Sensitivity and specificity of HAT Sero-K-SeT, a rapid diagnostic test for serodiagnosis of sleeping sickness caused by Trypanosoma brucei gambiense: a case-control study.

PubMed

Büscher, Philippe; Mertens, Pascal; Leclipteux, Thierry; Gilleman, Quentin; Jacquet, Diane; Mumba-Ngoyi, Dieudonné; Pyana, Patient Pati; Boelaert, Marleen; Lejon, Veerle

2014-06-01

Human African trypanosomiasis (HAT) is a life-threatening infection affecting rural populations in sub-Saharan Africa. Large-scale population screening by antibody detection with the Card Agglutination Test for Trypanosomiasis (CATT)/Trypanosoma brucei (T b) gambiense helped reduce the number of reported cases of gambiense HAT to fewer than 10 000 in 2011. Because low case numbers lead to decreased cost-effectiveness of such active screening, we aimed to assess diagnostic accuracy of a rapid serodiagnostic test (HAT Sero-K-SeT) applicable in primary health-care centres. In our case-control study, we assessed participants older than 11 years who presented for HAT Sero-K-SeT and CATT/T b gambiense at primary care centres or to mobile teams (and existing patients with confirmed disease status at these centres) in Bandundu Province, DR Congo. We defined cases as patients with trypanosomes that had been identified in lymph node aspirate, blood, or cerebrospinal fluid. During screening, we recruited controls without previous history of HAT or detectable trypanosomes in blood or lymph who resided in the same area as the cases. We assessed diagnostic accuracy of three antibody detection tests for gambiense HAT: HAT Sero-K-SeT and CATT/T b gambiense (done with venous blood at the primary care centres) and immune trypanolysis (done with plasma at the Institute of Tropical Medicine, Antwerp, Belgium). Between June 6, 2012, and Feb 25, 2013, we included 134 cases and 356 controls. HAT Sero-K-SeT had a sensitivity of 0·985 (132 true positives, 95% CI 0·947-0·996) and a specificity of 0·986 (351 true negatives, 0·968-0·994), which did not differ significantly from CATT/T b gambiense (sensitivity 95% CI 0·955, 95% CI 0·906-0·979 [128 true positives] and specificity 0·972, 0·949-0·985 [346 true negatives]) or immune trypanolysis (sensitivity 0·985, 0·947-0·996 [132 true positives] and specificity 0·980, 0·960-0·990 [349 true negatives]). The diagnostic accuracy

High prevalence of Trypanosoma brucei gambiense group 1 in pigs from the Fontem sleeping sickness focus in Cameroon.

PubMed

Simo, G; Asonganyi, T; Nkinin, S W; Njiokou, F; Herder, S

2006-06-30

To understand the importance of domestic pigs in the epidemiology of human trypanosomiasis, PCR was used to identify trypanosome populations in 133 pigs from the Fontem sleeping sickness focus of Cameroon. The results from this study show that 73.7% (98/133) of pigs from the Fontem area carry at least one trypanosome species. Trypanosoma vivax, T. brucei s.l. and T. congolense forest were found in 34.6% (46/133), 40.0% (53/133) and 46.0% (61/133) of the pigs respectively. T. simiae and T. congolense savannah were not identified in these animals. The use of repeated DNA sequences detected T. b. gambiense group 1 in 14.8% (15/101) of the pigs. Such pigs can be possible reservoir hosts for T. b. gambiense group 1 and contribute to the maintenance of the disease in the area. Mixed infections were revealed in 35.3% (47/133) of the pigs. Furthermore, we observed that under natural conditions, 52.4% (11/21) of the pigs from the Fontem focus carry mixed infections with T. b. gambiense group 1. No significant difference was observed between the percentage of T. b. gambiense group 1 single and mixed infections, and between the prevalence of this trypanosome in pigs from villages with and without sleeping sickness patients.

Trypanosoma brucei gambiense adaptation to different mammalian sera is associated with VSG expression site plasticity.

PubMed

Cordon-Obras, Carlos; Cano, Jorge; González-Pacanowska, Dolores; Benito, Agustin; Navarro, Miguel; Bart, Jean-Mathieu

2013-01-01

Trypanosoma brucei gambiense infection is widely considered an anthroponosis, although it has also been found in wild and domestic animals. Thus, fauna could act as reservoir, constraining the elimination of the parasite in hypo-endemic foci. To better understand the possible maintenance of T. b. gambiense in local fauna and investigate the molecular mechanisms underlying adaptation, we generated adapted cells lines (ACLs) by in vitro culture of the parasites in different mammalian sera. Using specific antibodies against the Variant Surface Glycoproteins (VSGs) we found that serum ACLs exhibited different VSG variants when maintained in pig, goat or human sera. Although newly detected VSGs were independent of the sera used, the consistent appearance of different VSGs suggested remodelling of the co-transcribed genes at the telomeric Expression Site (VSG-ES). Thus, Expression Site Associated Genes (ESAGs) sequences were analysed to investigate possible polymorphism selection. ESAGs 6 and 7 genotypes, encoding the transferrin receptor (TfR), expressed in different ACLs were characterised. In addition, we quantified the ESAG6/7 mRNA levels and analysed transferrin (Tf) uptake. Interestingly, the best growth occurred in pig and human serum ACLs, which consistently exhibited a predominant ESAG7 genotype and higher Tf uptake than those obtained in calf and goat sera. We also detected an apparent selection of specific ESAG3 genotypes in the pig and human serum ACLs, suggesting that other ESAGs could be involved in the host adaptation processes. Altogether, these results suggest a model whereby VSG-ES remodelling allows the parasite to express a specific set of ESAGs to provide selective advantages in different hosts. Finally, pig serum ACLs display phenotypic adaptation parameters closely related to human serum ACLs but distinct to parasites grown in calf and goat sera. These results suggest a better suitability of swine to maintain T. b. gambiense infection supporting

Blood-brain barrier traversal by African trypanosomes requires calcium signaling induced by parasite cysteine protease

PubMed Central

Nikolskaia, Olga V.; de A. Lima, Ana Paula C.; Kim, Yuri V.; Lonsdale-Eccles, John D.; Fukuma, Toshihide; Scharfstein, Julio; Grab, Dennis J.

2006-01-01

In this study we investigated why bloodstream forms of Trypanosoma brucei gambiense cross human brain microvascular endothelial cells (BMECs), a human blood-brain barrier (BBB) model system, at much greater efficiency than do T. b. brucei. After noting that T. b. gambiense displayed higher levels of cathepsin L–like cysteine proteases, we investigated whether these enzymes contribute to parasite crossing. First, we found that T. b. gambiense crossing of human BMECs was abrogated by N-methylpiperazine-urea-Phe-homopheylalanine-vinylsulfone-benzene (K11777), an irreversible inhibitor of cathepsin L–like cysteine proteases. Affinity labeling and immunochemical studies characterized brucipain as the K11777-sensitive cysteine protease expressed at higher levels by T. b. gambiense. K11777-treated T. b. gambiense failed to elicit calcium fluxes in BMECs, suggesting that generation of activation signals for the BBB is critically dependant on brucipain activity. Strikingly, crossing of T. b. brucei across the BBB was enhanced upon incubation with brucipain-rich supernatants derived from T. b. gambiense. The effects of the conditioned medium, which correlated with ability to evoke calcium fluxes, were canceled by K11777, but not by the cathepsin B inhibitor CA074. Collectively, these in vitro studies implicate brucipain as a critical driver of T. b. gambiense transendothelial migration of the human BBB. PMID:16998589

Sleeping Sickness in Travelers - Do They Really Sleep?

PubMed Central

Urech, Karin; Neumayr, Andreas; Blum, Johannes

2011-01-01

The number of imported Human African Trypanosomiasis (HAT) cases in non-endemic countries has increased over the last years. The objective of this analysis is to describe the clinical presentation of HAT in Caucasian travelers. Literature was screened (MEDLINE, Pubmed) using the terms “Human African Trypanosomiasis”, “travelers” and “expatriates”; all European languages except Slavic ones were included. Publications without clinical description of patients were only included in the epidemiological analysis. Forty-five reports on Caucasians with T.b. rhodesiense and 15 with T.b. gambiense infections were included in the analysis of the clinical parameters. Both species have presented with fever (T.b. rhodesiense 97.8% and T.b. gambiense 93.3%), headache (50% each) and a trypanosomal chancre (T.b. rhodesiense 84.4%, T.b. gambiense 46.7%). While sleeping disorders dominate the clinical presentation of HAT in endemic regions, there have been only rare reports in travelers: insomnia (T.b. rhodesiense 7.1%, T.b. gambiense 21.4%), diurnal somnolence (T.b. rhodesiense 4.8%, T.b. gambiense none). Surprisingly, jaundice has been seen in 24.2% of the Caucasian T.b. rhodesiense patients, but has never been described in HAT patients in endemic regions. These results contrast to the clinical presentation of T.b. gambiense and T.b. rhodesiense HAT in Africans in endemic regions, where the presentation of chronic T.b. gambiense and acute T.b. rhodesiense HAT is different. The analysis of 14 reports on T.b. gambiense HAT in Africans living in a non-endemic country shows that neurological symptoms such as somnolence (46.2%), motor deficit (64.3%) and reflex anomalies (14.3%) as well as psychiatric symptoms such as hallucinations (21.4%) or depression (21.4%) may dominate the clinical picture. Often, the diagnosis has been missed initially: some patients have even been hospitalized in psychiatric clinics. In travelers T.b. rhodesiense and gambiense present as acute

Sleeping sickness in travelers - do they really sleep?

PubMed

Urech, Karin; Neumayr, Andreas; Blum, Johannes

2011-11-01

The number of imported Human African Trypanosomiasis (HAT) cases in non-endemic countries has increased over the last years. The objective of this analysis is to describe the clinical presentation of HAT in Caucasian travelers. Literature was screened (MEDLINE, Pubmed) using the terms "Human African Trypanosomiasis", "travelers" and "expatriates"; all European languages except Slavic ones were included. Publications without clinical description of patients were only included in the epidemiological analysis. Forty-five reports on Caucasians with T.b. rhodesiense and 15 with T.b. gambiense infections were included in the analysis of the clinical parameters. Both species have presented with fever (T.b. rhodesiense 97.8% and T.b. gambiense 93.3%), headache (50% each) and a trypanosomal chancre (T.b. rhodesiense 84.4%, T.b. gambiense 46.7%). While sleeping disorders dominate the clinical presentation of HAT in endemic regions, there have been only rare reports in travelers: insomnia (T.b. rhodesiense 7.1%, T.b. gambiense 21.4%), diurnal somnolence (T.b. rhodesiense 4.8%, T.b. gambiense none). Surprisingly, jaundice has been seen in 24.2% of the Caucasian T.b. rhodesiense patients, but has never been described in HAT patients in endemic regions. These results contrast to the clinical presentation of T.b. gambiense and T.b. rhodesiense HAT in Africans in endemic regions, where the presentation of chronic T.b. gambiense and acute T.b. rhodesiense HAT is different. The analysis of 14 reports on T.b. gambiense HAT in Africans living in a non-endemic country shows that neurological symptoms such as somnolence (46.2%), motor deficit (64.3%) and reflex anomalies (14.3%) as well as psychiatric symptoms such as hallucinations (21.4%) or depression (21.4%) may dominate the clinical picture. Often, the diagnosis has been missed initially: some patients have even been hospitalized in psychiatric clinics. In travelers T.b. rhodesiense and gambiense present as acute illnesses and

Apolipoprotein L1 Variant Associated with Increased Susceptibility to Trypanosome Infection

PubMed Central

Cuypers, Bart; Lecordier, Laurence; Meehan, Conor J.; Van den Broeck, Frederik; Imamura, Hideo; Büscher, Philippe; Dujardin, Jean-Claude; Laukens, Kris; Schnaufer, Achim; Dewar, Caroline; Lewis, Michael; Balmer, Oliver; Azurago, Thomas; Kyei-Faried, Sardick; Ohene, Sally-Ann; Duah, Boateng; Homiah, Prince; Mensah, Ebenezer Kofi; Anleah, Francis; Franco, Jose Ramon; Pays, Etienne

2016-01-01

ABSTRACT African trypanosomes, except Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense, which cause human African trypanosomiasis, are lysed by the human serum protein apolipoprotein L1 (ApoL1). These two subspecies can resist human ApoL1 because they express the serum resistance proteins T. b. gambiense glycoprotein (TgsGP) and serum resistance-associated protein (SRA), respectively. Whereas in T. b. rhodesiense, SRA is necessary and sufficient to inhibit ApoL1, in T. b. gambiense, TgsGP cannot protect against high ApoL1 uptake, so different additional mechanisms contribute to limit this uptake. Here we report a complex interplay between trypanosomes and an ApoL1 variant, revealing important insights into innate human immunity against these parasites. Using whole-genome sequencing, we characterized an atypical T. b. gambiense infection in a patient in Ghana. We show that the infecting trypanosome has diverged from the classical T. b. gambiense strains and lacks the TgsGP defense mechanism against human serum. By sequencing the ApoL1 gene of the patient and subsequent in vitro mutagenesis experiments, we demonstrate that a homozygous missense substitution (N264K) in the membrane-addressing domain of this ApoL1 variant knocks down the trypanolytic activity, allowing the trypanosome to avoid ApoL1-mediated immunity. PMID:27073096

Trypanosome resistance to human innate immunity: targeting Achilles’ heel

PubMed Central

Stephens, Natalie A.; Kieft, Rudo; MacLeod, Annette; Hajduk, Stephen L.

2015-01-01

Trypanosome lytic factors (TLFs) are powerful, naturally-occurring toxins in humans that provide sterile protection against infection by several African trypanosomes. These trypanocidal complexes predominantly enter the parasite by binding to the trypanosome haptoglobin/hemoglobin receptor (HpHbR), trafficking to the lysosome, causing membrane damage and ultimately, cell lysis. Despite TLF-mediated immunity, the parasites that cause human African Trypanosomiasis (HAT), Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense, have developed independent mechanisms of resistance to TLF killing. Here we describe the parasite defenses that allow trypanosome infections of humans and discuss how targeting these apparent strengths of the parasite may reveal their Achilles’ heel, leading to new approaches in the treatment of HAT. PMID:23059119

Three Drug Combinations for Late-Stage Trypanosoma brucei gambiense Sleeping Sickness: A Randomized Clinical Trial in Uganda

PubMed Central

Priotto, Gerardo; Fogg, Carole; Balasegaram, Manica; Erphas, Olema; Louga, Albino; Checchi, Francesco; Ghabri, Salah; Piola, Patrice

2006-01-01

Objectives: Our objective was to compare the efficacy and safety of three drug combinations for the treatment of late-stage human African trypanosomiasis caused by Trypanosoma brucei gambiense. Design: This trial was a randomized, open-label, active control, parallel clinical trial comparing three arms. Setting: The study took place at the Sleeping Sickness Treatment Center run by Médecins Sans Frontières at Omugo, Arua District, Uganda Participants: Stage 2 patients diagnosed in Northern Uganda were screened for inclusion and a total of 54 selected. Interventions: Three drug combinations were given to randomly assigned patients: melarsoprol-nifurtimox (M+N), melarsoprol-eflornithine (M+E), and nifurtimox-eflornithine (N+E). Dosages were uniform: intravenous (IV) melarsoprol 1.8 mg/kg/d, daily for 10 d; IV eflornithine 400 mg/kg/d, every 6 h for 7 d; oral nifurtimox 15 (adults) or 20 (children <15 y) mg/kg/d, every 8 h for 10 d. Patients were followed up for 24 mo. Outcome Measures: Outcomes were cure rates and adverse events attributable to treatment. Results: Randomization was performed on 54 patients before enrollment was suspended due to unacceptable toxicity in one of the three arms. Cure rates obtained with the intention to treat analysis were M+N 44.4%, M+E 78.9%, and N+E 94.1%, and were significantly higher with N+E (p = 0.003) and M+E (p = 0.045) than with M+N. Adverse events were less frequent and less severe with N+E, resulting in fewer treatment interruptions and no fatalities. Four patients died who were taking melarsoprol-nifurtimox and one who was taking melarsoprol-eflornithine. Conclusions: The N+E combination appears to be a promising first-line therapy that may improve treatment of sleeping sickness, although the results from this interrupted study do not permit conclusive interpretations. Larger studies are needed to continue the evaluation of this drug combination in the treatment of T. b. gambiense sleeping sickness. PMID:17160135

Characterization of recombinant Trypanosoma brucei gambiense Translationally Controlled Tumor Protein (rTbgTCTP) and its interaction with Glossina midgut bacteria.

PubMed

Bossard, Géraldine; Bartoli, Manon; Fardeau, Marie-Laure; Holzmuller, Philippe; Ollivier, Bernard; Geiger, Anne

2017-09-03

In humans, sleeping sickness (i.e. Human African Trypanosomiasis) is caused by the protozoan parasites Trypanosoma brucei gambiense (Tbg) in West and Central Africa, and T. b. rhodesiense in East Africa. We previously showed in vitro that Tbg is able to excrete/secrete a large number of proteins, including Translationally Controlled Tumor Protein (TCTP). Moreover, the tctp gene was described previously to be expressed in Tbg-infected flies. Aside from its involvement in diverse cellular processes, we have investigated a possible alternative role within the interactions occurring between the trypanosome parasite, its tsetse fly vector, and the associated midgut bacteria. In this context, the Tbg tctp gene was synthesized and cloned into the baculovirus vector pAcGHLT-A, and the corresponding protein was produced using the baculovirus Spodoptera frugicola (strain 9) / insect cell system. The purified recombinant protein rTbgTCTP was incubated together with bacteria isolated from the gut of tsetse flies, and was shown to bind to 24 out of the 39 tested bacteria strains belonging to several genera. Furthermore, it was shown to affect the growth of the majority of these bacteria, especially when cultivated under microaerobiosis and anaerobiosis. Finally, we discuss the potential for TCTP to modulate the fly microbiome composition toward favoring trypanosome survival.

Candidate gene polymorphisms study between human African trypanosomiasis clinical phenotypes in Guinea.

PubMed

Kaboré, Justin Windingoudi; Ilboudo, Hamidou; Noyes, Harry; Camara, Oumou; Kaboré, Jacques; Camara, Mamadou; Koffi, Mathurin; Lejon, Veerle; Jamonneau, Vincent; MacLeod, Annette; Hertz-Fowler, Christiane; Belem, Adrien Marie Gaston; Matovu, Enock; Bucheton, Bruno; Sidibe, Issa

2017-08-01

Human African trypanosomiasis (HAT), a lethal disease induced by Trypanosoma brucei gambiense, has a range of clinical outcomes in its human host in West Africa: an acute form progressing rapidly to second stage, spontaneous self-cure and individuals able to regulate parasitaemia at very low levels, have all been reported from endemic foci. In order to test if this clinical diversity is influenced by host genetic determinants, the association between candidate gene polymorphisms and HAT outcome was investigated in populations from HAT active foci in Guinea. Samples were collected from 425 individuals; comprising of 232 HAT cases, 79 subjects with long lasting positive and specific serology but negative parasitology and 114 endemic controls. Genotypes of 28 SNPs in eight genes passed quality control and were used for an association analysis. IL6 rs1818879 allele A (p = 0.0001, OR = 0.39, CI95 = [0.24-0.63], BONF = 0.0034) was associated with a lower risk of progressing from latent infection to active disease. MIF rs36086171 allele G seemed to be associated with an increased risk (p = 0.0239, OR = 1.65, CI95 = [1.07-2.53], BONF = 0.6697) but did not remain significant after Bonferroni correction. Similarly MIF rs12483859 C allele seems be associated with latent infections (p = 0.0077, OR = 1.86, CI95 = [1.18-2.95], BONF = 0.2157). We confirmed earlier observations that APOL1 G2 allele (DEL) (p = 0.0011, OR = 2.70, CI95 = [1.49-4.91], BONF = 0.0301) is associated with a higher risk and APOL1 G1 polymorphism (p = 0.0005, OR = 0.45, CI95 = [0.29-0.70], BONF = 0.0129) with a lower risk of developing HAT. No associations were found with other candidate genes. Our data show that host genes are involved in modulating Trypanosoma brucei gambiense infection outcome in infected individuals from Guinea with IL6 rs1818879 being associated with a lower risk of progressing to active HAT. These results enhance our understanding of host-parasite interactions and, ultimately, may

Recombinant antigens expressed in Pichia pastoris for the diagnosis of sleeping sickness caused by Trypanosoma brucei gambiense.

PubMed

Rogé, Stijn; Van Nieuwenhove, Liesbeth; Meul, Magali; Heykers, Annick; Brouwer de Koning, Annette; Bebronne, Nicolas; Guisez, Yves; Büscher, Philippe

2014-07-01

Screening tests for gambiense sleeping sickness, such as the CATT/T. b. gambiense and a recently developed lateral flow tests, are hitherto based on native variant surface glycoproteins (VSGs), namely LiTat 1.3 and LiTat 1.5, purified from highly virulent trypanosome strains grown in rodents. We have expressed SUMO (small ubiquitin-like modifier) fusion proteins of the immunogenic N-terminal part of these antigens in the yeast Pichia pastoris. The secreted recombinant proteins were affinity purified with yields up to 10 mg per liter cell culture. The diagnostic potential of each separate antigen and a mixture of both antigens was confirmed in ELISA on sera from 88 HAT patients and 74 endemic non-HAT controls. Replacement of native antigens in the screening tests for sleeping sickness by recombinant proteins will eliminate both the infection risk for the laboratory staff during antigen production and the need for laboratory animals. Upscaling production of recombinant antigens, e.g. in biofermentors, is straightforward thus leading to improved standardisation of antigen production and reduced production costs, which on their turn will increase the availability and affordability of the diagnostic tests needed for the elimination of gambiense HAT.

A new transmission risk index for human African trypanosomiasis and its application in the identification of sites of high transmission of sleeping sickness in the Fontem focus of southwest Cameroon.

PubMed

Njitchouang, G R; Njiokou, F; Nana-Djeunga, H; Asonganyi, T; Fewou-Moundipa, P; Cuny, G; Simo, G

2011-09-01

A new index for the risk for transmission of human African trypanosomiasis was developed from an earlier index by adding terms for the proportion of tsetse infected with Trypanosoma brucei gambiense group 1 and the contribution of animals to tsetse diet. The validity of the new index was then assessed in the Fontem focus of southwest Cameroon. Averages of 0.66 and 4.85 Glossina palpalis palpalis (Diptera: Glossinidae) were caught per trap/day at the end of one rainy season (November) and the start of the next (April), respectively. Of 1596 tsetse flies examined, 4.7% were positive for Trypanosoma brucei s.l. midgut infections and 0.6% for T. b. gambiense group 1. Among 184 bloodmeals identified, 55.1% were from pigs, 25.2% from humans, 17.6% from wild animals and 1.2% from goats. Of the meals taken from humans, 81.5% were taken at sites distant from pigsties. At the end of the rainy season, catches were low and similar between biotopes distant from and close to pigsties, but the risk for transmission was greatest at sites distant from the sties, suggesting that the presence of pigs reduced the risk to humans. At the beginning of the rainy season, catches of tsetse and risk for transmission were greatest close to the sties. In all seasons, there was a strong correlation between the old and new indices, suggesting that both can be used to estimate the level of transmission, but as the new index is the more comprehensive, it may be more accurate. © 2010 The Authors. Medical and Veterinary Entomology © 2010 The Royal Entomological Society.

Discovery and Verification of Osteopontin and Beta-2-microglobulin as Promising Markers for Staging Human African Trypanosomiasis*

PubMed Central

Tiberti, Natalia; Hainard, Alexandre; Lejon, Veerle; Robin, Xavier; Ngoyi, Dieudonné Mumba; Turck, Natacha; Matovu, Enock; Enyaru, John; Ndung'u, Joseph Mathu; Scherl, Alexander; Dayon, Loïc; Sanchez, Jean-Charles

2010-01-01

Human African trypanosomiasis, or sleeping sickness, is a parasitic disease endemic in sub-Saharan Africa, transmitted to humans through the bite of a tsetse fly. The first or hemolymphatic stage of the disease is associated with presence of parasites in the bloodstream, lymphatic system, and body tissues. If patients are left untreated, parasites cross the blood-brain barrier and invade the cerebrospinal fluid and the brain parenchyma, giving rise to the second or meningoencephalitic stage. Stage determination is a crucial step in guiding the choice of treatment, as drugs used for S2 are potentially dangerous. Current staging methods, based on counting white blood cells and demonstrating trypanosomes in cerebrospinal fluid, lack specificity and/or sensitivity. In the present study, we used several proteomic strategies to discover new markers with potential for staging human African trypanosomiasis. Cerebrospinal fluid (CSF) samples were collected from patients infected with Trypanosoma brucei gambiense in the Democratic Republic of Congo. The stage was determined following the guidelines of the national control program. The proteome of the samples was analyzed by two-dimensional gel electrophoresis (n = 9), and by sixplex tandem mass tag (TMT) isobaric labeling (n = 6) quantitative mass spectrometry. Overall, 73 proteins were overexpressed in patients presenting the second stage of the disease. Two of these, osteopontin and β-2-microglobulin, were confirmed to be potential markers for staging human African trypanosomiasis (HAT) by Western blot and ELISA. The two proteins significantly discriminated between S1 and S2 patients with high sensitivity (68% and 78%, respectively) for 100% specificity, and a combination of both improved the sensitivity to 91%. The levels of osteopontin and β-2-microglobulin in CSF of S2 patients (μg/ml range), as well as the fold increased concentration in S2 compared with S1 (3.8 and 5.5 respectively) make the two markers good

Melarsoprol sensitivity profile of Trypanosoma brucei gambiense isolates from cured and relapsed sleeping sickness patients from the Democratic Republic of the Congo.

PubMed

Pyana Pati, Patient; Van Reet, Nick; Mumba Ngoyi, Dieudonné; Ngay Lukusa, Ipos; Karhemere Bin Shamamba, Stomy; Büscher, Philippe

2014-10-01

Sleeping sickness caused by Trypanosoma brucei (T.b.) gambiense constitutes a serious health problem in sub-Sahara Africa. In some foci, alarmingly high relapse rates were observed in patients treated with melarsoprol, which used to be the first line treatment for patients in the neurological disease stage. Particularly problematic was the situation in Mbuji-Mayi, East Kasai Province in the Democratic Republic of the Congo with a 57% relapse rate compared to a 5% relapse rate in Masi-Manimba, Bandundu Province. The present study aimed at investigating the mechanisms underlying the high relapse rate in Mbuji-Mayi using an extended collection of recently isolated T.b. gambiense strains from Mbuji-Mayi and from Masi-Manimba. Forty five T.b. gambiense strains were used. Forty one were isolated from patients that were cured or relapsed after melarsoprol treatment in Mbuji-Mayi. In vivo drug sensitivity tests provide evidence of reduced melarsoprol sensitivity in these strains. This reduced melarsoprol sensitivity was not attributable to mutations in TbAT1. However, in all these strains, irrespective of the patient treatment outcome, the two aquaglyceroporin (AQP) 2 and 3 genes are replaced by chimeric AQP2/3 genes that may be associated with resistance to pentamidine and melarsoprol. The 4 T.b. gambiense strains isolated in Masi-Manimba contain both wild-type AQP2 and a different chimeric AQP2/3. These findings suggest that the reduced in vivo melarsoprol sensitivity of the Mbuji-Mayi strains and the high relapse rates in that sleeping sickness focus are caused by mutations in the AQP2/AQP3 locus and not by mutations in TbAT1. We conclude that mutations in the TbAQP2/3 locus of the local T.b. gambiense strains may explain the high melarsoprol relapse rates in the Mbuji-Mayi focus but other factors must also be involved in the treatment outcome of individual patients.

Clinical and pathological aspects of human African trypanosomiasis (T. b. gambiense) with particular reference to reactive arsenical encephalopathy.

PubMed

Haller, L; Adams, H; Merouze, F; Dago, A

1986-01-01

Fourteen of 330 patients treated with melarsoprol (Mel B) for human African trypanosomiasis (HAT) developed a severe reactive arsenical encephalopathy (RAE). Six of these cases were fatal and postmortem examination was performed on 5 patients. Symptoms of "sleeping sickness" were compared with symptoms after treatment with arsenicals and the subsequent onset of RAE. There are 3 characteristic syndromes of RAE: convulsive status associated with acute cerebral edema, rapidly progressive coma without convulsions, and acute nonlethal mental disturbances without neurological signs. Three subjects revealed hypoxic brain damage with acute cerebral edema, and multiple hemorrhages of brain stem in those comatose. The pathology of the underlying HAT (chronic perivascular inflammation and plasma cytic infiltration of the brain) and the pathology of the RAE (characterized by acute vasculitis) are distinct. RAE occurs in the first as well as in the second stage (CNS involvement) of trypanosomiasis but the reason for this is unclear; an exclusive toxicity of the drug, or a Herxheimer reaction are possible but seem unlikely. Both clinical and laboratory findings point rather to a drug-related, delayed immune response.

Loop-Mediated Isothermal Amplification Test for Trypanosoma gambiense Group 1 with Stem Primers: A Molecular Xenomonitoring Test for Sleeping Sickness.

PubMed

Njiru, Zablon K; Mbae, Cecilia K; Mburugu, Gitonga N

2017-01-01

The World Health Organization has targeted Human African Trypanosomiasis (HAT) for elimination by 2020 with zero incidence by 2030. To achieve and sustain this goal, accurate and easy-to-deploy diagnostic tests for Gambian trypanosomiasis which accounts for over 98% of reported cases will play a crucial role. Most needed will be tools for surveillance of pathogen in vectors (xenomonitoring) since population screening tests are readily available. The development of new tests is expensive and takes a long time while incremental improvement of existing technologies that have potential for xenomonitoring may offer a shorter pathway to tools for HAT surveillance. We have investigated the effect of including a second set of reaction accelerating primers (stem primers) to the standard T. brucei gambiense LAMP test format. The new test format was analyzed with and without outer primers. Amplification was carried out using Rotorgene 6000 and the portable ESE Quant amplification unit capable of real-time data output. The stem LAMP formats indicated shorter time to results (~8 min), were 10-100-fold more sensitive, and indicated higher diagnostic sensitivity and accuracy compared to the standard LAMP test. It was possible to confirm the predicted product using ESE melt curves demonstrating the potential of combining LAMP and real-time technologies as possible tool for HAT molecular xenomonitoring.

Monitoring the elimination of human African trypanosomiasis: Update to 2014

PubMed Central

Priotto, Gerardo; Paone, Massimo; Diarra, Abdoulaye; Grout, Lise; Mattioli, Raffaele C.; Argaw, Daniel

2017-01-01

Background The World Health Organization (WHO) has targeted the elimination of Human African trypanosomiasis (HAT) ‘as a public health problem’ by 2020. The selected indicators of elimination should be monitored every two years, and we provide here a comprehensive update to 2014. The monitoring system is underpinned by the Atlas of HAT. Results With 3,797 reported cases in 2014, the corresponding milestone (5,000 cases) was surpassed, and the 2020 global target of ‘fewer than 2,000 reported cases per year’ seems within reach. The areas where HAT is still a public health problem (i.e. > 1 HAT reported case per 10,000 people per year) have halved in less than a decade, and in 2014 they corresponded to 350 thousand km2. The number and potential coverage of fixed health facilities offering diagnosis and treatment for HAT has expanded, and approximately 1,000 are now operating in 23 endemic countries. The observed trends are supported by sustained surveillance and improved reporting. Discussion HAT elimination appears to be on track. For gambiense HAT, still accounting for the vast majority of reported cases, progress continues unabated in a context of sustained intensity of screening activities. For rhodesiense HAT, a slow-down was observed in the last few years. Looking beyond the 2020 target, innovative tools and approaches will be increasingly needed. Coordination, through the WHO network for HAT elimination, will remain crucial to overcome the foreseeable and unforeseeable challenges that an elimination process will inevitably pose. PMID:28531222

Population genetics of Trypanosoma brucei gambiense in sleeping sickness patients with treatment failures in the focus of Mbuji-Mayi, Democratic Republic of the Congo.

