778 research outputs found
Three geographically separate domestications of Asian rice
Domesticated rice (Oryza sativa L.) accompanied the dawn of Asian civilization(1) and has become one of world's staple crops. From archaeological and genetic evidence various contradictory scenarios for the origin of different varieties of cultivated rice have been proposed, the most recent based on a single domestication(2,3). By examining the footprints of selection in the genomes of different cultivated rice types, we show that there were three independent domestications in different parts of Asia. We identify wild populations in southern China and the Yangtze valley as the source of the japonica gene pool, and populations in Indochina and the Brahmaputra valley as the source of the indica gene pool. We reveal a hitherto unrecognized origin for the aus variety in central India or Bangladesh. We also conclude that aromatic rice is a result of a hybridization between japonica and aus, and that the tropical and temperate versions of japonica are later adaptations of one crop. Our conclusions are in accord with archaeological evidence that suggests widespread origins of rice cultivation(1,4). We therefore anticipate that our results will stimulate a more productive collaboration between genetic and archaeological studies of rice domestication, and guide utilization of genetic resources in breeding programmes aimed at crop improvement.European Research Council [339941]info:eu-repo/semantics/publishedVersio
Habitat Utilization and Movement Ecology of Black Bears in Cherokee National Forest
Home range, movements, and habitat use of black bears in the Cherokee National Forest were monitored from June 1980 through December 1981.
In 1980, home range sizes averaged 192 km2 for male bears and 23 km2 for females, whereas the average range in 1981 for males was 60 km2 and 15 km2 for females. Larger ranges for males likely reflect a social structure that enhances reproduction. Differences in home range sizes between years was attributed to the availability and abundance of hard mast, especially acorns. Both sexes exhibited seasonal shifts in range use between summer and fall. Males traveled greater distances between summer and fall ranges than female bears.
Diel movements were affected by time of year, different foraging strategies between seasons, and mating activities. Both sexes moved greater distances in diurnal periods than nocturnal periods. Nocturnal movements were extensive only during fall. Increased nocturnal movements in fall were associated with seasonal changes in food sources, preparation for denning, and the influence of human-related activities.
Bears exhibited crepuscular patterns of activity that were modified seasonally. Activities of bears were affected by weather factors, distribution and availability of foods, seasonal changes in foraging strategies, and denning. Sex, age, and reproductive classes also affected activity patterns. Adult male bears were the most active group, whereas females with cubs were the least active. The pattern of activity for bears in the CNF suggests that breeding may occur in early August.
Factors affecting habitat use included season, individual behavioral differences among bears, reproductive classes, and variations in hard mast production between years. Occurrence of bears in hardwoods increased significantly during 1980 when acorns and hickory nuts were scarce.
Habitat preference was also determined by a utilization-availability analysis. Hardwoods were preferred, although some variations in habitat use were sex related. Male bears used hardwoods (chiefly oaks) more than expected in terms of their availability, whereas females occurred more than expected in softwoods (chiefly pines)
Diabetes (db/db) mutation-induced endometrial epithelial lipoapoptosis: Ultrastructural and cytochemical analysis of reproductive tract atrophy
BACKGROUND: The diabetes (db/db) mutation in C57BL/KsJ mice promotes a progressive cytolipidemia within the endometrial epithelial (EE) layer of the female reproductive tract which results in premature cellular and organ atrophy. The current studies focus on the ultrastructural and cytochemical changes which promote nuclear apoptosis and cytostructural disruption following the expression of endometrial hypercytolipidemia which promotes diabetes-associated organoinvolution and manifest infertility. METHODS: Control (normal:+/+) and diabetes (db/db) genotype groups were prepared for high resolution light microscopic analysis of cytolipidemia and nuclear apoptosis (TUNEL-labeled 3'-DNA fragmentation) indices and compared to the transmission electron (TEM) microscopic analysis of endometrial tissue samples collected from 8–16 week-old groups. RESULTS: Compared to controls, db/db mutation expression induced a dramatic increase in EE cytolipid vacuole volume and density within the epithelial endometrial layer. TEM analysis