Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-03-27T22:34:27Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_PrevalenciaAnticorposAntivirus.pdf: 46169016 bytes, checksum: e6d4bbf300e991af7eb9406198b1e9e3 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-04-02T17:13:10Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_PrevalenciaAnticorposAntivirus.pdf: 46169016 bytes, checksum: e6d4bbf300e991af7eb9406198b1e9e3 (MD5) / Made available in DSpace on 2013-04-02T17:13:10Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_PrevalenciaAnticorposAntivirus.pdf: 46169016 bytes, checksum: e6d4bbf300e991af7eb9406198b1e9e3 (MD5) Previous issue date: 2002 / A avaliação da prevalência de anticorpos contra o vírus da Hepatite A foi realizada no período de setembro a dezembro de 2000, em 185 escolares de níveis sócio-econômicos distintos, na faixa etária entre seis e quinze anos, em duas escolas no município de Porto Velho, Rondônia, utilizando teste imunoenzimático comercial (DiaSorin) para detecção de anticorpos anti-VHA Totais e IgM. Foram avaliados 90 escolares de nível sócio-econômico médio e alto, procedentes de Escola Privada, e 95 de baixo nível sócio-econômico, de Escola Pública. Dos 90 escolares da Escola Privada, 45 (50%) apresentaram positividade ao teste para detecção de anticorpos anti-VHA Totais e deste, 4 (8,9%) foram soropositivos ao anti-VHA IgM, enquanto na Escola Pública, dos 95 estudantes, 90 (94,7%) apresentaram anticorpos anti-VHA Totais e destes, apenas 1 (1,1%) apresentou anticorpos anti-VHA IgM (p< 0,05). As faixas etárias entre 12 e 14 anos na Escola Privada, e 8 e 10 anos na Escola Pública, apresentaram maior prevalência de anticorpos anti-VHA. Não houve diferença significativa de prevalência de anti-VHA entre os sexos, nos dois grupos estudados (p>0,05). Fatores como renda familiar, destino dos dejetos domiciliares e qualidade de água consumida também foram estudados e relacionados à prevalência de anti-VHA, apresentando diferenças significativas entre os grupos. Os resultados deste estudo mostraram que a HVA é endêmica na região, e que, medidas como melhoria nas condições sanitárias do município são necessárias para diminuir a propagação do VHA na população. / The evaluation of antibodies prevalence against the virus of Hepatitis A was perforrned frorn September to December of 2000, in one hundred eighty-five students from different socioeconomic levels, including an age group from six to fifteen years, in two schools in the municipal district of Porto Velho, Rondônia, through commercial ELlSA tests (Dia Sorin) for detection Total and IgM anti-HAV antibodies. It was evaluated ninety students of medium and high socioeconomic level came from private school and ninety-five students of low socioeconomic level came from public school. Forty-five of the ninety students (50%) from private school presented positiveness in the test for detection Total anti-HAV antibodies and four of them (8,9%) were positive to IgM anti-HAV too, while, in those came from public school, ninety students (94,7%) presented Total anti-HAV antibodies and only one of them (1,1%) was positive for IgM anti-HAV (p < 0,05). Factors, such as family income, destiny of domiciliation dejections and quality of consumed water were also studied and compared to the anti-HAV prevalence, presenting significant differences among the groups. The results of this study indicated that HAV is endemic in the area and that measures, such as improvement in the sanitary conditions of the municipal district, are necessary to reduce the propagation of HAV in the population.

