A cryogenic continuously rotating half-wave plate mechanism for the POLARBEAR-2b cosmic microwave background receiver.

We present the design and laboratory evaluation of a cryogenic continuously rotating half-wave plate (CHWP) for the POLARBEAR-2b (PB-2b) cosmic microwave background receiver, the second installment of the Simons Array. PB-2b will observe at 5200 m elevation in the Atacama Desert of Chile in two frequency bands centered at 90 GHz and 150 GHz. In order to suppress atmospheric 1/f noise and mitigate systematic effects that arise when differencing orthogonal detectors, PB-2b modulates linear sky polarization using a CHWP rotating at 2 Hz. The CHWP has a 440 mm clear aperture diameter and is cooled to ≈50 K in the PB-2b receiver cryostat. It consists of a low-friction superconducting magnetic bearing and a low-torque synchronous electromagnetic motor, which together dissipate <2 W. During cooldown, a grip-and-release mechanism centers the rotor to <0.5 mm, and during continuous rotation, an incremental optical encoder measures the rotor angle with a noise level of 0.1 µrad/Hz. We discuss the experimental requirements for the PB-2b CHWP, the designs of its various subsystems, and the results of its evaluation in the laboratory. The presented CHWP has been deployed to Chile and is expected to see first light on PB-2b in 2020 or 2021.

Does inhaled pollen enter the sinus cavities?

BACKGROUND: While there is evidence of an increased incidence of sinusitis in patients with allergic rhinitis, it is unclear whether an allergic process occurs in the sinus tissues per se. OBJECTIVE: The purpose of this study was to determine whether inhaled pollen reaches the sinus mucosa. METHODS: Tc99m labeled ragweed pollen was inhaled by five non-atopic adults. Imaging studies of the sinuses were performed with a tomographic rotating gamma camera. To determine the sensitivity of the technique, the nose and the maxillary sinuses of cadaver heads were painted with varying amounts of Tc99m and then similarly scanned. RESULTS: Scans of the cadaver heads showed clear resolution between the nasal cavity and the maxillary sinus. It was determined that 20 microci was the smallest amount of Tc99m that could be resolved to be in the sinuses. Scans of subjects showed intense activity in the nasal cavity but none in the paranasal sinuses despite the delivery of a supraphysiologic dose of Tc99m ragweed pollen. CONCLUSION: Inhaled ragweed pollen does not appear to enter the paranasal sinuses. It is unlikely that an inhaled antigen-IgE antibody reaction occurs in the sinus mucosa.

The single-stapled ileo pouch anal anastomosis: a reasonable compromise.

Minimal anal sphincter disruption and preservation of the transitional epithelium during ileal pouch anal anastomosis (IPAA) are believed to play important roles in improving functional outcome. As a result, many surgeons have abandoned the traditional mucosectomy in favor of a double-stapled technique. The natural history of the retained colonic epithelium that occurs with this approach is uncertain. The authors have employed a technique of single circular-stapled IPAA, which accomplishes both of the described goals, while insuring that all the colonic mucus is removed during mucosectomy. We present a series of patients (n = 39) undergoing IPAA with transanal mucosectomy and a circular stapled anastomosis. The series consists of 16 males and 23 females with a mean age of 33.4 +/- 1.7 years. Twenty-nine patients had temporary ileostomies (2 not closed yet), and 10 did not. Pelvic sepsis occurred in two patients. However, three (9%) patients developed anastomotic sinus tracts that delayed ileostomy closure. With a follow-up of 24.0 +/- 3.2 months, the mean number of bowel movements are: day 6.4 +/- 0.4; night 1.1 +/- 0.2. Continence has been good or excellent in 97 per cent of patients during the day and 86 per cent at night. Therefore, this series indicates that good to excellent functional results following IPAA in the vast majority of patients can be accomplished with a transanal mucosectomy and a single stapled IPAA anastomotic technique. These results are comparable with those obtained with the double stapling technique without risk of retained rectal mucosa. Therefore, this technique provides good functional results because of minimal anal sphincter stretching, while at the same time insuring removal of all abnormal colonic epithelium.

An effective computer-based tardive dyskinesia monitoring system.

