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Journal articles on the topic "Delayed strain"
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Wang, Shifeng, Yuhua Li, Giorgio Scarpellini, Wei Kong, HuoYing Shi, Chang-Ho Baek, Bronwyn Gunn, et al. "Salmonella Vaccine Vectors Displaying Delayed Antigen Synthesis InVivo To Enhance Immunogenicity." Infection and Immunity 78, no. 9 (July 6, 2010): 3969–80. http://dx.doi.org/10.1128/iai.00444-10.
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ABSTRACTWe have developed a regulated delayed antigen synthesis (RDAS) system for use in recombinant attenuatedSalmonellavaccine (RASV) strains to enhance immune responses by reducing the adverse effects of high-level antigen synthesis. This system includes a chromosomal repressor gene,lacI, expressed from the arabinose-regulatedaraCPBADpromoter. LacI serves to regulate expression from a plasmid promoter, Ptrc, that directs antigen synthesis. In the presence of arabinose LacI is produced, which binds to Ptrc, blocking antigen synthesis.In vivo, an arabinose-poor environment, the concentration of LacI decreases with each cell division, allowing increased antigen synthesis. To optimize the system and for comparison, we altered thelacIribosome-binding site, start codon, and/or codon content to construct RDAS strains χ9095, χ9959, and χ9241, synthesizing from low to high levels of LacI, respectively, and non-RDAS strain χ9555 as a control. We evaluated this system with two test antigens, the green fluorescent protein for initialin vitroassessment and theStreptococcus pneumoniaePspA protein for validation of our system in mice. All RASV strains expressing PspA generated high antilipopolysaccharide antibody titers, indicating that expression oflacIdid not interfere with the capacity to induce an immune response. Strain χ9241 induced significantly higher anti-PspA IgG and IgA antibody titers than strain χ9555, which expressed PspA constitutively. Anti-PspA antibody titers were inversely correlated to the level of LacI synthesis. Strain χ9241 also induced significantly greater protective efficacy against challenge with virulentS. pneumoniae. These results suggest that regulated delayed antigen synthesis is useful for improving immunogenicity of RASV strains.
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Mizumoto, Hiroyuki, Yuji Tomaru, Yoshitake Takao, Yoko Shirai, and Keizo Nagasaki. "Diverse Responses of the Bivalve-Killing Dinoflagellate Heterocapsa circularisquama to Infection by a Single-Stranded RNA Virus." Applied and Environmental Microbiology 74, no. 10 (March 21, 2008): 3105–11. http://dx.doi.org/10.1128/aem.02190-07.
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ABSTRACT Viruses are believed to be significant pathogens for phytoplankton. Usually, they infect a single algal species, and often their infection is highly strain specific. However, the detailed molecular background of the strain specificity and its ecological significance have not been sufficiently understood. Here, we investigated the temporal changes in viral RNA accumulation and virus-induced cell lysis using a bloom-forming dinoflagellate Heterocapsa circularisquama and its single-stranded RNA virus, HcRNAV. We observed at least three host response patterns to virus inoculation: sensitive, resistant, and delayed lysis. In the sensitive response, the host cell culture was permissive for viral RNA replication and apparent cell lysis was observed; in contrast, resistant cell culture was nonpermissive for viral RNA replication and not lysed. In the delayed-lysis response, although viral RNA replication occurred, virus-induced cell lysis was faint and remarkably delayed. In addition, the number of infectious virus particles released to the culture supernatant at 12 days postinoculation was comparable to that of the sensitive strain. By further analysis, a few strains were characterized as variants of the delayed-lysis strain. These observations indicate that the response of H. circularisquama to HcRNAV infection is highly diverse.
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Parra, Araceli, Carmen Ponte, Carlos Cenjor, Carmen Martínez-Marín, and Francisco Soriano. "Effect of Antibiotic Treatment Delay on Therapeutic Outcome of Experimental Acute Otitis Media Caused by Streptococcus pneumoniae Strains with Different Susceptibilities to Amoxicillin." Antimicrobial Agents and Chemotherapy 48, no. 3 (March 2004): 860–66. http://dx.doi.org/10.1128/aac.48.3.860-866.2004.
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ABSTRACT The effect of delayed administration of amoxicillin on the course of acute otitis media (AOM) caused by two Streptococcus pneumoniae strains with different susceptibilities to amoxicillin (MICs of 0.016 and 1 μg/ml for strains A and B, respectively) was evaluated in the gerbil model. The organisms were inoculated by transbullar challenge into the middle ear, and antibiotic treatment was administered at various times thereafter. The bacteriological and clinical efficacies of treatment diminished significantly with the delay of antibiotic administration. The bacterial eradication rates when antibiotic treatment was started at 2, 5, 8, 18, and 21 h post-bacterial inoculation were different for both strains (95, 95, 90, 55, and 55% for strain A and 95, 95, 65, 10, and 0% for strain B). Results of further experiments using strain B with higher antibiotic doses and numbers of administrations and different follow-up times indicate that the failures observed with the delayed administration were not related to the bacterial burden, selection of antibiotic-resistant mutants, or inadequate pharmacodynamic parameters. Such failures may be related to the metabolic bacterial status. The delayed amoxicillin treatment of AOM caused by S. pneumoniae may lead to therapeutic failures, mainly when organisms with diminished antibiotic susceptibility are involved.
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Shi, Huoying, Shifeng Wang, and Roy Curtiss. "Evaluation of Regulated Delayed Attenuation Strategies for Salmonella enterica Serovar Typhi Vaccine Vectors in Neonatal and Infant Mice." Clinical and Vaccine Immunology 20, no. 6 (April 24, 2013): 931–44. http://dx.doi.org/10.1128/cvi.00003-13.
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ABSTRACTWe developed regulated delayed attenuation strategies forSalmonellavaccine vectors. In this study, we evaluated the combination of these strategies in recombinant attenuatedSalmonella entericaserovar Typhi andSalmonella entericaserovar Typhimurium vaccine vectors with similar genetic backgroundsin vitroandin vivo. Our goal is to develop a vaccine to preventStreptococcus pneumoniaeinfection in newborns; thus, all strains delivered a pneumococcal antigen PspA and the impact of maternal antibodies was evaluated. The results showed that all strains with the regulated delayed attenuated phenotype (RDAP) displayed an invasive ability stronger than that of theS.Typhi vaccine strain, Ty21a, but weaker than that of their corresponding wild-type parental strains. The survival curves of different RDAP vaccine vectorsin vitroandin vivoexhibited diverse regulated delayed attenuation kinetics, which was different fromS.Typhi Ty21a and the wild-type parental strains. Under the influence of maternal antibody, the persistence of theS.Typhimurium RDAP strain displayed a regulated delayed attenuation trend in nasal lymphoid tissue (NALT), lung, and Peyer's patches, while the persistence ofS.Typhi RDAP strains followed the curve only in NALT. The bacterial loads ofS.Typhi RDAP strains were lower in NALT, lung, and Peyer's patches in mice born to immune mothers than in those born to naive mothers. In accordance with these results, RDAP vaccine strains induced high titers of IgG antibodies against PspA and againstSalmonellalipopolysaccharides. Immunization of mothers withS.Typhi RDAP strains enhanced the level of vaginal mucosal IgA, gamma interferon (IFN-γ), and interleukin 4 (IL-4) and resulted in a higher level of protection againstS. pneumoniaechallenge.
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Juárez-Rodríguez, María Dolores, Jiseon Yang, Rebin Kader, Praveen Alamuri, Roy Curtiss, and Josephine E. Clark-Curtiss. "Live Attenuated Salmonella Vaccines Displaying Regulated Delayed Lysis and Delayed Antigen Synthesis To Confer Protection against Mycobacterium tuberculosis." Infection and Immunity 80, no. 2 (December 5, 2011): 815–31. http://dx.doi.org/10.1128/iai.05526-11.
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ABSTRACTLive recombinant attenuatedSalmonellavaccine (RASV) strains have great potential to induce protective immunity againstMycobacterium tuberculosisby deliveringM. tuberculosisantigens. Recently, we reported that, in orally immunized mice, RASV strains delivering theM. tuberculosisearly secreted antigenic target 6-kDa (ESAT-6) protein and culture filtrate protein 10 (CFP-10) antigens via theSalmonellatype III secretion system (SopE amino-terminal region residues 1 to 80 with two copies of ESAT-6 and one copy of CFP-10 [SopENt80-E2C]) afforded protection against aerosol challenge withM. tuberculosis. Here, we constructed and evaluated an improvedSalmonellavaccine againstM. tuberculosis. We constructed translational fusions for the synthesis of two copies of ESAT-6 plus CFP-10 fused to the OmpC signal sequence (OmpCSS-E2C) and amino acids 44 to 338 of antigen 85A (Ag85A294) flanked by the signal sequence (SS) and C-terminal peptide (CT) of β-lactamase (BlaSS-Ag85A294-BlaCT) to enable delivery via theSalmonellatype II secretion system. The genes expressing these proteins were cloned as an operon transcribed from Ptrcinto isogenic Asd+/MurA+pYA3681 lysis vector derivatives with different replication origins (pBR, p15A, pSC101), resulting in pYA4890, pYA4891, and pYA4892 for SopENt80-E2C/Ag85A294synthesis and pYA4893 and pYA4894 for OmpCSS-E2C/Ag85A294synthesis. Mice orally immunized with the RASV χ11021 strain engineered to display regulated delayed lysis and regulated delayed antigen synthesisin vivoand harboring pYA4891, pYA4893, or pYA4894 elicited significantly greater humoral and cellular immune responses, and the RASV χ11021 strain afforded a greater degree of protection againstM. tuberculosisaerosol challenge in mice than RASVs harboring any other Asd+/MurA+lysis plasmid and immunization withM. bovisBCG, demonstrating that RASV strains displaying regulated delayed lysis with delayed antigen synthesis resulted in highly immunogenic delivery vectors for oral vaccination againstM. tuberculosisinfection.
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Biddle, F. G., S. A. Eden, J. S. Rossler, and B. A. Eales. "Sex and death in the mouse: genetically delayed reproduction and senescence." Genome 40, no. 2 (April 1, 1997): 229–35. http://dx.doi.org/10.1139/g97-032.
