bluuebunny/crossref_metadata_2025 huggingface dataset:
Indicator Organisms in Meat and Poultry Slaughter Operations: Their Potential Use in Process Control and the Role of Emerging Technologies
Authors: SAINI PARMESH K. , MARKS HARRY M. , DREYFUSS MOSHE S. , EVANS PETER , COOK L. VICTOR , DESSAI UDAY
Published: August 2011

Measuring commonly occurring, nonpathogenic organisms on poultry products may be used for designing statistical process control systems that could result in reductions of pathogen levels. The extent of pathogen level reduction that could be obtained from actions resulting from monitoring these measurements over time depends upon the degree of understanding cause-effect relationships between processing variables, selected output variables, and pathogens. For such measurements to be effective for controlling or improving processing to some capability level within the statistical process control context, sufficiently frequent measurements would be needed to help identify processing deficiencies. Ultimately the correct balance of sampling and resources is determined by those characteristics of deficient processing that are important to identify. We recommend strategies that emphasize flexibility, depending upon sampling objectives. Coupling the measurement of levels of indicator organisms with practical emerging technologies and suitable on-site platforms that decrease the time between sample collections and interpreting results would enhance monitoring process control.
Emergence of Enterohemorrhagic Escherichia coli Serovar O157 Strains in Clade 8 with Highly Similar Pulsed-Field Gel Electrophoresis Patterns
Authors: YOKOYAMA EIJI , ETOH YOSHIKI , ICHIHARA SACHIKO , HORIKAWA KAZUMI , KONISHI NORIKO , KAI AKEMI , MATSUMOTO YUKO , KUROSAKI MORITO , KASAHARA HITOMI , KURAZONO TAKAYUKI , YODA KIYOE
Published: August 2011

Enterohemorrhagic Escherichia coli serovar O157 (O157) strains with highly similar pulsed-field gel electrophoresis (PFGE) patterns were isolated in Japan during 2007 and 2008. Several genetic features related to O157 evolution were investigated to indicate whether homoplasy might have contributed to the highly similar PFGE patterns in these strains. The O157 strains were classified in lineage I/II, as defined by a lineage-specific polymorphism assay-6 with an atypical allele in Z5935 (code: 231111). Analysis of the insertion sites of stx2 phage in these strains showed that the sites were “occupied” in yehV and “intact” in wrbA, indicating that the strains were derived from “Cluster 1” of “Subgroup C.” When a specific single-nucleotide polymorphism in ECs2357 in clade 8 strains was investigated, all of the strains in the present study were confirmed to be clade 8 strains. These results indicated that the O157 strains in this study had common genetic features, suggesting that the highly similar PFGE patterns of these strains were not due to homoplasy. Because no common source of these strains could be identified in 2007 to 2008 in Japan, these strains may have emerged from a unique O157 clade 8 clone and then spread by dissemination in Japan.
A Predictive Model for the Inactivation of Listeria innocua in Cooked Poultry Products during Postpackage Pasteurization
Authors: LI MIN , PRADHAN ABANI , COONEY LISA , MAUROMOUSTAKOS ANDY , CRANDALL PHILIP , SLAVIK MICHAEL , LI YANBIN
Published: August 2011

Contamination of Listeria monocytogenes in ready-to-eat poultry products poses potential risk of listeriosis to the public. To control the level of Listeria contamination, attention has been focused on the postpackage pasteurization of fully cooked poultry products. In this study, we sought to develop a model to predict the thermal inactivation of L. monocytogenes in chicken drumettes during postpackage hot water pasteurization. Fully cooked chicken drumettes were inoculated with Listeria innocua as a surrogate microorganism for Listeria monocytogenes, vacuum packaged, and treated in hot water baths at 60, 70, 80, and 90°C for different heating times. Experimental results showed that a 7-log CFU/g reduction of L. innocua occurred at 54, 28, 18, and 10 min at 60, 70, 80, and 90°C, respectively. The Weibull model was used to fit the survival curves of L. innocua at each heating temperature. The root mean square errors and residual plots indicated good agreements between the predicted and observed values. The predictive model was further validated by predicting a new data set generated in the pilot-plant tests. Model performance was evaluated by the acceptable prediction zone method, and the results indicated that the percentages of acceptable prediction errors were 100, 100, 82.4, and 87.5% at 60, 70, 80 and 90°C, respectively, which were all greater than the threshold acceptable value of 70%, indicating good performance of the model. The developed predictive model can be used as a tool to predict thermal inactivation behaviors of L. monocytogenes in ready-to-eat chicken drumettes products.
Differences in the Binding of Human Norovirus to and from Romaine Lettuce and Raspberries by Water and Electrolyzed Waters
Authors: TIAN PENG , YANG DAVID , MANDRELL ROBERT
Published: August 2011