To promote early recognition and treatment of neuroleptic-induced tardive dyskinesia we used our facility's pharmacy and appointment data bases to develop an automated reminder system that significantly improved physician monitoring of patients receiving antipsychotic drug therapy. The system prompts staff to perform regular examinations for abnormal involuntary movements and to review patients' consent to therapy with antipsychotic medication. The average prevalences in the 15 months after automated reminders began, in a population of over 800 patients, increased from 53% to 85% for an annually completed abnormal involuntary movement scale in medical records and from 38 to 74% for a statement of informed consent. Now, 45 months later, prevalences of both measures approaches 100%. The integrated design of the Department of Veterans Affairs computer system allowed linking pharmacy and appointment scheduling data and facilitated the project. The reminder system effectively promoted rapid, marked, and sustained change in physicians' documentation of antipsychotic drug therapy.

The black soldier fly Hermetia illucens (Diptera: Stratiomyidae) as a potential measure of human postmortem interval: observations and case histories.

The black soldier fly, Hermetia illucens (L.), has been shown to be a ubiquitous inhabitant of both surface and buried human remains throughout the southern, central and western United States and Hawaii. Unlike most other species of forensically important Diptera, this species frequently dominates bodies in the dry/post decay stage of decomposition. Adults of the black soldier fly appear to initiate oviposition (egg laying) 20 to 30 days postmortem. Even at warm temperatures (27.8 degrees C), subsequent completion of the life cycle can require an additional 55 days. Life history data for H. illucens, when used in combination with data for other cohabiting arthropod species and viewed in the context of local environmental conditions, can provide medicolegal investigators with valuable parameters for estimating the postmortem intervals for badly decomposed remains.

Extracorporeal circulation in the fetal lamb. Effects of hypothermia and perfusion rate.

The poor prognosis of certain cardiac abnormalities detected prenatally by echocardiography has led some investigators to consider intrauterine cardiac surgery. Investigation into the efficacy of open cardiac procedures in-utero will require techniques for safe and effective fetal extracorporeal circulation and myocardial protection. We performed cardiopulmonary bypass in 8 fetal lambs to assess the feasibility of fetal cardiopulmonary bypass. Four fetuses underwent studies at 37 degrees C (Group I) and 4 at 25 degrees C (Group II). The aorta was clamped and cold crystalloid cardioplegia administered. Perfusion was carried out for 10 minutes each at high (95 +/- 18 cc/kg/min), moderate (67 +/- 10 cc/kg/min), and low (49 +/- 8 cc/kg/min) flow rates while hemodynamic and blood gas measurements were made. Total time on bypass averaged 57 min in Group I and 75 min in Group II. Four fetuses were successfully weaned from bypass following the study period. Fetal pO2 and oxygen saturation was very low at all flow rates in Group II and at low flow rates in Group I, indicating poor function of the placenta as an oxygenator at 25 degrees C and at low flow rates during normothermia. Lambs undergoing bypass at 37 degrees C had a progressive rise in pCO2 levels as flow decreased, while pCO2 was relatively normal at all flow rates at 25 degrees C. These studies serve as a starting point for the development of techniques to allow intrauterine correction of experimentally produced fetal cardiac lesions.

A comparison of radial, brachial, and aortic pressures after cardiopulmonary bypass.

Previous investigations have identified falsely low radial artery pressures after cardiopulmonary bypass (CPB). The present study investigates the relationship among radial, brachial, and aortic arterial pressures in 33 cardiac surgical patients following CPB. Two minutes after separation from CPB, clinically important (greater than or equal to 10 mmHg) underestimation of systolic aortic pressures occurred in 17 of 33 (52%) radial artery catheters, while occurring in seven of 33 (21%) brachial artery catheters. Radial artery mean pressure underestimated aortic mean pressure by greater than or equal to 5 mmHg in 21 of 33 (61%) patients two minutes after CPB, while an equivalent aortic-to-brachial artery mean arterial pressure difference occurred in nine of 33 (27%) patients. The incidence of aortic-to-radial mean arterial pressure differences greater than or equal to 5 mmHg decreased to 40% (four of ten patients) by ten minutes after CPB, although interpretation is complicated by decreased availability of aortic pressure measurements. Multivariate analysis failed to identify factors predisposed to central-to-peripheral pressure gradients. Radial and brachial arterial pressures were compared both before and after CPB in all 33 patients. Brachial artery systolic and mean pressures were higher than corresponding radial artery measurements two minutes after CPB (P less than 0.05), followed by gradual resumption of a normal brachial-to-radial pressure relationship over 60 minutes. Either vasospasm in the brachial and radial arteries or profound arteriolar vasodilation in the upper extremity might cause the observed central-to-peripheral arterial pressure differences. The progressive central-to-peripheral decrease in mean arterial pressure favors the latter mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)

Regional blood flow in canine brain during nicotine infusion: effect of autonomic blocking drugs.

