Evaluating the Accuracy of the 3-Sieve Particle Size Analysis Method Compared to the 12-Sieve Method

The 3-sieve particle size analysis method was developed to estimate the particle size of ground grain within feed mills without the time and expense required for a 12-sieve analysis. The 3-sieve method is more simplistic because it is hand-shaken and uses fewer sieves but has drawbacks because it is not as precise as the 12-sieve method. Because shaking is not automated, technician variation may impact results. Furthermore, the accuracy of the original 3-sieve method has been questioned because the method was developed for corn between 400 to 1,200 μm, and the industry now grinds various grains more finely. Some variations, such as changing the top sieve to a smaller diameter hole or using flow agent, may help improve its accuracy. In this instance, 420 grain samples were used to determine the impact of top sieve size, grain type, technician, and flow agent on the ability of a 3-sieve analytical method to accurately predict the mean particle size determined by a standardized 12-sieve method. The experiment was a 3 × 2 × 2 × 3 factorial with three technicians, two sieve sizes (U.S. No. 12 vs. 16 sieve as the top sieve), flow agent (0 vs. 0.5 g), and three grain types (corn, sorghum, or wheat). Prior to the experiment, all samples were analyzed according to the standard ASAE S319.4 method using a 12-sieve stack with a 15-min tap time and 1 g of flow agent. Linear regression was used to develop individual equations to predict the mean particle size for each of the 3-sieve methods compared to the standard 12-sieve method, and the GLIMMIX procedure of SAS was used to evaluate the impact main effects and interactions on prediction accuracy. All interactions were removed from the model due to insignificance (P \u3e 0.10). Technician, screen size, and flow agent did not affect the accuracy of the prediction equations. Grain was the only main effect of significance (P \u3c 0.05), where the prediction equation overestimated the particle size of wheat by approximately 15 μm and underestimated the particle size of corn by approximately 12 μm. While statistically significant, these variations were deemed to be sufficiently accurate for the 3-sieve method, and separate equations for each grain type were not warranted to retain the simplicity of the method. In summary, technician, sieve size, grain type, and the use of flow agent did not greatly affect the accuracy of the 3-sieve particle size analytical method, so the original method was concluded to be accurate and the preferred method

Evaluating the Effect of Manufacturing Porcine Epidemic Diarrhea Virus (PEDV)-Contaminated Feed on Subsequent Feed Mill Environmental Surface Contamination

This study aimed to utilize the only known pilot feed mill facility approved for pathogenic feed agent use in the United States to evaluate the effect of manufacturing Porcine Epidemic Diarrhea Virus (PEDV)-contaminated feed on subsequent feed mill environmental surface contamination. In this study, PEDV inoculated feed was manufactured and conveyed on equipment along with four subsequent batches of PEDV-free feed. Equipment and environmental surfaces were sampled using swabs and analyzed for the presence of PEDV RNA by PCR. The experiment was replicated three times with decontamination of the feed mill and all equipment between replications. Overall, environmental swabs indicated widespread surface contamination of the equipment and work area after a PEDV contaminated batch of feed was processed. There was little difference in environmental sample cycle threshold (Ct) values after manufacturing each of the subsequent PEDV-negative feed batches. In summary, introduction of PEDV-infected feed into a feed mill will likely result in widespread contamination of equipment and surfaces, even after several batches of PEDV-free feed are produced. Eliminating the PEDV RNA from the feed mill environment was challenging and required procedures that are not practical to apply on a regular basis in a feed mill. This data suggests that it is extremely important to prevent the introduction of PEDV-contaminated feed, ingredients, or other vectors of transmission to minimize PEDV-risk. More research should be conducted to determine if contaminated surfaces can lead to PEDV infectivity and to determine the best feed mill PEDV-decontamination strategies

Evaluating the effect of manufacturing porcine epidemic diarrhea virus (PEDV)-contaminated feed on subsequent feed mill environmental surface contamination