PubMed

Pyana, Patient Pati; Sere, Modou; Kaboré, Jacques; De Meeûs, Thierry; MacLeod, Annette; Bucheton, Bruno; Van Reet, Nick; Büscher, Philippe; Belem, Adrien Marie Gaston; Jamonneau, Vincent

2015-03-01

Human African trypanosomiasis (HAT) in the Democratic Republic of the Congo (DRC) is caused by the protozoan Trypanosoma brucei gambiense. Until recently, all patients in the second or neurological stage of the disease were treated with melarsoprol. At the end of the past and the beginning of the present century, alarmingly high relapse rates in patients treated with melarsoprol were reported in isolated HAT foci. In the Mbuji-Mayi focus of DRC, a particular mutation that confers cross resistance for pentamidine and melarsoprol was recently found for all strains studied. Nevertheless, treatment successfully cured a significant proportion of patients. To check for the existence of other possible genetic factors of the parasites, we genotyped trypanosomes isolated from patients before and after treatment (relapsing patients) with eight microsatellite markers. We found no evidence of any genetic correlation between parasite genotype and treatment outcome and we concluded that relapse or cure probably depend more on patients' factors such as disease progression, nutritional or immunological status or co-infections with other pathogens. The existence of a melarsoprol and pentamidine resistance associated mutation at such high rates highlights an increasing problem, even for other drugs, especially those using the same transporters as melarsoprol and pentamidine. Copyright © 2014 Elsevier B.V. All rights reserved.

Epidemiology of Sleeping Sickness in Boffa (Guinea): Where Are the Trypanosomes?

PubMed Central

Kagbadouno, Moise Saa; Camara, Mamadou; Rouamba, Jeremi; Rayaisse, Jean-Baptiste; Traoré, Ibrahima Sory; Camara, Oumou; Onikoyamou, Mory Fassou; Courtin, Fabrice; Ravel, Sophie; de Meeûs, Thierry; Bucheton, Bruno; Jamonneau, Vincent; Solano, Philippe

2012-01-01

Human African Trypanosomiasis (HAT) in West Africa is a lethal, neglected disease caused by Trypanosoma brucei gambiense transmitted by the tsetse Glossina palpalis gambiensis. Although the littoral part of Guinea with its typical mangrove habitat is the most prevalent area in West Africa, very few data are available on the epidemiology of the disease in such biotopes. As part of a HAT elimination project in Guinea, we carried a cross-sectional study of the distribution and abundance of people, livestock, tsetse and trypanosomes in the focus of Boffa. An exhaustive census of the human population was done, together with spatial mapping of the area. Entomological data were collected, a human medical survey was organized together with a survey in domestic animals. In total, 45 HAT cases were detected out of 14445 people who attended the survey, these latter representing 50.9% of the total population. Potential additional carriers of T. b. gambiense were also identified by the trypanolysis test (14 human subjects and two domestic animals). No trypanosome pathogenic to animals were found, neither in the 874 tsetse dissected nor in the 300 domestic animals sampled. High densities of tsetse were found in places frequented by humans, such as pirogue jetties, narrow mangrove channels and watering points. The prevalence of T. b. gambiense in humans, combined to low attendance of the population at risk to medical surveys, and to an additional proportion of human and animal carriers of T. b. gambiense who are not treated, highlights the limits of strategies targeting HAT patients only. In order to stop T. b. gambiense transmission, vector control should be added to the current strategy of case detection and treatment. Such an integrated strategy will combine medical surveillance to find and treat cases, and vector control activities to protect people from the infective bites of tsetse. PMID:23272259

The skin is a significant but overlooked anatomical reservoir for vector-borne African trypanosomes

PubMed Central

Capewell, Paul; Cren-Travaillé, Christelle; Marchesi, Francesco; Johnston, Pamela; Clucas, Caroline; Benson, Robert A; Gorman, Taylor-Anne; Calvo-Alvarez, Estefania; Crouzols, Aline; Jouvion, Grégory; Jamonneau, Vincent; Weir, William; Stevenson, M Lynn; O'Neill, Kerry; Cooper, Anneli; Swar, Nono-raymond Kuispond; Bucheton, Bruno; Ngoyi, Dieudonné Mumba; Garside, Paul

2016-01-01

The role of mammalian skin in harbouring and transmitting arthropod-borne protozoan parasites has been overlooked for decades as these pathogens have been regarded primarily as blood-dwelling organisms. Intriguingly, infections with low or undetected blood parasites are common, particularly in the case of Human African Trypanosomiasis caused by Trypanosoma brucei gambiense. We hypothesise, therefore, the skin represents an anatomic reservoir of infection. Here we definitively show that substantial quantities of trypanosomes exist within the skin following experimental infection, which can be transmitted to the tsetse vector, even in the absence of detectable parasitaemia. Importantly, we demonstrate the presence of extravascular parasites in human skin biopsies from undiagnosed individuals. The identification of this novel reservoir requires a re-evaluation of current diagnostic methods and control policies. More broadly, our results indicate that transmission is a key evolutionary force driving parasite extravasation that could further result in tissue invasion-dependent pathology. DOI: http://dx.doi.org/10.7554/eLife.17716.001 PMID:27653219

An African Perspective on Human Rights.

ERIC Educational Resources Information Center

Shiman, David

1992-01-01

Presents a series of classroom activities comparing differing views of human rights in the United Nations Universal Declaration of Human Rights and the African Charter on Human and People's Rights. Includes excerpts from the African Charter on Human and People's Rights and the full text of the Universal Declaration of Human Rights. (CFR)

Assessing Strategies Against Gambiense Sleeping Sickness Through Mathematical Modeling

PubMed Central

Rock, Kat S; Ndeffo-Mbah, Martial L; Castaño, Soledad; Palmer, Cody; Pandey, Abhishek; Atkins, Katherine E; Ndung’u, Joseph M; Hollingsworth, T Déirdre; Galvani, Alison; Bever, Caitlin; Chitnis, Nakul; Keeling, Matt J

2018-01-01

Abstract Background Control of gambiense sleeping sickness relies predominantly on passive and active screening of people, followed by treatment. Methods Mathematical modeling explores the potential of 3 complementary interventions in high- and low-transmission settings. Results Intervention strategies that included vector control are predicted to halt transmission most quickly. Targeted active screening, with better and more focused coverage, and enhanced passive surveillance, with improved access to diagnosis and treatment, are both estimated to avert many new infections but, when used alone, are unlikely to halt transmission before 2030 in high-risk settings. Conclusions There was general model consensus in the ranking of the 3 complementary interventions studied, although with discrepancies between the quantitative predictions due to differing epidemiological assumptions within the models. While these predictions provide generic insights into improving control, the most effective strategy in any situation depends on the specific epidemiology in the region and the associated costs. PMID:29860287

Sensitivity and Specificity of a Prototype Rapid Diagnostic Test for the Detection of Trypanosoma brucei gambiense Infection: A Multi-centric Prospective Study.

PubMed

Bisser, Sylvie; Lumbala, Crispin; Nguertoum, Etienne; Kande, Victor; Flevaud, Laurence; Vatunga, Gedeao; Boelaert, Marleen; Büscher, Philippe; Josenando, Theophile; Bessell, Paul R; Biéler, Sylvain; Ndung'u, Joseph M

2016-04-01

A major challenge in the control of human African trypanosomiasis (HAT) is lack of reliable diagnostic tests that are rapid and easy to use in remote areas where the disease occurs. In Trypanosoma brucei gambiense HAT, the Card Agglutination Test for Trypanosomiasis (CATT) has been the reference screening test since 1978, usually on whole blood, but also in a 1/8 dilution (CATT 1/8) to enhance specificity. However, the CATT is not available in a single format, requires a cold chain for storage, and uses equipment that requires electricity. A solution to these challenges has been provided by rapid diagnostic tests (RDT), which have recently become available. A prototype immunochromatographic test, the SD BIOLINE HAT, based on two native trypanosomal antigens (VSG LiTat 1.3 and VSG LiTat 1.5) has been developed. We carried out a non-inferiority study comparing this prototype to the CATT 1/8 in field settings. The prototype SD BIOLINE HAT, the CATT Whole Blood and CATT 1/8 were systematically applied on fresh blood samples obtained from 14,818 subjects, who were prospectively enrolled through active and passive screening in clinical studies in three endemic countries of central Africa: Angola, the Democratic Republic of the Congo and the Central African Republic. One hundred and forty nine HAT cases were confirmed by parasitology. The sensitivity and specificity of the prototype SD BIOLINE HAT was 89.26% (95% confidence interval (CI) = 83.27-93.28) and 94.58% (95% CI = 94.20-94.94) respectively. The sensitivity and specificity of the CATT on whole blood were 93.96% (95% CI = 88.92-96.79) and 95.91% (95% CI = 95.58-96.22), and of the CATT 1/8 were 89.26% (95% CI = 83.27-93.28) and 98.88% (95% CI = 98.70-99.04) respectively. After further optimization, the prototype SD BIOLINE HAT could become an alternative to current screening methods in primary healthcare settings in remote, resource-limited regions where HAT typically occurs.

State of the Art in African Trypanosome Drug Discovery

PubMed Central

Jacobs, Robert T.; Nare, Bakela; Phillips, Margaret A.

2011-01-01

African sleeping sickness is endemic in sub-Saharan Africa where the WHO estimates that 60 million people are at risk for the disease. Human African trypanosomiasis (HAT) is 100% fatal if untreated and the current drug therapies have significant limitations due to toxicity and difficult treatment regimes. No new chemical agents have been approved since eflornithine in 1990. The pentamidine analog DB289, which was in late stage clinical trials for the treatment of early stage HAT recently failed due to toxicity issues. A new protocol for the treatment of late-stage T. brucei gambiense that uses combination nifurtomox/eflornithine (NECT) was recently shown to have better safety and efficacy than eflornithine alone, while being easier to administer. This breakthrough represents the only new therapy for HAT since the approval of eflornithine. A number of research programs are on going to exploit the unusual biochemical pathways in the parasite to identify new targets for target based drug discovery programs. HTS efforts are also underway to discover new chemical entities through whole organism screening approaches. A number of inhibitors with anti-trypanosomal activity have been identified by both approaches, but none of the programs are yet at the stage of identifying a preclinical candidate. This dire situation underscores the need for continued effort to identify new chemical agents for the treatment of HAT. PMID:21401507

Pleistocene North African genomes link Near Eastern and sub-Saharan African human populations.

PubMed

van de Loosdrecht, Marieke; Bouzouggar, Abdeljalil; Humphrey, Louise; Posth, Cosimo; Barton, Nick; Aximu-Petri, Ayinuer; Nickel, Birgit; Nagel, Sarah; Talbi, El Hassan; El Hajraoui, Mohammed Abdeljalil; Amzazi, Saaïd; Hublin, Jean-Jacques; Pääbo, Svante; Schiffels, Stephan; Meyer, Matthias; Haak, Wolfgang; Jeong, Choongwon; Krause, Johannes

2018-05-04

North Africa is a key region for understanding human history, but the genetic history of its people is largely unknown. We present genomic data from seven 15,000-year-old modern humans, attributed to the Iberomaurusian culture, from Morocco. We find a genetic affinity with early Holocene Near Easterners, best represented by Levantine Natufians, suggesting a pre-agricultural connection between Africa and the Near East. We do not find evidence for gene flow from Paleolithic Europeans to Late Pleistocene North Africans. The Taforalt individuals derive one-third of their ancestry from sub-Saharan Africans, best approximated by a mixture of genetic components preserved in present-day West and East Africans. Thus, we provide direct evidence for genetic interactions between modern humans across Africa and Eurasia in the Pleistocene. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

A literature review of economic evaluations for a neglected tropical disease: human African trypanosomiasis ("sleeping sickness").

PubMed

Sutherland, C Simone; Yukich, Joshua; Goeree, Ron; Tediosi, Fabrizio

2015-02-01

Human African trypanosomiasis (HAT) is a disease caused by infection with the parasite Trypanosoma brucei gambiense or T. b. rhodesiense. It is transmitted to humans via the tsetse fly. Approximately 70 million people worldwide were at risk of infection in 1995, and approximately 20,000 people across Africa are infected with HAT. The objective of this review was to identify existing economic evaluations in order to summarise cost-effective interventions to reduce, control, or eliminate the burden of HAT. The studies included in the review were compared and critically appraised in order to determine if there were existing standardised methods that could be used for economic evaluation of HAT interventions or if innovative methodological approaches are warranted. A search strategy was developed using keywords and was implemented in January 2014 in several databases. The search returned a total of 2,283 articles. After two levels of screening, a total of seven economic evaluations were included and underwent critical appraisal using the Scottish Intercollegiate Guidelines Network (SIGN) Methodology Checklist 6: Economic Evaluations. Results from the existing studies focused on the cost-effectiveness of interventions for the control and reduction of disease transmission. Modelling was a common method to forecast long-term results, and publications focused on interventions by category, such as case detection, diagnostics, drug treatments, and vector control. Most interventions were considered cost-effective based on the thresholds described; however, the current treatment, nifurtomix-eflornithine combination therapy (NECT), has not been evaluated for cost-effectiveness, and considerations for cost-effective strategies for elimination have yet to be completed. Overall, the current evidence highlights the main components that play a role in control; however, economic evaluations of HAT elimination strategies are needed to assist national decision makers, stakeholders, and

In vitro and in vivo evaluation of 28DAP010, a novel diamidine for treatment of second-stage African sleeping sickness.

PubMed

Wenzler, Tanja; Yang, Sihyung; Patrick, Donald A; Braissant, Olivier; Ismail, Mohamed A; Tidwell, Richard R; Boykin, David W; Wang, Michael Zhuo; Brun, Reto

2014-08-01

African sleeping sickness is a neglected tropical disease transmitted by tsetse flies. New and better drugs are still needed especially for its second stage, which is fatal if untreated. 28DAP010, a dipyridylbenzene analogue of DB829, is the second simple diamidine found to cure mice with central nervous system infections by a parenteral route of administration. 28DAP010 showed efficacy similar to that of DB829 in dose-response studies in mouse models of first- and second-stage African sleeping sickness. The in vitro time to kill, determined by microcalorimetry, and the parasite clearance time in mice were shorter for 28DAP010 than for DB829. No cross-resistance was observed between 28DAP010 and pentamidine on the tested Trypanosoma brucei gambiense isolates from melarsoprol-refractory patients. 28DAP010 is the second promising preclinical candidate among the diamidines for the treatment of second-stage African sleeping sickness. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

AFRICAN GENETIC DIVERSITY: Implications for Human Demographic History, Modern Human Origins, and Complex Disease Mapping

PubMed Central

Campbell, Michael C.; Tishkoff, Sarah A.

2010-01-01

Comparative studies of ethnically diverse human populations, particularly in Africa, are important for reconstructing human evolutionary history and for understanding the genetic basis of phenotypic adaptation and complex disease. African populations are characterized by greater levels of genetic diversity, extensive population substructure, and less linkage disequilibrium (LD) among loci compared to non-African populations. Africans also possess a number of genetic adaptations that have evolved in response to diverse climates and diets, as well as exposure to infectious disease. This review summarizes patterns and the evolutionary origins of genetic diversity present in African populations, as well as their implications for the mapping of complex traits, including disease susceptibility. PMID:18593304

False Positivity of Non-Targeted Infections in Malaria Rapid Diagnostic Tests: The Case of Human African Trypanosomiasis

PubMed Central

Gillet, Philippe; Mumba Ngoyi, Dieudonné; Lukuka, Albert; Kande, Viktor; Atua, Benjamin; van Griensven, Johan; Muyembe, Jean-Jacques; Jacobs, Jan; Lejon, Veerle

2013-01-01

Background In endemic settings, diagnosis of malaria increasingly relies on the use of rapid diagnostic tests (RDTs). False positivity of such RDTs is poorly documented, although it is especially relevant in those infections that resemble malaria, such as human African trypanosomiasis (HAT). We therefore examined specificity of malaria RDT products among patients infected with Trypanosoma brucei gambiense. Methodology/Principal Findings Blood samples of 117 HAT patients and 117 matched non-HAT controls were prospectively collected in the Democratic Republic of the Congo. Reference malaria diagnosis was based on real-time PCR. Ten commonly used malaria RDT products were assessed including three two-band and seven three-band products, targeting HRP-2, Pf-pLDH and/or pan-pLDH antigens. Rheumatoid factor was determined in PCR negative subjects. Specificity of the 10 malaria RDT products varied between 79.5 and 100% in HAT-negative controls and between 11.3 and 98.8% in HAT patients. For seven RDT products, specificity was significantly lower in HAT patients compared to controls. False positive reactions in HAT were mainly observed for pan-pLDH test lines (specificities between 13.8 and 97.5%), but also occurred frequently for the HRP-2 test line (specificities between 67.9 and 98.8%). The Pf-pLDH test line was not affected by false-positive lines in HAT patients (specificities between 97.5 and 100%). False positivity was not associated to rheumatoid factor, detected in 7.6% of controls and 1.2% of HAT patients. Conclusions/Significance Specificity of some malaria RDT products in HAT was surprisingly low, and constitutes a risk for misdiagnosis of a fatal but treatable infection. Our results show the importance to assess RDT specificity in non-targeted infections when evaluating diagnostic tests. PMID:23638201

Population genomics reveals the origin and asexual evolution of human infective trypanosomes

PubMed Central

Weir, William; Capewell, Paul; Foth, Bernardo; Clucas, Caroline; Pountain, Andrew; Steketee, Pieter; Veitch, Nicola; Koffi, Mathurin; De Meeûs, Thierry; Kaboré, Jacques; Camara, Mamadou; Cooper, Anneli; Tait, Andy; Jamonneau, Vincent; Bucheton, Bruno; Berriman, Matt; MacLeod, Annette

2016-01-01

Evolutionary theory predicts that the lack of recombination and chromosomal re-assortment in strictly asexual organisms results in homologous chromosomes irreversibly accumulating mutations and thus evolving independently of each other, a phenomenon termed the Meselson effect. We apply a population genomics approach to examine this effect in an important human pathogen, Trypanosoma brucei gambiense. We determine that T.b. gambiense is evolving strictly asexually and is derived from a single progenitor, which emerged within the last 10,000 years. We demonstrate the Meselson effect for the first time at the genome-wide level in any organism and show large regions of loss of heterozygosity, which we hypothesise to be a short-term compensatory mechanism for counteracting deleterious mutations. Our study sheds new light on the genomic and evolutionary consequences of strict asexuality, which this pathogen uses as it exploits a new biological niche, the human population. DOI: http://dx.doi.org/10.7554/eLife.11473.001 PMID:26809473

The impact of HIV/AIDS on human development in African countries.

PubMed

Boutayeb, Abdesslam

2009-11-18

In the present paper, we consider the impact of HIV/AIDS on human development in African countries, showing that, beyond health issues, this disease should and must be seen as a global development concern, affecting all components of human development. Consequently, we stress the necessity of multidisciplinary approaches that model, estimate and predict the real impact of HIV/AIDS on human development of African countries in order to optimise the strategies proposed by national countries, international institutions and their partners. In our search strategy, we relied on secondary information, mainly through National Human Development Reports of some African countries and regular publications released by the United Nations (UN), United Nations Development Programme (UNDP), World Health Organization (WHO) and the World Bank. We restricted ourselves to reports dealing explicitly with the impact of HIV/AIDS on human development in African countries. HIV/AIDS is affecting the global human development of African countries through its devastating impact on health and demographic indicators such as life expectancy at birth, healthcare assistance, age and sex distribution, economic indicators like income, work force, and economic growth, education and knowledge acquisition and other indicators like governance, gender inequality and human rights. On the basis of the national reports reviewed, it appears clearly that HIV/AIDS is no longer a crisis only for the healthcare sector, but presents a challenge to all sectors. Consequently, HIV/AIDS is a development question and should be viewed as such. The disease is impeding development by imposing a steady decline in the key indicators of human development and hence reversing the social and economic gains that African countries are striving to attain. Being at the same time a cause and consequence of poverty and underdevelopment, it constitutes a challenge to human security and human development by diminishing the chances of

African Trypanosomiasis

DTIC Science & Technology

2011-06-01

trypanosomes in the blood of a patient with Gambia fever and named the organisms T. gambiense. Two years later, Castellani found identical organisms...trypanosomes, and that Gambia fever and sleeping sickness were 2 stages of the same disease.5 In 1910, Stephens and Fantham identified trypanosomes in the...which parasites disseminate through the lymph nodes, lymphatic system, and bloodstream. Symptoms include fever , malaise, generalized rash, headache

Challenges towards the elimination of Human African Trypanosomiasis in the sleeping sickness focus of Campo in southern Cameroon.

PubMed

Simo, Gustave; Mbida Mbida, Jean Arthur; Ebo'o Eyenga, Vincent; Asonganyi, Tazoacha; Njiokou, Flobert; Grébaut, Pascal

2014-08-16

The sleeping sickness focus of Campo lies along the Atlantic coast and extends along the Ntem River, which constitutes the Cameroonian and Equatorial Guinean border. It is a hypo-endemic focus with the disease prevalence varying from 0.3 to 0.86% during the last few decades. Investigations on animal reservoirs revealed a prevalence of Trypanosoma brucei gambiense of 0.6% in wild animals and 4.83% in domestic animals of this focus. From 2001 to 2012, about 19 931 tsetse were collected in this focus and five tsetse species including Glossina palpalis palpalis, G. pallicera, G. nigrofusca, G. tabaniformis and G. caliginea were identified. The analysis of blood meals of these flies showed that they feed on human, pig, goat, sheep, and wild animals such as antelope, duiker, wild pig, turtle and snake. The percentage of blood meals taken on these hosts varies according to sampling periods. For instance, 6.8% of blood meals from pig were reported in 2004 and 22% in 2008. This variation is subjected to considerable evolutions because the Campo HAT focus is submitted to socio-economic mutations including the reopening of a new wood company, the construction of autonomous port at "Kribi" as well as the dam at "Memve ele". These activities will bring more that 3000 inhabitants around Campo and induce the deforestation for the implementation of farmlands as well as breeding of domestic animals. Such mutations have impacts on the transmission and the epidemiology of sleeping sickness due to the modification of the fauna composition, the nutritional behavior of tsetse, the zoophilic/anthropophilic index. To achieve the elimination goal in the sleeping sickness focus of Campo, we report in this paper the current epidemiological situation of the disease, the research findings of the last decades notably on the population genetics of trypanosomes, the modifications of nutritional behavior of tsetse, the prevalence of T. b. gambiense in humans, domestic and wild animals. An overview

Survey on Trypanosoma spp. infection of dogs in Gabon and its epidemiological implications for sleeping sickness.

PubMed

Watier-Grillot, S; Herder, S; Marié, J-L; Bourry, O; Cuny, G; Davoust, B

2016-05-01

This survey screened native dogs (Canis familiaris) in Gabon (Africa) for trypanosome infection. A total of 376 apparently healthy dogs, divided into two populations, were examined. The first group included 252 semi-domesticated dogs inhabiting 16 villages of the Ogooué-Ivindo Province, a rural inland area in northeast Gabon, and the second group 124 dogs belonging to protection companies or families from Libreville (n = 113) and Port-Gentil (n = 11), in the coastal area of Gabon. Both study areas include active or former foci of sleeping sickness in Gabon. Molecular testing (polymerase chain reaction) was performed on blood samples from dogs in both groups. All dogs were negative for T. congolense ("savanna type" and "forest type"). Eighteen dogs (4.7%), however, tested positive for T. brucei s.l.: 3% (8/252) were from the Ogooué-Ivindo Province, and 8% (10/124) from the coastal area. These animals may be potential reservoirs of the parasite T. brucei gambiense, responsible for human African trypanosomiasis. This hypothesis, as well as the role of the dog as a sentinel of human infection by T. brucei gambiense, should be investigated in further studies.

Molecular epidemiological studies on animal trypanosomiases in Ghana

PubMed Central

2012-01-01

Background African trypanosomes are extracellular protozoan parasites that are transmitted between mammalian hosts by the bite of an infected tsetse fly. Human African Trypanosomiasis (HAT) or sleeping sickness is caused by Trypanosoma brucei rhodesiense or T. brucei gambiense, while African Animal Trypanosomiasis (AAT) is caused mainly by T. vivax, T. congolense, T. simiae,T. evansi and T. brucei brucei. Trypanosomiasis is of public health importance in humans and is also the major constraint for livestock productivity in sub-Saharan African countries. Scanty information exists about the trypanosomiasis status in Ghana especially regarding molecular epidemiology. Therefore, this study intended to apply molecular tools to identify and characterize trypanosomes in Ghana. Methods A total of 219 tsetse flies, 248 pigs and 146 cattle blood samples were collected from Adidome and Koforidua regions in Ghana in 2010. Initial PCR assays were conducted using the internal transcribed spacer one (ITS1) of ribosomal DNA (rDNA) primers, which can detect most of the pathogenic trypanosome species and T. vivax-specific cathepsin L-like gene primers. In addition, species- or subgroup-specific PCRs were performed for T. b. rhodesiense, T. b. gambiense, T. evansi and three subgroups of T. congolense. Results The overall prevalence of trypanosomes were 17.4% (38/219), 57.5% (84/146) and 28.6% (71/248) in tsetse flies, cattle and pigs, respectively. T. congolense subgroup-specific PCR revealed that T. congolense Savannah (52.6%) and T. congolense Forest (66.0%) were the endemic subgroups in Ghana with 18.6% being mixed infections. T. evansi was detected in a single tsetse fly. Human infective trypanosomes were not detected in the tested samples. Conclusion Our results showed that there is a high prevalence of parasites in both tsetse flies and livestock in the study areas in Ghana. This enhances the need to strengthen control policies and institute measures that help prevent the

Diagnostic accuracy of PCR in gambiense sleeping sickness diagnosis, staging and post-treatment follow-up: a 2-year longitudinal study.

PubMed

Deborggraeve, Stijn; Lejon, Veerle; Ekangu, Rosine Ali; Mumba Ngoyi, Dieudonné; Pati Pyana, Patient; Ilunga, Médard; Mulunda, Jean Pierre; Büscher, Philippe

2011-02-22

The polymerase chain reaction (PCR) has been proposed for diagnosis, staging and post-treatment follow-up of sleeping sickness but no large-scale clinical evaluations of its diagnostic accuracy have taken place yet. An 18S ribosomal RNA gene targeting PCR was performed on blood and cerebrospinal fluid (CSF) of 360 T. brucei gambiense sleeping sickness patients and on blood of 129 endemic controls from the Democratic Republic of Congo. Sensitivity and specificity (with 95% confidence intervals) of PCR for diagnosis, disease staging and treatment failure over 2 years follow-up post-treatment were determined. Reference standard tests were trypanosome detection for diagnosis and trypanosome detection and/or increased white blood cell concentration in CSF for staging and detection of treatment failure. PCR on blood showed a sensitivity of 88.4% (84.4-92.5%) and a specificity of 99.2% (97.7-100%) for diagnosis, while for disease staging the sensitivity and specificity of PCR on cerebrospinal fluid were 88.4% (84.8-91.9%) and 82.9% (71.2-94.6%), respectively. During follow-up after treatment, PCR on blood had low sensitivity to detect treatment failure. In cerebrospinal fluid, PCR positivity vanished slowly and was observed until the end of the 2 year follow-up in around 20% of successfully treated patients. For T.b. gambiense sleeping sickness diagnosis and staging, PCR performed better than, or similar to, the current parasite detection techniques but it cannot be used for post-treatment follow-up. Continued PCR positivity in one out of five cured patients points to persistence of living or dead parasites or their DNA after successful treatment and may necessitate the revision of some paradigms about the pathophysiology of sleeping sickness.

Actigraphy in Human African Trypanosomiasis as a Tool for Objective Clinical Evaluation and Monitoring: A Pilot Study

PubMed Central

Njamnshi, Alfred K.; Seke Etet, Paul F.; Perrig, Stephen; Acho, Alphonse; Funsah, Julius Y.; Mumba, Dieudonné; Muyembe, Jean-Jacques; Kristensson, Krister; Bentivoglio, Marina

2012-01-01

Background Human African trypanosomiasis (HAT) or sleeping sickness leads to a complex neuropsychiatric syndrome with characteristic sleep alterations. Current division into a first, hemolymphatic stage and second, meningoencephalitic stage is primarily based on the detection of white blood cells and/or trypanosomes in the cerebrospinal fluid. The validity of this criterion is, however, debated, and novel laboratory biomarkers are under study. Objective clinical HAT evaluation and monitoring is therefore needed. Polysomnography has effectively documented sleep-wake disturbances during HAT, but could be difficult to apply as routine technology in field work. The non-invasive, cost-effective technique of actigraphy has been widely validated as a tool for the ambulatory evaluation of sleep disturbances. In this pilot study, actigraphy was applied to the clinical assessment of HAT patients. Methods/Principal Findings Actigraphy was recorded in patients infected by Trypanosoma brucei gambiense, and age- and sex-matched control subjects. Simultaneous nocturnal polysomnography was also performed in the patients. Nine patients, including one child, were analyzed at admission and two of them also during specific treatment. Parameters, analyzed with user-friendly software, included sleep time evaluated from rest-activity signals, rest-activity rhythm waveform and characteristics. The findings showed sleep-wake alterations of various degrees of severity, which in some patients did not parallel white blood cell counts in the cerebrospinal fluid. Actigraphic recording also showed improvement of the analyzed parameters after treatment initiation. Nocturnal polysomnography showed alterations of sleep time closely corresponding to those derived from actigraphy. Conclusions/Significance The data indicate that actigraphy can be an interesting tool for HAT evaluation, providing valuable clinical information through simple technology, well suited also for long-term follow

Trypanosoma brucei gambiense trypanosomiasis in Terego county, northern Uganda, 1996: a lot quality assurance sampling survey.

PubMed

Hutin, Yvan J F; Legros, Dominique; Owini, Vincent; Brown, Vincent; Lee, Evan; Mbulamberi, Dawson; Paquet, Christophe

2004-04-01

We estimated the pre-intervention prevalence of Trypanosoma brucei gambiense (Tbg) trypanosomiasis using the lot quality assurance sampling (LQAS) methods in 14 parishes of Terego County in northern Uganda. A total of 826 participants were included in the survey sample in 1996. The prevalence of laboratory confirmed Tbg trypanosomiasis adjusted for parish population sizes was 2.2% (95% confidence interval =1.1-3.2). This estimate was consistent with the 1.1% period prevalence calculated on the basis of cases identified through passive and active screening in 1996-1999. Ranking of parishes in four categories according to LQAS analysis of the 1996 survey predicted the prevalences observed during the first round of active screening in the population in 1997-1998 (P < 0.0001, by chi-square test). Overall prevalence and ranking of parishes obtained with LQAS were validated by the results of the population screening, suggesting that these survey methods may be useful in the pre-intervention phase of sleeping sickness control programs.

Recent African origin of modern humans revealed by complete sequences of hominoid mitochondrial DNAs.

