5,767 research outputs found
Heritable Melanism and Parasitic Infection Both Result in Black-Spotted Mosquitofish
Male Gambusia holbrooki (Eastern Mosquitofish) express a heritable pigmentation polymorphism: ≈99% of males are silver, and only ≈1% have a melanic, black-spotted pattern. Sex-linkage, an autosomal modifier, and temperature control the expression of this heritable melanism. In many teleosts, melanin also accumulates around the site of parasitic invasion. We have identified black-spot disease in wild mosquitofish from their native habitat. Here, we demonstrate convergence upon the black-pigmented phenotype through two means: 1) heritable melanism, and 2) melanic spotting on the silver genotype that results from infection with immature encysted trematodes. Females are silver and express greater avoidance ofmelanic males during mating attempts. The resemblance of the black-spotted pattern of the melanic genotype to that of silver genotype infected with trematodes may affect the fitness ofmelanic males if females perceive them as diseased. Alternatively, females may shun parasitized silverfish because they resemble the melanic genotype, which is larger and has a larger mating orga
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Distinct mechanisms of Drosophila CRYPTOCHROME-mediated light-evoked membrane depolarization and in vivo clock resetting.
Drosophila CRYPTOCHROME (dCRY) mediates electrophysiological depolarization and circadian clock resetting in response to blue or ultraviolet (UV) light. These light-evoked biological responses operate at different timescales and possibly through different mechanisms. Whether electron transfer down a conserved chain of tryptophan residues underlies biological responses following dCRY light activation has been controversial. To examine these issues in in vivo and in ex vivo whole-brain preparations, we generated transgenic flies expressing tryptophan mutant dCRYs in the conserved electron transfer chain and then measured neuronal electrophysiological phototransduction and behavioral responses to light. Electrophysiological-evoked potential analysis shows that dCRY mediates UV and blue-light-evoked depolarizations that are long lasting, persisting for nearly a minute. Surprisingly, dCRY appears to mediate red-light-evoked depolarization in wild-type flies, absent in both cry-null flies, and following acute treatment with the flavin-specific inhibitor diphenyleneiodonium in wild-type flies. This suggests a previously unsuspected functional signaling role for a neutral semiquinone flavin state (FADH•) for dCRY. The W420 tryptophan residue located closest to the FAD-dCRY interaction site is critical for blue- and UV-light-evoked electrophysiological responses, while other tryptophan residues within electron transfer distance to W420 do not appear to be required for light-evoked electrophysiological responses. Mutation of the dCRY tryptophan residue W342, more distant from the FAD interaction site, mimics the cry-null behavioral light response to constant light exposure. These data indicate that light-evoked dCRY electrical depolarization and clock resetting are mediated by distinct mechanisms
Reaching urban female adolescents at key points of sexual and reproductive health transitions: evidence from a longitudinal study from Kenya
Urban areas include large numbers of adolescents (ages 15-19) and young adults (ages 20-24) who may have unmet sexual and reproductive health (SRH) needs. Worldwide, adolescents contribute 11% of births, many of which are in low and middle-income countries. This study uses recently collected longitudinal data from urban Kenyan women to examine the association between targeted intervention activities and adolescents‘ SRH transitions. The focus was on a female adolescent (15-19) sample and their transition to first sex and first pregnancy/birth. Multinomial logistic regression methods were used to examine whether exposure to program activities was associated with delays in transitions. Overall, a high percentage of adolescents were exposed to television activities with family planning messages. About a third were exposed to community events, program posters, or the Shujaaz comic book that included themes related to relationships and positive health outcomes using recognizable characters. Multivariate analyses found that exposure to the Shujaaz comic book was associated with remaining sexually inexperienced and never pregnant at end line. Future programs for urban adolescents should implement interventions that test novel media strategies, like the Shujaaz comic book, that may be more interesting for young people. Innovative strategies are needed to reach female adolescents in urban settings.Keywords: Urban; Kenya; Sexual Initiation; Pregnancy; Adolescent
The Fueling Diagram: Linking Galaxy Molecular-to-Atomic Gas Ratios to Interactions and Accretion
To assess how external factors such as local interactions and fresh gas
accretion influence the global ISM of galaxies, we analyze the relationship
between recent enhancements of central star formation and total
molecular-to-atomic (H2/HI) gas ratios, using a broad sample of field galaxies
spanning early-to-late type morphologies, stellar masses of 10^(7.2-11.2) Msun,
and diverse stages of evolution. We find that galaxies occupy several loci in a
"fueling diagram" that plots H2/HI vs. mass-corrected blue-centeredness, a
metric tracing the degree to which galaxies have bluer centers than the average
galaxy at their stellar mass. Spiral galaxies show a positive correlation
between H2/HI and mass-corrected blue-centeredness. When combined with previous
results linking mass-corrected blue-centeredness to external perturbations,
this correlation suggests a link between local galaxy interactions and
molecular gas inflow/replenishment. Intriguingly, E/S0 galaxies show a more
complex picture: some follow the same correlation, some are quenched, and a
distinct population of blue-sequence E/S0 galaxies (with masses below key
transitions in gas richness) defines a separate loop in the fueling diagram.
