A Study of Psychorophilic Bacteria in Frozen Foods

The bacteria examined in this study are facultative psychrohiles, which have their origin in the mesophilic group. Different members of the group have their optimum growth at temperatures slightly below the mesophilic range, but will grow at temperatures ranging from below zero to 25 degrees C. they have become increasingly important with the advent of the frozen food industry. Their presence in frozen foods is often the cause of objectionable flavor, putrid odor, or unnatural appearance. In this respect they are as important to the homemaker to the scientist and industrialist. It was with the hope of adding to the knowledge of this relatively little known group of microorganisms that this study was undertaken. The preservation of foods by freezing goes far back in history. Freezing foods was a common practice in northern Europe in ancient times. Meat and fish were allowed to freeze naturally in order to preserve them. Mechanical refrigeration did not appear until the nineteenth century. Meat packers were using natural ice refrigeration by 1860(12), but it was not until the ideal method. Birdseye and Fitzgerald (6) mention several man who pioneered in mechanical refrigeration devices. In 1861 Piper of Canden, Maine invented a process in which a mixture of salt and ice in metal pans was placed directly over fish which were held in the lower compartment of an insulated container. Davis, in 1869, received a patent for freezing fish in flat metal pans with telescoping metal covers, the fish being packed tightly in pans so there was contact on all sides. The pans were then surrounded with a freezing mixture of salt and ice. Hesketh and Marcet proposed in 1889 to freeze meat or other parishables by direct or indirect immersion in cold brine or other refrigerants. According to Jensen (12), G.H. Hammond in 1875 designed the first refrigerator car. This first car, crude but practical, subsequently enabled Swift to begin carrying dressed meats from Chicago to the east coast. The first frozen beef to be exported from the United States left New York City for England in 1875. (12) Preservation was accomplished by alternating layers of beef with layers of ice in the hold of the ship. The first method of cold storage used large blocks of ice as the cooling agent. These were placed in a room containing the food to be preserved. The ice cooled the air in the room sufficiently to prevent spoilage of the food. Gradually methods of mechanical refrigeration were developed. These were the compression system, the flooded system, and the absorption system. These systems use a variety of refrigerants, including amounts, carbon dioxide, sulfur dioxide, and methyl chloride. Each of the refrigerants is adaptable to some particular service. The compression system has the wildest use today. It enables the development of large warehouse near the production centers, where perishable foods can be stored before shipping to markets in other parts of the country. Cold storage, as we know it today, was developed about 1890, at the time when mechanical refrigeration first began to assume a practical importance in the food industry. A decade earlier, ammonia refrigeration machines were used to freeze fish. This same method was slowly expanded to include other foods as well. Eggs were first frozen in 1889. The freezing of fruits was begun in the eastern part of the United States about 1900. Freezing of berries in the Pacific Northwest was begun in 1910. The Birdseye organization started the commercial freezing of vegetables in Oregon in 1929 (30).The rapid freezing of foods has been known for a long time. Early scientists in the nineteenth century developed some theories as to the probable changes caused by freezing, but they never applied their work to practical processes of the industry. According to Tressler and Evers (30) in 1916, Plank Ehrenbaum and Reuter showed the practical advantages of the rapid freezing of meat. Since that time, rapid strides have been made both in the scientific and industrial fields. Today quick-freezing is considered one of the best methods of preserving many different types of food.There are three principle methods of quick-freezing: 1. Freezing by direct immersion in a refrigerating medium, such as low temperature brine; 2. Freezing by indirect contact with a refrigerant, by applying the product to a metal surface which is cooled by freezing brine; 3. Freezing in a blast of cold air. When water is frozen, it is changed to ice crystals. By the time the temperature has reached -3.9 degrees C most of the water is frozen and the ice crystals no longer increase in size. The temperature zone from -.6 C to -3.9 C was shown by Birdseye (4) to be the zone in which maximum growth of crystals occur. Crystals will be smaller if food is passed through this temperature zone quickly. The larger the crystals rupture the walls of the cells, changing the texture of the food and releasing nutrients which encourage bacterial growth

Computer Microvision for Microelectromechanical Systems

Contains table of contents for Section 3 and reports on five research projects.Charles S. Draper Laboratory Contract DL-H-496015Defense Advanced Research Project Agency Grant F30602-97-2-0106W.M. Keck Foundation Career Development ProfessorshipAlfred P. Sloan Foundation Instrumentation Gran

Self-love and sociability: the ‘rudiments of commerce’ in the state of nature

Istvan Hont’s classic work on the theoretical links between the seventeenth-century natural jurists Hugo Grotius and Samuel Pufendorf and the eighteenth-century Scottish political economists remains a popular trope among intellectual and economic historians of various stamps. Despite this, a common criticism levelled at Hont remains his relative lack of engagement with the relationship between religion and economics in the early modern period. This paper challenges this aspect of Hont’s narrative by drawing attention to an alternative, albeit complementary, assessment of the natural jurisprudential heritage of eighteenth-century British political economy. Specifically, the article attempts to map on to Hont’s thesis the Christian Stoic interpretation of Grotius and Pufendorf which has gained greater currency in recent years. In doing so, the paper argues that Grotius and Pufendorf’s contributions to the ‘unsocial sociability’ debate do not necessarily lead directly to the Scottish school of political economists, as is commonly assumed. Instead, it contends that a reconsideration of Grotius and Pufendorf as neo-Stoic theorists, particularly via scrutiny of their respective adaptations of the traditional Stoic theory of oikeiosis, steers us towards the heart of the early English ‘clerical’ Enlightenment

Large-Scale Gene-Centric Meta-Analysis across 39 Studies Identifies Type 2 Diabetes Loci

To identify genetic factors contributing to type 2 diabetes (T2D), we performed large-scale meta-analyses by using a custom similar to 50,000 SNP genotyping array (the ITMAT-Broad-CARe array) with similar to 2000 candidate genes in 39 multiethnic population-based studies, case-control studies, and clinical trials totaling 17,418 cases and 70,298 controls. First, meta-analysis of 25 studies comprising 14,073 cases and 57,489 controls of European descent confirmed eight established T2D loci at genome-wide significance. In silico follow-up analysis of putative association signals found in independent genome-wide association studies (including 8,130 cases and 38,987 controls) performed by the DIAGRAM consortium identified a T2D locus at genome-wide significance (GATAD2A/CILP2/PBX4; p = 5.7 x 10(-9)) and two loci exceeding study-wide significance (SREBF1, and TH/INS; p <2.4 x 10(-6)). Second, meta-analyses of 1,986 cases and 7,695 controls from eight African-American studies identified study-wide-significant (p = 2.4 x 10(-7)) variants in HMGA2 and replicated variants in TCF7L2 (p = 5.1 x 10(-15)). Third, conditional analysis revealed multiple known and novel independent signals within five T2D-associated genes in samples of European ancestry and within HMGA2 in African-American samples. Fourth, a multiethnic meta-analysis of all 39 studies identified T2D-associated variants in BCL2 (p = 2.1 x 10(-8)). Finally, a composite genetic score of SNPs from new and established T2D signals was significantly associated with increased risk of diabetes in African-American, Hispanic, and Asian populations. In summary, large-scale meta-analysis involving a dense gene-centric approach has uncovered additional loci and variants that contribute to T2D risk and suggests substantial overlap of T2D association signals across multiple ethnic groups

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

Elementary circuit properties of transistors

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