Citation: Schumacher, L. L., Cochrane, R. A., Evans, C. E., Kalivoda, J. R., Woodworth, J. C., Huss, A. R., . . . Tokach, M. D. (2016). Evaluating the effect of manufacturing porcine epidemic diarrhea virus (PEDV)-contaminated feed on subsequent feed mill environmental surface contamination. Journal of Animal Science, 94, 77-77. doi:10.2527/msasas2016-164With the introduction of porcine epidemic diarrhea virus (PEDV) to the United States in 2013 and the subsequent identification of feed as a route of transmission, identifying sources of feedstuff contamination and methods to reduce the risk of transmission at feed mills has become paramount. As with other biological hazards, contaminated ingredients can easily lead to cross-contamination of finished feeds and contamination throughout the facility. Therefore, the objective of this study was to monitor equipment and environmental contamination after manufacturing PEDV-positive feed and after the production of subsequent PEDV-negative feed. PEDV-positive feed (50 kg with 4.5 × 104 TCID50/g, Ct 11) was mixed in a 0.11m3 paddle mixer, discharged into a bucket elevator, and collected. Following processing of the contaminated feed, 4 subsequent batches of PEDV-free feed (sequence 1–4) were processed through the mixer and bucket elevator with no decontamination between batches to mimic commercial feed production. Porcine epidemic diarrhea virus contamination of equipment and surrounding areas were monitored via the collection of swabs that were analyzed via quantitative PCR (qPCR) for PEDV RNA. Swabs were collected from equipment and facility surfaces prior and after processing contaminated feed and after processing subsequent sequenced batch diets. Monitored areas for equipment included the interior of the mixer and bucket elevator. Facility areas included high and low foot traffic areas (concrete), floor drain (concrete), worker boot bottoms (rubber), table (metal), and door (metal). Three replications of contaminated feed and subsequent sequence batch diet processing was completed, with equipment and facility decontamination between replicates. Following qPCR analysis, Ct values ? 40 were considered PEDV-positive and all numerical data was converted to ± for statistical analysis via PROC MIXED procedure of SAS. The interactions feed contact surface by sequence were found to be significant (P < 0.01). All swabs collected from equipment surfaces after processing of PEDV-positive feed were positive for PEDV, while 16 of 18 of the collected facility swabs were positive for PEDV RNA. Following processing of the first sequence batch diet, 100% of equipment surfaces and 88.9% of facility surfaces were positive for PEDV. Surprisingly, a large percentage of equipment and facility surfaces remained PEDV-positive through the processing of the subsequent sequence batch diets. Furthermore, all swabs collected from concrete and rubber surfaces remained PEDV-positive through all processing of all diets. This study demonstrates the extent of equipment and facility contamination that could occur in a feed manufacturing facility after processing of PEDV-contaminated feed

Academic Morphing: Teaching Assistant to Faculty Member

This paper discusses the process by which graduate teaching assistants (TAs), participating in a longitudinal study, used their graduate TA experience to successfully survive the transition from being a teaching assistant to becoming a faculty member. A theoretical framework is presented that describes how individual characteristics of the TAs worked together with disciplinary, institutional, and departmental forces to shape a set of professional values. These professional values helped to form strategies for success: one set used for securing the first faculty position and the other set used to balance professional roles during the first year as a faculty member. These strategies for success contributed to the socialization process of the TAs in the first year of their faculty positions. The results of this study may help institutions broaden opportunities for graduate student support