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A mammalian model of genetically postponed aging would be an important tool to test not only different mechanisms of aging but also the predictive value of various biomarkers of the aging process. Under conventional conditions, the historical strains of the laboratory mouse produce their first litter between 9 and 13 weeks of age and have a median time of death in their 2nd year. Our POSCH-2 strain, which was derived from wild-caught Mus musculus domesticus, produces its first litter in the current breeding generations at approximately 47 weeks of age and continues to breed throughout its 2nd and into its 3rd year of life. The aging curve of POSCH-2 has not yet been determined for economic reasons. Late onset of breeding is a characteristic of both females and males, but sexual maturity is more reliably assessed in females. The later breeding phenotype of POSCH-2 is genetically recessive to early breeding of the C57BL/6J historical laboratory strain and, since POSCH-2 females can be induced to ovulate at 8 weeks of age (but pregnancy does not result), the signal rather than the ovarian receptor to ovulate may be delayed. The genetically delayed reproduction and potentially longer life of the POSCH-2 strain appears to be a new trait in the mouse. The strain may be a useful mammalian model for aging studies and for the evaluation of antagonistic pleiotropy as a genetic model for the evolution of aging.Key words: delayed reproduction, senescence, aging, genetics, mouse.
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Montealegre, Constanza, and Peter H. Graham. "Preference in the nodulation ofPhaseolus vulgariscv. RAB39. II. Effect of delayed inoculation or low cell representation in the inoculant on nodule occupancy byRhizobium tropiciUMR1899." Canadian Journal of Microbiology 42, no. 8 (August 1, 1996): 844–50. http://dx.doi.org/10.1139/m96-106.
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Common bean (Phaseolus vulgaris L.) is a traditional crop in much of Latin America, where it is often planted into soils containing numerous, sometimes ineffective, indigenous rhizobia. The presence of these indigenous organisms can limit response to inoculation. Because of this, we have sought bean cultivars that will nodulate preferentially with the inoculant strain, and have previously reported on the preference between the bean cultivar RAB39 and strains of Rhizobium tropici. We have detailed this interaction using the inoculant-quality strain UMR1899. In the present study the root tip marking (RTM) technique was used to demonstrate that this preference in nodulation was evident, even when inoculation with UMR1899 was delayed up to 8 relative to that with Rhizobium etli UMR1632. In contrast to studies with other legumes, roots of RAB39 were not predisposed to nodulate with UMR1632, even though preexposed to this strain for considerable periods of time. The presence of UMR1899 actually reduced nodulation by UMR1632 substantially, even when inoculation with UMR1899 was significantly delayed. When UMR1899 and UMR1632 were applied to separate halves of a split-root system, the number of nodules on the side receiving UMR1632 was less than for the half root inoculated with UMR1899, but the differences were not significant. This suggests that the preference response is not systemic but requires proximity between the strains involved. UMR1899 produced more than 50% of the nodules even when the ratio of UMR1632:UMR1899 in the inoculant was 10:1. The results are further evidence of a stable and marked preference of RAB39 for UMR1899, which warrants a more detailed study at the field level.Key words: Phaseolus vulgaris L., common bean, delayed inoculation, strain preference, cell proportions.
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Luong, Thanh T., Mei G. Lei, and Chia Y. Lee. "Staphylococcus aureus Rbf Activates Biofilm Formation In Vitro and Promotes Virulence in a Murine Foreign Body Infection Model." Infection and Immunity 77, no. 1 (October 27, 2008): 335–40. http://dx.doi.org/10.1128/iai.00872-08.
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ABSTRACT We previously identified Rbf as an activator for biofilm formation on polystyrene surfaces in Staphylococcus aureus strain 8325-4. However, strain 8325-4 contains genetic mutations that may affect biofilm formation. To extend the observation to other strains, we used strain Newman, a weak biofilm producer, and strain UAMS-1, an osteomyelitis clinical strain, in this study. We found that mutations in the chromosomal rbf gene did not affect biofilm formation on polystyrene surfaces in these strains, but transformants of these strains carrying a multiple-copy plasmid containing the rbf gene formed stronger biofilms than the wild-type strains and the mutant strains. Using the flow cell method, we found that the chromosomal mutation in the rbf gene delayed biofilm formation, whereas strains with a plasmid containing the rbf gene accelerated biofilm formation in strains Newman and UAMS-1. These results led us to conclude that rbf is an activator of biofilm formation in different strains of S. aureus, although the degree of activation varies among strains. In a murine model of foreign body infection, the rbf mutations in strain Newman, but not in strain UAMS-1, reduced the bacterial survival rate in catheter lumen. However, UAMS-1 carrying multiple copies of rbf in a plasmid increased the bacterial survival rate. The animal studies therefore suggest that Rbf has a role in S. aureus virulence.
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Abriouel, Hikmate, Mercedes Maqueda, Antonio Gálvez, Manuel Martínez-Bueno, and Eva Valdivia. "Inhibition of Bacterial Growth, Enterotoxin Production, and Spore Outgrowth in Strains of Bacillus cereus by Bacteriocin AS-48." Applied and Environmental Microbiology 68, no. 3 (March 2002): 1473–77. http://dx.doi.org/10.1128/aem.68.3.1473-1477.2002.
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ABSTRACT Bacteriocin AS-48 showed high bactericidal activity for mesophilic and psychrotrophic strains of Bacillus cereus over a broad pH range. AS-48 inhibition of the enterotoxin-producing strain LWL1 was enhanced by sodium nitrite, sodium lactate, and sodium chloride. The latter also enhanced AS-48 activity against strain CECT 131. Bacterial growth and enterotoxin production by strain LWL1 were completely inhibited at bacteriocin concentrations of 7.5 μg/ml. At subinhibitory bacteriocin concentrations, enterotoxin production decreased markedly and sporulation was delayed. Intact spores were resistant to AS-48 but became gradually sensitive to AS-48 during the course of germination.
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Aili, A., J. M. Torrenti, J. P. Sellin, J. F. Barthelemy, and M. Vandamme. "On the long-term delayed strain of concrete structures." Cement and Concrete Research 165 (March 2023): 107086. http://dx.doi.org/10.1016/j.cemconres.2022.107086.
Full textDissertations / Theses on the topic "Delayed strain"
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Filho, Antonio Tito Paladino. "Avaliação de fibrose miocárdica pelo strain, comparado ao achado de realce tardio da ressonância magnética cardíaca, em pacientes portadores de cardiopatia chagásica crônica." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/98/98131/tde-07102016-082606/.
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Desde o primeiro relato a Doença de Chagas permanece endêmica na América Latina com 18 milhões de pessoas cronicamente infectadas e, aproximadamente, 200.000 novos casos por ano. Doença parasitária causada por Trypanosoma cruzi, tem como transmissor \"natural\" da doença um inseto hematófago, o Reduris (barbeiro). Este inseto se torna infectado ao ingerir o sangue de um animal ou indivíduo infectado com o Trypanosoma cruzi. O contágio ocorre basicamente nas áreas rurais nas quais o homem, frequentemente, está em contato com hospedeiros e vetores ao destruir a mata nativa. Apesar da infecção geralmente ocorrer nos primeiros anos de vida, os pacientes infectados podem manifestar os sinais e sintomas da cardiopatia chagásica até 20 anos mais tarde. O custo propriamente dito e o sofrimento humano representados pela Doença de Chagas são grandes. Medicamentos, internações hospitalares frequentes e tratamento com dispositivos de alto custo (ex: marcapasso/ cardiodesfibrilador). Com quadro clínico insidioso, os pacientes podem apresentar insuficiência cardíaca franca, eventos tromboembólicos, arritmias ventriculares, dor torácica atípica e morte súbita. Seu diagnóstico baseia-se em epidemiologia positiva, anamnese, exame físico, alterações eletrocardiográficas, radiológicas e testes sorológicos. O envolvimento cardíaco é a principal causa de morte, sendo que a fisiopatologia e a evolução clínica da doença não são completamente compreendidas e a estratificação de risco permanece um desafio. A presença de disfunção miocárdica associada ou não à doença arterial aterosclerótica vem acompanhada de áreas de fibrose miocárdica e tem se mostrado como importante fator de pior prognóstico. A Ressonância Magnética Cardíaca (RMC) é um método já consagrado na detecção de fibrose miocárdica pela técnica de realce tardio (RT). Os objetivos dessa tese são: 1-Correlacionar o strain miocárdico nos segmentos do ventrículo esquerdo com as áreas de realce tardio detectadas na Ressonância Magnética Cardíaca, 2- Correlacionar o strain global do ventrículo esquerdo avaliado pela técnica de Speckle Tracking com a extensão de fibrose (numero de segmentos) avaliada pela Ressonância Magnética Cardíaca; 3- Comparar a Fração de ejeção avaliada pelo Ecocardiograma bidimensional e a Ressonância Magnética Cardíaca em pacientes com cardiopatia chagásica crônica; 4- Avaliar se existe relação entre a fração de ejeção avaliada pelo ecocardiograma bidimensional e a extensão de fibrose (número de segmentos) pela Ressonância Cardíaca. Foram selecionados 31 pacientes com o diagnóstico confirmado de Doença de Chagas. 