MULTIDIMENSIONAL OPTIMAL DROOP CONTROL FOR WIND RESOURCES IN DC MICROGRIDS

Two important and upcoming technologies, microgrids and electricity generation from wind resources, are increasingly being combined. Various control strategies can be implemented, and droop control provides a simple option without requiring communication between microgrid components. Eliminating the single source of potential failure around the communication system is especially important in remote, islanded microgrids, which are considered in this work. However, traditional droop control does not allow the microgrid to utilize much of the power available from the wind. This dissertation presents a novel droop control strategy, which implements a droop surface in higher dimension than the traditional strategy. The droop control relationship then depends on two variables: the dc microgrid bus voltage, and the wind speed at the current time. An approach for optimizing this droop control surface in order to meet a given objective, for example utilizing all of the power available from a wind resource, is proposed and demonstrated. Various cases are used to test the proposed optimal high dimension droop control method, and demonstrate its function. First, the use of linear multidimensional droop control without optimization is demonstrated through simulation. Next, an optimal high dimension droop control surface is implemented with a simple dc microgrid containing two sources and one load. Various cases for changing load and wind speed are investigated using simulation and hardware-in-the-loop techniques. Optimal multidimensional droop control is demonstrated with a wind resource in a full dc microgrid example, containing an energy storage device as well as multiple sources and loads. Finally, the optimal high dimension droop control method is applied with a solar resource, and using a load model developed for a military patrol base application. The operation of the proposed control is again investigated using simulation and hardware-in-the-loop techniques.

Beyond words: Sensory properties of depressive thoughts

Verbal thoughts (such as negative cognitions) and sensory phenomena (such as visual mental imagery) are usually conceptualised as distinct mental experiences. The present study examined to what extent depressive thoughts are accompanied by sensory experiences and how this is associated with symptom severity, insight of illness and quality of life. A large sample of mildly to moderately depressed patients (N = 356) was recruited from multiple sources and asked about sensory properties of their depressive thoughts in an online study. Diagnostic status and symptom severity were established over a telephone interview with trained raters. Sensory properties of negative thoughts were reported by 56.5% of the sample (i.e., sensation in at least one sensory modality). The highest prevalence was seen for bodily (39.6%) followed by auditory (30.6%) and visual (27.2%) sensations. Patients reporting sensory properties of thoughts showed more severe psychopathological symptoms than those who did not. The degree of perceptuality was marginally associated with quality of life. The findings support the notion that depressive thoughts are not only verbal but commonly accompanied by sensory experiences. The perceptuality of depressive thoughts and the resulting sense of authenticity may contribute to the emotional impact and pervasiveness of such thoughts, making them difficult to dismiss for their holder.

Epoetin and Darbepoetin for Managing Anemia in Patients Undergoing Cancer Treatment: Comparative Effectiveness Update