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-04-02T19:34:47Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AvaliacaoExposicaoMercurio.pdf: 61451467 bytes, checksum: b2426f81d5945e08c3fc847ee39e216e (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-04-03T15:42:07Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AvaliacaoExposicaoMercurio.pdf: 61451467 bytes, checksum: b2426f81d5945e08c3fc847ee39e216e (MD5) / Made available in DSpace on 2013-04-03T15:42:07Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AvaliacaoExposicaoMercurio.pdf: 61451467 bytes, checksum: b2426f81d5945e08c3fc847ee39e216e (MD5) Previous issue date: 2002 / Foram estudados 100 binômios mãe-filho para verificação dos níveis de mercúrio total ao nascimento e o curso da exposição pós-natal sobre o desenvolvimento e crescimento de lactentes durante o primeiro semestre de vida, na cidade de Porto Velho. Para avaliação da exposição pré-natal, verificaram-se os níveis de mercúrio total ao nascimento, em amostras de cabelo da mãe e recém-nascido, placenta, cordão umbilical e sangue materno. Os recém-nascidos foram submetidos a exame clínico e físico de rotina. As mães responderam um questionário com informações relevantes na busca de fatores de risco para a acumulação mercurial ou que poderiam afetar o desenvolvimento neuropsicomotor de suas crianças. Para avaliação da exposição pós-natal, 86 crianças foram submetidas a uma avaliação física e do desenvolvimento neuropsicomotor na semana em que completavam seis meses de idade. O teste de Gesell foi o instrumento utilizado oara avaliação do desenvolvimento neuropsicomotor. Também foi coletada uma nova amostra de cabelo da criança para verificação dos níveis de mercúrio total aos seis meses de idade. Todos os dados foram analisados, comparados e submetidos a tratamento estatístico. Das vinte e três crianças (26%) que apresentaram atraso no desenvolvimento neuropsicomotor, 11 eram do sexo masculino e 12 eram do sexo feminino. Estas alterações foram correlacionadas com os níveis de mercúrio total no cabelo da criança ao nascer e aos seis meses de vida. Também foram encontradas correlações estatisticamente significantes entre o perímetro cefálico e os níveis de mercúrio total nas diversas amostras estudadas. / A cohort of 100 births was generated during november and december of 2000 in Porto Velho city. Mothers and her newborns had been examined to verify total mercury levels (TML) at the birth, and the course of posnatal exposure on development and growth of infants during the first semester of their extrauterine life. To evaluation of prenatal exposure TML at the birth in samples of maternal and newborns hair, placenta, umbilical coord, and maternal blood had been analyzed. The newborns underwent physical and clinical examination. Mothers answered a questionnare that included important infonnations about risk factors to mercury accumulation or that could affect the development and growth of her childrens. At six months of age, 86 of the infants underwent detailed phisical and neurobehavioral examination, to evaluate the postnatal exposure. Besides a new sample of infants hair had been analyzed to verify TML. All data had been analyzed, compared, and underwent statistical evaluation. 23 infants (26%) showed neurological developmental disturbance at six months of age. This had been correlated with TML in children hair as at birth as at 6 months of age. A statistically significant correlation was observed between the head circumference and TML' s in the several analyzed samples.

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-04-03T19:33:55Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_RiscoOcupacionalInfeccao.pdf: 45387683 bytes, checksum: 7d86a372a39d9f38204896611f4e3e88 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-04-09T13:54:51Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_RiscoOcupacionalInfeccao.pdf: 45387683 bytes, checksum: 7d86a372a39d9f38204896611f4e3e88 (MD5) / Made available in DSpace on 2013-04-09T13:54:51Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_RiscoOcupacionalInfeccao.pdf: 45387683 bytes, checksum: 7d86a372a39d9f38204896611f4e3e88 (MD5) Previous issue date: 2003 / A prevalência dos marcadores HBsAg e anti-HBc foi descrita em 168 indivíduos, distribuídos em três grupos: 88 usuárias do atendimento obstétrico, 61 profissionais de saúde do Centro Obstétrico (PAS/CO) e 19 funcionários administrativos (grupo controle), todos do Hospital de Base Dr. Ary Pinheiro de