PubMed Central

Horai, S; Hayasaka, K; Kondo, R; Tsugane, K; Takahata, N

1995-01-01

We analyzed the complete mitochondrial DNA (mtDNA) sequences of three humans (African, European, and Japanese), three African apes (common and pygmy chimpanzees, and gorilla), and one orangutan in an attempt to estimate most accurately the substitution rates and divergence times of hominoid mtDNAs. Nonsynonymous substitutions and substitutions in RNA genes have accumulated with an approximately clock-like regularity. From these substitutions and under the assumption that the orangutan and African apes diverged 13 million years ago, we obtained a divergence time for humans and chimpanzees of 4.9 million years. This divergence time permitted calibration of the synonymous substitution rate (3.89 x 10(-8)/site per year). To obtain the substitution rate in the displacement (D)-loop region, we compared the three human mtDNAs and measured the relative abundance of substitutions in the D-loop region and at synonymous sites. The estimated substitution rate in the D-loop region was 7.00 x 10(-8)/site per year. Using both synonymous and D-loop substitutions, we inferred the age of the last common ancestor of the human mtDNAs as 143,000 +/- 18,000 years. The shallow ancestry of human mtDNAs, together with the observation that the African sequence is the most diverged among humans, strongly supports the recent African origin of modern humans, Homo sapiens sapiens. PMID:7530363

Hunter-gatherer genomic diversity suggests a southern African origin for modern humans

PubMed Central

Henn, Brenna M.; Gignoux, Christopher R.; Jobin, Matthew; Granka, Julie M.; Macpherson, J. M.; Kidd, Jeffrey M.; Rodríguez-Botigué, Laura; Ramachandran, Sohini; Hon, Lawrence; Brisbin, Abra; Lin, Alice A.; Underhill, Peter A.; Comas, David; Kidd, Kenneth K.; Norman, Paul J.; Parham, Peter; Bustamante, Carlos D.; Mountain, Joanna L.; Feldman, Marcus W.

2011-01-01

Africa is inferred to be the continent of origin for all modern human populations, but the details of human prehistory and evolution in Africa remain largely obscure owing to the complex histories of hundreds of distinct populations. We present data for more than 580,000 SNPs for several hunter-gatherer populations: the Hadza and Sandawe of Tanzania, and the ≠Khomani Bushmen of South Africa, including speakers of the nearly extinct N|u language. We find that African hunter-gatherer populations today remain highly differentiated, encompassing major components of variation that are not found in other African populations. Hunter-gatherer populations also tend to have the lowest levels of genome-wide linkage disequilibrium among 27 African populations. We analyzed geographic patterns of linkage disequilibrium and population differentiation, as measured by FST, in Africa. The observed patterns are consistent with an origin of modern humans in southern Africa rather than eastern Africa, as is generally assumed. Additionally, genetic variation in African hunter-gatherer populations has been significantly affected by interaction with farmers and herders over the past 5,000 y, through both severe population bottlenecks and sex-biased migration. However, African hunter-gatherer populations continue to maintain the highest levels of genetic diversity in the world. PMID:21383195

Genome-wide association studies in Africans and African Americans: Expanding the Framework of the Genomics of Human Traits and Disease

PubMed Central

Peprah, Emmanuel; Xu, Huichun; Tekola-Ayele, Fasil; Royal, Charmaine D.

2014-01-01

Genomic research is one of the tools for elucidating the pathogenesis of diseases of global health relevance, and paving the research dimension to clinical and public health translation. Recent advances in genomic research and technologies have increased our understanding of human diseases, genes associated with these disorders, and the relevant mechanisms. Genome-wide association studies (GWAS) have proliferated since the first studies were published several years ago, and have become an important tool in helping researchers comprehend human variation and the role genetic variants play in disease. However, the need to expand the diversity of populations in GWAS has become increasingly apparent as new knowledge is gained about genetic variation. Inclusion of diverse populations in genomic studies is critical to a more complete understanding of human variation and elucidation of the underpinnings of complex diseases. In this review, we summarize the available data on GWAS in recent-African ancestry populations within the western hemisphere (i.e. African Americans and peoples of the Caribbean) and continental African populations. Furthermore, we highlight ways in which genomic studies in populations of recent African ancestry have led to advances in the areas of malaria, HIV, prostate cancer, and other diseases. Finally, we discuss the advantages of conducting GWAS in recent African ancestry populations in the context of addressing existing and emerging global health conditions. PMID:25427668

Escaping Deleterious Immune Response in Their Hosts: Lessons from Trypanosomatids

PubMed Central

Geiger, Anne; Bossard, Géraldine; Sereno, Denis; Pissarra, Joana; Lemesre, Jean-Loup; Vincendeau, Philippe; Holzmuller, Philippe

2016-01-01

The Trypanosomatidae family includes the genera Trypanosoma and Leishmania, protozoan parasites displaying complex digenetic life cycles requiring a vertebrate host and an insect vector. Trypanosoma brucei gambiense, Trypanosoma cruzi, and Leishmania spp. are important human pathogens causing human African trypanosomiasis (HAT or sleeping sickness), Chagas’ disease, and various clinical forms of Leishmaniasis, respectively. They are transmitted to humans by tsetse flies, triatomine bugs, or sandflies, and affect millions of people worldwide. In humans, extracellular African trypanosomes (T. brucei) evade the hosts’ immune defenses, allowing their transmission to the next host, via the tsetse vector. By contrast, T. cruzi and Leishmania sp. have developed a complex intracellular lifestyle, also preventing several mechanisms to circumvent the host’s immune response. This review seeks to set out the immune evasion strategies developed by the different trypanosomatids resulting from parasite–host interactions and will focus on: clinical and epidemiological importance of diseases; life cycles: parasites–hosts–vectors; innate immunity: key steps for trypanosomatids in invading hosts; deregulation of antigen-presenting cells; disruption of efficient specific immunity; and the immune responses used for parasite proliferation. PMID:27303406

Strengthening human genetics research in Africa: report of the 9th meeting of the African Society of Human Genetics in Dakar in May 2016.

PubMed

Ndiaye Diallo, R; Gadji, M; Hennig, B J; Guèye, M V; Gaye, A; Diop, J P D; Sylla Niang, M; Lopez Sall, P; Guèye, P M; Dem, A; Faye, O; Dieye, A; Cisse, A; Sembene, M; Ka, S; Diop, N; Williams, S M; Matovu, E; Ramesar, R S; Wonkam, A; Newport, M; Rotimi, C; Ramsay, M

2017-01-01

The 9th meeting of the African Society of Human Genetics, in partnership with the Senegalese Cancer Research and Study Group and the Human Heredity and Health in Africa (H3Africa) Consortium, was held in Dakar, Senegal. The theme was Strengthening Human Genetics Research in Africa. The 210 delegates came from 21 African countries and from France, Switzerland, UK, UAE, Canada and the USA. The goal was to highlight genetic and genomic science across the African continent with the ultimate goal of improving the health of Africans and those across the globe, and to promote the careers of young African scientists in the field. A session on the sustainability of genomic research in Africa brought to light innovative and practical approaches to supporting research in resource-limited settings and the importance of promoting genetics in academic, research funding, governmental and private sectors. This meeting led to the formation of the Senegalese Society for Human Genetics.

Evolution of the auditory ossicles in extant hominids: metric variation in African apes and humans.

PubMed

Quam, Rolf M; Coleman, Mark N; Martínez, Ignacio

2014-08-01

The auditory ossicles in primates have proven to be a reliable source of phylogenetic information. Nevertheless, to date, very little data have been published on the metric dimensions of the ear ossicles in African apes and humans. The present study relies on the largest samples of African ape ear ossicles studied to date to address questions of taxonomic differences and the evolutionary transformation of the ossicles in gorillas, chimpanzees and humans. Both African ape taxa show a malleus that is characterized by a long and slender manubrium and relatively short corpus, whereas humans show the opposite constellation of a short and thick manubrium and relatively long corpus. These changes in the manubrium are plausibly linked with changes in the size of the tympanic membrane. The main difference between the incus in African apes and humans seems to be related to changes in the functional length. Compared with chimpanzees, human incudes are larger in nearly all dimensions, except articular facet height, and show a more open angle between the axes. The gorilla incus resembles humans more closely in its metric dimensions, including functional length, perhaps as a result of the dramatically larger body size compared with chimpanzees. The differences between the stapedes of humans and African apes are primarily size-related, with humans being larger in nearly all dimensions. Nevertheless, some distinctions between the African apes were found in the obturator foramen and head height. Although correlations between metric variables in different ossicles were generally lower than those between variables in the same bone, variables of the malleus/incus complex appear to be more strongly correlated than those of the incus/stapes complex, perhaps reflecting the different embryological and evolutionary origins of the ossicles. The middle ear lever ratio for the African apes is similar to other haplorhines, but humans show the lowest lever ratio within primates. Very low levels

Evolution of the auditory ossicles in extant hominids: metric variation in African apes and humans

PubMed Central

Quam, Rolf M; Coleman, Mark N; Martínez, Ignacio

2014-01-01

The auditory ossicles in primates have proven to be a reliable source of phylogenetic information. Nevertheless, to date, very little data have been published on the metric dimensions of the ear ossicles in African apes and humans. The present study relies on the largest samples of African ape ear ossicles studied to date to address questions of taxonomic differences and the evolutionary transformation of the ossicles in gorillas, chimpanzees and humans. Both African ape taxa show a malleus that is characterized by a long and slender manubrium and relatively short corpus, whereas humans show the opposite constellation of a short and thick manubrium and relatively long corpus. These changes in the manubrium are plausibly linked with changes in the size of the tympanic membrane. The main difference between the incus in African apes and humans seems to be related to changes in the functional length. Compared with chimpanzees, human incudes are larger in nearly all dimensions, except articular facet height, and show a more open angle between the axes. The gorilla incus resembles humans more closely in its metric dimensions, including functional length, perhaps as a result of the dramatically larger body size compared with chimpanzees. The differences between the stapedes of humans and African apes are primarily size-related, with humans being larger in nearly all dimensions. Nevertheless, some distinctions between the African apes were found in the obturator foramen and head height. Although correlations between metric variables in different ossicles were generally lower than those between variables in the same bone, variables of the malleus/incus complex appear to be more strongly correlated than those of the incus/stapes complex, perhaps reflecting the different embryological and evolutionary origins of the ossicles. The middle ear lever ratio for the African apes is similar to other haplorhines, but humans show the lowest lever ratio within primates. Very low levels

Human impacts in African savannas are mediated by plant functional traits.

PubMed

Osborne, Colin P; Charles-Dominique, Tristan; Stevens, Nicola; Bond, William J; Midgley, Guy; Lehmann, Caroline E R

2018-05-28

Tropical savannas have a ground cover dominated by C 4 grasses, with fire and herbivory constraining woody cover below a rainfall-based potential. The savanna biome covers 50% of the African continent, encompassing diverse ecosystems that include densely wooded Miombo woodlands and Serengeti grasslands with scattered trees. African savannas provide water, grazing and browsing, food and fuel for tens of millions of people, and have a unique biodiversity that supports wildlife tourism. However, human impacts are causing widespread and accelerating degradation of savannas. The primary threats are land cover-change and transformation, landscape fragmentation that disrupts herbivore communities and fire regimes, climate change and rising atmospheric CO 2 . The interactions among these threats are poorly understood, with unknown consequences for ecosystem health and human livelihoods. We argue that the unique combinations of plant functional traits characterizing the major floristic assemblages of African savannas make them differentially susceptible and resilient to anthropogenic drivers of ecosystem change. Research must address how this functional diversity among African savannas differentially influences their vulnerability to global change and elucidate the mechanisms responsible. This knowledge will permit appropriate management strategies to be developed to maintain ecosystem integrity, biodiversity and livelihoods. © 2018 The Authors New Phytologist © 2018 New Phytologist Trust.

State obligations to implement African abortion laws: employing human rights in a changing legal landscape.

PubMed

Ngwena, Charles G

2012-11-01

Women in the African region are overburdened with unsafe abortion. Abortion regimes that fail to translate any given abortion rights into tangible access are partly to blame. Historically, African abortion laws have been highly restrictive. However, the post-independence era has witnessed a change toward liberalizing abortion law, even if incremental for many jurisdictions. Furthermore, Article 14 of the Protocol to the African Charter on Human and Peoples' Rights on the Rights of Women in Africa has significantly augmented the regional trend toward liberalization by recognizing abortion as a human right in given circumstances. However, states are failing to implement abortion laws. The jurisprudence that is emerging from the European Court of Human Rights and United Nations treaty bodies is a tool that can be used to render African governments accountable for failure to implement domestic abortion laws. Copyright © 2012 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

The vertebral formula of the last common ancestor of African apes and humans.

PubMed

McCollum, Melanie A; Rosenman, Burt A; Suwa, Gen; Meindl, Richard S; Lovejoy, C Owen

2010-03-15

The modal number of lumbar vertebrae in modern humans is five. It varies between three and four in extant African apes (mean=3.5). Because both chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla) possess the same distributions of thoracic, lumbar, and sacral vertebrae, it has been assumed from parsimony that the last common ancestor (LCA) of African apes and humans possessed a similarly short lower back. This "short-backed LCA" scenario has recently been viewed favorably in an analysis of the intra- and interspecific variation in axial formulas observed among African apes and humans (Pilbeam, 2004. J Exp Zool 302B:241-267). However, the number of bonobo (Pan paniscus) specimens in that study was small (N=17). Here we reconsider vertebral type and number in the LCA in light of an expanded P. paniscus sample as well as evidence provided by the human fossil record. The precaudal (pre-coccygeal) axial column of bonobos differs from those of chimpanzees and gorillas in displaying one additional vertebra as well as significantly different combinations of sacral, lumbar, and thoracic vertebrae. These findings, along with the six-segmented lumbar column of early Australopithecus and early Homo, suggest that the LCA possessed a long axial column and long lumbar spine and that reduction in the lumbar column occurred independently in humans and in each ape clade, and continued after separation of the two species of Pan as well. Such an explanation is strongly congruent with additional details of lumbar column reduction and lower back stabilization in African apes.

Preclinical Assessment of the Treatment of Second-Stage African Trypanosomiasis with Cordycepin and Deoxycoformycin

PubMed Central

Vodnala, Suman K.; Ferella, Marcela; Lundén-Miguel, Hilda; Betha, Evans; van Reet, Nick; Amin, Daniel Ndem; Öberg, Bo; Andersson, Björn; Kristensson, Krister; Wigzell, Hans; Rottenberg, Martin E.

2009-01-01

Background There is an urgent need to substitute the highly toxic compounds still in use for treatment of the encephalitic stage of human African trypanosomiasis (HAT). We here assessed the treatment with the doublet cordycepin and the deaminase inhibitor deoxycoformycin for this stage of infection with Trypanosoma brucei (T.b.). Methodology/Principal Findings Cordycepin was selected as the most efficient drug from a direct parasite viability screening of a compound library of nucleoside analogues. The minimal number of doses and concentrations of the drugs effective for treatment of T.b. brucei infections in mice were determined. Oral, intraperitoneal or subcutaneous administrations of the compounds were successful for treatment. The doublet was effective for treatment of late stage experimental infections with human pathogenic T.b. rhodesiense and T.b. gambiense isolates. Late stage infection treatment diminished the levels of inflammatory cytokines in brains of infected mice. Incubation with cordycepin resulted in programmed cell death followed by secondary necrosis of the parasites. T.b. brucei strains developed resistance to cordycepin after culture with increasing concentrations of the compound. However, cordycepin-resistant parasites showed diminished virulence and were not cross-resistant to other drugs used for treatment of HAT, i.e. pentamidine, suramin and melarsoprol. Although resistant parasites were mutated in the gene coding for P2 nucleoside adenosine transporter, P2 knockout trypanosomes showed no altered resistance to cordycepin, indicating that absence of the P2 transporter is not sufficient to render the trypanosomes resistant to the drug. Conclusions/Significance Altogether, our data strongly support testing of treatment with a combination of cordycepin and deoxycoformycin as an alternative for treatment of second-stage and/or melarsoprol-resistant HAT. PMID:19652702

Interpretation of human pointing by African elephants: generalisation and rationality.

PubMed

Smet, Anna F; Byrne, Richard W

2014-11-01

Factors influencing the abilities of different animals to use cooperative social cues from humans are still unclear, in spite of long-standing interest in the topic. One of the few species that have been found successful at using human pointing is the African elephant (Loxodonta africana); despite few opportunities for learning about pointing, elephants follow a pointing gesture in an object-choice task, even when the pointing signal and experimenter's body position are in conflict, and when the gesture itself is visually subtle. Here, we show that the success of captive African elephants at using human pointing is not restricted to situations where the pointing signal is sustained until the time of choice: elephants followed human pointing even when the pointing gesture was withdrawn before they had responded to it. Furthermore, elephants rapidly generalised their response to a type of social cue they were unlikely to have seen before: pointing with the foot. However, unlike young children, they showed no sign of evaluating the 'rationality' of this novel pointing gesture according to its visual context: that is, whether the experimenter's hands were occupied or not.

African human mtDNA phylogeography at-a-glance.

PubMed

Rosa, Alexandra; Brehem, António

2011-01-01

The mitochondrial DNA (mtDNA) genetic system has long proven to be useful for studying the demographic history of our species, since their proposed Southeast/East African origin 200 kya. Despite the weak archaeological and anthropologic records, which render a difficult understanding of early intra- continental migrations, the phylogenetic L0-L1'6 split at about 140-160 kya is thought to represent also an early sub-structuring of small and isolated communities in South and East Africa. Regional variation accumulated over the following millennia, with L2 and L3 lineages arising in Central and East Africa 100-75 kya. Their sub-Saharan dispersal not later than 60 kya, largely overwhelmed the L0'1 distribution, nowadays limited to South African Khoisan and Central African Pygmies. Cyclic expansions and retractions of the equatorial forest between 40 kya and the "Last Glacial Aridity Maximum" were able to reduce the genetic diversity of modern humans. Surviving regional-specific lineages have emerged from the Sahelian refuge areas, repopulating the region and contributing to the overall West African genetic similarity. Particular L1- L3 lineages mirror the substantial population growth made possible by moister and warmer conditions of the Sahara's Wet Phase and the adoption of agriculture and iron smelting techniques. The diffusion of the farming expertise from a Central African source towards South Africa was mediated by the Bantu people 3 kya. The strong impact of their gene flow almost erased the pre-existent maternal pool. Non-L mtDNAs testify for Eurasian lineages that have enriched the African maternal pool at different timeframes: i) Near and Middle Eastern influences in Upper Palaeolithic, probably link to the spread of Afro-Asiatic languages; ii) particular lineages from West Eurasia around or after the glacial period; iii) post-glacial mtDNA signatures from the Franco-Cantabrian refugia, that have crossed the Strait of Gibraltar and iv) Eurasian lineages

"Disappearance" and Feminist Research in the South African Academy of Humanities

ERIC Educational Resources Information Center

Bennett, Jane

2016-01-01

Following a global trend in humanities since the mid-1970s, South African humanities faculties began to include formal programmes in gender and sexualities studies from the mid-1990s on. While the immediate post-flag democratic era encouraged intellectual concentration on diverse questions of power and knowledge, the new century saw a decline in…

Health, Human Capital, and African American Migration Before 1910

PubMed Central

Logan, Trevon D.

2009-01-01

Using both IPUMS and the Colored Troops Sample of the Civil War Union Army Data, I estimate the effects of literacy and health on the migration propensities of African Americans from 1870 to 1910. I find that literacy and health shocks were strong predictors of migration and the stock of health was not. There were differential selection propensities based on slave status—former slaves were less likely to migrate given a specific health shock than free blacks. Counterfactuals suggest that as much as 35 percent of the difference in the mobility patterns of former slaves and free blacks is explained by differences in their human capital, and more than 20 percent of that difference is due to health alone. Overall, the selection effect of literacy on migration is reduced by one-tenth to one-third once health is controlled for. The low levels of human capital accumulation and rates of mobility for African Americans after the Civil War are partly explained by the poor health status of slaves and their immediate descendants. PMID:20161107

Not in wilderness: African vulture strongholds remain in areas with high human density

PubMed Central

Granadeiro, José Pedro; Monteiro, Hamilton; Nuno, Ana; Lecoq, Miguel; Cardoso, Paulo; Regalla, Aissa; Catry, Paulo

2018-01-01

Vultures constitute an important functional group in many ecosystems, providing crucial ecosystem services both in natural and humanized environments. These scavengers are facing massive declines worldwide, but in several African countries virtually nothing is known on populations’ status and threats, hampering the development of adequate conservation strategies. In Guinea-Bissau, globally important populations of Hooded Necrosyrtes monachus and African white-backed vultures Gyps africanus were recently reported. Using the country as a study area, we aim to characterize human-vulture interactions in West Africa applying a multidisciplinary approach. We assessed the status and distribution of vulture populations using data from 1711 km of roadside transects, examined predictors of their distribution, and produced a nationwide population estimate for the Hooded Vulture, using an innovative method based on the relationship between the size of human population in settlements and vulture numbers. We conducted 47 stakeholder interviews to assess perceived roles played by vultures, and to investigate potential anthropogenic threats. Hooded vultures were strongly associated with high human population densities, whereas no relation was found between African white-backed and Rüppell’s vultures and any of the tested predictors, which included cattle density, precipitation and Normalized Difference Vegetation Index, among others. We estimate a national population of 43347 Hooded vultures, the largest population reported in the species range. Respondents were generally aware of the services provided by vultures, especially waste and carcass removal, including in urban areas. Hunting for witchcraft and traditional medicine was the most frequently recognised threat, while poisoning was ranked as having the highest impact. We hypothesise that poisoning-related mortality may be affecting African white-backed and Rüppell’s vultures’ distribution and explain their scarcity

Not in wilderness: African vulture strongholds remain in areas with high human density.

PubMed

Henriques, Mohamed; Granadeiro, José Pedro; Monteiro, Hamilton; Nuno, Ana; Lecoq, Miguel; Cardoso, Paulo; Regalla, Aissa; Catry, Paulo

2018-01-01

Vultures constitute an important functional group in many ecosystems, providing crucial ecosystem services both in natural and humanized environments. These scavengers are facing massive declines worldwide, but in several African countries virtually nothing is known on populations' status and threats, hampering the development of adequate conservation strategies. In Guinea-Bissau, globally important populations of Hooded Necrosyrtes monachus and African white-backed vultures Gyps africanus were recently reported. Using the country as a study area, we aim to characterize human-vulture interactions in West Africa applying a multidisciplinary approach. We assessed the status and distribution of vulture populations using data from 1711 km of roadside transects, examined predictors of their distribution, and produced a nationwide population estimate for the Hooded Vulture, using an innovative method based on the relationship between the size of human population in settlements and vulture numbers. We conducted 47 stakeholder interviews to assess perceived roles played by vultures, and to investigate potential anthropogenic threats. Hooded vultures were strongly associated with high human population densities, whereas no relation was found between African white-backed and Rüppell's vultures and any of the tested predictors, which included cattle density, precipitation and Normalized Difference Vegetation Index, among others. We estimate a national population of 43347 Hooded vultures, the largest population reported in the species range. Respondents were generally aware of the services provided by vultures, especially waste and carcass removal, including in urban areas. Hunting for witchcraft and traditional medicine was the most frequently recognised threat, while poisoning was ranked as having the highest impact. We hypothesise that poisoning-related mortality may be affecting African white-backed and Rüppell's vultures' distribution and explain their scarcity in

Decoding the network of Trypanosoma brucei proteins that determines sensitivity to apolipoprotein-L1

PubMed Central

MacLeod, Annette

2018-01-01

In contrast to Trypanosoma brucei gambiense and T. b. rhodesiense (the causative agents of human African trypanosomiasis), T. b. brucei is lysed by apolipoprotein-L1 (apoL1)-containing human serum trypanolytic factors (TLF), rendering it non-infectious to humans. While the mechanisms of TLF1 uptake, apoL1 membrane integration, and T. b. gambiense and T. b. rhodesiense apoL1-resistance have been extensively characterised, our understanding of the range of factors that drive apoL1 action in T. b. brucei is limited. Selecting our bloodstream-form T. b. brucei RNAi library with recombinant apoL1 identified an array of factors that supports the trypanocidal action of apoL1, including six putative ubiquitin modifiers and several proteins putatively involved in membrane trafficking; we also identified the known apoL1 sensitivity determinants, TbKIFC1 and the V-ATPase. Most prominent amongst the novel apoL1 sensitivity determinants was a putative ubiquitin ligase. Intriguingly, while loss of this ubiquitin ligase reduces parasite sensitivity to apoL1, its loss enhances parasite sensitivity to TLF1-dominated normal human serum, indicating that free and TLF1-bound apoL1 have contrasting modes-of-action. Indeed, loss of the known human serum sensitivity determinants, p67 (lysosomal associated membrane protein) and the cathepsin-L regulator, ‘inhibitor of cysteine peptidase’, had no effect on sensitivity to free apoL1. Our findings highlight a complex network of proteins that influences apoL1 action, with implications for our understanding of the anti-trypanosomal action of human serum. PMID:29346416

RNA-seq de novo Assembly Reveals Differential Gene Expression in Glossina palpalis gambiensis Infected with Trypanosoma brucei gambiense vs. Non-Infected and Self-Cured Flies

PubMed Central

Hamidou Soumana, Illiassou; Klopp, Christophe; Ravel, Sophie; Nabihoudine, Ibouniyamine; Tchicaya, Bernadette; Parrinello, Hugues; Abate, Luc; Rialle, Stéphanie; Geiger, Anne

2015-01-01

Trypanosoma brucei gambiense (Tbg), causing the sleeping sickness chronic form, completes its developmental cycle within the tsetse fly vector Glossina palpalis gambiensis (Gpg) before its transmission to humans. Within the framework of an anti-vector disease control strategy, a global gene expression profiling of trypanosome infected (susceptible), non-infected, and self-cured (refractory) tsetse flies was performed, on their midguts, to determine differential genes expression resulting from in vivo trypanosomes, tsetse flies (and their microbiome) interactions. An RNAseq de novo assembly was achieved. The assembled transcripts were mapped to reference sequences for functional annotation. Twenty-four percent of the 16,936 contigs could not be annotated, possibly representing untranslated mRNA regions, or Gpg- or Tbg-specific ORFs. The remaining contigs were classified into 65 functional groups. Only a few transposable elements were present in the Gpg midgut transcriptome, which may represent active transpositions and play regulatory roles. One thousand three hundred and seventy three genes differentially expressed (DEGs) between stimulated and non-stimulated flies were identified at day-3 post-feeding; 52 and 1025 between infected and self-cured flies at 10 and 20 days post-feeding, respectively. The possible roles of several DEGs regarding fly susceptibility and refractoriness are discussed. The results provide new means to decipher fly infection mechanisms, crucial to develop anti-vector control strategies. PMID:26617594

Factors influencing passive surveillance for T. b. rhodesiense human african trypanosomiasis in Uganda.

PubMed

Acup, Christine; Bardosh, Kevin Louis; Picozzi, Kim; Waiswa, Charles; Welburn, Susan Christina

2017-01-01

Sleeping sickness or Human African Trypanosomiasis (HAT) is a neglected tropical disease of public health importance across much of Sub-Saharan Africa. In Uganda, chronic T. b. gambiense HAT (gHAT) and acute T. b. rhodesiense HAT (rHAT) occur in two large but discrete geographical foci. Both forms are difficult to diagnose, expensive to treat and ultimately fatal in the absence of treatment. The area affected by zoonotic rHAT has been steadily expanding, placing a high burden on local health systems. HAT is a disease of neglected populations and is notorious for being under-reported. Here we examine the factors that influence passive rHAT surveillance within the district health system in four Ugandan districts into which the disease had recently been introduced, focusing on staff knowledge, infrastructure and data management. A mixed methods study was undertaken between 2011 and 2013 in Dokolo, Kaberamaido, Soroti and Serere districts to explore health facility capacity and clinical service provision, diagnostic capacity, HAT knowledge and case reporting. Structured interviews were undertaken with 86 medical personnel, including clinicians, nurses, midwives and technicians across 65 HC-II and HC-III medical facilities, where the health infrastructure was also directly observed. Eleven semi-structured interviews were undertaken with medical staff in each of the three designated HAT treatment facilities (Dokolo, Lwala and Serere HC-IV) in the area. HAT treatment centre case records, collected between 2009 and 2012, were analyzed. Most medical staff in HC-II and HC-III facilities had been made aware of HAT from radio broadcasts, newspapers and by word of mouth, suggestive of a lack of formal training. Key knowledge as regards the causative agent, clinical signs and that HAT drugs are provided free of charge was lower amongst HC-II than HC-III staff. Many respondents did not know whether HAT was endemic in their district. In rHAT specialist treatment centres, staff

Influence of source and quantity of protein on the development of immunity and resistance to African trypanosomiasis.

PubMed Central

Norton, J D; Yang, S P; Diffley, P

1986-01-01

Although it is well documented that severe protein deprivation inhibits the development of the immune response and exacerbates certain infections, little has been done to study the effects of native diets on endemic diseases or immunity. Therefore, protein-restricted diets were formulated for mice to mimic the sources and amounts measured in human diets of the Batouri region of Cameroon, endemic for African trypanosomiasis. Weanling C57BL/6 female mice were fed a diet that contained 73% of the recommended daily allowance (RDA) of protein. The sources of protein were all plant (cornmeal), all animal (casein), or a ratio that reflected the native diet (2.2 parts plant to 1 part animal protein). Diets were isocaloric on a weight basis, equal in lipids, and adequate in vitamins and minerals. Control mice were fed laboratory chow or two times the RDA of animal protein (casein). Mice fed only cornmeal or the native diets consumed as much food but did not gain as much weight as mice fed only animal protein, indicating the poorer quality of protein in their diets. Upon infection with Trypanosoma brucei gambiense, however, significantly higher numbers of these mice controlled the first peak of parasitemia and survived the infection as compared with mice fed the other three diets. Since all mice developed patent infections and the parasite growth rate was unaffected by diet, innate immune factors were ruled out as the cause for the higher level of resistance to the parasite. To determine whether diet affected the development of the immune system, weanling mice were maintained on diets for 30 days before immunization with sheep erythrocytes or trinitrophenylated Ficoll. Mice fed only plant protein or native diets elicited higher direct plaque-forming-cell responses to both the T-cell-dependent and T-cell-independent antigens. Since variant-specific immunity which controls levels of African trypanosomes in the blood is a T-cell-independent humoral immunoglobulin M response

Human trypanolytic factor APOL1 forms pH-gated cation-selective channels in planar lipid bilayers: Relevance to trypanosome lysis

PubMed Central

Thomson, Russell; Finkelstein, Alan

2015-01-01

Apolipoprotein L-1 (APOL1), the trypanolytic factor of human serum, can lyse several African trypanosome species including Trypanosoma brucei brucei, but not the human-infective pathogens T. brucei rhodesiense and T. brucei gambiense, which are resistant to lysis by human serum. Lysis follows the uptake of APOL1 into acidic endosomes and is apparently caused by colloid-osmotic swelling due to an increased ion permeability of the plasma membrane. Here we demonstrate that nanogram quantities of full-length recombinant APOL1 induce ideally cation-selective macroscopic conductances in planar lipid bilayers. The conductances were highly sensitive to pH: their induction required acidic pH (pH 5.3), but their magnitude could be increased 3,000-fold upon alkalinization of the milieu (pKa = 7.1). We show that this phenomenon can be attributed to the association of APOL1 with the bilayer at acidic pH, followed by the opening of APOL1-induced cation-selective channels upon pH neutralization. Furthermore, the conductance increase at neutral pH (but not membrane association at acidic pH) was prevented by the interaction of APOL1 with the serum resistance-associated protein, which is produced by T. brucei rhodesiense and prevents trypanosome lysis by APOL1. These data are consistent with a model of lysis that involves endocytic recycling of APOL1 and the formation of cation-selective channels, at neutral pH, in the parasite plasma membrane. PMID:25730870

Size and form of the human temporomandibular joint in African-Americans and Caucasians.

