The Simons Observatory: Cryogenic half wave plate rotation mechanism for the small aperture telescopes

We present the requirements, design, and evaluation of the cryogenic continuously rotating half-wave plate (CHWP) for the Simons Observatory (SO). SO is a cosmic microwave background polarization experiment at Parque Astronómico de Atacama in northern Chile that covers a wide range of angular scales using both small (⌀0.42 m) and large (⌀6 m) aperture telescopes. In particular, the small aperture telescopes (SATs) focus on large angular scales for primordial B-mode polarization. To this end, the SATs employ a CHWP to modulate the polarization of the incident light at 8 Hz, suppressing atmospheric 1/f noise and mitigating systematic uncertainties that would otherwise arise due to the differential response of detectors sensitive to orthogonal polarizations. The CHWP consists of a 505 mm diameter achromatic sapphire HWP and a cryogenic rotation mechanism, both of which are cooled down to ∼50 K to reduce detector thermal loading. Under normal operation, the HWP is suspended by a superconducting magnetic bearing and rotates with a constant 2 Hz frequency, controlled by an electromagnetic synchronous motor. We find that the number of superconductors and the number of magnets that make up the superconducting magnetic bearing are important design parameters, especially for the rotation mechanism's vibration performance. The rotation angle is detected through an angular encoder with a noise level of 0.07 μrad s. During a cooldown process, the rotor is held in place by a grip-and-release mechanism that serves as both an alignment device and a thermal path. In this paper, we provide an overview of the SO SAT CHWP: its requirements, hardware design, and laboratory performance.

A trial comparing emergency front of neck airway performance in a novel obese-synthetic neck, meat-modified obese neck and conventional slim manikin

Conventional emergency front of neck airway training manikins mimic slim patients and are associated with unrealistic procedural ease. We have described previously a pork belly-modified manikin that more realistically simulated an obese patient's neck. In this study, we compared a novel obese-synthetic manikin (obese-synthetic manikin) with a pork belly-modified manikin (obese-meat manikin) and a conventional slim manikin (slim manikin). Thirty-three experienced anaesthetists undertook simulated emergency front of neck airway procedures on each manikin (total 99 procedures). Time to ventilation was longer on both obese manikins compared with the slim manikin (median (IQR [range]) time to intubation 159 (126-243 [73-647]) s in the obese-synthetic, 105 (72-138 [43-279]) s in the obese-meat and 58 (47-74 [30-370]) s in the slim manikin; p < 0.001 between each manikin). Cricothyroidotomy success rate was similar in the both obese manikins but lower when compared with the slim manikin (15/33 obese-synthetic vs. 14/33 obese-meat vs. 27/33 slim manikin). Participant feedback indicated performance difficulty was similar between both obese manikins, which were both more difficult than the slim manikin. The tissues of the obese-meat manikin were judged more realistic than those of either other manikin. Overall, the obese-synthetic manikin performed broadly similarly to the obese-meat manikin and was technically more difficult than the conventional slim manikin. The novel obese-synthetic manikin maybe useful for training and research in front of neck airway procedures.

PI 3-kinase and MAP kinase regulate bradykinin induced prostaglandin E2release in human pulmonary artery by modulating COX-2 activity

Here we studied the role of phosphoinositide 3-kinase (PI 3-kinase) and mitogen activated protein (MAP) kinase in regulating bradykinin (BK) induced prostaglandin E(2) (PGE(2)) production in human pulmonary artery smooth muscle cells (HPASMC). BK increased PGE(2) in a three step process involving phospholipase A(2) (PLA(2)), cyclooxygenase (COX) and PGE synthase (PGES). BK stimulated PGE(2) release in cultured HPASMC was inhibited by the PI 3-kinase inhibitor LY294002 and the p38 MAP kinase inhibitor SB202190. The inhibitory mechanism used by LY294002 did not involve cytosolic PLA(2) activation or COX-1, COX-2 and PGES protein expression but rather a novel effect on COX enzymatic activity. SB202190 also inhibited COX activity.