Porto Velho, capital de Rondônia. No período de novembro, dezembro de 2000 e janeiro de 2001 foram coletadas amostras de soros, para a detecção do VHB através do teste imunoenzimático (ELISA). A prevalência do HBsAg foi de 1.1% no grupo de usuárias obstétricas, nos PAS/CO 3,3% e no grupo controle 52,6%. Para o anti-HBc os resultados positivos foram 5,3% no grupo controle, 27,3% no grupo de usuárias e 42,6% no grupo dos PAS/CO. A estratificação por faixas etárias relacionada a sorologia positiva demonstrou que nos intervalos de 15 a 25 anos e 25 a 35 anos a prevalência do VHB foi maior, para os grupos de usuárias e controle, e; no grupo dos PAS/CO o intervalo de prevalência mais elevada foi de 45 a 55 anos. A elevada prevalência do VHB nas usuárias obstétricas pode ser fator de transmissão vertical. A taxa de positividade do grupo controle sugere à característica endêmica da população de Porto Velho. Fatores como o número de parceiros, o uso de preservativo e a escolaridade no grupo dos PAS/CO foram comparados com os resultados sorológicos para o VHB. O fluido orgânico e a via de exposição mais referidos nas ocorrências de contaminações pelos PAS/CO foram o sangue e a cutânea, 43% e 22% respectivamente. / The prevalence of HBsAg and anti-HBc was described in 168 individuals, distributed in 3 groups: 88 in-patients of the obstetric service, 61 health professionals of the obstetric center (PA CO) and 19 administrative employees (control group), all working at the Hospital de Base Dr. Ary Pinheiro - in Porto Velho, capital o fthe state of Rondônia. In the period of November and December of 2000 and January of 2001 serum samples were collected, for HBV detection using an enzyme immunoenzymatic assay (ELISA). The prevalence of the HBsAg was 1,1% of the obstetric patients, 3,3% in PAS/CO and 52,6% in the control group. For anti-HBc the positive results were 5,3% in the control group, 27,3% in the patient's group and 42,6% in the PAS/CO group. The study by age groups related to the positive serology, demonstrated that from 15 to 25 years and 25 to 35 years the prevalence of HBV was larger, for the patients and control, and in the groups of PAS/CO the higher prevalence was from 45 to 55 years. The high prevalence of HBV in the patient's way lead to a high prevalence of vertical transmission. The positive numbers of 1he control group is in agreement with the endemic characteristic of the population of Porto Velho. Factors as the number of sexual partners, the use of preservatives and the level of education in the PAS/CO group were compared with serological results for HBV. The organic fluid and the most referred exposure via of contamination or PAS/CO were the blood and cutaneous, 43% and 22% respectively.

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-04-09T20:27:36Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_PerfilEpidemiologicoPrevalencia.pdf: 52716306 bytes, checksum: 27f1b77c2773453579b329d92b3bd9f3 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-04-10T15:38:16Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_PerfilEpidemiologicoPrevalencia.pdf: 52716306 bytes, checksum: 27f1b77c2773453579b329d92b3bd9f3 (MD5) / Made available in DSpace on 2013-04-10T15:38:16Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_PerfilEpidemiologicoPrevalencia.pdf: 52716306 bytes, checksum: 27f1b77c2773453579b329d92b3bd9f3 (MD5) Previous issue date: 2003 / As doenças sexualmente transmissíveis (DST) estão entre os problemas de saúde pública mais comuns em todo o mundo, principalmente entre os adolescentes, pois eles são mais vulneráveis em relação à sexualidade, tanto em países industrializados como nos em desenvolvimento. Este estudo tem por objetivo investigar a prevalência de doenças sexualmente transmissíveis em escolares da rede pública municipal de ensino da área urbana do município de Porto Velho, Estado de Rondônia. Foram investigados 122 alunos da Escola Municipal de Ensino Fundamental Marechal Joaquim Vicente Rondon, na faixa etária de 11 a 19 anos, através de questionário de autopreenchimento e coleta de amostras de sangue, secreção uretral e vaginal. O método sorológico ELISA (Ensaio imunoenzimático) e a bacterioscopia pelo método de Gram foram os testes utilizados para detecção e identificação de DST. 84,4% dos estudantes responderam saber o que é uma DST, 82,8% informaram que usavam preservativo durante as relações sexuais para prevenir DST, 11,5% não utilizavam o preservativo e 5,7% afirmaram que selecionavam seus parceiros