PubMed

Magnusson, Cecilia; Magnusson, Tomas

2012-04-01

The aim of this study was to examine contemporary human skull material for possible differences between Caucasians and African-Americans in respect to size and form of the temporomandibular condyles. The material consisted of a total of 129 Caucasian skulls (94 males and 35 females) and 76 African-American skulls (40 males and 36 females). Their mean age at death was 46 years for the Caucasians (range: 19-89 years) and 37 years for the African-Americans (range: 18-70 years). The mediolateral and anteroposterior dimensions of the 410 condyles were measured, and the condylar form was estimated using both anterior and superior views. No statistically significant differences could be found between Caucasians and African-Americans for any of the recorded variables. In conclusion, the present results lend no support for the existence of ethnic differences between the two groups examined in respect of temporomandibular joint size and form. It is likely that other factors such as evolution, overall cranial size, dietary differences, and genetic factors, irrespective of ethnicity, can explain the differences found in different skull samples.

The episode of genetic drift defining the migration of humans out of Africa is derived from a large east African population size.

PubMed

Elhassan, Nuha; Gebremeskel, Eyoab Iyasu; Elnour, Mohamed Ali; Isabirye, Dan; Okello, John; Hussien, Ayman; Kwiatksowski, Dominic; Hirbo, Jibril; Tishkoff, Sara; Ibrahim, Muntaser E

2014-01-01

Human genetic variation particularly in Africa is still poorly understood. This is despite a consensus on the large African effective population size compared to populations from other continents. Based on sequencing of the mitochondrial Cytochrome C Oxidase subunit II (MT-CO2), and genome wide microsatellite data we observe evidence suggesting the effective size (Ne) of humans to be larger than the current estimates, with a foci of increased genetic diversity in east Africa, and a population size of east Africans being at least 2-6 fold larger than other populations. Both phylogenetic and network analysis indicate that east Africans possess more ancestral lineages in comparison to various continental populations placing them at the root of the human evolutionary tree. Our results also affirm east Africa as the likely spot from which migration towards Asia has taken place. The study reflects the spectacular level of sequence variation within east Africans in comparison to the global sample, and appeals for further studies that may contribute towards filling the existing gaps in the database. The implication of these data to current genomic research, as well as the need to carry out defined studies of human genetic variation that includes more African populations; particularly east Africans is paramount.

Identification of different trypanosome species in the mid-guts of tsetse flies of the Malanga (Kimpese) sleeping sickness focus of the Democratic Republic of Congo.

PubMed

Simo, Gustave; Silatsa, Barberine; Flobert, Njiokou; Lutumba, Pascal; Mansinsa, Philemon; Madinga, Joule; Manzambi, Emile; De Deken, Reginald; Asonganyi, Tazoacha

2012-09-19

The Malanga sleeping sickness focus of the Democratic Republic of Congo has shown an epidemic evolution of disease during the last century. However, following case detection and treatment, the prevalence of the disease decreased considerably. No active survey has been undertaken in this focus for a couple of years. To understand the current epidemiological status of sleeping sickness as well as the animal African trypanosomiasis in the Malanga focus, we undertook the identification of tsetse blood meals as well as different trypanosome species in flies trapped in this focus. Pyramidal traps were use to trap tsetse flies. All flies caught were identified and live flies were dissected and their mid-guts collected. Fly mid-gut was used for the molecular identification of the blood meal source, as well as for the presence of different trypanosome species. About 949 Glossina palpalis palpalis were trapped; 296 (31.2%) of which were dissected, 60 (20.3%) blood meals collected and 57 (19.3%) trypanosome infections identified. The infection rates were 13.4%, 5.1%, 3.5% and 0.4% for Trypanosoma congolense savannah type, Trypanosoma brucei s.l., Trypanosoma congolense forest type and Trypanosoma vivax, respectively. Three mixed infections including Trypanosoma brucei s.l. and Trypanosoma congolense savannah type, and one mixed infection of Trypanosoma vivax and Trypanosoma congolense savannah type were identified. Eleven Trypanosoma brucei gambiense infections were identified; indicating an active circulation of this trypanosome subspecies. Of all the identified blood meals, about 58.3% were identified as being taken on pigs, while 33.3% and 8.3% were from man and other mammals, respectively. The presence of Trypanosoma brucei in tsetse mid-guts associated with human blood meals is indicative of an active transmission of this parasite between tsetse and man. The considerable number of pig blood meals combined with the circulation of Trypanosoma brucei gambiense in this focus

Identifying Darwinian selection acting on different human APOL1 variants among diverse African populations.

PubMed

Ko, Wen-Ya; Rajan, Prianka; Gomez, Felicia; Scheinfeldt, Laura; An, Ping; Winkler, Cheryl A; Froment, Alain; Nyambo, Thomas B; Omar, Sabah A; Wambebe, Charles; Ranciaro, Alessia; Hirbo, Jibril B; Tishkoff, Sarah A

2013-07-11

Disease susceptibility can arise as a consequence of adaptation to infectious disease. Recent findings have suggested that higher rates of chronic kidney disease (CKD) in individuals with recent African ancestry might be attributed to two risk alleles (G1 and G2) at the serum-resistance-associated (SRA)-interacting-domain-encoding region of APOL1. These two alleles appear to have arisen adaptively, possibly as a result of their protective effects against human African trypanosomiasis (HAT), or African sleeping sickness. In order to explore the distribution of potential functional variation at APOL1, we studied nucleotide variation in 187 individuals across ten geographically and genetically diverse African ethnic groups with exposure to two Trypanosoma brucei subspecies that cause HAT. We observed unusually high levels of nonsynonymous polymorphism in the regions encoding the functional domains that are required for lysing parasites. Whereas allele frequencies of G2 were similar across all populations (3%-8%), the G1 allele was only common in the Yoruba (39%). Additionally, we identified a haplotype (termed G3) that contains a nonsynonymous change at the membrane-addressing-domain-encoding region of APOL1 and is present in all populations except for the Yoruba. Analyses of long-range patterns of linkage disequilibrium indicate evidence of recent selection acting on the G3 haplotype in Fulani from Cameroon. Our results indicate that the G1 and G2 variants in APOL1 are geographically restricted and that there might be other functional variants that could play a role in HAT resistance and CKD risk in African populations. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Phylogenetic relations of humans and African apes from DNA sequences in the Psi eta-globin region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyamoto, M.M.; Slightom, J.L.; Goodman, M.

Sequences from the upstream and downstream flanking DNA regions of the Psi eta-globin locus in Pan troglodytes (common chimpanzee), Gorilla gorilla (gorilla), and Pongo pygmaeus (orangutan, the closest living relative to Homo, Pan, and Gorilla) provided further data for evaluating the phylogenetic relations of humans and African apes. These newly sequenced orthologs (an additional 4.9 kilobase pairs (kbp) for each species) were combined with published Psi eta-gene sequences and then compared to the same orthologous stretch (a continuous 7.1-kbp region) available for humans. Phylogenetic analysis of these nucleotide sequences by the parsimony method indicated (i) that human and chimpanzee aremore » more closely related to each other than either is to gorilla and (ii) that the slowdown in the rate of sequence evolution evident in higher primates is especially pronounced in humans. These results indicate that features unique to African apes (but not to humans) are primitive and that even local molecular clocks should be applied with caution.« less

Historical perspective and human consequences of Africanized bee stings in the Americas.

PubMed

Ferreira, R S; Almeida, R A M B; Barraviera, S R C S; Barraviera, B

2012-01-01

In 1956, Africanized bees began to spread in the American continent from southern Brazil, where original African bees mated with European bees. A few years later, in 1990, these Africanized bees reached the United States and were found in Texas. Currently, these hybrid bees are found in several North American states and will probably reach the Canadian border in the future. Although the presence of Africanized bees had produced positive effects on Brazilian economy, including improvement in crop pollination and in honey production, turning Brazil into a major exporter, the negative impacts-such as swarming, aggressive behavior, and the ability to mass attack-resulted in serious and fatal envenomation with humans and animals. Victims of bee attacks usually develop a severe envenomation syndrome characterized by the release of a large amount of cytokines [interleukins (IL) IL-1, IL-6, IL-8], and tumor necrosis factor (TNF). Subsequently, such cytokines produce an acute inflammatory response that triggers adverse effects on skeletal muscles; bone marrow; hepatic and renal functions; and cardiovascular, central nervous, and immune systems. Finally, the aim of the present review is to study historical characteristics and current status of Africanized bees' spread, the composition of their venom, the impact of the bees on the Brazilian economy and ecology, and clinical aspects of their stings including immune response, and to suggest a protocol for bee sting management since there is no safe and effective antivenom available.

Improved analyses of human mtDNA sequences support a recent African origin for Homo sapiens.

PubMed

Penny, D; Steel, M; Waddell, P J; Hendy, M D

1995-09-01

New quantitative methods are applied to the 135 human mitochondrial sequences from the Vigilant et al. data set. General problems in analyzing large numbers of short sequences are discussed, and an improved strategy is suggested. A key feature is to focus not on individual trees but on the general "landscape" of trees. Over 1,000 searches were made from random starting trees with only one tree (a local optimum) being retained each time, thereby ensuring optima were found independently. A new tree comparison metric was developed that is unaffected by rearrangements of trees around many very short internal edges. Use of this metric showed that downweighting hypervariable sites revealed more evolutionary structure than studies that weighted all sites equally. Our results are consistent with convergence toward a global optimum. Crucial features are that the best optima show very strong regional differentiation, a common group of 49 African sequences is found in all the best optima, and the best optima contain the 16 !Kung sequences in a separate group of San people. The other 86 sequences form a heterogeneous mixture of Africans, Europeans, Australopapuans, and Asians. Thus all major human lineages occur in Africa, but only a subset occurs in the rest of the world. The existence of these African-only groups strongly contradicts multiregional theories for the origin of Homo sapiens that require widespread migration and interbreeding over the entire range of H. erectus. Only when the multiregional model is rejected is it appropriate to consider the root, based on a single locus, to be the center of origin of a population (otherwise different loci could give alternative geographic positions for the root). For this data, several methods locate the root within the group of 49 African sequences and are thus consistent with the recent African origin of H. sapiens. We demonstrate that the time of the last common ancestor cannot be the time of major expansion in human numbers

Impact of the Ebola outbreak on Trypanosoma brucei gambiense infection medical activities in coastal Guinea, 2014-2015: A retrospective analysis from the Guinean national Human African Trypanosomiasis control program.

PubMed

Camara, Mariame; Ouattara, Eric; Duvignaud, Alexandre; Migliani, René; Camara, Oumou; Leno, Mamadou; Solano, Philippe; Bucheton, Bruno; Camara, Mamadou; Malvy, Denis

2017-11-01

The 2014-2015 Ebola outbreak massively hit Guinea. The coastal districts of Boffa, Dubreka and Forecariah, three major foci of Human African Trypanosomiasis (HAT), were particularly affected. We aimed to assess the impact of this epidemic on sleeping sickness screening and caring activities. We used preexisting data from the Guinean sleeping sickness control program, collected between 2012 and 2015. We described monthly: the number of persons (i) screened actively; (ii) or passively; (iii) treated for HAT; (iv) attending post-treatment follow-up visits. We compared clinical data, treatment characteristics and Disability Adjusted Life-Years (DALYs) before (February 2012 to December 2013) and during (January 2014 to October 2015) the Ebola outbreak period according to available data. Whereas 32,221 persons were actively screened from February 2012 to December 2013, before the official declaration of the first Ebola case in Guinea, no active screening campaigns could be performed during the Ebola outbreak. Following the reinforcement and extension of HAT passive surveillance system early in 2014, the number of persons tested passively by month increased from 7 to 286 between April and September 2014 and then abruptly decreased to 180 until January 2015 and to none after March 2015. 213 patients initiated HAT treatment, 154 (72%) before Ebola and 59 (28%) during the Ebola outbreak. Those initiating HAT therapy during Ebola outbreak were recruited through passive screening and diagnosed at a later stage 2 of the disease (96% vs. 55% before Ebola, p<0.0001). The proportion of patients attending the 3 months and 6 months post-treatment follow-up visits decreased from 44% to 10% (p <0.0001) and from 16% to 3% (p = 0.017) respectively. The DALYs generated before the Ebola outbreak were estimated to 48.7 (46.7-51.5) and increased up to 168.7 (162.7-174.7), 284.9 (277.1-292.8) and 466.3 (455.7-477.0) during Ebola assuming case fatality rates of 2%, 5% and 10% respectively

Bilateral asymmetry of humeral torsion and length in African apes and humans.

PubMed

Barros, Anna; Soligo, Christophe

2013-01-01

Few studies have directly compared human and African ape upper limb skeletal asymmetries despite the potential such comparisons have for understanding the origins of functional lateralization in humans and non-human primates. Here, we report the magnitude and direction of asymmetries in humeral torsion and humeral length in paired humeri of 40 Gorilla gorilla, 40 Pan troglodytes and 40 Homo sapiens. We test whether absolute and directional asymmetries differ between measurements, species and sexes. Our results show that humans are unique in being lateralized to the right for both measurements, consistent with human population-level handedness patterns, while apes show no significant directionality at the species level in either measurement. However, absolute torsion asymmetries in apes occur in the same magnitude as in humans, suggesting the existence of functional lateralization at the individual level. Copyright © 2013 S. Karger AG, Basel

South African Educators' Mutually Inclusive Mandates to Promote Human Rights and Positive Discipline

ERIC Educational Resources Information Center

Coetzee, Susan; Mienie, Cathrine

2013-01-01

South African educators are mandated by international and national law to observe and promote human rights. However, given the realities of the limited teaching time available, educators cannot fulfill this obligation solely by teaching the curriculum. Another avenue needs to be found for educators to fulfill this obligation. Educators are also…

Molecular recognition of human ephrinB2 cell surface receptor by an emergent African henipavirus

PubMed Central

Lee, Benhur; Pernet, Olivier; Ahmed, Asim A.; Zeltina, Antra; Beaty, Shannon M.; Bowden, Thomas A.

2015-01-01

The discovery of African henipaviruses (HNVs) related to pathogenic Hendra virus (HeV) and Nipah virus (NiV) from Southeast Asia and Australia presents an open-ended health risk. Cell receptor use by emerging African HNVs at the stage of host-cell entry is a key parameter when considering the potential for spillover and infection of human populations. The attachment glycoprotein from a Ghanaian bat isolate (GhV-G) exhibits <30% sequence identity with Asiatic NiV-G/HeV-G. Here, through functional and structural analysis of GhV-G, we show how this African HNV targets the same human cell-surface receptor (ephrinB2) as the Asiatic HNVs. We first characterized this virus−receptor interaction crystallographically. Compared with extant HNV-G–ephrinB2 structures, there was significant structural variation in the six-bladed β-propeller scaffold of the GhV-G receptor-binding domain, but not the Greek key fold of the bound ephrinB2. Analysis revealed a surprisingly conserved mode of ephrinB2 interaction that reflects an ongoing evolutionary constraint among geographically distal and phylogenetically divergent HNVs to maintain the functionality of ephrinB2 recognition during virus–host entry. Interestingly, unlike NiV-G/HeV-G, we could not detect binding of GhV-G to ephrinB3. Comparative structure–function analysis further revealed several distinguishing features of HNV-G function: a secondary ephrinB2 interaction site that contributes to more efficient ephrinB2-mediated entry in NiV-G relative to GhV-G and cognate residues at the very C terminus of GhV-G (absent in Asiatic HNV-Gs) that are vital for efficient receptor-induced fusion, but not receptor binding per se. These data provide molecular-level details for evaluating the likelihood of African HNVs to spill over into human populations. PMID:25825759

Substituted 2-Phenyl-Imidazopyridines: A New Class of Drug Leads for Human African Trypanosomiasis

PubMed Central

Tatipaka, Hari Babu; Gillespie, J. Robert; Chatterjee, Arnab K.; Norcross, Neil R.; Hulverson, Matthew A.; Ranade, Ranae M.; Nagendar, Pendem; Creason, Sharon A.; McQueen, Joshua; Duster, Nicole A.; Nagle, Advait; Supek, Frantisek; Molteni, Valentina; Wenzler, Tanja; Brun, Reto; Glynne, Richard; Buckner, Frederick S.; Gelb, Michael H.

2014-01-01

A phenotypic screen of a compound library for antiparasitic activity on Trypanosoma brucei, the causative agent of human African trypanosomiasis, led to the identification of substituted 2-(3-aminophenyl) oxazolopyridines as a starting point for hit-to-lead medicinal chemistry. A total of 110 analogues were prepared, which led to the identification of 64, a substituted 2-(3-aminophenyl) imidazopyridine. This compound showed antiparasitic activity in vitro with an EC50 of 2 nM and displayed reasonable drug-like properties when tested in a number of in vitro assays. The compound was orally bioavailable and displayed good plasma and brain exposure in mice. Compound 64 cured mice infected with Trypanosoma brucei when dosed orally down to 2.5 mg/kg. Given its potent anti-parasitic properties and its ease of synthesis, compound 64 represents a new lead for the development of drugs to treat human African trypanosomiasis. PMID:24354316

African leaders' views on critical human resource issues for the implementation of family medicine in Africa.

PubMed

Moosa, Shabir; Downing, Raymond; Essuman, Akye; Pentz, Stephen; Reid, Stephen; Mash, Robert

2014-01-17

The World Health Organisation has advocated for comprehensive primary care teams, which include family physicians. However, despite (or because of) severe doctor shortages in Africa, there is insufficient clarity on the role of the family physician in the primary health care team. Instead there is a trend towards task shifting without thought for teamwork, which runs the risk of dangerous oversimplification. It is not clear how African leaders understand the challenges of implementing family medicine, especially in human resource terms. This study, therefore, sought to explore the views of academic and government leaders on critical human resource issues for implementation of family medicine in Africa. In this qualitative study, key academic and government leaders were purposively selected from sixteen African countries. In-depth interviews were conducted using an interview guide. All interviews were audio-recorded, transcribed and thematically analysed. There were 27 interviews conducted with 16 government and 11 academic leaders in nine Sub-Saharan African countries: Botswana, Democratic Republic of Congo, Ghana, Kenya, Malawi, Nigeria, Rwanda, South Africa and Uganda. Respondents spoke about: educating doctors in family medicine suited to Africa, including procedural skills and holistic care, to address the difficulty of recruiting and retaining doctors in rural and underserved areas; planning for primary health care teams, including family physicians; new supervisory models in primary health care; and general human resource management issues. Important milestones in African health care fail to specifically address the human resource issues of integrated primary health care teamwork that includes family physicians. Leaders interviewed in this study, however, proposed organising the district health system with a strong embrace of family medicine in Africa, especially with regard to providing clinical leadership in team-based primary health care. Whilst these

Infusing Human Rights into the Curriculum: The Case of the South African Revised National Curriculum Statement

ERIC Educational Resources Information Center

Carrim, Nazir; Keet, Andre

2005-01-01

This article reflects on experiences of attempting to infuse human rights in the South African Revised National Curriculum Statement (RNCS). Using our experiences as members of Human Rights and Inclusivity Group (HRIWG), one of the curriculum development structures set up for the RNCS, and focusing particularly on the Learning Area of Mathematics,…

The Genetic Structure and History of Africans and African Americans

PubMed Central

Tishkoff, Sarah A.; Reed, Floyd A.; Friedlaender, Françoise R.; Ehret, Christopher; Ranciaro, Alessia; Froment, Alain; Hirbo, Jibril B.; Awomoyi, Agnes A.; Bodo, Jean-Marie; Doumbo, Ogobara; Ibrahim, Muntaser; Juma, Abdalla T.; Kotze, Maritha J.; Lema, Godfrey; Moore, Jason H.; Mortensen, Holly; Nyambo, Thomas B.; Omar, Sabah A.; Powell, Kweli; Pretorius, Gideon S.; Smith, Michael W.; Thera, Mahamadou A.; Wambebe, Charles; Weber, James L.; Williams, Scott M.

2010-01-01

Africa is the source of all modern humans, but characterization of genetic variation and of relationships among populations across the continent has been enigmatic. We studied 121 African populations, four African American populations, and 60 non-African populations for patterns of variation at 1327 nuclear microsatellite and insertion/deletion markers. We identified 14 ancestral population clusters in Africa that correlate with self-described ethnicity and shared cultural and/or linguistic properties. We observed high levels of mixed ancestry in most populations, reflecting historical migration events across the continent. Our data also provide evidence for shared ancestry among geographically diverse hunter-gatherer populations (Khoesan speakers and Pygmies). The ancestry of African Americans is predominantly from Niger-Kordofanian (~71%), European (~13%), and other African (~8%) populations, although admixture levels varied considerably among individuals. This study helps tease apart the complex evolutionary history of Africans and African Americans, aiding both anthropological and genetic epidemiologic studies. PMID:19407144

Research priorities for Chagas disease, human African trypanosomiasis and leishmaniasis.

PubMed

2012-01-01

This report provides a review and analysis of the research landscape for three diseases - Chagas disease, human African trypanosomiasis and leishmaniasis - that disproportionately afflict poor and remote populations with limited access to health services. It represents the work of the disease reference group on Chagas Disease, Human African Trypanosomiasis and Leishmaniasis (DRG3) which was established to identify key research priorities through review of research evidence and input from stakeholders' consultations. The diseases, which are caused by related protozoan parasites, are described in terms of their epidemiology and diseases burden, clinical forms and pathogenesis, HIV coinfection, diagnosis, drugs and drug resistance, vaccines, vector control, and health-care interventions. Priority areas for research are identified based on criteria such as public health relevance, benefit and impact on poor populations and equity, and feasibility. The priorities are found in the areas of diagnostics, drugs, vector control, asymptomatic infection, economic analysis of treatment and vector control methods, and in some specific issues such as surveillance methods or transmission-blocking vaccines for particular diseases. This report will be useful to researchers, policy and decision-makers, funding bodies, implementation organizations, and civil society. This is one of ten disease and thematic reference group reports that have come out of the TDR Think Tank, all of which have contributed to the development of the Global Report for Research on Infectious Diseases of Poverty, available at: www.who.int/tdr/stewardship/global_report/en/index.html.

Towards Human Rights in South African Schools: An Agenda for Research and Practice.

ERIC Educational Resources Information Center

Kruss, Glenda

2001-01-01

Develops a taxonomy of four kinds of situations in which race and other grounds for discrimination become the focus of school-level controversy surrounding equality and equity. Examines the kinds of responses and discourses South African schools use to engage with the policy discourse of desegregation and human rights and establishes an agenda for…

Projections of 21st Century African Climate: Implications for African Savanna Fire Dynamics, Human Health and Food Security

NASA Astrophysics Data System (ADS)

Adegoke, J. O.

2015-12-01

Fire is a key agent of change in the African savannas, which are shaped through the complex interactions between trees, C4 grasses, rainfall, temperature, CO2 and fire. These fires and their emitted smoke can have numerous direct and indirect effects on the environment, water resources, air quality, and climate. For instance, veld fires in southern Africa cause large financial losses to agriculture, livestock production and forestry on an annual basis. This study contributes to our understanding of the implications of projected surface temperature evolution in Africa for fire risk, human health and agriculture over the coming decades. We use an ensemble of high-resolution regional climate model simulations of African climate for the 21st century. Regional dowscalings and recent global circulation model projections obtained for Africa indicate that African temperatures are likely to rise at 1.5 times the global rate of temperature increase in the tropics, and at almost twice the global rate of increase in the subtropics. Warming is projected to occur during the 21st century, with increases of 4-6 °C over the subtropics and 3-5 °C over the tropics plausible by the end of the century relative to present-day climate under the A2 (low mitigation) scenario. We explore the significance of the projected warming by documenting increases in projected high fire danger days and heat-wave days. General drying is projected across the continent, even for areas (e.g. tropical Africa) where an increase in rainfall is plausible. This is due to the drastic increases in temperature that are projected, which leads to drier soils (through enhanced evaporation) despite the rainfall increases. This will likely impact negatively on crop yield, particularly on the maize crop that is of crucial importance in terms of African food security.

Inhibition of isoleucyl-tRNA synthetase as a potential treatment for human African Trypanosomiasis.

PubMed

Cestari, Igor; Stuart, Kenneth

2013-05-17

Trypanosoma brucei sp. causes human African trypanosomiasis (HAT; African sleeping sickness). The parasites initially proliferate in the hemolymphatic system and then invade the central nervous system, which is lethal if not treated. New drugs are needed for HAT because the approved drugs are few, toxic, and difficult to administer, and drug resistance is spreading. We showed by RNAi knockdown that T. brucei isoleucyl-tRNA synthetase is essential for the parasites in vitro and in vivo in a mouse model of infection. By structure prediction and experimental analysis, we also identified small molecules that inhibit recombinant isoleucyl-tRNA synthetase and that are lethal to the parasites in vitro and highly selective compared with mammalian cells. One of these molecules acts as a competitive inhibitor of the enzyme and cures mice of the infection. Because members of this class of molecules are known to cross the blood-brain barrier in humans and to be tolerated, they may be attractive as leading candidates for drug development for HAT.

African origins and chronic kidney disease susceptibility in the human immunodeficiency virus era

PubMed Central

Kasembeli, Alex N; Duarte, Raquel; Ramsay, Michèle; Naicker, Saraladevi

2015-01-01

Chronic kidney disease (CKD) is a major public health problem worldwide with the estimated incidence growing by approximately 6% annually. There are striking ethnic differences in the prevalence of CKD such that, in the United States, African Americans have the highest prevalence of CKD, four times the incidence of end stage renal disease when compared to Americans of European ancestry suggestive of genetic predisposition. Diabetes mellitus, hypertension and human immunodeficiency virus (HIV) infection are the major causes of CKD. HIV-associated nephropathy (HIVAN) is an irreversible form of CKD with considerable morbidity and mortality and is present predominantly in people of African ancestry. The APOL1 G1 and G2 alleles were more strongly associated with the risk for CKD than the previously examined MYH9 E1 risk haplotype in individuals of African ancestry. A strong association was reported in HIVAN, suggesting that 50% of African Americans with two APOL1 risk alleles, if untreated, would develop HIVAN. However these two variants are not enough to cause disease. The prevailing belief is that modifying factors or second hits (including genetic hits) underlie the pathogenesis of kidney disease. This work reviews the history of genetic susceptibility of CKD and outlines current theories regarding the role for APOL1 in CKD in the HIV era. PMID:25949944

Humans as Agents in the Termination of the African Humid Period

NASA Astrophysics Data System (ADS)

Wright, David K.

2017-01-01

There is great uncertainty over the timing and magnitude of the termination of the African Humid Period (AHP). Spanning from the early to middle Holocene, the AHP was a period of enhanced moisture over most of northern and eastern Africa. However, beginning 8000 years ago the moisture balance shifted due to changing orbital precession and vegetation feedbacks. Some proxy records indicate a rapid transition from wet to dry conditions, while others indicate a more gradual changeover. Heretofore, humans have been viewed as passive agents in the termination of the AHP, responding to changing climatic conditions by adopting animal husbandry and spreading an agricultural lifestyle across the African continent. This paper explores scenarios whereby humans could be viewed as active agents in landscape denudation. During the period when agriculture was adopted in northern Africa, the regions where it was occurring were at the precipice of ecological regime shifts. Pastoralism, in particular, is argued to enhance devegetation and regime shifts in unbalanced ecosystems. Threshold crossing events were documented in the historical records of New Zealand and western North America due to the introduction of livestock. In looking at temporally correlated archaeological and paleoenvironmental records of northern Africa, similar landscape dynamics from the historical precedents are observed: reduction in net primary productivity, homogenization of the flora, transformation of the landscape into a shrub-dominated biozone and increasing xerophylic vegetation overall. Although human agents are not seen as the only forces inducing regime change during the termination of the AHP, their potential role in inducing large-scale landscape change must be properly contextualized against other global occurrences of neolithization.

Investigation of chromosome 17q as a locus for human essential hypertension in African Caribbeans.

PubMed

Knight, J; Gardner, G T; Clark, A J; Caulfield, M J

2000-06-01

Essential hypertension is a major risk factor for cardiovascular disease in humans, and originates from both genetic and environmental factors. Data from animal and more recently human studies have indicated the presence of a gene influencing blood pressure on human chromosome 17. This study tested for linkage of markers located on chromosome 17q to essential hypertension in African Caribbean hypertensive families. No support of linkage was found between the markers studied and hypertension, however only genes of a lamda sib value of less than 1.8 could be excluded Journal of Human Hypertension (2000) 14, 385-387

New Regions of the Human Genome Linked to Skin Color Variation in Some African Populations

Cancer.gov

In the first study of its kind, an international team of genomics researchers has identified new regions of the human genome that are associated with skin color variation in some African populations, opening new avenues for research on skin diseases and cancer in all populations.

Education and the Quest for Human Completion: The African and Afro-American Perspectives Compared.

ERIC Educational Resources Information Center

Mungazi, Dickson A.

This paper examines the concept of human completion, as applied to both the African and the Afro-American experience, and how the search for completion by the individual influences the collective society. The theoretical concepts of Paulo Freire and Albert Memmi are applied to both groups. Both groups have been denied equal opportunity for…

Inhibition of Isoleucyl-tRNA Synthetase as a Potential Treatment for Human African Trypanosomiasis*

PubMed Central

Cestari, Igor; Stuart, Kenneth

2013-01-01

Trypanosoma brucei sp. causes human African trypanosomiasis (HAT; African sleeping sickness). The parasites initially proliferate in the hemolymphatic system and then invade the central nervous system, which is lethal if not treated. New drugs are needed for HAT because the approved drugs are few, toxic, and difficult to administer, and drug resistance is spreading. We showed by RNAi knockdown that T. brucei isoleucyl-tRNA synthetase is essential for the parasites in vitro and in vivo in a mouse model of infection. By structure prediction and experimental analysis, we also identified small molecules that inhibit recombinant isoleucyl-tRNA synthetase and that are lethal to the parasites in vitro and highly selective compared with mammalian cells. One of these molecules acts as a competitive inhibitor of the enzyme and cures mice of the infection. Because members of this class of molecules are known to cross the blood-brain barrier in humans and to be tolerated, they may be attractive as leading candidates for drug development for HAT. PMID:23548908

Multicenter study of human papillomavirus and the human papillomavirus vaccine: knowledge and attitudes among people of African descent.

PubMed

Blackman, Elizabeth; Thurman, Natalie; Halliday, Darron; Butler, Raleigh; Francis, Dorita; Joseph, Madeline; Thompson, Jahzreel; Akers, Aletha; Andraos-Selim, Cecile; Bondzi, Cornelius; Taioli, Emanuela; Hagan, Kourtney L; Jones, Erin A; Jones, Jade; Moss, Cierra M; Smith, Ar'Lena C; Ashing, Kimlin Tam; Ragin, Camille C

2013-01-01

To compare knowledge and attitudes of human papillomavirus (HPV) and the vaccine between different cultures of African descent. A cross-sectional survey of 555 African-Americans and Afro-Caribbeans residing in the US and the Bahamas (BHM) was conducted. General knowledge about HPV and the HPV vaccine differed between the two countries significantly. Bahamian respondents were less likely to have higher numbers of correct knowledge answers when compared to Americans (Adjusted Odds Ratio [Adj. OR] 0.47, 95% Confidence Interval [CI] 0.30-0.75). Older age, regardless of location, was also associated with answering fewer questions correctly (Adj. OR 0.61, 95% CI 0.40-0.92). Attitudes related to HPV vaccination were similar between the US and BHM, but nearly 80% of BHM respondents felt that children should not be able to receive the vaccine without parental consent compared to 57% of American respondents. Grave lack of knowledge, safety and cost concerns, and influence of parental restrictions may negatively impact vaccine uptake among African-American and Afro-Caribbean persons. Interventions to increase the vaccine uptake in the Caribbean must include medical provider and parental involvement. Effective strategies for education and increasing vaccine uptake in BHM are crucial for decreasing cervical cancer burden in the Caribbean.

