[pt] Este trabalho investiga a produção das primeiras imagens acerca das terras e habitantes contatados pelos portugueses após a ultrapassagem do temível Cabo Bojador: a Guiné e os negros africanos. Analisa-se como foram organizadas e adaptadas as antigas concepções cosmológicas cristas frente a experiência do avanço das naus e dos limites do mundo conhecido. Para estudá-los, investiga-se dois conjuntos de fontes: as primeiras narrativas de viagens escritas por Gomes Eanes Zurara, Diogo Gomes, Luís Cadamosto e Duarte Pacheco Pereira; e uma coleção cartográfica composta por exemplares de mappaemundi, cartas-portulanos e mapas-múndi do início da era moderna. / [en] This work investigates the production of the first images about the lands and inhabitants contacted by the portugueses after overtaking the feared Cape Bojador: the Guinea and the black africans. We analyze how the old conceptions cosmological were organized and adapted after the advance of the experience of the Christian ships by unknown seas pushing the known world s limits. To study this subject, we investigate two sets of sources: the firsts travels writing made by Gomes Eanes Zurara, Diogo Gomes, Luiz Cadamosto e Duarte Pacheco Pereira; and a cartographic colection of mappaemundi, portulan charts and world maps in the early modern era.

Student Number : 9902006N - MSc(Med) Dissertation - School of Medicine - Faculty of Health Sciences / Hepatocellular carcinoma (HCC) is the most common primary malignant tumour of the liver. Aflatoxin B1 (AFB1) is a potent hepatocarcinogen, and dietary iron overload has been shown to contribute to HCC development in black africans. Both are well studied hepatotoxins. The aim of this study was to use a Wistar rat model over a 12 month period to investigate synergy and the extent thereof between AFB1 ingestion and dietary iron overload. 25ug/day of AFB1, reconstituted in DMSO, was administered by gavaging the animals, over a period of 10 days with a 2 day interval in between. The chow diet was supplemented with 0.75% (w/w) ferrocene iron. Experimental subjects were divided into 4 groups. Group 1 was fed the normal chow diet. Group 2 was fed 0.75% (w/w) ferrocene iron alone. Group 3 was gavaged 250μg AFB1 alone. Group 4 was fed the 0.75% (w/w) ferrocene iron and gavaged 250μg AFB1. A number of assays were conducted to investigate synergy. Colorimetric assays were used to measure serum iron, total-iron binding capacity, ALT, AST, GGT, nitrite production, lipid peroxidation and hydroxyproline concentrations. ELISA’s were used to determine ferritin, 8-isoprostane and 8-hydroxyguanosine concentrations. Nontransferrin bound iron was measured using an HPLC method. A chemiluminescent assay was used to measure superoxide anion production. Cytokines were measured using a suspension array system. Mutagenicity was assessed using the Ames mutagenicity assay using salmonella typhimirium strains TA97, TA98, TA100 and TA102. Iron profiling indicated that iron overloading occurred with the ingestion of the ferrocene diet. Biomarkers of oxidative stress, as illustrated by the measurement of 8-hydroxyguanosine and lipid peroxidation, showed additive synergistic effects between the two carcinogens. The anti-inflammatory interleukin-10 was shown to be markedly elevated with the co-administration of the two carcinogens, indicating the elevated inflammatory processes. Additive synergistic effects were noted in terms of the liver disease marker ALT. The salmonella typhimirium strain TA102 used in the Ames mutagenicity test showed increased colony counts with respect to the coadministration of carcinogens (P<0.05), although no synergistic effect was noted. In a few of the presented parameters, the AFB1 group was not significantly different to the control group, although significant differences between the Fe group and the Fe + AFB1 groups were noted. The implication of which is that the presence of AFB1 is increasing the activity of Fe as a carcinogen, thereby acting as a co-carcinogen. Examples of such parameters illustrating this are presented in the results section including serum ALT, serum nitrite, liver and serum lipid peroxidation, liver and serum 8-hydroxyguanosine, some of the mutagenicity assays, and interleukin-10. The conclusion of this study suggests that AFB1 acts as a co-carcinogen in the presence of iron overloading, implying that a synergistic relationship between these two toxins exists.

