The next stage in the tuberculosis movement: A criticism and a suggestion

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Far Field Plume Distribution and Divergence for NEXT: DART Mission

In support of the Double Asteroid Redirection Test (DART) mission, laboratory measurements were made on the NEXT ion engine, which will be used for the spacecraft's in-space propulsion [1]. This study revisits a small range of mission-specific 2.7A throttle levels to understand the effect of in-flight flow rate variability, investigate intermediate throttle conditions, and improve measurement methodology. This paper specifically examines the far-field plume divergence and backflow ion flux distribution of the NEXT, while a companion paper examines the charge state distributions

Beyond genus statistics: a unifying approach to the morphology of cosmic structure

The genus statistics of isodensity contours has become a well-established tool in cosmology. In this Letter we place the genus in the wider framework of a complete family of morphological descriptors. These are known as the Minkowski functionals, and we here apply them for the first time to isodensity contours of a continuous random field. By taking two equivalent approaches, one through differential geometry, the other through integral geometry, we derive two complementary formulae suitable for numerically calculating the Minkowski functionals. As an example we apply them to simulated Gaussian random fields and compare the outcome to the analytically known results, demonstrating that both are indeed well suited for numerical evaluation. The code used for calculating all Minkowski functionals is available from the authors.Comment: 8 pages plus 1 figure; uses aaspp4.sty and flushrt.sty. Matches version accepted for publication in Ap. J. Let

Tuberculosis in children in India-II: Chemotherapy for tuberculosis

Tubercle bacilli readily become resistant to the common drugs, and resistant bacilli are more likely to proliferate if they are present in the patient at the start of treatment. So always use more than one drug. The only possible exception is prophylaxis for an asymptomatic case with a normal X-ray. CAUTION! (1) Never give intermittent (twice or thrice weekly) treatment unless every dose can be supervised by a health worker. Daily treatment is usually mandatory. (2) When you give more than one drug, give them both at the same time, so that high blood levels coincide; do not give one drug daily and the other drug less often. THE DOSES of the commonly used drugs for daily and intermittent treatment in children and adults are: lsoniazid (H) 5 mg/kg/24 hours if he is moderately ill and 10 mg/kg/24 hours if he is severely ill. The dose for a twice weekly course is 15 mg/kg. CAUTION! Opinions on the dose of isoniazid vary. Some consider 10 mg/kg/24 hours too much for an Indian child and always give 5 mg. Rifampicin (R) 10 mg/kg/24 hours, or 10 mg/kg twice weekly. Pyrazinamide (Z) 35 mg/kg/24 hours, 75 mg/kg twice weekly or 50 mg/kg thrice weekly, is an important drug for short course treatment, so try to include it whenever it is mentioned in the regimes below. Streptomycin (S) 10-20 mg/kg/24 hours, or 40 mg/kg twice weekly, to a total of not more than 0.75 g. Streptomycin is painful, so avoid it if you can. If you give it, inject in different places each day, because repeated injections into the same site are painful. Ethambutol (E) 25 mg/kg/24 hours for 2 months, then 15 mg/kg/24 hours. Avoid ethambutol in younger children (under 12); they are unable to complain of the early symptoms of retrobulbar neuritis (blindness). Thiacetazone (T) 4 mg/kg/24 hours to a maximum Of 150 mg; unsuitable for intermittent treatment

Tuberculosis in children in India-I

Tuberculosis is different in children. It involves many organs, instead of being the predominantly respiratory disease that it usually is in adults. Fortunately, it readily responds to treatment–if you diagnose it early enough and treat it for long enough! This is the problem. Unfortunately, tuberculosis causes such non-specific symptoms and signs, and you are so seldom able to isolate bacilli, that you may never be sure of the diagnosis. Even experts sometimes disagree. In India particularly, it is a disease of the poorest of the poor, but even in them it causes only a small proportion of their burden of morbidity. The great problem is to reach those infected. Of every thousand Indians, seven children and about twenty adults have active tuberculosis, and five of these adults are sputum positive. Only about half the 9 million in the community at any one time are ever diagnosed, and of these only about 13% complete their treatment, so there is a huge pool of infectious cases, half a million of whom die each year. Fortunately, the incidence of tuberculosis among children reporting to hospital is slowly decreasing, probably largely due to improved coverage with BCG

High prevalence of bronchiectasis is linked to HTLV-1-associated inflammatory disease.