Identifying Darwinian Selection Acting on Different Human APOL1 Variants among Diverse African Populations

PubMed Central

Ko, Wen-Ya; Rajan, Prianka; Gomez, Felicia; Scheinfeldt, Laura; An, Ping; Winkler, Cheryl A.; Froment, Alain; Nyambo, Thomas B.; Omar, Sabah A.; Wambebe, Charles; Ranciaro, Alessia; Hirbo, Jibril B.; Tishkoff, Sarah A.

2013-01-01

Disease susceptibility can arise as a consequence of adaptation to infectious disease. Recent findings have suggested that higher rates of chronic kidney disease (CKD) in individuals with recent African ancestry might be attributed to two risk alleles (G1 and G2) at the serum-resistance-associated (SRA)-interacting-domain-encoding region of APOL1. These two alleles appear to have arisen adaptively, possibly as a result of their protective effects against human African trypanosomiasis (HAT), or African sleeping sickness. In order to explore the distribution of potential functional variation at APOL1, we studied nucleotide variation in 187 individuals across ten geographically and genetically diverse African ethnic groups with exposure to two Trypanosoma brucei subspecies that cause HAT. We observed unusually high levels of nonsynonymous polymorphism in the regions encoding the functional domains that are required for lysing parasites. Whereas allele frequencies of G2 were similar across all populations (3%–8%), the G1 allele was only common in the Yoruba (39%). Additionally, we identified a haplotype (termed G3) that contains a nonsynonymous change at the membrane-addressing-domain-encoding region of APOL1 and is present in all populations except for the Yoruba. Analyses of long-range patterns of linkage disequilibrium indicate evidence of recent selection acting on the G3 haplotype in Fulani from Cameroon. Our results indicate that the G1 and G2 variants in APOL1 are geographically restricted and that there might be other functional variants that could play a role in HAT resistance and CKD risk in African populations. PMID:23768513

Availability and affordability of treatment for Human African Trypanosomiasis.

PubMed

Etchegorry, M G; Helenport, J P; Pecoul, B; Jannin, J; Legros, D

2001-11-01

Human African Trypanosomiasis (HAT) is a re-emerging disease whose usual treatments are becoming less efficient because of the increasing parasite resistance. Availability of HAT drugs is poor and their production in danger because of technical, ecological and economic constraints. In view of this dramatic situation, a network involving experts from NGOs, WHO and pharmaceutical producers was commissioned with updating estimates of need for each HAT drug for the coming years; negotiations with potential producers of new drugs such as eflornithine; securing sustainable manufacturing of existing drugs; clinical research into new combinations of these drugs for first and second-line treatments; centralizing drug purchases and their distribution through a unique non-profit entity; and addressing regulatory and legal issues concerning new drugs.

Performance of parasitological and molecular techniques for the diagnosis and surveillance of gambiense sleeping sickness.

PubMed

Mumba Ngoyi, Dieudonné; Ali Ekangu, Rosine; Mumvemba Kodi, Marie France; Pyana, Patient Pati; Balharbi, Fatima; Decq, Mélanie; Kande Betu, Victor; Van der Veken, Wim; Sese, Claude; Menten, Joris; Büscher, Philippe; Lejon, Veerle

2014-06-01

Recently, improvements have been made to diagnostics for gambiense sleeping sickness control but their performance remains poorly documented and may depend on specimen processing prior to examination. In a prospective study in the Democratic Republic of the Congo, we compared the diagnostic performance of several parasite detection techniques, immune trypanolysis and of m18S PCR on whole blood stored in a stabilisation buffer or dried on filter paper. Individuals with CATT whole blood (WB) titer ≥1∶4 or with clinical signs indicative for sleeping sickness were examined for presence of trypanosomes in lymph node aspirate (LNA) and/or in blood. Blood was examined with Capillary Centrifugation Technique (CTC), mini-Anion Exchange Centrifugation Technique (mAECT) and mAECT on buffy coat (BC). PCR was performed on whole blood (i) stored in guanidine hydrochloride EDTA (GE) stabilisation buffer and (ii) dried on filter paper, and repeatability and reproducibility were assessed. Immune trypanolysis (TL) was performed on plasma. A total of 237 persons were included. Among 143 parasitologically confirmed cases, 85.3% had a CATT-WB titre of ≥1/8, 39.2% were positive in LNA, 47.5% in CTC, 80.4% in mAECT-WB, 90.9% in mAECT-BC, 95.1% in TL and up to 89.5% in PCR on GE-stabilised blood. PCR on GE-stabilised blood showed highest repeatability (87.8%) and inter-laboratory reproducibility (86.9%). Of the 94 non-confirmed suspects, respectively 39.4% and 23.4% were TL or PCR positive. Suboptimal specificity of PCR and TL was also suggested by latent class analysis. The combination of LNA examination with mAECT-BC offered excellent diagnostic sensitivity. For PCR, storage of blood in stabilisation buffer is to be preferred over filter paper. TL as well as PCR are useful for remote diagnosis but are not more sensitive than mAECT-BC. For TL and PCR, the specificity, and thus usefulness for management of non-confirmed suspects remain to be determined.

Performance of Parasitological and Molecular Techniques for the Diagnosis and Surveillance of Gambiense Sleeping Sickness

PubMed Central

Mumba Ngoyi, Dieudonné; Ali Ekangu, Rosine; Mumvemba Kodi, Marie France; Pyana, Patient Pati; Balharbi, Fatima; Decq, Mélanie; Kande Betu, Victor; Van der Veken, Wim; Sese, Claude; Menten, Joris; Büscher, Philippe; Lejon, Veerle

2014-01-01

Objectives Recently, improvements have been made to diagnostics for gambiense sleeping sickness control but their performance remains poorly documented and may depend on specimen processing prior to examination. In a prospective study in the Democratic Republic of the Congo, we compared the diagnostic performance of several parasite detection techniques, immune trypanolysis and of m18S PCR on whole blood stored in a stabilisation buffer or dried on filter paper. Methods Individuals with CATT whole blood (WB) titer ≥1∶4 or with clinical signs indicative for sleeping sickness were examined for presence of trypanosomes in lymph node aspirate (LNA) and/or in blood. Blood was examined with Capillary Centrifugation Technique (CTC), mini-Anion Exchange Centrifugation Technique (mAECT) and mAECT on buffy coat (BC). PCR was performed on whole blood (i) stored in guanidine hydrochloride EDTA (GE) stabilisation buffer and (ii) dried on filter paper, and repeatability and reproducibility were assessed. Immune trypanolysis (TL) was performed on plasma. Results A total of 237 persons were included. Among 143 parasitologically confirmed cases, 85.3% had a CATT-WB titre of ≥1/8, 39.2% were positive in LNA, 47.5% in CTC, 80.4% in mAECT-WB, 90.9% in mAECT-BC, 95.1% in TL and up to 89.5% in PCR on GE-stabilised blood. PCR on GE-stabilised blood showed highest repeatability (87.8%) and inter-laboratory reproducibility (86.9%). Of the 94 non-confirmed suspects, respectively 39.4% and 23.4% were TL or PCR positive. Suboptimal specificity of PCR and TL was also suggested by latent class analysis. Conclusion The combination of LNA examination with mAECT-BC offered excellent diagnostic sensitivity. For PCR, storage of blood in stabilisation buffer is to be preferred over filter paper. TL as well as PCR are useful for remote diagnosis but are not more sensitive than mAECT-BC. For TL and PCR, the specificity, and thus usefulness for management of non-confirmed suspects remain to be

Genomic evidence for an African expansion of anatomically modern humans by a Southern route.

PubMed

Ghirotto, Silvia; Penso-Dolfin, Luca; Barbujani, Guido

2011-08-01

There is general agreement among scientists about a recent (less than 200,000 yrs ago) African origin of anatomically modern humans, whereas there is still uncertainty about whether, and to what extent, they admixed with archaic populations, which thus may have contributed to the modern populations' gene pools. Data on cranial morphology have been interpreted as suggesting that, before the main expansion from Africa through the Near East, anatomically modern humans may also have taken a Southern route from the Horn of Africa through the Arabian peninsula to India, Melanesia and Australia, about 100,000 yrs ago. This view was recently supported by archaeological findings demonstrating human presence in Eastern Arabia >90,000 yrs ago. In this study we analyzed genetic variation at 111,197 nuclear SNPs in nine populations (Kurumba, Chenchu, Kamsali, Madiga, Mala, Irula, Dalit, Chinese, Japanese), chosen because their genealogical relationships are expected to differ under the alternative models of expansion (single vs. multiple dispersals). We calculated correlations between genomic distances, and geographic distances estimated under the alternative assumptions of a single dispersal, or multiple dispersals, and found a significantly stronger association for the multiple dispersal model. If confirmed, this result would cast doubts on the possibility that some non-African populations (i.e., those whose ancestors expanded through the Southern route) may have had any contacts with Neandertals.

The Notion of Ubuntu and Communalism in African Educational Discourse

ERIC Educational Resources Information Center

Venter, Elza

2004-01-01

The notion of "ubuntu" and "communalism" is of great importance in an African educational discourse, as well as in African Philosophy of Education and in African philosophical discourse. "Ubuntu" is a philosophy that promotes the common good of society and includes humanness as an essential element of human growth. In…

Rift Valley Fever Virus Circulating among Ruminants, Mosquitoes and Humans in the Central African Republic.

PubMed

Nakouné, Emmanuel; Kamgang, Basile; Berthet, Nicolas; Manirakiza, Alexandre; Kazanji, Mirdad

2016-10-01

Rift Valley fever virus (RVFV) causes a viral zoonosis, with discontinuous epizootics and sporadic epidemics, essentially in East Africa. Infection with this virus causes severe illness and abortion in sheep, goats, and cattle as well as other domestic animals. Humans can also be exposed through close contact with infectious tissues or by bites from infected mosquitoes, primarily of the Aedes and Culex genuses. Although the cycle of RVFV infection in savannah regions is well documented, its distribution in forest areas in central Africa has been poorly investigated. To evaluate current circulation of RVFV among livestock and humans living in the Central African Republic (CAR), blood samples were collected from sheep, cattle, and goats and from people at risk, such as stock breeders and workers in slaughterhouses and livestock markets. The samples were tested for anti-RVFV immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies. We also sequenced the complete genomes of two local strains, one isolated in 1969 from mosquitoes and one isolated in 1985 from humans living in forested areas. The 1271 animals sampled comprised 727 cattle, 325 sheep, and 219 goats at three sites. The overall seroprevalence of anti-RVFV IgM antibodies was 1.9% and that of IgG antibodies was 8.6%. IgM antibodies were found only during the rainy season, but the frequency of IgG antibodies did not differ significantly by season. No evidence of recent RVFV infection was found in 335 people considered at risk; however, 16.7% had evidence of past infection. Comparison of the nucleotide sequences of the strains isolated in the CAR with those isolated in other African countries showed that they belonged to the East/Central African cluster. This study confirms current circulation of RVFV in CAR. Further studies are needed to determine the potential vectors involved and the virus reservoirs.

Tectonics, orbital forcing, global climate change, and human evolution in Africa: introduction to the African paleoclimate special volume.

PubMed

Maslin, Mark A; Christensen, Beth

2007-11-01

The late Cenozoic climate of Africa is a critical component for understanding human evolution. African climate is controlled by major tectonic changes, global climate transitions, and local variations in orbital forcing. We introduce the special African Paleoclimate Issue of the Journal of Human Evolution by providing a background for and synthesis of the latest work relating to the environmental context for human evolution. Records presented in this special issue suggest that the regional tectonics, appearance of C(4) plants in East Africa, and late Cenozoic global cooling combined to produce a long-term drying trend in East Africa. Of particular importance is the uplift associated with the East African Rift Valley formation, which altered wind flow patterns from a more zonal to more meridinal direction. Results in this volume suggest a marked difference in the climate history of southern and eastern Africa, though both are clearly influenced by the major global climate thresholds crossed in the last 3 million years. Papers in this volume present lake, speleothem, and marine paleoclimate records showing that the East African long-term drying trend is punctuated by episodes of short, alternating periods of extreme wetness and aridity. These periods of extreme climate variability are characterized by the precession-forced appearance and disappearance of large, deep lakes in the East African Rift Valley and paralleled by low and high wind-driven dust loads reaching the adjacent ocean basins. Dating of these records show that over the last 3 million years such periods only occur at the times of major global climatic transitions, such as the intensification of Northern Hemisphere Glaciation (2.7-2.5 Ma), intensification of the Walker Circulation (1.9-1.7 Ma), and the Mid-Pleistocene Revolution (1-0.7 Ma). Authors in this volume suggest this onset occurs as high latitude forcing in both Hemispheres compresses the Intertropical Convergence Zone so that East Africa

African bees to control African elephants

NASA Astrophysics Data System (ADS)

Vollrath, Fritz; Douglas-Hamilton, Iain

2002-11-01

Numbers of elephants have declined in Africa and Asia over the past 30 years while numbers of humans have increased, both substantially. Friction between these two keystone species is reaching levels which are worryingly high from an ecological as well as a political viewpoint. Ways and means must be found to keep the two apart, at least in areas sensitive to each species' survival. The aggressive African bee might be one such method. Here we demonstrate that African bees deter elephants from damaging the vegetation and trees which house their hives. We argue that bees can be employed profitably to protect not only selected trees, but also selected areas, from elephant damage.

African bees to control African elephants.

PubMed

Vollrath, Fritz; Douglas-Hamilton, Iain

2002-11-01

Numbers of elephants have declined in Africa and Asia over the past 30 years while numbers of humans have increased, both substantially. Friction between these two keystone species is reaching levels which are worryingly high from an ecological as well as a political viewpoint. Ways and means must be found to keep the two apart, at least in areas sensitive to each species' survival. The aggressive African bee might be one such method. Here we demonstrate that African bees deter elephants from damaging the vegetation and trees which house their hives. We argue that bees can be employed profitably to protect not only selected trees, but also selected areas, from elephant damage.

Early Human Speciation, Brain Expansion and Dispersal Influenced by African Climate Pulses

PubMed Central

Shultz, Susanne; Maslin, Mark

2013-01-01

Early human evolution is characterised by pulsed speciation and dispersal events that cannot be explained fully by global or continental paleoclimate records. We propose that the collated record of ephemeral East African Rift System (EARS) lakes could be a proxy for the regional paleoclimate conditions experienced by early hominins. Here we show that the presence of these lakes is associated with low levels of dust deposition in both West African and Mediterranean records, but is not associated with long-term global cooling and aridification of East Africa. Hominin expansion and diversification seem to be associated with climate pulses characterized by the precession-forced appearance and disappearance of deep EARS lakes. The most profound period for hominin evolution occurs at about 1.9 Ma; with the highest recorded diversity of hominin species, the appearance of Homo (sensu stricto) and major dispersal events out of East Africa into Eurasia. During this period, ephemeral deep-freshwater lakes appeared along the whole length of the EARS, fundamentally changing the local environment. The relationship between the local environment and hominin brain expansion is less clear. The major step-wise expansion in brain size around 1.9 Ma when Homo appeared was coeval with the occurrence of ephemeral deep lakes. Subsequent incremental increases in brain size are associated with dry periods with few if any lakes. Plio-Pleistocene East African climate pulses as evinced by the paleo-lake records seem, therefore, fundamental to hominin speciation, encephalisation and migration. PMID:24146922

Early human speciation, brain expansion and dispersal influenced by African climate pulses.

PubMed

Shultz, Susanne; Maslin, Mark

2013-01-01

Early human evolution is characterised by pulsed speciation and dispersal events that cannot be explained fully by global or continental paleoclimate records. We propose that the collated record of ephemeral East African Rift System (EARS) lakes could be a proxy for the regional paleoclimate conditions experienced by early hominins. Here we show that the presence of these lakes is associated with low levels of dust deposition in both West African and Mediterranean records, but is not associated with long-term global cooling and aridification of East Africa. Hominin expansion and diversification seem to be associated with climate pulses characterized by the precession-forced appearance and disappearance of deep EARS lakes. The most profound period for hominin evolution occurs at about 1.9 Ma; with the highest recorded diversity of hominin species, the appearance of Homo (sensu stricto) and major dispersal events out of East Africa into Eurasia. During this period, ephemeral deep-freshwater lakes appeared along the whole length of the EARS, fundamentally changing the local environment. The relationship between the local environment and hominin brain expansion is less clear. The major step-wise expansion in brain size around 1.9 Ma when Homo appeared was coeval with the occurrence of ephemeral deep lakes. Subsequent incremental increases in brain size are associated with dry periods with few if any lakes. Plio-Pleistocene East African climate pulses as evinced by the paleo-lake records seem, therefore, fundamental to hominin speciation, encephalisation and migration.

Humans and Great Apes Cohabiting the Forest Ecosystem in Central African Republic Harbour the Same Hookworms

PubMed Central

Hasegawa, Hideo; Modrý, David; Kitagawa, Masahiro; Shutt, Kathryn A.; Todd, Angelique; Kalousová, Barbora; Profousová, Ilona; Petrželková, Klára J.

2014-01-01

Background Hookworms are important pathogens of humans. To date, Necator americanus is the sole, known species of the genus Necator infecting humans. In contrast, several Necator species have been described in African great apes and other primates. It has not yet been determined whether primate-originating Necator species are also parasitic in humans. Methodology/Principal Findings The infective larvae of Necator spp. were developed using modified Harada-Mori filter-paper cultures from faeces of humans and great apes inhabiting Dzanga-Sangha Protected Areas, Central African Republic. The first and second internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA and partial cytochrome c oxidase subunit 1 (cox1) gene of mtDNA obtained from the hookworm larvae were sequenced and compared. Three sequence types (I–III) were recognized in the ITS region, and 34 cox1 haplotypes represented three phylogenetic groups (A–C). The combinations determined were I-A, II-B, II-C, III-B and III-C. Combination I-A, corresponding to N. americanus, was demonstrated in humans and western lowland gorillas; II-B and II-C were observed in humans, western lowland gorillas and chimpanzees; III-B and III-C were found only in humans. Pairwise nucleotide difference in the cox1 haplotypes between the groups was more than 8%, while the difference within each group was less than 2.1%. Conclusions/Significance The distinctness of ITS sequence variants and high number of pairwise nucleotide differences among cox1 variants indicate the possible presence of several species of Necator in both humans and great apes. We conclude that Necator hookworms are shared by humans and great apes co-habiting the same tropical forest ecosystems. PMID:24651493

Human resources for health through conflict and recovery: lessons from African countries.

PubMed

Pavignani, Enrico

2011-10-01

A protracted conflict affects human resources for health (HRH) in multiple ways. In most cases, the inflicted damage constitutes the main obstacle to health sector recovery. Interventions aimed at healing derelict human resources are however fraught with difficulties of a political, technical, financial and administrative order. The experience accumulated in past recovery processes has made some important players aware of the cost incurred by neglecting human resource development. Several transitions from conflict to peace have been documented, even if largely in unpublished reports. This paper presents condensed descriptions of some African HRH-related recovery processes, which provide useful lessons. The technical work demanded to resuscitate a derelict health workforce is fairly well understood. In most situations, the highest hurdles lie outside of the health domain, and are of a political and administrative nature. Success stories are rare. But useful lessons are taught by failure as well as by success. © 2011 The Author(s). Disasters © Overseas Development Institute, 2011.

Detection of Novel Sequences Related to African Swine Fever Virus in Human Serum and Sewage▿ †

PubMed Central

Loh, Joy; Zhao, Guoyan; Presti, Rachel M.; Holtz, Lori R.; Finkbeiner, Stacy R.; Droit, Lindsay; Villasana, Zoilmar; Todd, Collin; Pipas, James M.; Calgua, Byron; Girones, Rosina; Wang, David; Virgin, Herbert W.

2009-01-01

The family Asfarviridae contains only a single virus species, African swine fever virus (ASFV). ASFV is a viral agent with significant economic impact due to its devastating effects on populations of domesticated pigs during outbreaks but has not been reported to infect humans. We report here the discovery of novel viral sequences in human serum and sewage which are clearly related to the asfarvirus family but highly divergent from ASFV. Detection of these sequences suggests that greater genetic diversity may exist among asfarviruses than previously thought and raises the possibility that human infection by asfarviruses may occur. PMID:19812170

Differential Natural Selection of Human Zinc Transporter Genes between African and Non-African Populations

PubMed Central

Zhang, Chao; Li, Jing; Tian, Lei; Lu, Dongsheng; Yuan, Kai; Yuan, Yuan; Xu, Shuhua

2015-01-01

Zinc transporters play important roles in all eukaryotes by maintaining the rational zinc concentration in cells. However, the diversity of zinc transporter genes (ZTGs) remains poorly studied. Here, we investigated the genetic diversity of 24 human ZTGs based on the 1000 Genomes data. Some ZTGs show small population differences, such as SLC30A6 with a weighted-average FST (WA-FST = 0.015), while other ZTGs exhibit considerably large population differences, such as SLC30A9 (WA-FST = 0.284). Overall, ZTGs harbor many more highly population-differentiated variants compared with random genes. Intriguingly, we found that SLC30A9 was underlying natural selection in both East Asians (EAS) and Africans (AFR) but in different directions. Notably, a non-synonymous variant (rs1047626) in SLC30A9 is almost fixed with 96.4% A in EAS and 92% G in AFR, respectively. Consequently, there are two different functional haplotypes exhibiting dominant abundance in AFR and EAS, respectively. Furthermore, a strong correlation was observed between the haplotype frequencies of SLC30A9 and distributions of zinc contents in soils or crops. We speculate that the genetic differentiation of ZTGs could directly contribute to population heterogeneity in zinc transporting capabilities and local adaptations of human populations in regard to the local zinc state or diets, which have both evolutionary and medical implications. PMID:25927708

African rainforests: past, present and future

PubMed Central

Malhi, Yadvinder; Adu-Bredu, Stephen; Asare, Rebecca A.; Lewis, Simon L.; Mayaux, Philippe

2013-01-01

The rainforests are the great green heart of Africa, and present a unique combination of ecological, climatic and human interactions. In this synthesis paper, we review the past and present state processes of change in African rainforests, and explore the challenges and opportunities for maintaining a viable future for these biomes. We draw in particular on the insights and new analyses emerging from the Theme Issue on ‘African rainforests: past, present and future’ of Philosophical Transactions of the Royal Society B. A combination of features characterize the African rainforest biome, including a history of climate variation; forest expansion and retreat; a long history of human interaction with the biome; a relatively low plant species diversity but large tree biomass; a historically exceptionally high animal biomass that is now being severely hunted down; the dominance of selective logging; small-scale farming and bushmeat hunting as the major forms of direct human pressure; and, in Central Africa, the particular context of mineral- and oil-driven economies that have resulted in unusually low rates of deforestation and agricultural activity. We conclude by discussing how this combination of factors influences the prospects for African forests in the twenty-first century. PMID:23878339

Disparity in the Persistence of High-Risk Human Papillomavirus Genotypes Between African American and European American Women of College Age

PubMed Central

Banister, Carolyn E.; Messersmith, Amy R.; Cai, Bo; Spiryda, Lisa B.; Glover, Saundra H.; Pirisi, Lucia; Creek, Kim E.

2015-01-01

Background. Cervical cancer incidence and mortality rates are higher in African Americans than in European Americans (white, non-Hispanic of European ancestry). The reasons for this disparity are not known. Methods. We recruited a population-based longitudinal cohort of 326 European American and 113 African American female college freshmen in Columbia, South Carolina, to compare clearance of high-risk human papillomavirus (HR-HPV) infection between ethnicities. HPV testing and typing from samples obtained for Papanicolaou testing occurred every 6 months. Results. African American participants had an increased risk of testing positive for HR-HPV, compared with European American participants, but the frequency of incident HPV infection was the same in African American and European American women. Thus, exposure to HPV could not explain the higher rate of HPV positivity among African American women. The time required for 50% of participants to clear HR-HPV infection was 601 days for African American women (n = 63) and 316 days for European American women (n = 178; odds ratio [OR], 1.61; 95% confidence interval [CI], 1.08–2.53). African American women were more likely than European American women to have an abnormal result of a Papanicolaou test (OR, 1.58; 95% CI, 1.05–2.39). Conclusions. We propose that the longer time to clearance of HR-HPV among African American women leads to increased rates of abnormal results of Papanicolaou tests and contributes to the increased rates of cervical cancer observed in African American women. PMID:25028692

On the "Africanization" of English Studies in South Africa

ERIC Educational Resources Information Center

Cornwell, Gareth

2006-01-01

The article is an exploration of current trends within, and the desired destiny of, the humanities discipline of English Studies in the context of calls for the "Africanization" of South African universities. The essay advocates the embrace of a non-universalist, emancipationist humanism. (Contains 8 notes.)

Genome-Wide SNP Analysis Reveals Distinct Origins of Trypanosoma evansi and Trypanosoma equiperdum

PubMed Central

Cuypers, Bart; Van den Broeck, Frederik; Van Reet, Nick; Meehan, Conor J.; Cauchard, Julien; Wilkes, Jonathan M.; Claes, Filip; Goddeeris, Bruno; Birhanu, Hadush; Dujardin, Jean-Claude; Laukens, Kris; Büscher, Philippe

2017-01-01

Abstract Trypanosomes cause a variety of diseases in man and domestic animals in Africa, Latin America, and Asia. In the Trypanozoon subgenus, Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense cause human African trypanosomiasis, whereas Trypanosoma brucei brucei, Trypanosoma evansi, and Trypanosoma equiperdum are responsible for nagana, surra, and dourine in domestic animals, respectively. The genetic relationships between T. evansi and T. equiperdum and other Trypanozoon species remain unclear because the majority of phylogenetic analyses has been based on only a few genes. In this study, we have conducted a phylogenetic analysis based on genome-wide SNP analysis comprising 56 genomes from the Trypanozoon subgenus. Our data reveal that T. equiperdum has emerged at least once in Eastern Africa and T. evansi at two independent occasions in Western Africa. The genomes within the T. equiperdum and T. evansi monophyletic clusters show extremely little variation, probably due to the clonal spread linked to the independence from tsetse flies for their transmission. PMID:28541535

Chemotherapeutic approaches to protozoa: kinetoplastida--current level of knowledge and outlook.

PubMed

Harder, A; Greif, G; Haberkorn, A

2001-09-01

The possibilities for treating haemoflagellate infections (African trypanosomiasis) are very limited (Table 1; Mehlhorn and Schrevel 1995; Croft 1997; Hunter 1997; Wang 1997; Trouiller and Olliaro 1998). All the available drugs have severe side-effects in humans and animals. Vaccination is not really an option, in view of the wide antigen variability. At present, there are several drug combinations in clinical trials: suramin/eflornithine, suramin/metronidazole, suramin/pentamidine, melarsoprol/pentamidine, melarsoprol/nifurtimox and nifurtimox/eflornithine. Some of these combinations were successful in treating resistant Trypanosoma brucei rhodesiense and/or T. b. gambiense infections (Keiser et al. 2001). In leishmaniasis, the tendency is still to resort to the old antimony compounds, with their severe side effects. At present, miltefosine is in clinical phase and is the first oral drug against visceral leishmaniasis (Jha et al. 1999). Two drugs are currently used against Chagas' disease, although these do not cure chronic effects. There is no prospect of novel drugs in this indication either (Pecoul et al. 1999; Morel 2000).

Disparity in the persistence of high-risk human papillomavirus genotypes between African American and European American women of college age.

PubMed

Banister, Carolyn E; Messersmith, Amy R; Cai, Bo; Spiryda, Lisa B; Glover, Saundra H; Pirisi, Lucia; Creek, Kim E

2015-01-01

Cervical cancer incidence and mortality rates are higher in African Americans than in European Americans (white, non-Hispanic of European ancestry). The reasons for this disparity are not known. We recruited a population-based longitudinal cohort of 326 European American and 113 African American female college freshmen in Columbia, South Carolina, to compare clearance of high-risk human papillomavirus (HR-HPV) infection between ethnicities. HPV testing and typing from samples obtained for Papanicolaou testing occurred every 6 months. African American participants had an increased risk of testing positive for HR-HPV, compared with European American participants, but the frequency of incident HPV infection was the same in African American and European American women. Thus, exposure to HPV could not explain the higher rate of HPV positivity among African American women. The time required for 50% of participants to clear HR-HPV infection was 601 days for African American women (n = 63) and 316 days for European American women (n = 178; odds ratio [OR], 1.61; 95% confidence interval [CI], 1.08-2.53). African American women were more likely than European American women to have an abnormal result of a Papanicolaou test (OR, 1.58; 95% CI, 1.05-2.39). We propose that the longer time to clearance of HR-HPV among African American women leads to increased rates of abnormal results of Papanicolaou tests and contributes to the increased rates of cervical cancer observed in African American women. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Embracing an "African Ethos" to facilitate African immigrants participation in medical genetics and genomics research.

PubMed

Buseh, Aaron G; Stevens, Patricia E; Millon-Underwood, Sandra; Kelber, Sheryl T; Townsend, Leolia

Limited published research exists on perceptions and potentials for black African immigrants' participation in medical genetics and genomics research. This study explores the inclination and disinclination of African immigrants to be involved in genetics and genomics research. In-depth qualitative interviews were employed in which a sample of black African immigrants 18 years and older (n = 34) were interviewed. Barriers included contrary beliefs and customs about disease and the human body that differs from Western conceptions, and lack of genuine connection to the health care system. Facilitators included promotion of an "African ethos," wherein Africans unite with one another in a communal extension of self and robust community involvement across the life span of genetic studies. It is important for researchers and genetic counselors to understand the sociocultural underpinnings of African immigrants about genetics and genomics research as an initial step to encouraging their participation. Copyright © 2016 Elsevier Inc. All rights reserved.

Birth statistics for African (Loxodonta africana) and Asian (Elephas maximus) elephants in human care: history and implications for elephant welfare.

PubMed

Dale, Robert H I

2010-01-01

African (Loxodonta africana) and Asian elephants (Elephas maximus) have lived in the care of humans for many years, yet there is no consensus concerning some basic parameters describing their newborn calves. This study provides a broad empirical basis for generalizations about the birth heights, birth weights, birth times and gestation periods of elephant calves born in captivity. I obtained data concerning at least one of these four characteristics for 218 newborn calves from 74 institutions. Over the past 30 years, newborn Asian elephants have been taller and heavier than newborn African elephants. Neonatal African elephants exhibited sex differences in both weight and height, whereas neonatal Asian elephants have exhibited sex differences only in height. Primiparous dams ex situ are at least as old as their in situ counterparts, whereas ex situ sires appear to be younger than sires in range countries. Confirming earlier anecdotal evidence, both African [N=47] and Asian [N=91] dams gave birth most often at night.

A panel of Trypanosoma brucei strains tagged with blue and red-shifted luciferases for bioluminescent imaging in murine infection models.

PubMed

Van Reet, Nick; Van de Vyver, Hélène; Pyana, Patient Pati; Van der Linden, Anne Marie; Büscher, Philippe

2014-08-01

Genetic engineering with luciferase reporter genes allows monitoring Trypanosoma brucei (T.b.) infections in mice by in vivo bioluminescence imaging (BLI). Until recently, luminescent T.b. models were based on Renilla luciferase (RLuc) activity. Our study aimed at evaluating red-shifted luciferases for in vivo BLI in a set of diverse T.b. strains of all three subspecies, including some recently isolated from human patients. We transfected T.b. brucei, T.b. rhodesiense and T.b. gambiense strains with either RLuc, click beetle red (CBR) or Photinus pyralis RE9 (PpyRE9) luciferase and characterised their in vitro luciferase activity, growth profile and drug sensitivity, and their potential for in vivo BLI. Compared to RLuc, the red-shifted luciferases, CBR and PpyRE9, allow tracking of T.b. brucei AnTaR 1 trypanosomes with higher details on tissue distribution, and PpyRE9 allows detection of the parasites with a sensitivity of at least one order of magnitude higher than CBR luciferase. With CBR-tagged T.b. gambiense LiTaR1, T.b. rhodesiense RUMPHI and T.b. gambiense 348 BT in an acute, subacute and chronic infection model respectively, we observed differences in parasite tropism for murine tissues during in vivo BLI. Ex vivo BLI on the brain confirmed central nervous system infection by all luminescent strains of T.b. brucei AnTaR 1, T.b. rhodesiense RUMPHI and T.b. gambiense 348 BT. We established a genetically and phenotypically diverse collection of bioluminescent T.b. brucei, T.b. gambiense and T.b. rhodesiense strains, including drug resistant strains. For in vivo BLI monitoring of murine infections, we recommend trypanosome strains transfected with red-shifted luciferase reporter genes, such as CBR and PpyRE9. Red-shifted luciferases can be detected with a higher sensitivity in vivo and at the same time they improve the spatial resolution of the parasites in the entire body due to the better kinetics of their substrate D-luciferin.