27 pacientes que respeitaram os critérios de inclusão e exclusão, e que assinaram o termo de consentimento livre e esclarecido realizaram Ressonância Magnética Cardíaca com a técnica de realce tardio. De todos os pacientes selecionados, 27 completaram o protocolo da RMC e realizaram em sequencia o Ecocardiograma transtorácico para avaliar o strain miocárdico (speckle tracking) em intervalo máximo de 5 dias. Todos que completaram o protocolo não apresentaram efeitos adversos e os exames foram considerados interpretáveis. Para calcular a amostra de pacientes necessária, os cálculos foram feitos pela estatística de teste t, com distribuição t de Student, para comparação entre duas médias, com poder de teste de 80% e nível de significância de 5%, o que resultou numa estimativa de tamanho mínimo de amostra de 22 lesões por grupo (44 lesões) para que seja possível identificar diferenças significativas em todas as regiões numa amostra com medidas de mesmo comportamento que as observadas em Yajima et al e Jitsuo Higaki et al. Com isso, a amostra mínima seria de 22 pacientes. Para avaliar a concordância entre variáveis quantitativas, utilizou-se o coeficiente de concordância de Lin com intervalo de confiança (IC) 95% estimado segundo método Bootstrap. O coeficiente de concordância de Lin (Rc) combinada precisão e acurácia para determinar se observações desviam-se significativamente da linha de perfeita concordância (linha de 45 graus com origem no 0 dos eixos x e y). O coeficiente de Kappa de Cohen com IC 95% foi utilizado em analises de concordância para variáveis categóricas. Valores de p foram calculados utilizando-se método exato. Os critérios de Landis & Koch foram utilizados na interpretação dos coeficientes de concordância, assim definidos: (a) quase-perfeita, para valores de 0,81 a 1,00; (b) substancial, para valores de 0,61 a 0,80; (c) moderada, para valores entre 0,41 e 0,60; (d) regular, para valores entre 0,21 e 0,40; (d) discreta, para valores de 0 a 0,20. As estimações de intervalos de confiança 95% via bootstrap basearam-se em 1000 replicações. Estimativas de sensibilidade, especificidade, valores preditivo positivo e negativo com IC95% foram determinados. Variáveis quantitativas foram comparadas entre 2 grupos independentes utilizando-se testes não-paramétrico de Mann-Whitney com métodos exatos de cálculo do valor-p. Variáveis quantitativas comparadas com Mann-Whitney foram descritas com mediana e intervalo interquartil. Dado o reduzido tamanho de amostra, analise de regressão logística binaria univariada foi conduzida utilizando método exato. Para covariável quantitativa foi testada, a suposição de linearidade com o log-odds no modelo de regressão logística através da construção de \"Smoothed Scatter Plots\". Quando suposição não foi satisfeita, covariável originalmente quantitativa foi dicotomizadas segundo a mediana da distribuição. Odds ratios e seus respectivos intervalos de confiança 95% foram estimados. Analises de correlação entre variáveis quantitativas foram conduzidas utilizando-se coeficiente de correlação de Spearman(rho)(com IC95%). Forte correlação foi definida como |rho| >=0.70; correlação moderada para 0.5 <= |rho| <0.7 ; correlação fraca a moderada para 0.3<= |rho| <0.5; e fraca para |rho| <0.3. Normalidade foi avaliada com a inspeção visual de histogramas e aplicação do teste de normalidade Shapiro-Wilks. Todos os valores de p apresentados são do tipo bilateral: p < 0.05 e 0.05Since the first report, Chaga\'s disease remains endemic in Latin America with 18 million chronically infected people and approximately 200,000 new cases per year. Parasitic disease caused by Trypanosoma cruzi, is \"natural\" transmitter disease of a hematophagous insect, the Reduris (barber). This insect becomes infected by ingesting blood of an animal or individual infected with Trypanosoma cruzi. The infection occurs primarily in rural areas where men often are in touch with hosts and vectors by destroying the native forest. Despite the infection usually occurs early in life, infected patients may exhibit signs and symptoms of Chagas disease 20 years later. The cost itself and human suffering represented by Chagas disease are a public issue. Medication, frequent hospitalization and treatment with costly devices (eg pacemaker / defibrillator) are frequently necessary. With insidious clinical signs and symptons, patients may present with heart failure, thromboembolic events, ventricular arrhythmias, atypical chest pain and sudden death. Its diagnosis is based on positive epidemiology, history, physical examination, electrocardiographic, radiological and serological changes. Cardiac involvement is the leading cause of death, and the pathophysiology and clinical course of the disease are not fully understood and the risk stratification remains a challenge. The presence of myocardial dysfunction with or without atherosclerotic arterial disease is accompanied by myocardial fibrosis areas and has been an important factor of poor prognosis. Cardiac Magnetic Resonance (CMR) is a method already established in the detection of myocardial fibrosis by delayed gadolinium enhancement technique (DGE). The objectives of this thesis are: 1-To correlate myocardial strain in left ventricular segments with areas of late enhancement detected in Cardiac Magnetic Resonance, 2- correlate the global left ventricular strain measured by Speckle Tracking technique with fibrosis extension (number of segments) evaluated by Cardiac Magnetic Resonance; 3- Compare the ejection fraction assessed by Two-dimensional echocardiography and cardiac Magnetic Resonance in patients with chronic cardiac Chagas\' disease; 4- To assess whether there is a relationship between the ejection fraction assessed by two-dimensional echocardiography and fibrosis extension (number of segments) by CMR. We selected 31 patients with confirmed diagnosis of Chagas\' disease. 27 patients who complied with the inclusion and exclusion criteria, and who signed the informed consent , performed Cardiac Magnetic Resonance with late gadolinium enhancement (DGE) technique. Of all the selected patients, 27 completed the RMC protocol and were in sequence directed to the transthoracic echocardiogram to assess myocardial strain (speckle tracking) in maximum interval of 5 days. Everyone who completed the protocol showed no adverse effects and the tests were considered interpretable. To calculate the sample required patients, we used the test statistic t, with t Student distribution for comparison between two averages, with the power to test 80% and 5% significance level, which resulted in an estimate minimum sample of 22 injuries per group size (44 injuries) so you can identify significant differences in all regions in a sample with the same measures of behavior than those observed in Yajima et al and Jitsuo Higaki et al. Thus, the minimum sample size would be 22 patients. To evaluate the correlation between quantitative variables, we used the Lin\'s concordance coefficient (1,2) with a confidence interval (CI) 95% estimated second method Bootstrap (4). The correlation coefficient Lin (Rc) combines precision and accuracy to determine if observations deviate significantly from perfect correlation line (45 degree line with origin 0 of the x and y axes). Cohen\'s kappa coefficient with 95% (3) was used for analysis of agreement for categorical variables. P values were calculated using the exact method. The Landis and Koch criteria (5) were used in the interpretation of correlation coefficients defined as follows: (a) quasi-perfect for values 0.81 to 1.00; (b) substantial amounts of 0.61 to the 0.80; (c) Moderate to values between 0.41 and 0.60; (d) regular, to between 0.21 and 0.40; (d) mild to values from 0 to 0.20. The estimation of 95% confidence intervals by bootstrap based on 1000 replicates. Quantitative variables were compared between two independent groups using non-parametric Mann-Whitney test with exact methods of calculating the p-value. (6-8) Quantitative variables compared with Mann-Whitney were described as median and interquartile range. Given the small sample size, regression analysis univariate binary logistic regression was conducted using exact method (9-11). For quantitative covariate was tested, the linearity assumption with the log-odds in the logistic regression model by building \"Smoothed Scatter Plots\". (9) When assumption was not met, originally quantitative covariate was dichotomized according to the median of the distribution. Odds ratios and their 95% confidence intervals were estimated. All significance probabilities (p values) presented are the bilateral type and values less than 0.05 considered statistically significant. The R (R Foundation, Vienna, Austria) software was used for statistical analysis of data. In order to measure the correlation between the results of both tests in the study were calculated sensitivity, specificity, positive predictive value and negative predictive value considering the CMR as the gold standard. Results: Of the 27 study patients have a average age of 53.1 + - 7.0 years and median of 54 years. 08 (29.7%) men and 19 (70.3%) women. The average ejection fraction by echocardiography was 55.1 + - 14.7%, and by Cardiac Magnetic Resonance was 55.8 + - 13.4%. The total number of evaluated segments was 453 (98.7%), with no interpretation performed in only 6 segments (1.3%) on echocardiography, a total of 459 segments. Delayed enhancement by Cardiac Magnetic Ressonance was found in 61 segments analyzed. In the order \"side\" 86 segmets registered an altered strain. As the gold standard the delayed enhancement in the MRC, compared to segment studied segment. We take into account the literature describing the prevalence of fibrosis in patients with chronic Chagas\' heart disease of approximately 40%. With this data we obtained a sensitivity of 95%, specificity 91%, positive predictive value of 88.6% and a negative predictive value of 96.6%. Correlating the Global Longitudinal Strain (SGL) and extent (number of segments with delayed enhancement by CMR) of fibrosis in this study, no difference was observed in the number of segments of medians in the CMR compared between Strain Global Longitudinal groups - Normal x changed (p = 0.287, exact Mann-Whitney). Using as an ejection fraction of the left ventricle limits > = 55% as normal and < 55% changed, compared to the extent of fibrose- number of segments- (delayed enhancement) by CMR. There was a marginally significant difference when comparing the median number of segments with delayed enhancement on CMR between the 2 groups (p = 0.064). ¹based on exact Mann-Whitney test. We also compared the ejection fraction of the left ventricle by CMR and transthoracic echocardiography using the Simpson method. At a significance level of 5% (Lin coefficient), there was an almost perfect correlation between LVEF by Cardiac Magnetic Resonance and LVEF by using transthoracic echocardiography in both the Simpson method. (Rc = 0.9335 95% CI 0878-0957; N = 27)
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Xing, Yan, and Yan Xing. "Investigation of Rock Mass Stability around Underground Excavations in an Underground Mine in USA." Diss., The University of Arizona, 2017. http://hdl.handle.net/10150/625648.
Full textAbstract:
Underground excavations break the balance of the initial stress field and cause stress redistributions in the surrounding rock masses. Problems normally arise as the stress exceeds the rock mass strength. In addition, the rock mass contains preexisting defects, such as the fissures, fractures, joints, faults, shear zones, dikes, etc., which could significantly weaken the rock mass strength and make the rock mass behavior complicated. The stability of underground excavations is of great importance to an operating mine project since it ensures the safety of the working environment and the successful ore exploration.
Due to the complex geological conditions and engineering disturbances, the assessment of rock mass stability for a practical engineering problem is extremely challenging and difficult, which needs to be solved by the modern numerical methods. In this dissertation, the rock mass stability around tunnels in an underground mine in the USA was investigated by performing three-dimensional modeling using the 3DEC 3-Dimensional Distinct Element Code. Comprehensive stress analyses were respectively carried out on a preliminary model and a more advanced model.