BACKGROUND: Human T-lymphotropic virus type 1 (HTLV-1), a retrovirus, is the causative agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T-cell leukaemia/lymphoma (ATLL). The reported association with pulmonary disease such as bronchiectasis is less certain. METHODS: A retrospective case review of a HTLV-1 seropositive cohort attending a national referral centre. The cohort was categorised into HTLV-1 symptomatic patients (SPs) (ATLL, HAM/TSP, Strongyloidiasis and HTLV associated inflammatory disease (HAID)) and HTLV-1 asymptomatic carriers (ACs). The cohort was reviewed for diagnosis of bronchiectasis. RESULT: 34/246 ACs and 30/167 SPs had been investigated for respiratory symptoms by computer tomography (CT) with productive cough +/- recurrent chest infections the predominant indications. Bronchiectasis was diagnosed in one AC (1/246) and 13 SPs (2 HAID, 1 ATLL, 10 HAM/TSP) (13/167, RR 19.2 95 % CI 2.5-14.5, p = 0.004) with high resolution CT. In the multivariate analysis ethnicity (p = 0.02) and disease state (p < 0.001) were independent predictors for bronchiectasis. The relative risk of bronchiectasis in SPs was 19.2 (95 % CI 2.5-14.5, p = 0.004) and in HAM/TSP patients compared with all other categories 8.4 (95 % CI 2.7-26.1, p = 0.0002). Subjects not of African/Afro-Caribbean ethnicity had an increased prevalence of bronchiectasis (RR 3.45 95 % 1.2-9.7, p = 0.02). CONCLUSIONS: Bronchiectasis was common in the cohort (3.4 %). Risk factors were a prior diagnosis of HAM/TSP and ethnicity but not HTLV-1 viral load, age and gender. The spectrum of HTLV-associated disease should now include bronchiectasis and HTLV serology should be considered in patients with unexplained bronchiectasis

Thyroid-Hormone–Disrupting Chemicals: Evidence for Dose-Dependent Additivity or Synergism

Endocrine disruption from environmental contaminants has been linked to a broad spectrum of adverse outcomes. One concern about endocrine-disrupting xenobiotics is the potential for additive or synergistic (i.e., greater-than-additive) effects of mixtures. A short-term dosing model to examine the effects of environmental mixtures on thyroid homeostasis has been developed. Prototypic thyroid-disrupting chemicals (TDCs) such as dioxins, polychlorinated biphenyls (PCBs), and poly-brominated diphenyl ethers have been shown to alter thyroid hormone homeostasis in this model primarily by up-regulating hepatic catabolism of thyroid hormones via at least two mechanisms. Our present effort tested the hypothesis that a mixture of TDCs will affect serum total thyroxine (T(4)) concentrations in a dose-additive manner. Young female Long-Evans rats were dosed via gavage with 18 different polyyhalogenated aromatic hydrocarbons [2 dioxins, 4 dibenzofurans, and 12 PCBs, including dioxin-like and non-dioxin-like PCBs] for 4 consecutive days. Serum total T(4) was measured via radioimmunoassay in samples collected 24 hr after the last dose. Extensive dose–response functions (based on seven to nine doses per chemical) were determined for individual chemicals. A mixture was custom synthesized with the ratio of chemicals based on environmental concentrations. Serial dilutions of this mixture ranged from approximately background levels to 100-fold greater than background human daily intakes. Six serial dilutions of the mixture were tested in the same 4-day assay. Doses of individual chemicals that were associated with a 30% TH decrease from control (ED(30)), as well as predicted mixture outcomes were calculated using a flexible single-chemical-required method applicable to chemicals with differing dose thresholds and maximum-effect asymptotes. The single-chemical data were modeled without and with the mixture data to determine, respectively, the expected mixture response (the additivity model) and the experimentally observed mixture response (the empirical model). A likelihood-ratio test revealed statistically significant departure from dose additivity. There was no deviation from additivity at the lowest doses of the mixture, but there was a greater-than-additive effect at the three highest mixtures doses. At high doses the additivity model underpredicted the empirical effects by 2- to 3-fold. These are the first results to suggest dose-dependent additivity and synergism in TDCs that may act via different mechanisms in a complex mixture. The results imply that cumulative risk approaches be considered when assessing the risk of exposure to chemical mixtures that contain TDCs

Random Convex Hulls and Extreme Value Statistics

In this paper we study the statistical properties of convex hulls of $N$ random points in a plane chosen according to a given distribution. The points may be chosen independently or they may be correlated. After a non-exhaustive survey of the somewhat sporadic literature and diverse methods used in the random convex hull problem, we present a unifying approach, based on the notion of support function of a closed curve and the associated Cauchy's formulae, that allows us to compute exactly the mean perimeter and the mean area enclosed by the convex polygon both in case of independent as well as correlated points. Our method demonstrates a beautiful link between the random convex hull problem and the subject of extreme value statistics. As an example of correlated points, we study here in detail the case when the points represent the vertices of $n$ independent random walks. In the continuum time limit this reduces to $n$ independent planar Brownian trajectories for which we compute exactly, for all $n$, the mean perimeter and the mean area of their global convex hull. Our results have relevant applications in ecology in estimating the home range of a herd of animals. Some of these results were announced recently in a short communication [Phys. Rev. Lett. {\bf 103}, 140602 (2009)].Comment: 61 pages (pedagogical review); invited contribution to the special issue of J. Stat. Phys. celebrating the 50 years of Yeshiba/Rutgers meeting

Measurement of 30-Centimeter Ion Thruster Discharge Cathode Erosion

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76209/1/AIAA-22982-649.pd