ПІДВИЩЕННЯ НАУКОВОГО РІВНЯ ІНЖЕНЕРНОЇ ПІДГОТОВКИ ФАХІВЦІВ ЗАЛІЗНИЧНОГО ТРАНСПОРТУ

Purpose. Publication of the results of international scientific and technical cooperation of the Dnipropetrovsk National University of Railway Transport named after Academician V. Lazaryan (DNURT, Ukraine) and the Czech Technical University (CTU) in the field of engineering training of students on the basis of modern methods of development of scientific and creative abilities of students. Methodology. The development of scientific thought and the improvement of the professional level of students of engineering specialties of railway technical institutes may be carried out by different methods both during training and during extracurricular time. One of the methods for improving the scientific level of future engineers is the public lectures of renowned scholars and researchers from leading European higher education institutions, enabling students to have access to world-class advanced scientific idea. Findings. The authors have analyzed the activity of DNURT and CTU on scientific and educational preparation of students. It is emphasized that cooperation promotes strengthening of contacts between universities, improves the quality of students' training, is one of the factors of the professional development of future specialists, raising the scientific level of engineering training of railway transport professionals. It is proved that DNURT and CTU duly fulfill the higher education tasks of training of professional personnel who are able to work effectively in the global market, aimed at improving the quality and efficiency of education. Originality. This paper presents the analysis of results concerning the efficiency of application of modern methods for engineering training of students of technical higher educational institutions. It gives extended view of the main directions of international education activities. Practical value. It is confirmed that popularization of modern methods of propagation of engineering thought among student youth has acquired a new meaning and contributes to enhancing the scientific level of engineering training of railway transport professionals.Цель. Обнародование результатов международного научно-технического сотрудничества Днепропетровского национального университета железнодорожного транспорта имени академика В. Лазаряна (ДНУЖТ, Украина) и Чешского технического университета (ЧТУ, Чешская республика) в области инженерной подготовки студентов на базе современных методов развития научных и творческих способностей студентов. Методика. Развитие научной мысли и повышение профессионального уровня студентов машиностроительных специальностей технических вузов железнодорожного направления возможно осуществлять различными методами как во время обучения, так и факультативно, во внеучебное время. Одним из методов повышения уровня будущих инженеров есть публичные лекции известных ученых и исследователей из ведущих европейских высших учебных заведений, что дает возможность студентам иметь доступ к передовой научной мысли мирового уровня. Результаты. Приведен анализ деятельности ДНУЖТ и ЧТУ по научно-образовательной подготовке студентов. Подчеркнуто, что международное сотрудничество способствует укреплению контактов между университетами, повышает качество обучения студентов, является одним из факторов их профессионального становления, повышения уровня инженерной подготовки специалистов железнодорожного транспорта. Доказано, что ДНУЖТ и ЧТУ достойно выполняют поставленные высшим образованием задачи по подготовке профессиональных кадров, которые смогут эффективно работать в условиях глобального рынка, направленных на повышение качества, эффективности образования. Научная новизна. Выполнен анализ результатов эффективности применения современных методов инженерной подготовки студентов технических высших учебных заведений. Расширено представление об основных направлениях международной деятельности в области образования. Практическая значимость. Подтверждено, что популяризация современных методов, распространение инженерной мысли среди студенческой молодежи приобрело новое значение и способствует повышению научного уровня инженерной подготовки специалистов железнодорожного транспорта.Мета. Оприлюднення результатів міжнародного науково-технічного співробітництва Дніпропетровського національного університету залізничного транспорту імені академіка В. Лазаряна (ДНУЗТ, Україна) та Чеського технічного університету (ЧТУ, Чеська республіка) в галузі інженерної підготовки студентів на базі сучасних методів розвитку наукових та творчих здібностей студентів. Методика. Розвиток наукової думки та підвищення професійного рівня студентів машинобудівних спеціальностей технічних вищих навчальних закладів залізничного напрямку можливо здійснювати різними методами як під час навчання, так і факультативно, у позанавчальний час. Одним із методів підвищення наукового рівня майбутніх інженерів є публічні лекції відомих науковців та дослідників із провідних європейських вищих навчальних закладів, що дає можливість студентам мати доступ до передової наукової думки світового рівня. Результати. Наведено аналіз діяльності ДНУЗТ та ЧТУ з науково-освітньої підготовки студентів. Підкреслено, що міжнародна співпраця сприяє укріпленню контактів між університетами, поліпшує якість навчання студентів, є одним із чинників їх професійного становлення та підвищення наукового рівня інженерної підготовки фахівців залізничного транспорту. Доведено, що ДНУЗТ та ЧТУ гідно виконують поставлені вищою освітою завдання з підготовки професійних кадрів, які зуміють ефективно працювати в умовах глобального ринку, що спрямовані на підвищення якості, ефективності освіти. Наукова новизна. Виконано аналіз результатів ефективності застосування сучасних методів інженерної підготовки студентів технічних вищих навчальних закладів. Розширено уявлення про основні напрямки міжнародної діяльності в галузі освіти. Практична значимість. Підтверджено, що популяризація сучасних методів, поширення інженерної думки серед студентської молоді набуло нового значення та сприяє підвищенню наукового рівня інженерної підготовки фахівців залізничного транспорту

