• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 18
  • 5
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 40
  • 19
  • 17
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Effectiveness and mechanisms of action of whitening dentifrices on enamel extrinsic stains

Alshara, Salem A. January 2012 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Whitening dentifrices use different mechanisms for stain removal and prevention. These approaches are abrasives, oxidizing agents, and chemical cleaning agents. The objectives of this in-vitro study were: 1) To compare the whitening effect of commercial whitening and non-whitening dentifrices; 2) To verify the mechanism of action of whitening dentifrices by contrasting two experimental models: chemical model (toothpaste exposure only) and chemo-mechanical (toothpaste exposure with tooth-brushing abrasion). The 256 bovine enamel specimens (10 mm x10 mm) were prepared and partially stained. They were assigned to 8 groups: 6 whitening dentifrices, 1 non-whitening reference dentifrice and deionized water (control); and they were further divided in 2 subgroups (n = 16), chemical and chemo-mechanical. Specimens were exposed to dentifrice slurries 2X/day for 1 min and brushed or not, according to each model. In between dentifrice treatments, specimens were exposed to the staining solution for 5 h. This protocol was repeated for 5 consecutive days and enamel color changes (∆E, ∆L) were measured by spectrophotometry after each day. The abrasivity of the toothpastes was determined using a standard test (ISO 11609). Significantly higher ∆E values (whitening effect) were observed for all groups (p < 0.05), except for the control, when tested in the chemo-mechanical model. In this model, the whitening ability of the toothpastes was mainly determined by their abrasive levels. For the chemical model, no significant differences were observed among groups (p > 0.05). Whitening dentifrices can be effective in preventing and removing enamel surface staining, when associated with tooth-brushing abrasion. This was modulated by the abrasive level of the tested toothpastes, with no chemical action attributed to the chemical agents. / indefinitely
32

Avaliação de corantes para a detecção da viabilidade do fitoplâncton marinho / Staining evaluation for detection of marine phytoplankton viability

Mattiello, Izadora De La Volpe 22 May 2014 (has links)
O fitoplâncton é sensível às perturbações ambientais e identificar a viabilidade destes organismos é importante para o monitoramento aquático. O termo viabilidade tem sido usado neste contexto para determinar basicamente se o organismo está vivo ou morto. O uso de corantes vitais e mortais tem sido uma das técnicas aplicadas neste tipo de análise, mas ainda não se conhece a potencialidade de alguns corantes que se apliquem a espécies de fitoplâncton. Neste trabalho, foram utilizadas espécies de diferentes grupos taxonômicos mantidas em cultivo, as quais foram submetidas a uma série de corantes vitais e mortais com o objetivo de detectar a viabilidade do fitoplâcton marinho. Dentre os corantes testados, o vermelho neutro, azul de Evans e o fluorescente CMFDA tiveram os melhores resultados (observado x esperado) em testes com diferentes porcentagens de células vivas e mortas. A combinação entre o corante vital vermelho neutro e o mortal azul de Evans não foi efetiva para análise simultânea. Alexandrium tamiyavanichii foi a espécie que teve menor afinidade com os corantes. Também foram comparados diferentes métodos de observação e registro de células coradas e não coradas, provando que é possível substituir a observação direta da microscopia pela filmagem no microscópio ou pela FlowCAM. A vantagem do uso destes métodos é que além de serem mais rápidos, é possível salvar as imagens capturadas e não é necessário fazer a análise instantaneamente. O método da filmagem é vantajoso, pois é fácil de ser desenvolvido em qualquer laboratório. / Phytoplankton cells are sensitive to environmental perturbations and, therefore, identifying their viability is important for aquatic monitoring. The term viability has been used in this context to determine whether an organism is alive or dead. The use of vital and mortal stains to detect phytoplankton viability is a promising approach. In this study we investigated the efficiency of several vital and mortal dyes in detecting marine phytoplankton viability. Best results were achieved with neutral red, Evans blue and the fluorescent stain in tests with different percentages of live and dead cells. The combination of neutral red and Evans blue (vital and a mortal stains, respectively) was not effective in simultaneous analysis. Alexandrium tamiyavanichii had low affinity for any given stain. Different observational methods were compared, suggesting that direct microscopic counts can be replaced by image acquisition methods using either a microscope-mounted camera or a FlowCAM. Such imaging methods are fast, allow image archiving, and image processing can be performed on a later stage, which is useful when several experiments need to be run in a short period of time.
33

Avaliação de corantes para a detecção da viabilidade do fitoplâncton marinho / Staining evaluation for detection of marine phytoplankton viability