Effect of bradykinin, TGF-beta1, IL-1beta, and hypoxia on COX-2 expression in pulmonary artery smooth muscle cells

Prostanoids are major regulators of smooth muscle function that are generated by cyclooxygenase (COX). Here we hypothesized that cytokines and mediators that regulate the pulmonary circulation would alter COX expression and prostanoid generation in pulmonary artery smooth muscle cells. Bradykinin, transforming growth factor-beta1 (TGF-beta1), and interleukin-1beta (IL-1beta) increased inducible COX-2 expression and prostaglandin E(2) (PGE(2)) release. Transfection studies using a COX-2 promoter construct demonstrated that all three agents acted transcriptionally. Constitutive COX-1 protein expression was unchanged. The COX inhibitor indomethacin, the COX-2 inhibitor NS-398, the protein synthesis inhibitor cycloheximide, and the glucocorticoid dexamethasone abrogated the increased PGE(2) levels. Dexamethasone and cycloheximide prevented COX-2 induction. Hypoxia (3% O(2)-5% CO(2)-92% N(2)) for 24 h selectively augmented TGF-beta1-stimulated PGE(2) production and COX-2 induction but had no effect alone. Prolonged hypoxic culture alone for 48 and 72 h enhanced COX-2 induction and increased PGE(2). These studies show that a number of stimuli are capable of inducing COX-2 in pulmonary artery smooth muscle cells. The interaction between hypoxia and TGF-beta1 may be particularly relevant to pulmonary hypertension.

Human airway smooth muscle cells secrete vascular endothelial growth factor: up-regulation by bradykinin via a protein kinase C and prostanoid-dependent mechanism

Bronchial vascular remodeling is an important feature of the pathology of chronic asthma, but the responsible mechanisms and main sources of angiogenic factors are unclear. Here we report that human airway smooth muscle cells express vascular endothelial growth factor (VEGF)121, 165, 189, 206 splice variants and secrete VEGF protein constitutively. VEGF protein secretion was increased by the proinflammatory asthma mediator bradykinin through post-transcriptional mechanisms. Bradykinin-induced VEGF secretion was dependent on the B2 bradykinin receptor, activation of protein kinase C, and generation of endogenous prostanoids. This is the first report that bradykinin can increase VEGF secretion in any biological system and the first to show that airway smooth muscle cells produce VEGF. Our results suggest a novel role for human airway smooth muscle in contributing to bronchial mucosal angiogenesis in chronic asthma by secretion of VEGF and suggest a wider role for mesenchymal cell products in mediating angiogenesis in inflammatory and allergic diseases.

Sentinel lymph node biopsy for melanoma: experience with 234 consecutive procedures

Sentinel lymph node biopsy is increasingly used to identify occult metastases in regional lymph nodes of patients with melanoma. Selection of patients for sentinel lymph node biopsy and subsequent lymphadenectomy is an area of debate. The purpose of this study was to describe a large clinical series of these biopsies for cutaneous melanoma and to identify patients most likely to gain useful clinical information from sentinel lymph node biopsy. The Indiana University Melanoma Program computerized database was queried to identify all patients who underwent this procedure for clinically localized cutaneous melanoma. It was performed using preoperative technetium Tc 99m lymphoscintigraphy and isosulfan blue dye. Pertinent demographic, surgical, and histopathologic data were recorded. Univariate and multivariate logistic regression and classification table analyses were performed to identify clinical variables associated with sentinel node and nonsentinel node positivity. In total, 234 biopsy procedures were performed to stage 291 nonpalpable regional lymph node basins. Mean Breslow's thickness was 2.30 mm (2.08 mm for negative sentinel lymph node biopsy, 3.18 mm for positive). The mean number of sentinel nodes removed was 2.17 nodes per basin (range, 1 to 8). Forty-seven of 234 melanomas (20.1 percent) and 50 of 291 basins (17.2 percent) had a positive biopsy. Positivity correlated with AJCC tumor stage: T1, 3.6 percent; T2, 8.1 percent; T3, 27.4 percent; T4, 44 percent. By univariate logistic regression, Breslow's thickness (p = 0.003, continuous variable), ulceration (p = 0.003), mitotic index > or = 6 mitoses per high power field (p = 0.008), and Clark's level (p = 0.04) were significantly associated with sentinel lymph node biopsy result. By multivariate analysis, only Breslow's thickness (p = 0.02), tumor ulceration (p = 0.02), and mitotic index (p = 0.02) were significant predictors of biopsy positivity. Classification table analysis showed the Breslow cutpoint of 1.2 mm to be the most efficient cutpoint for sentinel lymph node biopsy result (p = 0.0004). Completion lymphadenectomy was performed in 46 sentinel node-positive patients; 12 (26.1 percent) had at least one additional positive nonsentinel node. Nonsentinel node positivity was marginally associated with the presence of multiple positive sentinel nodes (p = 0.07). At mean follow-up of 13.8 months, four of 241 sentinel node-negative basins demonstrated same-basin recurrence (1.7 percent). Sentinel lymph node biopsy is highly reliable in experienced hands but is a low-yield procedure in most thin melanomas. Patients with melanomas thicker than 1.2 mm or with ulcerated or high mitotic index lesions are most likely to have occult lymph node metastases by sentinel lymph node biopsy. Completion therapeutic lymphadenectomy is recommended after positive biopsy because it is difficult to predict the presence of positive nonsentinel nodes.