sexuais. Foram examinadas 83 amostras de soro pelo teste ELISA e 41 esfregaços corados pelo método de Gram. A prevalência encontrada para Chlamydia foi de 65,3% no sexo feminino e 34,6% no sexo masculino. Os agentes biopatogênicos encontrados com mais freqüência foram Gardnerella vaginalis, Candida albicans e Trichomonas vaginalis. / Sexually Transmitted Diseases (STD) are widespread public health concern, majority among adolescents, because they are most susceptible in respect of the sexuality. Early sexual initiation, multiple sex partners, and lack of condom use are considered risk factors and contribute to the increase in the number of STD cases. In order to better understand high-risk sexual behavior among students, a crosssectional study based on a self-answered anonymous questionnaire was conducted in Joaquim Vicente Rondon High School, a public school of Porto Velho city, Brazil. To verify STD's prevalence, samples of blood, urethral and vaginal discharge had been analyzed. A total of 122 students aged 11 to 19 years participated in the study. 84% known what is a STD, 82,8% informed always using condoms during sex, 11,5% didn't make use of condom, and 5,7% selected their sexual partner. To identify STD variety an enzyme-linked immunosorbent assay (ELISA test) and bacterioscopia by method of gram had been applied. 83 blood samples had been analyzed by ELISA test, and 41 smear tests had been stained by method of gramo The incidence to Chlamydia was observed in 65,3% of females, and 34,6% of young men. Gardnerella vaginalis, Candida albicans and Trichomonas vaginalis were more common pathogenic microorganisms found.

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-04-08T21:04:04Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AvaliacaoExposicaoCongenita.pdf: 312191 bytes, checksum: cb222a1d25b631394573251f5818d550 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-04-12T15:46:45Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AvaliacaoExposicaoCongenita.pdf: 312191 bytes, checksum: cb222a1d25b631394573251f5818d550 (MD5) / Made available in DSpace on 2013-04-12T15:46:45Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_AvaliacaoExposicaoCongenita.pdf: 312191 bytes, checksum: cb222a1d25b631394573251f5818d550 (MD5) Previous issue date: 2003 / Foram estudadas 100 mães com seus RN, em três maternidades da cidade de Porto Velho-RO, para a avaliação da exposição pré-natal ao mercúrio, através da verificação dos níveis de mercúrio total ao nascimento em amostras de cabelo da mãe e de recém-nascidos, sangue materno, cordão umbilical e placenta. As mães responderam a um questionário, com a finalidade de identificar fatores de risco para contaminação mercurial e todas as crianças foram submetidas ao exame físico de rotina. A análise laboratorial do mercúrio foi realizada no Laboratório de Biogeoquímica Ambiental da UNIR, pela técnica de espectrofotometria de absorção atômica; os resultados mostraram significante correlação entre as concentrações de mercúrio total na placenta e cordão umbilical, cabelo do RN, sangue materno e cabelo materno. Concluímos que ocorreu exposição congênita; que os níveis de concentração deste metal observados no estudo, não repercutiram diretamente sobre a idade gestacional; mas, apresentaram correlação significante entre a concentração mercurial e peso do RN, confirmados pelos valores encontrados no cabelo do RN. / A hundred mothers with their newborn babies, were studied, in three hospitals in the city of Porto Velho, for the evaluation of the prenatal exposure to mercury, through the study of the mercury level in the birth, the mother and newborn’s hair, mother’s blood, umbilical cord and placentas samples. The mothers answered a questionnaire, with the objective of identifying risk factors of mercury contamination and all children were subjected to the routine physical examination. The mercury analysis was carried in the Environmental Biogeochemical Laboratory of UNIR, through the spectrophotometry of atomic absorption technique, the results showed significant correlation among the total mercury concentration in the placenta and the umbilical cord, newborn hair, the mother’s blood and hair. We concluded that there was a congenit exposure, that the levels of concentration of this metal observed, in the study, didn’t affect directly on pregnantable age; but, showed significant connection between the mercury and concentration and the newborn weight , confirmed by the results found in the newborn’s hair.