Izadora De La Volpe Mattiello 22 May 2014 (has links)
O fitoplâncton é sensível às perturbações ambientais e identificar a viabilidade destes organismos é importante para o monitoramento aquático. O termo viabilidade tem sido usado neste contexto para determinar basicamente se o organismo está vivo ou morto. O uso de corantes vitais e mortais tem sido uma das técnicas aplicadas neste tipo de análise, mas ainda não se conhece a potencialidade de alguns corantes que se apliquem a espécies de fitoplâncton. Neste trabalho, foram utilizadas espécies de diferentes grupos taxonômicos mantidas em cultivo, as quais foram submetidas a uma série de corantes vitais e mortais com o objetivo de detectar a viabilidade do fitoplâcton marinho. Dentre os corantes testados, o vermelho neutro, azul de Evans e o fluorescente CMFDA tiveram os melhores resultados (observado x esperado) em testes com diferentes porcentagens de células vivas e mortas. A combinação entre o corante vital vermelho neutro e o mortal azul de Evans não foi efetiva para análise simultânea. Alexandrium tamiyavanichii foi a espécie que teve menor afinidade com os corantes. Também foram comparados diferentes métodos de observação e registro de células coradas e não coradas, provando que é possível substituir a observação direta da microscopia pela filmagem no microscópio ou pela FlowCAM. A vantagem do uso destes métodos é que além de serem mais rápidos, é possível salvar as imagens capturadas e não é necessário fazer a análise instantaneamente. O método da filmagem é vantajoso, pois é fácil de ser desenvolvido em qualquer laboratório. / Phytoplankton cells are sensitive to environmental perturbations and, therefore, identifying their viability is important for aquatic monitoring. The term viability has been used in this context to determine whether an organism is alive or dead. The use of vital and mortal stains to detect phytoplankton viability is a promising approach. In this study we investigated the efficiency of several vital and mortal dyes in detecting marine phytoplankton viability. Best results were achieved with neutral red, Evans blue and the fluorescent stain in tests with different percentages of live and dead cells. The combination of neutral red and Evans blue (vital and a mortal stains, respectively) was not effective in simultaneous analysis. Alexandrium tamiyavanichii had low affinity for any given stain. Different observational methods were compared, suggesting that direct microscopic counts can be replaced by image acquisition methods using either a microscope-mounted camera or a FlowCAM. Such imaging methods are fast, allow image archiving, and image processing can be performed on a later stage, which is useful when several experiments need to be run in a short period of time.
34

Avaliação microbiana das manchas dentárias extrínsecas negras em pacientes submetidos a tratamento ortodôntico / Bacterial analysis of black tooth stains in patients on orthodontic treatment

COSTA, Marília Teixeira 04 July 2011 (has links)
Made available in DSpace on 2014-07-29T15:25:15Z (GMT). No. of bitstreams: 1 tese mariliia teixeira costa - ciencias da saude.pdf: 592941 bytes, checksum: bbd7a80041fff15e5e5a8747d934ef5f (MD5) Previous issue date: 2011-07-04 / Black extrinsic tooth stains appear on the smooth surfaces of teeth, parallel to the marginal gum and are considered a specific form of biofilm due to the high content of calcium, phosphate and insoluble iron salt. This study evaluated the profile of bacterial biofilms in patients with black extrinsic tooth stain with or without fixed metal braces installed. Four bacteria were investigated using conventional multiplex PCR (Polymerase Chain Reaction), black-pigmented bacteria: Prevotella nigrescens and Prevotella intermedia and non pigmented bacteria: Streptococcus mutans and Actinomyces spp. The study enrolled 52 patients, 25 females and 27 males. They were divided into two groups: Group I: 26 patients with black extrinsic tooth stains and Group II: 26 without stains. Twenty patients had fixed orthodontic brackets of stainless steel. The results showed that in both group (I and II) 61.5% of patients had at least one of the bacteria investigated. The P. nigrescens was the most frequently bacteria detected [Group I (30.7%) and Group II (46.1%)], P. intermedia was detected in 3.8% in Group I and 11.5% in Group II. The non pigmented bacteria were found in similar rates in Groups I and II, 19.2% vs 11.5% for Actinomyces spp and 23.1% vs 30.7% for S. mutans. There were no statistically significant differences when comparing the frequencies of each bacterium between groups, indicating that bacterial profiles were similar between patients with or without black extrinsic stains. When analyzed the frequencies of bacteria in the biofilm in black extrinsic tooth stain in patients with braces results indicated that it did not alter the frequency of bacteria found, however, it was observed that the presence of fixed orthodontic appliance significantly reduces the associations between bacteria in the biofilm of black extrinsic stains (p <0.05). / As manchas dentárias extrínsecas negras aparecem nas superfícies lisas dos dentes, paralelas à gengiva marginal, e são consideradas uma forma de biofilme dentário devido ao grande conteúdo de cálcio, fosfato e sal insolúvel de ferro. Este estudo foi realizado com o objetivo de avaliar o perfil bacteriano dos biofilmes dentários de pacientes portadores ou não de manchas dentárias extrínsecas negras, com ou sem aparelho ortodôntico metálico fixo instalado. Para isto foi utilizada a técnica de multiplex PCR (Polymerase Chain Reaction) para investigar a presença das bactérias pigmentadoras de negro: Prevotella nigrescens e Prevotella intermedia e as bactérias não pigmentadoras de negro: Streptococcus mutans e Actinomyces spp nos biofilmes. A amostra consistiu de 52 pacientes, 25 do gênero feminino e 27 do gênero masculino. A amostra foi dividida em dois grupos: Grupo I: 26 pacientes portadores de manchas e Grupo II: 26 pacientes não portadores de manchas. Do total da amostra, 20 pacientes estavam sob terapia ortodôntica fixa, utilizando bráquetes de aço inoxidável. Os resultados mostraram que tanto no grupo I, quanto no grupo II, em 61,5% dos pacientes foi detectada pelo menos uma das bactérias investigadas. P. nigrescens foi a bactéria mais frequentemente detectada no Grupo I (30,8%) e no Grupo II (46,1%), enquanto P. intermedia foi detectada em 3,8% no Grupo I e 11,5% no Grupo II. As bactérias não pigmentadoras de negro foram encontradas em frequências similares nos Grupos I e II (19,2% versus 11,5% para Actinomyces spp e 23,1% versus 30,7% para S. mutans). Não foram encontradas diferenças estatisticamente significativas quando comparando as frequências de cada bactéria entre os grupos, indicando que os perfis bacterianos são similares entre pacientes que apresentam e os que não apresentam manchas extrínsecas negras. Quando analisadas as frequências das bactérias nos biofilmes nas manchas dentárias extrínsecas negras dos pacientes portadores de aparelho ortodôntico, os resultados indicaram que o aparelho não alterou a frequência das bactérias encontradas, porém, foi observada redução significante das associações entre as diferentes bactérias no biofilme das manchas extrínsecas negras (p<0,05).
35

