388 research outputs found
Small world effects in evolution
For asexual organisms point mutations correspond to local displacements in
the genotypic space, while other genotypic rearrangements represent long-range
jumps. We investigate the spreading properties of an initially homogeneous
population in a flat fitness landscape, and the equilibrium properties on a
smooth fitness landscape. We show that a small-world effect is present: even a
small fraction of quenched long-range jumps makes the results indistinguishable
from those obtained by assuming all mutations equiprobable. Moreover, we find
that the equilibrium distribution is a Boltzmann one, in which the fitness
plays the role of an energy, and mutations that of a temperature.Comment: 13 pages and 5 figures. New revised versio
Multiple right-sided pulmonary nodules: metastatic cancer or resectable early stage tumor?
The aim of this paper is to focus attention on complex cases of lung disease that may benefit from being managed outside formal guidelines. A 52 year-old man who had previously undergone a laryngectomy for squamous cell carcinoma, presented with a 1.2 cm nodule in the right upper pulmonary lobe. Three months later a new CT scan found that the nodule had slightly increased in size and also detected two new smaller nodules in the middle lobe. A PET/CT scan showed metabolic hyperactivity of all nodules. Since needle aspiration of the upper one revealed malignant cells, the patient was considered to be suffering from metastatic cancer and started on chemotherapy. At follow-up both CT and PET scans found a significant reduction in volume and activity of the lower nodules but no change in the upper one. At diagnostic thoracoscopy, histology demonstrated that the upper nodule was an adenocarcinoma while the lower ones were inflammatory. An upper lobectomy and systematic nodal dissection were therefore performed. Histology established a diagnosis of upper pulmonary adenocarcinoma and sarcoidosis. Our report suggests that in complicated oncologic cases in which non-invasive diagnostic tools yield incongruous results surgery should be considered without delay
Clinical and Experimental Applications of NIR-LED Photobiomodulation
This review presents current research on the use of far-red to near-infrared (NIR) light treatment in various in vitro and in vivo models. Low-intensity light therapy, commonly referred to as “photobiomodulation,” uses light in the far-red to near-infrared region of the spectrum (630–1000 nm) and modulates numerous cellular functions. Positive effects of NIR–light-emitting diode (LED) light treatment include acceleration of wound healing, improved recovery from ischemic injury of the heart, and attenuated degeneration of injured optic nerves by improving mitochondrial energy metabolism and production. Various in vitro and in vivo models of mitochondrial dysfunction were treated with a variety of wavelengths of NIR-LED light. These studies were performed to determine the effect of NIR-LED light treatment on physiologic and pathologic processes. NIRLED light treatment stimulates the photoacceptor cytochrome c oxidase, resulting in increased energy metabolism and production. NIR-LED light treatment accelerates wound healing in ischemic rat and murine diabetic wound healing models, attenuates the retinotoxic effects of methanol-derived formic acid in rat models, and attenuates the developmental toxicity of dioxin in chicken embryos. Furthermore, NIR-LED light treatment prevents the development of oral mucositis in pediatric bone marrow transplant patients. The experimental results demonstrate that NIR-LED light treatment stimulates mitochondrial oxidative metabolism in vitro, and accelerates cell and tissue repair in vivo. NIR-LED light represents a novel, noninvasive, therapeutic intervention for the treatment of numerous diseases linked to mitochondrial dysfunction
“You're in a World of Chaos”: Experiences Accessing HIV Care and Adhering to Medications After Incarceration
Most HIV-infected inmates leave prison with a suppressed viral load; many, however, become disconnected from care and non-adherent to medications during reentry to community life. In this secondary data analysis of focus groups (N = 6) and in-depth interviews (N = 9) with 46 formerly incarcerated HIV-infected people during reentry, we used an inductive analytic approach to explore the interplay between individual, interpersonal, community, and structural factors and HIV management. Participants described barriers and facilitators to care engagement and adherence at each of these 4 levels, as well as a milieu of HIV and incarceration-related stigma and discrimination. The constellation of barriers and facilitators created competing demands and a sense of chaos in participants’ lives, which led them to address reentry-related basic needs (e.g., housing, food) before health care needs. Interventions that simultaneously address multiple levels, including augmenting employment and housing opportunities, enhancing social support, and reducing stigma, are needed