Diversity of Microbial Sialic Acid Metabolism

Sialic acids are structurally unique nine-carbon keto sugars occupying the interface between the host and commensal or pathogenic microorganisms. An important function of host sialic acid is to regulate innate immunity, and microbes have evolved various strategies for subverting this process by decorating their surfaces with sialylated oligosaccharides that mimic those of the host. These subversive strategies include a de novo synthetic pathway and at least two truncated pathways that depend on scavenging host-derived intermediates. A fourth strategy involves modification of sialidases so that instead of transferring sialic acid to water (hydrolysis), a second active site is created for binding alternative acceptors. Sialic acids also are excellent sources of carbon, nitrogen, energy, and precursors of cell wall biosynthesis. The catabolic strategies for exploiting host sialic acids as nutritional sources are as diverse as the biosynthetic mechanisms, including examples of horizontal gene transfer and multiple transport systems. Finally, as compounds coating the surfaces of virtually every vertebrate cell, sialic acids provide information about the host environment that, at least in Escherichia coli, is interpreted by the global regulator encoded by nanR. In addition to regulating the catabolism of sialic acids through the nan operon, NanR controls at least two other operons of unknown function and appears to participate in the regulation of type 1 fimbrial phase variation. Sialic acid is, therefore, a host molecule to be copied (molecular mimicry), eaten (nutrition), and interpreted (cell signaling) by diverse metabolic machinery in all major groups of mammalian pathogens and commensals

Three dimensional texture analysis of worked zirconium

22.00; Translated from Czech. (Kovove Mater. 1989 v. 27(2) p. 152-158)Available from British Library Document Supply Centre- DSC:9023.19(VR-Trans--4445)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

A Serratia marcescens OxyR Homolog Mediates Surface Attachment and Biofilm Formation▿

OxyR is a conserved bacterial transcription factor with a regulatory role in oxidative stress response. From a genetic screen for genes that modulate biofilm formation in the opportunistic pathogen Serratia marcescens, mutations in an oxyR homolog and predicted fimbria structural genes were identified. S. marcescens oxyR mutants were severely impaired in biofilm formation, in contrast to the hyperbiofilm phenotype exhibited by oxyR mutants of Escherichia coli and Burkholderia pseudomallei. Further analysis revealed that OxyR plays a role in the primary attachment of cells to a surface. Similar to what is observed in other bacterial species, S. marcescens OxyR is required for oxidative stress resistance. Mutations in oxyR and type I fimbrial genes resulted in severe defects in fimbria-associated phenotypes, revealing roles in cell-cell and cell-biotic surface interactions. Transmission electron microscopy revealed the absence of fimbria-like surface structures on an OxyR-deficient strain and an enhanced fimbrial phenotype in strains bearing oxyR on a multicopy plasmid. The hyperfimbriated phenotype conferred by the multicopy oxyR plasmid was absent in a type I fimbrial mutant background. Real-time reverse transcriptase PCR indicated an absence of transcripts from a fimbrial operon in an oxyR mutant that were present in the wild type and a complemented oxyR mutant strain. Lastly, chromosomal Plac-mediated expression of fimABCD was sufficient to restore wild-type levels of yeast agglutination and biofilm formation to an oxyR mutant. Together, these data support a model in which OxyR contributes to early stages of S. marcescens biofilm formation by influencing fimbrial gene expression