whole functional space of w(z) state
equations and taking also into account the admitted ranges of other
cosmological parameters; surely a difficult task. A procedure was however
suggested, able to match the spectra at z=0, up to k~3, hMpc^{-1}, in
cosmologies with an (almost) arbitrary w(z), by making recourse to the results
of N-body simulations with w = const. In this paper we extend such procedure to
high redshift and test our approach through a series of N-body gravitational
simulations of various models, including a model closely fitting WMAP5 and
complementary data. Our approach detects w= const. models, whose spectra meet
the requirement within 1% at z=0 and perform even better at higher redshift,
where they are close to a permil precision. Available Halofit expressions,
extended to (constant) w \neq -1 are unfortunately unsuitable to fit the
spectra of the physical models considered here. Their extension to cover the
desired range should be however feasible, and this will enable us to match
spectra from any DE state equation.Comment: method definitely improved in semplicity and efficacy,accepted for
publication on JCA
Characterization of microflora in Latin-style cheeses by next-generation sequencing technology
Background
Cheese contamination can occur at numerous stages in the manufacturing process including the use of improperly pasteurized or raw milk. Of concern is the potential contamination by Listeria monocytogenes and other pathogenic bacteria that find the high moisture levels and moderate pH of popular Latin-style cheeses like queso fresco a hospitable environment. In the investigation of a foodborne outbreak, samples typically undergo enrichment in broth for 24 hours followed by selective agar plating to isolate bacterial colonies for confirmatory testing. The broth enrichment step may also enable background microflora to proliferate, which can confound subsequent analysis if not inhibited by effective broth or agar additives. We used 16S rRNA gene sequencing to provide a preliminary survey of bacterial species associated with three brands of Latin-style cheeses after 24-hour broth enrichment. Results
Brand A showed a greater diversity than the other two cheese brands (Brands B and C) at nearly every taxonomic level except phylum. Brand B showed the least diversity and was dominated by a single bacterial taxon, Exiguobacterium, not previously reported in cheese. This genus was also found in Brand C, although Lactococcus was prominent, an expected finding since this bacteria belongs to the group of lactic acid bacteria (LAB) commonly found in fermented foods. Conclusions
The contrasting diversity observed in Latin-style cheese was surprising, demonstrating that despite similarity of cheese type, raw materials and cheese making conditions appear to play a critical role in the microflora composition of the final product. The high bacterial diversity associated with Brand A suggests it may have been prepared with raw materials of high bacterial diversity or influenced by the ecology of the processing environment. Additionally, the presence ofExiguobacterium in high proportions (96%) in Brand B and, to a lesser extent, Brand C (46%), may have been influenced by the enrichment process. This study is the first to define Latin-style cheese microflora using Next-Generation Sequencing. These valuable preliminary data will direct selective tailoring of agar formulations to improve culture-based detection of pathogens in Latin-style cheese
A Quantitative Content Analysis of Mercer University Theses
Quantitative content analysis of a body of research not only helps budding researchers understand the culture, language, and expectations of scholarship, it helps identify deficiencies and inform policy and practice. Because of these benefits, an analysis of a census of 980 Mercer University M.Ed., Ed.S., and doctoral theses was conducted. Each thesis was coded on 10 variables. The descriptive characteristics of the theses, the predictors of the length of the theses, and the predictors of the type of research method used were investigated. The main results were that: (a) the vast majority of thesis authors was female, (b) the number of qualitative theses was on the rise, (c) there were slight variations in research method and length based on location of publication, (d) the page length of M.Ed. theses had been slightly decreasing over time, (e) mathematics instruction was the most frequent subject descriptor of theses, and (f) the proportion of male authors increased over time
Geographic Population Structure of the Sugarcane Borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), in the Southern United States
The sugarcane borer moth, Diatraea saccharalis, is widespread throughout the Western Hemisphere, and is considered an introduced species in the southern United States. Although this moth has a wide distribution and is a pest of many crop plants including sugarcane, corn, sorghum and rice, it is considered one species. The objective was to investigate whether more than one introduction of D. saccharalis had occurred in the southern United States and whether any cryptic species were present. We field collected D. saccharalis in Texas, Louisiana and Florida in the southern United States. Two molecular markers, AFLPs and mitochondrial COI, were used to examine genetic variation among these regional populations and to compare the sequences with those available in GenBank and BOLD. We found geographic population structure in the southern United States which suggests two introductions and the presence of a previously unknown cryptic species. Management of D. saccharalis would likely benefit from further investigation of population genetics throughout the range of this species
Disentangling protostellar evolutionary stages in clustered environments using Spitzer-IRS spectra and comprehensive SED modeling
When studying the evolutionary stages of protostars that form in clusters,
the role of any intracluster medium cannot be neglected. High foreground
extinction can lead to situations where young stellar objects (YSOs) appear to
be in earlier evolutionary stages than they actually are, particularly when
using simple criteria like spectral indices. To address this issue, we have
assembled detailed SED characterizations of a sample of 56 Spitzer-identified
candidate YSOs in the clusters NGC 2264 and IC 348. For these, we use spectra
obtained with the Infrared Spectrograph onboard the Spitzer Space Telescope and
ancillary multi-wavelength photometry. The primary aim is twofold: 1) to
discuss the role of spectral features, particularly those due to ices and
silicates, in determining a YSO's evolutionary stage, and 2) to perform
comprehensive modeling of spectral energy distributions (SEDs) enhanced by the
IRS data. The SEDs consist of ancillary optical-to-submillimeter
multi-wavelength data as well as an accurate description of the 9.7 micron
silicate feature and of the mid-infrared continuum derived from line-free parts
of the IRS spectra. We find that using this approach, we can distinguish
genuine protostars in the cluster from T Tauri stars masquerading as protostars
due to external foreground extinction. Our results underline the importance of
photometric data in the far-infrared/submillimeter wavelength range, at
sufficiently high angular resolution to more accurately classify cluster
members. Such observations are becoming possible now with the advent of the
Herschel Space Observatory.Comment: Accepted for publication in Ap
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