Objectives: To update the 2006 systematic review of the comparative benefits and harms of erythropoiesis-stimulating agent (ESA) strategies and non-ESA strategies to manage anemia in patients undergoing chemotherapy and/or radiation for malignancy (excluding myelodysplastic syndrome and acute leukemia), including the impact of alternative thresholds for initiating treatment and optimal duration of therapy. Data sources: Literature searches were updated in electronic databases (n=3), conference proceedings (n=3), and Food and Drug Administration transcripts. Multiple sources (n=13) were searched for potential gray literature. A primary source for current survival evidence was a recently published individual patient data meta-analysis. In that meta-analysis, patient data were obtained from investigators for studies enrolling more than 50 patients per arm. Because those data constitute the most currently available data for this update, as well as the source for on-study (active treatment) mortality data, we limited inclusion in the current report to studies enrolling more than 50 patients per arm to avoid potential differential endpoint ascertainment in smaller studies. Review methods: Title and abstract screening was performed by one or two (to resolve uncertainty) reviewers; potentially included publications were reviewed in full text. Two or three (to resolve disagreements) reviewers assessed trial quality. Results were independently verified and pooled for outcomes of interest. The balance of benefits and harms was examined in a decision model. Results: We evaluated evidence from 5 trials directly comparing darbepoetin with epoetin, 41 trials comparing epoetin with control, and 8 trials comparing darbepoetin with control; 5 trials evaluated early versus late (delay until Hb ≤9 to 11 g/dL) treatment. Trials varied according to duration, tumor types, cancer therapy, trial quality, iron supplementation, baseline hemoglobin, ESA dosing frequency (and therefore amount per dose), and dose escalation. ESAs decreased the risk of transfusion (pooled relative risk [RR], 0.58; 95% confidence interval [CI], 0.53 to 0.64; I2 = 51%; 38 trials) without evidence of meaningful difference between epoetin and darbepoetin. Thromboembolic event rates were higher in ESA-treated patients (pooled RR, 1.51; 95% CI, 1.30 to 1.74; I2 = 0%; 37 trials) without difference between epoetin and darbepoetin. In 14 trials reporting the Functional Assessment of Cancer Therapy (FACT)-Fatigue subscale, the most common patient-reported outcome, scores decreased by −0.6 in control arms (95% CI, −6.4 to 5.2; I2 = 0%) and increased by 2.1 in ESA arms (95% CI, −3.9 to 8.1; I2 = 0%). There were fewer thromboembolic and on-study mortality adverse events when ESA treatment was delayed until baseline Hb was less than 10 g/dL, in keeping with current treatment practice, but the difference in effect from early treatment was not significant, and the evidence was limited and insufficient for conclusions. No evidence informed optimal duration of therapy. Mortality was increased during the on-study period (pooled hazard ratio [HR], 1.17; 95% CI, 1.04 to 1.31; I2 = 0%; 37 trials). There was one additional death for every 59 treated patients when the control arm on-study mortality was 10 percent and one additional death for every 588 treated patients when the control-arm on-study mortality was 1 percent. A cohort decision model yielded a consistent result—greater loss of life-years when control arm on-study mortality was higher. There was no discernible increase in mortality with ESA use over the longest available followup (pooled HR, 1.04; 95% CI, 0.99 to 1.10; I2 = 38%; 44 trials), but many trials did not include an overall survival endpoint and potential time-dependent confounding was not considered. Conclusions: Results of this update were consistent with the 2006 review. ESAs reduced the need for transfusions and increased the risk of thromboembolism. FACT-Fatigue scores were better with ESA use but the magnitude was less than the minimal clinically important difference. An increase in mortality accompanied the use of ESAs. An important unanswered question is whether dosing practices and overall ESA exposure might influence harms.

Birth defects among surviving children under seven years of age in Tianjin, China

Birth defects are a leading cause of infant mortality in the developed countries. They are also of increasing concern in many developing countries, such as China. However, prevalence and causes of birth defects in China are inadequately understood.^ The purpose of the present study was to estimated prevalence of birth defects in surviving children under seven years of age in Tianjin, China and investigate determinants of birth defects in the study area.^ The present study took place in Tianjin, China in 1986, involving 22,081 surviving children under seven years of age. Children with birth defects were ascertained through physical examinations by physicians during household visits and ascertainment of birth defects was verified through multiple sources. Of 22,081 surviving children, 524 had birth defects (23.7 per 1,000). The study noted a striking discrepancy in the prevalence of birth defects between urban and rural area. The prevalence of birth defects was 16.3 per 1,000 in the urban and 33.2 per 1,000 in the rural area.^ Using cases of birth defects ascertained from surviving children, a case-control study was carried out. The study observed that first-trimester maternal flu was associated with increased risk of both major and minor birth defects in children after controlling for other maternal factors (adjusted odds ratio (OR) = 8.7, 95% confidence interval (CI) = 4.3-17.3; OR = 3.6, 95% CI = 1.7-7.5). This association could be biased by different reporting of exposure between mothers of children with birth defects and mothers of children without defects. This study indicated that maternal flu was also associated with congenital heart defects and polydactyly after controlling for other maternal factors (adjusted OR = 32.3, 95% CI = 13.3-78.3; adjusted OR = 5.5, 95% CI = 1.1-27.7). The associations remained when affected controls (children with similar birth defects other than congenital heart defects or polydactyly) were used (adjusted OR = 4.3, 95% CI = 1.2-15.3; OR = 1.4, 95% CI = 1.4-7.9). A weak association between first-trimester vaginal bleeding and selected groups of birth defects was found in this study, but the association may be confounded by other factors. Maternal smoking during pregnancy was modestly associated with cleft lip with or without cleft palate (OR = 1.4, 95% = 0.4-4.9), but the association may be due to chance. Some major limitations in this study warrant caution in interpretation of the findings, especially the causal relation. ^