Food contamination by human norovirus (hNoV) is a major cause of gastrointestinal disease. We evaluated the effectiveness of removing inoculated hNoV from the surfaces of raspberries and romaine lettuce by a simple wash in tap water and in different forms of electrolyzed water (EW), including acidic EW (AEW), neutral EW (NEW), and basic EW (BEW). A simple rinsing or soaking in water was able to remove >95% of hNoV from surface-inoculated raspberries. In contrast, only 75% of hNoV was removed from surface-inoculated romaine lettuce by rinsing in tap water. An AEW wash enhanced the binding of hNoV to raspberries and lettuce. Only 7.5% (±10%) and 4% (±3.1%) of hNoV were removed by AEW wash from surface-inoculated raspberries and lettuce, respectively. When raspberries and lettuce were prewashed with NEW or BEW prior to surface inoculation, an AEW wash likewise resulted in significantly less removal of hNoV compared with untreated samples. A prewash with AEW significantly decreased the removal of hNoV from raspberries and lettuce when they were washed with NEW, from 90.6 to 51% and from 76 to 51.3%, respectively. There are minimal or no improvements gained by use of any of the EWs instead of a regular tap water wash in removal of hNoV from produce. However, use of AEW shows a significant decrease in the removal of hNoV from contaminated produce compared with other water rinses. The ability to remove hNoV from different types of produce varies, possibly due to differences among types of ligand-like molecules that bind hNoV. The distribution of hNoV on raspberries and lettuce was studied using recombinant Norwalk-like particles (rNVLP). By immunofluorescence microscopy, we were able to observe binding of rNVLP only to vein areas of romaine lettuce, suggesting that the virus was binding to specific molecules in these areas. Random binding of rNVLP occurred only with raspberries prewashed with AEW or washed with AEW.
Characterization of Staphylococcus aureus Strains Isolated from Raw Milk Utilized in Small-Scale Artisan Cheese Production
Authors: D'AMICO DENNIS J. , DONNELLY CATHERINE W.
Published: August 2011

Staphylococcus aureus is an important agent of bacterial mastitis in milking animals and of foodborne intoxication in humans. The purpose of this study was to examine the genetic and phenotypic diversity, enterotoxigenicity, and antimicrobial resistance of S. aureus strains isolated from raw milk used for the production of artisan cheese in Vermont. Cross-tabulations revealed that the 16 ribotypes identified among the 90 milk isolates examined were typically associated with a specific animal species and that more than half of these ribotypes were unique to individual farms. In general, specific EcoRI ribotypes were commonly associated with specific phenotypical characteristics, including staphylococcal enterotoxin production or the lack thereof. Limited antimicrobial resistance was observed among the isolates, with resistance to ampicillin (12.51%) or penicillin (17.04%) most common. Two isolates of the same ribotype obtained from the same farm were resistant to oxacillin with 2% NaCl. More than half (52.22%) of isolates produced toxin, and 31 of the 32 isolates solely produced staphylococcal enterotoxin type C. Although these data demonstrate that S. aureus strains found in raw milk intended for artisan cheese manufacture are capable of enterotoxin production, staphylococcal enterotoxin C is not typically linked to foodborne illness. Because S. aureus is a common contaminant of cheese, an understanding of the ecology of this pathogen and of the antimicrobial susceptibility and toxigenicity of various strains will ultimately contribute to the development of control practices needed to enhance the safety of artisan and farmstead cheese production.
Quantitative Risk Assessment of Listeriosis Due to Consumption of Raw Milk†
Authors: LATORRE ALEJANDRA A. , PRADHAN ABANI K. , VAN KESSEL JO ANN S. , KARNS JEFFREY S. , BOOR KATHRYN J. , RICE DANIEL H. , MANGIONE KURT J. , GRÖHN YRJO T. , SCHUKKEN YNTE H.
Published: August 2011

The objectives of this study were to estimate the risk of illness for raw milk consumers due to Listeria monocytogenes in raw milk sold by permitted dealers, and the risk for people on farms who consume raw milk. Three scenarios were evaluated for raw milk sold by dealers: raw milk purchased directly from bulk tanks, from on-farm stores, and from retail. To assess the effect of mandatory testing of raw milk by regulatory agencies, the number of listeriosis cases per year was compared where no raw milk testing was done, only a screening test to issue a permit was conducted, and routine testing was conducted and milk was recalled if it was L. monocytogenes positive. The median number of listeriosis cases associated with consumption of raw milk from bulk tanks, farm stores, and retail for an intermediate-age population was 6.6 × 10−7, 3.8 × 10−5, and 5.1 × 10−5 cases per year, respectively. In populations with high susceptibility, the estimated median number of cases per year was 2.7 × 10−7 (perinatal, i.e., pregnant women and their fetuses or newborns) and 1.4 × 10−6 (elderly) for milk purchased from bulk tanks, 1.5 × 10−5 (perinatal) and 7.8 × 10−5 (elderly) for milk from farm stores, and 2.1 × 10−5 (perinatal) and 1.0 × 10−4 (elderly) for milk from retail. For raw milk consumed on farms, the median number of listeriosis cases was 1.4 × 10−7 cases per year. A greater risk of listeriosis was associated with consumption of raw milk obtained from retail and farm stores as compared with milk obtained from bulk tanks. This was likely due to additional time–temperature combination steps in the retail and farm store models, which increased the chances for growth of L. monocytogenes in raw milk. A close relationship between prevalence of L. monocytogenes in raw milk and the values of disease incidence was observed. Hence, a reduction in the number of cases per year in all populations was observed when a raw milk–testing program was in place, especially when routine testing and recalling of milk was conducted.
Surface Roughness of Stainless Steel Influences Attachment and Detachment of Escherichia coli O157
Authors: GOULTER-THORSEN REBECCA M. , TARAN ELENA , GENTLE IAN R. , GOBIUS KARI S. , DYKES GARY A.
Published: August 2011

