171 research outputs found

    The Contours of Extraterritorial Jurisdiction in Drug Smuggling Cases

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    This note examines the contours of U.S. jurisdiction over drug smugglers on the high seas. After a brief discussion of the two principal U.S. drug statutes, the note considers the territorial and protective principles of jurisdiction as defined by U.S. courts. Controversy currently centers around whether U.S. drug laws apply to foreign ships, carrying controlled substances on the high seas, where there has been no showing of an intent to import the drugs into the United States

    The Role of Faculty Mentoring in Improving Retention and Completion Rates for Historically Underrepresented STEM Students

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    There is a growing recognition of the need for science, technology, engineering, and mathematics (STEM) workers who provide diverse perspectives enabling companies to keep up with the demands of the 21st -century workforce. Creating a diverse workforce requires improving access to STEM education for historically underrepresented students, including low-income students and first-generation students. However, significant challenges and barriers exist. The purpose of this paper is to showcase an innovative approach to mentoring historically underrepresented STEM students which integrates photovoice and photo-elicitation. This new approach in mentoring takes student participation one step further by asking students to document and share their lived experiences through photographs (e.g., photovoice). Then, photo-elicitation is used to further engage students in discussing what led to their subsequent empowerment in leveraging successes or overcoming barriers. The study was conducted with 19 participants who were primarily American Indian students attending a small college in Wisconsin, USA. The findings suggest students benefited from the mentoring program and perceived it as an enriching learning experience which aided in goal development, accountability, and an opportunity to learn more about strategies for student success. The implementation of this new approach and the results gathered from this study are important as they may inform educational leaders and postsecondary institutions serving historically underrepresented STEM students on supports and strategies that could be carried out on their campuses

    Clinical ROC Studies of Digital Stereo Mammography

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    The objective of this study was to explore and document the diagnostic utility of digital stereo mammography for the detection of localized breast cancer in women. In it we character­ized the ability of experienced mammographers, general radiologists, and non-radiologists to detect three types of tumor masses embedded within a heterogeneous background of normal tis­sue elements in numerically simulated digital mammograms. The simulated mammograms were displayed to the subjects on a high resolution video display, both in stereo mode and in mono mode. Half of the mammograms contained a single tumor, ranging from 0.3 to 0.8 cm in maxi­mal diameter. Each reader rated 120 images (60 in stereo and 60 in mono) as to the probability of abnormality on scale of 1-5. Observer responses were evaluated using receiver operating characteristic (ROC) analysis to characterize any difference in diagnostic performance between the two viewing modes. The synthesized mammograms and the digital display were highly rated by the participant radiologists as promising tools for future research. The results of ROC analysis, however, indicated no significant difference in tumor detection when the same readers utilized the stereo mode versus the mono mode (Az mono = 0.833 versus, Az stereo = 0.826). The results were similar for readers of all 3 experience levels--mammographers, general radiolo­gists, and non-radiologists

    Thrombospondin mediates migration and potentiates platelet-derived growth factor-dependent migration of calf pulmonary artery smooth muscle cells

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    A precipitating factor in the development of atherosclerotic lesions is the inappropriate migration and proliferation of vascular smooth muscle cells (SMC) within the intima of the vessel wall. Focusing on the role of extracellular matrix proteins in SMC migration, we have demonstrated that thrombospondin (TSP) itself is a potent modulator of SMC motility and acts to potentiate platelet-derived growth factor (PDGF)-mediated SMC migration as well. Migration of SMC to TSP was dose dependent. Interestingly, maximal SMC migration to TSP exceeded that to either PDGF or basic fibroblast growth factor (bFGF). The distal COOH terminus of TSP was shown to mediate SMC migration as demonstrated by complete inhibition of the response by monoclonal antibody (mAb) C6.7. Nevertheless, proteolytic fragments of TSP were not as potent as intact TSP in mediating SMC migration. Only by combining the heparin-binding domain (HBD) with the 140 kD COOH terminal fragment was SMC migration restored to levels seen with intact TSP. Based on antibody inhibition studies, an Α v -containing integrin receptor, but not Α v Β 1 or Α v Β 3 , appeared to be involved in SMC migration to TSP. The coincidental expression of PDGF and TSP at sites of vascular injury and inflammation led us to evaluate the effect of suboptimal levels of TSP on SMC responsiveness to PDGF. SMC migration in response to PDGF was enhanced nearly 60% in the presence of suboptimal concentrations of TSP. This effect was specific for PDGF and dependent on the concentration of TSP with maximal potentiation obtained between 50–100 nM TSP, concentrations tenfold lower than those necessary for SMC migration to TSP itself. mAb C6.7 completely inhibited enhancement but, as with SMC migration to TSP alone, TSP proteolytic fragments did not possess the effectiveness of the intact molecule. Additional experiments assessing SMC migration to PDGF demonstrated that PDGF stimulated SMC motility indirectly by inducing TSP synthesis. These studies suggested that TSP functions as an autocrine motility factor to modulate SMC migration, which in conjunction with PDGF could serve to aggravate and accelerate development of atherosclerotic lesions at sites of vascular injury or inflammation. © 1993 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/49886/1/1041570104_ftp.pd

    Pulsed Electromagnetic Field Stimulates Cellular Proliferation in Human Intervertebral Disc Cells

