333 research outputs found
Arthropod Consumption by Northern Bobwhite Chicks in Managed Tall Fescue Monocultures
An extensive amount of Conservation Reserve Program (CRP) habitat for northern bobwhite (Colinus virginianus) has been lost to planting of tall fescue (Schedonorus phoenix). We conducted foraging trials using human-imprinted bobwhite chicks (n 1â4 288) and collected terrestrial arthropods using a customized yard vacuum to assess the effects of 3 USDA mid-contract management (MCM) cost-share practices on chick foraging rates and arthropod prey selection in 36 tall fescue-dominated CRP fields in Illinois during 2008. We applied fall strip disking, fall glyphosate spraying, and fall glyphosate spraying followed by spring legume interseeding in alternating strips to 33% of each treatment field on a 3-year rotation. Glyphosate and glyphosate-interseeding treatments provided greater brood habitat benefits for bobwhite chicks than disking and control fields. Chicks consumed a greater abundance (P , 0.0001) and biomass (P 1â4 0.0017) of arthropods in managed fields than in unmanaged fields. Abundance and biomass of arthropods consumed by chicks were higher in glyphosate and glyphosate-interseeded strips with 1-, 2-, and 3-growing seasons post-treatment, but disking only provided this benefit for 1 growing season. Vacuum sampling provided a poor index of the availability of arthropods to bobwhite chicks, as measured by foraging of imprinted chicks. Vacuum sampling indicated arthropod abundance was greater in unmanaged than in managed fields (P 1â4 0.170). Custom vacuums are not an appropriate tool for measuring the abundance of arthropods important to bobwhite chicks in tall fescue CRP. Fall strip disking is an inferior MCM practice to glyphosate-based treatments in tall fescue- dominated CRP
Effects of Water-Level Management on Nesting Success of Common Loons
Water-level management is widespread and illustrates how contemporary climate can interact directly and indirectly with numerous biological and abiotic factors to influence reproductive success of wildlife species. We studied common loons, an iconic waterbird sensitive to timing and magnitude of waterlevel changes during the breeding season, using a before-after-control-impact design on large lakes in Voyageurs National Park (Minnesota, USA), to assess the effect of anthropogenic changes in hydroregime on their nesting success and productivity. We examined multiple competing a priori hypotheses in an information-theoretic framework, and predicted that magnitude of changes in loon productivity would be greater in the Namakan Reservoir, where water-level management was altered to mimic a more natural hydroregime, than in Rainy Lake, where management remained relatively unchanged. We determined outcomes from 278 nests during 2004â2006 by performing boat-based visits every 3â5 days, and measuring hydrologic, vegetative, and microtopographic covariates. Relative to comparably collected data for 260 total loon pairs during 1983â1986, productivity (chicks hatched/territorial pair) increased 95% in the Namakan Reservoir between the 2 time periods. Nest success declined in both lakes over the 2 study periods but less so in the Namakan Reservoir than in Rainy Lake. Flooding was a primary cause of nest failures (though second nests were less likely to flood). Nest predation appears to have increased considerably between the 2 study periods. Top-ranked models suggested that timing of nest initiation, probability of nest flooding, probability of nest stranding, and probability of nest success were each related to 2â4 factors, including date of initiation, timing of initiation relative to peak water levels, changes in the elevation of the nest edge, maximum waterlevel change between initiation and peak water levels, and maximum water-level change between initiation and nest outcome. The top model for all variables except stranding each garnered \u3e82% of total model weight. Results demonstrate that water-level management can be altered to benefit productivity of common loons. However, nuanced interactions between land-use change, invasive species, human development, recreation, climate change, and recovery of top predators may often complicate both management decisions and interpretation of water-level impacts on wildlife
Persistent enteric murine norovirus infection is associated with functionally suboptimal virus-specific CD8 T cell responses
Norovirus (NV) gastroenteritis is a major contributor to global morbidity and mortality, yet little is known about immune mechanisms leading to NV control. Previous studies using the murine norovirus (MNV) model have established a key role for T cells in MNV clearance. Despite these advances, important questions remain regarding the magnitude, location, and dynamics of the MNV-specific T cell response. To address these questions, we identified MNV-specific major histocompatibility complex (MHC) class I immunodominant epitopes using an overlapping peptide screen. One of these epitopes (amino acids 519 to 527 of open reading frame 2 [ORF2(519-527)]) was highly conserved among all NV genogroups. Using MHC class I peptide tetramers, we tracked MNV-specific CD8 T cells in lymphoid and mucosal sites during infection with two MNV strains with distinct biological behaviors, the acutely cleared strain CW3 and the persistent strain CR6. Here, we show that enteric MNV infection elicited robust T cell responses primarily in the intestinal mucosa and that MNV-specific CD8 T cells dynamically regulated the expression of surface molecules associated with activation, differentiation, and homing. Furthermore, compared to MNV-CW3 infection, chronic infection with MNV-CR6 resulted in fewer and less-functional CD8 T cells, and this difference was evident as early as day 8 postinfection. Finally, MNV-specific CD8 T cells were capable of reducing the viral load in persistently infected Rag1(â/â) mice, suggesting that these cells are a crucial component of NV immunity. Collectively, these data provide fundamental new insights into the adaptive immune response to two closely related NV strains with distinct biological behaviors and bring us closer to understanding the correlates of protective antiviral immunity in the intestine