The impact of ethnic residential concentration on the process of integration of ethnic minorities into the mainstream society has been increasingly debated among both scholars and policy makers across Europe. This thesis seeks to contribute to this debate by addressing the effect of ethnic residential concentration on the political participation of Black Africans in Britain. The study pursues three main objectives: investigating the marginalising or mobilising impact of co-ethnic residential concentration on political participation; disentangling the processes underpinning this relationship by focusing on the effect of ethnic-based social networks, represented here by voluntary organisations, religious institutions and informal social networks; exploring the influence of the immigration-related heterogeneity that characterises the Black African community on the relationship between residential concentration, ethnic social networks and political participation. A mixed-method approach is adopted. The quantitative enquiry focuses on the Black African community as a whole and relies on secondary data drawn from the 2010 Ethnic Minority British Electoral Survey. The qualitative enquiry is based on primary data collected through face-to-face interviews and participant observation among Ghanaians and Somalis in London. The quantitative analysis shows that, among Black Africans, residential concentration has a mobilising effect on voter turnout but a marginalising effect on non-electoral participation. Ethnic social networks do not seem to mediate this relationship. Residential concentration is significantly, and positively, correlated to individual participation in ethnic places of worship and embeddedness in ethnic informal networks but not to involvement in ethnic organisations. In turn, the latter positively influences non-electoral engagement whereas ethnic places of worship and informal networks are not related to political engagement. The qualitative findings suggest that residential concentration is more relevant for the creation of and participation in ethnic organisations among Somalis than among Ghanaians. However, this relationship is likely to be influenced by other contextual factors such as institutional support, ethnic diversity and tribal homogeneity. Somali organisations also seem to play a more active political role than Ghanaian groups with regard to both electoral and non-electoral engagement. The two communities appear to be more similar when considering the relationship between ethnic religious institutions and informal connections with co-ethnics. These networks are not necessarily dependent on ethnic residential clustering and their effect on political engagement is primarily linked to informal political discussion. Overall, the results suggest that the relationship between residential concentration, ethnic social networks and political participation of Black Africans varies considerably between the two national groups researched, primarily due to their immigration-related characteristics, as well as across modes of political engagement (i.e. electoral, non-electoral) and local contexts.

No description available.

This thesis describes studies on the analysis of arsenic (As) in human biological samples, mainly urine but also hair and fingernails using inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GF-AAS). The relationship between ethnicity and arsenic metabolism was investigated for the first time for a population in the United Kingdom. This investigation has been carried out through comparative analysis of arsenic in human urine, hair and fingernails in volunteers from three different ethnic groups (Whites, Asians and Somali Black-Africans) who are only exposed to background levels of arsenic. Results obtained with 63 volunteers showed ethnic differences in urinary arsenic excretion as well as differences in arsenic levels in fingernail samples. The averages of total arsenic levels for the Somali Black-Africans (urine 7.2 µg/g creatinine; fingernails 723 µg/kg) are significantly (P< 0.05) different from both the Asians (urine 20.6 µg/g creatinine; fingernails 153.9 µg/kg) and Whites (urine 24.5 µg/g creatinine; fingernails 177.0 µg/kg). The Somali group also shows a higher percentage (50%) of dimethylarsinate (DMA) and a lower percentage (48%) of arsenobetaine (AB), compared to Asians (16% DMA and 83% AB) and Whites (22% DMA and 77% AB). The effect of fasting on urinary arsenic species distribution was also investigated by monitoring urine samples from 29 Ramadan fasting volunteers, with each volunteer providing a sample at the beginning (RF1) and at the end (RF2) of an approximately 12 hours fast. The results obtained showed the frequency of MA detection for RF2 was 12 and 2-fold higher than for the non-fasting and RF1 groups, respectively. This suggests fasting may alter the pattern of arsenic metabolism and excretion. However, there was no significant difference (P> 0.05) in the average of total level of arsenic for RF1 (18.3 µg/g creatinine) and RF2 (17.7 µg/g creatinine). A relationship between excretion of arsenic and selenium in individuals exposed to background levels of arsenic and selenium was investigated through analysis of urine samples from 93 volunteers from Leicester, UK. A positive correlation between arsenic and selenium was found and the As:Se ratio was 0.7 ± 0.4. The intra-individual variation of As:Se ratio does not alter significantly over time, as determined by monitoring urine samples from a volunteer over a period of one year. Furthermore, within a single day, with urine samples collected at the beginning and after a 12-hour fast, the As:Se ratio was found to be similar (0.7 ± 0.5). These findings suggest a close relationship between these two metalloids, the biological significance of which needs to be explored in the future.