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    ∙The authors have no financial conflicts of interest. Purpose: The purpose of this study is to investigate the mechanism of cellular proliferation of electromagnetic field (EMF) on human intervertebral disc (IVD) cells. Materials and Methods: Human IVD cells were cultured three-dimensionally in alginate beads. EMF was exposed to IVD cells with 650 Ϊ, 1.8 millitesla magnetic flux density, 60 Hz sinusoidal wave. Cultures were divided into a control and EMF group. Cytotoxicity, DNA synthesis and proteoglycan synthesis were measured by MTT assay, [ 3 H]-thymidine, and [ 35 S]-sulfate incorporation. To detect phenotypical expression, reverse transcription-polymerase chain reactions (RT-PCR) were performed for aggrecan, collagen type I, and type II mRNA expression. To assess action mechanism of EMF, IVD cells were exposed to EMF with N G-Monomethyl-L-arginine (NMMA) and acetylsalicylic acid (ASA). Results: There was no cytotoxicity in IVD cells with the EMF group in MTT assay. Cellular proliferation was observed in the EMF group (p < 0.05). There was no difference in newl

    Health literacy, dementia knowledge and perceived utility of digital health modalities among future health professionals

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    Objectives: Studies of dementia knowledge (including dementia risk reduction) in health-care trainees highlight varying levels of understanding across countries and disciplines. This draws attention to the need for a well-trained health workforce with the knowledge to champion and implement such strategies. This study (a) assessed dementia knowledge and health literacy among a sample of Australian health-care students, (b) identified modality preferences of digital health interventions addressing dementia prevention and (c) examined potential relationships among health literacy, dementia knowledge, dementia prevention knowledge and a student's preferences for different digital health modalities. Methods: A cross-sectional survey assessed dementia knowledge and health literacy in 727 health students across 16 Australian universities representing both metropolitan and regional cohorts. The All Aspects of Health Literacy Scale and the Dementia Knowledge Assessment Scale were administered. Questions about the perceived effectiveness of strategies and preferred digital health modalities for dementia prevention/risk reduction were asked. Results: The students had relatively high health literacy scores. However, dementia knowledge and evidence-based dementia prevention knowledge were average. Only 7% claimed knowledge of available dementia-related digital health interventions. Associations among health literacy, dementia knowledge and dementia prevention, with recommendations for different digital modalities, are presented. Conclusions: Health-related degrees need to increase dementia knowledge, health literacy and knowledge of effective dementia-related digital health interventions. It is imperative to equip the future health workforce amid an ageing population with increased dementia rates and where evidence-based digital health interventions will increasingly be a source of support

    Human disc cells in monolayer vs 3D culture: cell shape, division and matrix formation

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    BACKGROUND: The relationship between cell shape, proliferation, and extracellular matrix (ECM) production, important aspects of cell behavior, is examined in a little-studied cell type, the human annulus cell from the intervertebral disc, during monolayer vs three-dimensional (3D) culture. RESULTS: Three experimental studies showed that cells respond specifically to culture microenvironments by changes in cell shape, mitosis and ECM production: 1) Cell passages showed extensive immunohistochemical evidence of Type I and II collagens only in 3D culture. Chondroitin sulfate and keratan sulfate were abundant in both monolayer and 3D cultures. 2) Cells showed significantly greater proliferation in monolayer in the presence of platelet-derived growth factor compared to cells in 3D. 3) Cells on Matrigel™-coated monolayer substrates became rounded and formed nodular colonies, a finding absent during monolayer growth. CONCLUSIONS: The cell's in vivo interactions with the ECM can regulate shape, gene expression and other cell functions. The shape of the annulus cell changes markedly during life: the young, healthy disc contains spindle shaped cells and abundant collagen. With aging and degeneration, many cells assume a strikingly different appearance, become rounded and are surrounded by unusual accumulations of ECM products. In vitro manipulation of disc cells provides an experimental window for testing how disc cells from given individuals respond when they are grown in environments which direct cells to have either spindle- or rounded-shapes. In vitro assessment of the response of such cells to platelet-derived growth factor and to Matrigel™ showed a continued influence of cell shape even in the presence of a growth factor stimulus. These findings contribute new information to the important issue of the influence of cell shape on cell behavior

    Impact of direct cell co-cultures on human adipose-derived stromal cells and nucleus pulposus cells

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    Biologic and cellular treatment strategies aiming for curing intervertebral disc degeneration (IDD) have been proposed recently. Given the convenient availability and expansion potential, adipose-derived stromal cells (ADSCs) might be an ideal cell candidate. However, the interaction between ADSCs and nucleus pulposus (NP) cells still remains ambiguous, especially in direct co-cultures of the two types of cells. Nevertheless, NP markers in ADSCs after co-cultures were unidentified. Here, we addressed the interaction of human ADSCs and NP cells in a direct co-culture system for the first time. As a result, ADSCs could differentiate to the NP cell phenotype with a significant up-regulated expression of multiple genes and proteins in extracellular matrix (ECM) (SOX9, COL2A1, ACAN, and COL6A2), relative NP markers (FOXF1, PAX1, CA12, and HBB) and pertinent growth factors (CDMP-1, TGF-beta1, IGF-1, and CTGF). Moreover, the gene expression of COL2A1, ACAN, and COL6A2 of degenerate NP cells was also up-regulated. Collectively, these results suggest that direct co-cultures of ADSCs and NP cells may exert a reciprocal impact, that is, both stimulating ADSCs differentiation to the NP cell phenotype and inducing NP cells to regain functional phenotype. Accordingly, ADSCs might be a potential candidate in the development of cellular treatment strategies for IDD.published_or_final_versio
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