Maritime threat response

This report was prepared by Systems Engineering and Analysis Cohort Nine (SEA-9) Maritime Threat Response, (MTR) team members.Background: The 2006 Naval Postgraduate School (NPS) Cross-Campus Integrated Study, titled “Maritime Threat Response” involved the combined effort of 7 NPS Systems Engineering students, 7 Singaporean Temasek Defense Systems Institute (TDSI) students, 12 students from the Total Ship Systems Engineering (TSSE) curriculum, and numerous NPS faculty members from different NPS departments. After receiving tasking provided by the Wayne E. Meyer Institute of Systems Engineering at NPS in support of the Office of the Assistant Secretary of Defense for Homeland Defense, the study examined ways to validate intelligence and respond to maritime terrorist attacks against United States coastal harbors and ports. Through assessment of likely harbors and waterways to base the study upon, the San Francisco Bay was selected as a representative test-bed for the integrated study. The NPS Systems Engineering and Analysis Cohort 9 (SEA-9) Maritime Threat Response (MTR) team, in conjunction with the TDSI students, used the Systems Engineering Lifecycle Process (SELP) [shown in Figure ES-1, p. xxiii ] as a systems engineering framework to conduct the multi-disciplinary study. While not actually fabricating any hardware, such a process was well-suited for tailoring to the team’s research efforts and project focus. The SELP was an iterative process used to bound and scope the MTR problem, determine needs, requirements, functions, and to design architecture alternatives to satisfy stakeholder needs and desires. The SoS approach taken [shown in Figure ES-2, p. xxiv ]enabled the team to apply a systematic approach to problem definition, needs analysis, requirements, analysis, functional analysis, and then architecture development and assessment.In the twenty-first century, the threat of asymmetric warfare in the form of terrorism is one of the most likely direct threats to the United States homeland. It has been recognized that perhaps the key element in protecting the continental United States from terrorist threats is obtaining intelligence of impending attacks in advance. Enormous amounts of resources are currently allocated to obtaining and parsing such intelligence. However, it remains a difficult problem to deal with such attacks once intelligence is obtained. In this context, the Maritime Threat Response Project has applied Systems Engineering processes to propose different cost-effective System of Systems (SoS) architecture solutions to surface-based terrorist threats emanating from the maritime domain. The project applied a five-year time horizon to provide near-term solutions to the prospective decision makers and take maximum advantage of commercial off-the-shelf (COTS) solutions and emphasize new Concepts of Operations (CONOPS) for existing systems. Results provided insight into requirements for interagency interactions in support of Maritime Security and demonstrated the criticality of timely and accurate intelligence in support of counterterror operations.This report was prepared for the Office of the Assistant Secretary of Defense for Homeland DefenseApproved for public release; distribution is unlimited

Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

A study on signature analyzer for design for test (DFT)

This paper takes a look at the use of linear feedback shift registers (LFSR's) as test pattern generators (TPG's) and signature analyzers for built-in self-test (BIST). We also propose a method to generate pseudorandom test patterns. The proposed method can generate longer sequences of the same set of test patterns

Reduce Membrane Fouling in a Novel Bio-Entrapped Membrane Reactor: Impact of Soluble Microbial Products