A Panel of Trypanosoma brucei Strains Tagged with Blue and Red-Shifted Luciferases for Bioluminescent Imaging in Murine Infection Models

PubMed Central

Van Reet, Nick; Van de Vyver, Hélène; Pyana, Patient Pati; Van der Linden, Anne Marie; Büscher, Philippe

2014-01-01

Background Genetic engineering with luciferase reporter genes allows monitoring Trypanosoma brucei (T.b.) infections in mice by in vivo bioluminescence imaging (BLI). Until recently, luminescent T.b. models were based on Renilla luciferase (RLuc) activity. Our study aimed at evaluating red-shifted luciferases for in vivo BLI in a set of diverse T.b. strains of all three subspecies, including some recently isolated from human patients. Methodology/Principal findings We transfected T.b. brucei, T.b. rhodesiense and T.b. gambiense strains with either RLuc, click beetle red (CBR) or Photinus pyralis RE9 (PpyRE9) luciferase and characterised their in vitro luciferase activity, growth profile and drug sensitivity, and their potential for in vivo BLI. Compared to RLuc, the red-shifted luciferases, CBR and PpyRE9, allow tracking of T.b. brucei AnTaR 1 trypanosomes with higher details on tissue distribution, and PpyRE9 allows detection of the parasites with a sensitivity of at least one order of magnitude higher than CBR luciferase. With CBR-tagged T.b. gambiense LiTaR1, T.b. rhodesiense RUMPHI and T.b. gambiense 348 BT in an acute, subacute and chronic infection model respectively, we observed differences in parasite tropism for murine tissues during in vivo BLI. Ex vivo BLI on the brain confirmed central nervous system infection by all luminescent strains of T.b. brucei AnTaR 1, T.b. rhodesiense RUMPHI and T.b. gambiense 348 BT. Conclusions/Significance We established a genetically and phenotypically diverse collection of bioluminescent T.b. brucei, T.b. gambiense and T.b. rhodesiense strains, including drug resistant strains. For in vivo BLI monitoring of murine infections, we recommend trypanosome strains transfected with red-shifted luciferase reporter genes, such as CBR and PpyRE9. Red-shifted luciferases can be detected with a higher sensitivity in vivo and at the same time they improve the spatial resolution of the parasites in the entire body due to the better

African perceptions of female attractiveness.

PubMed

Coetzee, Vinet; Faerber, Stella J; Greeff, Jaco M; Lefevre, Carmen E; Re, Daniel E; Perrett, David I

2012-01-01

Little is known about mate choice preferences outside Western, educated, industrialised, rich and democratic societies, even though these Western populations may be particularly unrepresentative of human populations. To our knowledge, this is the first study to test which facial cues contribute to African perceptions of African female attractiveness and also the first study to test the combined role of facial adiposity, skin colour (lightness, yellowness and redness), skin homogeneity and youthfulness in the facial attractiveness preferences of any population. Results show that youthfulness, skin colour, skin homogeneity and facial adiposity significantly and independently predict attractiveness in female African faces. Younger, thinner women with a lighter, yellower skin colour and a more homogenous skin tone are considered more attractive. These findings provide a more global perspective on human mate choice and point to a universal role for these four facial cues in female facial attractiveness.

Reciprocal chromosome painting shows that the great difference in diploid number between human and African green monkey is mostly due to non-Robertsonian fissions.

PubMed

Finelli, P; Stanyon, R; Plesker, R; Ferguson-Smith, M A; O'Brien, P C; Wienberg, J

1999-07-01

We used reciprocal chromosome painting with both African green monkey (C. aethiops) and human chromosome specific DNA probes to delineate homologous regions in the two species. Probes were derived by fluorescence-activated chromosome flow sorting and then were reciprocally hybridized to metaphase spreads of each species. Segments in the size range of a single chromosome band were identified, demonstrating the sensitivity of the approach when comparing species that diverged more than 20 million years ago. Outgroup analysis shows that the great difference in diploid numbers between the African green monkey (2n = 60) and humans (2n = 46) is mainly owing to fissions, and the direction of change is towards increasing diploid numbers. However, most break points apparently lie outside of the centromere regions, suggesting that the changes were not solely Robertsonian as has been previously assumed. No reciprocal translocations have occurred in the phylogenetic lines leading to humans or African green monkeys. The primate paints established here are a valuable tool to establish interspecies homology, to define rearrangements, and to determine the mechanisms of chromosomal evolution in primate species.

[Human African trypanosomiasis: report of three cases].

PubMed

Koko, J; Ategbo, S J; Gahouma, D; Engohan-Aloghe, E; Moussavou, A

2013-08-01

Prolonged fever is an important cause of morbidity in pediatric practice, especially in tropical areas. It is above all a problem of etiological diagnosis given the vast number of etiologies. In sub-Saharan Africa, practitioners more often focus on bacterial infections and malaria at the expense of other infectious diseases such as human African trypanosomiasis (HAT), most often leading to overuse of antibiotics and antimalarials. A dramatic resurgence of HAT, also called sleeping sickness, has been reported during the last few decades in large areas of Central Africa. Furthermore, with the development of air transport, cases of children infected during a trip to Africa can be exported outside endemic areas, making diagnosis even more difficult. This parasitic infection causes a protracted, often initially unrecognized, illness with episodes of fever, headache, and malaise, accompanied by progressive lymphadenopathy, before the development of a progressive meningoencephalitis. These three case reports aim to remind practitioners of clinical and biological signs suggestive of HAT diagnosis in children living in endemic areas or having stayed there during the months prior to visiting the doctor. The prognosis is largely dependent on the precocity of diagnosis and therapeutic support. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Allocation of Academic Workloads in the Faculty of Human and Social Sciences at a South African University

ERIC Educational Resources Information Center

Botha, P. A.; Swanepoel, S.

2015-01-01

This article reports on the results of a statistical analysis of the weekly working hours of academics in a Faculty of Human and Social Sciences at a South African university. The aim was to quantify, analyse and compare the workload of academic staff. Seventy-five academics self-reported on their workload by completing the workload measuring…

Human papillomavirus status and gene expression profiles of oropharyngeal and oral cancers from European American and African American patients.

PubMed

Tomar, Swati; Graves, Christian A; Altomare, Diego; Kowli, Sangeeta; Kassler, Susannah; Sutkowski, Natalie; Gillespie, M Boyd; Creek, Kim E; Pirisi, Lucia

2016-04-01

Disparities in prevalence, human papillomavirus (HPV) status, and mortality rates for head and neck cancer have been described between African American and European American patients. We studied the HPV status and gene expression profiles in 56 oropharyngeal/oral cavity tumors and 9 normal tissue samples from European American and African American patients treated in South Carolina between 2010 and 2012. Overall, 59% of tumors were HPV DNA-positive, but only 48% of those expressed E7 mRNA (HPV-active). The prevalence of HPV-active tumors was 10% in African American patients and 39% in European American patients. Tumors positive for HPV DNA but negative for HPV mRNA exhibited gene expression profiles distinct from those of both HPV-active and HPV-negative cancers, suggesting that HPV DNA-positive/RNA-negative tumors may constitute a unique group. This study provides a direct assessment of differential expression patterns in HPV-related oropharyngeal cancer arising from African American and European American patients, for which there is a paucity of data. © 2015 Wiley Periodicals, Inc. Head Neck 00: 000-000, 2015. © 2015 Wiley Periodicals, Inc.

Present-day central African forest is a legacy of the 19th century human history.

PubMed

Morin-Rivat, Julie; Fayolle, Adeline; Favier, Charly; Bremond, Laurent; Gourlet-Fleury, Sylvie; Bayol, Nicolas; Lejeune, Philippe; Beeckman, Hans; Doucet, Jean-Louis

2017-01-17

The populations of light-demanding trees that dominate the canopy of central African forests are now aging. Here, we show that the lack of regeneration of these populations began ca. 165 ya (around 1850) after major anthropogenic disturbances ceased. Since 1885, less itinerancy and disturbance in the forest has occurred because the colonial administrations concentrated people and villages along the primary communication axes. Local populations formerly gardened the forest by creating scattered openings, which were sufficiently large for the establishment of light-demanding trees. Currently, common logging operations do not create suitable openings for the regeneration of these species, whereas deforestation degrades landscapes. Using an interdisciplinary approach, which included paleoecological, archaeological, historical, and dendrological data, we highlight the long-term history of human activities across central African forests and assess the contribution of these activities to present-day forest structure and composition. The conclusions of this sobering analysis present challenges to current silvicultural practices and to those of the future.

Evidence for an African cluster of human head and body lice with variable colors and interbreeding of lice between continents.

PubMed

Veracx, Aurélie; Boutellis, Amina; Merhej, Vicky; Diatta, Georges; Raoult, Didier

2012-01-01

Human head lice and body lice have been classified based on phenotypic characteristics, including geographical source, ecotype (preferred egg laying site hair or clothes), shape and color. More recently, genotypic studies have been based on mitochondrial genes, nuclear genes and intergenic spacers. Mitochondrial genetic analysis reclassified lice into three genotypes (A, B and C). However, no previous study has attempted to correlate both genotypic and phenotypic data. Lice were collected in four African countries: Senegal, Burundi, Rwanda and Ethiopia and were photographed to compare their colors. The Multi-Spacer-Typing (MST) method was used to genotype lice belonging to the worldwide Clade A, allowing a comparison of phenotypic and genotypic data. No congruence between louse color and genotype has been identified. Phylogenetic analysis of the spacer PM2, performed including lice from other sources, showed the existence of an African cluster of human lice. However, the analysis of other spacers suggested that lice from different areas are interbreeding. We identified two geotypes of Clade A head and body lice including one that is specifically African, that can be either black or grey and can live on the head or in clothing. We also hypothesized that lice from different areas are interbreeding.

Human Capital Development (HCD) through Open, Distance and E-Learning: Evidence from Corporate Annual Reports (CARs) of Top South African Listed Companies

ERIC Educational Resources Information Center

Adelowotan, Mo

2014-01-01

This paper discusses the role of open, distance and e-learning in the development of human resources by examining human capital development related disclosures in the corporate annual reports (CARs) of top South African listed companies. The study employed content analysis method to analyse the CARs of these companies with the aid of qualitative…

Urea Derivatives of 2-Aryl-benzothiazol-5-amines: A New Class of Potential Drugs for Human African Trypanosomiasis.

PubMed

Patrick, Donald A; Gillespie, J Robert; McQueen, Joshua; Hulverson, Matthew A; Ranade, Ranae M; Creason, Sharon A; Herbst, Zackary M; Gelb, Michael H; Buckner, Frederick S; Tidwell, Richard R

2017-02-09

A previous publication from this lab (Patrick, et al. Bioorg. Med. Chem. 2016, 24 , 2451 - 2465 ) explored the antitrypanosomal activities of novel derivatives of 2-(2-benzamido)ethyl-4-phenylthiazole (1), which had been identified as a hit against Trypanosoma brucei, the causative agent of human African trypanosomiasis. While a number of these compounds, particularly the urea analogues, were quite potent, these molecules as a whole exhibited poor metabolic stability. The present work describes the synthesis of 65 new analogues arising from medicinal chemistry optimization at different sites on the molecule. The most promising compounds were the urea derivatives of 2-aryl-benzothiazol-5-amines. One such analogue, (S)-2-(3,4-difluorophenyl)-5-(3-fluoro-N-pyrrolidylamido)benzothiazole (57) was chosen for in vivo efficacy studies based upon in vitro activity, metabolic stability, and brain penetration. This compound attained 5/5 cures in murine models of both early and late stage human African trypanosomiasis, representing a new lead for the development of drugs to combat this neglected disease.

An Overview of Trypanosoma brucei Infections: An Intense Host-Parasite Interaction.

PubMed

Ponte-Sucre, Alicia

2016-01-01

Trypanosoma brucei rhodesiense and T. brucei gambiense , the causative agents of Human African Trypanosomiasis, are transmitted by tsetse flies. Within the vector, the parasite undergoes through transformations that prepares it to infect the human host. Sequentially these developmental stages are the replicative procyclic (in which the parasite surface is covered by procyclins) and trypo-epimastigote forms, as well as the non-replicative, infective, metacyclic form that develops in the vector salivary glands. As a pre-adaptation to their life in humans, metacyclic parasites begin to express and be densely covered by the Variant Surface Glycoprotein (VSG). Once the metacyclic form invades the human host the parasite develops into the bloodstream form. Herein the VSG triggers a humoral immune response. To avoid this humoral response, and essential for survival while in the bloodstream, the parasite changes its cover periodically and sheds into the surroundings the expressed VSG, thus evading the consequences of the immune system activation. Additionally, tools comparable to quorum sensing are used by the parasite for the successful parasite transmission from human to insect. On the other hand, the human host promotes clearance of the parasite triggering innate and adaptive immune responses and stimulating cytokine and chemokine secretion. All in all, the host-parasite interaction is extremely active and leads to responses that need multiple control sites to develop appropriately.

Human resources in health research institutions in sub-Saharan African countries: results of a questionnaire-based survey.

PubMed

Kebede, Derege; Zielinski, Chris; Mbondji, Peter Ebongue; Sanou, Issa; Kouvividila, Wenceslas; Lusamba-Dikassa, Paul-Samson

2014-05-01

To describe human capacity and staff movement in national health research institutions in 42 sub-Saharan African countries. A structured questionnaire was used to solicit information on governance and stewardship from health research institutions. Eight hundred and forty-seven health research institutions in 42 sub-Saharan African countries. Key informants from 847 health research institutions. The availability, mix and quality of human resources in health research institutions. On average, there were 122 females employed per respondent health research institution, compared with 159 males. For researchers, the equivalent figures were nine females to 17 males. The average annual gross salary of researchers varied between US$ 12,260 for staff with 5-10 years of experience and US$ 14,772 for the institution head. Of those researchers who had joined the institution in the previous 12 months, 55% were employed on a full-time basis. Of the researchers who left the institutions in the same period, 71% had a full-time contract. Among all those who left, those who left to a non-research sector and to another country accounted for two-thirds. The study revealed significant gaps in the area of human capacity development for research in Africa. The results showed a serious shortage of qualified staff engaged in health research, with a dearth of staff that held at least a master's degree or doctoral degree. Major efforts will be required to strengthen human resource capacity, including addressing the lack of motivation or time for research on the part of existing capable staff. © The Royal Society of Medicine.

Secreted proteases of Trypanosoma brucei gambiense: possible targets for sleeping sickness control?

PubMed

Bossard, Géraldine; Cuny, Gérard; Geiger, Anne

2013-01-01

Human African trypanosomiasis (HAT) is caused by trypanosomes of the species Trypanosoma brucei and belongs to the neglected tropical diseases. Presently, WHO has listed 36 countries as being endemic for sleeping sickness. No vaccine is available, and disease treatment is difficult and has life-threatening side effects. Therefore, there is a crucial need to search for new therapeutic targets against the parasite. Trypanosome excreted-secreted proteins could be promising targets, as the total secretome was shown to inhibit, in vitro, host dendritic cell maturation and their ability to induce lymphocytic allogenic responses. The secretome was found surprisingly rich in various proteins and unexpectedly rich in diverse peptidases, covering more than ten peptidase families or subfamilies. Given their abundance, one may speculate that they would play a genuine role not only in classical "housekeeping" tasks but also in pathogenesis. The paper reviews the deleterious role of proteases from trypanosomes, owing to their capacity to degrade host circulating or structural proteins, as well as proteic hormones, causing severe damage and preventing host immune response. In addition, proteases account for a number of drug targets, such drugs being used to treat severe diseases such AIDS. This review underlines the importance of secreted proteins and especially of secreted proteases as potential targets in HAT-fighting strategies. It points out the need to conduct further investigations on the specific role of each of these various proteases in order to identify those playing a central role in sleeping sickness and would be suitable for drug targeting. Copyright © 2013 International Union of Biochemistry and Molecular Biology, Inc.

The peopling of the African continent and the diaspora into the new world

PubMed Central

Campbell, Michael C; Hirbo, Jibril B; Townsend, Jeffrey P; Tishkoff, Sarah A

2014-01-01

Africa is the birthplace of anatomically modern humans, and is the geographic origin of human migration across the globe within the last 100,000 years. The history of African populations has consisted of a number of demographic events that have influenced patterns of genetic and phenotypic variation across the continent. With the increasing amount of genomic data and corresponding developments in computational methods, researchers are able to explore long-standing evolutionary questions, expanding our understanding of human history within and outside of Africa. This review will summarize some of the recent findings regarding African demographic history, including the African Diaspora, and will briefly explore their implications for disease susceptibility in populations of African descent. PMID:25461616

Reducing Human-Tsetse Contact Significantly Enhances the Efficacy of Sleeping Sickness Active Screening Campaigns: A Promising Result in the Context of Elimination.

PubMed

Courtin, Fabrice; Camara, Mamadou; Rayaisse, Jean-Baptiste; Kagbadouno, Moise; Dama, Emilie; Camara, Oumou; Traoré, Ibrahima S; Rouamba, Jérémi; Peylhard, Moana; Somda, Martin B; Leno, Mamadou; Lehane, Mike J; Torr, Steve J; Solano, Philippe; Jamonneau, Vincent; Bucheton, Bruno

2015-01-01

Control of gambiense sleeping sickness, a neglected tropical disease targeted for elimination by 2020, relies mainly on mass screening of populations at risk and treatment of cases. This strategy is however challenged by the existence of undetected reservoirs of parasites that contribute to the maintenance of transmission. In this study, performed in the Boffa disease focus of Guinea, we evaluated the value of adding vector control to medical surveys and measured its impact on disease burden. The focus was divided into two parts (screen and treat in the western part; screen and treat plus vector control in the eastern part) separated by the Rio Pongo river. Population census and baseline entomological data were collected from the entire focus at the beginning of the study and insecticide impregnated targets were deployed on the eastern bank only. Medical surveys were performed in both areas in 2012 and 2013. In the vector control area, there was an 80% decrease in tsetse density, resulting in a significant decrease of human tsetse contacts, and a decrease of disease prevalence (from 0.3% to 0.1%; p=0.01), and an almost nil incidence of new infections (<0.1%). In contrast, incidence was 10 times higher in the area without vector control (>1%, p<0.0001) with a disease prevalence increasing slightly (from 0.5 to 0.7%, p=0.34). Combining medical and vector control was decisive in reducing T. b. gambiense transmission and in speeding up progress towards elimination. Similar strategies could be applied in other foci.

Human scFv antibodies (Afribumabs) against Africanized bee venom: Advances in melittin recognition.

PubMed

Pessenda, Gabriela; Silva, Luciano C; Campos, Lucas B; Pacello, Elenice M; Pucca, Manuela B; Martinez, Edson Z; Barbosa, José E

2016-03-15

Africanized Apis mellifera bees, also known as killer bees, have an exceptional defensive instinct, characterized by mass attacks that may cause envenomation or death. From the years 2000-2013, 77,066 bee accidents occurred in Brazil. Bee venom comprises several substances, including melittin and phospholipase A2 (PLA2). Due to the lack of antivenom for bee envenomation, this study aimed to produce human monoclonal antibody fragments (single chain fragment variable; scFv), by using phage display technology. These fragments targeted melittin and PLA2, the two major components of bee venom, to minimize their toxic effects in cases of mass envenomation. Two phage antibody selections were performed using purified melittin. As the commercial melittin is contaminated with PLA2, phages specific to PLA2 were also obtained during one of the selections. Specific clones for melittin and PLA2 were selected for the production of soluble scFvs, named here Afribumabs: prefix: afrib- (from Africanized bee); stem/suffix: -umab (fully human antibody). Afribumabs 1 and 2 were tested in in vitro and in vivo assays to assess their ability to inhibit the toxic actions of purified melittin, PLA2, and crude bee venom. Afribumabs reduced hemolysis caused by purified melittin and PLA2 and by crude venom in vitro and reduced edema formation in the paws of mice and prolonged the survival of venom-injected animals in vivo. These results demonstrate that Afribumabs may contribute to the production of the first non-heterologous antivenom treatment against bee envenomation. Such a treatment may overcome some of the difficulties associated with conventional immunotherapy techniques. Copyright © 2016 Elsevier Ltd. All rights reserved.

Outcome of acute East African trypanosomiasis in a Polish traveller treated with pentamidine

PubMed Central

2014-01-01

Background African trypanosomiasis is a parasitic infection sporadically imported to Europe by tourists or immigrants returning from endemic areas. We present the first and an unusual case of East African trypanosomiasis imported to Poland by a patient returning from a tourist trip to Uganda and Rwanda, which was successfully treated with pentamidine. Case presentation A 61-year-old Polish man was admitted to the Department because of high-grade fever and multi-organ dysfunction after a tourist trip to East Africa. He experienced a single tsetse fly bite during a safari trip to the Queen Elizabeth National Park in Uganda. On admission, his clinical status was severe, with high fever of 41ºC, preceded by chills, bleeding from the gums and oral mucosa, haemorrhages at the sites of venipuncture, numerous ecchymoses, fine-spotted skin rash, tachycardia, hepatosplenomegaly, dehydration, jaundice, dyspnoea, hypoxaemia, generalised oedema and oliguria. There was a typical non-painful trypanosomal chancre with central necrosis and peripheral erythema on his left arm. Laboratory investigations showed leucopenia, thrombocytopenia, haemolytic anaemia, hyperbilirubinaemia, hypoglycaemia, elevated creatinine and urea, high activity of aminotransferases, elevated levels of inflammatory markers, hypoproteinaemia, proteinuria, abnormal clotting and bleeding times, low fibrinogen level, metabolic acidosis, and electrolyte disturbances. A peripheral blood smear showed numerous Trypanosoma brucei trypomastigotes with a massive parasitaemia of 100,000/μl. T. brucei rhodesiense subspecies was finally identified on the basis of the characteristic serum resistance-associated gene using a polymerase chain reaction, and a seroconversion of specific immunoglobulin M and G antibodies in the peripheral blood by enzyme-linked immunosorbent assay. Serological tests for T. brucei gambiense subspecies were negative. A severe clinical course of acute rhodesiense trypanosomiasis with renal

African and Non-African Admixture Components in African Americans and An African Caribbean Population

PubMed Central

Murray, Tanda; Beaty, Terri H.; Mathias, Rasika A.; Rafaels, Nicholas; Grant, Audrey Virginia; Faruque, Mezbah U.; Watson, Harold R.; Ruczinski, Ingo; Dunston, Georgia M.; Barnes, Kathleen C.

2013-01-01

Admixture is a potential source of confounding in genetic association studies, so it becomes important to detect and estimate admixture in a sample of unrelated individuals. Populations of African descent in the US and the Caribbean share similar historical backgrounds but the distributions of African admixture may differ. We selected 416 ancestry informative markers (AIMs) to estimate and compare admixture proportions using STRUCTURE in 906 unrelated African Americans (AAs) and 294 Barbadians (ACs) from a study of asthma. This analysis showed AAs on average were 72.5% African, 19.6% European and 8% Asian, while ACs were 77.4% African, 15.9% European, and 6.7% Asian which were significantly different. A principal components analysis based on these AIMs yielded one primary eigenvector that explained 54.04% of the variation and captured a gradient from West African to European admixture. This principal component was highly correlated with African vs. European ancestry as estimated by STRUCTURE (r2 = 0.992, r2 = 0.912, respectively). To investigate other African contributions to African American and Barbadian admixture, we performed PCA on ~14,000 (14k) genome-wide SNPs in AAs, ACs, Yorubans, Luhya and Maasai African groups, and estimated genetic distances (FST). We found AAs and ACs were closest genetically (FST = 0.008), and both were closer to the Yorubans than the other East African populations. In our sample of individuals of African descent, ~400 well-defined AIMs were just as good for detecting substructure as ~14,000 random SNPs drawn from a genome-wide panel of markers. PMID:20717976

QSAR modeling for anti-human African trypanosomiasis activity of substituted 2-Phenylimidazopyridines

NASA Astrophysics Data System (ADS)

Masand, Vijay H.; El-Sayed, Nahed N. E.; Mahajan, Devidas T.; Mercader, Andrew G.; Alafeefy, Ahmed M.; Shibi, I. G.

2017-02-01

In the present work, sixty substituted 2-Phenylimidazopyridines previously reported with potent anti-human African trypanosomiasis (HAT) activity were selected to build genetic algorithm (GA) based QSAR models to determine the structural features that have significant correlation with the activity. Multiple QSAR models were built using easily interpretable descriptors that are directly associated with the presence or the absence of a structural scaffold, or a specific atom. All the QSAR models have been thoroughly validated according to the OECD principles. All the QSAR models are statistically very robust (R2 = 0.80-0.87) with high external predictive ability (CCCex = 0.81-0.92). The QSAR analysis reveals that the HAT activity has good correlation with the presence of five membered rings in the molecule.

The Occurrence and Diversity of Waterborne Fungi in African Aquatic Systems: Their Impact on Water Quality and Human Health.

PubMed

Magwaza, Nontokozo M; Nxumalo, Edward N; Mamba, Bhekie B; Msagati, Titus A M

2017-05-20

Currently, there is a worldwide growing interest in the occurrence and diversity of fungi and their secondary metabolites in aquatic systems, especially concerning their role in water quality and human health. However, this concern is hampered by the scant information that is available in the literature about aquatic fungi and how they affect water quality. There are only few published reports that link certain species of aquatic fungi to human health. The common aquatic fungal species that have been reported so far in African aquatic systems belong to the hyphomycetes kingdom. This paper thus aims to survey the information about the occurrence and factors that control the distribution of different species of fungi in African aquatic systems, as well as their effect on water quality and the possible metabolic pathways that lead to the formation of toxic secondary metabolites that are responsible for the deterioration of water quality. This review will also investigate the analytical and bioanalytical procedures that have been reported for the identification of different species of waterborne fungi and their secondary metabolites.

The Occurrence and Diversity of Waterborne Fungi in African Aquatic Systems: Their Impact on Water Quality and Human Health

PubMed Central

Magwaza, Nontokozo M.; Nxumalo, Edward N.; Mamba, Bhekie B.; Msagati, Titus A. M.

2017-01-01

Currently, there is a worldwide growing interest in the occurrence and diversity of fungi and their secondary metabolites in aquatic systems, especially concerning their role in water quality and human health. However, this concern is hampered by the scant information that is available in the literature about aquatic fungi and how they affect water quality. There are only few published reports that link certain species of aquatic fungi to human health. The common aquatic fungal species that have been reported so far in African aquatic systems belong to the hyphomycetes kingdom. This paper thus aims to survey the information about the occurrence and factors that control the distribution of different species of fungi in African aquatic systems, as well as their effect on water quality and the possible metabolic pathways that lead to the formation of toxic secondary metabolites that are responsible for the deterioration of water quality. This review will also investigate the analytical and bioanalytical procedures that have been reported for the identification of different species of waterborne fungi and their secondary metabolites. PMID:28531124

Present-day central African forest is a legacy of the 19th century human history

PubMed Central

Morin-Rivat, Julie; Fayolle, Adeline; Favier, Charly; Bremond, Laurent; Gourlet-Fleury, Sylvie; Bayol, Nicolas; Lejeune, Philippe; Beeckman, Hans; Doucet, Jean-Louis

2017-01-01

The populations of light-demanding trees that dominate the canopy of central African forests are now aging. Here, we show that the lack of regeneration of these populations began ca. 165 ya (around 1850) after major anthropogenic disturbances ceased. Since 1885, less itinerancy and disturbance in the forest has occurred because the colonial administrations concentrated people and villages along the primary communication axes. Local populations formerly gardened the forest by creating scattered openings, which were sufficiently large for the establishment of light-demanding trees. Currently, common logging operations do not create suitable openings for the regeneration of these species, whereas deforestation degrades landscapes. Using an interdisciplinary approach, which included paleoecological, archaeological, historical, and dendrological data, we highlight the long-term history of human activities across central African forests and assess the contribution of these activities to present-day forest structure and composition. The conclusions of this sobering analysis present challenges to current silvicultural practices and to those of the future. DOI: http://dx.doi.org/10.7554/eLife.20343.001 PMID:28093097

Limited Evidence for Classic Selective Sweeps in African Populations

PubMed Central

Granka, Julie M.; Henn, Brenna M.; Gignoux, Christopher R.; Kidd, Jeffrey M.; Bustamante, Carlos D.; Feldman, Marcus W.

2012-01-01

While hundreds of loci have been identified as reflecting strong-positive selection in human populations, connections between candidate loci and specific selective pressures often remain obscure. This study investigates broader patterns of selection in African populations, which are underrepresented despite their potential to offer key insights into human adaptation. We scan for hard selective sweeps using several haplotype and allele-frequency statistics with a data set of nearly 500,000 genome-wide single-nucleotide polymorphisms in 12 highly diverged African populations that span a range of environments and subsistence strategies. We find that positive selection does not appear to be a strong determinant of allele-frequency differentiation among these African populations. Haplotype statistics do identify putatively selected regions that are shared across African populations. However, as assessed by extensive simulations, patterns of haplotype sharing between African populations follow neutral expectations and suggest that tails of the empirical distributions contain false-positive signals. After highlighting several genomic regions where positive selection can be inferred with higher confidence, we use a novel method to identify biological functions enriched among populations’ empirical tail genomic windows, such as immune response in agricultural groups. In general, however, it seems that current methods for selection scans are poorly suited to populations that, like the African populations in this study, are affected by ascertainment bias and have low levels of linkage disequilibrium, possibly old selective sweeps, and potentially reduced phasing accuracy. Additionally, population history can confound the interpretation of selection statistics, suggesting that greater care is needed in attributing broad genetic patterns to human adaptation. PMID:22960214

Human Dispersals Along the African Rift Valley in the Late Quaternary

NASA Astrophysics Data System (ADS)

Tryon, C. A.; Faith, J. T.; Peppe, D. J.

2014-12-01

Climate- and tectonic-driven environmental dynamics of the East African Rift System (EARS) during the Quaternary played an important role in the demographic history of early Homo sapiens, including expansions of modern humans across and out of Africa. Human forager population size, geographic range, and behaviors such as hunting strategies and residential mobility likely varied in response to changes in the local and regional environment. Throughout the Quaternary, floral and faunal change was linked at least in part to variations in moisture availability, temperature, and atmospheric CO2, which in addition to uplift and faulting, contributed to the expansion and contraction of a number of large lakes that served as biogeographic barriers to many taxa. This is particularly clear for the Lake Victoria basin, where biogeographic, geological, and paleontological evidence documents repeated expansion and contraction of the ranges of species in response to lake level and vegetation change. Across much of eastern Africa, the topography of the rift facilitated north-south dispersals, the timing of which may have depended in part on the expansion and contraction of the equatorial forest belt. Dispersal potential likely increased during the more arid periods of the late Quaternary, when the roles of lakes and forests as dispersal barriers was reduced and the extent of low net primary productivity dry grasslands increased, the latter requiring large home ranges for human foragers, conditions suitable for range expansions within H. sapiens.