Abortion attitudes: An overview of demographic and ideological differences
Despite being a defining issue in the culture war, the relative importance of the psychological predictors of abortion attitudes are poorly understood. We address this oversight here by reviewing existing findings and providing new evidence for the demographic and ideological correlates of abortion support. Throughout our review, we integrate new analyses of several large-scale, cross-sectional, and longitudinal datasets to provide the most complete empirical examination of abortion attitudes to date. Our review and new analyses indicate that abortion support is increasing (modestly) over time in both the US and New Zealand. We also show that a plurality of respondents (43.8%) in the US indicate that they are âpro-choiceâ across various elective and traumatic scenarios, whereas only 14.8% report being consistently âpro-lifeâ regardless of why an abortion is sought. Our review and new integrative analyses then demonstrate that age, religiosity, and conservatism correlate negatively, whereas Openness to Experience correlates positively, with abortion support. New analyses of heterosexual couples also reveal that womenâs and menâs religiosity uniquely decreases their romantic partnerâs abortion support. Finally, noting inconsistent gender differences in abortion support, we review evidence for the impact of traditional gender role attitudes and sexism on abortion support. Our review and theoretical analyses illustrate that, rather than misogyny, benevolent sexismâthe belief that women should be cherished and protectedâbest explains abortion opposition. We conclude that demographic and ideological variables, along with attitudes that revere women and motherhood, continue to undermine womenâs interpersonal, intergroup, and societal rights
Analytic frameworks for assessing dialogic argumentation in online learning environments
Over the last decade, researchers have developed sophisticated online learning environments to support students engaging in argumentation. This review first considers the range of functionalities incorporated within these online environments. The review then presents five categories of analytic frameworks focusing on (1) formal argumentation structure, (2) normative quality, (3) nature and function of contributions within the dialog, (4) epistemic nature of reasoning, and (5) patterns and trajectories of participant interaction. Example analytic frameworks from each category are presented in detail rich enough to illustrate their nature and structure. This rich detail is intended to facilitate researchersâ identification of possible frameworks to draw upon in developing or adopting analytic methods for their own work. Each framework is applied to a shared segment of student dialog to facilitate this illustration and comparison process. Synthetic discussions of each category consider the frameworks in light of the underlying theoretical perspectives on argumentation, pedagogical goals, and online environmental structures. Ultimately the review underscores the diversity of perspectives represented in this research, the importance of clearly specifying theoretical and environmental commitments throughout the process of developing or adopting an analytic framework, and the role of analytic frameworks in the future development of online learning environments for argumentation
Explore the concept of âlightâ and its interaction with matter: an inquiry-based science education project in primary school
The exploration process leading to the understanding of physical phenomena, such
as light and its interaction with matter, raises great interest and curiosity in children. However,
in most primary schools, children rarely have the opportunity to conduct science activities in
which they can engage in an enquiry process even if by the action of the teacher. In this
context, we have organised several in-service teacher training courses and carried out several
pedagogic interventions in Portuguese primary schools, with the aim of promoting inquirybased
science education. This article describes one of those projects, developed with a class of
the third grade, which explored the curricular topic âLight Experimentsâ. Various activities
were planned and implemented, during a total of ten hours spread over five lessons. The
specific objectives of this paper are: to illustrate and analyse the teaching and learning process
promoted in the classroom during the exploration of one of these lessons, and to assess
childrenâs learning three weeks after the lessons. The results suggest that children made
significant learning which persisted. We conclude discussing some processes that stimulated
childrenâ learning, including the importance of teacher questioning in scaffolding children's
learning and some didactic implications for teacher training.CIEC â Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), Portuga
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âIt feels like someone is hammering my feetâ: Understanding pain and its management from the perspective of people with Multiple Sclerosis
Background:
Pain affects around 63% of people with multiple sclerosis (pwMS). Biomedical treatments demonstrate limited efficacy. More research is needed to understand pain from the individualâs perspective in order to better inform a patient-centred approach that improves engagement, self-management and outcome.
