Design of a device to remove lunar dust from space suits for the proposed lunar base

The National Aeronautics and Space Administration plans to begin construction of a lunar base soon after the turn of the century. During the Apollo missions, lunar dust proved to be a problem because the dust adhered to all exposed material surfaces. Since lunar dust will be a problem during the establishment and operation of this base, the need exists for a device to remove the dust from space suits before the astronauts enter clean environments. The physical properties of lunar dust were characterized and energy methods for removing the dust were identified. Eight alternate designs were developed to remove the dust. The final design uses a brush and gas jet to remove the dust. The brush bristles are made from Kevlar fibers and the gas jet uses pressurized carbon dioxide from a portable tank. A throttling valve allows variable gas flow. Also, the tank is insulated with Kapton and electrically heated to prevent condensation of the carbon dioxide when the tank is exposed to the cold (- 240 F) lunar night

Modelling the intervention effect of opioid agonist treatment on multiple mortality outcomes in people who inject drugs:a three-setting analysis

BACKGROUND: Opioid agonist treatment (OAT) reduces many of the harms associated with opioid dependence. We use mathematical modelling to comprehensively evaluate the overall health benefits of OAT among people who inject drugs (PWID) in Kentucky (USA), Kyiv (Ukraine), and Tehran (Iran). METHODS: We developed a dynamic model of HIV and HCV transmission, incarceration, and mortality through overdose, injury, suicide, disease-related or other causes. The model was calibrated to site-specific data using Bayesian methods. We evaluated ‘preventable drug-related deaths’ (‘pDRD’: HIV/HCV/overdose/suicide/injury) averted over 2020-2040 for four scenarios, added incrementally, compared to a scenario without OAT: existing OAT coverage (setting dependent; community: 4-11%; prison: 0-40%); scaling-up community OAT to 40% coverage; increasing average OAT duration from 4-14 months to 2 years; and scaling-up prison-based OAT. OUTCOMES: Drug-related harms contribute differentially to mortality across settings: overdose contributes 27-47% (range of median projections) of pDRDs over 2020-2040, suicide 6-17%, injury 3-17%, HIV 0-59% and HCV 2-18%. Existing OAT coverage in Tehran (31%) could have substantial impact, averting 13% pDRDs, but will have negligible impact (<2%) in Kyiv and Kentucky due to low OAT coverage (<4%). Scaling-up community OAT to 40% could avert 12-24% pDRDs, including 13-19% of overdose deaths, with greater impact in settings with significant HIV mortality (Tehran and Kyiv). Improving OAT retention and providing prison-based OAT would have significant additional impact, averting 27-48% pDRDs. INTERPRETATION: OAT can substantially reduce drug-related harms, particularly in settings with HIV epidemics among PWID. Maximising these impacts requires research and investment into achieving higher coverage, longer retention and provision of OAT in prisons and the community. FUNDING: UK NIHR, NID

Incarceration history and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis

Background People who inject drugs (PWID) experience a high prevalence of incarceration and might be at high risk of HIV and hepatitis C virus (HCV) infection during or after incarceration. We aimed to assess whether incarceration history elevates HIV or HCV acquisition risk among PWID. Methods In this systematic review and meta-analysis, we searched MEDLINE, Embase, and PsycINFO databases for studies in any language published from Jan 1, 2000 until June 13, 2017 assessing HIV or HCV incidence among PWID. We included studies that measured HIV or HCV incidence among community-recruited PWID. We included only studies reporting original results and excluded studies that evaluated incident infections by self-report. We contacted authors of cohort studies that met the inclusion or exclusion criteria, but that did not report on the outcomes of interest, to request data. We extracted and pooled data from the included studies using random-effects meta-analyses to quantify the associations between recent (past 3, 6, or 12 months or since last follow-up) or past incarceration and HIV or HCV acquisition (primary infection or reinfection) risk among PWID. We assessed the risk of bias of included studies using the Newcastle-Ottawa Scale. Between-study heterogeneity was evaluated using the I2 statistic and the P-value for heterogeneity. Findings We included published results from 20 studies and unpublished results from 21 studies. These studies originated from Australasia, western and eastern Europe, North and Latin America, and east and southeast Asia. Recent incarceration was associated with an 81% (relative risk [RR] 1·81, 95% CI 1·40–2·34) increase in HIV acquisition risk, with moderate heterogeneity between studies (I2=63·5%; p=0·001), and a 62% (RR 1·62, 95% CI 1·28–2·05) increase in HCV acquisition risk, also with moderate heterogeneity between studies (I2=57·3%; p=0·002). Past incarceration was associated with a 25% increase in HIV (RR 1·25, 95% CI 0·94–1·65) and a 21% increase in HCV (1·21, 1·02–1·43) acquisition risk. Interpretation Incarceration is associated with substantial short-term increases in HIV and HCV acquisition risk among PWID and could be a significant driver of HCV and HIV transmission among PWID. These findings support the need for developing novel interventions to minimise the risk of HCV and HIV acquisition, including addressing structural risks associated with drug laws and excessive incarceration of PWID

Harmful algal blooms and eutrophication : examining linkages from selected coastal regions of the United States

Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Harmful Algae 8 (2008): 39-53, doi:10.1016/j.hal.2008.08.017.Coastal waters of the United States (U.S.) are subject to many of the major harmful algal bloom (HAB) poisoning syndromes and impacts. These include paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), ciguatera fish poisoning (CFP) and various other HAB phenomena such as fish kills, loss of submerged vegetation, shellfish mortalities, and widespread marine mammal mortalities. Here, the occurrences of selected HABs in a selected set of regions are described in terms of their relationship to eutrophication, illustrating a range of responses. Evidence suggestive of changes in the frequency, extent or magnitude of HABs in these areas is explored in the context of the nutrient sources underlying those blooms, both natural and anthropogenic. In some regions of the U.S., the linkages between HABs and eutrophication are clear and well documented, whereas in others, information is limited, thereby highlighting important areas for further research.Support was provided through the Woods Hole Center for Oceans and Human Health (to DMA), National Science Foundation (NSF) grants OCE-9808173 and OCE-0430724 (to DMA), OCE-0234587 (to WPC), OCE04-32479 (to MLP), OCE-0138544 (to RMK), OCE-9981617 (to PMG); National Institute of Environmental Health Sciences (NIEHS) grants P50ES012742-01 (to DMA) and P50ES012740 (to MLP); NOAA Grants NA96OP0099 (to DMA), NA16OP1450 (to VLT), NA96P00084 (to GAV and CAH), NA160C2936 and NA108H-C (to RMK), NA860P0493 and NA04NOS4780241 (to PMG), NA04NOS4780239-02 (to RMK), NA06NOS4780245 (to DWT). Support was also provided from the West Coast Center for Oceans and Human Health (to VLT and WPC), USEPA Grant CR826792-01-0 (to GAV and CAH), and the State of Florida Grant S7701617826 (to GAV and CAH)

Enhanced buried UXO detection via GPR/EMI data fusion

© 2016 SPIE. This paper investigates the enhancements to detection of buried unexploded ordinances achieved by combining ground penetrating radar (GPR) data with electromagnetic induction (EMI) data. Novel features from both the GPR and the EMI sensors are concatenated as a long feature vector, on which a non-parametric classifier is then trained. The classifier is a boosting classifier based on tree classifiers, which allows for disparate feature values. The fusion algorithm was applied to a government-provided dataset from an outdoor testing site, and significant performance enhancements were obtained relative to classifiers trained solely on the GPR or EMI data. It is shown that the performance enhancements come from a combination of improvements in detection and in clutter rejection

GPR anomaly detection with robust principal component analysis

This paper investigates the application of Robust Principal Component Analysis (RPCA) to ground penetrating radar as a means to improve GPR anomaly detection. The method consists of a preprocessing routine to smoothly align the ground and remove the ground response (haircut), followed by mapping to the frequency domain, applying RPCA, and then mapping the sparse component of the RPCA decomposition back to the time domain. A prescreener is then applied to the time-domain sparse component to perform anomaly detection. The emphasis of the RPCA algorithm on sparsity has the effect of significantly increasing the apparent signal-to-clutter ratio (SCR) as compared to the original data, thereby enabling improved anomaly detection. This method is compared to detrending (spatial-mean removal) and classical principal component analysis (PCA), and the RPCA-based processing is seen to provide substantial improvements in the apparent SCR over both of these alternative processing schemes. In particular, the algorithm has been applied to both field collected impulse GPR data and has shown significant improvement in terms of the ROC curve relative to detrending and PCA

Emergency general surgery in Rwandan district hospitals: a cross-sectional study of spectrum, management, and patient outcomes

Background: Management of emergency general surgical conditions remains a challenge in rural sub-Saharan Africa due to issues such as insufficient human capacity and infrastructure. This study describes the burden of emergency general surgical conditions and the ability to provide care for these conditions at three rural district hospitals in Rwanda. Methods: This retrospective cross-sectional study included all patients presenting to Butaro, Kirehe and Rwinkwavu District Hospitals between January 1st 2015 and December 31st 2015 with emergency general surgical conditions, defined as non-traumatic, non-obstetric acute care surgical conditions. We describe patient demographics, clinical characteristics, management and outcomes. Results: In 2015, 356 patients presented with emergency general surgical conditions. The majority were male (57.2%) and adults aged 15–60 years (54.5%). The most common diagnostic group was soft tissue infections (71.6%), followed by acute abdominal conditions (14.3%). The median length of symptoms prior to diagnosis differed significantly by diagnosis type (p < 0.001), with the shortest being urological emergencies at 1.5 days (interquartile range (IQR):1, 6) and the longest being complicated hernia at 17.5 days (IQR: 1, 208). Of all patients, 54% were operated on at the district hospital, either by a general surgeon or general practitioner. Patients were more likely to receive surgery if they presented to a hospital with a general surgeon compared to a hospital with only general practitioners (75% vs 43%, p < 0.001). In addition, the general surgeon was more likely to treat patients with complex diagnoses such as acute abdominal conditions (33.3% vs 4.1%, p < 0.001) compared to general practitioners. For patients who received surgery, 73.3% had no postoperative complications and 3.2% died. Conclusion: While acute abdominal conditions are often considered the most common emergency general surgical condition in sub-Saharan Africa, soft tissue infections were the most common in our setting. This could represent a true difference in epidemiology in rural settings compared to referral facilities in urban settings. Patients were more likely to receive an operation in a hospital with a general surgeon as opposed to a general practitioner. This provides evidence to support increasing the surgical workforce in district hospitals in order to increase surgical availability for patients