Lifeguard: Local Health Awareness for More Accurate Failure Detection

SWIM is a peer-to-peer group membership protocol with attractive scaling and robustness properties. However, slow message processing can cause SWIM to mark healthy members as failed (so called false positive failure detection), despite inclusion of a mechanism to avoid this. We identify the properties of SWIM that lead to the problem, and propose Lifeguard, a set of extensions to SWIM which consider that the local failure detector module may be at fault, via the concept of local health. We evaluate this approach in a precisely controlled environment and validate it in a real-world scenario, showing that it drastically reduces the rate of false positives. The false positive rate and detection time for true failures can be reduced simultaneously, compared to the baseline levels of SWIM

Estimating evolutionary dynamics of cleavage site peptides among H5HA avian influenza employing mathematical information theory approaches

Estimating evolutionary conservation of cleavage site peptides among HA protein of all strains facilitates vaccine development against pandemic influenza. Conserved epitopes may be useful for diagnosis of animals infected with the influenza virus, and preventing their spread in other regions [ 1]. In the preliminary stage of this study, in silico analysis of hemagglutinin was applied to predict potential cleavage sites of each strain employing SigCleave [2] and SignalP 3.0 server [3]. The second stage of the study focused on analyzing the structure of connecting peptides of hemagglutinin cleavage sites based on the availability of the existing experimental data. Our result divulges higher frequency of base amino acids, essential for processing by the cellular protease, among pathogenic strains compared with non/low pathogenic strains. In addition, two complementary methods for identifying conserved amino acids were applied: statistical entropy based method, possibly the most sensitive tool to estimate the diversity of peptides [5], and relative entropy estimation. Analysis of both methods demonstrates that the connecting peptide of HA cleavage site of AIV in the United States were highly conserved over long periods of time. Entropy values aid to select those sequences that have the highest potential for mutation in a broad spectrum of avian population. Position 340 among our group of strains with the entropy value of 0.877928 has the highest bit of information value where highly conserved positions are those with

Iranian Cottonseed Meal Varieties As Substitute For Soybean Meal In Rainbow Trout(Oncorhynchus Mykiss) Feeds

This study was set up to investigate the nutritional value and the optimum inclusion level of several Iranian cottonseed meals i.e. var. Pak, Sahel and Akra (CSMP, CSMS, and CSMA) as a substitute for soybean meal (SBM) in rainbow trout (Oncorhynchus mykiss) feed. Apparent digestibility coefficients (ADC) were calculated in experiment 1 by using an indigestible marker. At the end of this experiment, the ADCs of CSMP, CSMS, CSMA and SBM were measured. Results showed that ADC values for most nutrients of CSMP, CSMS, and CSMA were different from those of SBM and when the varities were compared; ADC values for CSMP (62.7% from DM and 82.4% for CP and 66.6% for crude fat) were higher than the two other CSM varieties i.e. CSMS and CSMA. Three separate studies were carried out to investigate the nutritional value of each Iranian cottonseed meal varieties ( CSM) as soybean meal substitute in quality low cost rainbow trout feeds. Six formulated feeds consisting different substitution levels (0, 20, 40, 60, 80, 100%) of SBM with CSMP, CSMS, and CSMA, respectively, were fed to a total of 540 rainbow trout with initial mean body weight of 50 ± 5 g. Fish were randomly stocked into eighteen 100 L. fiberglass tanks with 30 fish per tank and 3 tanks per diet and fed to apparent satiation 3 times a day and 7 days per week fo

Book review: The end of representativepolitics by Simon Tormey

In The End of Representative Politics, Simon Tormey challenges the assumption that politics and democracy are ‘dead’, blighted by chronic distrust of the political class and undermined by the perceived failure of representative democracy to secure social justice. As Tormey instead points towards emergent forms of ‘subterranean’ politics indicative of a ‘post-representative’ era, Ali Dadgar argues that The End of Representative Politics proposes a novel and informative expansion of the scope of ‘democracy’ and ‘politics’ in the contemporary moment

Understanding Radiation Resistance in Head and Neck Tumor Xenografts Using Diffuse Reflectance and Raman Spectroscopy