Kennzeichnung von Schlachtnebenprodukten zur sicheren Klassifizierung als tierische Nebenprodukte der Kategorie 3 und zur Verbesserung ihrer Verfolgbarkeit im Warenstrom / Marking of slaughter by-products for safe classification as animal by-products from category 3 and for an improved traceability of commodity flows

Schmidt, Bianca 27 October 2011 (has links) (PDF)
Die seit 2004 in Deutschland bekannt gewordenen Fälle der illegalen Rückführung und irrtümlichen Fehlverbringung von gemäß der Verordnung (EG) Nr. 1774/2002 nicht für den Genuss durch den Menschen bestimmten tierischen Nebenprodukten (TNP) der Kategorie 3 in die Lebensmittelkette haben zu der politischen Diskussion beigetragen, ob die Pflicht der Materialidentifizierbarkeit durch das Getrennthalten TNP am Ort des Anfalls sowie die ausschließliche Kennzeichnung ihrer Transportbehälter bei der Beförderung einen ausreichenden Schutz der Verbraucher garantieren können. Um eine ordnungsgemäße Verwendung TNP der Kategorie 3 sicherzustellen, hat der Bundesrat ihre unmittelbare und eindeutige Kennzeichnung, z.B. durch Farbstoffe, gefordert. Ziel dieser Arbeit war es, einen geeigneten, futtermittelrechtlich zugelassenen Marker für Schlachtnebenprodukte der Kategorie 3 zu erörtern, der eine technisch praktikable, vom Ort des Anfalls bis zum Verarbeitungsbetrieb optisch eindeutige, dauerhafte und nach der Verarbeitung nachweisbare sowie umwelt- und wirtschaftsverträgliche Markierung von Schlachtnebenprodukten zur sicheren Verfolgbarkeit ihrer bestimmungsgemäßen Verwendung als TNP der Kategorie 3 ermöglicht, um ihren Eintrag in die Lebensmittelkette zu unterbinden, ohne die Neutralität der Endprodukte bei der Verwendung markierter TNP als Rohstoffe für Futtermittel zu beeinträchtigen. Für die Markierung von Schlachtnebenprodukten mittels Sprühsystemen wurden für Futtermittel zugelassene, färbende Zusatzstoffe (Verordnung (EG) Nr. 1831/2003) sowie in der medizinischen Diagnostik etablierte Fluoreszenz-Farbstoffe ausgewählt und hinsichtlich der Eindeutigkeit ihrer Markierung, ihrer Farbhaltung nach Bearbeitung sowie ihrer optischen Neutralität in Lebens- und Futtermitteln, die aus markierten TNP hergestellt worden sind, von fünf ungeschulten Prüfpersonen im Rahmen einer einfach beschreibenden, sensorischen und unabhängigen Prüfung gemäß §35 LMBG (L 00.90-6, ASU) beurteilt. Die Ergebnisse der sensorischen Prüfung wurden mit den RGB-Farbprofilen der markierten und nicht markierten TNP vergleichend analysiert. Zum Nachweis des irrtümlichen oder vorsätzlichen Eintrags von mit den ausgewählten Markerfarbstoffen markierten TNP in Lebensmitteln konnten die Analyseverfahren Dünnschichtchromatographie (DC), optische Emissionsspektrometrie mit induktiv gekoppeltem Hochfrequenzplasma (ICP-OES), Photometrie sowie die Fluoreszenzspektrometrie hinsichtlich ihrer Anwendbarkeit untersucht werden. Die Untersuchung der sensorischen Neutralität der Markerfarbstoffe im Endprodukt Futtermittel erfolgte unter anderem durch einen Futtermittelpräferenzversuch an neun Hunden der Rasse Beagle. Brillantsäuregrün E142 (1,3 mg E142/kg TNP) konnte auf Grund der Eindeutigkeit der Markierung von Schlachtnebenprodukten durch die gegenüber den nativen TNP signifikant unterschiedlichen Rot-Farbintensitäten bei gleichzeitiger Neutralität in den Endprodukten (Lebens- oder Futtermittel) und einer guten bis sehr guten Farbhaltung nach dem Waschen der Nebenprodukte, der Kühl- (8°C über zwei Tage) sowie Gefrierlagerung (-25°C über 14 Tage) und dem Verwenden einer 14, 90 als auch 150 Tage gelagerten Farbstofflösung in Kombination mit dem chemisch nachweisbaren Titandioxid (90 mg E171/ kg TNP) als Markerfarbstofflösung zur eindeutigen Markierung von Nebenprodukten der Schlachtung am Ort ihres Anfalls selektiert werden. Die für die Markierung bestimmten Dosierungen der Markerfarbstoffe gelten für Tiere und Menschen als unbedenklich. Die mit den färbenden Zusatzstoffen E142 und E171 markierten Nebenprodukte der Schlachtung können mittels DC (Nachweisgrenze: ≥7,5 µg E142/kg Probe) beziehungsweise ICP-OES und Photometrie (Nachweisgrenze ICP-OES: 8,3 mg E171/kg Probe) ab einem eingebrachten Anteil von 0,55% (DC: E142) beziehungsweise 9% (ICP-OES: E171) in diversen Produkten (Lebens- oder Futtermittel) nachgewiesen werden. In den chemisch und thermisch extrahierten Fetten aus markierten, fettreichen TNP waren die Farbstoffe E142 und E171 jedoch nicht nachweisbar. Eine Fluoreszenzmarkierung TNP kann hingegen nicht präferiert werden, da nicht markierte Nebenprodukte der Schlachtung eine sichtbare und fluoreszenzspektrometrisch nachweisbare Autofluoreszenz aufweisen und in den thermisch verarbeiteten Produkten keine für die Fluoreszenz-farbstoffe charakteristischen Absorptions- und Emissionsspektren nachweisbar waren. Die Markierung mittels Sprühtechnik erscheint unter den Aspekten Substanzverlust und adaptierter Markerfarbstoff pro Kilogramm TNP praktikabel. Die im Labor bestimmte Markierungszeit für TNP (5 sec./kg) ist unter Einbeziehung der Durchsatzraten am Schlachthof als zu lang zu bewerten. Durch die rückstandsfreie Entfernung der Farbstoffe von Edelstahl- und glatten Kunststoffflächen sowie glasierten Fliesen ergeben sich keine Nachteile der Markierung TNP für die Produktion von Futtermitteln und technischen Erzeugnissen. Die in dem Präferenzversuch untersuchten Futtermittel für Hunde aus markierten TNP zeigten keine Abweichungen von der handelsüblichen sensorischen Produktqualität und hinsichtlich ihrer Haltbarkeit durch Sterilisation (F0-Wert). Mit E142 und E171 markierte TNP (Kat. 3) eignen sich