119 research outputs found
Examining the Association of Trait-like vs. In-Vivo Catastrophizing and Experimental Pain Sensitivity
Catastrophizing cognitions, consisting of rumination, helplessness, and magnification, are associated with increased pain intensity and pain behaviors in individuals with chronic pain. Trait-like catastrophizing refers to levels of catastrophizing related to general past pain experiences. In-vivo catastrophizing refers to levels of catastrophizing related to a specific pain event, usually one that has just occurred. The current study examined the extent to which trait-like and in-vivo pain catastrophizing are differentially related to experimental pain tolerance. We hypothesized that: 1) In-vivo catastrophizing would have a stronger relationship with pain tolerance than trait-like catastrophizing. 2) Different components of catastrophizing (i.e. rumination, helplessness, and magnification) would be differentially related to pain tolerance.This study was supported by the Department of Psychology Research Award
Combining Phylogeography with Distribution Modeling: Multiple Pleistocene Range Expansions in a Parthenogenetic Gecko from the Australian Arid Zone
Phylogenetic and geographic evidence suggest that many parthenogenetic organisms have evolved recently and have spread rapidly. These patterns play a critical role in our understanding of the relative merits of sexual versus asexual reproductive modes, yet their interpretation is often hampered by a lack of detail. Here we present a detailed phylogeographic study of a vertebrate parthenogen, the Australian gecko Heteronotia binoei, in combination with statistical and biophysical modeling of its distribution during the last glacial maximum. Parthenogenetic H. binoei occur in the Australian arid zone and have the widest range of any known vertebrate parthenogen. They are broadly sympatric with their sexual counterparts, from which they arose via hybridization. We have applied nested clade phylogeographic, effective migration, and mismatch distribution analyses to mitochondrial DNA (mtDNA) sequences obtained for 319 individuals sampled throughout the known geographic ranges of two parthenogenetic mitochondrial lineages. These analyses provide strong evidence for past range expansion events from west to east across the arid zone, and for continuing eastward range expansion. Parthenogen formation and range expansion events date to the late Pleistocene, with one lineage expanding from the northwest of its present range around 240,000 years ago and the second lineage expanding from the far west around 70,000 years ago. Statistical and biophysical distribution models support these inferences of recent range expansion, with suitable climatic conditions during the last glacial maximum most likely limited to parts of the arid zone north and west of much of the current ranges of these lineages. Combination of phylogeographic analyses and distribution modeling allowed considerably stronger inferences of the history of this complex than either would in isolation, illustrating the power of combining complementary analytical approaches
Treatment-Mediated Alterations in HIV Fitness Preserve CD4+ T Cell Counts but Have Minimal Effects on Viral Load
For most HIV-infected patients, antiretroviral therapy controls viral replication. However, in some patients drug resistance can cause therapy to fail. Nonetheless, continued therapy with a failing regimen can preserve or even lead to increases in CD4+ T cell counts. To understand the biological basis of these observations, we used mathematical models to explain observations made in patients with drug-resistant HIV treated with enfuvirtide (ENF/T-20), an HIV-1 fusion inhibitor. Due to resistance emergence, ENF was removed from the drug regimen, drug-sensitive virus regrown, and ENF was re-administered. We used our model to study the dynamics of plasma-viral RNA and CD4+ T cell levels, and the competition between drug-sensitive and resistant viruses during therapy interruption and re-administration. Focusing on resistant viruses carrying the V38A mutation in gp41, we found ENF-resistant virus to be 17±3% less fit than ENF-sensitive virus in the absence of the drug, and that the loss of resistant virus during therapy interruption was primarily due to this fitness cost. Using viral dynamic parameters estimated from these patients, we show that although re-administration of ENF cannot suppress viral load, it can, in the presence of resistant virus, increase CD4+ T cell counts, which should yield clinical benefits. This study provides a framework to investigate HIV and T cell dynamics in patients who develop drug resistance to other antiretroviral agents and may help to develop more effective strategies for treatment
A genealogy of hacking
