450 research outputs found
Merchant mothers and fishermen fathers : parental investment and subsistence work among the boat-dwelling Shodagor of rural Bangladesh
This dissertation addresses three general research questions. First, what are the socioecological conditions that lead Shodagor families to employ particular strategies in order to balance subsistence work and childcare? Second, why do Shodagor men and women pursue particular occupational strategies that are cross-culturally unusual while others divide labor in ways that are more in line with other societies? And third, how do Shodagor subsistence and childcare strategies, all of which are concentrated within the nuclear family and influenced by the constraints of the Shodagor socioecology, influence nutritional outcomes for children and parents? I find that the concentration of resource sharing and childcare duties within the nuclear family is associated with husbands and wives cooperating in order to fulfill a family's subsistence and childcare needs. I also find that specific aspects of the ecology -- how far an individual lives from a major market, and how far he or she lives from the Meghna River -- as well as a family's childcare needs play key roles in determining the specific strategies families will employ in order to meet those needs. Finally, I show that while some factors concentrated within the nuclear family influence Shodagor health outcomes within the family in accordance with theoretical and cross-cultural predictions, others do not. These findings have implications for human behavioral ecological theory, which are discussed
Studying Parallel Evolutionary Algorithms: The cellular Programming Case
Parallel evolutionary algorithms, studied to some extent over the past few years, have proven empirically worthwhileâthough there seems to be lacking a better understanding of their workings. In this paper we concentrate on cellular (fine-grained) models, presenting a number of statistical measures, both at the genotypic and phenotypic levels. We demonstrate the application and utility of these measures on a specific example, that of the cellular programming evolutionary algorithm, when used to evolve solutions to a hard problem in the cellular-automata domain, known as synchronization
Arctic air pollution: Challenges and opportunities for the next decade
The Arctic is a sentinel of global change. This region is influenced by multiple physical and socio-economic drivers and feedbacks, impacting both the natural and human environment. Air pollution is one such driver that impacts Arctic climate change, ecosystems and health but significant uncertainties still surround quantification of these effects. Arctic air pollution includes harmful trace gases (e.g. tropospheric ozone) and particles (e.g. black carbon, sulphate) and toxic substances (e.g. polycyclic aromatic hydrocarbons) that can be transported to the Arctic from emission sources located far outside the region, or emitted within the Arctic from activities including shipping, power production, and other industrial activities. This paper qualitatively summarizes the complex science issues motivating the creation of a new international initiative, PACES (air Pollution in the Arctic: Climate, Environment and Societies). Approaches for coordinated, international and interdisciplinary research on this topic are described with the goal to improve predictive capability via new understanding about sources, processes, feedbacks and impacts of Arctic air pollution. Overarching research actions are outlined, in which we describe our recommendations for 1) the development of trans-disciplinary approaches combining social and economic research with investigation of the chemical and physical aspects of Arctic air pollution; 2) increasing the quality and quantity of observations in the Arctic using long-term monitoring and intensive field studies, both at the surface and throughout the troposphere; and 3) developing improved predictive capability across a range of spatial and temporal scales
Seasonality of aerosol optical properties in the Arctic
Given the sensitivity of the Arctic climate to short-lived climate forcers,
long-term in situ surface measurements of aerosol parameters are useful in
gaining insight into the magnitude and variability of these climate forcings.
Seasonality of aerosol optical properties â including the aerosol
light-scattering coefficient, absorption coefficient, single-scattering
albedo, scattering Ă
ngstrĂśm exponent, and asymmetry parameter â are
presented for six monitoring sites throughout the Arctic: Alert, Canada;
Barrow, USA; Pallas, Finland; Summit, Greenland; Tiksi, Russia; and Zeppelin
Mountain, Ny-Ă
lesund, Svalbard, Norway. Results show annual variability
in all parameters, though the seasonality of each aerosol optical property
varies from site to site. There is a large diversity in magnitude and
variability of scattering coefficient at all sites, reflecting differences in
aerosol source, transport, and removal at different locations throughout the
Arctic. Of the Arctic sites, the highest annual mean scattering coefficient
is measured at Tiksi (12.47 Mmâ1), and the lowest annual mean
scattering coefficient is measured at Summit (1.74 Mmâ1). At most
sites, aerosol absorption peaks in the winter and spring, and has a minimum
throughout the Arctic in the summer, indicative of the Arctic haze
phenomenon; however, nuanced variations in seasonalities suggest that this
phenomenon is not identically observed in all regions of the Arctic. The
highest annual mean absorption coefficient is measured at Pallas
(0.48 Mmâ1), and Summit has the lowest annual mean absorption
coefficient (0.12 Mmâ1). At the Arctic monitoring stations analyzed
here, mean annual single-scattering albedo ranges from 0.909 (at Pallas) to
0.960 (at Barrow), the mean annual scattering Ă
ngstrĂśm exponent
ranges from 1.04 (at Barrow) to 1.80 (at Summit), and the mean asymmetry
