187 research outputs found
The petrofabrics of aufeis in a turbulent Alaskan stream
Thesis (M.S.) University of Alaska Fairbanks, 1969The growth, form, and decay of ice in turbulent Goldstream Creek, Alaska, has been observed each year since 1964. Overflows which occur throughout the early part of the winter deposit layers of ice (aufeis) upon the pre-existing ice surface. Vertical and horizontal thin sections of the stream ice from the years 1965-66, 1966-67, and 1967-68 were examined and photographed under ordinary and polarized light. The c-axes of the crystals were oriented with a Rigsby four-axis stage and plotted on Schmidt equal-area nets. Examination of photographs and stereograms revealed five basic types of ice in Goldstream Creek: (1) clear, massive, original stream ice composed of elongate, tapered crystals in which the c-axes are primarily horizontal and randomly oriented; (2) bubbly overflow ice layers (aufeis) with horizontal c-axes which are sometimes aligned parallel to the stream flow; (3) skim ice layers with vertical to horizontal c-axis crystals; (4) fine-grained equigranular snow ice; and (5) underwater ice masses of slightly coherent, rounded plates with the c-axes normal to the plates and randomly oriented. During break-up the melt-water flows on top of the stream ice and slowly erodes the ice layers in the stream by a combination of melting and mechanical fragmentation. The layers are eroded away in descending order from the top to the bottom of the stream
Variables affecting the probability of complete fusion of the medial clavicular epiphysis
In this study, we have combined data on clavicle fusion from different studies and applied a binomial logistic regression analysis. As such, we aimed to assess whether or not variables such as sex, socioeconomic status, and ethnicity influence the probability of having mature, i.e., completely fused clavicles at a given age. We further explored whether the method of clavicle examination, i.e., diagnosis from either a dry bone specimen, an examination of X-rays, or an examination of computed tomography scans, affects the probability of being diagnosed with mature clavicles. It appeared that only ethnicity did not significantly affect this probability. Finally, we illustrated how the logit model may be used to predict the probability of being diagnosed with mature clavicles
Toward optimal implementation of cancer prevention and control programs in public health: A study protocol on mis-implementation
Abstract Background Much of the cancer burden in the USA is preventable, through application of existing knowledge. State-level funders and public health practitioners are in ideal positions to affect programs and policies related to cancer control. Mis-implementation refers to ending effective programs and policies prematurely or continuing ineffective ones. Greater attention to mis-implementation should lead to use of effective interventions and more efficient expenditure of resources, which in the long term, will lead to more positive cancer outcomes. Methods This is a three-phase study that takes a comprehensive approach, leading to the elucidation of tactics for addressing mis-implementation. Phase 1: We assess the extent to which mis-implementation is occurring among state cancer control programs in public health. This initial phase will involve a survey of 800 practitioners representing all states. The programs represented will span the full continuum of cancer control, from primary prevention to survivorship. Phase 2: Using data from phase 1 to identify organizations in which mis-implementation is particularly high or low, the team will conduct eight comparative case studies to get a richer understanding of mis-implementation and to understand contextual differences. These case studies will highlight lessons learned about mis-implementation and identify hypothesized drivers. Phase 3: Agent-based modeling will be used to identify dynamic interactions between individual capacity, organizational capacity, use of evidence, funding, and external factors driving mis-implementation. The team will then translate and disseminate findings from phases 1 to 3 to practitioners and practice-related stakeholders to support the reduction of mis-implementation. Discussion This study is innovative and significant because it will (1) be the first to refine and further develop reliable and valid measures of mis-implementation of public health programs; (2) bring together a strong, transdisciplinary team with significant expertise in practice-based research; (3) use agent-based modeling to address cancer control implementation; and (4) use a participatory, evidence-based, stakeholder-driven approach that will identify key leverage points for addressing mis-implementation among state public health programs. This research is expected to provide replicable computational simulation models that can identify leverage points and public health system dynamics to reduce mis-implementation in cancer control and may be of interest to other health areas
Burning out physical and emotional fatigue : evaluating the effects of a progamme aimed at reducing burnout amongst mental health nurses
Burnout is a common problem among mental health nurses. High levels of burnout result in job dissatisfaction, rapid turnover of staff, physical and psychological discomfort, and a reduction in the quality of patient care. While there is an abundance of research relating to burnout per se, research regarding the impact of burnout prevention programmes is lacking. This study aimed to measure the effects of a burnout prevention programme on mental health nurses working in Saudi Arabia (SA). A quasi-experimental design was used to test the effectiveness of a two-day burnout prevention workshop. The sample consisted of an intervention group (n=154) and a control group (n=142). Data collected using the Maslach Burnout Inventory (MBI) measured the effects of the workshop at one, three and six month intervals after completion of the programme. Data were analysed using the latest version of SPSS. Means, standard deviations, frequencies and percentages were used to describe the sample and levels of burnout. A t-test, ANOVA, Multiple linear regression and chi squared were used to measure the effect of the workshop before and at the three time points after exposure. Findings indicate the program was effective with a significant reduction being reported one month after the intervention. However, although not returning to baseline scores, burnout scores had increased at six months. In conclusion, while the overall efficacy of the burnout reduction program is evident, mental health nurses would benefit from having opportunity to use some of the strategies on a regular basis
Influences of mentoring functions on job satisfaction and organizational commitment of graduate employees
Abstract: A significant percentage of the workforce, within the construction sector is nearing retirement age over the next ten years. These employees have acquired a tremendous amount of knowledge about how things work, how to get things done and who to go to when problems arise. Losing their expertise and experience could significantly reduce efficiency, resulting in costly mistakes, unexpected quality problems, or significant disruptions in services and or performance. The business world has long known and relied upon mentoring as a proven technique for developing in house talent. Previous studies proved that the implementation of mentoring programme is beneficial for enhancing employee skills and attitudes. Few researchers are devoted to exploring the impact. This paper is aimed at examining the effects of mentoring functions on the job satisfaction and organizational commitment of new graduates in the South African construction industry..