Each year, 800,000 new patients are diagnosed with head and neck squamous cell carcinoma (HNSCC), a majority of whom are treated with a combination of daily fractions of radiation and weekly chemotherapy sessions for up to seven weeks. Current methods to evaluate treatment response of individual patients are limited to anatomical measurements of tumor burden using CT scan or MRI 4-8 weeks after completion of treatment. However, earlier knowledge of radiation-response prior to or at early days after commencement of therapy can aid oncologist with escalating and de-escalating treatment plans for exceptionally non-responding and responding patients. Such a knowledge can be only be gained if proper understanding of radiation-induced physiological and biomolecular changes is established and associated with treatment response. This dissertation presents two quantitative optical spectroscopic methods that can provide snapshots of tumor physiology and biomolecular content which can be used as biomarkers of treatment response. Because tumor hypoxia has been linked to poor treatment outcome, we employed diffuse reflectance spectroscopy to measure vascular oxygen saturation. In chapter 2, we first investigated the sensitivity of diffuse reflectance spectroscopy to tumor hypoxia and determined that optical measurement of tumor vascular oxygen saturation is negatively correlated with tumor hypoxia. In chapter 3, we utilized this technique to study radiation-induced kinetics of tumor oxygenation among radiation-resistant and -sensitive tumors. We established tumor xenografts from two human head and neck cancer cell lines in mice which were treated with 4 doses of 2 Gy twice weekly for two weeks. We observed greater rate of reoxygenation in radiation-resistant tumors which was accompanied with greater content of hypoxia inducible factor-1α (HIF-1α). Our results indicate that reduced oxygen consumption rate can potentially play a significant role in promoting radiation resistance. In addition, the radiation-induced changes in tumor optical properties were used to train a logistic regression model which successfully differentiated local-control and treatment-failure tumors. In addition to changes in reoxygenation, radiation treatment has also been known to induce microenvironmental changes within tumor. Thus in chapter 4, we used Raman spectroscopy to investigate early radiation-induced biomolecular changes in tumor microenvironment of radiation-resistant and -sensitive tumors. Raman spectra of head and neck tumor xenografts 1, 24, and 48 hours after radiation was collected and the spectra were analyzed using multivariate curve resolution-alternating least squares (MCR-ALS) and pure spectral profiles of biological specimen were extracted. We observed higher contributions to Raman spectra from lipid- and collagen-like species respectively in radiation-sensitive and -resistant tumors. Our results indicate the sensitivity of Raman spectroscopy to radiation-induced microenvironmental changes at early time points after radiation. The association between the observed functional and biomolecular changes with the radiosensitivity of the utilized tumors motivate further clinical studies to investigate whether such changes can be used as potential biomarkers of radiation response

Effect of different levels of n-3 HUFA on larvae culture performances of Beluga (Huso huso) fish

The effects of n-3 highly unsaturated fatty acids (n-3 HUFA) were studied on Beluga (Huso huso) fish larvae by feeding fish larvae with live food enriched with 4 different oils (ICES 30/4, tuna eye oil, flaxseed oil and linseed oil) containing different levels of n-3 HUFA including 27.19, 20.33, 12.71 and 0.39 mg g^-1 dry weight of oil, respectively. Fish larvae weighing 30.00±2.00 mg were randomly divided into 12 groups of 150 fish each and triplicates fed the 4 experimental diets for 3 weeks. There were no differences in survival rates, but significant differences were found in growth rates and fatty acid composition of the fish larvae after 30 days. Fish fed low levels of dietary n-3 HUFA (0.39 mg g^-1 DW) showed poor n-3 HUFA contents but these fatty acids improved with the elevation of the n-3 HUFA levels in the diet up to 20 mg g^-1 DW. Fish fed the flaxseed oil showed the highest level of crude lipid 15.00±3.01). Results showed that tuna eye oil and ICES30/4-enriched live food (4.83 ±1.29 and 4.61 ±0.99 mg g^-1 DW, respectively) showed the highest n-3 HUFA content for sturgeon fish larvae

Essays on the Economics of Community College Students' Academic and Labor Market Success

Most students who enter a community college with the stated intention of attaining a credential or transferring to a four-year university leave without accomplishing either of those goals (National Center for Education Statistics, 2011). This dissertation attempts to contribute to the growing economic literature that seeks to understand the conditions and policies that can positively influence community college students' academic and labor market success. In the first essay, I examine the effectiveness of remediation for students who are identified to have the lowest skills in mathematics. Descriptively, while students assigned to remediation tend to have poor outcomes overall, students assigned to the lowest levels of remedial math have the worst outcomes of all students. I use data from the state of Virginia's 2004 cohort of students and use a regression discontinuity design and find that students assigned to the third lowest level of remedial math would have benefited if they had been able to skip that remedial course. In the second essay, I use administrative data to examine how working while taking classes affects community college students' academic outcomes. I use two different identification strategy: an individual fixed effects strategy that takes advantage of the quarterly nature of the data to control for unobserved and time-invariant differences among students, and an instrumental variable difference-in-differences (IV-DID) framework that takes advantage of the fact that there is an exogenous supply of retail jobs during the winter holidays. Using the IV-DID framework, I compare academic outcomes during the fall versus the winter quarter for students who are more likely to work in retail versus students who are less likely to work in retail, based on pre-enrollment association with retail jobs. I find small negative effects of working on GPA and possibly positive outcomes of working on credit accumulation. Finally, in the third essay, Madeline J. Weiss and I examine the returns to community college credentials using administrative data. Using an individual fixed effects identification strategy that compares trajectories of wages across individuals, we find positive and substantial wage returns to associate degrees and long-term certificates and no wage returns to short-term certificates, over and above wage increases for students who enrolled and earned some credits but never earned a credential or transferred. We also find that associate degrees tend to be awarded in low-returns fields, but that in almost any given field, the returns to associate degrees is higher than the returns to certificates