<p>In sera remitted for anti-nuclear antibody (ANA) analysis, the supplement of a sensitive anti-SSA/Ro ELISA to the conventional ANA screening by immunofluorescence (IF) revealed that one fourth of the individuals with IF-ANA negative, but SSA/Ro ELISA positive sera, had systemic lupus erythematosus (SLE) or cutaneous LE. Consequently, adding a sensitive anti-SSA/Ro ELISA to the ANA screening is valuable for the serological detection of ANA negative SLE/LE patients.</p><p>SLE patients often have measurable interferon-alpha (IFN-α) levels in serum, and IFN-α treatment of patients with non-autoimmune diseases can induce SLE. Thus, the type I IFN system seems to be important in SLE and was therefore investigated. Initially, a decreased IFN-α producing capacity, due to a 70-fold reduction in the number of circulating natural IFN-α producing cells (NIPC), was noted in peripheral blood mononuclear cells (PBMC) from SLE patients. SLE-sera contained an endogenous IFN-α inducing factor (SLE-IIF), consisting of IgG and DNA in the form of small immune complexes (300-1000 kD). The SLE-IIF selectively activated NIPC and was more common in sera from patients with active disease compared to individuals with inactive disease. IFN-α producing cells could be detected by immunohistochemistry in both lesional and unaffected skin from SLE patients, and IFN-α gene transcription could be verified by in situ hybridisation in some of the skin biopsies. A reduced number of NIPC, detected by expression of the blood dendritic cell antigen (BDCA)-2, was noted among SLE-PBMC. The IFN-α production triggered by SLE-IIF in SLE-PBMC was inhibited by monoclonal antibodies (mAbs) to BDCA-2 and markedly decreased by anti-BDCA-4 mAbs. </p><p>The observations in the present thesis may explain the ongoing IFN-α production in SLE patients, indicate an important role for the activated type I IFN system in the pathogenesis, and suggest that direct targeting of SLE-NIPC may constitute a new therapeutic principle in SLE.</p>

In sera remitted for anti-nuclear antibody (ANA) analysis, the supplement of a sensitive anti-SSA/Ro ELISA to the conventional ANA screening by immunofluorescence (IF) revealed that one fourth of the individuals with IF-ANA negative, but SSA/Ro ELISA positive sera, had systemic lupus erythematosus (SLE) or cutaneous LE. Consequently, adding a sensitive anti-SSA/Ro ELISA to the ANA screening is valuable for the serological detection of ANA negative SLE/LE patients. SLE patients often have measurable interferon-alpha (IFN-α) levels in serum, and IFN-α treatment of patients with non-autoimmune diseases can induce SLE. Thus, the type I IFN system seems to be important in SLE and was therefore investigated. Initially, a decreased IFN-α producing capacity, due to a 70-fold reduction in the number of circulating natural IFN-α producing cells (NIPC), was noted in peripheral blood mononuclear cells (PBMC) from SLE patients. SLE-sera contained an endogenous IFN-α inducing factor (SLE-IIF), consisting of IgG and DNA in the form of small immune complexes (300-1000 kD). The SLE-IIF selectively activated NIPC and was more common in sera from patients with active disease compared to individuals with inactive disease. IFN-α producing cells could be detected by immunohistochemistry in both lesional and unaffected skin from SLE patients, and IFN-α gene transcription could be verified by in situ hybridisation in some of the skin biopsies. A reduced number of NIPC, detected by expression of the blood dendritic cell antigen (BDCA)-2, was noted among SLE-PBMC. The IFN-α production triggered by SLE-IIF in SLE-PBMC was inhibited by monoclonal antibodies (mAbs) to BDCA-2 and markedly decreased by anti-BDCA-4 mAbs. The observations in the present thesis may explain the ongoing IFN-α production in SLE patients, indicate an important role for the activated type I IFN system in the pathogenesis, and suggest that direct targeting of SLE-NIPC may constitute a new therapeutic principle in SLE.