Comparison of MRI and VQ-SPECT as a screening test for patients with suspected CTEPH: CHANGE-MRI study design and rationale
The diagnostic strategy for chronic thromboembolic pulmonary hypertension (CTEPH) is composed of two components required for a diagnosis of CTEPH: the presence of chronic pulmonary embolism and an elevated pulmonary artery pressure. The current guidelines require that ventilation–perfusion single-photon emission computed tomography (VQ-SPECT) is used for the first step diagnosis of chronic pulmonary embolism. However, VQ-SPECT exposes patients to ionizing radiation in a radiation sensitive population. The prospective, multicenter, comparative phase III diagnostic trial CTEPH diagnosis Europe - MRI (CHANGE-MRI, ClinicalTrials.gov identifier NCT02791282) aims to demonstrate whether functional lung MRI can serve as an equal rights alternative to VQ-SPECT in a diagnostic strategy for patients with suspected CTEPH. Positive findings are verified with catheter pulmonary angiography or computed tomography pulmonary angiography (gold standard). For comparing the imaging methods, a co-primary endpoint is used. (i) the proportion of patients with positive MRI in the group of patients who have a positive SPECT and gold standard diagnosis for chronic pulmonary embolism and (ii) the proportion of patients with positive MRI in the group of patients with negative SPECT and gold standard. The CHANGE-MRI trial will also investigate the performance of functional lung MRI without i.v. contrast agent as an index test and identify cardiac, hemodynamic, and pulmonary MRI-derived parameters to estimate pulmonary artery pressures and predict 6–12 month survival. Ultimately, this study will provide the necessary evidence for the discussion about changes in the recommendations on the diagnostic approach to CTEPH
MR imaging in sports-related glenohumeral instability
Sports-related shoulder pain and injuries represent a common problem. In this context, glenohumeral instability is currently believed to play a central role either as a recognized or as an unrecognized condition. Shoulder instabilities can roughly be divided into traumatic, atraumatic, and microtraumatic glenohumeral instabilities. In athletes, atraumatic and microtraumatic instabilities can lead to secondary impingement syndromes and chronic damage to intraarticular structures. Magnetic resonance (MR) arthrography is superior to conventional MR imaging in the diagnosis of labro-ligamentous injuries, intrinsic impingement, and SLAP (superior labral anteroposterior) lesions, and thus represents the most informative imaging modality in the overall assessment of glenohumeral instability. This article reviews the imaging criteria for the detection and classification of instability-related injuries in athletes with special emphasis on the influence of MR findings on therapeutic decisions
Multicenter standardization of phase-resolved functional lung MRI in patients with suspected chronic thromboembolic pulmonary hypertension
Background
Detection of pulmonary perfusion defects is the recommended approach for diagnosing chronic thromboembolic pulmonary hypertension (CTEPH). This is currently achieved in a clinical setting using scintigraphy. Phase-resolved functional lung (PREFUL) magnetic resonance imaging (MRI) is an alternative technique for evaluating regional ventilation and perfusion without the use of ionizing radiation or contrast media.
Purpose
To assess the feasibility and image quality of PREFUL-MRI in a multicenter setting in suspected CTEPH.
Study Type
This is a prospective cohort sub-study.
Population
Forty-five patients (64 ± 16 years old) with suspected CTEPH from nine study centers.