Diese Arbeit, die auf persönlichen Erfahrungen als Asylbewerber in Deutschland basiert, fokussiert sich auf die sozioökonomische Integration von schwarzafrikanischen Asylbewerber:innen, d.h. mit einer Aufenthaltserlaubnis nach § 55 des deutschen Asylgesetzes, und von geduldeten Migrant:innen, d.h. mit einem Duldungsstatus nach § 60a des deutschen Aufenthaltsgesetzes. Die Arbeit untersucht ihre Teilnahme an deutschen Integrationskursen und ihren Zugang zu Arbeitserlaubnissen in den sechzehn Bundesländern, die von der Ausländerbehörde und der Bundesagentur für Arbeit streng kontrolliert werden. Die Ergebnisse zeigen, dass die Personen einer wirtschaftlichen Tätigkeit nachgehen, um ihren Lebensunterhalt in Deutschland zu bestreiten als auch um Familienangehörige in ihren Heimatländern zu unterstützen. Methodisch bedient sich die Arbeit eines Methodenmix, der ethno-soziogeographische Instrumente zur Datenerhebung, -verarbeitung und -analyse einsetzt. Zwischen 2016 und Juni 2021 wurden zwanzig Einzelfallstudien, dreihundert halbstrukturierte Fragebögen, sechs Fokusgruppendiskussionen mit der Zielgruppe und deutschen Beamten des Gerichts und der Ausländerbehörde sowie zwei Experteninterviews mit Abgeordneten deutscher Parlamente durchgeführt. Zu den aufgedeckten wirtschaftlichen Aktivitäten gehören der Drogenhandel, das Ausliefern von Zeitungen, informeller Streetfood-Verkauf, Friseurhandwerk, der Handel und das Testen auf Corona. Da informelle (illegale, halblegale und kriminelle) Wirtschaftspraktiken als Einstieg in den Arbeitsmarkt und als Reaktion auf die begrenzten Möglichkeiten der deutschen Behörden häufig genutzt werden, schließt die Arbeit mit der Aufforderung an die politischen Entscheidungsträger, den derzeitigen sozioökonomischen Integrationsrahmen für diese beiden Kategorien von Migrant:innen in Deutschland dringend zu überdenken. / This thesis, based on personal experience as an asylum seeker in Germany, focuses on the socio-economic integration of Black African asylum seekers, i.e. with a residence permission § 55 of the German Asylum Act, as well as tolerated migrants, i.e. with a toleration status § 60a German Residence Act. The thesis sheds light on their participation in German integration courses and their access to work permits across the sixteen German states, which are subject to strict regulations by the Foreigner Registration Office and the Federal Office of Work. The findings reveal that individuals engage in economic activities to financially sustain themselves within the territory and also to support family members in their home countries. Methodically, the thesis employs mixed methods, utilizing ethno-sociogeographical tools for data acquisition, processing, and analysis. Between 2016 and June 2021, the thesis conducted twenty individual case studies, three hundred semi-structured questionnaires, two expert interviews with members of German parliaments, six focus group discussions with the target group and German officials from the court, the Foreigner registration office. The economic activities uncovered include drug dealing, newspaper delivery, informal street food selling, hairdressing, trading, and COVID-19 testing. As there is a massive use of informal economic practices (illegal, semi-legal, and criminal) as entry point to the job market and as a response to limited opportunities provided by the German authorities, the thesis concludes with a call to policymakers to urgently reconsider the current socio-economic integration framework for this two categories of migrants in Germany.