No description available.

The recent discovery of the 31-km-wide Hiawatha impact crater has raised unanswered questions about its age, impactor and highly unusual organic carbon component. Previous research suggests a fractionated iron meteorite impactor, a probable maximum 3–2.4 Ma impact age and a possible Younger Dryas impact age. The first objective in this study has been to investigate a possible link between the Cape York meteorites and the Hiawatha impact crater by comparing the chromium isotopic signature in chromite from a Cape York meteorite with the chromium isotopic signature in potential chromite from the Hiawatha impactor. The second objective has been to investigate a possible Hiawatha signature in the Younger Dryas deposits from Baffin Bay. The third objective has been to study the organic carbon component in impactites derived from the Hiawatha impact crater. Heavy mineral grains were separated from glaciofluvial sediment which contains Hiawatha impactite grains. Not a single chromite grain was found and the possible link to the Cape York meteorites could not be tested. The petrographic examination of Younger Dryas marine deposits resulted in absence of impact-related Hiawatha grains. A petrological investigation revealed that organic carbon was likely found in five of six variably shocked impactites derived from the Hiawatha impact crater. The character of the organic carbon varies between the samples and also within individual samples. Vitrinite reflectance measurements of the organic carbon in two impactites yielded low reflectance values compared to charcoalification experiments of wood. Organic particles with different reflectance in the same sample suggest that the particles had different impact histories prior to settling and becoming a rock. Diagnostic conifer cellular texture was found in at least one of the samples. The character of the organic particles in the impactites supports the suggestion in a previous study that the sources of the Hiawatha organic carbon component are unmetamorphosed surficial deposits containing dead conifer tree trunks and fine-grained layered clay and organic matter.  In this study it is concluded that the apparent absence of chromite in the examined glaciofluvial sediment sample corroborates the significance of previous research which suggests that the Hiawatha impactor was an iron meteorite. The apparent absence of impact related grains in the Younger Dryas deposits suggests that although a Younger Dryas age for the Hiawatha impact crater is less likely now, the possibility remains open. The organic carbon with diagnostic conifer cellular texture in the Hiawatha impactites corroborates the conclusion in a previous study that the Hiawatha impact-related organic carbon component stems from local, thermally degraded conifer trees with a probable age of ca. 3–2.4 Ma. It is also concluded that the relatively low reflectance values of the organic carbon in the Hiawatha impactites seem to be related to the short duration of the high-temperature excursion during the hypervelocity impact event.