In the preliminary study, the built model contains the inclined lithologies, a non-persistent fault, and a convoluted tunnel system. The geomechanical property values used for the rock masses and discontinuities in the numerical model were estimated using the available geotechnical information and the experience of the research group. The Mohr-Coulomb and strain softening constitutive relations were prescribed for the rock masses; the coulomb slip joint model was assigned for the discontinuities. The influence of the boundary conditions, block constitutive models, horizontal in situ stress and rock support system on the tunnel stability was investigated. The rock mass behavior was quantified using the results of stress, displacement, and yielded zones around the tunnels. It showed that the roller boundary conditions resulted in slightly different but comparable results with the combined boundary conditions (roller and stress combined) where K0 equals to 0.4 or 0.5. Whereas the in-situ stress field for a complex geological system can only be obtained by applying proper boundary stresses and then by performing stress analysis. The softening behavior of the rock masses caused more deformations and yielded zones around the tunnels; the rock masses around the tunnels were observed to reach the residual strength values, which can be treated as failed areas. In addition, the M-C and s-s rock masses reacted differently as the K0 value changed. At K0=1.0, the tunnels seemed to be the most stable; K0=1.5, however, provided the worst scenario with roof and floor problems. With respect to the effectiveness of the support system, a large amount of the bonds of the supports was failing, thus, the deformations and yielded zones around the tunnels were slightly improved. Finally, comparisons between the numerical modeling results and the field measurements implied the applicability of strain softening behavior and a K0 value between 0.5 and 1.0 for the mine.
Based on the specific geological, geotechnical, and construction information, a numerical model incorporating accurate features was developed. It includes a non-planar, weak interlayer, the persistent and non-persistent faults, and the open and backfilled excavations. The mechanical property values used for the rock masses and faults were estimated based on the laboratory test results of the intact rock and smooth joints. The strain softening behavior was specified for the rock masses belonging to the average quality, and the rock masses that reached residual strengths were assumed to be failing. The linear relations between the fault stiffnesses and normal stress were described using the continuously yielding joint model. To simulate the mine construction process in the field, the sequential excavation, backfilling, and supporting procedures were numerically implemented; additionally, a novel routine was applied to account for the delayed installation of the supports. Results showed that the tunnels close to the fault and the backfilled area were less stable. Most of the displacements around the tunnels occurred within a distance of zero to 2 or 3 m from the tunnel surface. The varying K0 value caused great changes in the rock mass behavior and the shear behavior of the major fault; significant instability of the tunnels was triggered by the high horizontal in situ stress. Parametric studies on the rock mass condition, rock mass residual strengths, and fault property values showed that the tunnel stability was more sensitive to the former two factors than the last one. A systematic investigation was conducted to evaluate the current rock supports installed at the mine where the increasing stress relaxation was incorporated. The deformations and of the failure zone thicknesses around the tunnels were reduced up to 8% and 20% after applying the supports instantaneously, and the reductions were improved by the delayed installation of supports. Additionally, the safety of supports was evaluated by the bond shear and bolt tensile failures, which was also improved with incorporation of delayed supporting. It was found that the current rock supports are insufficient in length, bond and tensile strengths. Therefore, a stronger support system was suggested. The stronger supports worked better in stabilizing the tunnels. Based on the deformations and failures of the rock masses, the length of the bolts on walls was suggested to be 4-5 m. At the end, the horizontal convergence strain predicted by the numerical simulations were calculated at two locations where the tape extensometers were installed. Good agreements with the field measurements were obtained for the cases that have the average rock mass properties and K0 values in the range 0.5-1.25.
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Mastroeni, Pietro. "Immunity to Salmonella, role of : antibodies, T-cells, TNF#alpha# and INF#gamma# in resistance to infection and in delayed type hypersensitivity in mice immunised with aroA S. typhimurium SL3261 live attenuated vaccine strain." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320407.
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Kleine, Alexandra. "Modélisation numérique du comportement des ouvrages souterrains par une approche viscoplastique." Thesis, Vandoeuvre-les-Nancy, INPL, 2007. http://www.theses.fr/2007INPL083N/document.
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La nature est complexe et c’est en toute modestie que les ingénieurs doivent chercher à prédire le comportement des ouvrages dans le sous-sol. La réalisation de projets industriels dans le domaine souterrain, à forts enjeux économiques et sociaux (traversées alpines, stockage de déchets nucléaires), nécessite d’évoluer vers une meilleure compréhension des mécanismes comportementaux des ouvrages à concevoir. Cette amélioration passe par une meilleure représentativité physique des mécanismes macroscopiques et par la mise à disposition d’outils de prédiction adaptés aux attentes et aux besoins des ingénieurs. Les outils de calculs développés dans ce travail s’inscrivent dans cette volonté de rapprocher les attentes de l’industrie et les connaissances liées à la rhéologie des géomatériaux. Ces développements ont ainsi débouché sur la proposition d’un modèle de comportement mécanique, adapté aux roches peu fissurées et assimilables à des milieux continus, intégrant, en particulier, l’effet du temps. Fil conducteur de cette étude, la problématique du sujet de thèse concerne précisément la prise en compte du comportement différé des massifs rocheux dans les modélisations et ses conséquences sur les ouvrages souterrains.Fondé sur des concepts physiques de référence, définis à différentes échelles (macro/méso/micro), le modèle rhéologique développé est transcrit dans un formalisme mathématique dans le but d’être mis en oeuvre numériquement.Les applications numériques proposées s’inscrivent principalement dans le contexte du stockage des déchets radioactifs. Elles concernent deux configurations d’ouvrages rigoureusement différentes : l’excavation du laboratoire souterrain canadien de l’AECL, dans le granite du Lac du Bonnet et le creusement de la galerie GMR du laboratoire de Bure (Meuse/Haute-Marne) dans l’argilite de l’Est. Dans les deux cas, l’utilisation du modèle a permis de mettre en évidence l’apport de la prise en compte du comportement différé sur la représentativité des prédictions numériques du comportement à court, moyen et long termes des ouvrages souterrainsNature is complex and must be approached in total modesty by engineers seeking to predict the behavior of underground openings. The engineering of industrial projects in underground situations, with high economic and social stakes (Alpine mountain crossings, nuclear waste repository), mean striving to gain better understanding of the behavioral mechanisms of the openings to be designed. This improvement necessarily involves better physical representativeness of macroscopic mechanisms and the provision of prediction tools suited to the expectations and needs of the engineers. The calculation tools developed in this work is in step with this concern for satisfying industrial needs and developing knowledges related to the rheology of geomaterials. These developments led to the proposing of a mechanical constitutive model, suited to lightly fissured rocks, comparable to continuous media, while integrating more particularly the effect of time.Thread of this study, the problematics ensued from the subject of the thesis is precisely about the rock mass delayed behavior in numerical modeling and its consequences on underground openings design.Based on physical concepts of reference, defined in several scales (macro/meso/micro), the developed constitutive model is translated in a mathematical formalism in order to be numerically implemented.Numerical applications presented as illustrations fall mainly within the framework of nuclear waste repository problems. They concern two very different configurations of underground openings: the AECL’s underground canadian laboratory, excavated in the Lac du Bonnet granite, and the GMR gallery of Bure’s laboratory (Meuse/Haute-Marne), dug in argillaceous rock.In this two cases, this constitutive model use highlights the gains to be obtained from allowing for delayed behavior regarding the accuracy of numerical tunnel behavior predictions in the short, medium and long terms
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Le, Roy Robert. "Déformations instantanées et différées des bétons à hautes performances." Phd thesis, Marne-la-vallée, ENPC, 1995. http://www.theses.fr/1995ENPC9534.
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On présente ici deux types de modélisations, ainsi que de nombreuses données expérimentales, portant sur les déformations des bétons et en particulier celles des bétons à hautes performances. La première a pour but de prévoir les amplitudes des déformations instantanées, de retrait endogène et de fluage propre, en fonction de la formulation. On utilise pour cela une approche par homogénéisation, en adaptant le modèle bisphère de Hashin au calcul du module du béton. La démarche de modélisation, fondée sur la prise en compte de la compacité réelle du squelette granulaire, aboutit à une géométrie trisphère. On fait le choix, après l'avoir justifié, de fixer les coefficients de Poisson à un cinquième. Puis, on applique le modèle trisphère au calcul des amplitudes de fluage propre et de retrait endogène. Les paramètres principaux de formulation (rapports eau sur ciment, fumée de silice sur ciment, proportion granulaire, classe du ciment) sont pris en compte. L'approche appliquée au fluage est confortée par un calcul viscoélastique linéaire. Dans la deuxième approche, on propose un modèle simplifié, de type réglementaire, pour le calcul des déformations des bétons à hautes performances en fonction du temps, et d'un nombre limité de paramètres. Les apports principaux de la modélisation concernent la prise en compte de l'autodessiccation, de la maturité et de la résistance du matériau au moment du chargement. Le modèle a été validé d'après de nombreuses données, et pour des bétons de maturités très variables au chargement, variant de seize heures à plus de deux ans. Elaboré dans le cadre de l'Association Française pour la Recherche et l'Etude des Matériaux et des Structures (AFREM), le modèle est proposé comme annexe au règlement français de béton précontraint (BPEL), pour les bétons couvrant la gamme B60-B80This thesis proposes two types of modelling, together with a long series of experimental date, for the instantaneaous and time-dependent strains of high performance concrete. The first model deals with instantaneous, autogenous shrinkage and basic creep deformations of high performance concrete with respect to mix-design parameters. To the end, a homogenization approach based on Hashin’s spheres model for the modulus, is adopted and modified to take into account the effective maximum packing density of the aggregates. This leads to a three-sphere model. After justification, the Poisson’s ratio of each phase is set at a constant value of 0,2. This model is consequently applied to calculate the long-term amplitude of autogenous shrinkage and basic-creep. The creep results obtained are compared with visco-elastic calculation, which allows the adopted approach to be confirm. The main mix-design parameters are taken into account (water/cement ratio, silica fume/cement ratio, aggregate concentration, maximum packing density of the agregate, cement strength). The second research part deals with a simplified model for design code purposes. It allows the calculation of high performance concrete strains as a function of time, and a limited number of parameters. In particular it accounts for the self-dessication, the maturity and the strength of the concrete at the loading time. This model was validated against extensive experimental data, covering the marurity rang from sixteen hours to two years. The model was established within the framework of the French Structures and Materials Research Association (AFREM) and is proposed in addition to the French Prestressed Concrete French Code (BPEL) for concrete covering the strength range from 40 to 80 Mega-Pascals
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Carlson, Mark. "Post-Exercise Responses During Treatment Delays do not Affect the Physiological Responses to Cooling in Cold Water in Hyperthermic Individuals." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/24392.
