429 research outputs found
Anxiety, Stress, Depression, and Patients’ Responses to Periodontal Treatment: Periodontists’ Knowledge and Professional Behavior
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142063/1/jper0064.pd
The Money To Get Started - What Do Farm Boys Expect?
It takes a lot of capital to acquire and to operate an Iowa farm. The study of occupational plans and preferences of Iowa farm boys helps to indicate just how much influence capital needs have on their plans
Occupational plans of Iowa farm boys
This bulletin reports the findings of an exploratory study of the long-range occupational plans of Iowa farm boys in their senior year of high school. The primary objectives of the study were: (1) to relate the theory of choice to occupational planning, (2) to describe the occupational plans of the boys, (3) to determine the characteristics which differentiate boys who plan to farm from boys who plan nonfarm careers and (4) to appraise the relative importance of factors influencing farm-nonfarm occupational plans.
Application of the theory of choice to occupational planning resulted in three general hypotheses to explain why some farm boys plan to farm while others plan nonfarm occupations. These hypotheses involved individual differences in (1) occupational satisfaction functions (preference systems), (2) available resources and (3) the results expected from using given resources in farm and nonfarm employments. Various operational hypotheses derived from the general hypotheses were evaluated on the basis of evidence obtained from a state-wide sample of senior farm boys attending Iowa high schools in rural areas and cities under 25,000 population in the spring of 1959
What Careers for Farm Boys?
This is the first of a series of articles reporting the results of a study of the career preferences and plans and choices of farm boys. This article tells of career plans the boys made and of their immediate after high school plans
Cascading effects of canopy mortality drive long-term changes in understorey diversity in temperate old-growth forests of Europe
Questions: We investigated the influence of protracted mortality of a dominant canopy tree (Abies alba) on long-term understorey dynamics. We ask (a) how tree regeneration and understorey species diversity and composition changed over 32 years; and (b) whether the observed changes were mainly driven by mortality of A. alba.
Location: Three old-growth forest reserves dominated by A. alba and Fagus sylvatica in the Dinaric Mountains of Slovenia.
Method: Tree layer and understorey regeneration and herbs were surveyed in 147 plots across the three forest reserves in 1983 and 2015. Soils were also sampled in 2015. The study period coincides with a protracted period of increased A. alba mortality in the canopy layer associated with anthropogenic emissions.
Results: Between 1983 and 2015, the decline in canopy layer A. alba caused a recruitment pulse of F. sylvatica regeneration to the subcanopy tree layer across the three reserves. These changes were accompanied by a significant decline in plot level herb species richness. A model-based analysis of beta-diversity revealed significant community convergence during the study period, mainly caused by the loss of rare species. Ellenberg values indicate that these changes were mainly driven by loss of understorey light, while an increase in soil pH may have played a role also.
Conclusions: This observational study suggests that the long-term decline of A. alba resulted in a cascade of processes - widespread F. sylvatica recruitment that impeded penetration of light to the forest floor, and possibly a change in soil conditions due to the decline of coniferous litter. These changes caused a significant loss of herb diversity and homogenization of the understorey community across the three sites. This study sheds light on the potential cascading consequences triggered by episodes of increased tree mortality resulting from global-change-type drivers
A dinucleotide deletion in the ankyrin promoter alters gene expression, transcription initiation and TFIID complex formation in hereditary spherocytosis
Ankyrin defects are the most common cause of hereditary spherocytosis (HS). In some HS patients, mutations in the ankyrin promoter have been hypothesized to lead to decreased ankyrin mRNA synthesis. The ankyrin erythroid promoter is a member of the most common class of mammalian promoters which lack conserved TATA, initiator or other promoter cis elements and have high G+C content, functional Sp1 binding sites and multiple transcription initiation sites. We identified a novel ankyrin gene promoter mutation, a TG deletion adjacent to a transcription initiation site, in a patient with ankyrin-linked HS and analyzed its effects on ankyrin expression. In vitro, the mutant promoter directed decreased levels of gene expression, altered transcription initiation site utilization and exhibited defective binding of TATA-binding protein (TBP) and TFIID complex formation. In a transgenic mouse model, the mutant ankyrin promoter led to abnormalities in gene expression, including decreased expression of a reporter gene and altered transcription initiation site utilization. These data indicate that the mutation alters ankyrin gene transcription and contributes to the HS phenotype by decreasing ankyrin gene synthesis via disruption of TFIID complex interactions with the ankyrin core promoter. These studies support the model that in promoters that lack conserved cis elements, the TFIID complex directs preinitiation complex formation at specific sites in core promoter DNA and provide the first evidence that disruption of TBP binding and TFIID complex formation in this type of promoter leads to alterations in start site utilization, decreased gene expression and a disease phenotype in viv
Modelamiento de susceptibilidad a movimientos en masa producto de lluvias intensas a nivel nacional, estudio final
El presente estudio propone el desarrollo de un mapa de susceptibilidad a movimientos en masa producto de lluvias intensas en el territorio peruano y proporciona una herramienta de gestión del territorio para la mitigación de eventos de remoción en masa potencialmente desastrosos. Para ello, se ha realizado un trabajo sistemático, que ha permitido recopilar datos in situ de los movimientos en masa producto de las lluvias intensas, que han servido para el ajuste y validación de un modelo de predicción de probabilidad de ocurrencia del evento de remoción en masa producto de lluvias intensas mediante técnicas de aprendizaje automático (machine learning) usando el algoritmo de bosques aleatorios (Random Forest)
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