Searches for Long Lived Neutral Particles
An intriguing possibility for TeV scale physics is the existence of neutral
long lived particles (LOLIPs) that subsequently decay into SM states. Such
particles are many cases indistinguishable from missing transverse energy (MET)
at colliders. We propose new methods to search for these particles using
neutrino telescopes. We study their detection prospects, assuming production
either at the LHC or through dark matter (DM) annihilations in the Sun and the
Earth. We find that the sensitivity for LOLIPs produced at the LHC is limited
by luminosity and detection energy thresholds. On the other hand, in the case
of DM annihilation into LOLIPs, the sensitivity of neutrino telescopes is
promising and may extend beyond the reach of upcoming direct detection
experiments. In the context of low scale hidden sectors weakly coupled to the
SM, such indirect searches allow to probe couplings as small as 10^-15.Comment: 22 pages, 6 figure
Provider Perspectives Regarding the Health Care Needs of a Key Population: HIV-infected Prisoners After Incarceration
During incarceration, many HIV-infected prisoners receive care and are adherent to medication. However, following release, many have difficulty engaging in HIV care and remaining on antiretroviral therapy (ART). Community-based service providers for HIV-infected releasees have a deep understanding of the health needs and challenges these individuals face on community re-entry. We conducted in-depth qualitative interviews with 38 health care and service professionals in 2 U.S. southern states regarding the barriers releasees faced in meeting their health needs, including HIV care and treatment post-release. Individual, community, and organization-level barriers to HIV care and treatment adherence post-release were identified and offered unique insight into the ways that these multi-level obstacles affect HIV-infected former prisoners’ abilities to engage in care and access necessary social services. Provider perspectives should be considered when designing interventions to support HIV care after release
Developmental Toxicity of Nicotine: A Transdisciplinary Synthesis and Implications for Emerging Tobacco Products
While the health risks associated with adult cigarette smoking have been well described, effects of nicotine exposure during periods of developmental vulnerability are often overlooked. Using MEDLINE and PubMed literature searches, books, reports and expert opinion, a transdisciplinary group of scientists reviewed human and animal research on the health effects of exposure to nicotine during pregnancy and adolescence. A synthesis of this research supports that nicotine contributes critically to adverse effects of gestational tobacco exposure, including reduced pulmonary function, auditory processing defects, impaired infant cardiorespiratory function, and may contribute to cognitive and behavioral deficits in later life. Nicotine exposure during adolescence is associated with deficits in working memory, attention, and auditory processing, as well as increased impulsivity and anxiety. Finally, recent animal studies suggest that nicotine has a priming effect that increases addiction liability for other drugs. The evidence that nicotine adversely affects fetal and adolescent development is sufficient to warrant public health measures to protect pregnant women, children, and adolescents from nicotine exposure
New physics searches with heavy-ion collisions at the CERN Large Hadron Collider
This document summarises proposed searches for new physics accessible in the heavy-ion mode at the CERN Large Hadron Collider (LHC), both through hadronic and ultraperipheral gamma gamma interactions, and that have a competitive or, even, unique discovery potential compared to standard proton-proton collision studies. Illustrative examples include searches for new particles-such as axion-like pseudoscalars, radions, magnetic monopoles, new long-lived particles, dark photons, and sexaquarks as dark matter candidates-as well as new interactions, such as nonlinear or non-commutative QED extensions. We argue that such interesting possibilities constitute a well-justified scientific motivation, complementing standard quark-gluon-plasma physics studies, to continue running with ions at the LHC after the Run-4, i.e. beyond 2030, including light and intermediate-mass ion species, accumulating nucleon-nucleon integrated luminosities in the accessible fb(-1) range per month.Peer reviewe
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