Dual cathode system for electron beam instruments

An electron beam source having a single electron optical axis is provided with two coplanar cathodes equally spaced on opposite sides from the electron optical axis. A switch permits selecting either cathode, and a deflection system comprised of electromagnets, each with separate pole pieces equally spaced from the plane of the cathodes and electron optical axis, first deflects the electron beam from a selected cathode toward the electron optical axis, and then in an opposite direction into convergence with the electron optical axis. The result is that the electron beam from one selected cathode undergoes a sigmoid deflection in two opposite directions, like the letter S, with the sigmoid deflection of each being a mirror image of the other

Bluetongue virus infection creates light averse Culicoides vectors and serious errors in transmission risk estimates.

BackgroundPathogen manipulation of host behavior can greatly impact vector-borne disease transmission, but almost no attention has been paid to how it affects disease surveillance. Bluetongue virus (BTV), transmitted by Culicoides biting midges, is a serious disease of ruminant livestock that can cause high morbidity and mortality and significant economic losses. Worldwide, the majority of surveillance for Culicoides to assess BTV transmission risk is done using UV-light traps. Here we show that field infection rates of BTV are significantly lower in midge vectors collected using traps baited with UV light versus a host cue (CO2).MethodsWe collected Culicoides sonorensis midges in suction traps baited with CO2, UV-light, or CO2 + UV on three dairies in southern California to assess differences in the resulting estimated infection rates from these collections. Pools of midges were tested for BTV by qRT-PCR, and maximum likelihood estimates of infection rate were calculated by trap. Infection rate estimates were also calculated by trapping site within a dairy. Colonized C. sonorensis were orally infected with BTV, and infection of the structures of the compound eye was examined using structured illumination microscopy.ResultsUV traps failed entirely to detect virus both early and late in the transmission season, and underestimated virus prevalence by as much as 8.5-fold. CO2 + UV traps also had significantly lower infection rates than CO2-only traps, suggesting that light may repel infected vectors. We found very high virus levels in the eyes of infected midges, possibly causing altered vision or light perception. Collecting location also greatly impacts our perception of virus activity.ConclusionsBecause the majority of global vector surveillance for bluetongue uses only light-trapping, transmission risk estimates based on these collections are likely severely understated. Where national surveillance programs exist, alternatives to light-trapping should be considered. More broadly, disseminated infections of many arboviruses include infections in vectors' eyes and nervous tissues, and this may be causing unanticipated behavioral effects. Field demonstrations of pathogen-induced changes in vector behavior are quite rare, but should be studied in more systems to accurately predict vector-borne disease transmission

Management of Morel-Lavallee lesion of the knee: Twenty-seven cases in the National Football League

BACKGROUND: The Morel-Lavallee lesion is a closed degloving injury most commonly described in the region of the hip joint after blunt trauma. It also occurs in the knee as a result of shearing trauma during football and is a distinct lesion from prepatellar bursitis and quadriceps contusion. PURPOSE: To review the authors\u27 experience with Morel-Lavallee lesion of the knee in the elite contact athlete to construct a diagnostic and treatment algorithm. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Twenty-seven knees in 24 players were identified from 1 National Football League team\u27s annual injury database as having sustained a Morel-Lavallee lesion between 1993 and 2006. Their charts were retrospectively reviewed. RESULTS: The most common mechanism of injury was a shearing blow on the playing surface (81%). The most common motion deficit was active flexion (41%). The mean time for resolution of the fluid collection and achievement of full active flexion was 16.3 days. The mean number of practices missed was 1.5. The mean number of games missed was 0.1. Fourteen knees (52%) were treated successfully with compression wrap, cryotherapy, and motion exercises. Thirteen knees (48%) were treated with at least 1 aspiration, and 6 knees (22%) were treated with multiple aspirations for recurrent serosanguineous fluid collections. In 3 cases (11%), the Morel-Lavallee lesion was successfully treated with doxycycline sclerodesis after 3 aspirations failed to resolve the recurrent fluid collections; return to play was immediate thereafter in each case. CONCLUSION: In football, Morel-Lavallee lesion of the knee usually occurs from a shearing blow from the playing field. Diagnosis is confirmed when examination reveals a large suprapatellar area of palpable fluctuance. Elite athletes are typically able to return to practice and game play long before complete resolution of the lesion. Recurrent fluid collections can occur, necessitating aspiration in approximately half the cases for successful treatment. Recalcitrant fluid collections can be safely and expeditiously treated with doxycycline sclerodesis