somit als Rohstoffe zur Herstellung von Heimtierfuttermitteln. Bei Anwendung einer Kombinationsfarbstofflösung (E142 und E171) würden die für die Marker anfallenden Kosten pro Tonne TNP bis zu 33 Euro betragen. Bei der ausschließlichen Verwendung von E142, welches der optisch eindeutig markierende Farbstoff ist und das eine hohe Sensitivität im dünnschichtchromatographischen Nachweis zeigt, würden die Kosten 1,70 bis 3,40 Euro/t betragen. Bisher konnte kein EU-einheitlicher Rechtsrahmen zur Markierung TNP der Kategorie 3 gestaltet werden. Die politische Diskussion wird aber vor allem national fortgesetzt. / Since 2004 several illegal or aberrant transfers of animal by-products (ABP) from category 3 (according to Regulation (EC) No. 1774/2002: not intended for food production) back into food chain, have led to the political discussion, whether duty of material identifiability by separate storing of ABP on site and sole labeling of containers during transport are sufficient to protect consumers from ABP not intended for human consumption. To guarantee adequate utilisation of ABP from category 3, the German Federal Council claimed for an immediate and conclusive marking of ABP by dyeing or similar solutions. This study was implemented to define a convenient, registered feed additive for dyeing of slaughter by-products from category 3, which realize a feasible, from extraction to processing visually conclusive, long-lasting, traceable as well as sustainable and cost-effective marking on site to ensure traceability of intended utilisation as ABP from category 3 and to prevent their influx into food chain, without an impairment of the neutrality of products (e.g. pet food) made from marked ABP. For marking of slaughter by-products by air spraying device, registered colouring feed additives (Regulation (EC) No. 1831/2003) as well as diagnostically established fluorescence pigments were selected and investigated regarding their marking unambiguousness, colour retention after processing and visual neutrality in food and feed made from marked ABP by evaluation of five untrained judging persons in the course of a simply delineative, sensorial and impartial test (official list of analysis methods, ASU §35 LMBG, L 00.90-6), and by comparative RGB-colour measurement of images scanned from stained ABP samples. Detection of aberrant or deliberate discharge of marked ABP into food production was evaluated by investigation of thin layer chromatography (TLC), inductively coupled plasma optical emission spectrometry (ICP-OES), photometry and fluorescence spectrometry. Neutrality of marking feed additives in feedstuff was determined by a feeding preference test with nine dogs of the Beagle breed using pet food made from unmarked und marked ABP. Lissamine Green E142 (1,3 mg E142 per kg ABP) was selected as marker dye for slaughter by-products on site based on its unambiguousness of marking due to the significant different red-colour intensity compared to the non-marked ABP as well as the simultaneous neutrality of the colouring additive E142 in the final products feed and food. Colour retention of E142 marking was conclusive with regard to handling by washing, cold (8°C for two days) respectively fridge storage (-25°C for 14 days) and utilisation of a 14-, 90- and 150-days-stored marker solution. For marking, Lissamine Green was combined with the chemical detectable and registered food colour titanium dioxide (E171: 90 mg/kg ABP). The marker additives are classified as safe for humans and animals within the preferred concentrations for colouring ABP. With E142 und E171 marked ABP were traceable in food and feed using detection methods TLC (limit of detection: ≥7,5 µg E142 per kg sample), photometry and ICP-OES (limit of detection: ≥8,3 mg E171 per kg sample) at a proportion of 0,55% (TLC: E142) respectively 9% (ICP-OES: E171), whereas the named markers were not detectable in chemical and thermal extracted fats produced from marked high-fat ABP. Based on the visible and fluorescence spectrometric detectable autofluorescence of animal tissues as well as the uncharacteristic emission and absorption spectra of fluorescence pigments in processed ABP, fluorescence markers are not preferential for marking of slaughter by-products from category 3. Marking of slaughter by-products by air spraying device appeared practicable in due consideration of marker depletion and tissue-adapted marker per kg ABP. Current time of marking under laboratory conditions (5 sec. per kg ABP) must be graded as too long, regarding high transfer rates in slaughterhouses. Concerning the residue-free cleaning of stainless steel and even plastic surfaces from the marker solution, the utilisation of marked ABP for manufacturing of feed and technical products is unproblematic. Investigated pet food samples produced from marked ABP were from comparable commercial sensory product quality and showed no deviation of normal storability due to sterilisation. In conclusion, with E142 and E171 visible marked ABP from category 3 are suitable as crude materials for pet food production. The application of the combined marker solution (E142 and E171) have to be evaluated as comparative expensive (33 Euro per ton ABP), while the exclusive application of E142 as the optic conclusive and sensitive detectable marker for ABP is associated with sustainable costs from 1,70 to 3,40 Euro per ton ABP. To date, an EU-common regulatory framework for marking of ABP from category 3 could not be specified. Nevertheless the political discussion is still continued, especially in Germany.
36