Decoding Delay Minimization in Inter-Session Network Coding

Intra-session network coding has been shown to offer significant gains in terms of achievable throughput and delay in settings where one source multicasts data to several clients. In this paper, we consider a more general scenario where multiple sources transmit data to sets of clients over a wireline overlay network. We propose a novel framework for efficient rate allocation in networks where intermediate network nodes have the opportunity to combine packets from different sources using randomized network coding. We formulate the problem as the minimization of the average decoding delay in the client population and solve it with a gradient-based stochastic algorithm. Our optimized inter-session network coding solution is evaluated in different network topologies and is compared with basic intra-session network coding solutions. Our results show the benefits of proper coding decisions and effective rate allocation for lowering the decoding delay when the network is used by concurrent multicast sessions.

Objective consensus from decision trees

BackgroundConsensus-based approaches provide an alternative to evidence-based decision making, especially in situations where high-level evidence is limited. Our aim was to demonstrate a novel source of information, objective consensus based on recommendations in decision tree format from multiple sources.MethodsBased on nine sample recommendations in decision tree format a representative analysis was performed. The most common (mode) recommendations for each eventuality (each permutation of parameters) were determined. The same procedure was applied to real clinical recommendations for primary radiotherapy for prostate cancer. Data was collected from 16 radiation oncology centres, converted into decision tree format and analyzed in order to determine the objective consensus.ResultsBased on information from multiple sources in decision tree format, treatment recommendations can be assessed for every parameter combination. An objective consensus can be determined by means of mode recommendations without compromise or confrontation among the parties. In the clinical example involving prostate cancer therapy, three parameters were used with two cut-off values each (Gleason score, PSA, T-stage) resulting in a total of 27 possible combinations per decision tree. Despite significant variations among the recommendations, a mode recommendation could be found for specific combinations of parameters.ConclusionRecommendations represented as decision trees can serve as a basis for objective consensus among multiple parties.

NetCodCCN: a Network Coding approach for Content-Centric Networks

Content-Centric Networking (CCN) naturally supports multi-path communication, as it allows the simultaneous use of multiple interfaces (e.g. LTE and WiFi). When multiple sources and multiple clients are considered, the optimal set of distribution trees should be determined in order to optimally use all the available interfaces. This is not a trivial task, as it is a computationally intense procedure that should be done centrally. The need for central coordination can be removed by employing network coding, which also offers improved resiliency to errors and large throughput gains. In this paper, we propose NetCodCCN, a protocol for integrating network coding in CCN. In comparison to previous works proposing to enable network coding in CCN, NetCodCCN permit Interest aggregation and Interest pipelining, which reduce the data retrieval times. The experimental evaluation shows that the proposed protocol leads to significant improvements in terms of content retrieval delay compared to the original CCN. Our results demonstrate that the use of network coding adds robustness to losses and permits to exploit more efficiently the available network resources. The performance gains are verified for content retrieval in various network scenarios.

