The solid state photomultiplier: Status of photon counting beyond the near-infrared

Rockwell International's Solid State Photomultiplier (SSPM) is an impurity-band avalanche device which can count individual photons with wavelengths between 0.4 and 28 micrometers. Its response to a photon is a pulse of between 10(exp 4) and 10(exp 5) conduction electrons, making it an important device for use in phenomenology. The characteristics of the SSPM make it a potentially important device for use in astronomical applications. Contract NAS2-12400 was initiated in June 1986 to conduct modeling and characterization studies of the SSPM to provide a basis for assessing its use in astronomical systems. Some SSPM models and results of measurements which characterize the group of SSPMs recently fabricated on this contract are discussed

Vasopressin

Antidiuretic hormone liberated the vertebrates from their aqueous environment, and permitted them to establish themselves on dry land. The combination of sensitive volume and osmoreceptors, a pituitary secretory apparatus which can vary its output from virtually zero to high levels in a short space of time, and receptor cells functioning in the countercurrent system of the renal medulla, has resulted in a water conservation system of great efficiency. The hormone rapidly alters the luminal membrane of receptor cells in the collecting tubule and collecting duct, increasing the permeability of these structures to water.1 The permeability of the collecting duct to urea and sodium is also increased.This review will be centered on the sequence of events that follows the attachment of vasopressin to its receptors in the distal nephron. This has become an area of intense activity since the discovery by Sutherland and his colleagues of the central role of cyclic AMP in the action of hormones [2]. The review will cover in brief much of the ground covered by the extensive review of Handler and OrlofT [3], emphasizing recent additions to the literature. It is regrettable that the important advances in our understanding of the synthesis and release of antidiuretic hormone cannot be included; the reader is referred to recent symposia and reviews in this area [4–6], as well as in the comparative physiology of water regulation [7] and the countercurrent system [8]

Coping and Management Techniques Used by Chronic Low Back Pain Patients Receiving Treatment From Chiropractors.

OBJECTIVES:The purpose of this study was to describe coping strategies (eg, mechanisms, including self-treatment) that a person uses to reduce pain and its impact on functioning as reported by patients with chronic low back pain who were seen by doctors of chiropractic and how these coping strategies vary by patient characteristics. METHODS:Data were collected from a national sample of US chiropractic patients recruited from chiropractic practices in 6 states from major geographical regions of the United States using a multistage stratified sampling strategy. Reports of coping behaviors used to manage pain during the past 6 months were used to create counts across 6 domains: cognitive, self-care, environmental, medical care, social activities, and work. Exploratory analyses examined counts in domains and frequencies of individual items by levels of patient characteristics. RESULTS:A total of 1677 respondents with chronic low back pain reported using an average of 9 coping behaviors in the prior 6 months. Use of more types of behaviors were reported among those with more severe back pain, who rated their health as fair or poor and who had daily occurrences of pain. Exercise was more frequent among the healthy and those with less pain. Female respondents tended to report using more coping behaviors than men, and Hispanics more than non-Hispanics. CONCLUSION:Persons with chronic back pain were proactive in their coping strategies and frequently used self-care coping strategies like those provided by chiropractors in patient education. In alignment with patients' beliefs that their condition was chronic and lifelong, many patients attempted a wide range of coping strategies to relieve their pain

Experiences With Chiropractic Care for Patients With Low Back or Neck Pain.

BackgroundMusculoskeletal disorders are the second leading cause of disability worldwide.ObjectiveExamine experiences of chiropractic patients in the United States with chronic low back or neck pain.MethodObservational study of 1853 chronic low back pain and neck pain patients (74% female) who completed an online questionnaire at the 3-month follow-up that included Consumer Assessment of Healthcare Providers and Systems (CAHPS) items assessing their experiences with care.ResultsWe found similar reports of communication for the chiropractic sample and patients in the 2016 CAHPS National Database, but 85% in the database versus 79% in the chiropractic sample gave the most positive response to the time spent with provider item. More patients in the CAHPS database rated their provider at the top of the scale (8 percentage points). More chiropractic patients reported always getting answers to questions the same day (16 percentage points) and always being seen within 15 minutes of their appointment time (29 percentage points).ConclusionsThe positive experiences of patients with chronic back and neck pain are supportive of their use of chiropractic care

Direct microwave measurement of Andreev-bound-state dynamics in a proximitized semiconducting nanowire

The modern understanding of the Josephson effect in mesosopic devices derives from the physics of Andreev bound states, fermionic modes that are localized in a superconducting weak link. Recently, Josephson junctions constructed using semiconducting nanowires have led to the realization of superconducting qubits with gate-tunable Josephson energies. We have used a microwave circuit QED architecture to detect Andreev bound states in such a gate-tunable junction based on an aluminum-proximitized InAs nanowire. We demonstrate coherent manipulation of these bound states, and track the bound-state fermion parity in real time. Individual parity-switching events due to non-equilibrium quasiparticles are observed with a characteristic timescale $T_\mathrm{parity} = 160\pm 10~\mathrm{\mu s}$. The $T_\mathrm{parity}$ of a topological nanowire junction sets a lower bound on the bandwidth required for control of Majorana bound states