Does Dingo Predation or Buffalo Competition Regulate Feral Pig Populations in the Australian Wet-Dry Tropics? An Experimental Study

Dingo (Canis farniliaris dingo) predation on feral pigs (Sus scrofa) in response to experimental changes in prey populations was measured over seven years in the seasonally wet-dry tropics of northern Australia. Following the removal of feral swamp buffalo (Bubalus bubalis) from half of the 614-km*2 study area, the number of pigs doubled and there was a 3-fold increase of pig in dingo diet. The relationship between the functional response of the dingo and pig abundance was negative and significant for both the treatment and control areas. This indicated that dingoes were not regulating the pig population. Instead, dingo predation probably acted in concert with interference competition by buffalo which decreased access to critical subterranean food for pigs during the dry season and thus limited population growth in pigs.

An experimental test of the muscle tension hypothesis of tension-type headache

The present study employed an experimental design to provide a direct test of the classic etiological account of tension-type headaches, that these stem from elevated levels of muscle tension. Twenty-eight female subjects with relatively frequent headaches were divided into 4 groups, according to a 2 x 2 design. The independent variables were (1) Target response (to maintain elevated levels of either frontalis EMG or digital temperature for 40 min), and (2) Expectation (either specifically of a headache or of some unspecified discomfort). Dependent variables included headache as well as a number of other possible symptoms. Results showed that subjects were successful in complying with their assigned tasks. However, there were no main effects of Target response or Expectation and no interactions of these factors with respect to headache or any other symptom. These data provide strong evidence against the classic etiological account of muscle-contraction headaches.

The acute geriatric psychiatry service: a suggested model

In general hospitals, especially on acute medical-surgical, and general psychiatric units, geriatric patients are often exposed to attitudes of resentment or rejection. Individuals with treatable mental illnesses may be relatively neglected or dismissed as "senile," and their special needs not attended to. This tends to occur when the particular psychological issues of elderly patients are not shared by most of the other patients, and also when staff members are prejudiced about old people, either because of fear about their own aging or because of unresolved difficulties with parents or grandparents. The authors believe that age-specific geriatric units are the most effective treatment format for the elderly in need of psychiatric care. One example of such a unit opened in 1980, the Geriatric Psychiatry Unit currently in operation at the Johnston R. Bowman Health Center for the Elderly, a part of Rush-Presbyterian-St. Luke's Medical Center in Chicago, is described.

Recurrent hemoperitoneum in women receiving continuous ambulatory peritoneal dialysis

Of 27 women in the reproductive age group receiving continuous ambulatory peritoneal dialysis for more than 3 months, 4 of 7 who menstruated developed recurrent hemoperitoneum. Tubal ligation had been done in 3 of these 4 women. There were 37 episodes of hemoperitoneum; 22 occurred at midcycle and 15 with menstruation. One patient required repeated blood transfusion, but after oral anovulant therapy no further bleeding occurred and no transfusion was required. Two patients needed laparotomy: one for heavy intraperitoneal bleeding originating from a luteal cyst, and the other for severe lower abdominal pain from follicular and luteal cysts. Ultrasound examinations suggested the presence of small ovarian cysts in the two remaining patients. Recurrent midcycle hemoperitoneum in women on continuous ambulatory peritoneal dialysis may be triggered by ovulation and associated ovarian cyst formation. Suppression of ovulation should be considered.

Hallucinogenic N-methylated indolealkylamines in the cerebrospinal fluid of psychiatric and control populations

The incidence and quantities of dimethyltryptamine and O-methylbufotenine were studied in the cerebrospinal fluid of patients suffering acute schizophrenic illnesses and in surgical and neurological control groups. Some schizophrenic patients have higher levels of both amines than do controls, though the differences in distribution did not reach statistical significance in the sample studied. The gas-chromatographic technique used is sensitive at the low picogram level.

Technique of fluphenazine decanoate therapy in acute schizophrenic illnesses

F.D. can be safely used as the phenothiazine of first choice in the management of acute schizophrenic illness, either alone or in combination with other neuroleptics if necessary for additional sedation. Usually 2 - 5 ccs im are needed to effect remission. Striopallidal symptoms are the major problem but these are usually manageable. The advantages of this regime are discussed.

Interaction of psychoactive drugs with the Mg+2 requiring ATPase associated with isolated synaptic vesicles

A large series of CNS active drugs have been tested for their possible effect on the Mg+2 dependent ATPase associated with isolated synaptic vesicles. Antipsychotic agents and cocaine showed inhibition, of a non-competitive type. The implications of this finding for a synaptic theory of psychosis are discussed.