Kennzeichnung von Schlachtnebenprodukten zur sicheren Klassifizierung als tierische Nebenprodukte der Kategorie 3 und zur Verbesserung ihrer Verfolgbarkeit im Warenstrom: Kennzeichnung von Schlachtnebenprodukten zur sicheren Klassifizierung als tierische Nebenprodukte der Kategorie 3 und zur Verbesserung ihrerVerfolgbarkeit im Warenstrom

Schmidt, Bianca 28 June 2011 (has links)
Die seit 2004 in Deutschland bekannt gewordenen Fälle der illegalen Rückführung und irrtümlichen Fehlverbringung von gemäß der Verordnung (EG) Nr. 1774/2002 nicht für den Genuss durch den Menschen bestimmten tierischen Nebenprodukten (TNP) der Kategorie 3 in die Lebensmittelkette haben zu der politischen Diskussion beigetragen, ob die Pflicht der Materialidentifizierbarkeit durch das Getrennthalten TNP am Ort des Anfalls sowie die ausschließliche Kennzeichnung ihrer Transportbehälter bei der Beförderung einen ausreichenden Schutz der Verbraucher garantieren können. Um eine ordnungsgemäße Verwendung TNP der Kategorie 3 sicherzustellen, hat der Bundesrat ihre unmittelbare und eindeutige Kennzeichnung, z.B. durch Farbstoffe, gefordert. Ziel dieser Arbeit war es, einen geeigneten, futtermittelrechtlich zugelassenen Marker für Schlachtnebenprodukte der Kategorie 3 zu erörtern, der eine technisch praktikable, vom Ort des Anfalls bis zum Verarbeitungsbetrieb optisch eindeutige, dauerhafte und nach der Verarbeitung nachweisbare sowie umwelt- und wirtschaftsverträgliche Markierung von Schlachtnebenprodukten zur sicheren Verfolgbarkeit ihrer bestimmungsgemäßen Verwendung als TNP der Kategorie 3 ermöglicht, um ihren Eintrag in die Lebensmittelkette zu unterbinden, ohne die Neutralität der Endprodukte bei der Verwendung markierter TNP als Rohstoffe für Futtermittel zu beeinträchtigen. Für die Markierung von Schlachtnebenprodukten mittels Sprühsystemen wurden für Futtermittel zugelassene, färbende Zusatzstoffe (Verordnung (EG) Nr. 1831/2003) sowie in der medizinischen Diagnostik etablierte Fluoreszenz-Farbstoffe ausgewählt und hinsichtlich der Eindeutigkeit ihrer Markierung, ihrer Farbhaltung nach Bearbeitung sowie ihrer optischen Neutralität in Lebens- und Futtermitteln, die aus markierten TNP hergestellt worden sind, von fünf ungeschulten Prüfpersonen im Rahmen einer einfach beschreibenden, sensorischen und unabhängigen Prüfung gemäß §35 LMBG (L 00.90-6, ASU) beurteilt. Die Ergebnisse der sensorischen Prüfung wurden mit den RGB-Farbprofilen der markierten und nicht markierten TNP vergleichend analysiert. Zum Nachweis des irrtümlichen oder vorsätzlichen Eintrags von mit den ausgewählten Markerfarbstoffen markierten TNP in Lebensmitteln konnten die Analyseverfahren Dünnschichtchromatographie (DC), optische Emissionsspektrometrie mit induktiv gekoppeltem Hochfrequenzplasma (ICP-OES), Photometrie sowie die Fluoreszenzspektrometrie hinsichtlich ihrer Anwendbarkeit untersucht werden. Die Untersuchung der sensorischen Neutralität der Markerfarbstoffe im Endprodukt Futtermittel erfolgte unter anderem durch einen Futtermittelpräferenzversuch an neun Hunden der Rasse Beagle. Brillantsäuregrün E142 (1,3 mg E142/kg TNP) konnte auf Grund der Eindeutigkeit der Markierung von Schlachtnebenprodukten durch die gegenüber den nativen TNP signifikant unterschiedlichen Rot-Farbintensitäten bei gleichzeitiger Neutralität in den Endprodukten (Lebens- oder Futtermittel) und einer guten bis sehr guten Farbhaltung nach dem Waschen der Nebenprodukte, der Kühl- (8°C über zwei Tage) sowie Gefrierlagerung (-25°C über 14 Tage) und dem Verwenden einer 14, 90 als auch 150 Tage gelagerten Farbstofflösung in Kombination mit dem chemisch nachweisbaren Titandioxid (90 mg E171/ kg TNP) als Markerfarbstofflösung zur eindeutigen Markierung von Nebenprodukten der Schlachtung am Ort ihres Anfalls selektiert werden. Die für die Markierung bestimmten Dosierungen der Markerfarbstoffe gelten für Tiere und Menschen als unbedenklich. Die mit den färbenden Zusatzstoffen E142 und E171 markierten Nebenprodukte der Schlachtung können mittels DC (Nachweisgrenze: ≥7,5 µg E142/kg Probe) beziehungsweise ICP-OES und Photometrie (Nachweisgrenze ICP-OES: 8,3 mg E171/kg Probe) ab einem eingebrachten Anteil von 0,55% (DC: E142) beziehungsweise 9% (ICP-OES: E171) in diversen Produkten (Lebens- oder Futtermittel) nachgewiesen werden. In den chemisch und thermisch extrahierten Fetten aus markierten, fettreichen TNP waren die Farbstoffe E142 und E171 jedoch nicht nachweisbar. Eine Fluoreszenzmarkierung TNP kann hingegen nicht präferiert werden, da nicht markierte Nebenprodukte der Schlachtung eine sichtbare und fluoreszenzspektrometrisch nachweisbare Autofluoreszenz aufweisen und in den thermisch verarbeiteten Produkten keine für die Fluoreszenz-farbstoffe charakteristischen Absorptions- und Emissionsspektren nachweisbar waren. Die Markierung mittels Sprühtechnik erscheint unter den Aspekten Substanzverlust und adaptierter Markerfarbstoff pro Kilogramm TNP praktikabel. Die im Labor bestimmte Markierungszeit für TNP (5 sec./kg) ist unter Einbeziehung der Durchsatzraten am Schlachthof als zu lang zu bewerten. Durch die rückstandsfreie Entfernung der Farbstoffe von Edelstahl- und glatten Kunststoffflächen sowie glasierten Fliesen ergeben sich keine Nachteile der Markierung TNP für die Produktion von Futtermitteln und technischen Erzeugnissen. Die in dem Präferenzversuch untersuchten Futtermittel für Hunde aus markierten TNP zeigten keine Abweichungen von der handelsüblichen sensorischen Produktqualität und hinsichtlich ihrer Haltbarkeit durch Sterilisation (F0-Wert). Mit E142 und E171 markierte TNP (Kat. 3) eignen