薄膜生物系統(MBR)目前已被廣泛應用於處理都市生活污水二級處理程序中，但MBR系統通常會有薄膜積垢、薄膜阻塞及滲流率衰減之現象與問題。此薄膜操作問題，一般被認為可能是經由二級生物處理出流水中懸浮顆粒、胞外聚合物(Extracellular Polymeric Substances, EPS)及溶解性胞外聚合物(Soluble Microbial Products, SMP)等所造成，致使薄膜過濾阻力(Filtration Resistance)上升及滲流率衰減。傳統生物處理程序會產生大量污泥與終沉池污泥沉降效果不佳等缺點，其中EPS和SMP已被確定為造成薄膜積垢主要原因。因此，固定生物處理程序(Bio-Entrapped Process, BER)及固定生物處理程序結合薄膜反應系統(Bio-Entrapped Membrane Reactor, BEMR)已被研究發展，本研究利用此技術具有較長生物污泥停留時間(Sludge Retention Time, SRT)技術、高密度污泥及污泥產率低及可同時去除有機物和氮等優點，進行與傳統薄膜生物系統(Conventional Membrane Bioreactor, CMBR)作比較探討 研究結果顯示，具較長污泥停留時間BER程序相較傳統活性污泥法能夠提高25%~30%薄膜過濾通量，並減少薄膜積垢速率，此外發現固定生物處理技術所產生之溶解性胞外聚合物(Soluble Microbial Products, SMP)相較傳統活性污泥法能夠降低約71%，且能提升薄膜反清洗後恢復速度。固定生物處理技術結合薄膜系統(Bio-Entrapped Membrane Reactor, BEMR) 以食品工業廢水進行薄膜積垢研究，結果顯示BEMR對於有機物和氨氮具有超過90%以上的去除效率，並可提升薄膜過濾時間、不易積垢及降低操作維護成本。以BEMR濾程可長達39天，相較CMBR濾程僅只有5天即需進行化學清洗，BEMR亦產生較少蛋白質和碳水化合物，分別約為34%-48%和16%-29%。長污泥停留時間為影響bio-fouling之重要因子，亦相對影響薄膜操作效能及EPS/SMP特性，而隨污泥停留時間增加SMP有明顯減少趨勢。此外本研究結果顯示，懸浮固體物和EPS並非造成薄膜積垢之主因，薄膜積垢主要積垢原因為SMP所造成，研究發現BEMR與CMBR中SMP之分子量主要介於10-100kDa，而主要化學組成中蛋白質分別佔約59%與64%，其中結果顯示SMP分子量介於10-100 kDa之成份會對薄膜產生嚴重積垢問題，其能輕易進入和黏附在薄膜孔徑進而造成薄膜內孔徑吸附阻塞。另外為了解蛋白質和碳水化合物對薄膜積垢之影響，分別利用了蛋白質(L-tyrosine, Protein)和碳水化合物(Glucose, Carbohydrate)進行薄膜積垢實驗，結果顯示在不同濃度比較下，蛋白質造成薄膜通量下降情形皆比碳水化合物較為嚴重。 固定生物處理技術和固定生物薄膜反應系統確實能有效改善傳統薄膜生物系統問題，如提高處理效率、減緩薄膜積垢、降低SMP濃度，並能增加產水效率及減少化學清洗頻率，降低操作成本。Membrane bioreactors (MBRs) have been widely adopted for secondary treatment of municipal wastewater in the past decade, especially in developed countries. However, a major issue of MBRs is the rapid decline of permeate flux due to a high level of biomass in the reactor that accelerates membrane fouling. High sludge concentration and extracellular polymeric substances (EPS) or soluble microbial products (SMP) have been determined to be the major factors affecting membrane bioreactor operation. Therefore, the development of a novel biological reactor that contains a lower concentration of biomass and SMP is warranted. The bio-entrapped reactor (BER) has been developed for treatment of various wastewaters to achieve high simultaneous removal of carbon and nitrogen, and that reduced suspended biomass and increased SRT in the reactor with the objectives to achieve high organics removal in a more facile operation with a short start-up period. Thus, the BER was coupled with membrane as bio-entrapped membrane reactor (BEMR) was investigated the SMP and their characteristics on membrane fouling in treating food processing wastewater, and also compared with conventional membrane bioreactor (CMBR) with the overall study goal is to reduce membrane fouling commonly encountered in MBRs. The results show that BER with a longer sludge retention time (SRT) has demonstrated that membrane filtration performed well and achieved an approximately 25%-30% higher filtration flux and better flux recovery after backwashing than the activated sludge process (ASP) system. The BEMR could remove the carbon and ammonia nitrogen with more than 90% under different hydraulic retention time (HRT). The novel BEMR sustained operation at constant permeate flux (20 LMH) that required seven times less frequent chemical cleaning than did the conventional membrane bioreactor. Membrane fouling was improved in the new reactor, which led to a longer membrane service period with the new reactor. As in the CMBR, rapid membrane fouling was attributed to increased production of biomass and SMP, this is because the BEMR produced less SMP than did CMBR (34%-48% less protein and 16%-29% less carbohydrate) due to slow-growing microorganisms with longer SRT in the BEMR. Further, results of this thesis also indicated that suspended solids and bound EPS unexpectedly played a negligible role in membrane fouling and the fouling was actually controlled by SMP, which proved the SMP was the major contributor or foulant to the membrane fouling. Both MBRs (BEMR and CMBR) produced SMP of 10-100 kDa primarily of protein (59% in BEMR and 64% in CMBR), which likely caused membrane pores clogging because the 10-100 kDa of SMP could easily penetrate to the membrane pores by adsorption in a 100 kDa membrane used in this work. The impact of protein and carbohydrate to the membrane fouling was also been found because, the findings with L-Tyrosine and glucose as the model foulants for protein and carbohydrate respectively showed that protein (L-Tyrosine) caused more severe permeate flux decline than carbohydrate (glucose). The conclusion stated that the bio-entrapped membrane reactor could really improve the MBR performance by reducing the membrane fouling and producing less concentration of SMP with conventional membrane bioreactor. Therefore, the new BEMR offers effective organics removal while reducing membrane fouling with the potential for improving and encountering the current problems faced by conventional MBR

