433 research outputs found

    Cancer and Stem Cell Biology: How Tightly Intertwined?

    Get PDF
    Ever since the discovery of cancer stem cells in leukemia and, more recently, in solid tumors, enormous attention has been paid to the apparent stem cell nature of cancer. These concepts were the focus of the “Stem Cells and Cancer” symposium held recently at the University of California, San Francisco, and the inspiration for this overview of current research and important questions emerging in this area

    Evidence for a large off-centered galactic outflow and its connection to the extraplanar diffuse ionized gas in IC 1553

    Full text link
    Aims. We analyze a MUSE optical integral field spectrum of the star-forming edge-on galaxy IC 1553 in order to study its extraplanar diffuse ionized gas (eDIG) and the processes shaping its disk-halo interface. Methods. We extracted the optical emission line properties from the integral field spectrum and generated the commonly used emission line diagnostic diagrams in order to analyze the ionization conditions and the distribution of the eDIG. Furthermore, we performed gravitational potential fitting to investigate the kinematics of a suspected galactic outflow. Results. We find that the eDIG scale height has a maximum value of approximately 1.0 kpc and decreases roughly linearly with the radial distance from the galactic center in projection. The ionization state of the eDIG is not consistent with a pure photoionization scenario and instead requires a significant contribution from shock ionization. This, in addition to the gas kinematics, strongly suggests the presence of a galactic scale outflow, the origin of which lies at least 1.4 kpc away from the galactic center. The inferred shock velocity in the eDIG of approximately 225 km s-1 is comparable to the escape velocity estimated from our potential modelling. The asymmetric distribution of currently star-forming clusters produces a range of different ionization conditions in the eDIG. As a result, the vertical emission line profiles vary quantitatively and qualitatively along the major axis of the galaxy. This analysis illustrates that it is crucial in studies of the eDIG to use observations that take the spatial and kinematical distributions into account, such as those done with integral field units, to form an accurate picture of the relevant physical properties.Comment: Accepted for publication by Astronomy & Astrophysics on August 1, 202

    Heads will roll! Routes to effective trust repair in the aftermath of a CEO transgression

    Get PDF
    CEO transgressions are a common storyline in today's business press. Such incidents result in the need to repair trust for both the CEO and the organisation that the CEO leads. Existing empirical research on trust repair has focused primarily on interpersonal trust, resulting in a body of knowledge that provides many insights to the errant CEO but few insights for those who aim to repair trust in the organisation. Since organisations also need to regain the trust of stakeholders after a CEO transgression, research on organisational trust repair is clearly warranted. Organisations have options for trust repair that are not available to individuals (e.g. dismissing the transgressor), these actions may be initiated by parties other than the culpable party (e.g. the Board of Directors), and the mechanisms underlying organisational versus interpersonal trust repair may differ. However, trust in CEOs and their associated organisations may also be intertwined since the CEO is the symbolic representative of the organisation. To better understand how organisations and CEOs can repair trust in the aftermath of a CEO transgression, we conduct a scenario experiment examining two tactics that are commonly used in practice: CEO dismissal, and CEO apology + penance. We also examine the proposed underlying mechanisms of perceived repentance and perceived disentitativity. Results indicate that both tactics can influence trust in the CEO as well as the organisation, and that perceived repentance and perceived disentitativity mediate the effects of Board responses on trust in the CEO but not on trust in the organisation

    Evaluation of a community-based hypertension improvement program (ComHIP) in Ghana: data from a baseline survey.

    Get PDF
    BACKGROUND: Ghana faces an increasing burden of non-communicable disease with rates of hypertension estimated as high as 36% in adults. Despite these high rates, hypertension control remains very poor in Ghana (4%). The current project aims to implement and evaluate a community-based programme to raise awareness, and to improve treatment and control of hypertension in the Eastern Region of Ghana. In this paper, we present the findings of the baseline cross-sectional survey focusing on hypertension prevalence, awareness, treatment, and control. METHODS: To evaluate the ComHIP project, a quasi-experimental design consisted of a before and after evaluations are being implemented in the intervention and comparison districts. A cohort study component is being implemented in the intervention district to assess hypertension control. Background anthropometric and clinical data collected as part of the baseline survey were analyzed in STATA Version 11. We examined the characteristics of individuals, associated with the baseline study outcomes using logistic regression models. RESULTS: We interviewed 2400 respondents (1200 each from the comparison and intervention districts), although final sample sizes after data cleaning were 1170 participants in the comparison district and 1167 in the intervention district. With the exception of ethnicity, the control and intervention districts compare favorably. Overall 32.4% of the study respondents were hypertensive (31.4% in the control site; and 33.4% in the intervention site); 46.2% of hypertensive individuals were aware of a previous diagnosis of hypertension (44.7% in the control site, and 47.7% in the intervention site), and only around 9% of these were being treated in either arm. Hypertension control was 1.3% overall (0.5% in the comparison site, and 2.1% in the intervention site). Age was a predictor of having hypertension, and so was increasing body mass index (BMI), waist, and hip circumferences. After adjusting for age, the risk factors with the greatest association with hypertension were being overweight (aOR = 2.30; 95% CI 1.53-3.46) or obese (aOR = 3.61; 95% CI 2.37-5.51). Older individuals were more likely to be aware of their hypertension status than younger people. After adjusting for age people with a family history of hypertension or CVD, or having an unhealthy waist hip ratio, were more likely to be aware of their hypertension status. CONCLUSIONS: The high burden of hypertension among the studied population, coupled with high awareness, yet very low level of hypertension treatment and control requires in-depth investigation of the bottlenecks to treatment and control. The low hypertension treatment and control rates despite current and previous general educational programs particularly in the intervention district, may suggest that such programs are not necessarily impactful on the health of the population