sich somit als Rohstoffe zur Herstellung von Heimtierfuttermitteln. Bei Anwendung einer Kombinationsfarbstofflösung (E142 und E171) würden die für die Marker anfallenden Kosten pro Tonne TNP bis zu 33 Euro betragen. Bei der ausschließlichen Verwendung von E142, welches der optisch eindeutig markierende Farbstoff ist und das eine hohe Sensitivität im dünnschichtchromatographischen Nachweis zeigt, würden die Kosten 1,70 bis 3,40 Euro/t betragen. Bisher konnte kein EU-einheitlicher Rechtsrahmen zur Markierung TNP der Kategorie 3 gestaltet werden. Die politische Diskussion wird aber vor allem national fortgesetzt. / Since 2004 several illegal or aberrant transfers of animal by-products (ABP) from category 3 (according to Regulation (EC) No. 1774/2002: not intended for food production) back into food chain, have led to the political discussion, whether duty of material identifiability by separate storing of ABP on site and sole labeling of containers during transport are sufficient to protect consumers from ABP not intended for human consumption. To guarantee adequate utilisation of ABP from category 3, the German Federal Council claimed for an immediate and conclusive marking of ABP by dyeing or similar solutions. This study was implemented to define a convenient, registered feed additive for dyeing of slaughter by-products from category 3, which realize a feasible, from extraction to processing visually conclusive, long-lasting, traceable as well as sustainable and cost-effective marking on site to ensure traceability of intended utilisation as ABP from category 3 and to prevent their influx into food chain, without an impairment of the neutrality of products (e.g. pet food) made from marked ABP. For marking of slaughter by-products by air spraying device, registered colouring feed additives (Regulation (EC) No. 1831/2003) as well as diagnostically established fluorescence pigments were selected and investigated regarding their marking unambiguousness, colour retention after processing and visual neutrality in food and feed made from marked ABP by evaluation of five untrained judging persons in the course of a simply delineative, sensorial and impartial test (official list of analysis methods, ASU §35 LMBG, L 00.90-6), and by comparative RGB-colour measurement of images scanned from stained ABP samples. Detection of aberrant or deliberate discharge of marked ABP into food production was evaluated by investigation of thin layer chromatography (TLC), inductively coupled plasma optical emission spectrometry (ICP-OES), photometry and fluorescence spectrometry. Neutrality of marking feed additives in feedstuff was determined by a feeding preference test with nine dogs of the Beagle breed using pet food made from unmarked und marked ABP. Lissamine Green E142 (1,3 mg E142 per kg ABP) was selected as marker dye for slaughter by-products on site based on its unambiguousness of marking due to the significant different red-colour intensity compared to the non-marked ABP as well as the simultaneous neutrality of the colouring additive E142 in the final products feed and food. Colour retention of E142 marking was conclusive with regard to handling by washing, cold (8°C for two days) respectively fridge storage (-25°C for 14 days) and utilisation of a 14-, 90- and 150-days-stored marker solution. For marking, Lissamine Green was combined with the chemical detectable and registered food colour titanium dioxide (E171: 90 mg/kg ABP). The marker additives are classified as safe for humans and animals within the preferred concentrations for colouring ABP. With E142 und E171 marked ABP were traceable in food and feed using detection methods TLC (limit of detection: ≥7,5 µg E142 per kg sample), photometry and ICP-OES (limit of detection: ≥8,3 mg E171 per kg sample) at a proportion of 0,55% (TLC: E142) respectively 9% (ICP-OES: E171), whereas the named markers were not detectable in chemical and thermal extracted fats produced from marked high-fat ABP. Based on the visible and fluorescence spectrometric detectable autofluorescence of animal tissues as well as the uncharacteristic emission and absorption spectra of fluorescence pigments in processed ABP, fluorescence markers are not preferential for marking of slaughter by-products from category 3. Marking of slaughter by-products by air spraying device appeared practicable in due consideration of marker depletion and tissue-adapted marker per kg ABP. Current time of marking under laboratory conditions (5 sec. per kg ABP) must be graded as too long, regarding high transfer rates in slaughterhouses. Concerning the residue-free cleaning of stainless steel and even plastic surfaces from the marker solution, the utilisation of marked ABP for manufacturing of feed and technical products is unproblematic. Investigated pet food samples produced from marked ABP were from comparable commercial sensory product quality and showed no deviation of normal storability due to sterilisation. In conclusion, with E142 and E171 visible marked ABP from category 3 are suitable as crude materials for pet food production. The application of the combined marker solution (E142 and E171) have to be evaluated as comparative expensive (33 Euro per ton ABP), while the exclusive application of E142 as the optic conclusive and sensitive detectable marker for ABP is associated with sustainable costs from 1,70 to 3,40 Euro per ton ABP. To date, an EU-common regulatory framework for marking of ABP from category 3 could not be specified. Nevertheless the political discussion is still continued, especially in Germany.
37