Objective:
The objective of this paper is to explore pwMSâ experience and responses to pain, and their perspectives on pain management.
Methods:
Twenty-five in-depth, semi-structured telephone interviews were conducted. Interviews were audiotaped, transcribed and analysed using an inductive thematic analysis approach with elements of grounded theory.
Results:
Key themes included vivid descriptions of pain and beliefs that pain is unpredictable, a sign of damage and may worsen. Anger was a common emotional response. Two dominant pain management themes emerged: one related to pain reduction and another to acceptance. Those focusing on pain reduction appeared to engage in cycles in which they struggled with symptoms and experienced continued distress.
Conclusion:
Findings identify pain-related beliefs, emotional reactions and disparate pain-management attitudes. All may influence pwMSâ responses to pain and what they ask of their clinicians. Uncovering pwMSâ personal beliefs about pain, and introducing a broader biopsychosocial understanding of pain in the clinical context, may provide opportunities to rectify potentially unhelpful management choices and enhance pain acceptance
Grouping practices in the primary school: what influences change?
During the 1990s, there was considerable emphasis on promoting particular kinds of pupil grouping as a means of raising educational standards. This survey of 2000 primary schools explored the extent to which schools had changed their grouping practices in responses to this, the nature of the changes made and the reasons for those changes. Forty eight percent of responding schools reported that they had made no change. Twenty two percent reported changes because of the literacy hour, 2% because of the numeracy hour, 7% because of a combination of these and 21% for other reasons. Important influences on decisions about the types of grouping adopted were related to pupil learning and differentiation, teaching, the implementation of the national literacy strategy, practical issues and school self-evaluation
Low Complexity Regularization of Linear Inverse Problems
Inverse problems and regularization theory is a central theme in contemporary
signal processing, where the goal is to reconstruct an unknown signal from
partial indirect, and possibly noisy, measurements of it. A now standard method
for recovering the unknown signal is to solve a convex optimization problem
that enforces some prior knowledge about its structure. This has proved
efficient in many problems routinely encountered in imaging sciences,
statistics and machine learning. This chapter delivers a review of recent
advances in the field where the regularization prior promotes solutions
conforming to some notion of simplicity/low-complexity. These priors encompass
as popular examples sparsity and group sparsity (to capture the compressibility
of natural signals and images), total variation and analysis sparsity (to
promote piecewise regularity), and low-rank (as natural extension of sparsity
to matrix-valued data). Our aim is to provide a unified treatment of all these
regularizations under a single umbrella, namely the theory of partial
smoothness. This framework is very general and accommodates all low-complexity
regularizers just mentioned, as well as many others. Partial smoothness turns
out to be the canonical way to encode low-dimensional models that can be linear
spaces or more general smooth manifolds. This review is intended to serve as a
one stop shop toward the understanding of the theoretical properties of the
so-regularized solutions. It covers a large spectrum including: (i) recovery
guarantees and stability to noise, both in terms of -stability and
model (manifold) identification; (ii) sensitivity analysis to perturbations of
the parameters involved (in particular the observations), with applications to
unbiased risk estimation ; (iii) convergence properties of the forward-backward
proximal splitting scheme, that is particularly well suited to solve the
corresponding large-scale regularized optimization problem
Incidence, management, and outcomes of cardiovascular insufficiency in critically ill term and late preterm newborn infants
OBJECTIVE:
The objective of this study was to characterize the incidence, management, and short-term outcomes of cardiovascular insufficiency (CVI) in mechanically ventilated newborns, evaluating four separate prespecified definitions.
STUDY DESIGN:
Multicenter, prospective cohort study of infants â„34 weeks gestational age (GA) and on mechanical ventilation during the first 72 hours. CVI was prospectively defined as either (1) mean arterial pressure (MAP)â<âGA; (2) MAPâ<âGAâ+âsigns of inadequate perfusion; (3) any therapy for CVI; or (4) inotropic therapy. Short-term outcomes included death, days on ventilation, oxygen, and to full feedings and discharge.
RESULTS:
Of 647 who met inclusion criteria, 419 (65%) met â„1 definition of CVI. Of these, 98% received fluid boluses, 36% inotropes, and 17% corticosteroids. Of treated infants, 46% did not have CVI as defined by a MAPâ<âGAâ±âsigns of inadequate perfusion. Inotropic therapy was associated with increased mortality (11.1 vs. 1.3%; pâ<â0.05).
CONCLUSION:
More than half of the infants met at least one definition of CVI. However, almost half of the treated infants met none of the definitions. Inotropic therapy was associated with increased mortality. These findings can help guide the design of future studies of CVI in newborn
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