parameter ranges from 0.57 (at Alert) to 0.75 (at Summit). Systematic
variability of aerosol optical properties in the Arctic supports the notion
that the sites presented here measure a variety of aerosol populations, which
also experience different removal mechanisms. A robust conclusion from the
seasonal cycles presented is that the Arctic cannot be treated as one common
and uniform environment but rather is a region with ample spatiotemporal
variability in aerosols. This notion is important in considering the design
or aerosol monitoring networks in the region and is important for informing
climate models to better represent short-lived aerosol climate forcers in
order to yield more accurate climate predictions for the Arctic.</p
Effects Of Length, Complexity, And Grammatical Correctness On Stuttering In Spanish-Speaking Preschool Children
Purpose: To explore the effects of utterance length, syntactic complexity, and grammatical correctness on stuttering in the spontaneous speech of young, monolingual Spanish-speaking children. Method: Spontaneous speech samples of 11 monolingual Spanish-speaking children who stuttered, ages 35 to 70 months, were examined. Mean number of syllables, total number of clauses, utterance complexity (i.e., containing no clauses, simple clauses, or subordinate and/or conjoined clauses), and grammatical correctness (i.e., the presence or absence of morphological and syntactical errors) in stuttered and fluent utterances were compared. Results: Findings revealed that stuttered utterances in Spanish tended to be longer and more often grammatically incorrect, and contain more clauses, including more subordinate and/or conjoined clauses. However, when controlling for the interrelatedness of syllable number and clause number and complexity, only utterance length and grammatical incorrectness were significant predictors of stuttering in the spontaneous speech of these Spanish-speaking children. Use of complex utterances did not appear to contribute to the prediction of stuttering when controlling for utterance length. Conclusions: Results from the present study were consistent with many earlier reports of English-speaking children. Both length and grammatical factors appear to affect stuttering in Spanish-speaking children. Grammatical errors, however, served as the greatest predictor of stuttering.Communication Sciences and Disorder
Precision health: A nursing perspective
Precision health refers to personalized healthcare based on a person's unique genetic, genomic, or omic composition within the context of lifestyle, social, economic, cultural and environmental influences to help individuals achieve well-being and optimal health. Precision health utilizes big data sets that combine omics (i.e. genomic sequence, protein, metabolite, and microbiome information) with clinical information and health outcomes to optimize disease diagnosis, treatment and prevention specific to each patient. Successful implementation of precision health requires interprofessional collaboration, community outreach efforts, and coordination of care, a mission that nurses are well-positioned to lead. Despite the surge of interest and attention to precision health, most nurses are not well-versed in precision health or its implications for the nursing profession. Based on a critical analysis of literature and expert opinions, this paper provides an overview of precision health and the importance of engaging the nursing profession for its implementation. Other topics reviewed in this paper include big data and omics, information science, integration of family health history in precision health, and nursing omics research in symptom science. The paper concludes with recommendations for nurse leaders in research, education, clinical practice, nursing administration and policy settings for which to develop strategic plans to implement precision health
Biomarkers as Common Data Elements for Symptom and Selfâ Management Science
PurposeBiomarkers as common data elements (CDEs) are important for the characterization of biobehavioral symptoms given that once a biologic moderator or mediator is identified, biologically based strategies can be investigated for treatment efforts. Just as a symptom inventory reflects a symptom experience, a biomarker is an indicator of the symptom, though not the symptom per se. The purposes of this position paper are to (a) identify a â minimum setâ of biomarkers for consideration as CDEs in symptom and selfâ management science, specifically biochemical biomarkers; (b) evaluate the benefits and limitations of such a limited array of biomarkers with implications for symptom science; (c) propose a strategy for the collection of the endorsed minimum set of biologic samples to be employed as CDEs for symptom science; and (d) conceptualize this minimum set of biomarkers consistent with National Institute of Nursing Research (NINR) symptoms of fatigue, depression, cognition, pain, and sleep disturbance.Design and MethodsFrom May 2016 through January 2017, a working group consisting of a subset of the Directors of the NINR Centers of Excellence funded by P20 or P30 mechanisms and NINR staff met bimonthly via telephone to develop this position paper suggesting the addition of biomarkers as CDEs. The full group of Directors reviewed drafts, provided critiques and suggestions, recommended the minimum set of biomarkers, and approved the completed document. Best practices for selecting, identifying, and using biological CDEs as well as challenges to the use of biological CDEs for symptom and selfâ management science are described. Current platforms for sample outcome sharing are presented. Finally, biological CDEs for symptom and selfâ management science are proposed along with implications for future research and use of CDEs in these areas.FindingsThe recommended minimum set of biomarker CDEs include proâ and antiâ inflammatory