revealed that cytolipid vacuole accumulations initially aggregated at the baso-polar regions of UEE cells in response to the systemic hyperglycemic/hypertriglyceridemic conditions which characterized the (db/db) groups. Progressive cytoplasmic movement of the lipid pools into perinuclear compartments of affected EE cells induced nuclear isolation from organelles that were displaced towards peripheral cytoplasmic compartments. Cytochemical analysis of lipid vacuole accumulations indicated attraction towards, and incorporation within, the nuclear envelope of hyperlipidemic cells. Co-localization of nuclear apoptotic 3'-DNA fragments within identified hyperlipidemic EE cells was coincident with the cytochemical and ultrastructural identification of lipid penetration through the nuclear envelope in db/db mutants. CONCLUSION: These results are the first cytochemical indication that the metabolic disturbances in db/db mutants which promote hypercytolipidemia are coincident with lipoapoptosis-induced nuclear dissolution, as denoted by DNA fragmentation analysis. The lipidemia-induced alterations in intracellular organelle and nuclear architectures suggests that the metabolic disturbances in glucose and lipid metabolic cascades in diabetes (db/db) mutants disrupts cytointegrity, culminating in nuclear disregulation (as indicated by lipoapoptosis) and eventual premature reproductive tract organoinvolution and resultant, manifest, reproductive sterility
Influences of obese (ob/ob) and diabetes (db/db) genotype mutations on lumber vertebral radiological and morphometric indices: Skeletal deformation associated with dysregulated systemic glucometabolism
BACKGROUND: Both diabetes and obesity syndromes are recognized to promote lumbar vertebral instability, premature osteodegeneration, exacerbate progressive osteoporosis and increase the propensity towards vertebral degeneration, instability and deformation in humans. METHODS: The influences of single-gene missense mutations, expressing either diabetes (db/db) or obese (ob/ob) metabolic syndromes on vertebral maturation and development in C57BL/KsJ mice were evaluated by radiological and macro-morphometric analysis of the resulting variances in osteodevelopment indices relative to control parameters between 8 and 16 weeks of age (syndrome onset @ 4 weeks), and the influences of low-dose 17-B-estradiol therapy on vertebral growth expression evaluated. RESULTS: Associated with the indicative genotypic obesity and hyper-glycemic/-insulinemic states, both db/db and ob/ob mutants demonstrated a significant (P ≤ 0.05) elongation of total lumbar vertebrae column (VC) regional length, and individual lumbar vertebrae (LV1-5) lengths, relative to control VC and LV parameters. In contrast, LV1-5 width indices were suppressed in db/db and ob/ob mutants relative to control LV growth rates. Between 8 and 16 weeks of age, the suppressed LV1-5 width indices were sustained in both genotype mutant groups relative to control osteomaturation rates. The severity of LV1-5 width osteosuppression correlated with the severe systemic hyperglycemic and hypertriglyceridemic conditions sustained in ob/ob and db/db mutants. Low-dose 17-B-estradiol therapy (E2-HRx: 1.0 ug/ 0.1 ml oil s.c/3.5 days), initiated at 4 weeks of age (i.e., initial onset phase of db/db and ob/ob expressions) re-established control LV 1–5 width indices without influencing VC or LV lengths in db/db groups. CONCLUSION: These data demonstrate that the abnormal systemic endometabolic states associated with the expression of db/db and ob/ob genomutation syndromes suppress LV 1–5 width osteomaturation rates, but enhanced development related VC and LV length expression, relative to control indices in a progressive manner similar to recognized human metabolic syndrome conditions. Therapeutic E2 modulation of the hyperglycemic component of diabetes-obesity syndrome protected the regional LV from the mutation-induced osteopenic width-growth suppression. These data suggest that these genotype mutation models may prove valuable for the evaluation of therapeutic methodologies suitable for the treatment of human diabetes- or obesity-influenced, LV degeneration-linked human conditions, which demonstrate amelioration from conventional replacement therapies following diagnosis of systemic syndrome-induced LV osteomaturation-associated deformations
Putting the Patient Back in Patient Care: Health Decision-Making from the Patient’s Perspective
