221 research outputs found
Associations among Habitat Destruction, Infant Care, and Male Activity in San Martin Titi Monkeys (Plecturocebus oenanthe) of Peru
The San Martin titi monkey (Plecturocebus oenanthe) is a Critically Endangered Neotropical
primate endemic to Peru, where forested habitat has been dramatically altered due to
anthropogenic activities. In the face of ongoing habitat destruction, research is urgently needed
on the ability of P. oenanthe to persist in disturbed environments. Prior research has indicated
that titi monkeys are able to adapt behaviorally to disturbed habitats, however such studies have
addressed such flexibility regarding general activities (e.g. traveling) only. This study aimed to
clarify whether level of habitat destruction is related to variation in: 1) infant care; 2) conflict
between caregivers and infants; and 3) male activity budgets. I habituated two P. oenanthe
groups and assigned relative levels of habitat destruction per site by comparing forest fragment
and home range size (and loss per season), logging rate, canopy cover, tree density, tree basal
area, tree height, and fruit availability. Along with two field assistants, I observed study subjects
over two field seasons. We conducted focal follows of four infants using instantaneous sampling
to track: 1) the percentage of care provided by age and sex class, which included male, maternal,
adult (male and maternal care), alloparental (sibling), and total care (all care combined); 2)
caregiver-infant conflict; and 3) the activity budgets of males while caring for infants. I predicted
that level of habitat destruction would reduce infant care (except by siblings), increase caregiverinfant conflict, and lead males to adopt a time-minimizing strategy in response to habitat
destruction. I analyzed infant care and male activity budgets using generalized linear mixed
models. I assessed conflict data qualitatively by comparing average, minimum, and maximum
values. In support of care predictions, greater habitat destruction was associated with reduced
male care and increased alloparental care. Contradicting my prediction, maternal care increased
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with habitat destruction. Maternal and alloparental care compensated for reduced male care at the
higher destruction site. As expected, conflict increased with greater habitat destruction and the
male experiencing greater habitat destruction reduced energetically-costly activities. The stark
variation in caregiving, conflict, and male activity across sites indicates a substantial degree of
flexibility in P. oenanthe infant care
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The relationship of student involvement and multicultural comfort among student government members as compared with the student population at Oregon State University
The purpose of this study was to investigate the level of social interaction and social comfort among five undergraduate ethnic groups: African American, American Indian, Asian American, Caucasian American, and Hispanic American. Another purpose was to explore the correlation between the level of social contact and comfort among the five ethnic groups. The sample included 141 full-time, continuing undergraduate and graduate students at Oregon State University. The contact scale included items measuring the number of acquaintances, frequency of
interaction, positive degree of feeling, number of friends, and duration of contact.
The comfort scale was a modified version of Byrnes and Kiger's (1988) Social Scale. It asked respondents to rate from one (very uncomfortable) to seven (very comfortable) their comfort with people of different ethnicity in six roles: president of the United States, counselor, professor, a small group member in a classroom setting or co-curricular activity, a roommate, or a date. T-tests of variance compared information about ethnicity. Pearson correlation coefficients were also used to
explore the relationship between contact and comfort. Regression analysis and chisquare
procedures were also performed for more detailed analysis on contact, comfort, and demographic scales. Results of the study demonstrated that involvement in Associated Student Government at Oregon State University was consistent with increased contact levels
between students in the five ethnic groups. There were, however, no significant increases in comfort across ethnic lines. All groups were most comfortable with their identified ethnic group
Intentional and unintentional nonadherence to hydroxyurea among people with sickle cell disease: A qualitative study