Determining the influence of surface roughness on Escherichia coli O157 attachment to and detachment from stainless steel (SS) is important for controlling this foodborne pathogen. The aim of this study was to evaluate the interactions of six E. coli strains (four O157:H7, one O157:H12, and one O1:H7) with SS type 304 finishes of various surface roughness: 2B (unpolished surface), 4 (common food grade SS), and 8 (polished smooth surface). In attachment assays (exposure to cell suspensions with periodic swirling), bacteria were enumerated by epifluorescence microscopy, and in detachment assays a blotting technique and atomic force microscopy (AFM) were used. Attachment data suggest that E. coli attach in greater numbers to significantly smoother SS8; however, detachment assays and AFM data suggest cells are more easily removed from this finish. Conversely, attachment to SS2B was lower, and AFM data suggest that E. coli O157 may adhere more strongly to this finish. Attachment and detachment data for SS4 was variable, suggesting complex attachment mechanisms to this type of SS. SS4 is the most common material used in food processing facilities. The data from this study indicate that bacterial interactions with SS4 are complex and less easily predicted than those with SS of other finishes, including 2B and 8. These differences in bacterial attachment may be of concern to the food industry and warrant further investigation.
Identification of Bacteriocin Genes in Enterococci Isolated from Game Animals and Saltwater Fish
Authors: ALMEIDA TEREZA , BRANDÃO ANDREIA , MUÑOZ-ATIENZA ESTEFANÍA , GONÇALVES ALEXANDRE , TORRES CARMEN , IGREJAS GILBERTO , HERNÁNDEZ PABLO E. , HERRANZ CARMEN , CINTAS LUIS M. , POETA PATRÍCIA
Published: August 2011

Bacteriocins produced by enterococci, referred to as enterocins, possess great interest for their potential use as biopreservatives in food and feed, as well as alternative antimicrobials in humans and animals. In this context, the aim of the present study was to determine the antimicrobial activity and the presence of bacteriocin structural genes in fecal enterococcal isolates from animal origins. Evaluation of the direct antimicrobial activity of 253 isolates from wild boars (Sus scrofa, n = 69), mullets (Liza ramada, n = 117), and partridges (Perdix perdix, n = 67) against eight indicator bacterial strains (including Listeria monocytogenes, Pediococcus pentosaceus, and Enterococcus spp.) showed that 177 (70%) exerted antimicrobial activity against at least one indicator microorganism. From these isolates, 123 were further selected on the basis of their inhibition group, and 81 were found to be producers of bacteriocins active against Listeria monocytogenes. Analysis of the presence of enterocin structural genes in a subset of 36 isolates showed that 70% harbored one or more of the evaluated genes, those of enterocin P and hiracin JM79 being the most prevalent. These results show that wild animals constitute an appropriate source for the isolation of bacteriocinogenic enterococci.
Recovery of Alicyclobacillus from Inhibitory Fruit Juice Concentrates
Authors: MCNAMARA CHRISTOPHER J. , WIEBE DEBORAH , GOMEZ MARGARITA
Published: August 2011

Growth of Alicyclobacillus in low-pH fruit juices may result in off-odors and off-flavors due to the production of compounds such as guaiacol (2-methoxy phenol). An important step in preventing Alicyclobacillus contamination of fruit juices is the screening of incoming ingredients. Many fruit juice concentrates contain compounds that inhibit Alicyclobacillus growth, but beverages produced from the concentrates may not contain sufficient amounts of the active component to prevent spoilage. Therefore, accurate screening of juice concentrates is essential to prevent false-negative test results and product spoilage. The objective of this study was to evaluate isolation methods for detection of Alicyclobacillus in inhibitory juice concentrates. Recovery of Alicyclobacillus spores from inoculated and naturally contaminated concentrates was compared by using pour plate, spread plate, and filtration methods. Pour plates consistently recovered the lowest number of spores from inoculated concentrates. Spread plating was the most effective method used to recover spores from inoculated apple and pomegranate juice concentrates, while filtration resulted in the highest recovery from cranberry concentrate. When tested on naturally contaminated concentrates, the pour plate method failed to detect Alicyclobacillus in many samples. Filtration was much more effective. The filtration method increased the likelihood of detecting Alicyclobacillus contamination of fruit juice concentrates containing inhibitory compounds.
Detection of Banned Ruminant-Derived Material in Industrial Feedstuffs by TaqMan Real-Time PCR Assay
Authors: PEGELS NICOLETTE , GONZÁLEZ ISABEL , GARCÍA TERESA , MARTÍN ROSARIO
Published: August 2011

A ruminant-specific real-time PCR system was designed and applied for the detection of processed animal protein from ruminants in industrial feedstuffs. The assay includes a primer pair and a TaqMan probe selectively targeting mitochondrial 16S rRNA gene sequences from the ruminant group and another primer-probe set based on the eukaryotic nuclear 18S rRNA gene (positive amplification control). Both ruminant and eukaryotic PCR systems generated short PCR amplicons of 79 and 77 bp, respectively. To evaluate the suitability of the real-time PCR assay for the detection of banned by-products of ruminant origin, 126 feed samples subjected to rendering under current European legislation regulations were analyzed. The assay achieved 100% success in classifying the samples as positive or negative in terms of qualitative ruminant composition, with a detection limit of 0.1%. The quantitative ability of the assay is however restricted by variations in the composition and treatment of the feeds, which affect the amount and quality of amplifiable DNA.
Multistate Outbreak of Multidrug-Resistant Salmonella Newport Infections Associated with Ground Beef, October to December 2007
Authors: SCHNEIDER J. L. , WHITE P. L. , WEISS J. , NORTON D. , LIDGARD J. , GOULD L. H. , YEE B. , VUGIA D. J. , MOHLE-BOETANI J.
Published: August 2011

In late October 2007, an outbreak of multidrug-resistant Salmonella Newport infections affected 42 case patients in California, Arizona, Idaho, and Nevada. A case-control study implicated ground beef from one chain store. Despite detailed ground beef purchase histories—including shopper card information for several case patients—traceback efforts by both the U.S. Department of Agriculture, Food Safety and Inspection Service and the California Department of Public Health were unable to identify the source of contamination. Case patients consumed multiple types of ground beef products purchased at numerous chain store A retail locations. These stores had received beef products for grinding from multiple beef slaughter–processing establishments. Detailed retail grinding logs and grinding policies that prevent cross-contamination between batches of ground beef products are crucial in the identification of contaminated beef products associated with foodborne illness.
A formação do profissional da informação relacionada às tecnologias de informação: os bibliotecários na perspectiva da literatura, reflexões
Authors: Walter Maria Tereza Machado Teles
Published: August 2011