Field Strength/Sequence
1.5 T and 3 T/2D spoiled gradient echo/bSSFP/T2 HASTE/3D MR angiography (TWIST).
Assessment
Lung signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared between study centers with different MRI machines. The contrast between normally and poorly perfused lung areas was examined on PREFUL images. The perfusion defect percentage calculated using PREFUL-MRI (QDPPREFUL) was compared to QDP from the established dynamic contrast-enhanced MRI technique (QDPDCE). Furthermore, QDPPREFUL was compared between a patient subgroup with confirmed CTEPH or chronic thromboembolic disease (CTED) to other clinical subgroups.
Statistical Tests
t-Test, one-way analysis of variance (ANOVA), Pearson's correlation. Significance level was 5%.
Results
Significant differences in lung SNR and CNR were present between study centers. However, PREFUL perfusion images showed a significant contrast between normally and poorly perfused lung areas (mean delta of normalized perfusion −4.2% SD 3.3) with no differences between study sites (ANOVA: P = 0.065). QDPPREFUL was significantly correlated with QDPDCE (r = 0.66), and was significantly higher in 18 patients with confirmed CTEPH or CTED (57.9 ± 12.2%) compared to subgroups with other causes of PH or with excluded PH (in total 27 patients with mean ± SD QDPPREFUL = 33.9 ± 17.2%).
Data Conclusion
PREFUL-MRI could be considered as a non-invasive method for imaging regional lung perfusion in multicenter studies.
Level of Evidence
3
Technical Efficacy
Stage
Peripheral Digit Ischemic Syndrome Can Be a Manifestation of Postoperative Thrombotic Thrombocytopenic Purpura
In addition to common dysfunction of the brain and kidney, thrombotic thrombocytopenic purpura (TTP) may present with atypical clinical features due to the involvement of other organs such as the lung, pancreas, heart, eye, and skin. We have also observed the unusual presentation of peripheral digit ischemic syndrome (PDIS) in some patients with postoperative TTP To clarify this relationship between TTP and PDIS, the hematologic data from the medical records of patients with known diagnoses of thrombotic microangiopathy (TM) were examined in a single institution. A total of 94 patients were diagnosed with TM. Among these patients, PDIS developed in six patients and in all these patients PDIS occurred with postoperative TTP Four patients also had acute respiratory distress syndrome (ARDS). Because of delayed diagnosis of TTP, only two patients survived and four died. One patient responded to plasma exchange and survived, and another patient recovered from postoperative TTP without plasma exchange. However, both patients required the amputation of multiple digits. In conclusion, PDIS is another atypical manifestation of TTP and has occurred exclusively in patients with postoperative TTP in this series. Once PDIS developed, the prognosis was poor and amputation of digits was needed in surviving patients. Early recognition of this atypical manifestation of TTP is essential for a favorable outcome
Características del liderazgo pedagógico del directivo docente de la I.E. de Jesús del municipio de Concordia
Esta investigación abordó el liderazgo pedagógico, específicamente el liderazgo directivo, su papel dentro del proceso pedagógico de la institución educativa está justificado por la relevancia que tiene en la gestión curricular, entre otras funciones, pues permite que las instituciones educativas - I.E marchen adecuadamente y alcancen mayores logros para todos los estudiantes. El objetivo consistió en identificar las características del liderazgo pedagógico del directivo docente de la I.E de Jesús del municipio de Concordia. Para esto se consideró una investigación enmarcada dentro del enfoque cualitativo de tipo descriptivo, el método fue estudio de caso. Los instrumentos que se utilizaron fueron, la entrevista, el diario de campo y el grupo focal. Con base en los resultados obtenidos en las entrevistas se destacan aspectos importantes de la comunicación y el liderazgo, vinculados a la gestión administrativa de la I.E. La investigación muestra la importancia que tiene el liderazgo pedagógico del directivo docente como elemento clave en el desarrollo y funcionamiento pedagógico-curricular de la I.E.This research addressed pedagogical leadership, such as one that focuses on the directive role, specifically on his role in the educational process on the educative institution; the relevance it's justified for this process for function properly on the institutions to and achieve greater achievements for all students. The objective was to identify the pedagogical leadership from the educative director of the Educative Institution of Jesus from the Concordia municipality. For this, was considered an investigation framed within the qualitative approach of descriptive type, the method was a study case. The instruments used were interview, field diaries and focus group. Based on the interview results obtained, important aspects of communication and leadership were highlighted, linked to the development processes on the educative institution. The research shows the importance on a pedagogical leadership of the teaching director as a key element within the institution.Magíster en EducaciónMaestrí
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