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Victims of exertional heat stroke (EHS) in whom treatment is delayed have higher rates of multi-organ failure and a greater number of fatalities. Death related to EHS is preventable, through immediate treatment via cold-water immersion (CWI). To date little is known about the influence of treatment delays on core cooling following EHS. Thus we sought to examine the effects of treatment delays on cardiovascular and thermal responses prior to, during, and following CWI treatment in individuals with exercise-induced hyperthermia.
Our findings demonstrate that treatment delays resulted in a sustained level of hyperthermia and cardiovascular strain that significantly increased the time an individual is at risk to the potential lethal effects of EHS. Moreover, we report that cold water immersion treatment is powerful enough to overcome the adverse effects of treatment delays and rapidly reduce core temperatures while facilitating the re-establishment of blood pressure towards normal resting levels.
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Molony, Anna. "The application of fibre Bragg grating networks as strain sensors and as phased array antenna true time delay elements." Thesis, Aston University, 1996. http://publications.aston.ac.uk/15355/.
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The fabrication of in-fibre Bragg gratings, and the application of arrays of such gratings as strain sensors and as true time delay elements for the control of phased array antennas is reported. Chirped period Bragg gratings were produced using the fibre deformation fabrication technique, with chirps of between 2.9nm and 17.3nm achieved. Arrays of 5mm and 2mm long uniform period Bragg gratings were fabricated using the inscription method, for use as true time delay elements,dissimilar wavefronts and their spectral characteristics recorded. The uniform period grating arrays were used to create minimum time delays of 9.09ps, 19.02ps and 31ps; making them suitable for controlling phased array antennas operating at RF frequencies of up to 3GHz, with 10° phase resolution. Four 4mm long chirped gratings were produced using the dissimilar wavefronts fabrication method, having chirps of 7nm, 12nm, 20nm and 30nm, and were used to create time delays of between 0.3ps and 59ps. Hence they are suitable for controlling phased array antennas at RF frequencies of up to 48GHz. The application of in fibre Bragg gratings as strain sensors within smart structure materials was investigated, with their sensitivity to applied strain and compression measured for both embedded and surface mounted uniform period and fibre Fabry-Perot filter gratings. A fibre Bragg grating sensor demultiplexing scheme based on a liquid crystal filled Fabry-Perot etalon tuneable transmission filter was proposed, successfully constructed and fully characterised. Three characteristics of the LCFP etalon were found to pose operational limitations to its application in a Bragg grating sensor system; most significantly, the resonance peak wavelength was highly (-2,77nm/°C) temperature dependent. Several methods for minimising this temperature sensitivity were investigated, but enjoyed only limited success. It was therefore concluded that this type (E7 filled) of LCFP etalon is unsuitable for use as a Bragg grating sensor demultiplexing element.
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Porras, Pérez Antonio Reyes. "Multi-cue image integration for cardiac tissue characterization." Doctoral thesis, Universitat Pompeu Fabra, 2015. http://hdl.handle.net/10803/296796.
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Una caracterización precisa y completa del tejido cardíaco es esencial para el diagnóstico y tratamiento de problemas cardíacos. Para caracterizar la función cardíaca desde diferentes perspectivas, en la práctica clínica, se adquieren grandes cantidades de datos de distinta naturaleza sobre un mismo paciente, proporcionando información útil para la evaluación del corazón. Aunque los distintos datos obtenidos de cada paciente se suelen analizar por separado para evaluar la función cardíaca desde diferentes perspectivas, la combinación efectiva de esta información heterogénea podría ser útil para tener una mejor visión de la anatomía y la función cardíaca. El objetivo principal de esta tesis es el desarrollo de métodos para integrar imágenes e información de distinta naturaleza para una caracterización del tejido cardíaco más completa y precisa.An accurate and complete cardiac tissue characterization is essential to diagnose and treat heart problems. To characterize cardiac function from different perspectives, large amounts of data of different nature from the same patient are acquired in clinical practice, providing information that is useful for heart assessment. Although the different data obtained from each patient are often analyzed separately to assess cardiac function from different perspectives, the effective combination of this heterogeneous information may be useful for a better insight into heart anatomy and function. The main objective of this thesis is to develop methods to integrate images and information of different nature for a more complete and accurate cardiac tissue characterization.
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Leung, Pah Hang Thierry. "Les bétons bas pH : comportements initial et différé sous contraintes externes." Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30139/document.
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Dans le cadre du stockage des déchets radioactifs en couches géologiques profondes (argilite du Callovo-Oxfordien), des bétons à faible alcalinité et à faible chaleur d'hydratation référencés "bas pH " ont été élaborés. L'utilisation de ces types de béton permet de limiter la dégradation des propriétés confinantes du matériau argileux type bentonite. Deux bétons bas pH à base de liants ternaires ont étudiés : un composé de ciment, fumée de silice et cendres volantes (TCV) et l'autre composé de ciment, fumée de silice et laitier moulu de haut fourneau (TL). L'objectif de l'étude est d'analyser le comportement de ces matériaux pour s'assurer : d'une mise en œuvre correcte à l'échelle industrielle, d'une bonne tenue chimique et mécanique dans le temps et d'un confinement performant. Le programme expérimental comprend la caractérisation physico-chimique et mécanique de ces matériaux à forte teneur en additions et est couplé à de la modélisation dans le but, in fine, de disposer d'outils permettant de prédire leur comportement au sein de l'ouvrage. Les résultats montrent qu'un cobroyage des constituants du liant permet d'améliorer la réactivité du liant et de s'assurer d'une bonne robustesse des formules de béton. La condition essentielle de l'obtention d'un pH de leur solution interstitielle de 11 est assurée dès 28 jours. Les bétons peuvent être considérés à faible chaleur d'hydratation du fait des échauffements rencontrés à court terme. A long terme, de hautes performances mécaniques, de faibles coefficients de perméabilité et de diffusion sont obtenus sur ces matériaux. Les modélisations de l'hydratation, de l'évolution de propriétés mécaniques, de l'endommagement, des déformations différées et des transferts hydriques ont été abordées. Le modèle d'hydratation utilisé a été adapté aux liants ternaires en prenant en compte les phénomènes de nucléation des additions sur l'hydratation du ciment. Pour les autres modèles, l'acquisition des mesures expérimentales a permis de fournir les données d'entrée pour leur utilisation et de vérifier leur validité sur des liants fortement dilués. Tous ces travaux permettent au final d'envisager sereinement la modélisation et la prédiction du comportement des structures réalisées en béton bas pHIn the context of the radioactive wastes disposal in deep geological repository of clay, low-alkalinity and low heat of hydration concretes referenced "low pH " were designed. The degradation of the properties of the clay can be limited by using these types of concrete. Two types of low pH binder were chosen for this research: the first one is comprised of cement, silica fume and fly ash (TCV) and the other one is comprised of cement, silica fume and slag (TL). The objective of this research is to comprehend the behavior of these concrete in order to ensure the well-placing of the fresh concrete at an industrial scale and good mechanical performances, chemical stability and confining properties. The experimental program focuses on a physico-chemical and mechanical characterization of these recent materials with high pozzolanic addition content. The experimental data are then modeled for the purpose of having a tool that, in the end, is able to predict the behavior of the low pH concretes within the structure. The results show that grinding altogether the three constituents improves the reactivity of the binder and allows a good reproducibility of the low pH design. The most important criterion which is a pH of the interstitial solution below 11 is met at 28 days. The heat measurements at early age show that the low pH concretes are low heat of hydration concretes as well. In the long run, high mechanical performances, low permeabilities and diffusivities were obtained on these materials. The modeling of the hydration, evolution of mechanical properties, damage, creep and hydric transfers is also covered in this thesis. The model of hydration was adjusted to match the hydration of ternary binders by taking into account the effects of the additions such as the heterogeneous nucleation, on the hydration of the cement. As for the other models, the experimental results were used as data input to validate the models on binders with high replacement rates. Ultimately, this work allows us to contemplate serenely the modeling and the prediction of the behavior of structure made of low pH concretes
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Khokhar, Muhammad Irfan. "Optimisation of concrete mix design with high content of mineral additions: effect on microstructure, hydration and shrinkage." Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209985.
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The cement being used in the construction industry is the result of a chemical processlinked to the decarbonation of limestone conducted at high temperature and results in a
significant release of CO2. This thesis is part of the project EcoBéton (Green concrete) funded
by the French National Research Agency (ANR), with a purpose to show the feasibility of
high substitution of cement by mineral additions such as blast furnaces slag, fly ash and
limestone fillers. Generally for high percentages of replacements, the early age strength is
lower than Portland cement concrete. To cope with this problem, an optimisation method for
mix design of concrete using Bolomey’s law has been proposed. Following the encouraging
results obtained from mortar, a series of tests on concretes with different substitution
percentages were carried out to validate the optimisation method. To meet the requirements of
the construction industry related to performance of concrete at early age, which determine
their durability, a complete experimental study was carried out. Standard tests for the
characterization of the mechanical properties (compressive strength, tensile strength, and
setting) allowed to validate the choice of mix design on the basis of equivalent performance.
We focused on the hydration process to understand the evolution of the mechanical
properties. Setting time measurement by ultrasound device at different temperatures (10°C,
20°C and 30°C) showed that ground granulated blast furnace slag (GGBFS) and fly ash
delayed the setting process, while use of limestone filler may accelerate this process.
Calorimetric studies over mortars and concretes made possible to calculate the activation
energy of the different mixtures and a decrease in heat of hydration of concretes with mineral
additions was observed which is beneficial for use in mega projects of concrete. Scanning
Electron Microscopy observations and thermal analysis have given enough information about
the hydration process. It was observed that the hydration products are similar for different
concrete mixtures, but the time of their appearance and quantity in the cement matrix varies
for each concrete mix.
Last part of the thesis was dedicated to the study of main types of shrinkage. First of all,
deformations measured were correlated to hydration, capillary depression and porosity
evolution. Results allowed concluding that the use of mineral additions has an actual effect on
the plastic shrinkage behaviour, but its impact is not proportional to the percentage of
additions. Substitution of cement by the additions seems to have a marked influence on the
kinetics of the shrinkage without any effect on its long term amplitude. The study of
restrained shrinkage under drying conditions by means of ring tests showed that concretes
with high percentage of slag addition seem more prone to cracking than the Portland cement
concretes.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Books on the topic "Delayed strain"
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Kjaer, Michael, and Abigail Mackey. Muscle. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199533909.003.0002.
