Energetic ion loss diagnostic for the Wendelstein 7-AS stellarator

A diagnostic to measure the loss of energetic ions from the Wendelstein 7-AS (W7-AS) stellarator has been built. It is capable of measuring losses of both neutral beam ions and energetic ions arising from ion cyclotron resonant heating. The probe can measure losses of both clockwise and counterclockwise-going energetic ions simultaneously, and accepts a wide range of pitch angles in both directions. Initial measurements by the diagnostic are reported

Evidence for Community Face Masking to Limit the Spread of SARS-CoV-2: A Critical Review

The use of facemasks in community settings has become an accepted public policy response to decrease disease transmission during the COVID-19 pandemic. Yet evidence of facemask efficacy is based primarily on observational studies that are subject to confounding and on mechanistic studies that rely on surrogate endpoints (such as droplet dispersion) as proxies for disease transmission. The available clinical evidence of facemask efficacy is of low quality and the best available clinical evidence has mostly failed to show efficacy, with fourteen of sixteen identified randomized controlled trials comparing face masks to no mask controls failing to find statistically significant benefit in the intent-to-treat populations. Of sixteen quantitative meta- analyses, eight were equivocal or critical as to whether evidence supports a public recommendation of masks, and the remaining eight supported a public mask intervention on limited evidence primarily on the basis of the precautionary principle. Although weak evidence should not preclude precautionary actions in the face of unprecedented events such as the COVID-19 pandemic, ethical principles require that the strength of the evidence and best estimates of amount of benefit be truthfully communicated to the public

Solid State Neutral Particle Analyzer Array on NSTX

A Solid State Neutral Particle Analyzer (SSNPA) array has been installed on the National Spherical Torus Experiment (NSTX). The array consists of four chords viewing through a common vacuum flange. The tangency radii of the viewing chords are 60, 90, 100, and 120 cm. They view across the three co-injection neutral beam lines (deuterium, 80 keV (typ.) with tangency radii 48.7, 59.2, and 69.4 cm) on NSTX and detect co-going energetic ions. A silicon photodiode used was calibrated by using a mono-energetic deuteron beam source. Deuterons with energy above 40 keV can be detected with the present setup. The degradation of the performance was also investigated. Lead shots and epoxy are used for neutron shielding to reduce handling any hazardous heavy metal. This method also enables us to make an arbitrary shape to be fit into the complex flight tube

Correlation between excitation of Alfven modes and degradation of ICRF heating efficiency in TFTR

Alfven modes are excited by energetic ions in TFTR during intense minority ICRF heating. There is a clear threshold in rf power above which the modes are destabilized. The net effect of these modes is the increase of the fast ion losses, with an associated saturation of the ion tail energy and of the efficiency of the heating. Typically, several modes are excited with progressive n-numbers, with frequencies in the neighborhood of 200 kHz. Results suggest that Energetic Particle Modes (EPM), mostly unseen by the Mirnov coils, are generated near the center and are responsible for the ion losses. Stronger global TAE modes, which are destabilized by the stream of displaced fast ions, appear responsible only for minor losses

Limitations of Counseling and Testing in CDC\u27s HIV Prevention Efforts

To the Editor: We were delighted to see that our colleagues at the Centers for Disease Control and Prevention (CDC) had read our article (Darrow et al., 1998a) and responded (Wolitski and Doll, 1999). Their criticisms of our cross-sectional study of 51 HIV-infected men who have sex with men (MSM) and live in South Beach are welcomed and appreciated. In this brief reply, we continue the dialogue by addressing their concerns and recommending an appropriate course of action

Diagnosis and Management of Infantile Hemangioma

Infantile hemangiomas (IHs) are the most common tumors of childhood. Unlike other tumors, they have the unique ability to involute after proliferation, often leading primary care providers to assume they will resolve without intervention or consequence. Unfortunately, a subset of IHs rapidly develop complications, resulting in pain, functional impairment, or permanent disfigurement. As a result, the primary clinician has the task of determining which lesions require early consultation with a specialist. Although several recent reviews have been published, this clinical report is the first based on input from individuals representing the many specialties involved in the treatment of IH. Its purpose is to update the pediatric community regarding recent discoveries in IH pathogenesis, treatment, and clinical associations and to provide a basis for clinical decision-making in the management of IH