CLASS AND POLITICS IN POST-REVOLUTION IRAN: DESCRIPTIVE AND SUBSTANTIVE JUSTICE

Iranian society has undergone significant transformations since the 1962 Land Reform and the modernization plans implemented by its different governments. These transformations include industrialization, bureaucratization, population explosion, rural-urban migration, increase in the size of the working class, massive entry of women into the labor force, and the subsequent 1979 Islamic Revolution. Since the Revolution, the class structure and the composition of Iran’s political elites have changed significantly. Previous research has been particularly less attentive to the relationship between the structure of classes in Iran and the demographic composition of elected members of parliament (MPs). This study aims to enhance previous research by studying the nature and extent of representativeness of members of the Iranian parliament since the Revolution. Special attention will be paid to the descriptive representation of MPs by calculating the index of dissimilarity. Utilizing data on the occupational distribution of the general population and parliamentarians, this study will identify social class representativeness of MPs in each of the ten parliamentarian elections from 1980 to 2016. It employs a mixed methodology placing emphasis on the demographic (gender, age, ethnicity, etc.) and socioeconomic (education and occupation) dimensions of political representation. Using various theoretical models, it will test the extent to which each of the liberal-pluralist, instrumentalist and structuralist Marxists, or cultural reproduction theoretical approaches fit the evidence. The current study finds that educational credential, as a measure of credentialized cultural capital, is an important predictor of being elected as a member of parliament in Iran, supporting the cultural reproduction theory. Evidence also supports Marxist theory in that working class is underrepresented in the Majles, and that education itself is class-based. Finally, this study observes strong representation of professional and managerial class among the parliamentarians which lends support to liberal-pluralist theory

The Academic Consequences of Employment for Students Enrolled in Community College

College students are increasingly combining studying with paid employment, and community college students tend to work even longer hours compared with students at four-year colleges. Yet, there is little evidence on the academic consequences of community college students' term-time employment. Using a rare administrative dataset from Washington State that combines students' quarterly transcript records with earning records from the state Unemployment Insurance system, this study relies on two causal strategies: first, an individual fixed effects strategy that takes advantage of the quarterly nature of the data to control for unobserved and time-invariant differences among students, and second, an instrumental variable-difference-in-differences framework that takes advantage of the fact that there is an exogenous supply of retail jobs during the winter holidays. The study compares academic outcomes in the fall and winter quarters for students who were more likely to work in retail and those less likely to work in retail based on pre-enrollment association with retail jobs. The findings reject the possibility of large negative effects for small increases in employment for community college students

Moisture adsorption and spoilage characteristics of pea under adverse storage conditions

Field pea is the most produced and exported pulse crop in Canada, and makes a major contribution to Western Canadian agricultural diversification programs. Canada is now the world largest exporter of pea, lentil and chickpea and is fourth in dry bean. The demand for Canadian pulse products is steadily rising and the export market would continue to rise with the expected increased in production. Field pea exported to countries with tropical climates is at particular risk due to rapid loss of quality. It is therefore important to develop practical strategies for safe storage of feed pea. Knowledge on the moisture adsorption and spoilage characteristics of pea stored in adverse storage conditions is important in the transportation and storage of this export commodity. This study was initiated to examine the conditions that lead to quality losses in storage and transport of pea. Tropical and subtropical conditions were simulated in airtight chambers. Relative humidities (RH) of 60, 70, 80 and 90% were created by saturated salt solutions in airtight chambers at temperatures of 10, 20 and 30°C, while the same range of humidity was provided by dilute sulphuric acid in airtight chambers at 40°C in environmental cabinets. The four RH levels at each temperature for both whole and feed-grade pea were tested in duplicate. The samples were observed for changes in moisture content (MC), mold appearance and RH in specific time intervals. The amount of produced carbon dioxide (CO2) was measured in airtight chambers during storage to control the condition existing in sealed airtight chambers. Also, all components of feed-grade pea were exposed to RH of 90% and temperature of 40°C in separate airtight chambers to find the effect of each component on mold appearance. Molds were identified after appearance on the samples in order to pinpoint potential toxicity. Both feed and whole sound peas became molded after a short time of storage at high temperatures and high RH, but those stored at 70% and below did not develop mold after 175 days at 30 and 40°C (experiment duration) and 216 days at 10 and 20°C (experiment duration). Molds were identified mostly as species of Aspergillus and Penicillium. The amount of CO2 in the airtight chambers showed almost no difference from the ambient CO2 except at high temperature and high RH when samples had gone molded. Moisture adsorption equations were developed based on the moisture adsorption data in dynamic environment. Although the Page model showed to fit the data better, the exponential model was chosen to fit the data because its parameters can be better expressed as a function of temperature and RH of the storage environment. The mold-free days for both feed pea and clean pea were modeled at temperatures of 10, 20, 30 and 40°C and RH of 80 and 90%