A maciça introdução das tecnologias de informação e de comunicação no contexto de trabalho dos profissionais da informação redundou em modificações na forma de atuar, nas perspectivas de fornecimento de informações e geração de produtos e serviços para os usuários e nas necessidades de formação e educação. Esse trabalho aborda alguns pontos relativos às dificuldades do equacionamento das disciplinas de conteúdo tecnológico no processo de formação dos bibliotecários e como essas questões têm sido observadas na literatura. Discute-se, também, as zonas de interface com outros segmentos profissionais e quanto se deve garantir de características distintivas de forma a manter a competitividade profissional dos bibliotecários no mercado de trabalho.
Revista Encontros Bibli como veículo de disseminação do conhecimento no Brasil
Authors: Silva Edna Lucia da , Pinheiro Liliane Vieira , Menezes Estera Muszkat
Published: August 2011

Pesquisa que apresenta subsídios para melhor compreensão da produção do conhecimento em Ciência da Informação, no Brasil, através da análise de parte desta produção difundida na Encontros Bibli: Revista Eletrônica de Biblioteconomia e Ciência da Informação. A investigação parte do pressuposto de que a produção científica reflete-se nas revistas publicadas e, por isso, verificou as características desta revista eletrônica como canal de difusão do conhecimento produzido em Ciência da Informação e Biblioteconomia no país. O estudo teve como limites de investigação a revista, os autores e os artigos, sua estrutura, sua evolução e desenvolvimento como veículo de produção do conhecimento das áreas de Ciência da Informação e Biblioteconomia.
Uso de ontologias para a extração de informações em atos jurídicos em uma instituição pública
Authors: Batres Eduardo Jaime Quirós , Oliveira Alcione de Paiva , Gabrielli Bruno Ventorim , Amorim Vinci Pegoretti , Moreira Alexandra
Published: August 2011

Com a expansão da Internet e a disponibilidade das informações em geral, surge um crescente anseio por parte de cidadãos e organizações de terem à sua disposição não só informações que dizem respeito a terceiros, mas também as informações a seu respeito ou que diretamente os afetem. Dentro deste contexto incluem-se as normas em geral e mais especificamente os atos emanados do serviço público. Este trabalho apresenta uma ferramenta automatizada, utilizando técnicas de extração automática de informações, com o intuito de extrair as principais informações contidas nos atos administrativos da Universidade Federal de Viçosa (UFV), visando a facilitar a utilização ampla dessas informações que, por serem de natureza pública, expandem seu interesse além das fronteiras do órgão emissor. Para isto se fez necessária a extração e estruturação das informações contidas nos mais diversos documentos eletrônicos dispersos pelos órgãos emissores. A ferramenta faz uso de uma ontologia construída especificamente para este propósito, possibilitando a geração de uma base de conhecimento cujo conteúdo reflete os campos obrigatórios e necessários para caracterizar um ato administrativo.
The recreation therapist versus the certified activity director: Which professional receives fewer deficiencies in long-term care facilities?
Authors: Legg, PhD, CNHA, GNP-BC, FACHCA Timothy J. , Nazarchuk, PhD, MHA, RN Sharon A. , Adelman, PhD, RN, CNS Deborah
Published: August 2011

The literature reports no studies that sought to determine which professional group (certified therapeutic recreation therapist versus certified activity director) achieves fewer survey deficiencies in the skilled nursing facility. This article will examine the scant and dated literature that is available to demonstrate which of these activity professionals has superior outcomes specific to the OBRA ’87 requirements. The article concludes with an articulation of the need for the discipline of recreation therapy to involve itself in outcomes research specific to which of the two disciplines better achieves the objectives of OBRA ’87.
Theory of human flourishing for therapeutic recreation
Authors: Wise, PhD, CTRS James B.
Published: August 2011

The purpose of this article is to present an overview of a theory of human flourishing and to outline how the theory can guide therapeutic recreation specialists as they strive to improve the lives of people with disabilities and illnesses. According to the theory, a flourishing life is marked by excelling in one or more leisure practices, authoring a coherent personal narrative, formulating and pursuing a meaningful telos, negotiating traditions, and acting virtuously. These constituent elements are described and then quad rugby is used to illustrate how a particular leisure practice contributes to flourish through its effects on each element. The article concludes with tasks that therapeutic recreation specialists should undertake to promote flourishing in people with disabilities and illnesses.
Methane flux, vertical gradient and mixing ratio measurements in a tropical forest
Authors: Querino C. A. S. , Smeets C. J. P. P. , Vigano I. , Holzinger R. , Moura V. , Gatti L. V. , Martinewski A. , Manzi A. O. , de Araújo A. C. , Röckmann T.
Published: August 2011