Practices and discourses of ubuntu: Implications for an African model of disability?

PubMed

Berghs, Maria

2017-01-01

Southern African scholars and activists working in disability studies have argued that ubuntu or unhu is a part of their world view. Thinking seriously about ubuntu, as a shared collective humanness or social ethics, means to examine how Africans have framed a struggle for this shared humanity in terms of decolonisation and activism. Three examples of applications of ubuntu are given, with two mainly linked to making explicit umaka. Firstly, ubuntu is linked to making visible the invisible inequalities for a common humanity in South Africa. Secondly, it becomes correlated to the expression of environmental justice in West and East African countries. An African model of disability that encapsulates ubuntu is correlated to how Africans have illustrated a social ethics of a common humanity in their grassroots struggles against oppression and disablement in the 20th century. Ubuntu also locates disability politically within the wider environment and practices of sustainability which are now important to the post-2105 agenda, Convention on the Rights of Persons with Disabilities (CRPD) and the (UN) Sustainable Development Goals linked to climate change. A different kind of political action linked to social justice seems to be evolving in line with ubuntu . This has implications for the future of disability studies.

Practices and discourses of ubuntu: Implications for an African model of disability?

PubMed Central

2017-01-01

Background Southern African scholars and activists working in disability studies have argued that ubuntu or unhu is a part of their world view. Objectives Thinking seriously about ubuntu, as a shared collective humanness or social ethics, means to examine how Africans have framed a struggle for this shared humanity in terms of decolonisation and activism. Method Three examples of applications of ubuntu are given, with two mainly linked to making explicit umaka. Firstly, ubuntu is linked to making visible the invisible inequalities for a common humanity in South Africa. Secondly, it becomes correlated to the expression of environmental justice in West and East African countries. Results An African model of disability that encapsulates ubuntu is correlated to how Africans have illustrated a social ethics of a common humanity in their grassroots struggles against oppression and disablement in the 20th century. Ubuntu also locates disability politically within the wider environment and practices of sustainability which are now important to the post-2105 agenda, Convention on the Rights of Persons with Disabilities (CRPD) and the (UN) Sustainable Development Goals linked to climate change. Conclusion A different kind of political action linked to social justice seems to be evolving in line with ubuntu. This has implications for the future of disability studies. PMID:28730067

Awareness of Human Papillomavirus Vaccine Among Adolescent African American Males Who Have Sex with Males: a Pilot Study.

PubMed

Onyeabor, Onyekachi S; Martin, Nicolle; Orish, Verner N; Sanyaolu, Adekunle O; Iriemenam, Nnaemeka C

2015-09-01

African American adolescent males who have sex with males (MSMs) have a high prevalence of sexually transmitted diseases (STDs) that has been directly linked to lack of access to primary care providers and reluctance to disclose their sexuality. The human papillomavirus (HPV) is the most common STD with more than 40 different serotypes and can lead to anal/genital warts as well as oral and genital cancers. The HPV vaccine if taken prior to an adolescent becoming sexually active serves a prophylactic function. The HPV vaccine is approved by the Food and Drug Administration (FDA) for girls and boys; however, HPV vaccination rates among adolescents within different minority and underserved communities have been disappointing even though these groups are disproportionately infected with the HPV virus and certain male-specific cancers. Little is known about the uptake of the vaccine among African American MSMs and thus the aim of this study. This qualitative study is based on the health belief model and assessed participants' level of awareness of HPV, the HPV vaccine, and HPV-related illnesses among 24 African American male adolescents between 16 and 18 years old who self identify as MSMs. As part of a larger study, two focus groups were conducted for African American MSMs. Participants failed to understand their potential risk for HPV given the higher rates of STD infection experienced by MSMs. They expressed very little knowledge of the HPV vaccine and are also not aware of the complications of HPV virus infection. However, they were very eager to know more about the virus and the vaccine. This study demonstrates the need for the development of health communication intervention and more research targeting African American MSMs and also the need for policy change towards making the HPV vaccine routine for males especially adolescents at no cost.

The genome landscape of indigenous African cattle.

PubMed

Kim, Jaemin; Hanotte, Olivier; Mwai, Okeyo Ally; Dessie, Tadelle; Bashir, Salim; Diallo, Boubacar; Agaba, Morris; Kim, Kwondo; Kwak, Woori; Sung, Samsun; Seo, Minseok; Jeong, Hyeonsoo; Kwon, Taehyung; Taye, Mengistie; Song, Ki-Duk; Lim, Dajeong; Cho, Seoae; Lee, Hyun-Jeong; Yoon, Duhak; Oh, Sung Jong; Kemp, Stephen; Lee, Hak-Kyo; Kim, Heebal

2017-02-20

The history of African indigenous cattle and their adaptation to environmental and human selection pressure is at the root of their remarkable diversity. Characterization of this diversity is an essential step towards understanding the genomic basis of productivity and adaptation to survival under African farming systems. We analyze patterns of African cattle genetic variation by sequencing 48 genomes from five indigenous populations and comparing them to the genomes of 53 commercial taurine breeds. We find the highest genetic diversity among African zebu and sanga cattle. Our search for genomic regions under selection reveals signatures of selection for environmental adaptive traits. In particular, we identify signatures of selection including genes and/or pathways controlling anemia and feeding behavior in the trypanotolerant N'Dama, coat color and horn development in Ankole, and heat tolerance and tick resistance across African cattle especially in zebu breeds. Our findings unravel at the genome-wide level, the unique adaptive diversity of African cattle while emphasizing the opportunities for sustainable improvement of livestock productivity on the continent.

Towards the delineation of the ancestral eutherian genome organization: comparative genome maps of human and the African elephant (Loxodonta africana) generated by chromosome painting.

PubMed Central

Frönicke, Lutz; Wienberg, Johannes; Stone, Gary; Adams, Lisa; Stanyon, Roscoe

2003-01-01

This study presents a whole-genome comparison of human and a representative of the Afrotherian clade, the African elephant, generated by reciprocal Zoo-FISH. An analysis of Afrotheria genomes is of special interest, because recent DNA sequence comparisons identify them as the oldest placental mammalian clade. Complete sets of whole-chromosome specific painting probes for the African elephant and human were constructed by degenerate oligonucleotide-primed PCR amplification of flow-sorted chromosomes. Comparative genome maps are presented based on their hybridization patterns. These maps show that the elephant has a moderately rearranged chromosome complement when compared to humans. The human paint probes identified 53 evolutionary conserved segments on the 27 autosomal elephant chromosomes and the X chromosome. Reciprocal experiments with elephant probes delineated 68 conserved segments in the human genome. The comparison with a recent aardvark and elephant Zoo-FISH study delineates new chromosomal traits which link the two Afrotherian species phylogenetically. In the absence of any morphological evidence the chromosome painting data offer the first non-DNA sequence support for an Afrotherian clade. The comparative human and elephant genome maps provide new insights into the karyotype organization of the proto-afrotherian, the ancestor of extant placental mammals, which most probably consisted of 2n=46 chromosomes. PMID:12965023

Report on the 6th African Society of Human Genetics (AfSHG) Meeting, March 12-15, 2009, Yaounde, Cameroon.

PubMed

Sirugo, Giorgio; Williams, Scott M; Royal, Charmaine D M; Newport, Melanie J; Hennig, Branwen J; Mariani-Costantini, Renato; Buonaguro, Franco M; Velez Edwards, Digna R; Ibrahim, Muntaser; Soodyall, Himla; Wonkam, Ambroise; Ramesar, Raj; Rotimi, Charles N

2010-08-01

The African Society of Human Genetics (AfSHG), founded in 2003 with its inaugural meeting in Accra, Ghana,1 has the stated missions of (1) disseminating information about human genetics research in Africa, (2) establishing a mentorship network providing educational resources, including the development of appropriate technology transfer, (3) providing advocacy for human genetic research in Africa, and (4) encouraging collaborative research. Despite its young age, the AfSHG has developed a strong cadre of active researchers, both within and outside of Africa, with more than 400 members (from 16 countries across Africa as well as 8 other countries), and has held six successful meetings, five in Africa and one in the United States.

African dust carries microbes across the ocean: are they affecting human and ecosystem health?

USGS Publications Warehouse

Kellogg, Christina A.; Griffin, Dale W.

2003-01-01

Atmospheric transport of dust from northwest Africa to the western Atlantic Ocean region may be responsible for a number of environmental hazards, including the demise of Caribbean corals; red tides; amphibian diseases; increased occurrence of asthma in humans; and oxygen depletion (eutrophication) in estuaries. Studies of satellite images suggest that hundreds of millions of tons of dust are trans-ported annually at relatively low altitudes across the Atlantic Ocean to the Caribbean Sea and southeastern United States. The dust emanates from the expanding Sahara/Sahel desert region in Africa and carries a wide variety of bacteria and fungi. The U.S. Geological Survey, in collaboration with the NASA/Goddard Spaceflight Center, is conducting a study to identify microbes--bacteria, fungi, viruses--transported across the Atlantic in African soil dust. Each year, millions of tons of desert dust blow off the west African coast and ride the trade winds across the ocean, affecting the entire Caribbean basin, as well as the southeastern United States. Of the dust reaching the U.S., Florida receives about 50 percent, while the rest may range as far north as Maine or as far west as Colorado. The dust storms can be tracked by satellite and take about one week to cross the Atlantic.

Inter-ray variation in metatarsal strength properties in humans and African apes: Implications for inferring bipedal biomechanics in the Olduvai Hominid 8 foot.

PubMed

Patel, Biren A; Jashashvili, Tea; Bui, Stephanie H; Carlson, Kristian J; Griffin, Nicole L; Wallace, Ian J; Orr, Caley M; Susman, Randall L

2018-05-12

When measured as a ratio of mean midshaft diameter to bone length, the OH 8 fossil hominin foot exhibits a metatarsal (Mt) robusticity pattern of 1 > 5 > 3 > 4 > 2, which differs from the widely perceived "common" modern human pattern (1 > 5 > 4 > 3 > 2); African apes generally exhibit a third pattern (1 > 2 > 3 > 4 > 5). Largely because of the relative ranking of Mt2 and Mt5, OH 8 metatarsals structurally resemble the pattern exhibited by bipedal humans more than the pattern of quadrupedal and climbing African apes. Considering only these three phenotypes, however, discounts the potentially important functional implications of variation in modern human (and African ape) metatarsal robusticity patterns, suggesting that they are not useful for interpreting the specific biomechanics of a bipedal gait in fossils (i.e., whether it was modern human-like or not). Using computed tomography scans to quantify metatarsal midshaft cross-sectional geometry in a large sample of Homo (n=130), Gorilla (n=44) and Pan (n=80), we documented greater variation in metatarsal robusticity patterns than previously recognized in all three groups. While apes consistently show a 1 > 2 > 3 > 4 > 5 pattern in our larger sample, there does not appear to be a similarly precise single "common" human pattern. Rather, human metatarsals converge towards a 1 > 4/5 > 2/3 pattern, where metatarsals 4 and 5, and metatarsals 2 and 3, often "flip" positions relative to each other depending on the variable examined. After reassessing what a "common" human pattern could be based on a larger sample, the previously described OH 8 pattern of 1 > 5 > 3 > 4 > 2 is only observed in some humans (<6%) and almost never in apes (<0.5%). Although this suggests an overall greater similarity to (some) humans than to any ape in loading of the foot, the relatively rare frequency of these humans in our sample underscores potential differences in loading experienced by the medial

Southern African ancient genomes estimate modern human divergence to 350,000 to 260,000 years ago.

PubMed

Schlebusch, Carina M; Malmström, Helena; Günther, Torsten; Sjödin, Per; Coutinho, Alexandra; Edlund, Hanna; Munters, Arielle R; Vicente, Mário; Steyn, Maryna; Soodyall, Himla; Lombard, Marlize; Jakobsson, Mattias

2017-11-03

Southern Africa is consistently placed as a potential region for the evolution of Homo sapiens We present genome sequences, up to 13x coverage, from seven ancient individuals from KwaZulu-Natal, South Africa. The remains of three Stone Age hunter-gatherers (about 2000 years old) were genetically similar to current-day southern San groups, and those of four Iron Age farmers (300 to 500 years old) were genetically similar to present-day Bantu-language speakers. We estimate that all modern-day Khoe-San groups have been influenced by 9 to 30% genetic admixture from East Africans/Eurasians. Using traditional and new approaches, we estimate the first modern human population divergence time to between 350,000 and 260,000 years ago. This estimate increases the deepest divergence among modern humans, coinciding with anatomical developments of archaic humans into modern humans, as represented in the local fossil record. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Arteriviruses, Pegiviruses, and Lentiviruses Are Common among Wild African Monkeys.

PubMed

Bailey, Adam L; Lauck, Michael; Ghai, Ria R; Nelson, Chase W; Heimbruch, Katelyn; Hughes, Austin L; Goldberg, Tony L; Kuhn, Jens H; Jasinska, Anna J; Freimer, Nelson B; Apetrei, Cristian; O'Connor, David H

2016-08-01

Nonhuman primates (NHPs) are a historically important source of zoonotic viruses and are a gold-standard model for research on many human pathogens. However, with the exception of simian immunodeficiency virus (SIV) (family Retroviridae), the blood-borne viruses harbored by these animals in the wild remain incompletely characterized. Here, we report the discovery and characterization of two novel simian pegiviruses (family Flaviviridae) and two novel simian arteriviruses (family Arteriviridae) in wild African green monkeys from Zambia (malbroucks [Chlorocebus cynosuros]) and South Africa (vervet monkeys [Chlorocebus pygerythrus]). We examine several aspects of infection, including viral load, genetic diversity, evolution, and geographic distribution, as well as host factors such as age, sex, and plasma cytokines. In combination with previous efforts to characterize blood-borne RNA viruses in wild primates across sub-Saharan Africa, these discoveries demonstrate that in addition to SIV, simian pegiviruses and simian arteriviruses are widespread and prevalent among many African cercopithecoid (i.e., Old World) monkeys. Primates are an important source of viruses that infect humans and serve as an important laboratory model of human virus infection. Here, we discover two new viruses in African green monkeys from Zambia and South Africa. In combination with previous virus discovery efforts, this finding suggests that these virus types are widespread among African monkeys. Our analysis suggests that one of these virus types, the simian arteriviruses, may have the potential to jump between different primate species and cause disease. In contrast, the other virus type, the pegiviruses, are thought to reduce the disease caused by human immunodeficiency virus (HIV) in humans. However, we did not observe a similar protective effect in SIV-infected African monkeys coinfected with pegiviruses, possibly because SIV causes little to no disease in these hosts. Copyright © 2016

Arteriviruses, Pegiviruses, and Lentiviruses Are Common among Wild African Monkeys

PubMed Central

Bailey, Adam L.; Lauck, Michael; Ghai, Ria R.; Nelson, Chase W.; Heimbruch, Katelyn; Hughes, Austin L.; Goldberg, Tony L.; Jasinska, Anna J.; Freimer, Nelson B.; Apetrei, Cristian

2016-01-01

ABSTRACT Nonhuman primates (NHPs) are a historically important source of zoonotic viruses and are a gold-standard model for research on many human pathogens. However, with the exception of simian immunodeficiency virus (SIV) (family Retroviridae), the blood-borne viruses harbored by these animals in the wild remain incompletely characterized. Here, we report the discovery and characterization of two novel simian pegiviruses (family Flaviviridae) and two novel simian arteriviruses (family Arteriviridae) in wild African green monkeys from Zambia (malbroucks [Chlorocebus cynosuros]) and South Africa (vervet monkeys [Chlorocebus pygerythrus]). We examine several aspects of infection, including viral load, genetic diversity, evolution, and geographic distribution, as well as host factors such as age, sex, and plasma cytokines. In combination with previous efforts to characterize blood-borne RNA viruses in wild primates across sub-Saharan Africa, these discoveries demonstrate that in addition to SIV, simian pegiviruses and simian arteriviruses are widespread and prevalent among many African cercopithecoid (i.e., Old World) monkeys. IMPORTANCE Primates are an important source of viruses that infect humans and serve as an important laboratory model of human virus infection. Here, we discover two new viruses in African green monkeys from Zambia and South Africa. In combination with previous virus discovery efforts, this finding suggests that these virus types are widespread among African monkeys. Our analysis suggests that one of these virus types, the simian arteriviruses, may have the potential to jump between different primate species and cause disease. In contrast, the other virus type, the pegiviruses, are thought to reduce the disease caused by human immunodeficiency virus (HIV) in humans. However, we did not observe a similar protective effect in SIV-infected African monkeys coinfected with pegiviruses, possibly because SIV causes little to no disease in these hosts

Beyond lip service: Towards human rights-driven guidelines for South African speech-language pathologists.

PubMed

Pascoe, Michelle; Klop, Daleen; Mdlalo, Thandeka; Ndhambi, Mikateko

2018-02-01

Developed with a strong awareness of past injustices, South Africa's progressive constitution emphasises a full spectrum of human rights. While the constitution celebrates many languages and cultures, speech-language pathologists (SLPs) face challenges in translating these values into practice with a diverse clientele. Similarly, Article 19 of the Universal Declaration of Human Rights focuses on freedom of expression in one's language of choice, but is often perceived as a "Cinderella" right (i.e. one that is frequently neglected). This paper presents a literature review undertaken in association with the Health Professions Council of South Africa to produce guidelines to support SLPs in their practice with diverse linguistic and cultural groups. The aim was to identify key points for inclusion in a set of human rights-driven guidelines. Specific objectives were to critique: (1) current guidelines for SLPs working with diverse cultural and linguistic groups; and (2) equivalent guidelines for related professions. Content analysis of the datasets revealed key themes which formed the basis of an initial skeleton, to be further developed through a consultative process and discussion, ultimately aiming to provide supportive, practical guidelines to better equip South African SLPs to serve all the people of the country.

Status of pharmaceuticals in African water bodies: Occurrence, removal and analytical methods.

PubMed

Madikizela, Lawrence Mzukisi; Tavengwa, Nikita Tawanda; Chimuka, Luke

2017-05-15

In this review paper, the milestones and challenges that have been achieved and experienced by African Environmental Scientists regarding the assessment of water pollution caused by the presence of pharmaceutical compounds in water bodies are highlighted. The identification and quantification of pharmaceuticals in the African water bodies is important to the general public at large due to the lack of information. The consumption of pharmaceuticals to promote human health is usually followed by excretion of these drugs via urine or fecal matter due to their slight transformation in the human metabolism. Therefore, large amounts of pharmaceuticals are being discharged continuously from wastewater treatment plants into African rivers due to inefficiency of employed sewage treatment processes. Large portions of African communities do not even have proper sanitation systems which results in direct contamination of water resources with human waste that contains pharmaceutical constituents among other pollutants. Therefore, this article provides the overview of the recent studies published, mostly from 2012 to 2016, that have focused on the occurrence of different classes of pharmaceuticals in African aqueous systems. Also, the current analytical methods that are being used in Africa for pharmaceutical quantification in environmental waters are highlighted. African Scientists have started to investigate the materials and remediation processes for the elimination of pharmaceuticals from water. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of Human FcγRIIA (CD32) and FcγRIIIB (CD16) Polymorphisms in Caucasians and African-Americans Using Salivary DNA

PubMed Central

van Schie, Rob C. A. A.; Wilson, Mark E.

2000-01-01

Two classes of low-affinity receptors for the Fc region of immunoglobulin G (IgG) (FcγR) are constitutively expressed on resting human neutrophils. These receptors, termed FcγRIIa (CD32) and FcγRIIIb (CD16), display biallelic polymorphisms which have functional consequences with respect to binding and/or ingestion of targets opsonized by human IgG subclass antibodies. The H131-R131 polymorphism of CD32 influences binding of human IgG2 and, to a lesser extent, human IgG3 to neutrophils. The neutrophil antigen (NA1-NA2) polymorphism of CD16 influences the efficiency of phagocytosis of bacteria opsonized by human IgG1 and IgG3. These polymorphisms may influence host susceptibility to certain infectious and/or autoimmune diseases, prompting interest in the development of facile methods for determination of CD32 and CD16 genotype in various clinical settings. We previously reported that genomic DNA from saliva is a suitable alternative to DNA from blood in PCR-based analyses of CD32 and CD16 polymorphisms. In the present study, we utilized for the first time this salivary DNA-based methodology to define CD32 and CD16 genotypes in 271 Caucasian and 118 African-American subjects and to investigate possible linkage disequilibrium between certain CD32 and CD16 genotypes in these two ethnic groups. H131 and R131 gene frequencies were 0.45 and 0.55, respectively, among Caucasians and 0.59 among African-Americans. NA1 and NA2 gene frequencies were 0.38 and 0.62 among Caucasians and 0.39 and 0.61 among African-Americans. Since FcγRIIa and FcγRIIIb synergize in triggering neutrophils, we also assessed the frequency of different CD32 and CD16 genotype combinations in these two groups. In both groups, the R/R131-NA2/NA2 genotype combination was more common than the H/H131-NA1/NA1 combination (threefold for Caucasians versus sevenfold for African-Americans). Whether individuals with the combined R/R131-NA2/NA2 genotype are at greater risk for development of infectious and

Association of substance use disorders with childhood trauma but not African genetic heritage in an African American cohort.

PubMed

Ducci, Francesca; Roy, Alec; Shen, Pei-Hong; Yuan, Qiaoping; Yuan, Nicole P; Hodgkinson, Colin A; Goldman, Lynn R; Goldman, David

2009-09-01

Genetic variation influences differential vulnerability to addiction within populations. However, it remains unclear whether differences in frequencies of vulnerability alleles contribute to disparities between populations and to what extent ancestry correlates with differential exposure to environmental risk factors, including poverty and trauma. The authors used 186 ancestry-informative markers to measure African ancestry in 407 addicts and 457 comparison subjects self-identified as African Americans. The reference group was 1,051 individuals from the Human Genome Diversity Cell Line Panel, which includes 51 diverse populations representing most worldwide genetic diversity. African Americans varied in degrees of African, European, Middle Eastern, and Central Asian genetic heritage. The overall level of African ancestry was actually smaller among cocaine, opiate, and alcohol addicts (proportion=0.76-0.78) than nonaddicted African American comparison subjects (proportion=0.81). African ancestry was associated with living in impoverished neighborhoods, a factor previously associated with risk. There was no association between African ancestry and exposure to childhood abuse or neglect, a factor that strongly predicted all types of addictions. These results suggest that African genetic heritage does not increase the likelihood of genetic risk for addictions. They highlight the complex interrelation between genetic ancestry and social, economic, and environmental conditions and the strong relation of those factors to addiction. Studies of epidemiological samples characterized for genetic ancestry and social, psychological, demographic, economic, cultural, and historical factors are needed to better disentangle the effects of genetic and environmental factors underlying interpopulation differences in vulnerability to addiction and other health disparities.

Association of Substance Use Disorders With Childhood Trauma but not African Genetic Heritage in an African American Cohort

PubMed Central

Ducci, Francesca; Roy, Alec; Shen, Pei-Hong; Yuan, Qiaoping; Yuan, Nicole P.; Hodgkinson, Colin A.; Goldman, Lynn R.; Goldman, David

2009-01-01

Objective Genetic variation influences differential vulnerability to addiction within populations. However, it remains unclear whether differences in frequencies of vulnerability alleles contribute to disparities between populations and to what extent ancestry correlates with differential exposure to environmental risk factors, including poverty and trauma. Method The authors used 186 ancestry-informative markers to measure African ancestry in 407 addicts and 457 comparison subjects self-identified as African Americans. The reference group was 1,051 individuals from the Human Genome Diversity Cell Line Panel, which includes 51 diverse populations representing most worldwide genetic diversity. Results African Americans varied in degrees of African, European, Middle Eastern, and Central Asian genetic heritage. The overall level of African ancestry was actually smaller among cocaine, opiate, and alcohol addicts (proportion=0.76–0.78) than nonaddicted African American comparison subjects (proportion=0.81). African ancestry was associated with living in impoverished neighborhoods, a factor previously associated with risk. There was no association between African ancestry and exposure to childhood abuse or neglect, a factor that strongly predicted all types of addictions. Conclusions These results suggest that African genetic heritage does not increase the likelihood of genetic risk for addictions. They highlight the complex interrelation between genetic ancestry and social, economic, and environmental conditions and the strong relation of those factors to addiction. Studies of epidemiological samples characterized for genetic ancestry and social, psychological, demographic, economic, cultural, and historical factors are needed to better disentangle the effects of genetic and environmental factors underlying interpopulation differences in vulnerability to addiction and other health disparities. PMID:19605534

Black versus Black: The Relationship among African, African American, and African Caribbean Persons.

ERIC Educational Resources Information Center

Jackson, Jennifer V.; Cothran, Mary E.

2003-01-01

Surveyed people of African descent regarding relationships among African, African-American, and African-Caribbean persons, focusing on contact and friendship, travel to countries of the diaspora, cross-cultural communication, thoughts and stereotypes, and education. Most respondents had contacts with the other groups, but groups had preconceived…

Detailed Analysis of the African Green Monkey Model of Nipah Virus Disease

PubMed Central

Johnston, Sara C.; Briese, Thomas; Bell, Todd M.; Pratt, William D.; Shamblin, Joshua D.; Esham, Heather L.; Donnelly, Ginger C.; Johnson, Joshua C.; Hensley, Lisa E.; Lipkin, W. Ian; Honko, Anna N.

2015-01-01

Henipaviruses are implicated in severe and frequently fatal pneumonia and encephalitis in humans. There are no approved vaccines or treatments available for human use, and testing of candidates requires the use of well-characterized animal models that mimic human disease. We performed a comprehensive and statistically-powered evaluation of the African green monkey model to define parameters critical to disease progression and the extent to which they correlate with human disease. African green monkeys were inoculated by the intratracheal route with 2.5×104 plaque forming units of the Malaysia strain of Nipah virus. Physiological data captured using telemetry implants and assessed in conjunction with clinical pathology were consistent with shock, and histopathology confirmed widespread tissue involvement associated with systemic vasculitis in animals that succumbed to acute disease. In addition, relapse encephalitis was identified in 100% of animals that survived beyond the acute disease phase. Our data suggest that disease progression in the African green monkey is comparable to the variable outcome of Nipah virus infection in humans. PMID:25706617

Social Motility in African Trypanosomes

PubMed Central

McLelland, Bryce T.; Hill, Kent L.

2010-01-01

African trypanosomes are devastating human and animal pathogens that cause significant human mortality and limit economic development in sub-Saharan Africa. Studies of trypanosome biology generally consider these protozoan parasites as individual cells in suspension cultures or in animal models of infection. Here we report that the procyclic form of the African trypanosome Trypanosoma brucei engages in social behavior when cultivated on semisolid agarose surfaces. This behavior is characterized by trypanosomes assembling into multicellular communities that engage in polarized migrations across the agarose surface and cooperate to divert their movements in response to external signals. These cooperative movements are flagellum-mediated, since they do not occur in trypanin knockdown parasites that lack normal flagellum motility. We term this behavior social motility based on features shared with social motility and other types of surface-induced social behavior in bacteria. Social motility represents a novel and unexpected aspect of trypanosome biology and offers new paradigms for considering host-parasite interactions. PMID:20126443

Human Alu insertion polymorphisms in North African populations.

PubMed

Cherni, Loth; Frigi, Sabeh; Ennafaa, Hajer; Mtiraoui, Nabil; Mahjoub, Touhami; Benammar-Elgaaied, Amel

2011-10-01

Several features make Alu insertions a powerful tool used in population genetic studies: the polymorphic nature of many Alu insertions, the stability of an Alu insertion event and, furthermore, the ancestral state of an Alu insertion is known to be the absence of the Alu element at a particular locus and the presence of an Alu insertion at the site that forward mutational change. This study analyses seven Alu insertion polymorphisms in a sample of 297 individuals from the autochthonous population of Tunisia (Thala, Smar, Zarzis, and Bou Salem) and Libya with the aim of studying their genetic structure with respect to the populations of North Africa, Western, Eastern and Central Europe. The comparative analyses carried out using the MDS and AMOVA methods reveal the existence of spatial heterogeneity, and identify four population groups. Study populations (Libya, Smar, Zarzis, and Bou Salem) are closest to North African populations whereas Thala is isolated and is closest to Western European populations. In conclusion, Results of the present study support the important role that migratory movements have played in the North African gene pool, at least since the Neolithic period.

African-American wildland memories

Treesearch

Cassandra Y. Johnson; J. Michael Bowker

2004-01-01

Collective memory can be used conceptually to examine African-American perceptions of wildlands and black interaction with such places. The middle--American view of wildlands frames these terrains as refuges--pure and simple, sanctified places distinct from the profanity of human modification. However, wild, primitive areas do not exist in the minds of all Americans as...

An African ethic for nursing?

PubMed

Haegert, S

2000-11-01

This article derives from a doctoral thesis in which a particular discourse was used as a 'paradigm case'. From this discourse an ethic set within a South African culture arose. Using many cultural 'voices' to aid the understanding of this narrative, the ethic shows that one can build on both a 'justice' and a 'care' ethic. With further development based on African culture one can take the ethic of care deeper and reveal 'layers of understanding'. Care, together with compassion, forms the foundation of morality. Nursing ethics has followed particular western moral philosophers. Often nursing ethics has been taught along the lines of Kohlberg's theory of morality, with its emphasis on rules, rights, duties and general obligations. These principles were universalistic, masculine and noncontextual. However, there is a new ethical movement among Thomist philosophers along the lines to be expounded in this article. Nurses such as Benner, Bevis, Dunlop, Fry and Gadow--to name but a few--have welcomed the concept of an 'ethic of care'. Gilligan's work gave a feminist view and situated ethics in the everyday aspects of responsiveness, responsibility, context and concern. Shutte's search for a 'philosophy for Africa' has resulted in finding similarities in Setiloane and in Senghor with those of Thomist philosophers. Using this African philosophy and a research participant's narrative, an African ethic evolves out of the African proverb: 'A person is a person through other persons', or its alternative rendering: 'I am because we are: we are because I am.' This hermeneutic narrative reveals 'the way affect imbues activity with ethical meaning' within the context of a black nursing sister in a rural South African hospital. It expands upon the above proverb and incorporates the South African constitutional idea of 'Ubuntu' (compassion and justice or humanness).

Different Cranial Ontogeny in Europeans and Southern Africans

PubMed Central

Sardi, Marina L.; Ramírez Rozzi, Fernando V.

2012-01-01

Modern human populations differ in developmental processes and in several phenotypic traits. However, the link between ontogenetic variation and human diversification has not been frequently addressed. Here, we analysed craniofacial ontogenies by means of geometric-morphometrics of Europeans and Southern Africans, according to dental and chronological ages. Results suggest that different adult cranial morphologies between Southern Africans and Europeans arise by a combination of processes that involve traits modified during the prenatal life and others that diverge during early postnatal ontogeny. Main craniofacial changes indicate that Europeans differ from Southern Africans by increasing facial developmental rates and extending the attainment of adult size and shape. Since other studies have suggested that native subsaharan populations attain adulthood earlier than Europeans, it is probable that facial ontogeny is linked with other developmental mechanisms that control the timing of maturation in other variables. Southern Africans appear as retaining young features in adulthood. Facial ontogeny in Europeans produces taller and narrower noses, which seems as an adaptation to colder environments. The lack of these morphological traits in Neanderthals, who lived in cold environments, seems a paradox, but it is probably the consequence of a warm-adapted faces together with precocious maturation. When modern Homo sapiens migrated into Asia and Europe, colder environments might establish pressures that constrained facial growth and development in order to depart from the warm-adapted morphology. Our results provide some answers about how cranial growth and development occur in two human populations and when developmental shifts take place providing a better adaptation to environmental constraints. PMID:22558270

Negro, Black, Black African, African Caribbean, African American or what? Labelling African origin populations in the health arena in the 21st century

PubMed Central

Agyemang, C.; Bhopal, R.; Bruijnzeels, M.