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Skeletal muscle is not only essential for human movement and performance, but is unfortunately also a common site for acute injuries related to physical activity and sports. The influence of exercise on skeletal muscle represents a wide range all the way from (i) physiological adaptation with regard to metabolism, morphology, and contractile properties, through (ii) physiological development of muscle hypertrophy, to (iii) pathological/physiological responses to heavy unaccustomed exercise with associated delayed onset of muscle soreness, and ending with (iv) muscle injury caused by either strain or contusion (and seldom laceration) trauma. In the present chapter we will focus on the muscle responses to acute stimuli that cause muscle injury of minor or larger magnitude, and the ensuing recovery....
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Bomberger, E. Douglas. Implosions. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190872311.003.0011.
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The refusal of the Boston Symphony Orchestra management to program “The Star-Spangled Banner” in Providence, Rhode Island, on 30 October led to nationwide outrage against Karl Muck in early November. Anti-German sentiment ran high as concerts by Muck’s orchestra were cancelled in Baltimore and concerts by Fritz Kreisler were banned in Pittsburgh. The Metropolitan Opera dropped all German operas from its repertoire. Both Walter Damrosch and Ernestine Schumann-Heink went to great lengths to prove their patriotism, but Schumann-Heink broke under the strain and withdrew from the stage for six weeks. The Fifteenth Regiment had orders to ship out to France but was delayed twice in November. This month was a significant turning point in American attitudes, as jazz became increasingly popular and European music and musicians were viewed with suspicion and disdain.
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Smith, Rebecca. Anthrax. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199976805.003.0062.
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Anthrax spores are found in the soil in many parts of the world and usually cause disease in grazing animals. Human disease is typically seen in farmers, ranchers, and workers handling animal carcasses, hides, hair, and bones. In biologic warfare or terrorism, aerosolization of the spores has been considered as an effective route of mass dissemination. Clinical presentation depends on the route of exposure: cutaneous, ingestion, inhalation (or Woolsorter’s disease). Personal protective equipment and patient decontamination are important before addressing a potential exposure. Mass casualty incidents will likely cause a strain on resources and appropriate triage will be crucial. Cardiopulmonary monitoring may not be available for all patients and should be reserved for patients with a high suspicion for inhalational anthrax. The duration of antibiotic therapy for all suspected bioterrorism attacks is 60 days in order to adequately cover for possible delayed development of inhalational anthrax.
Book chapters on the topic "Delayed strain"
1
Allali, Karam. "On Time-Delayed Two-Strain Epidemic Model with General Incidence Rates and Therapy." In Trends in Biomathematics: Modeling Epidemiological, Neuronal, and Social Dynamics, 233–51. Cham: Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-33050-6_14.
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Conte, Alessio, Roberto Grossi, Giulia Punzi, and Takeaki Uno. "Polynomial-Delay Enumeration of Maximal Common Subsequences." In String Processing and Information Retrieval, 189–202. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-32686-9_14.
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Conte, Alessio, Roberto Grossi, Andrea Marino, Takeaki Uno, and Luca Versari. "Listing Maximal Independent Sets with Minimal Space and Bounded Delay." In String Processing and Information Retrieval, 144–60. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-67428-5_13.
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Bilham, Roger. "Delays in the Onset Times of Near-Surface Strain and Tilt Precursors to Earthquakes." In Maurice Ewing Series, 411–21. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/me004p0411.
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Lie, T. A., G. J. Nijland, and S. H. Waluyo. "Competition between Nodulating and Non-Nodulating Rhizobium Strains: Delay of Nodulation." In Physiological Limitations and the Genetic Improvement of Symbiotic Nitrogen Fixation, 127–36. Dordrecht: Springer Netherlands, 1988. http://dx.doi.org/10.1007/978-94-009-1401-8_14.
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Lee, Jong K. "Delay Differential Equation Approach to the Stress-Strain Behavior of Crystalline Materials during Hot Working." In The Mechanical Behavior of Materials X, 17–20. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-440-5.17.
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Porrino, Jack, and Alvin R. Wyatt. "Muscle Injury." In Musculoskeletal Imaging Volume 1, edited by Mihra S. Taljanovic and Tyson S. Chadaz, 134–36. Oxford University Press, 2019. http://dx.doi.org/10.1093/med/9780190938161.003.0028.
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Chapter 28 reviews soft tissue injury and muscle injury. Muscle injury may be the result of contusion, laceration, strain, or delayed-onset muscle soreness. Although radiography and CT have a limited role in the diagnosis and management of muscle injury, both US and MRI can be used to provide detailed information pertaining to the location, extent, and severity of the injury. Treatment of muscle injury is dependent on the severity of injury. With respect to muscle strain, most grade I and II injuries are managed conservatively, while grade III injuries may require early surgical intervention to avoid permanent retraction and scar formation.
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Bristow, Jennie. "Ambivalent adulthood." In Stop Mugging Grandma, 190–210. Yale University Press, 2019. http://dx.doi.org/10.12987/yale/9780300236835.003.0009.
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This chapter reveals a new and increasingly prominent strain of Millennial angst — the problem of growing up itself — and the ways in which the Boomers have allegedly made that so much harder to do. The Baby Boomers are blamed not only for creating the problem of rising house prices and unstable employment, but for refusing to understand their children's pain. Given the scattergun vitriol that blames the Boomers for everything, it is perhaps not surprising that delayed adulthood should be framed as their fault too. But there is a curious tension between the thwarted desire to grow up that Millennial angst tries to exude, and the content of this aspiration. Millennials may rail against being ‘trapped in kidulthood’ — but it is far from clear whether they actually want to escape it.
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Banham, Tony. "1941: Pre–Pacific War Australia." In Reduced to a Symbolical Scale. Hong Kong University Press, 2017. http://dx.doi.org/10.5790/hongkong/9789888390878.003.0005.
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Chapter Four observes the evacuees’ environment as they fought to be allowed to return to Hong Kong and made the largely unassisted transition from pre-evacuation Colony to the difficulties (real and perceived) of life in Australia. They now had the social position of refugees. The eighteen months of separation before the Japanese attack meant families were immediately under strain - at the Hong Kong and Australian ends. The pressure on evacuated families was greater than on those not evacuated, added to by the continuing sense of injustice that many of the latter had deliberately evaded evacuation. The Hong Kong evacuees’ experience is contextualised through comparison with American civilians in the Philippines who were not evacuated and would eventually fare far worse. The vain hope for repatriation to Hong Kong delayed acclimatisation to Australia for many – though now more families realised that they could regain control of their destinies, by the evacuees themselves leaving Australia or by husbands who had been left behind leaving Hong Kong. Meanwhile, demonstrations and petitions calling for repatriation of the evacuees to Hong Kong grew to a crescendo.
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Romero, Jorge, Andrea Natale, Ricardo Avendano, Mario Garcia, and Luigi Di Biase. "Prevention of sudden cardiac death in ischaemic cardiomyopathy." In ESC CardioMed, edited by Gerhard Hindricks, 2333–37. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198784906.003.0552.
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Sudden cardiac death (SCD) is a major health problem in both the United States and worldwide. There is considerable controversy regarding the optimal time after acute myocardial infarction for risk stratification as well as the ideal time to place an implantable cardioverter defibrillator for primary prevention for SCD. Several parameters have been considered and tested for risk stratification of SCD after acute myocardial infarction. However, the only criterion that is currently being implemented is the left ventricular ejection fraction (LVEF). There are different imaging methods to measure LVEF, including echocardiography, cardiovascular magnetic resonance (CMR) imaging, nuclear scintigraphy, and angiography. When compared, these methods have shown modest correlation among them with up to 10% differences in LVEF and wide standard deviations (average 10%), which raises questions about their reliability to make decisions about primary prevention strategies for these patients. Moreover, LVEF assessment after acute myocardial infarction may be significantly affected by transient myocardial stunning and patients with a LVEF greater than 35% are not exempt from ventricular arrhythmias. Despite previous studies showing a considerably higher reduction in cardiac and total mortality when electrophysiological study is performed, current guidelines for prevention of SCD do not recommend electrophysiological study very strongly. CMR imaging has gained popularity for risk stratification of SCD. Delayed gadolinium enhancement has been proven to be useful in the identification of myocardial scar due to acute or chronic myocardial infarction. In the authors’ opinion, electrophysiological study and CMR imaging and probably strain echocardiography as well as cardiac iodine-123 metaiodobenzylguanidine will eventually play more important roles in risk stratification of patients with ischaemic cardiomyopathy based on the data published to date.
Conference papers on the topic "Delayed strain"
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Kelley, Christopher R., and Jeffrey L. Kauffman. "Effect of Switch Delays on Piezoelectric-Based Semi-Active Vibration Reduction Techniques." In ASME 2015 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/smasis2015-9051.
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Piezoelectric transducers have been used for semi-active vibration reduction in structures by altering the stiffness state and dissipating electrical energy. Common approaches include state switching, synchronized switch damping on a resistor (SSDS), and synchronized switch damping on an inductor (SSDI). Each of these methods requires four switches per vibration cycle, so any delay in the switch from the ideal moment could have a significant effect on the vibration reduction. An experimental investigation into the effect of switch delays on these techniques reveals that the abrupt change in piezoelectric voltage from the switch has the effect of a step input on the structure, which may excite higher order modes and increase the peak strain. This non-ideal switching of boundary conditions has implications towards the design and performance of these state switching techniques. Switching at the peak is classically considered the ideal switch time, but the influence of the switch on the local strain may actually result in a higher peak strain for the structure than with a delayed switch. This paper will examine switch times that lead and lag the ideal case for state switching, SSDS, and SSDI to quantify the level of vibration reduction achieved under non-ideal peak sensing.
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Berveiller, S., M. Kemdehoundja, E. Patoor, D. Bouscaud, and M. R. Berrahmoune. "Influence of pre-strain and carbon content on delayed cracking phenomenon in unstable austenitic steels." In ESOMAT 2009 - 8th European Symposium on Martensitic Transformations. Les Ulis, France: EDP Sciences, 2009. http://dx.doi.org/10.1051/esomat/200906005.