This population appears to be composed of low-mass merger remnants currently in
late- or post-starburst states, in which the burst first consumes the H2 while
the galaxy center keeps getting bluer, then exhausts the H2, at which point the
burst population reddens as it ages. Multiple lines of evidence suggest
connected evolutionary sequences in the fueling diagram. In particular,
tracking total gas-to-stellar mass ratios within the diagram provides evidence
of fresh gas accretion onto low-mass E/S0s emerging from central starbursts.
Drawing on a comprehensive literature search, we suggest that virtually all
galaxies follow the same evolutionary patterns found in our broad sample.Comment: 24 pages, 11 figures (table 4 available at
http://user.physics.unc.edu/~dstark/table4_csv.txt), accepted for publication
in Ap
Introducing Interprofessional Education and Care Concepts in a Geriatric Multilevel Centre: Development and Introduction of a Toolkit for Staff and Students
Background: Although interprofessional education (IPE) is not new, there has been limited research in IPE focused on the care of older adults. The objective of this study was to develop and implement an interprofessional education and care (IPE/C) toolkit, to help staff and students understand and apply the concepts of IPE/C.Methods and Findings: Focus groups identified staff and students’ understanding of IPE/C and informed development of an IPE/C toolkit comprised of IPE/C tools and resources. Five clinical teams (N = 51) attended workshops that introduced the toolkit and educated teams about IPE/C. Focus group participants had heard of but had limited exposure to IPE/C. Responses to the Attitudes Toward Health Care Teams (ATHT) questionnaire indicated a positive trend on all questions; 2 questions in subscale 1 were statistically significant (p = .01 & p = .005), indicating a positive attitude toward teams and teamwork. Several limitations were identified, including inconsistent attendance at workshops, scheduling challenges, and limited physician participation.Conclusions: This pilot project provided baseline data on staff and students’ understanding of and attitudes toward IPE/C in a multilevel geriatric centre and demonstrated that an IPE/C toolkit delivered via team workshops can enhance healthcare team attitudes. Next steps include expanding the rollout to other teams and introducing the toolkit to all staff and students
Individual, Neighborhood, and Situational Factors Associated with Violent Victimization and Offending
The criminological literature presents substantial evidence that victims and offenders in violent crimes share demographic characteristics, engage in similar lifestyles and activities, and reside in socially disorganized neighborhoods. However, research has examined these relationships separately using either victimization or offending data, and prior studies have not examined these relationships by comparing victims and offenders within the same incidents. This limits the effect of examining whether these factors are associated with victimization and offending in similar or distinct ways. Using a law enforcement database of victims (n = 1,248) and offenders (n = 1,735) involved within the same aggravated battery incidents (n = 1,015) in Bernalillo County, New Mexico, this research explores whether victims and offenders involved in non-lethal violence share certain individual, neighborhood and situational characteristics. Results suggest that victims and offenders live in socially disorganized neighborhoods and engage in risky lifestyles and violent offending behaviors in similar proportions. These findings highlight the overlapping factors associated with victimization and offending in non-lethal violent personal crimes. The implications of these findings are discussed
A Prospective Longitudinal Assessment of Medical Records for Diagnostic Substitution among Subjects Diagnosed with a Pervasive Developmental Disorder in the United States
Background: Previously, investigators suggested that diagnostic substitution from other diagnoses, e.g., mental retardation (MR) and/or cerebral palsy (CP) to pervasive developmental disorder (PDD) is a driving factor behind increases in PDD. This study evaluated potential diagnostic substitution among subjects diagnosed with PDD vs MR or CP by examining birth characteristic overlap.Methods: SAS® and StatsDirect software examined medical records for subjects within the Vaccine Safety Datalink (VSD) database who were Health Maintenance Organization (HMO)-enrolled from birth until diagnosed with an International Classification of Disease, 9th revision (ICD-9) outcome of PDD (299.xx, n=84), CP (343.xx, n=300), or MR (317.xx, 318.xx, or 319.xx, n=51).Results: Subjects with PDD had significantly (p<0.01) increased: male/female ratio (PDD=5.5 vs CP=1.5 or MR=1.3), mean age of initial diagnosis in years (PDD=3.13 vs CP=1.09 or MR=1.62), mean gestational age in weeks at birth (PDD=38.73 vs CP=36.20 or MR=34.84), mean birth weight in grams (PDD=3,368 vs CP=2,767 or MR=2,406), and mean Appearance-Pulse-Grimace-Activity-Respiration (APGAR) scores at 1 minute (PDD=7.82 vs CP=6.37 or MR=6.76) and 5 minutes (PDD=8.77 vs CP=7.92 or MR=8.04), as compared to subjects diagnosed with CP or MR.Conclusion: This study suggests diagnostic substitution cannot fully explain increased PDD prevalence during the 1990s within the United States
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