Abstract. Measurements of CH4 mixing ratio, vertical gradients and turbulent fluxes were carried out in a tropical forest (Reserva Biológica Cuieiras), about 60 km north of Manaus, Brazil. The methane mixing ratio and flux measurements were performed at a height of 53 m (canopy height 35 m). In addition, vertical CH4 gradients were measured within the canopy using custom made air samplers at levels of 2, 16 and 36 m above ground. The methane gradients within the canopy reveal that there is a continuous methane source at the surface. No clear evidence for aerobic methane emission from the canopy was found. The methane fluxes above the canopy are small but consistently upwards with a maximum early in the morning. The measured fluxes are in agreement with the observed CH4 gradient in the canopy. In the morning hours, a strong canopy venting peak is observed for both CH4 and CO2, but for CO2 this peak is then superimposed by photosynthetic uptake, whereas the peak lasts longer for CH4. Monthly averaged diurnal cycles of the CH4 mixing ratio show a decrease during daytime and increase during nighttime. The magnitude of the difference in CH4 mixing ratio between day and night gradually increases throughout the wet season. The fluxes required to explain the nighttime increase are in agreement with the nighttime fluxes measured above the canopy, which implies that the CH4 increase in the nighttime boundary layer originates from local sources.
Stratospheric ozone chemistry in the Antarctic: what controls the lowest values that can be reached and their recovery?
Authors: Grooß J.-U. , Brautzsch K. , Pommrich R. , Solomon S. , Müller R.
Published: August 2011

Abstract. Balloon-borne observations of ozone from Antarctic stations have been reported to reach ozone mixing ratios as low as about 10 ppbv at the 70 hPa level by late September. After reaching a minimum, ozone mixing ratios then increase to the ppmv level by late December. While the basic mechanisms causing the ozone hole have been known for more than 20 yr, the detailed chemical processes controlling how low the local concentration can fall, and how it recovers from the minimum have not been explored so far. Both of these aspects are investigated here by analysing results from the Chemical Lagrangian Model of the Stratosphere (CLaMS). We discuss the processes responsible for stopping of the catalytic ozone depletion. We show that an irreversible chlorine deactivation into HCl can occur either when ozone drops to very low values or by temperatures increasing above the PSC threshold in these simulations. As a consequence, the timing and mixing ratio of the minimum depends sensitively on model parameters including the ozone initialisation. The subsequent observed ozone increase between October and December is linked not only to transport, but also to photochemical ozone production, caused by oxygen photolysis and by the oxidation of carbon monoxide and methane.
Down the Rabbit Hole: toward appropriate discussion of methane release from gas hydrate systems during the Paleocene-Eocene thermal maximum and other past hyperthermal events
Authors: Dickens G. R.
Published: August 2011

Abstract. Enormous amounts of 13C-depleted carbon rapidly entered the exogenic carbon cycle during the onset of the Paleocene-Eocene thermal maximum (PETM), as attested to by a prominent negative carbon isotope (δ13C) excursion and deep-sea carbonate dissolution. A widely cited explanation for this carbon input has been thermal dissociation of gas hydrate on continental slopes, followed by release of CH4 from the seafloor and its subsequent oxidation to CO2 in the ocean or atmosphere. Increasingly, papers have argued against this mechanism, but without fully considering existing ideas and available data. Moreover, other explanations have been presented as plausible alternatives, even though they conflict with geological observations, they raise major conceptual problems, or both. Methane release from gas hydrates remains a congruous explanation for the δ13C excursion across the PETM, although it requires an unconventional framework for global carbon and sulfur cycling, and it lacks proof. These issues are addressed here in the hope that they will prompt appropriate discussions regarding the extraordinary carbon injection at the start of the PETM and during other events in Earth's history.
Gestión del conocimiento en la UNAH
Authors: Calderón Rutilia
Published: August 2011

CIENCIA Y TECNOLOGÍA (CT) entrevista a la Doctora Rutilia Calderón, hondureña, Catedrática en la Facultad de Ciencias Médicas de la UNAH. Actualmente se desempeña como Vicerrectora Académica de la UNAH. Es Coordinadora General del Instituto de Profesionalización y Superación Docente, de la UNAH. Es Asesora Internacional de OPS / OMS para Venezuela y Antillas Holandesas y Coordinadora del Programa de Comunicación Social de la OPS/OMS en Venezuela y Antillas Holandesas. DOI: http://dx.doi.org/10.5377/rct.v0i5.517 Revista Ciencia y Tecnología, No. 5, Segunda época, Diciembre 2009: 25-34
Una Especie de viuda negra (Latrodectus hesperus Chamberlain & Ivie) encontrada en Olancho, Honduras
Authors: Oviedo Alba Hernández , Marín Mirna , Martínez Oscar , Martínez Héctor Martínez
Published: August 2011

Se reporta el hallazgo de un ejemplar de viuda negra (Arachnidae, Theridiidae) colectada en San Esteban Olancho el 28 de Junio del 2009 entre cortezas de roble (Quercus sp.) en descomposición. La viuda negra colectada fue identificadas como Lactrodectus hesperus Chamberlain & Ivie, y de acuerdo a la bibliografía consultada, Lactrodectus hesperus es una especie que se reporta por primera vez en Honduras y en la región Centroamérica. Un comportamiento muy peculiar de la viuda negra, que le ha dado su nombre, es que puede ocasionalmente comerse el macho después de aparearse; este comportamiento puede tener una explicación biológica ya que para producir los huevos y tejer el saco, necesita extra proteínas y otros nutrientes. El veneno de la viuda negra es aproximadamente quince veces más neurotóxico que el de la serpiente cascabel. Sin embargo, cuando muerde inyecta una cantidad muy pequeña, por lo que no causa la muerte de la víctima. Palabras clave: Viuda negra; Arañas; Archnidos; Theridiidae; Lactrodectus; Honduras; veneno neurotóxico; mordeduras de arañas. DOI: http://dx.doi.org/10.5377/rct.v0i5.518 Revista Ciencia y Tecnología, No. 5, Segunda época, Diciembre 2009: 37-46
La tortura: punto de vista de los derechos humanos, punto de vista del derecho internacional humanitario
Authors: Ortega Reina Isabel Savoff
Published: August 2011