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Nishiyama, M., H. Igawa, T. Kasai, and N. Watanabe. "Distributed dynamic strain measurement using long-gauge FBG and DTR3interrogator based on delayed transmission/reflection ratiometric reflectometry." In Asia Pacific Optical Sensors Conference 2013, edited by Minghong Yang, Dongning Wang, and Yun-Jiang Rao. SPIE, 2013. http://dx.doi.org/10.1117/12.2030872.
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Koizumi, Kengo, Yoshihiro Kanda, Akihiro Fujii, and Hitoshi Murai. "High-speed distributed strain measurement using brillouin optical time-domain reflectometry based-on self-delayed heterodyne detection." In 2015 European Conference on Optical Communication (ECOC). IEEE, 2015. http://dx.doi.org/10.1109/ecoc.2015.7341700.
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Aumuller, John J., Zihui Xia, and Feng Ju. "Application of Elastic-Plastic Methods to Delayed Coker Drum Design." In ASME 2011 Pressure Vessels and Piping Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/pvp2011-57275.
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Coke drums are pressure vessels that are used in oil sands and conventional refinery processing industries for the thermal cracking of reduced bitumen to recover additional, saleable gas and liquid product streams. The drums are constructed to the requirements of ASME VIII Division 1 although they are in a low cycle thermal-mechanical service environment. Recent practice has been to introduce design by analysis considerations from ASME VIII Division 2 even though service temperatures of the actual equipment exceed the design limits of the Code. In this paper, simplified elastic-plastic analysis models are developed for assessment of the stress and strain levels in coke drums during specific operational phases. One model is applied for determination of the local stress caused by differences in the coefficients of thermal expansion between the clad liner and base materials. Because clad construction is used throughout the vessel, the impact is extensive. Consideration is given to the general stresses induced by the cyclical, progressive dilation and contraction action of the drum shell caused by axial thermal gradients. Another model estimates hot and cold spot formation and the development of localized stress / strain distributions in coke drums. The resulting thermal stresses include the local stress from suppression of differential expansion between clad and base material, thermal bending stresses and local thermal stresses from hot and cold spot formation. It is found that the evaluation of these loads on drum cracking aligns with industry survey results. Better understanding of these loads has impact on materials selection and fabrication procedures for new drums and repair of existing drums. Operational considerations can also be identified to help improve drum reliability.
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Yaqub, Muhammad Arslan, Stijn Matthys, and Christoph Czaderski. "Potential of memory steel reinforcement for shear strengthening of concrete bridge girders with I-sections." In IABSE Symposium, Prague 2022: Challenges for Existing and Oncoming Structures. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2022. http://dx.doi.org/10.2749/prague.2022.1180.
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<p>This study was carried out to access the performance of near surface mounted (NSM) memory steel reinforcement for shear strengthening of concrete girders with I-sections. Specially designed/strengthened concrete I-sections were tested in tension and the bond behaviour of memory steel was observed and reported as failure mode, load displacement and strain variation. It has been demonstrated that the memory steel reinforcement has a great potential for active shear strengthening of concrete girders with I-section. The activation of memory steel apply prestress on the I-section that delays the cracking and increases the ultimate failure load. The delayed shear cracking will consequently retain the aggregate interlock mechanism that is the main component of shear strength. Besides the additional strength of the external reinforcement, the yielding of internal stirrups is also delayed that further retains the intrinsic shear strength.</p><p>The results reported in this paper are part of a wider study to investigate various shear strengthening configurations for precast prestressed I-girders using memory steel reinforcement and fibre reinforced polymers (FRPs).</p>
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Aumuller, John J., Toshiya Yamamoto, and Zengtao Chen. "Further Considerations for the Determination of Service Life for Delayed Coker Drums." In ASME 2018 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/pvp2018-84005.
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Delayed coker drums are unique in hydrocarbon processing facilities in that estimating their true design and service life has been problematic. Generally, pressure containing equipment in these facilities is designed using the notion of design life based on required pressure thickness and corrosion allowance considerations. Hence, pressure containing equipment is routinely monitored by facility inspectors for wall thickness. Although many analysts have ascribed coke drum failure to “thermal stress cycling”, the difficulty posed by the operation of coke drums results in an inability to measure or calculate the magnitude of the thermo-mechanical “stresses” and the actual number of significant exposures, that is, cycles causing fatigue damage. As well, the use of Code construction practices has been generally misapplied, for this specific equipment, as the practices are intended to define a safe design life rather than a service life. Indirect measures of service life based on shell bulge severity have fallen from favor by being ineffective. A trend to use a strain index method is somewhat more appealing but is based on static load and monotonic material property considerations rather than those properties indicative of thermal cyclic operation. Recent work has shown that thermo-mechanical strain cycling can be characterized quantitatively and used to determine a cyclic service life for both undamaged and damaged coke drums. This paper discusses some of the engineering specifics to generate a high probability estimate of coke drum fatigue service life for a new drum, a damaged-stable drum, drums with weld overlay and for drums exhibiting incremental damage.
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Bouquet, Pascal J. P., and Albert H. Cardon. "Application of the Electronic Speckle Pattern Interferometry (ESPI) Technique for the Localisation Analysis of Damage Development in Composites." In ASME 2002 International Mechanical Engineering Congress and Exposition. ASMEDC, 2002. http://dx.doi.org/10.1115/imece2002-33448.
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The analysis of the long-term behaviour of polymer matrix composites has to be performed for their stiffness evolution and for their strength changes. Long fiber reinforced polymer matrix composites exhibit an anisotropic viscoelastic-viscoplastic behaviour. The non-linear viscoelastic constitutive equations proposed by R. Schapery [1], with a viscoplastic correction are able to analyse the long-term stiffness evolution on the basis of some short-term creep and creep-recovery tests. For the strength analysis it is possible to consider some delayed failure approach as the end of a viscoelastic-viscoplastic behaviour. The experimental follow-up of the creep evolution till rupture needs a full field technique in order to have a complete view of the strain field and the evolution of this field where the damage initiation and development transforms the homogeneous strain distribution in an heterogeneous one. The ESPI technique shows clearly the location of the damage initiation and allows us to follow the damage development. Examples of the ESPI technique on graphite epoxy specimen will be presented and the results in relation to the delayed failure analysis will be discussed.
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Nyman, Douglas J., Charles H. Dowding, and Lewis L. Oriard. "Evaluation of Close-In Blasting Effects on Welded Steel Pipelines." In 2008 7th International Pipeline Conference. ASMEDC, 2008. http://dx.doi.org/10.1115/ipc2008-64400.
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Occasionally, it is necessary to perform blasting close to buried, welded steel pipelines to excavate foundations or roadway cuts, conduct mining operations, or to construct an adjacent pipeline trench. The primary hazards associated with blasting near pipelines include permanent rock mass displacement owing to delayed gas pressures and ground strains from wave propagation (compressive, shear and surface waves). Current pipeline standards do not address these limitations for blasting in proximity to buried pipelines. Existing methodology is often applied quite conservatively in the form of permissible ground particle velocity thereby limiting ground strain, which leads to increased costs for the party conducting the blasting and/or the pipeline owner who must provide pipeline protection. This paper presents methodology and guidelines for the evaluation and protection of buried pipelines subjected to the effects of blasting. The examples given in the paper represent a departure from the normal practice of specifying blasting restrictions on buried pipelines, because they are based on higher peak particle velocity limits than suggested by other researchers and currently adopted by a number of pipeline companies. General recommendations are provided for evaluating the strains induced into buried pipelines and avoiding the effects of mass movement of rock due to delayed gas pressure. The general goal for this paper is to produce methodology and guidelines that are equally applicable and realistic for both the pipeline owner and the party conducting the blasting; however, they should not be considered to be recommendations for any specific future project.
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Saboori, Parisa, Shahab Mansoor-Baghaei, and Ali M. Sadegh. "Evaluation of Head Injury Criteria Under Different Impact Loading." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-65125.
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The Head Injury Criterion (HIC) has been employed as a measure of traumatic brain injury arising from an impact involving linear acceleration. Some investigators have been reported the shortcomings of the HIC regarding the angular accelerations, head mass and the precise threshold of injury level [1, 2]. In this study the effect of acceleration curves, as a frontal impact, and the HIC values on the strain in the brain was critically analyzed. Specifically in this paper, the strains in the brain for three sets of acceleration pulses, where the peak of the curve takes place early or later (advanced or delayed) during the pulse time, were investigated. The results of this study indicate that for two different acceleration pulses, with the same peak value, duration and the same HIC values the strains in the brain are different. Therefore there is a need for further research leading to better criteria or modification of the HIC as it relates to the Traumatic Brain Injury (TBI).
Reports on the topic "Delayed strain"
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Swankie, Martin, and Andrews. L52012 Mechanisms and Kinetics of Crack Growth in Areas of Mechanical Damage. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 2005. http://dx.doi.org/10.55274/r0011185.
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The project was primarily experimental in nature. It has utilised small scale specimen and ring expansion testing rather than full scale vessel tests to investigate the mechanisms responsible for time-delayed failures. The aim was to perform a series of laboratory experiments to investigate the influence of pre-strain and cyclic frequency on the behaviour of pipeline steels subject to low cycle fatigue and sustained loads. The initial experimental programme consisted of tensile tests and fatigue crack growth tests including tensile dwell periods, carried out on pre-strained and non pre-strained pipe material. Ring expansion tests were then carried out on specimens with dent-gouge defects with varying dent depths. These tests included hold periods at maximum pressure intended to produce time dependent crack growth. Small scale testing to determine isochronous stress-strain curves at ambient temperature was also carried out for one material.
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Chell and Crouch. HIX1IYS Nonlinear Harmonic Based Mechanical Damage Severity for Delayed Failures in Pipelines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 2008. http://dx.doi.org/10.55274/r0011186.