A simulation study on the statistical monitoring of condemnation rates from slaughterhouses for syndromic surveillance: an evaluation based on Swiss data

Syndromic surveillance (SyS) systems currently exploit various sources of health-related data, most of which are collected for purposes other than surveillance (e.g. economic). Several European SyS systems use data collected during meat inspection for syndromic surveillance of animal health, as some diseases may be more easily detected post-mortem than at their point of origin or during the ante-mortem inspection upon arrival at the slaughterhouse. In this paper we use simulation to evaluate the performance of a quasi-Poisson regression (also known as an improved Farrington) algorithm for the detection of disease outbreaks during post-mortem inspection of slaughtered animals. When parameterizing the algorithm based on the retrospective analyses of 6 years of historic data, the probability of detection was satisfactory for large (range 83-445 cases) outbreaks but poor for small (range 20-177 cases) outbreaks. Varying the amount of historical data used to fit the algorithm can help increasing the probability of detection for small outbreaks. However, while the use of a 0·975 quantile generated a low false-positive rate, in most cases, more than 50% of outbreak cases had already occurred at the time of detection. High variance observed in the whole carcass condemnations time-series, and lack of flexibility in terms of the temporal distribution of simulated outbreaks resulting from low reporting frequency (monthly), constitute major challenges for early detection of outbreaks in the livestock population based on meat inspection data. Reporting frequency should be increased in the future to improve timeliness of the SyS system while increased sensitivity may be achieved by integrating meat inspection data into a multivariate system simultaneously evaluating multiple sources of data on livestock health.

Syndromic surveillance at a long term shelter for persons displaced by hurricanes Katrina and Rita conducted by the San Antonio Metropolitan Health District

Background. Beginning September 2, 2005, San Antonio area shelters received approximately 12,700 evacuees from Hurricane Katrina. Two weeks later, another 12,000 evacuees from Hurricane Rita arrived. By mid-October, 2005, the in-shelter population was 1,000 people. There was concern regarding the potential for spread of infectious diseases in the shelter. San Antonio Metropolitan Health District (SAMHD) established a syndromic surveillance system with Comprehensive Health Services (CHS) who provided on-site health care. CHS was in daily contact with SAMHD to report symptoms of concern until the shelter closed December 23, 2005. ^ Study type. The objective of this study was to assess the methods used and describe the practical considerations involved in establishing and managing a syndromic surveillance system, as established by the SAMHD in the long-term shelter clinic maintained by CHS for the hurricane evacuees. ^ Methods. Information and descriptive data used in this study was collected from multiple sources, primarily from the San Antonio Metropolitan Health District’s 2006 Report on Syndromic Surveillance of a Long-Term Shelter by Hausler & Rohr-Allegrini. SAMHD and CHS staff ensured that each clinic visit was recorded by date, demographic information, chief complaint and medical disposition. Logs were obtained daily and subsequently entered into a Microsoft Access database and analyzed in Excel. ^ Results. During a nine week period, 4,913 clinic visits were recorded, reviewed and later analyzed. Repeat visits comprised 93.0% of encounters. Chronic illnesses contributed to 21.7% of the visits. Approximately 54.0% were acute care encounters. Of all encounters, 17.3% had infectious disease potential as primarily gastrointestinal and respiratory syndromes. Evacuees accounted for 86% and staff 14% of all visits to the shelter clinic. There were 782 unduplicated individuals who sought services at the clinic, comprised of 63% (496) evacuees and 36% (278) staff members. Staff were more likely to frequent the clinic but for fewer visits each. ^ Conclusion. The presence of health care services and syndromic surveillance provided the opportunity to recognize, document and intervene in any disease outbreak at this long-term shelter. Constant vigilance allowed SAMHD to inform and reassure concerned people living and working in the shelter and living outside the shelter.^