En la búsqueda de definir la tortura en el Derecho Internacional Humanitario, he escogido la definición contenida en la Convención contra la Tortura y Otros Tratos o Penas Crueles, Inhumanos o Degradantes, misma que establece : "Artículo 1.1 A los efectos de la presente Convención, se entenderá por el término "tortura" todo acto por el cual se inflija intencionadamente a una persona, dolores o sufrimientos graves, ya sean físicos o mentales, con el fin de obtener de ella o de un tercero, información o una confesión, de castigarla por un acto que haya cometido, o se sospeche que ha cometido, o de intimidar o coaccionar a esa persona o a otras, o por cualquier razón basada en cualquier tipo de discriminación, cuando dichos dolores o sufrimientos sean infligidos por un funcionario público u otra persona en el ejercicio de funciones públicas, a instigación suya, o con su consentimiento o aquiescencia. No se considerarán torturas los dolores o sufrimientos que sean consecuencia únicamente de sanciones legítimas, o que sean inherentes o incidentales a éstas".Por otro lado, el Derecho Internacional de los Derechos Humanos define los derechos humanos como los derechos que tienen todas las personas por la sola virtud de ser seres humanos, derivados de la inherente dignidad de la persona humana, y contenidos en la Declaración Universal de los Derechos Humanos y otros instrumentos legales internacionales.El derecho internacional humanitario es un conjunto de normas que, en tiempos de guerra, protege a las personas que no participan o han dejado de participar en las hostilidades, ya sean civiles, personal militar, religioso o médico, prisioneros de guerra, restringiendo incluso los métodos de guerra (como uso de cierto equipo bélico, tácticas, etc.). Los cuatro Convenios de Ginebra (1864, 1906, 1929, 1949) y los dos Protocolos de 1977 adicionales a estos, son los principales instrumentos legales de Derecho Internacional Humanitario. Palabras claves: Tortura; funcionarios del Estado; Derecho Internacional de los Derechos Humanos; Derecho Internacional Humanitario. DOI: http://dx.doi.org/10.5377/rct.v0i6.512 Revista Ciencia y Tecnología, No. 6, Segunda época, junio 2010: 55-79
El desempleo y subempleo juvenil asociado a la baja calificación técnica de los jóvenes egresados de secundaria. Estudio de caso del Distrito Central período 1990-2006
Authors: Contreras Merlin Ivania Padilla
Published: August 2011

Este estudio tiene como objetivo general, evaluar las características del desempleo y subempleo juvenil en el Distrito Central y su relación con la situación actual de la educación técnica como medio para la inserción laboral de los jóvenes egresados de secundaria. Los objetivos específicos incluyen conocer la situación actual de la educación técnica y tecnológica de los jóvenes egresados de secundaria, la evaluación de la infraestructura físico/pedagógica de los centros de educación técnica y el nivel académico de los docentes, así como la evaluación de la magnitud y tendencias del desempleo juvenil en el Distrito Central. El objeto de estudio, el desempleo y subempleo juvenil, está relacionado con muchos factores que tienen que ver con causas estructurales propias del modelo de acumulación capitalista, tal es el caso de las enormes masas de desempleados y desalentados que hacen contrapeso en las condiciones de empleabilidad de los que están empleados. Por otro lado la calificación técnica influye definitivamente en la inserción y la permanencia en un empleo de calidad. El estudio logra establecer esta relación mediante el análisis de la formación profesional de nivel medio que reciben los jóvenes en un periodo de 3 quinquenios en donde las tendencias apuntan a una tercerización de la economía y de la formación misma, pero en condiciones de precariedad e inestabilidad laboral. Por otro lado esta calificación técnica tiene sus causas en el mismo sistema educativo y particularmente en el nivel de educación media que históricamente ha estado desarticulado del resto de los niveles educativos por ser considerado una etapa de transición entre el estudio y el trabajo. El estudio permite concluir que la mitad de los docentes de educación media no ostentan títulos formales para ejercer, lo cual impacta directamente sobre la calidad de enseñanza. Los colegios técnicos utilizados en la muestra de este estudio presentan características específicas de formación profesional; pero no cuentan con políticas institucionales de inserción laboral que facilite a los alumnos el acceso y permanencia en un centro de trabajo. Todos estos factores repercuten en la calidad de los puestos de trabajo que son ocupados por los jóvenes y dificulta su acumulación de experiencia laboral y otras destrezas que aseguren un mejor puesto de trabajo en el futuro. Palabras clave: desempleo juvenil; inserción laboral de jóvenes; calificación técnica; precarización laboral. DOI: http://dx.doi.org/10.5377/rct.v0i6.513 Revista Ciencia y Tecnología, No. 6, Segunda época, junio 2010: 80-96
Desapariciones forzadas: una violación al derecho internacional humanitario y derecho internacional de derechos humanos
Authors: Santos Ilda Lilian Cartagena
Published: August 2011

Se desarrolla un análisis sobre el derecho internacional de los derechos humanos y el derecho internacional humanitario, vinculando ambos al reflexionar sobre el problema de las desapariciones forzadas, ya que éste es un delito complejo, múltiple y acumulativo, que supone la violación de un conjunto diverso de derechos humanos y que cometido en determinadas circunstancias, conflictos armados internacionales como en conflictos internos, constituye también un crimen de lesa humanidad. Palabras clave: Desapariciones forzadas; Personas; Conflictos armados; Violencia interna; Privación arbitraria de la libertad; Violación de derechos humanos; Derecho Internacional Humanitario; Derecho Internacional de Derechos Humanos. DOI: http://dx.doi.org/10.5377/rct.v0i6.515 Revista Ciencia y Tecnología, No. 6, Segunda época, junio 2010: 110-125
Ti‐Doping to Reduce Conductivity in Bi0.85Nd0.15FeO3 Ceramics
Authors: Kalantari Kambiz , Sterianou Iasmi , Karimi Sarah , Ferrarelli Matthew C. , Miao Shu , Sinclair Derek C. , Reaney Ian M.
Published: August 2011