I like it dirty

Pontén, Stina January 2018 (has links)
Using dirt and cleaning as a point of departure, I have examined how categorization and intentionality affects our perception of value. The work is partly performative in its nature where this performativity sets the limelight on the transition between categories: From dirt to craft, from irrational behaviour to art. In the artistic process, I have used coffee rings on table cloths, shoeprints on wallpapers and  the act of mopping as a means of questioning. Through this, I also reveal and question hierarchies in society. The essay discusses and theoretically relates to the artistic work. / Med utgångspunkt i smuts har jag underökt hur kategorisering och intentionalitet påverkar vår uppfattning av värde. Arbetet är delvis performativt till sin natur, där denna performativitet sätter fokus på övergången från en kategori till en annan: Från smuts till konsthantverk, från irrationellt beteende till konst. I den konstnärliga processen har jag använt mig av kafferingar på dukar, skoavtryck på tapeter och moppande av golv som medel för ifrågasättande. PÅ detta vis blottlägger och ifrågasätter jag hierarkier i samhället. I uppsatsen diskuterar jag och relaterar teoretiskt till det konstnärliga arbetet.
38

Work-related wellness of information technology professionals in South Africa / C. Westerman

Westerman, Christelle January 2005 (has links)
Thesis (Ph.D. (Industrial Psychology))--North-West University, Vaal Triangle Campus, 2006.
39

Work-related wellness of information technology professionals in South Africa / C. Westerman