Abstract in English, Tsonga and Zulu / Mitlumbo ya mifambafambo ya le magondzweni i xin’wana xa miringeto (risks) yo biha ku tlula hinkwayo ya swifambo swa le gondzweni emisaveni hinkwayo, leswi yimelaka xiphiqo lexikulu xa swohanyaswin’we-ikhonomi ngopfu-ngopfu eka matiko lama ya ha hluvukaka tanihi Afrika-Dzonga. Ku va ku nyikiwa masungulo yo tiya ya xiikhonomi eka swiboho swa mbekiso ku tirhana na ntlhontlho lowu, i swa nkoka swinene ku hlela ndhurho wa mitlumbo leyi. Mipimanyeto leyi yi tirha tanihi nxopaxopo wa swinghenisiwa swa mbuyelo wa ndhurheriwo ku endlela ku kuma mphakelo wa switirhisiwa wo tirha kahle eka ku nghenelela eka ku tirhana na mitlhontlho leyi vangiwaka hi mitlumbano ya le magondzweni. Tiko ra Afrika-Dzonga a ri nga ri ku pfuxeteni ka mahungu ya mipimanyeto ya midurho ya mitlumbano ya le magondzweni nkarhi na nkarhi, naswona leyi a yi endliwa a yi tirhisa maendlelo lamo soriwa ngopfu yo languta nkoka wa vanhu (human capital). Hikwalaho, mipimanyeto leyi nga kona a yi nga ta va leyi tshembekaka eka ku kunguhata na ku pimaniseka na mipimanyeto ya matiko man’wana. Hi le ka ku landzelela vundzhaku lebyi laha dyondzo leyi yi nga tumbuluka na ku kombisa matirhiselo ya rimba ra ntirho wo katsa (hybrid) ku kambela ndhurho wa mitlumbo ya swifambo swa le magondzweni eAfrika-Dzonga. Rimba leri ri tirhisa endlelo ro kongomisa eka nkoka wa vanhu na ku pfumela ku hakela (willingness-to-pay), eka dyondzo yi ri yin’we. Mipimanyeto ya midurho ya nkoka wa vanhu ya laveka ku va yi pfuna eka ku kunguhata leswaku yi tlakusa swinenenene swihumesiwa swa rixaka, loko hala tlhelo mipimanyeto yo pfumela ku hakela yona yi ri yona yi fanelaka swinene eka ku pfuneta minghenelelo yo tlakusa nhlayiseko wa vanhu hi ku hunguta ku vaviseka na ku fa. Endlelo ro pfumela ku hakela ri tirhisa maendlelo ya swo ka swi nga ri swa makete (contingent valuation) na ya maendlelo yo langa (preference). Khwexinere yo valanga leyi a yi ri na maendlelo yo ka ya nga ri ya swa makete na swilangiwa leswi a swi boxiwile, yi tirhisiwile hi magoza mambirhi ku sampula vaanguri va 273 eka ntirho wa swo tleketla. Eka mhaka ya endlelo ro kongomisa eka nkoka wa vanhu, mipimanyeto ya ndhurho eka xiviko xa 2016 xa Cost of Crashes in South Africa yi hundzuluxiwile hi ku katsa inifulexini, ku tirhisiwa mpimo wa 2017 wa 5.3% ku kuma mipimanyeto ya ndhurho ya 2017. Dyondzo leyi yi paluxile leswaku endlelo ro kongomisa eka nkoka wa vanhu ri kayiveta ku vona ndhurho wa mitlumbo ya le magondzweni. Dyondzo leyi yi hoxa xandla eka ntsengo wa vutivi hi ku tirhisa endlelo ro languta nkoka wa vanhu na endlelo ro pfumela ku hakela eka dyondzo yi ri yin’we ku kombisa ntirhiseko wa endlelo leri ra nkatso (hybrid)/nhlanganiso eka xiyimo xa Afrika-Dzonga. Ndzavisiso wa nkarhi lowu taka wu fanele ku engeta dyondzo leyi hi sampulu leyi humaka eka swifundzakulu hinkwaswo swa nkaye swa Afrika-Dzonga, leswaku mipimanyeto ya ndhurho yi yimela vanhu va tiko hinkwaro. / Road traffic crashes are one of the worst risks of road mobility worldwide, representing a huge socio-economic problem particularly in developing countries such as South Africa. In order to provide a sound economic basis for investment decisions to address this challenge, it is critical to assess the cost of these crashes. These estimates serve cost-benefit analysis inputs to facilitate a more efficient resources allocation for interventions to address the challenge posed by road crashes. South Africa has not been updating crash cost estimates on a regular basis, and those that were conducted used the much criticised human capital approach. Therefore, the available estimates could not be relied upon for planning purposes and comparison with the estimates of other countries. It is against this background that this study developed and illustrated the application of a hybrid framework for assessing the cost of road traffic crashes in South Africa. The framework uses the human capital approach and the willingness-to-pay approach in one study. Human capital approach cost estimates are needed to inform planning to maximize the national output, while the willingness-to-pay estimates are more