Investigation of intertidal wetland sediment as a novel inoculation source for anaerobic saline wastewater treatment

10.1021/acs.est.5b00546Environmental Science and Technology49106231-623

Blue chip stocks are better, myth or fact? : the performance of blue chip indices (June 1979 - June 1994)

The key motivating factor that prompted us to engage in this project on the performance of the blue chip indices in the stock market stems from the recent increasing interest of Singaporeans in stocks investment. The successful issue of the Telecom shares was the historical step put forward by the government towards share-ownership. We propose the research on the performance ofblue chip indices because we feel that the project would help investors in deciding which stocks to invest and to confirm the belief that blue chip stocks are superior in performance. Blue chip stocks consist mainly of companies with strong fmancial position and high growth potential. Hence, investment in blue chip stocks may yield stable and lucrative dividends. A study is made on the performance of the DBS 50 Index (DBS 50), OCBC 30 Index (OCBC 30) and UOB Blue Chip Index (UOB Blue Chip) relative to the SES AllSingapore Index which is used as the market surrogate. Investigation covers 15 years from June 1979 to June 1994, partitioned into three equal sub-periods (June 1979- June 1984, June 1984-June 1989 and June 1989-June 1994) for scrutiny. In particular, the last sub-period will be the period of focus for the analysis of the market sector performance. The methodology involves regression analysis of the excess monthly returns of the three blue chip indices against that of the SES All-Singapore (The excess monthly returns were computed based on the closing indices as on the last trading day of each month).The results of which were used in computing three risk-adjusted performance measures: the Jensen, Treynor and Sharpe indices. The main regression of 15 years sees all the three blue chip indices having the same performance as the market or marginally outperformed the market. However, for the last sub-period, the indices computed show underperformance of the market. Individual market sectors returned mixed results for the period from June 1989 to June 1994. The Finance sector showed the greatest outperformance of the market for this period while the Industrial & Commercial sector and the Hotel sector marginally underperformed the market. For the Property sector, the Jensen and Treynor indices computed show a marginal overperformance of the market, whereas the Sharpe index shows an underperformance of the market by 0.4 %. The blue chip indices are shown to have outperformed the market over the last 15 years - a fmancially rewarding experience for any investor in blue chip stocks during the period.ACCOUNTANC