Hydroxyurea is an efficacious treatment for sickle cell disease (SCD), but adoption is low among individuals with SCD. The objective of this study was to examine barriers to patients' adherence to hydroxyurea use regimens by using the intentional and unintentional medication nonadherence framework. We interviewed individuals with SCD age 15 to 49.9 years who were participants in the Sickle Cell Disease Implementation Consortium (SCDIC) Needs Assessment. The intentional and unintentional medication nonadherence framework explains barriers to using hydroxyurea and adds granularity to the understanding of medication adherence barriers unique to the SCD population. In total, 90 semi-structured interviews were completed across 5 of the 8 SCDIC sites. Among interviewed participants, 57.8% (n = 52) were currently taking hydroxyurea, 28.9% (n = 26) were former hydroxyurea users at the time of the interview, and 13.3% (n = 12) had never used hydroxyurea but were familiar with the medication. Using a constructivist grounded theory approach, we discovered important themes that contributed to nonadherence to hydroxyurea, which were categorized under unintentional (eg, Forgetfulness, External Influencers) and intentional (Negative Perceptions of Hydroxyurea, Aversion to Taking Any Medications) nonadherence types. Participants more frequently endorsed adherence barriers that fell into the unintentional nonadherence type (70%) vs intentional nonadherence type (30%). Results from this study will help SCD health care providers understand patient choices and decisions as being either unintentional or intentional, guide tailored clinical discussions regarding hydroxyurea therapy, and develop specific, more nuanced interventions to address nonadherence factors
Quantum Cryptography
Quantum cryptography is a new method for secret communications offering the
ultimate security assurance of the inviolability of a Law of Nature. In this
paper we shall describe the theory of quantum cryptography, its potential
relevance and the development of a prototype system at Los Alamos, which
utilises the phenomenon of single-photon interference to perform quantum
cryptography over an optical fiber communications link.Comment: 36 pages in compressed PostScript format, 10 PostScript figures
compressed tar fil
Warren McCulloch and the British cyberneticians
Warren McCulloch was a significant influence on a number of British cyberneticians, as some British pioneers in this area were on him. He interacted regularly with most of the main figures on the British cybernetics scene, forming close friendships and collaborations with several, as well as mentoring others. Many of these interactions stemmed from a 1949 visit to London during which he gave the opening talk at the inaugural meeting of the Ratio Club, a gathering of brilliant, mainly young, British scientists working in areas related to cybernetics. This paper traces some of these relationships and interaction
Uptake of antibiotics and their toxicity to lettuce following routine irrigation with contaminated water in different soil types
To address the issue of global freshwater shortages, wastewater has become an increasingly valuable alternative for crop irrigation. As a result, trace levels of emerging contaminants, including antibiotics, may occur in water used for food production. The objective of this study was to investigate how soil texture affected the availability and uptake of three chemically diverse antibiotics (lincomycin, oxytetracycline, and sulfamethoxazole) by lettuce grown in soils comprised of silt clay and increasing percentages of sand. Lettuce was irrigated routinely with antibiotic-amended water (1 mg/L) from seed germination through the first harvest (40 days), switched to control water, and fate monitored at days 45 and 50. Sulfamethoxazole was the only compound where tissue concentrations increased with increasing sand concentrations to 24.7 ng/g fresh weight (FW). Lincomycin was most readily accumulated with increasing concentrations observed at the second harvest in both the loam (68.3 ng/g FW) and sandy soils (66.6 ng/g FW). Apparent toxicity of the antibiotic mixture resulted in decreasing plant mass (37-72%) with increasing sand content. Results from this study show that soil texture impacts plant growth, contaminant transport, plant uptake, and toxic effects, which all contribute to, observed concentrations in edible plant portions
Retrograde Amnesia in Dementia: Comparison of HIV-Associated Dementia, Alzheimer's Disease, and Huntington's Disease.
Dysregulated Fc gamma receptor-mediated phagocytosis pathway in Alzheimer’s disease: network-based gene expression analysis
Transcriptomics has become an important tool for identification of biological pathways dysregulated in Alzheimer's disease (AD). We performed a network-based gene expression analysis of blood-based microarray gene expression profiles using 2 independent cohorts, Alzheimer's Disease Neuroimaging Initiative (ADNI; N = 661) and AddNeuroMed (N = 674). Weighted gene coexpression network analysis identified 17 modules from ADNI and 13 from AddNeuroMed. Four of the modules derived in ADNI were significantly related to AD; 5 modules in AddNeuroMed were significant. Gene-set enrichment analysis of the AD-related modules identified and replicated 3 biological pathways including the Fc gamma receptor-mediated phagocytosis pathway. Module-based association analysis showed the AD-related module, which has the 3 pathways, to be associated with cognitive function and neuroimaging biomarkers. Gene-based association analysis identified PRKCD in the Fc gamma receptor-mediated phagocytosis pathway as being significantly associated with cognitive function and cerebrospinal fluid biomarkers. The identification of the Fc gamma receptor-mediated phagocytosis pathway implicates the peripheral innate immune system in the pathophysiology of AD. PRKCD is known to be related to neurodegeneration induced by amyloid-β
Information homeostasis as a fundamental principle governing the cell division and death
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