cytokines, a hypothalamicâ pituitaryâ adrenal axis marker, cortisol, the neuropeptide brainâ derived neurotrophic factor, and DNA polymorphisms.ConclusionsIt is anticipated that this minimum set of biomarker CDEs will be refined as knowledge regarding biologic mechanisms underlying symptom and selfâ management science further develop. The incorporation of biological CDEs may provide insights into mechanisms of symptoms, effectiveness of proposed interventions, and applicability of chosen theoretical frameworks. Similarly, as for the previously suggested NINR CDEs for behavioral symptoms and selfâ management of chronic conditions, biological CDEs offer the potential for collaborative efforts that will strengthen symptom and selfâ management science.Clinical RelevanceThe use of biomarker CDEs in biobehavioral symptoms research will facilitate the reproducibility and generalizability of research findings and benefit symptom and selfâ management science.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143764/1/jnu12378.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/143764/2/jnu12378_am.pd
Dielectric relaxations in PEEK by combined dynamic dielectric spectroscopy and thermally stimulated current
The molecular dynamics of a quenched poly (ether ether ketone) (PEEK) was studied over a broad frequency range from 10-3 to 106 Hz by combining dynamic dielectric spectroscopy (DDS) and thermo-stimulated current (TSC) analysis. The dielectric relaxation losses e00 KK has been determined from the real part e0 T(x) thanks to KramersâKronig transform. In this way, conduction and relaxation processes can be analyzed independently. Two secondary dipolar relaxations, the c and the b modes, corresponding to non-cooperative localized molecular mobility have been pointed out. The main a relaxation appeared close to the glass transition temperature as determined by DSC; it has been attributed to the delocalized cooperative mobility of the free amorphous phase. The relaxation times of dielectric relaxations determined with TSC at low frequency converge with relaxation times extracted from DDS at high frequency. This correlation emphasized continuity of mobility kinetics between vitreous and liquid state. The dielectric spectroscopy exhibits the ac relaxation, near 443 K, which has been associated with the rigid amorphous phase confined by crystallites. This present experiment demonstrates coherence of the dynamics of the PEEK heterogeneous amorphous phase between glassy and liquid state and significantly improve the knowledge of molecular/dynamic structure relationships
Reproductive inequality in humans and other mammals
To address claims of human exceptionalism, we determine where humans fit within the greater mammalian distribution of reproductive inequality. We show that humans exhibit lower reproductive skew (i.e., inequality in the number of surviving offspring) among males and smaller sex differences in reproductive skew than most other mammals, while nevertheless falling within the mammalian range. Additionally, female reproductive skew is higher in polygynous human populations than in polygynous nonhumans mammals on average. This patterning of skew can be attributed in part to the prevalence of monogamy in humans compared to the predominance of polygyny in nonhuman mammals, to the limited degree of polygyny in the human societies that practice it, and to the importance of unequally held rival resources to womenâs fitness. The muted reproductive inequality observed in humans appears to be linked to several unusual characteristics of our speciesâincluding high levels of cooperation among males, high dependence on unequally held rival resources, complementarities between maternal and paternal investment, as well as social and legal institutions that enforce monogamous norms
Tryptophan degradation in women with breast cancer: a pilot study
<p>Abstract</p> <p>Background</p> <p>Altered tryptophan metabolism and indoleamine 2,3-dioxygenase activity are linked to cancer development and progression. In addition, these biological factors have been associated with the development and severity of neuropsychiatric syndromes, including major depressive disorder. However, this biological mechanism associated with both poor disease outcomes and adverse neuropsychiatric symptoms has received little attention in women with breast cancer. Therefore, a pilot study was undertaken to compare levels of tryptophan and other proteins involved in tryptophan degradation in women with breast cancer to women without cancer, and secondarily, to examine levels in women with breast caner over the course of chemotherapy.</p> <p>Findings</p> <p>Blood samples were collected from women with a recent diagnosis of breast cancer (<it>n </it>= 33) before their first cycle of chemotherapy and after their last cycle of chemotherapy. The comparison group (<it>n </it>= 24) provided a blood sample prior to breast biopsy. Plasma concentrations of tryptophan, kynurenine, and tyrosine were determined. The kynurenine to tryptophan ratio (KYN/TRP) was used to estimate indoleamine 2,3-dioxygenase activity. On average, the women with breast cancer had lower levels of tryptophan, elevated levels of kynurenine and tyrosine and an increased KYN/TRP ratio compared to women without breast cancer. There was a statistically significant difference between the two groups in the KYN/TRP ratio (<it>p </it>= 0.036), which remained elevated in women with breast cancer throughout the treatment trajectory.</p> <p>Conclusions</p> <p>The findings of this pilot study suggest that increased tryptophan degradation may occur in women with early-stage breast cancer. Given the multifactorial consequences of increased tryptophan degradation in cancer outcomes and neuropsychiatric symptom manifestation, this biological mechanism deserves broader attention in women with breast cancer.</p
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