Miniaturization in x ray and gamma ray spectroscopy

The paper presents advances in two new sensor technologies and a miniaturized associated electronics technology which, when combined, can allow for very significant miniaturization and for the reduction of weight and power consumption in x-ray and gamma-ray spectroscopy systems: (1) Mercuric iodide (HgI2) x-ray technology, which allows for the first time the construction of truly portable, high-energy resolution, non-cryogenic x-ray fluorescence (XRF) elemental analyzer systems, with parameters approaching those of laboratory quality cryogenic instruments; (2) the silicon avalanche photodiode (APD), which is a solid-state light sensitive device with internal amplification, capable of uniquely replacing the vacuum photomultiplier tube in scintillation gamma-ray spectrometer applications, and offering substantial improvements in size, ruggedness, low power operation and energy resolution; and (3) miniaturized (hybridized) low noise, low power amplification and processing electronics, which take full advantage of the favorable properties of these new sensors and allow for the design and fabrication of advanced, highly miniaturized x-ray and gamma-ray spectroscopy systems. The paper also presents experimental results and examples of spectrometric systems currently under construction. The directions for future developments are discussed

On Signatures of Atmospheric Features in Thermal Phase Curves of Hot Jupiters

Turbulence is ubiquitous in Solar System planetary atmospheres. In hot Jupiter atmospheres, the combination of moderately slow rotation and thick pressure scale height may result in dynamical weather structures with unusually large, planetary-size scales. Using equivalent-barotropic, turbulent circulation models, we illustrate how such structures can generate a variety of features in the thermal phase curves of hot Jupiters, including phase shifts and deviations from periodicity. Such features may have been spotted in the recent infrared phase curve of HD 189733b. Despite inherent difficulties with the interpretation of disk-integrated quantities, phase curves promise to offer unique constraints on the nature of the circulation regime present on hot Jupiters.Comment: 22 pages, 6 figures, 1 table, accepted for publication in Ap

Macrocerebellum: Neuroimaging and Clinical Features of a Newly Recognized Condition

Other than hamartomatous enlargement of the cerebellum as in Lhermitte-Duclos syndrome, diffuse enlargement of the cerebellum is not clearly described. We report four patients (ages 9 months to 2 years) with diffusely enlarged cerebelli as identified by measurement of the cerebellum and comparison to age appropriate normal values. The cerebellar measurements were determined in absolute numbers and expressed as ratios of cerebellum to whole brain and supratentorial brain. The clinical features of these four children (3 boys, 1 girl) consistently include global developmental delay, tone abnormalities, preserved reflexes, delayed or abnormal maturation of the visual system (oculomotor apraxia), and deficient or delayed myelination of cerebral white matter. The etiology of the macrocerebellum is unknown but we propose that the cerebellum is responding to the elaboration of growth factors intended to augment the slow development of cerebral structures. Regardless of the etiology, the finding of a macrocerebellum appears to allow the clinician to predict the clinical features of the patient and probably represents a marker for disturbed cerebral development. (J Child Neurol 1997;12:365-368).Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Safety Recommendations for Evaluation and Surgery of the Head and Neck During the COVID-19 Pandemic

Importance The rapidly expanding novel coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2, has challenged the medical community to an unprecedented degree. Physicians and health care workers are at added risk of exposure and infection during the course of patient care. Because of the rapid spread of this disease through respiratory droplets, health care workers who come in close contact with the upper aerodigestive tract during diagnostic and therapeutic procedures, such as otolaryngologists–head and neck surgeons, are particularly at risk. A set of safety recommendations was created based on a review of the literature and communications with physicians with firsthand knowledge of safety procedures during the COVID-19 pandemic. Observations A high number of health care workers were infected during the first phase of the pandemic in the city of Wuhan, China. Subsequently, by adopting strict safety precautions, other regions were able to achieve high levels of safety for health care workers without jeopardizing the care of patients. The most common procedures related to the examination and treatment of upper aerodigestive tract diseases were reviewed. Each category was reviewed based on the potential risk imposed to health care workers. Specific recommendations were made based on the literature, when available, or consensus best practices. Specific safety recommendations were made for performing tracheostomy in patients with COVID-19. Conclusions and Relevance Preserving a highly skilled health care workforce is a top priority for any community and health care system. Based on the experience of health care systems in Asia and Europe, by following strict safety guidelines, the risk of exposure and infection of health care workers could be greatly reduced while providing high levels of care. The provided recommendations, which may evolve over time, could be used as broad guidance for all health care workers who are involved in the care of patients with COVID-19

Ultra-High-Resolution Optical Coherence Tomographic Findings in Commotio Retinae

Commotio retinae is a self-limited opacification of the retina secondary to direct blunt ocular trauma. Histologic studies of monkeys and humans relate this clinical observation to damaged photoreceptor outer segments and receptor cell bodies.[superscript 1 - 3] Reports using time-domain optical coherence tomography (OCT) and spectral-domain OCT support the involvement of the photoreceptor layer, but these techniques lack the resolution necessary to confirm results of histologic analysis.[superscript 4 - 6] Prototype high-speed ultra–high-resolution OCT (hs-UHR-OCT) images demonstrate these anatomical changes in a patient with acute commotio retinae.National Institutes of Health (U.S.) (Contract Number RO1-EY11289-23)National Institutes of Health (U.S.) (Contract Number R01-EY13178-07)United States. Air Force Office of Scientific Research (Grant Number FA9550-07-1-0101)United States. Air Force Office of Scientific Research (Grant Number FA9550-07-1-0014