Hacking is now a widely discussed and known phenomenon, but remains difficult to define and empirically identify because it has come to refer to many different, sometimes incompatible, material practices. This paper proposes genealogy as a framework for understanding hacking by briefly revisiting Foucault’s concept of genealogy and interpreting its perspectival stance through the feminist materialist concept of the situated observer. Using genealogy as a theoretical frame a history of hacking will be proposed in four phases. The first phase is the ‘pre-history’ of hacking in which four core practices were developed. The second phase is the ‘golden age of cracking’ in which hacking becomes a self-conscious identity and community and is for many identified with breaking into computers, even while non-cracking practices such as free software mature. The third phase sees hacking divide into a number of new practices even while old practices continue, including the rise of serious cybercrime, hacktivism, the division of Open Source and Free Software and hacking as an ethic of business and work. The final phase sees broad consciousness of state-sponsored hacking, the re-rise of hardware hacking in maker labs and hack spaces and the diffusion of hacking into a broad ‘clever’ practice. In conclusion it will be argued that hacking consists across all the practices surveyed of an interrogation of the rationality of information techno-cultures enacted by each hacker practice situating itself within a particular techno-culture and then using that techno-culture to change itself, both in changing potential actions that can be taken and changing the nature of the techno-culture itself
Mouth cancer: presentation, detection and referral in primary dental care
Mouth cancer can present as a variety of abnormalities and visible changes affecting the oral mucosa, including ulceration, swelling and areas of erythema. The five-year survival from mouth cancer is poor at approximately 50%. Detection of the cancer while less than 2 cm in diameter with no metastasis greatly improves the outcome for the patient. Although many cancers in the mouth develop from what was previously an apparently normal mucosa, some arise in pre-existing conditions that are therefore regarded as potentially malignant. Regular assessment of the soft tissues within the mouth and the neck for the presence of abnormalities is an essential component of primary dental care. Any persistent and unexplained abnormality requires referral for definitive diagnosis and specialist management
Assessing managerial power theory: A meta-analytic approach to understanding the determinants of CEO compensation
Although studies about the determinants of CEO compensation are ubiquitous, the balance of
evidence for one of the more controversial theoretical approaches, managerial power theory,
remains inconclusive. The authors provide a meta-analysis of 219 U.S.-based studies, focusing
on the relationships between indicators of managerial power and levels of CEO compensation
and CEO pay-performance sensitivities. The results indicate that managerial power theory is
well equipped for predicting core compensation variables such as total cash and total
compensation but less so for predicting the sensitivity of pay to performance. In most situations
where CEOs are expected to have power over the pay setting process, they receive significantly
higher levels of total cash and total compensation. In contrast, where boards are expected to
have more power, CEOs receive lower total cash and total compensation. In addition, powerful
directors also appear to be able to establish tighter links between CEO compensation and firm
performance and can accomplish this even in the face of powerful CEOs. The authors discuss
the implications for theory and research regarding the determinants of executive compensation
Aquaporins: important but elusive drug targets.
The aquaporins (AQPs) are a family of small, integral membrane proteins that facilitate water transport across the plasma membranes of cells in response to osmotic gradients. Data from knockout mice support the involvement of AQPs in epithelial fluid secretion, cell migration, brain oedema and adipocyte metabolism, which suggests that modulation of AQP function or expression could have therapeutic potential in oedema, cancer, obesity, brain injury, glaucoma and several other conditions. Moreover, loss-of-function mutations in human AQPs cause congenital cataracts (AQP0) and nephrogenic diabetes insipidus (AQP2), and autoantibodies against AQP4 cause the autoimmune demyelinating disease neuromyelitis optica. Although some potential AQP modulators have been identified, challenges associated with the development of better modulators include the druggability of the target and the suitability of the assay methods used to identify modulators
Law, Environment, and the “Nondismal” Social Sciences
Over the past 30 years, the influence of economics over the study of environmental law and policy has expanded considerably, becoming in the process the predominant framework for analyzing regulations that address pollution, natural resource use, and other environmental issues. This review seeks to complement the expansion of economic reasoning and methodology within the field of environmental law and policy by identifying insights to be gleaned from various “nondismal” social sciences. In particular, three areas of inquiry are highlighted as illustrative of interdisciplinary work that might help to complement law and economics and, in some cases, compensate for it: the study of how human individuals perceive, judge, and decide; the observation and interpretation of how knowledge schemes are created, used, and regulated; and the analysis of how states and other actors coordinate through international and global regulatory regimes. The hope is to provide some examples of how environmental law and policy research can be improved by deeper and more diverse engagement with social science
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
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