    Evaluation of the Smart Work Zone Speed Notification System

    Get PDF
    The Smart Work Zone Speed Notification (SWZSN) system aims to alleviate congestion, queuing, and rear end crashes in work zones by informing drivers of the speed of the downstream segment using a type of portable Intelligent Lane Control System (ILCS), Portable Changeable Message Signs (PCMS). The hypothesis was that drivers, knowing the speed up to 1 mile downstream, will slow down early or at least be alert and perform smoother decelerations. Video of the SWZSN was analyzed over two years of operation by the Minnesota Traffic Observatory. Overall, the system resulted in beneficial reductions of selected decelerations by the drivers. In situations where the messages communicated to the drivers were consistent and accurate, reductions of more than 30% in the selected deceleration rates were observed. Unfortunately, there were several cases where counterproductive or misleading messages were communicated to the drivers, prompting relative increases to the selected deceleration rates. The most important observation, stemming from both positive and negative influences, was that the speed notification system was noticed by drivers and resulted in a statistically significant influence on driving behavior, unlike other driver alert systems

    Target prediction and a statistical sampling algorithm for RNA-RNA interaction

    Get PDF
    It has been proven that the accessibility of the target sites has a critical influence for miRNA and siRNA. In this paper, we present a program, rip2.0, not only the energetically most favorable targets site based on the hybrid-probability, but also a statistical sampling structure to illustrate the statistical characterization and representation of the Boltzmann ensemble of RNA-RNA interaction structures. The outputs are retrieved via backtracing an improved dynamic programming solution for the partition function based on the approach of Huang et al. (Bioinformatics). The O(N6)O(N^6) time and O(N4)O(N^4) space algorithm is implemented in C (available from \url{http://www.combinatorics.cn/cbpc/rip2.html})Comment: 7 pages, 10 figure

    Cancer stem cells in gliomas: identifying and understanding the apex cell in cancer’s hierarchy.

    Get PDF
    ABSTRACT Neuro-oncology research has rediscovered a complexity of nervous system cancers through the incorporation of cellular heterogeneity into tumor models with cellular subsets displaying stem-cell characteristics. Self-renewing cancer stem cells (CSCs) can propagate tumors and yield nontumorigenic tumor bulk cells that display a more differentiated phenotype. The ability to prospectively isolate and interrogate CSCs is defining molecular mechanisms responsible for the tumor maintenance and growth. The clinical relevance of CSCs has been supported by their resistance to cytotoxic therapies and their promotion of tumor angiogenesis. Although the field of CSC biology is relatively young, continued elucidation of the features of these cells holds promise for the development of novel patient therapies.

    Silence Speaks Volumes: The Effectiveness of Reticence in Comparison to Apology and Denial for Repairing Integrity- and Competence-Based Trust Violations

    Get PDF
    Prior research on responses to trust violations has focused primarily on the effects of apology and denial. The authors extended this research by studying another type of verbal response that is often used to respond to trust violations but has not been considered in the trust literature: reticence. An accused party may use reticence in a sincere and even legitimate attempt to persuade a trustor to withhold judgment. Yet, by considering information diagnosticity and belief formation mechanisms through which verbal responses influence trust, the authors argue that reticence is a suboptimal response because it combines the least effective elements of apology and denial. Specifically, reticence is a suboptimal response to an integrity violation because, like apology, it fails to address guilt. And reticence is a suboptimal response to a competence violation because, like denial, it fails to signal redemption. Results from 2 laboratory studies, simulating different contexts and using research participants from 2 different countries, provide support for the prediction. The results offer important implications for those who might use reticence to respond to a perceived trust violation and also for those who must judge another's reticence

    Repairing Trust with Individuals vs. Groups

    Get PDF
    ► We investigate how trust repair might differ with groups vs. individuals. ► Repairing trust is generally more difficult with groups than individuals. ► Both individuals and groups trust less after denying low competence or apologizing for low integrity. ► But the relative difficulty of trust repair w/ groups vs. individuals also depends on interaction. ► Ensuing group assessments affect initial individual assessments but not the reverse. This study incorporates insights from research on group decision-making and trust repair to investigate the differences that arise when alleged transgressors attempt to regain the trust of groups as compared to individuals. Results indicate that repairing trust is generally more difficult with groups than individuals, and both groups and individuals were less trusting when trustees denied culpability (rather than apologized) for a competence-based violation or apologized (rather than denied culpability) for an integrity-based violation. However, the interaction of violation-type and violation-response also ultimately affected the relative difficulty of repairing trust with groups vs. individuals, with the greater harshness of groups dissipating when the transgressors’ responses were effectively matched with the type of violation. Persuasive argumentation rather than normative pressure, furthermore, mediated these differences. Thus, the sequencing of individual vs. group assessments mattered, such that subsequent group assessments affected initial individual assessments but not the reverse
    corecore