This research explored health decision-making processes among people recently diagnosed with type 2 diabetes. Our analysis suggested that diagnosis with type 2 was followed by a period of intense emotional and cognitive disequilibrium. Subsequently, the informants were observed to proceed to health decision-making which was affected by three separate and interrelated factors: knowledge, self-efficacy, and purpose. Knowledge included cognitive or factual components and emotional elements. Knowledge influenced the degree of upset or disequilibrium the patient experienced, and affected a second category, agency: the informants’ confidence in their ability to enact lifestyle changes. The third factor, purpose, summarized the personal and deeply held reasons people gave as they made decisions concerning their health, eating and exercising. We propose this model, grounded in informant stories, as a heuristic, to guide further inquiry. From these stories, the patient is seen as more active and the interrelated influences of knowledge, agency, and purpose, synergistically interact to explain changes in health behaviors
TRANSformation; Affecting Transgender Prejudice in the Classroom
Social discrimination is a common experience with measurable consequences for those affected. The effects include poorer mental health and poverty, issues which are commonly addressed by human service professionals. People who are transgender are particular targets of discrimination and, as such, find themselves in need of human service assistance at levels disproportionate to the larger population. Research from social psychology suggests that intergroup contact reduces prejudice. This quasi-experiment explored the effect a transgender speaker, followed by informal social interaction, had on measures of transgender prejudice in a sample of college student
Modification of the Haag-Streit design slit-labp biomicroscope for ocular photography of the anterior and posterior segments
Modification of the Haag-Streit design slit-labp biomicroscope for ocular photography of the anterior and posterior segment
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An Emerging Model of Creative Game-based Learning
We consider the integration of creative approaches to problem solving into pervasive games is a natural extension of play for creative thinking – one that can innovatively drive technology-led changes to the facilitation of creative thinking and pose a new genre in serious gaming for learning. This paper presents an initial proposal of a new model of creative game-base learning (CGBL), which emerged through mapping of established characteristics of climates that encourage creativity and innovation to characteristics of effective serious games
iBusy: Research on children, families, and smartphones
Within the past 10 years, mobile devices have been widely adopted by adults and are now present in the lives of almost all U.S. children. While phones are common, our understanding of what effect this technology has upon children\u27s development is lagging. Bioecological theory and attachment theory suggest that this new technology may be disruptive, especially to the degree to which it interferes with the parent-child relationship. This article reflects a National Organization for Human Services conference presentation and shares preliminary results from semi-structured interviews conducted with 18 youth, ages 7 through 11. Only four of eighteen interviewees voiced any negative thoughts concerning their parents’ use of mobile devices. However, those who reported feeling ignored by their parents experienced the negative emotions deeply. Themes that emerged from analysis of transcripts included devices as tools and boundaries
Directed evolution of a magnetic resonance imaging contrast agent for noninvasive imaging of dopamine
The development of molecular probes that allow in vivo imaging of neural signaling processes with high temporal and spatial resolution remains challenging. Here we applied directed evolution techniques to create magnetic resonance imaging (MRI) contrast agents sensitive to the neurotransmitter dopamine. The sensors were derived from the heme domain of the bacterial cytochrome P450-BM3 (BM3h). Ligand binding to a site near BM3h's paramagnetic heme iron led to a drop in MRI signal enhancement and a shift in optical absorbance. Using an absorbance-based screen, we evolved the specificity of BM3h away from its natural ligand and toward dopamine, producing sensors with dissociation constants for dopamine of 3.3–8.9 μM. These molecules were used to image depolarization-triggered neurotransmitter release from PC12 cells and in the brains of live animals. Our results demonstrate the feasibility of molecular-level functional MRI using neural activity–dependent sensors, and our protein engineering approach can be generalized to create probes for other targets.Charles A. Dana Foundation. Brain and Immuno-ImagingRaymond and Beverley Sackler FoundationNational Institutes of Health (U.S.) (grant R01-DA28299)National Institutes of Health (U.S.) (grant DP2-OD2441)National Institutes of Health (U.S.) (grant R01-GM068664)Jacobs Institute for Molecular Engineering for Medicine. Jacobs Institute for Molecular Engineering for MedicineNational Institutes of Health (U.S.) (grant R01-DE013023
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