Solution to the problem of the poor cyclic fatigue resistance of bulk metallic glasses

The recent development of metallic glass-matrix composites represents a particular milestone in engineering materials for structural applications owing to their remarkable combination of strength and toughness. However, metallic glasses are highly susceptible to cyclic fatigue damage, and previous attempts to solve this problem have been largely disappointing. Here, we propose and demonstrate a microstructural design strategy to overcome this limitation by matching the microstructural length scales (of the second phase) to mechanical crack-length scales. Specifically, semisolid processing is used to optimize the volume fraction, morphology, and size of second-phase dendrites to confine any initial deformation (shear banding) to the glassy regions separating dendrite arms having length scales of ≈2 μm, i.e., to less than the critical crack size for failure. Confinement of the damage to such interdendritic regions results in enhancement of fatigue lifetimes and increases the fatigue limit by an order of magnitude, making these “designed” composites as resistant to fatigue damage as high-strength steels and aluminum alloys. These design strategies can be universally applied to any other metallic glass systems

Incentive Sensitization for Exercise Reinforcement to Increase Exercise Behaviors

Individuals can be sensitized to the reinforcing effects of exercise, although it is unknown if this process increases habitual exercise behavior. Sedentary men and women (body mass index: 25–35 kg/m2, N = 52) participated in a 12-week aerobic exercise intervention. Exercise reinforcement was determined by how much work was performed for exercise relative to a sedentary alternative in a progressive ratio schedule task. Habitual physical activity was assessed via accelerometry. Post-intervention increases in exercise reinforcement predicted increases in physical activity bouts among those who expended over 2000 kcal per week in exercise and who compensated for less than 50 percent of their exercise energy expenditure

Associations of Partner Support and Acculturation With Physical Activity in Mexican American Women.

IntroductionInsufficient physical activity (PA) and obesity-related health conditions have reached epidemic proportions worldwide. Mexican American women (MAW) report low leisure time physical activity. Few studies examine activities beyond leisure time. Qualitative research suggests that partner support influence provides a cultural approach relevant to PA among MAW.MethodThis cross-sectional study used an ecological model to investigate community (the physical environment), interpersonal (partner support, attitudinal familism), and intrapersonal (age, health conditions, acculturation, employment, and body mass index) factors associated with PA among 112 MAW. Community-based participatory research recommendations guided the preparatory phase of the study and the face-to-face interviews. Frequencies and descriptive statistics were computed. Multivariable linear regression analyses were used to examine associations between study variables.ResultsModerate to high PA levels were found based on combined activities performed during leisure time, transportation, household tasks, and occupational duties. Women with greater partner support reported higher PA levels. Although acculturation levels were low among women, those with higher acculturation were found to be more physically active.ConclusionsFuture studies should examine strategies to increase partner support and address acculturation within intervention programs to enhance overall PA among MAW

The Consequences of Exercise-Induced Weight Loss on Food Reinforcement. A Randomized Controlled Trial

BACKGROUND: Obesity remains a primary threat to the health of most Americans, with over 66% considered overweight or obese with a body mass index (BMI) of 25 kg/m2 or greater. A common treatment option many believe to be effective, and therefore turn to, is exercise. However, the amount of weight loss from exercise training is often disappointingly less than expected with greater amounts of exercise not always promoting greater weight loss. Increases in energy intake have been prescribed as the primary reason for this lack of weight loss success with exercise. Research has mostly focused on alterations in hormonal mediators of appetite (e.g.: ghrelin, peptide YY, GLP-1, pancreatic polypeptide, and leptin) that may increase hunger and/or reduce satiety to promote greater energy intake with exercise training. A less understood mechanism that may be working to increase energy intake with exercise is reward-driven feeding, a strong predictor of energy intake and weight status but rarely analyzed in the context of exercise. DESIGN: Sedentary men and women (BMI: 25-35 kg/m2, N = 52) were randomized into parallel aerobic exercise training groups partaking in either two or six exercise sessions/week, or sedentary control for 12 weeks. METHODS: The reinforcing value of food was measured by an operant responding progressive ratio schedule task (the behavioral choice task) to determine how much work participants were willing to perform for access to a healthy food option relative to a less healthy food option before and after the exercise intervention. Body composition and resting energy expenditure were assessed via DXA and indirect calorimetry, respectively, at baseline and post testing. RESULTS: Changes in fat-free mass predicted the change in total amount of operant responding for food (healthy and unhealthy). There were no correlations between changes in the reinforcing value of one type of food (healthy vs unhealthy) to changes in body composition. CONCLUSION: In support of previous work, reductions in fat-free mass resulting from an aerobic exercise intervention aimed at weight loss plays an important role in energy balance regulation by increasing operant responding for food