Westerman, Christelle January 2005 (has links)
The information technology industry is considered to be one of the most demanding industries, with significant social, physical and psychological consequences for the wellbeing of the information technology professional. Work wellness and general psychological well-being plays an important role in the well-being of the information technology professional. The measurement of work-related wellness requires valid, reliable and culturally fair measuring instruments. However research on work wellness and occupational well-being in South Africa is lacking, especially in the information technology context. A lack of norms for work-related wellness in South Africa makes the identification of work-related wellness in the information technology industry difficult. Consequently, investigating the reliability, validity, equivalence and bias of work-related well-being measuring instruments would result in the standardisation of work wellness (consisting of burnout and engagement) and occupational well-being, suitable for use in the multicultural information technology industry setting. Moreover, the operationalisation of work wellness, as well as an inclusive model regarding the work-related wellness of information technology professionals that includes work wellness and occupational wellbeing are lacking in the South African literature. The objectives of this research were to standardise the measurement of work wellness for information technology professionals in South Africa, to develop and test a model of occupational well-being for information technology professionals in South Africa, to develop and test a comprehensive model of work-related wellness for information technology professionals in South Africa (consisting of work wellness and occupational well-being), and to test for moderating effects of affectivity in the experience of mark related well-being of information technology professionals in South Africa. The research consists of three separate articles, each consisting of a brief literature overview and an empirical study. A cross-sectional survey design with a snowball sample (n = 214) of information technology professionals in South Africa was used. Adapted versions of the Maslach Burnout Inventory - General Survey (MBI-GS) and Gtrecht Work Engagement Scale (UWES), as well as the Satisfaction with Life Scale (SWLS), Affectometer 2 (AFM-2), Life Orientation Test - Revised (LOT-R), Organisational Commitment Questionnaire (OC-Q), Information Technology Job Characteristics Inventory (ITJCI), as well as the Health scale of the Organisational Screening Evaluation Tool (ASSET) and a biographical questionnaire were used. Descriptive statistics, analysis of variance, correlations, exploratory factor analysis and structural equation modeling were used. Exploratory factor analysis confirmed a two-factor model for the MBI-GS consisting of a combined Burnout factor and Professional Efficacy, while a one-factor model was found for the UWES, namely Engagement, with acceptable internal consistencies. Exploratory second-order factor analysis confirmed a two-factor, culturally fair model of work wellness for information technology professionals in South Africa, consisting of burnout and work engagement. Item bias analysis revealed no evidence of bias for the MBI-GS, while uniform bias was found for two items (Items 7 and 12) of the UWES. Construct equivalence in terms of work wellness was obtained for the different language groups in the sample. The results confirmed a four-factor model of occupational well-being for information technology professionals in South Africa, namely negative and positive work wellness, organisational commitment and general psychological well-being. The model of occupational well-being was found to be equivalent across language groups, except for general psychological well-being, which seemed to differ for the non-mother-tongue English language speakers. In terms of work-related wellness, a model consisting of work wellness and occupational well-being was constructed and uccessfully tested. Structural equation analysis confirmed main effects for negative affectivity in terms of burnout and engagement, while main effects were confirmed for burnout, ill-health and engagement in terms of positive affectivity. Interaction effects for affectivity were not confirmed in the model of work-related wellness of information technology professionals in South Africa. Recommendations for the organisation and future research were made / Thesis (Ph.D. (Industrial Psychology))--North-West University, Vaal Triangle Campus, 2006.
40

Work-related wellness of information technology professionals in South Africa / C. Westerman

Westerman, Christelle January 2005 (has links)
The information technology industry is considered to be one of the most demanding industries, with significant social, physical and psychological consequences for the wellbeing of the information technology professional. Work wellness and general psychological well-being plays an important role in the well-being of the information technology professional. The measurement of work-related wellness requires valid, reliable and culturally fair measuring instruments. However research on work wellness and occupational well-being in South Africa is lacking, especially in the information technology context. A lack of norms for work-related wellness in South Africa makes the identification of work-related wellness in the information technology industry difficult. Consequently, investigating the reliability, validity, equivalence and bias of work-related well-being measuring instruments would result in the standardisation of work wellness (consisting of burnout and engagement) and occupational well-being, suitable for use in the multicultural information technology industry setting. Moreover, the operationalisation of work wellness, as well as an inclusive model regarding the work-related wellness of information technology professionals that includes work wellness and occupational wellbeing are lacking in the South African literature. The objectives of this research were to standardise the measurement of work wellness for information technology professionals in South Africa, to develop and test a model of occupational well-being for information technology professionals in South Africa, to develop and test a comprehensive model of work-related wellness for information technology professionals in South Africa (consisting of work wellness and occupational well-being), and to test for moderating effects of affectivity in the experience of mark related well-being of information technology professionals in South Africa. The research consists of three separate articles, each consisting of a brief literature overview and an empirical study. A cross-sectional survey design with a snowball sample (n = 214) of information technology professionals in South Africa was used. Adapted versions of the Maslach Burnout Inventory - General Survey (MBI-GS) and Gtrecht Work Engagement Scale (UWES), as well as the Satisfaction with Life Scale (SWLS), Affectometer 2 (AFM-2), Life Orientation Test - Revised (LOT-R), Organisational Commitment Questionnaire (OC-Q), Information Technology Job Characteristics Inventory (ITJCI), as well as the Health scale of the Organisational Screening Evaluation Tool (ASSET) and a biographical questionnaire were used. Descriptive statistics, analysis of variance, correlations, exploratory factor analysis and structural equation modeling were used. Exploratory factor analysis confirmed a two-factor model for the MBI-GS consisting of a combined Burnout factor and Professional Efficacy, while a one-factor model was found for the UWES, namely Engagement, with acceptable internal consistencies. Exploratory second-order factor analysis confirmed a two-factor, culturally fair model of work wellness for information technology professionals in South Africa, consisting of burnout and work engagement. Item bias analysis revealed no evidence of bias for the MBI-GS, while uniform bias was found for two items (Items 7 and 12) of the UWES. Construct equivalence in terms of work wellness was obtained for the different language groups in the sample. The results confirmed a four-factor model of occupational well-being for information technology professionals in South Africa, namely negative and positive work wellness, organisational commitment and general psychological well-being. The model of occupational well-being was found to be equivalent across language groups, except for general psychological well-being, which seemed to differ for the non-mother-tongue English language speakers. In terms of work-related wellness, a model consisting of work wellness and occupational well-being was constructed and uccessfully tested. Structural equation analysis confirmed main effects for negative affectivity in terms of burnout and engagement, while main effects were confirmed for burnout, ill-health and engagement in terms of positive affectivity. Interaction effects for affectivity were not confirmed in the model of work-related wellness of information technology professionals in South Africa. Recommendations for the organisation and future research were made / Thesis (Ph.D. (Industrial Psychology))--North-West University, Vaal Triangle Campus, 2006.

Page generated in 0.074 seconds