In 2009, Karimi et al. reported that Bi1‐xNdxFeO3 0.15 ≤ x ≤ 0.25 exhibited a PbZrO3 (PZ)‐like structure. These authors presented some preliminary electrical data for the PZ‐like composition but noted that the conductivity was too high to obtain radio‐frequency measurements representative of the intrinsic properties. In this study, Bi0.85Nd0.15Fe1‐yTiyO3 (0 ≤ y ≤ 0.1) were investigated, in which Ti acted as a donor dopant on the B‐site. In contrast to the original study of Karimi et al., X‐ray diffraction (XRD) of Bi0.85Nd0.15FeO3 revealed peaks which were attributed to a mixture of PZ‐like and rhombohedral structures. However, as the Ti (0 < y ≤ 0.05) concentration increased, the rhombohedral peaks disappeared and all intensities were attributed to the PZ‐like phase. For y = 0.1, broad XRD peaks indicated a significant decrease in effective diffracting volume. Electron diffraction confirmed that the PZ‐like phase was dominant for y ≤ 0.05, but for y = 0.1, an incommensurate structure was present, consistent with the broadened XRD peaks. The substitution of Fe3+ by Ti4+ decreased the dielectric loss at room temperature from >0.3 to <0.04 for all doped compositions, with a minimum (0.015) observed for y = 0.03. The decrease in dielectric loss was accompanied by a decrease in the room temperature bulk conductivity from ∼1 mS cm−1 to <1 μS cm−1 and an increase in bulk activation energy from 0.29 to >1 eV. Plots of permittivity (ϵr) versus temperature for 0.01 ≤ y ≤ 0.05 revealed a step rather than a peak in ϵr on heating at the same temperature determined for the antiferroelectric–paraelectric phase transition by differential scanning calorimetry. Finally, large electric fields were applied to all doped samples which resulted in a linear dependence of polarisation on the electric field similar to that obtained for PbZrO3 ceramics under equivalent experimental conditions.
Oxygen Rich Titania: A Dopant Free, High Temperature Stable, and Visible‐Light Active Anatase Photocatalyst
Authors: Etacheri Vinodkumar , Seery Michael K. , Hinder Steven J. , Pillai Suresh C.
Published: August 2011

The simultaneous existence of visible light photocatalytic activity and high temperature anatase phase stability up to 900 °C in undoped TiO2 is reported for the first time. These properties are achieved by the in‐situ generation of oxygen through the thermal decomposition of peroxo‐titania complex (formed by the precursor modification with H2O2). Titania containing the highest amount of oxygen (16 H2O2‐TiO2) retains 100% anatase phase even at 900 °C, where as the control sample exists as 100% rutile at this temperature. The same composition exhibits a six‐fold and two‐fold increase in visible light photocatalytic activities in comparison to the control sample and the standard photocatalyst Degussa P‐25 respectively. Among the various para­meters affecting the photocatalytic action, such as band gap narrowing, textural properties, crystallite size, and anatase phase stability, band gap narrowing was identified as the major factor responsible for the visible light photocatalytic activity. Increased Ti–O–Ti bond strength and upward shifting of the valence band (VB) maximum, which is responsible for the high temperature stability and visible light activity respectively, are identified from FT–IR, XPS, and photoluminescence (PL) spectroscopic studies. It is therefore proposed that the oxygen excess defects present in these titania samples are responsible for the high temperature stability and enhanced visible light photocatalytic activities.
Optimized Colorimetric Photonic‐Crystal Humidity Sensor Fabricated Using Glancing Angle Deposition
Authors: Hawkeye Matthew M. , Brett Michael J.
Published: August 2011

Colorimetric sensing, where environmental changes are transduced into visual color changes, provides an intuitively simple yet powerful detection mechanism that is well‐suited to the realization of low‐cost and low‐power sensors. A new approach in colorimetric sensing exploits the structural colour of photonic crystals (PCs) to create new color‐changing materials, however much work is still required to simultaneously achieve optimized sensor response and low‐cost, scalable nanofabrication. This work responds to these challenges by designing, fabricating and evaluating a mesoporous PC sensor optimized to exhibit as large as possible color‐shift in response to small changes in relative humidity (RH). A novel design optimization is achieved by employing a colorimetric framework that translates simulated/measured spectral quantities into numeric color values directly related to color perception. The sensor design is then realized using a mesoporous TiO2 PC, fabricated using glancing angle deposition (GLAD). The GLAD technique is a bottom‐up, single‐step nanofabrication method providing the nanoscale precision required to successfully realize the optimized PC design. The PC sensor is shown to be highly sensitive and stable: the PC structural‐color changes visibly due to RH changes smaller than 1%, and the response is stable over hundreds of hours of sensor operation. Additionally, measurements and simulations are used to reveal the important link between the PC optical modes, pore geometry, and sensor response which will be useful in future PC sensor experiments. The combination of bottom‐up nanofabrication with visible color‐based sensing, coupled with the useful design methodology, will lead to further developments in low‐cost, widely deployable optical sensors.
Limited evidence of human papillomavirus on breast tissue using molecular in situ methods
Authors: Baltzell Kimberly , Buehring Gertrude C. , Krishnamurthy Savitri , Kuerer Henry , Shen Hua Min , Sison Jennette D.
Published: August 2011

BACKGROUND:

Human papillomavirus (HPV) has been proposed as an etiologic agent of breast cancer based on numerous reports of high‐risk (oncogenic) HPV types in malignant breast tissues. However, most of those studies used standard and nested solution polymerase chain reaction (PCR) techniques, both of which are disadvantaged by vulnerability to laboratory contamination from positive control DNA and the inability to localize the signal to a specific cell type. To overcome these drawbacks, the authors of this report explored the use of in situ molecular methods of viral detection to reassess the frequency of HPV in malignant breast tissue.