suitable when the main concern is to inform interventions to increase social welfare by reducing injuries and fatalities. The willingness-to-pay approach uses the contingent valuation and the stated preference methods. A survey questionnaire with contingent valuation and stated preference questions was administered in two phases to a sample of 273 respondents within the transport industry. For the human capital approach, the cost estimates in the 2016 Cost of Crashes in South Africa report were adjusted for inflation using the 2017 rate of 5.3% to obtain 2017 cost estimates. This study revealed that the human capital approach underestimates the cost of road crashes. The study contributes to the body of knowledge by using the human capital approach and the willingness-to-pay approach in one study to illustrate the applicability of this hybrid/ combination within the South African context. Future research needs to replicate this study on a sample drawn from all nine provinces of South Africa, so that the cost estimates are representative of the country’s population. / Ukuphazamiseka komgwaqo kungenye yezingozi ezimbi kakhulu zokuhamba komgwaqo emhlabeni jikelele, ezimele inkinga enkulu yenhlalo nezomnotho ikakhulukazi emazweni asathuthuka njengeNingizimu Afrika. Ukuze unikeze isisekelo sezomnotho esizwakalayo ezinqumeni zokutshala izimali ukubhekana nale nselele, kubalulekile ukuhlola izindleko zalezi zingozi. Lezi zilinganiso zisebenza njengeziphakamiso zokuhlaziywa kwezindleko zokuhlomula ukuze kube lula ukunikezwa kwezinsiza ezenzelwe ukuxazulula inselele ebangelwa ukuphazamiseka komgwaqo. INingizimu Afrika ayizange ibuyekeze ukulinganisa izindleko zezingozi njalo, futhi lezo ezenziwa zisebenzise indlela enkulu yokugxeka ukusebenzisa abantu. Ngakho-ke, izilinganiso ezitholakalayo azikwazanga ukuthenjelwa kuzona ngezinjongo zokuhlela nokuqhathaniswa nezilinganiso zamanye amazwe. Lokhu kuphikisana nalesi sigaba ukuthi lolu cwaningo lusungulwe futhi luboniswe ukusetshenziswa kohlaka oluxubile lokuhlola izindleko zokuphazamiseka komgwaqo eNingizimu Afrika. Uhlaka lusebenzisa indlela yokusebenzisa abantu kanye nendlela yokuzimisela-ukukhokha ocwaningweni olulodwa. Ukulinganiselwa kwezindleko zokusebenzisa abantu kuyadingeka ukuze kwaziswe ukuhlela ukwandisa umkhiqizo kazwelonke, kanti ukulinganiselwa kokuzimisela-ukukhokhela kukulungele kakhulu ukwazisa ukungenelela ukwandisa inhlalakahle yomphakathi ngokunciphisa ukulimala nokubulawa kwabantu. Indlela yokuzimisela-ukukhokha isebenzisa ukuhlaziywa kwesilinganiso kanye nezindlela okukhethwa ngazo. Imibuzo yokuhlola ngokuhlaziywa kwesilinganiso kanye nemibuzo ekhethwe ngayo yenziwa ngezigaba ezimbili embonakalisweni yabaphendulile abangama-273 embonini yezokuthutha. Ngokwendlela yokusebenzisa abantu, izindleko ezilinganiselwa ku-2016 Izindleko Zokushayisana eNingizimu Afrika kubikwa ukuthi zalungiselwa ukwenyuka kwamandla emali, kusetshenziswa isilinganiso sango-2017 esingu-5.3% ukuthola izindleko zango-2017. Lolu cwaningo luveze ukuthi indlela yokusebenzisa abantu ithatha kancane izindleko zokuphazamiseka komgwaqo. Ucwaningo lunomthelela emzimbeni wolwazi ngokusebenzisa indlela yokusebenzisa abantu kanye nendlela yokuzimisela-ukukhokha ocwaningweni olulodwa ukukhombisa ukufaneleka kwalesi sivumelwano / inhlanganisela ngaphakathi komongo waseNingizimu Afrika. Ucwaningo lwesikhathi esizayo ludinga ukuphindaphinda lolu cwaningo embonakalisweni othathwe kuzo zonke izifundazwe eziyisishiyagalolunye zaseNingizimu Afrika, ukuze ukulinganiswa kwezindleko kummele abantu bezwe / Business Management / D. Phil. (Management Studies)