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The objectives of the current work are to (1) provide an assessment of the capabilities of the nonlinear harmonic (NLH) method to detect gouged dents in pressurized pipelines; (2) rank the severity of the detected defects against delayed failure; (3) provide information related to the remaining lives of detected defects when fatigue damage from cyclic pressure changes is the time-dependent mechanism controlling delayed failure; and (4) transfer the developed NLHbased defect severity criteria to an inline inspection vendor, Tuboscope Pipeline Services. An ancillary objective is to assess the capability of NLH probes to detect strain anomalies produced by crack-like flaws in the outside surfaces of pressurized pipes. In this project, the assessment of the capabilities of NLH to detect and rank the severity of defects is based on the analysis of results obtained from NLH measurements performed over the inside surfaces of pressurized pipe sections containing gouged dents subjected to cyclic pressure changes (fatigue loading) that eventually resulted in failure (leakage) at defects, and NLH scans of statically pressurized pipes containing crack-like machined notches.
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Ahn, Changrim. Two Aspects of One Loop Structure: Unitarity Delay in the Standard Model and Modular Invariance in String Theory. Office of Scientific and Technical Information (OSTI), August 1989. http://dx.doi.org/10.2172/1454052.
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Ahn, C. Two aspects of one loop structure: Unitarity delay in the Standard Model and modular invariance in string theory. Office of Scientific and Technical Information (OSTI), August 1989. http://dx.doi.org/10.2172/5580440.
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Mitchell, Brian G., Amir Neori, Charles Yarish, D. Allen Davis, Tzachi Samocha, and Lior Guttman. The use of aquaculture effluents in spray culture for the production of high protein macroalgae for shrimp aqua-feeds. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7597934.bard.
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The FAO has projected a doubling in world demand for seafood during the 21 ed from aquaculture of marine fish and shrimps fed primarily on fishmeal-based aquafeeds. However, current practices of high intensity monoculture of shrimp in coastal ponds and fish in offshore pens have been strongly criticized as being ecologically and socially unsustainable. This view derives from un- checked eutrophication of coastal marine ecosystems from fish farm effluents, and the destruction of coastal estuarine ecosystems by shrimp farm constructions, plus aquaculture’s reliance on wild-caught small fish - which are excellent food for humans, but instead are rendered into fishmeal and fish oil for formulating aquafeeds. Fishmeal-sparing and waste- reduction aquafeeds can only delay the time when fed aquaculture product are priced out of affordability for most consumers. Additionally, replacement of fishmeal protein and fish oil by terrestrial plant sources such as soybean meal and oil directly raises food costs for human communities in developing nations. New formulations incorporating sustainably-produced marine algal proteins and oils are growing in acceptance as viable and practical alternatives. This BARD collaborative research project investigated a sustainable water-sparing spray/drip culture method for producing high-protein marine macrophyte meals for incorporation into marine shrimp and fish diets. The spray culture work was conducted at laboratory-scale in the USA (UCSD-SIO) using selected Gracilariaand Ulvastrains isolated and supplied by UCONN, and outdoors at pilot-scale in Israel (IOLR-NCM) using local strains of Ulvasp., and nitrogen/phosphorus-enriched fish farm effluent to fertilize the spray cultures and produce seaweed biomass and meals containing up to 27% raw protein (dry weight content). Auburn University (USA) in consultation with TAMUS (USA) used the IOLR meals to formulate diets and conduct marine shrimp feeding trials, which resulted in mixed outcomes, indicating further work was needed to chemically identify and remove anti-nutritional elements present in the IOLR-produced seaweed meals.
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Jacobsen, Nils. Linjebussens vekst og fall i den voksende byen: en studie av bybussenes geografiske kvalitet Stavanger – Sandnes 1920 – 2010. University of Stavanger, November 2019. http://dx.doi.org/10.31265/usps.244.
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Linear city bus services are facing increased challenges from city growth. Increased number of inhabitants on increasing acres of built-up areas, makes it demanding to maintain adequate bus services within reasonable catchment areas. Number of departures per hour give a partial description of the bus service quality. Number of departures give reference to the time aspect of bus service quality, but say nothing about the geographical aspect. What part of the entire line network is within reach of direct bus service when frequencies are limited? To address the geographical aspect of bus service quality, the term network ratio is introduced. The term Network Ratio (NR) signifies what part of the entire line network is within reach of direct bus service to or from a certain place in the network. Network Ratio is given as a mathematical term whereby direct bus lines are calculated as a percentage of the entire network. The character and development of Network Ratio in a specific city is illustrated through an analysis of the urban growth of line network and built-up areas in the twin cities of Stavanger and Sandnes. The analysis is covering the period 1920 – 2000 in intervals of 20 years from the first bus lines were established in the urban area. Year 2010 is also included due to major changes implemented right after the turn of the millennium. Development show there is a close relation between bus network and built-up areas. When areas are being built, bus lines follow. The initial fase 1920 – 40 with extensive development of bus lines combined with some areal growth, is followed by a fase of consolidation 1940 – 60. The latter period is characterized by moderate areal growth, extended lines reducing network ratios, and increasing frequencies on the best bus lines. Extensive areal growth in the following period 1960 – 80, implies increased number of bus lines. As a consequence network ratios as well as frequencies are falling in the entire network. In 1960 certain lines had developed as much as 6 departures per hour, while maximum bus line frequency in 1980 has diminished to 2. New bus service development is introduced in the following period between 1980 and 2000. Numerous bus companies are united, and a more comprehensive planning of bus services are applied. The number of bus lines is stabilized at about 40, the fall in network ratio is reduced, and certain lines develop 4 departures per hour. Parallell to the bus development, growth of built-up areas is slowing down due to increased urban renewal with higher densities within built-up areas. In the period 2000 – 2010 new efforts are given to the development of bus services. Development of Network Ratio takes a new direction: The length of network links with high NR is increasing, while links with very low NR are diminishing. Number of bus lines is decreasing, and by 2010 almost 50% of the bus lines are served with 4 departures or more. Passenger comfort is improved in buses as well as on bus stops, and low floor buses are introduced to ease accessibility. Bus service quality is further developed after 2010. Digital services are introduced including digital ticketing, bus service information and real-time information on internet. In addition real-time information is presented at high frequency bus stops through visual screen and auditory speaker. Inside the buses name of next stop is given on screen and through loudspeaker. Further development of the bus services, should include improved Network Ratios in the entire network, as well as increased frequencies on major bus corridors. The latter is a task not only for the bus service planners, but just as well for the city planners and politicians in collaboration with the developers implementing urban density and allocation of important destinations. A last, but not least, objective for bus service development will be to improve punctuality and total travel time. Today a considerable proportion of city bus services are delayed in car traffic congestions. This is occurring especially on main streets and during rush hours. A set of different solutions are needed to address this question: 1. Dedicated bus streets (including car access to limited addresses) 2. Bus lines through local streets in concentrated housing, office and shopping areas. 3. Dedicated bus lane on main streets where possible. 4. Car traffic regulations on main streets without space for extra bus lane. As an overall vision, we need to cultivate the word of Flemming Larsen: urban growth as pearls on a string, as shown in fig. 13 and fig. 14.
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Dudoit, Alain. European common data spaces: a structuring initiative that is both necessary and adaptable to Canada. CIRANO, November 2023. http://dx.doi.org/10.54932/skhp9567.
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Faced with the acceleration of the digital economy, the governance and effective sharing of data have become fundamental issues for public policy at all levels of jurisdictions and in all areas of human activity. This paper reviews the initiatives and challenges associated with data governance, with a particular focus on the European Common Data Spaces (ECDS) and their direct relevance to the Canadian context. It explores the inherent complexity of data governance, which must reconcile sector-specificities with more horizontal governance principles. In doing so, it highlights the importance of strategic and coordinated action to maximize the social and economic benefits of data. The Burgundy Report, published by CIRANO in July 2023, calls for the creation of a common data space in the Great Lakes-St. Lawrence Strategic Trade Corridor by 2030. This proposal builds in particular on three separate policy reports published in 2022 by the National Supply Chain Task Force, the Council of Ministers Responsible for Transportation and Highway Safety (COMT) and the House of Commons Standing Committee on Transportation, Infrastructure and Communities. The findings and recommendations of these reports raise fundamental questions that are central to the critical issues of governance, organizational culture, execution capacity, public and private stakeholder engagement, and data underutilization within the Canadian government machinery strained by years of delay and exacerbated by recent disruptions related to anticipated climate disasters. The creation of a common data space is envisaged as a structuring investment in Canada's essential infrastructure for intermodal transport and the supply chain. This working paper on European Common Data Spaces (ECDS) extends the synthesis and recommendations published last July 2023 by providing an operational analysis of the transformative initiative currently underway within the European Union (EU). This major policy development stems from the 2020 European Data Strategy and seeks to establish twelve common data spaces in strategic sectors, including mobility and transport. The document is divided into three main parts. The first part provides an overview of data-related public policies in Canada and the EU between 2018 and 2023. The second part focuses on the implications and lessons learned from the impact assessment supporting the adoption of data governance legislation by the European institutions. This directive establishes a regulatory framework for the creation of common data spaces in the EU. The third section discusses the current deployment of ECDSs, highlighting key milestones and ongoing processes. The paper highlights notable similarities between the EU and Canada in the identification of data issues and the formulation of public policy objectives. It also highlights differences in optimizing data sharing between jurisdictions and stakeholders. A fundamental difference between these two strategic partners is the absence of an effective and sustained pooling of resources within the Canadian intergovernmental machinery in pursuit of common objectives in the face of major shared challenges such as data accessibility and sharing. This situation is in stark contrast to the EU's groundbreaking deployment of the ECDS in pursuit of identical objectives of positioning itself as a world leader in the data economy. This lack of consideration, let alone joint action, by Canada's intergovernmental machinery to implement a common data strategy in Canada is damaging. To be effective, the Canadian response must be agile, results-oriented, and interoperable across jurisdictions. The rigorous management, responsible use, and organized sharing of data within and between jurisdictions are crucial to addressing the complex challenges and major risks facing Canada. Neither the federal nor provincial governments are currently well positioned to treat data as a shared strategic asset. The resolution of regulatory, legal, and technical obstacles to data exchange between jurisdictions and organizations cannot be achieved without the creation of a common data space. This can only be achieved by combining the necessary tools and infrastructures, and by addressing issues of trust, for example by means of common rules drawn up for this purpose. “The barriers that prevent the establishment of robust health data sharing systems are not technical, but rather fundamentally political and cultural.”