Pneumotachograph for flow and volume measurement in normal and dense atmospheres

Measurement of ventilatory flow during pulmonary function maneuvers and in severe exercise by the pneumotachograph flow transducer in dense atmospheres is handicapped by the inverse relationship between the linear range of such transducers and gas density. This limitation in the usefulness of the pneumotachograph can be overcome by mounting such flow transducers in parallel and taking into account the reduction in peak ventilatory flow transducers in parallel and taking into account the reduction in peak ventilatory flow which occurs with increasing density. The design of such assemblies, their static performance characteristics, and a drift subtractor, constructed to stabilize the output of the pneumotachograph pressure transducer, are described.     

A reevaluation of the relation between estrogen and emotionality in female rats.

It has been hypothesized that the emotionality of the female rat is reduced at estrus. In confirmation of previous research, the present 5 experiments with 112 Ss show that administration of estradiol benzoate (20 mug/kg) to female rats of the Maudsley Reactive (MR) strain increased open-field activity and decreased open-field defecation. In addition, ovariectomy increased open-field defecation in MR females. Supporting the generality of these findings, hormone administration reduced open-field defecation and increased open-field activity in intact females of a genetically heterogeneous background. Additional studies suggest that the decrease in open-field defecation at estrus is dependent on estrogenic suppression of food intake. Hormone replacement decreased food intake in the period preceding the open-field test, and colonic contents were also lower in rats treated with estradiol benzoate plus progesterone immediately after the completion of the open-field test. These changes were seen in both MR and genetically heterogeneous females. It is concluded that the decrease in open-field defecation at estrus may be mediated by a reduction in food intake and a consequent decrease in colonic contents and that the validity of the defecation response as a measure of emotionality may be seriously questioned under these circumstances. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Media Exposure and Attention as Mediating Variables Influencing Social Risk Judgments

This study examined the hypothesis that media exposure and attention partially mediate the effects of variables such as demographics and personal experience on risk judgments. Risk judgments, including perceived severity, prevalence, controllability, familiarity, and concern about alcohol-related injuries, comprised the outcome measures. Alcohol-related injuries included assaults, motor vehicle crashes, and other injury incidents such as falls, fire, and drowning. Results supported the hypotheses of partial mediation with respect to most risk judgment factors. In particular, effects of education, gender, sensation seeking, and prior firsthand or secondhand experience with alcohol-related mishaps on judgments of concern and/or severity were partially mediated by media variables. The authors concluded that media effects on risk judgments can be usefully understood as part of a larger social process in which media are selectively attended to due to exogenous influences; part of the effect of these exogenous influences on these social risk judgments was via these media influences. Media use variables also retain a degree of influence after controlling for these exogenous factors.     

Effects of pyridostigmine bromide on in-flight aircrew performance

The effects of a chemical defense pretreatment drug, pyridostigmine bromide (PB), on in-flight aircrew performance were assessed using the Total In-Flight Simulator (TIFS) aircraft. TIFS was used to supply appropriate control dynamics, handling characteristics, and cockpit instrumentation for a tactical transport airdrop simulation. Twenty-one C-130 pilots flew two familiarization and four data flights. During two data flights PB was given to both members of the aircrew using the dosage regimen of 30 mg/8 h prescribed by the U.S. Air Force surgeon general. The drug was administered using a double-blind technique. The results indicated that (1) aircrews successfully completed their assigned mission, (2) airdrop inaccuracies and navigation errors in time and distance were not specifically related to PB, (3) performance and crew coordination were not affected by PB, (4) PB and pilot/copilot not discriminate beyond chance between PB and placebo conditions.     

A linear algorithm for the number of degree constrained subforests of a tree

Recent work of Farrell is concerned with determining the total number of ways in which one can cover the vertices of a tree T with vertex disjoint paths. Such path covers are spanning subforests in which each vertex is restricted to have degree at most two. If b: V(T)→N is a positive integer-valued function, then finding a b-matching is equivalent to finding a spanning subgraph in which the degree of each vertex v is at most b(v). A linear-time algorithm for determining the number of b-matching in a tree is presented.     

Hierarchical clustering of mathematical journals based upon citation matrices

Journal-to-journal citation matrices can be examined with a two-stage double-standardization and hierarchical clustering procedure that has been widely applied to other transaction flow tables. An illustration is given, using 1967–1975 citations between 22 mathematical journals. Groups oriented to analysis and to algebra are discerned. Certain journals, such as theProceedings of the American Mathematical Society, are shown to have broad, nonspecialized tjes with the other periodicals.     

A Comparison of Continuous Counter-Current Ion Exchange Equipment for Regeneration of Resins

Three distinct types of continuous counter-current equipment for regeneration of ion exchange resin have been investigated. A pulsed, multi-stage column, a horizontal multi-stage stirred tank apparatus (the Morris contactor) and a periodically moving packed bed of resin were used. The resin residence time characteristics and axial mixing patterns were assessed. The moving packed bed system is most satisfactory and it has been shown that it can be superior to fixed bed apparatus.     

Preflight versus en route success and complications of rapid sequence intubation in an air medical service

Methacholine chloride bronchoprovocation challenges are performed for the diagnosis and investigation of hyperreactive airways. Over the last 20 yrs various formulations and pH values for the preparation of solutions of methacholine have been described. To determine the stability of methacholine chloride solutions prepared in a variety of buffers with differing pH values and under varying storage temperatures, we measured methacholine concentrations at intervals from 1 to 5 weeks. It was found that methacholine chloride solutions rapidly decompose if the pH is greater than 6 and that decomposition is more rapid as the pH is raised; solutions at pH 9, i.e. bicarbonate buffer, and stored at 27 degrees C have degradation up to 36% after only one week. Solutions of the same pH but prepared in different buffers can have both varied rates of deterioration and different absolute amounts of methacholine hydrolysed, e.g. solutions prepared in pH 9 borate buffer and stored at 27 degrees C have up to 60% degradation after 1 week. Solutions prepared in saline are stable probably because methacholine solutions are weakly acidic. The results emphasise the importance of preparing methacholine chloride in the proper buffers for use in the accurate assessment of airway responsiveness.     

Interpersonal stress and pain behaviors in patients with chronic pain.

Evaluated the role of interpersonal stress in eliciting pain behavior. 34 male patients with chronic back pain and their wives participated in a randomized between-groups study examining the effects of 2 interactional conditions (i.e., maritally focused stress interview and neutral talking control task) on subsequent persistence in a physically demanding task and with self-reports of pain. Results show that a greater proportion of patients in the stress interview group terminated the physical activity task prematurely, compared with controls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)