Radioactive microspheres (15 mu) were used to measure regional cerebral blood flow during intravenous infusion of nicotine (36 micrograms/kg/min) in anesthetized, open chest dogs. Experiments were conducted with uncontrolled mean aortic pressure and intact autonomic receptors (Series I; n = 9), and in four groups of dogs with mean aortic pressure held constant (Series II); 1) with intact autonomic receptors (n = 6), 2) after beta adrenergic blockade (n = 8), 3) after alpha and beta adrenergic blockade (n = 6), 4) after alpha and beta adrenergic and cholinergic blockade (n = 4). In Series I, nicotine raised mean aortic pressure (+ 72%) and increased flow in cerebral cortex (+ 67%), cerebellum (+ 38%), pons (+ 46%), medulla (+ 39%), and spinal cord (+ 48%). In all regions, but cortex, increases in vascular resistance limited nicotine-induced increases in flow. In Series II, nicotine changed flow only in cortex. Without blockade, nicotine increased cortical flow (+ 38%); but beta blockade abolished this increase in flow. After alpha and beta blockade nicotine again raised cortical flow (+ 29%), and additional cholinergic blockade had no effect on this response. It is concluded that nicotine causes predominant beta receptor mediated vasodilation in cerebral cortex, although it also activates alpha (vasoconstrictor) receptors and a non-adrenergic, non-cholinergic vasodilator mechanism in this region of brain.

Diet of racing sled dogs affects erythrocyte depression by stress.

Fourteen racing huskies were matched into pairs then assigned to two diets, a commercial stress diet and an experimental diet. Proportions of protein: fat:carbohydrate on an available energy basis were 23:57:20 in a commercial stress diet and 28:69:3 in an experimental diet. The team participated in the 1979 Iditarod Trail race and was overtaken by an episode of diarrhea. Clinical signs were suggestive of parvovirus infection; high serum titers of parvo antibodies were found after the race. Blood examination showed normal levels of metabolites, electrolytes and enzymes after the race. Erythrocyte counts were depressed significantly during the race, by 15% in dogs fed an experimental diet and by 27% in those fed a commercial stress diet. Erythrocyte parameters have also become depressed during the racing season in middle distance sled dogs fed 28% protein (energy basis) but not 32 or 39%. Depressed red blood cell production has been demonstrated previously in dogs subjected to stress induced experimentally in several ways, and its restoration has been affected by dietary protein. Erythrocyte parameters may be useful indicies of the degree of stress in a dog as well as the adequacy of its protein intake during stress.

Rocky Mountain spotted fever (tick-borne typhus) in South Carolina: an educational program and tick/rickettsial survey in 1973 and 1974.

Because the incidence of spotted fever is increasing in South Carolina, campaigns were carried out in 1973 and 1974 to provide the public and medical practitioners, through pamphlets and news media, with information about spotted fever and the ticks which transmit the causative agent, Rickettsia rickettsii. People were also invited to save and submit live ticks removed from vegetation, animals and humans, for examination by the hemolymph test. A total of 1,186 ticks consisting of 987 Dermacentor variabilis, 103 Rhipicephalus sanguineus, and 96 Amblyomma americanum were examined. Rickettsiae identified by direct immunofluorescence as members of the spotted fever group were detected in 49 (4.9%) of the D. variabilis, and 16 (16.6%) of the A. americanum ticks. Two hundred and twenty (199 D. variabilis, 17 A. americanum, and 4 R. sanguineus) were recorded as having been attached to 199 persons. Nine of these ticks (8 D. variabilis, and 1 A. americanum) were hemolymph test-positive for spotted fever-group rickettsiae. Infected ticks originated from each of the three major South Carolina biogeographic regions, namely Piedmont, Sandhill, and Coastal Plain. Since education is the first and most important step in preventing spotted fever, educational programs and tick examination services similar to those decribed, are suggested for other states with high spotted fever incidence.