Tritium Beta Spectrum Measurement and Neutrino Mass Limit from Cyclotron Radiation Emission Spectroscopy.

The absolute scale of the neutrino mass plays a critical role in physics at every scale, from the subatomic to the cosmological. Measurements of the tritium end-point spectrum have provided the most precise direct limit on the neutrino mass scale. In this Letter, we present advances by Project 8 to the cyclotron radiation emission spectroscopy (CRES) technique culminating in the first frequency-based neutrino mass limit. With only a cm^{3}-scale physical detection volume, a limit of m_{ß}<155 eV/c^{2} (152 eV/c^{2}) is extracted from the background-free measurement of the continuous tritium beta spectrum in a Bayesian (frequentist) analysis. Using ^{83m}Kr calibration data, a resolution of 1.66±0.19 eV (FWHM) is measured, the detector response model is validated, and the efficiency is characterized over the multi-keV tritium analysis window. These measurements establish the potential of CRES for a high-sensitivity next-generation direct neutrino mass experiment featuring low background and high resolution.

Experimental limit on optical-photon coupling to light neutral scalar bosons.

We report on the first results of a sensitive search for scalar coupling of photons to a light neutral boson in the mass range of approximately 1.0 meV (milli-electron volts) and coupling strength greater than 10(-6) GeV(-1) using optical photons. This was a photon regeneration experiment using the "light shining through a wall" technique in which laser light was passed through a strong magnetic field upstream of an optical beam dump; regenerated laser light was then searched for downstream of a second magnetic field region optically shielded from the former. Our results show no evidence for scalar coupling in this region of parameter space.

Widespread neonatal brain damage following calcium channel blockade.

An abundance of evidence exists that shows calcium channel blockade promotes injury in cultured neurons. However, few studies have addressed the in vivo toxicity of such agents. We now show that the L-type calcium channel antagonist nimodipine promotes widespread and robust injury throughout the neonatal rat brain, in an age-dependent manner. Using both isolated neuronal as well as brain slice approaches, we address mechanisms behind such injury. These expanded studies show a consistent pattern of injury using a variety of agents that lower intracellular calcium. Collectively, these observations indicate that postnatal brain development represents a transitional period for still developing neurons, from being highly sensitive to reductions in intracellular calcium to being less vulnerable to such changes. These observations directly relate to current therapeutic strategies targeting neonatal brain injury.

Treatment costs of directly observed therapy and traditional therapy for Mycobacterium tuberculosis: a comparative analysis.

OBJECTIVE: Treatment of tuberculosis is a time-consuming and expensive process, often complicated by patient non-adherence. Directly observed therapy (DOT), an out-patient management strategy designed to ensure adherence, is not widely used because it is perceived to be too expensive. This study compared costs of tuberculosis treatment in DOT to the same factors in traditional therapy. DESIGN: A retrospective economic evaluation of 659 tuberculosis cases was reported to a major metropolitan county public health department between 1980 and 1994. Out-patient costs, in-patient costs and the cost impact of relapse and acquired resistance were estimated in 1995 dollars. RESULTS: Treatment costs were lower with DOT: $15,670 per case for in-patient care and $700 per case for out-patient care (P < 0.001). These cost differences resulted from shorter therapy duration (334 vs 550 days), fewer patient hospitalizations (58 vs 75%) and shorter hospital stays (26 vs 55 days per hospitalized patient). Relapse or acquired resistance occurred in 10.9% of patients and accounted for 35.7% of cost with traditional therapy, as compared to 1.2% of patients and 6.0% of cost with observed therapy. CONCLUSIONS: Directly observed therapy is less costly than traditional therapy.

Chronic fatigue complaints in primary care: incidence and diagnostic patterns.

The complaint of chronic fatigue is ubiquitous in the primary care setting. Because of the nonspecific nature of chronic fatigue, practitioners do not focus on this complaint. Furthermore, most physicians use a problem-based approach. Such a prematurely narrowed focus could overlook the chronic fatigue complaint. Omissions in the data collection process would prove this oversight. Therefore, we postulated that a retrospective review of evaluations for chronic fatigue would demonstrate significant categorical deficiencies. These deficiencies would indicate a problem focus different than the chronic fatigue complaint itself. The authors reviewed the current literature to establish historical, physical, and laboratory findings pertinent to the evaluation of chronic fatigue. Six major categories and the associated data elements were identified for use in analyzing patient records. The patient records from the preceding 6 months were reviewed to find those containing a complaint of chronic fatigue. These records were analyzed to determine if a complete data set had been sought and if an associated diagnosis was made. A total of 425 consecutive charts from an academic family practice clinic were retrospectively reviewed; 9.9% (42) mentioned chronic fatigue. Physicians were lax in performing the mental status and physical examinations; taking the patient's psychiatric and sleep history, as well as the history of chief complaint; and ordering laboratory evaluations. The physician diagnoses included: depression (40.4%), nonspecific fatigue (35.7%), general medical disorders (16.6%), chronic fatigue syndrome (2.4%), fibromyalgia (2.4%), and sleep apnea (2.4%). From these data, the investigators conclude that the workup for chronic fatigue is often incomplete or lacks documentation. This oversight is likely due to a problem focus not directed at the chronic fatigue complaints. Also complicating the evaluation process are the multiple associated disorders, the prevalence of the complaint, and cost/benefit issues facing the primary care physician.

The effect of directly observed therapy on the rates of drug resistance and relapse in tuberculosis.

BACKGROUND: Tuberculosis has reemerged as an important public health problem, and the frequency of drug resistance is increasing. A major reason for the development of resistant infections and relapse is poor compliance with medical regimens. In Tarrant County, Texas, we initiated a program of universal directly observed treatment for tuberculosis. We report the effect of the program on the rates of primary and acquired drug resistance and relapse among patients with tuberculosis. METHODS: We collected information on all patients with positive cultures for Mycobacterium tuberculosis in Tarrant County from January 1, 1980, through December 31, 1992. Through October 1986, patients received a traditional, unsupervised drug regimen. Beginning in November 1986, nearly all patients received therapy under direct observation by health care personnel. RESULTS: A total of 407 episodes in which patients received traditional treatment for tuberculosis (January 1980 through October 1986) were compared with 581 episodes in which therapy was directly observed (November 1986 through December 1992). Despite higher rates of intravenous drug use and homelessness and an increasing rate of tuberculosis during this 13-year period, the frequency of primary drug resistance decreased from 13.0 percent to 6.7 percent (P < 0.001) after the institution of direct observation of therapy, and the frequency of acquired resistance declined from 14.0 percent to 2.1 percent (P < 0.001). The relapse rate decreased from 20.9 percent to 5.5 percent (P < 0.001), and the number of relapses with multidrug-resistant organisms decreased from 25 to 5 (P < 0.001). CONCLUSIONS: The administration of therapy for M. tuberculosis infection under direct observation leads to significant reductions in the frequency of primary drug resistance, acquired drug resistance, and relapse.

Exogenous lipoid pneumonia due to nasal application of petroleum jelly.

We describe a patient who presented with a history of unexplained exertional dyspnea and pulmonary infiltrates. She was evaluated for interstitial lung disease, presumed to be idiopathic and underwent an open lung biopsy. The pathologic findings were compatible with exogenous lipoid pneumonia and her history revealed longstanding use of intranasal petroleum jelly (Vaseline) at bedtime.