AN EPIDEMIOLOGIC DESCRIPTION AND ANALYSIS OF LOST WORKDAY OCCUPATIONAL BURN INJURIES

Background research consisted of a hospital case series of all adult burn patients (n = 162) admitted to John Sealy Hospital's burn unit from January 1978 to June 1979. Comparisons between occupationally and nonoccupationally burned adults demonstrated that occupationally burned adults were significantly more likely to have been active in the burn injury event and to have changed jobs during the prior year. They were significantly less likely to have physical or mental problems which contributed to sustaining the burn injury. Comparisons between occupational and nonoccupational burn injury events concluded that occupational burn injury events were significantly more likely to involve multiple sources of energy, sparks as the source of ignition and gases as the source of combustion. Other salient characteristics of occupational burn injuries indicated that subsequent research should focus upon lost workday occupational burns and other injuries sustained by blue-collar petrochemical workers employed in Galveston County, Texas.^ Subsequent research consisted of a historical cohort study of occupational injuries sustained in 1979 by a cohort of blue-collar petrochemical workers (n = 1771) who belonged to O.C.A.W. Local 4-449 in Texas City, Texas. Specific cohort injury rates included 15.08 occupational injuries per 100 person work-years, 11.98 lost workday occupational injuries per 100 person work-years, and 1.64 lost workday occupational burn injuries per 100 person work-years. Salient results from this study indicate that burn injuries are a very important type (in terms of both frequency and severity) of occupational injury sustained by blue-collar petrochemical workers, pipefitters are at greatest risk of lost workday injuries and lost workday burn injuries, company-specific experiences are comparable for lost workday occupational injuries, differences among company-specific nonlost workday occupational injury experiences may not be "safety-related", and minimal job-specific experience may not place employees at greater risk of lost workday burn injuries.^

Network-based genome-wide association study of Crohn's disease

Genome-wide association studies (GWAS) have rapidly become a standard method for disease gene discovery. Many recent GWAS indicate that for most disorders, only a few common variants are implicated and the associated SNPs explain only a small fraction of the genetic risk. The current study incorporated gene network information into gene-based analysis of GWAS data for Crohn's disease (CD). The purpose was to develop statistical models to boost the power of identifying disease-associated genes and gene subnetworks by maximizing the use of existing biological knowledge from multiple sources. The results revealed that Markov random field (MRF) based mixture model incorporating direct neighborhood information from a single gene network is not efficient in identifying CD-related genes based on the GWAS data. The incorporation of solely direct neighborhood information might lead to the low efficiency of these models. Alternative MRF models looking beyond direct neighboring information are necessary to be developed in the future for the purpose of this study.^

INTEGRATIVE BIOMARKER IDENTIFICATION AND CLASSIFICATION USING HIGH THROUGHPUT ASSAYS

It is well accepted that tumorigenesis is a multi-step procedure involving aberrant functioning of genes regulating cell proliferation, differentiation, apoptosis, genome stability, angiogenesis and motility. To obtain a full understanding of tumorigenesis, it is necessary to collect information on all aspects of cell activity. Recent advances in high throughput technologies allow biologists to generate massive amounts of data, more than might have been imagined decades ago. These advances have made it possible to launch comprehensive projects such as (TCGA) and (ICGC) which systematically characterize the molecular fingerprints of cancer cells using gene expression, methylation, copy number, microRNA and SNP microarrays as well as next generation sequencing assays interrogating somatic mutation, insertion, deletion, translocation and structural rearrangements. Given the massive amount of data, a major challenge is to integrate information from multiple sources and formulate testable hypotheses. This thesis focuses on developing methodologies for integrative analyses of genomic assays profiled on the same set of samples. We have developed several novel methods for integrative biomarker identification and cancer classification. We introduce a regression-based approach to identify biomarkers predictive to therapy response or survival by integrating multiple assays including gene expression, methylation and copy number data through penalized regression. To identify key cancer-specific genes accounting for multiple mechanisms of regulation, we have developed the integIRTy software that provides robust and reliable inferences about gene alteration by automatically adjusting for sample heterogeneity as well as technical artifacts using Item Response Theory. To cope with the increasing need for accurate cancer diagnosis and individualized therapy, we have developed a robust and powerful algorithm called SIBER to systematically identify bimodally expressed genes using next generation RNAseq data. We have shown that prediction models built from these bimodal genes have the same accuracy as models built from all genes. Further, prediction models with dichotomized gene expression measurements based on their bimodal shapes still perform well. The effectiveness of outcome prediction using discretized signals paves the road for more accurate and interpretable cancer classification by integrating signals from multiple sources.