METHODS:

In situ hybridization (ISH) was used with probes that were specific for the capsid region of 12 oncogenic HPV types, and in situ PCR (IS‐PCR) was used with primers that were specific for the capsid region of HPV‐16, which is the most common oncogenic HPV type. These methods were resistant to molecular contamination and allowed identification of the positive cell type. The specimens examined were malignant tissues from patients with 70 breast cancer patients at The University of Texas M. D. Anderson Cancer Center in Houston, Texas.

RESULTS:

HPV was observed in 4 of 70 specimens (5.7%) using ISH and in 2 of 70 specimens (2.9%) of specimens using IS‐PCR. Concordance between the 2 methods was high for negative specimens; both methods yielded negative results in 66 of 70 specimens (94.3%). However, there was no concordance for the few positive specimens, probably because of differences in sensitivity and the targeted HPV types.

CONCLUSIONS:

Oncogenic (high‐risk) HPV types were present in malignant breast epithelium very infrequently and, thus, may be causative agents of only a relatively small proportion of all breast cancers. Cancer 2012;. © 2011 American Cancer Society.
Exposure to bisphosphonates and risk of colorectal cancer
Authors: Singh Harminder , Nugent Zoann , Demers Alain , Mahmud Salaheddin , Bernstein Charles
Published: August 2011

BACKGROUND:

Chemoprevention is a potentially attractive strategy for decreasing the burden of colorectal cancer (CRC). Preclinical studies suggest that bisphosphonates (BPs) may have direct antitumour effects against CRC. The objective of this study was to determine the effect of exposure to BPs on the incidence of CRC.

METHODS:

The Manitoba Cancer Registry was used to identify patients who were diagnosed with CRC from 2000 to 2009 who had been living in Manitoba for at least 5 years before diagnosis (cases). Each case was matched to 10 controls of similar age, sex, and duration of residence in Manitoba using incidence density sampling. Exposure to BPs was determined using the provincial Drug Program Information Network database. Conditional logistic regression analysis was performed to determine the effect of exposure to BPs on CRC incidence with adjustment for health care use, medical procedures (including lower gastrointestinal endoscopy), socioeconomic status, and pre‐existing health conditions.

RESULTS:

In total, 5425 patients with CRC were matched to 54,242 controls. In the multivariate analysis, exposure to BPs was associated with a reduction in the risk of CRC (2‐13 BP prescriptions over ≥5 years: odds ratio [OR] 0.84; 95% confidence interval [CI], 0.71‐1.00; ≥14 BP prescriptions over ≥5 years: OR, 0.78; 95% CI, 0.65‐0.94). When the effect of specific BP agents was evaluated, the effect was significant only for exposure to risedronic acid (OR, 0.50; 95% CI, 0.30‐0.85). There was no significant effect of increasing duration or cumulative dose of alendronic acid.

CONCLUSIONS:

The results from this study suggested that exposure to BPs, especially risedronic acid, may be associated with a decreased risk of developing CRC. Cancer 2012;. © 2011 American Cancer Society.
Validation of the royal marsden hospital prognostic score in patients treated in the phase I clinical trials program at the MD Anderson Cancer Center
Authors: Garrido‐Laguna Ignacio , Janku Filip , Vaklavas Christos , Falchook Gerald S. , Fu Siqing , Hong David S. , Naing Aung , Tsimberidou Apostolia M. , Wen Sijin , Kurzrock Razelle
Published: August 2011

BACKGROUND:

The authors validated the Royal Marsden Hospital (RMH) prognostic score in patients with advanced lung, pancreatic, and head and neck cancers who were enrolled on phase 1 trials in the MD Anderson Cancer Center Phase I Clinical Trials Program.

METHODS:

The RMH score uses albumin (≥3.5 g/dL vs <3.5 g/dL), lactate dehydrogenase (less than or equal to the upper limit of normal [≤ULN] vs >ULN), and the number of metastatic sites (≤2 sites vs ≥3 sites) to predict patient survival in phase 1 trials. The authors of this report retrospectively reviewed the outcomes of 229 consecutive patients with lung, pancreatic, and head and neck tumors who were treated on 57 phase 1 trials.

RESULTS:

Two hundred twenty‐nine consecutive patients with lung cancer (N = 85), pancreatic cancer (N = 83), and head and neck tumors (N = 61) were treated. The median patient age was 60 years (range, 26‐85 years), and 63% of the patients were men. Patients with a good RMH prognostic score (0‐1) at baseline had a longer median survival than patients with a poor prognostic score (2‐3; 33.9 weeks vs 21.1 weeks; P < .0001). The RMH score was an independent variable that predicted survival in multivariate analysis. Other independent variables that predicted better survival were hemoglobin level (≥10.5 g/dL), Eastern Cooperative Oncology Group performance status (0‐1), and tumor type. Patients who were treated on first‐in‐human trials did not fare worse compared with those who were not treated on first‐in‐human trials.

CONCLUSIONS:

For patients with lung, pancreatic, and head and neck tumors who were treated on phase 1 trials, survival was predicted accurately by the RMH prognostic score. Cancer 2012;. © 2011 American Cancer Society.