Tab. 1: Trace-element concentrations in ore samples collected from mercury mines and deposits in southwestern Alaska

A belt of small but numerous mercury deposits extends for about 500 km in the Kuskokwim River region of southwestern Alaska. The southwestern Alaska mercury belt is part of widespread mercury deposits of the circum Pacific region that are similar to other mercury deposits throughout the world because they are epithermal with formation temperatures of about 200 °C, the ore is dominantly cinnabar with Hg-Sb-As±Au geochemistry, and mineralized forms include vein, vein breccias, stockworks, replacements, and disseminations. The southwestern Alaska mercury belt has produced about 1400 t of mercury, which is small on an international scale. However, additional mercury deposits are likely to be discovered because the terrain is topographically low with significant vegetation cover. Anomalous concentrations of gold in cinnabar ore suggest that gold deposits are possible in higher temperature environments below some of the Alaska mercury deposits. We correlate mineralization of the southwestern Alaska mercury deposits with Late Cretaceous and early Tertiary igneous activity. Our 40Ar/39Ar ages of 70 ±3 Ma from hydrothermal sericites in the mercury deposits indicate a temporal association of igneous activity and mineralization. Furthermore, we suggest that our geological ancl geochemical data from the mercury deposits indicate that ore fluids were generated primarily in surrounding sedimentary wall rocks when they were cut by Late Cretaceous and early Tertiary intrusions. In our ore genesis model, igneous activity provided the heat to initiate dehydration reactions and expel fluids from hydrous minerals and formational waters in the surrounding sedimentary wall rocks, causing thermal convection and hydrothermal fluid flow through permeable rocks and along fractures and faults. Our isotopic data from sulfide and alteration minerals of the mercury deposits indicate that ore fluids were derived from multiple sources, with most ore fluids originating from the sedimentary wall rocks.

(Appendix A) Geochemical composition of snow and eolian mineral dust from Berkner Island ice sheet, Antarctica

The Sr and Nd isotopic composition of dust extracted from recent snow layers at the top of Berkner Island ice sheet (located within the Filchner-Ronne Ice Shelf at the southern end of the Weddell Sea) enables us, for the first time, to document dust provenance in Antarctica outside the East Antarctic Plateau (EAP) where all previous studies based on isotopic fingerprinting were carried out. Berkner dust displays an overall crust-like isotopic signature, characterized by more radiogenic 87Sr/86Sr and much less radiogenic 143Nd/144Nd compared to dust deposited on the EAP during glacial periods. Differences with EAP interglacial dust are not as marked but still significant, indicating that present-day Berkner dust provenance is distinct, at least to some extent, from that of the dust reaching the EAP. The fourteen snow-pit sub-seasonal samples that were obtained span a two-year period (2002-2003) and their dust Sr and Nd isotopic composition reveals that multiple sources are at play over a yearly time period. Southern South America, Patagonia in particular, likely accounts for part of the observed spring/summer dust deposition maxima, when isotopic composition is shifted towards 'younger' isotopic signatures. In the spring, possible additional inputs from Australian sources would also be supported by the data. Most of the year, however, the measured isotopic signatures would be best explained by a sustained background supply from putative local sources in East Antarctica, which carry old-crust-like isotopic fingerprints. Whether the restricted East Antarctic ice-free areas produce sufficient eolian material has yet to be substantiated however. The fact that large (> 5 µm) particles represent a significant fraction of the samples throughout the entire time-series supports scenarios that involve contributions from proximal sources, either in Patagonia and/or Antarctica (possibly including snow-free areas in the Antarctic Peninsula and other areas as well). This also indicates that additional dust transport, which does not reach the EAP, must occur at low-tropospheric levels to this coastal sector of Antarctica.