2005-01-01

Broad terms such as Black, African, or Black African are entrenched in scientific writings although there is considerable diversity within African descent populations and such terms may be both offensive and inaccurate. This paper outlines the heterogeneity within African populations, and discusses the strengths and limitations of the term Black and related labels from epidemiological and public health perspectives in Europe and the USA. This paper calls for debate on appropriate terminologies for African descent populations and concludes with the proposals that (1) describing the population under consideration is of paramount importance (2) the word African origin or simply African is an appropriate and necessary prefix for an ethnic label, for example, African Caribbean or African Kenyan or African Surinamese (3) documents should define the ethnic labels (4) the label Black should be phased out except when used in political contexts. PMID:16286485

Africans in the American Labor Market.

PubMed

Elo, Irma T; Frankenberg, Elizabeth; Gansey, Romeo; Thomas, Duncan

2015-10-01

The number of migrants to the United States from Africa has grown exponentially since the 1930s. For the first time in America's history, migrants born in Africa are growing at a faster rate than migrants from any other continent. The composition of African-origin migrants has also changed dramatically: in the mid-twentieth century, the majority were white and came from only three countries; but today, about one-fifth are white, and African-origin migrants hail from across the entire continent. Little is known about the implications of these changes for their labor market outcomes in the United States. Using the 2000-2011 waves of the American Community Survey, we present a picture of enormous heterogeneity in labor market participation, sectoral choice, and hourly earnings of male and female migrants by country of birth, race, age at arrival in the United States, and human capital. For example, controlling a rich set of human capital and demographic characteristics, some migrants-such as those from South Africa/Zimbabwe and Cape Verde, who typically enter on employment visas-earn substantial premiums relative to other African-origin migrants. These premiums are especially large among males who arrived after age 18. In contrast, other migrants-such as those from Sudan/Somalia, who arrived more recently, mostly as refugees-earn substantially less than migrants from other African countries. Understanding the mechanisms generating the heterogeneity in these outcomes-including levels of socioeconomic development, language, culture, and quality of education in countries of origin, as well as selectivity of those who migrate-figures prominently among important unresolved research questions.

Independent evolution of knuckle-walking in African apes shows that humans did not evolve from a knuckle-walking ancestor.

PubMed

Kivell, Tracy L; Schmitt, Daniel

2009-08-25

Despite decades of debate, it remains unclear whether human bipedalism evolved from a terrestrial knuckle-walking ancestor or from a more generalized, arboreal ape ancestor. Proponents of the knuckle-walking hypothesis focused on the wrist and hand to find morphological evidence of this behavior in the human fossil record. These studies, however, have not examined variation or development of purported knuckle-walking features in apes or other primates, data that are critical to resolution of this long-standing debate. Here we present novel data on the frequency and development of putative knuckle-walking features of the wrist in apes and monkeys. We use these data to test the hypothesis that all knuckle-walking apes share similar anatomical features and that these features can be used to reliably infer locomotor behavior in our extinct ancestors. Contrary to previous expectations, features long-assumed to indicate knuckle-walking behavior are not found in all African apes, show different developmental patterns across species, and are found in nonknuckle-walking primates as well. However, variation among African ape wrist morphology can be clearly explained if we accept the likely independent evolution of 2 fundamentally different biomechanical modes of knuckle-walking: an extended wrist posture in an arboreal environment (Pan) versus a neutral, columnar hand posture in a terrestrial environment (Gorilla). The presence of purported knuckle-walking features in the hominin wrist can thus be viewed as evidence of arboreality, not terrestriality, and provide evidence that human bipedalism evolved from a more arboreal ancestor occupying the ecological niche common to all living apes.

Community leaders' perspectives on engaging African Americans in biobanks and other human genetics initiatives.

PubMed

Buseh, Aaron G; Stevens, Patricia E; Millon-Underwood, Sandra; Townsend, Leolia; Kelber, Sheryl T

2013-10-01

There is limited information about what African Americans think about biobanks and the ethical questions surrounding them. Likewise, there is a gap in capacity to successfully enroll African Americans as biobank donors. The purposes of this community-based participatory study were to: (a) explore African Americans' perspectives on genetics/genomic research, (b) understand facilitators and barriers to participation in such studies, and (c) enlist their ideas about how to attract and sustain engagement of African Americans in genetics initiatives. As the first phase in a mixed methods study, we conducted four focus groups with 21 African American community leaders in one US Midwest city. The sample consisted of executive directors of community organizations and prominent community activists. Data were analyzed thematically. Skepticism about biomedical research and lack of trust characterized discussions about biomedical research and biobanks. The Tuskegee Untreated Syphilis Study and the Henrietta Lacks case influenced their desire to protect their community from harm and exploitation. Connections between genetics and family history made genetics/genomics research personal, pitting intrusion into private affairs against solutions. Participants also expressed concerns about ethical issues involved in genomics research, calling attention to how research had previously been conducted in their community. Participants hoped personalized medicine might bring health benefits to their people and proposed African American communities have a "seat at the table." They called for basic respect, authentic collaboration, bidirectional education, transparency and prerogative, and meaningful benefits and remuneration. Key to building trust and overcoming African Americans' trepidation and resistance to participation in biobanks are early and persistent engagement with the community, partnerships with community stakeholders to map research priorities, ethical conduct of research, and

The Origins of African Plasmodium vivax; Insights from Mitochondrial Genome Sequencing

PubMed Central

Culleton, Richard; Coban, Cevayir; Zeyrek, Fadile Yildiz; Cravo, Pedro; Kaneko, Akira; Randrianarivelojosia, Milijaona; Andrianaranjaka, Voahangy; Kano, Shigeyuki; Farnert, Anna; Arez, Ana Paula; Sharp, Paul M.; Carter, Richard; Tanabe, Kazuyuki

2011-01-01

Plasmodium vivax, the second most prevalent of the human malaria parasites, is estimated to affect 75 million people annually. It is very rare, however, in west and central Africa, due to the high prevalence of the Duffy negative phenotype in the human population. Due to its rarity in Africa, previous studies on the phylogeny of world-wide P. vivax have suffered from insufficient samples of African parasites. Here we compare the mitochondrial sequence diversity of parasites from Africa with those from other areas of the world, in order to investigate the origin of present-day African P. vivax. Mitochondrial genome sequencing revealed relatively little polymorphism within the African population compared to parasites from the rest of the world. This, combined with sequence similarity with parasites from India, suggests that the present day African P. vivax population in humans may have been introduced relatively recently from the Indian subcontinent. Haplotype network analysis also raises the possibility that parasites currently found in Africa and South America may be the closest extant relatives of the ancestors of the current world population. Lines of evidence are adduced that this ancestral population may be from an ancient stock of P. vivax in Africa. PMID:22195007

Endothelial Cell Bioenergetics and Mitochondrial DNA Damage Differ in Humans Having African or West Eurasian Maternal Ancestry

PubMed Central

Krzywanski, David M.; Moellering, Douglas R.; Westbrook, David G.; Dunham-Snary, Kimberly J.; Brown, Jamelle; Bray, Alexander W.; Feeley, Kyle P.; Sammy, Melissa J.; Smith, Matthew R.; Schurr, Theodore G.; Vita, Joseph A.; Ambalavanan, Namasivayam; Calhoun, David; Dell’Italia, Louis; Ballinger, Scott W.

2016-01-01

Background We hypothesized that endothelial cells having distinct mitochondrial genetic backgrounds would show variation in mitochondrial function and oxidative stress markers concordant with known differential cardiovascular disease susceptibilities. To test this hypothesis, mitochondrial bioenergetics were determined in endothelial cells from healthy individuals with African versus European maternal ancestries. Methods and Results Bioenergetics and mitochondrial DNA (mtDNA) damage were assessed in single donor human umbilical vein endothelial cells (HUVECs) belonging to mtDNA haplogroups H and L, representing West Eurasian and African maternal ancestry, respectively. HUVECs from haplogroup L utilized less oxygen for ATP production and had increased levels of mtDNA damage compared to those in haplogroup H. Differences in bioenergetic capacity were also observed in that HUVECs belonging to haplogroup L had decreased maximal bioenergetic capacities compared to haplogroup H. Analysis of peripheral blood mononuclear cells from age-matched healthy controls with West Eurasian or African maternal ancestries showed that haplogroups sharing an A to G mtDNA mutation at nucleotide pair (np) 10,398 had increased mtDNA damage compared to those lacking this mutation. Further study of angiographically proven coronary artery disease patients and age-matched healthy controls revealed that mtDNA damage was associated with vascular function and remodeling, and that age of disease onset was later in individuals from haplogroups lacking the A to G mutation at np 10,398. Conclusions Differences in mitochondrial bioenergetics and mtDNA damage associated with maternal ancestry may contribute to endothelial dysfunction and vascular disease. PMID:26787433

Effectiveness of monovalent human rotavirus vaccine against admission to hospital for acute rotavirus diarrhoea in South African children: a case-control study.

PubMed

Groome, Michelle J; Page, Nicola; Cortese, Margaret M; Moyes, Jocelyn; Zar, Heather J; Kapongo, Constant N; Mulligan, Christine; Diedericks, Ralph; Cohen, Cheryl; Fleming, Jessica A; Seheri, Mapaseka; Mphahlele, Jeffrey; Walaza, Sibongile; Kahn, Kathleen; Chhagan, Meera; Steele, A Duncan; Parashar, Umesh D; Zell, Elizabeth R; Madhi, Shabir A

2014-11-01

The effectiveness of the rotavirus vaccine under conditions of routine use in an African setting with a high prevalence of HIV infection needs to be established. We assessed the vaccine effectiveness of monovalent human rotavirus vaccine in preventing admission to hospital for acute rotavirus diarrhoea, after its introduction at age 6 and 14 weeks into South Africa's national immunisation programme. This case-control study was done at seven hospitals in South Africa between April 19, 2010, and Oct 31, 2012. The hospitals were located in a range of urban, peri-urban, and rural settings, with varying rates of population HIV infection. Cases were children aged from 18 weeks to 23 months who were age-eligible to have received at least one dose of the human rotavirus vaccine (ie, those born after June 14, 2009) admitted to hospital with laboratory-confirmed acute rotavirus diarrhoea, and the primary control group was children admitted to hospital with diarrhoea testing negative for rotavirus. A second control group comprised children admitted to a subset of three of the seven hospitals with respiratory illness. The primary endpoint was adjusted vaccine effectiveness (1 - adjusted odds ratio × 100%) in children aged from 18 weeks to 23 months and was calculated by unconditional logistic regression. This study is registered on the South African National Clinical Trial Register, number DOH-27-0512-3247. Of 540 rotavirus-positive cases, 278 children (52%) received two doses, 126 (23%) one dose, and 136 (25%) no doses of human rotavirus vaccine, compared with 1434 rotavirus-negative controls of whom 856 (60%) received two doses, 334 (23%) one dose, and 244 (17%) no doses. Adjusted vaccine effectiveness using rotavirus-negative controls was 57% (95% CI 40-68) for two doses and 40% (16-57) for one dose; estimates were similar when respiratory controls were used as the control group. Adjusted vaccine effectiveness for two doses was similar between age groups 18 weeks

Antiparasitic activity of diallyl trisulfide (Dasuansu) on human and animal pathogenic protozoa (Trypanosoma sp., Entamoeba histolytica and Giardia lamblia) in vitro.

PubMed

Lun, Z R; Burri, C; Menzinger, M; Kaminsky, R

1994-03-01

Garlic (Allium sativum L.) and one of its major components, allicin, have been known to have antibacterial and antifungal activity for a long time. Diallyl trisulfide is a chemically stable final transformation product of allicin which was synthesized in 1981 in China and used for treatment of bacterial, fungal and parasitic infections in man. The activity of diallyl trisulfide was investigated in several important protozoan parasites in vitro. The IC50 (concentration which inhibits metabolism or growth of parasites by 50%) for Trypanosoma brucei brucei, T.b. rhodesiense, T.b. gambiense, T. evansi, T. congolense and T. equiperdum was in the range of 0.8-5.5 micrograms/ml. IC50 values were 59 micrograms/ml for Entamoeba histolytica and 14 micrograms/ml for Giardia lamblia. The cytotoxicity of the compound was evaluated on two fibroblast cell lines (MASEF, Mastomys natalensis embryo fibroblast and HEFL-12, human embryo fibroblast) in vitro. The maximum tolerated concentration for both cell lines was 25 micrograms/ml. The results indicate that the compound has potential to be used for treatment of several human and animal parasitic diseases.

African-American mitochondrial DNAs often match mtDNAs found in multiple African ethnic groups

PubMed Central

Ely, Bert; Wilson, Jamie Lee; Jackson, Fatimah; Jackson, Bruce A

2006-01-01

Background Mitochondrial DNA (mtDNA) haplotypes have become popular tools for tracing maternal ancestry, and several companies offer this service to the general public. Numerous studies have demonstrated that human mtDNA haplotypes can be used with confidence to identify the continent where the haplotype originated. Ideally, mtDNA haplotypes could also be used to identify a particular country or ethnic group from which the maternal ancestor emanated. However, the geographic distribution of mtDNA haplotypes is greatly influenced by the movement of both individuals and population groups. Consequently, common mtDNA haplotypes are shared among multiple ethnic groups. We have studied the distribution of mtDNA haplotypes among West African ethnic groups to determine how often mtDNA haplotypes can be used to reconnect Americans of African descent to a country or ethnic group of a maternal African ancestor. The nucleotide sequence of the mtDNA hypervariable segment I (HVS-I) usually provides sufficient information to assign a particular mtDNA to the proper haplogroup, and it contains most of the variation that is available to distinguish a particular mtDNA haplotype from closely related haplotypes. In this study, samples of general African-American and specific Gullah/Geechee HVS-I haplotypes were compared with two databases of HVS-I haplotypes from sub-Saharan Africa, and the incidence of perfect matches recorded for each sample. Results When two independent African-American samples were analyzed, more than half of the sampled HVS-I mtDNA haplotypes exactly matched common haplotypes that were shared among multiple African ethnic groups. Another 40% did not match any sequence in the database, and fewer than 10% were an exact match to a sequence from a single African ethnic group. Differences in the regional distribution of haplotypes were observed in the African database, and the African-American haplotypes were more likely to match haplotypes found in ethnic groups from

Interferon Gamma in African Trypanosome Infections: Friends or Foes?

PubMed

Wu, Hui; Liu, Gongguan; Shi, Meiqing

2017-01-01

African trypanosomes cause fatal infections in both humans and livestock. Interferon gamma (IFN-γ) plays an essential role in resistance to African trypanosomes. However, increasing evidence suggests that IFN-γ, when excessively synthesized, also induces immunopathology, enhancing susceptibility to the infection. Thus, production of IFN-γ must be tightly regulated during infections with African trypanosomes to ensure that a robust immune response is elicited without tissue destruction. Early studies have shown that secretion of IFN-γ is downregulated by interleukin 10 (IL-10). More recently, IL-27 has been identified as a negative regulator of IFN-γ production during African trypanosome infections. In this review, we discuss the current state of our understanding of the role of IFN-γ in African trypanosome infections. We have focused on the cellular source of IFN-γ, its beneficial and detrimental effects, and mechanisms involved in regulation of its production, highlighting some recent advances and offering some perspectives on future directions.

Detecting directional selection in the presence of recent admixture in African-Americans.

PubMed

Lohmueller, Kirk E; Bustamante, Carlos D; Clark, Andrew G

2011-03-01

We investigate the performance of tests of neutrality in admixed populations using plausible demographic models for African-American history as well as resequencing data from African and African-American populations. The analysis of both simulated and human resequencing data suggests that recent admixture does not result in an excess of false-positive results for neutrality tests based on the frequency spectrum after accounting for the population growth in the parental African population. Furthermore, when simulating positive selection, Tajima's D, Fu and Li's D, and haplotype homozygosity have lower power to detect population-specific selection using individuals sampled from the admixed population than from the nonadmixed population. Fay and Wu's H test, however, has more power to detect selection using individuals from the admixed population than from the nonadmixed population, especially when the selective sweep ended long ago. Our results have implications for interpreting recent genome-wide scans for positive selection in human populations. © 2011 by the Genetics Society of America

Detecting Directional Selection in the Presence of Recent Admixture in African-Americans

PubMed Central

Lohmueller, Kirk E.; Bustamante, Carlos D.; Clark, Andrew G.

2011-01-01

We investigate the performance of tests of neutrality in admixed populations using plausible demographic models for African-American history as well as resequencing data from African and African-American populations. The analysis of both simulated and human resequencing data suggests that recent admixture does not result in an excess of false-positive results for neutrality tests based on the frequency spectrum after accounting for the population growth in the parental African population. Furthermore, when simulating positive selection, Tajima's D, Fu and Li's D, and haplotype homozygosity have lower power to detect population-specific selection using individuals sampled from the admixed population than from the nonadmixed population. Fay and Wu's H test, however, has more power to detect selection using individuals from the admixed population than from the nonadmixed population, especially when the selective sweep ended long ago. Our results have implications for interpreting recent genome-wide scans for positive selection in human populations. PMID:21196524

Africans in the American Labor Market

PubMed Central

Elo, Irma T.; Frankenberg, Elizabeth; Gansey, Romeo; Thomas, Duncan

2015-01-01

The number of migrants to the United States from Africa has grown exponentially since the 1930s. For the first time in America’s history, migrants born in Africa are growing at a faster rate than migrants from any other continent. The composition of African-origin migrants has also changed dramatically: in the mid-twentieth century, the majority were white and came from only three countries; but today, about one-fifth are white, and African-origin migrants hail from across the entire continent. Little is known about the implications of these changes for their labor market outcomes in the United States. Using the 2000–2011 waves of the American Community Survey, we present a picture of enormous heterogeneity in labor market participation, sectoral choice, and hourly earnings of male and female migrants by country of birth, race, age at arrival in the United States, and human capital. For example, controlling a rich set of human capital and demographic characteristics, some migrants—such as those from South Africa/Zimbabwe and Cape Verde, who typically enter on employment visas—earn substantial premiums relative to other African-origin migrants. These premiums are especially large among males who arrived after age 18. In contrast, other migrants—such as those from Sudan/Somalia, who arrived more recently, mostly as refugees—earn substantially less than migrants from other African countries. Understanding the mechanisms generating the heterogeneity in these outcomes—including levels of socioeconomic development, language, culture, and quality of education in countries of origin, as well as selectivity of those who migrate—remain important unresolved research questions. PMID:26304845

Trace-metal concentrations in African dust: effects of long-distance transport and implications for human health

USGS Publications Warehouse

Garrison, Virginia; Lamothe, Paul; Morman, Suzette; Plumlee, Geoffrey S.; Gilkes, Robert; Prakongkep, Nattaporn

2010-01-01

The Sahara and Sahel lose billions of tons of eroded mineral soils annually to the Americas and Caribbean, Europe and Asia via atmospheric transport. African dust was collected from a dust source region (Mali, West Africa) and from downwind sites in the Caribbean [Trinidad-Tobago (TT) and U.S. Virgin Islands (VI)] and analysed for 32 trace-elements. Elemental composition of African dust samples was similar to that of average upper continental crust (UCC), with some enrichment or depletion of specific trace-elements. Pb enrichment was observed only in dust and dry deposition samples from the source region and was most likely from local use of leaded gasoline. Dust particles transported long-distances (VI and TT) exhibited increased enrichment of Mo and minor depletion of other elements relative to source region samples. This suggests that processes occurring during long-distance transport of dust produce enrichment/depletion of specific elements. Bioaccessibility of trace-metals in samples was tested in simulated human fluids (gastric and lung) and was found to be greater in downwind than source region samples, for some metals (e.g., As). The large surface to volume ratio of the dust particles (<2.5 µm) at downwind sites may be a factor.

Genetic Variation and Adaptation in Africa: Implications for Human Evolution and Disease

PubMed Central

Gomez, Felicia; Hirbo, Jibril; Tishkoff, Sarah A.

2014-01-01

Because modern humans originated in Africa and have adapted to diverse environments, African populations have high levels of genetic and phenotypic diversity. Thus, genomic studies of diverse African ethnic groups are essential for understanding human evolutionary history and how this leads to differential disease risk in all humans. Comparative studies of genetic diversity within and between African ethnic groups creates an opportunity to reconstruct some of the earliest events in human population history and are useful for identifying patterns of genetic variation that have been influenced by recent natural selection. Here we describe what is currently known about genetic variation and evolutionary history of diverse African ethnic groups. We also describe examples of recent natural selection in African genomes and how these data are informative for understanding the frequency of many genetic traits, including those that cause disease susceptibility in African populations and populations of recent African descent. PMID:24984772

A Regime Legitimacy Explanation of African Peacekeeping

DTIC Science & Technology

2011-09-01

DDR Dearming, Demobilization and Reintegration DRC Democratic Republic of the Congo ECOWAS Economic Community of West African States FAR Forces...Nations Human Development Index xiv THIS PAGE INTENTIONALLY LEFT BLANK 1 I. INTRODUCTION Just 14 years after the genocide of at least a half...increase their moral authority externally by adhering to, or even leading, international norms based on human security. The methodology will be both

Attitudes towards human papillomavirus vaccination among African parents in a city in the north of England: a qualitative study.

PubMed

Mupandawana, Edith T; Cross, Ruth

2016-08-22

Human papillomavirus (HPV) is sexually transmitted and has been conclusively linked to cervical cancer and genital warts. Cervical cancer is attributed to approximately 1100 deaths annually in UK, and is the second most common female cancer globally. It has been suggested that black African women are more predisposed to HPV infection and cervical cancer. A vaccine has been developed to reduce HPV infection, and in the UK, has been offered to 12-13 year old adolescent girls through schools as part of their childhood immunization programme since 2008. Upon programme initiation, it was noted that vaccine uptake was lower in schools where girls from ethnic minority groups were proportionately higher. The study's objectives were to explore factors influencing UK based African parents' acceptance or decline of the HPV vaccine, whether fathers and mothers share similar views pertaining to vaccination and any interfamily tensions resulting from differing views. A qualitative study was conducted with five African couples residing in north England. Face to face semi-structured interviews were carried out. Participants were parents to at least one daughter aged between 8 and 14 years. Recruitment was done through purposive sampling using snowballing. HPV and cervical cancer awareness was generally low, with awareness lower in fathers. HPV vaccination was generally unacceptable among the participants, with fear of promiscuity, infertility and concerns that it's still a new vaccine with yet unknown side effects cited as reasons for vaccine decline. There was HPV risk denial as religion and good cultural upbringing seemed to result in low risk perceptions, with HPV and cervical cancer generally perceived as a white person's disease. Religious values and cultural norms influenced vaccine decision-making, with fathers acting as the ultimate decision makers. Current information about why the vaccine is necessary was generally misunderstood. Tailored information addressing

FcγRIIIa SNPs and haplotypes affect human IgG binding and association with lupus nephritis in African Americans

PubMed Central

Dong, Chaoling; Ptacek, Travis S; Redden, David T; Zhang, Kui; Brown, Elizabeth E.; Edberg, Jeffrey C.; McGwin, Gerald; Alarcón, Graciela S.; Ramsey-Goldman, Rosalind; Reveille, John D.; Vilá, Luis M.; Petri, Michelle; Qin, Aijian; Wu, Jianming; Kimberly, Robert P.

2014-01-01

Objective To investigate whether the FcγRIIIa-66R/H/L polymorphism influences net effective receptor function and to assess if the FCGR3A combined genotypes formed by FcγRIIIa-66R/H/L and FcγRIIIa-176F/V as well as copy number variation (CNV) confer risk for development of SLE and lupus nephritis. Methods FcγRIIIa variants, expressed on A20 IIA1.6 cells, were used in flow cytometry-based human IgG binding assays. FCGR3A SNP and CNV genotypes were determined by Pyrosequencing methodology in a cohort of 1728 SLE patients and 2404 healthy controls. Results The FcγRIIIa-66L/H/R (rs10127939) polymorphism influences ligand binding capacity in the context of the FcγRIIIa-176V (rs396991) allele. The low binding FcγRIIIa-176F allele was associated with SLE nephritis (p = 0.0609) in African Americans but not in European Americans (p > 0.10). Nephritis among African American SLE subjects was associated with FcγRIIIa low binding haplotypes containing the 66R/H/L and 176F variants (p = 0.03) and with low binding genotype combinations (p = 0.002). No association was observed in European American SLE patients. The distribution of FCGR3A CNV was not significantly different between controls and SLE patients with or without nephritis. Conclusion FcγRIIIa-66R/H/L influences ligand binding. The low binding haplotypes formed by 66R/H/L and 176F confer enhanced risk for lupus nephritis in African Americans. FCGR3A CNVs are not associated with SLE or SLE nephritis in either African Americans or European Americans. PMID:24782186

Genetic Determinants Influencing Human Serum Metabolome among African Americans

PubMed Central

Yu, Bing; Zheng, Yan; Alexander, Danny; Morrison, Alanna C.; Coresh, Josef; Boerwinkle, Eric

2014-01-01

Phenotypes proximal to gene action generally reflect larger genetic effect sizes than those that are distant. The human metabolome, a result of multiple cellular and biological processes, are functional intermediate phenotypes proximal to gene action. Here, we present a genome-wide association study of 308 untargeted metabolite levels among African Americans from the Atherosclerosis Risk in Communities (ARIC) Study. Nineteen significant common variant-metabolite associations were identified, including 13 novel loci (p<1.6×10−10). These loci were associated with 7–50% of the difference in metabolite levels per allele, and the variance explained ranged from 4% to 20%. Fourteen genes were identified within the nineteen loci, and four of them contained non-synonymous substitutions in four enzyme-encoding genes (KLKB1, SIAE, CPS1, and NAT8); the other significant loci consist of eight other enzyme-encoding genes (ACE, GATM, ACY3, ACSM2B, THEM4, ADH4, UGT1A, TREH), a transporter gene (SLC6A13) and a polycystin protein gene (PKD2L1). In addition, four potential disease-associated paths were identified, including two direct longitudinal predictive relationships: NAT8 with N-acetylornithine, N-acetyl-1-methylhistidine and incident chronic kidney disease, and TREH with trehalose and incident diabetes. These results highlight the value of using endophenotypes proximal to gene function to discover new insights into biology and disease pathology. PMID:24625756

The application of embodied conversational agents for mentoring African American STEM doctoral students

NASA Astrophysics Data System (ADS)

Gosha, Kinnis

This dissertation presents the design, development and short-term evaluation of an embodied conversational agent designed to mentor human users. An embodied conversational agent (ECA) was created and programmed to mentor African American computer science majors on their decision to pursue graduate study in computing. Before constructing the ECA, previous research in the fields of embodied conversational agents, relational agents, mentorship, telementorship and successful mentoring programs and practices for African American graduate students were reviewed. A survey used to find areas of interest of the sample population. Experts were then interviewed to collect information on those areas of interest and a dialogue for the ECA was constructed based on the interview's transcripts. A between-group, mixed method experiment was conducted with 37 African American male undergraduate computer science majors where one group used the ECA mentor while the other group pursued mentoring advice from a human mentor. Results showed no significant difference between the ECA and human mentor when dealing with career mentoring functions. However, the human mentor was significantly better than the ECA mentor when addressing psychosocial mentoring functions.

Impact of biomedical research on African Americans.

PubMed Central

Harrison, R. W.

2001-01-01

Pharmaceutical development and medical research continues at a fevered pitch. Historically, however, African Americans and other minorities have not been adequately represented in the studies determining a drug's safety and efficacy in humans. A history of misuse in the medical research systems (most notably the Tuskeegee study of syphillis in a population of illiterate, poor black men) have left many blacks wary of the health care system. However, attempts to address the health disparities faced by African Americans must include processes for including wider representation of blacks--as patients as well as investigators--in clinical trials. PMID:12653393

Impact of biomedical research on African Americans.

PubMed

Harrison, R W

2001-03-01

Pharmaceutical development and medical research continues at a fevered pitch. Historically, however, African Americans and other minorities have not been adequately represented in the studies determining a drug's safety and efficacy in humans. A history of misuse in the medical research systems (most notably the Tuskeegee study of syphillis in a population of illiterate, poor black men) have left many blacks wary of the health care system. However, attempts to address the health disparities faced by African Americans must include processes for including wider representation of blacks--as patients as well as investigators--in clinical trials.

Third World adversity: African infant precocity and the role of environment.

PubMed

Saugstad, Letten F

2002-01-01

The war against illiteracy has not been won. The number of illiterates approaches a billion. Most reside in Third World countries--former colonies--where they are caught in a poverty trap of disease, low agricultural production and environmental adversity requiring technology beyond their means. I argue against the commonly held view that this is mainly attributable to the four hundred years of traffic in men. According to the late K.O. Dike, middle men along the African coast barred foreign merchants from the hinterland, and because of this the social, political structure and sovereignty of the African states remained fundamentally unchanged during the period 1400-1807, whereas a few decades after colonisation the socio-political system collapsed and was replaced by a small rich elite and many poor, while resources were taken out of Africa. Present poverty and underdevelopment represent as great a challenge as the trade in slaves. As did the African Middle-Men of that time, African leaders now must unite in an ambitious and confident Pan-African Union demonstrating strength. Western countries should focus on reducing poverty and improving nutrition. This also makes terrorism and legal and illegal migration less likely. Education is important, but the West should not limit its effort to fighting illiteracy but should also support the establishment of institutions for higher education. Africa possessed optimal conditions and an enriched environment for human evolution. African Infant Precocity is a persistent example. The human brain, like other brains, consists 60% of poly-unsaturated fatty acids (Marine-Fat), the rest being water. A sufficient amount is required to secure optimal brain growth. It normalizes brain function, and prevents sudden cardiac and infant death, which have been increasing in Western societies. Humans are unique in having a mismatch between the need for brain food--marine fat--and our common high protein diet. Nowhere is the neglect of the

H3ABioNet, a sustainable pan-African bioinformatics network for human heredity and health in Africa

PubMed Central

Mulder, Nicola J.; Adebiyi, Ezekiel; Alami, Raouf; Benkahla, Alia; Brandful, James; Doumbia, Seydou; Everett, Dean; Fadlelmola, Faisal M.; Gaboun, Fatima; Gaseitsiwe, Simani; Ghazal, Hassan; Hazelhurst, Scott; Hide, Winston; Ibrahimi, Azeddine; Jaufeerally Fakim, Yasmina; Jongeneel, C. Victor; Joubert, Fourie; Kassim, Samar; Kayondo, Jonathan; Kumuthini, Judit; Lyantagaye, Sylvester; Makani, Julie; Mansour Alzohairy, Ahmed; Masiga, Daniel; Moussa, Ahmed; Nash, Oyekanmi; Ouwe Missi Oukem-Boyer, Odile; Owusu-Dabo, Ellis; Panji, Sumir; Patterton, Hugh; Radouani, Fouzia; Sadki, Khalid; Seghrouchni, Fouad; Tastan Bishop, Özlem; Tiffin, Nicki; Ulenga, Nzovu

2016-01-01

The application of genomics technologies to medicine and biomedical research is increasing in popularity, made possible by new high-throughput genotyping and sequencing technologies and improved data analysis capabilities. Some of the greatest genetic diversity among humans, animals, plants, and microbiota occurs in Africa, yet genomic research outputs from the continent are limited. The Human Heredity and Health in Africa (H3Africa) initiative was established to drive the development of genomic research for human health in Africa, and through recognition of the critical role of bioinformatics in this process, spurred the establishment of H3ABioNet, a pan-African bioinformatics network for H3Africa. The limitations in bioinformatics capacity on the continent have been a major contributory factor to the lack of notable outputs in high-throughput biology research. Although pockets of high-quality bioinformatics teams have existed previously, the majority of research institutions lack experienced faculty who can train and supervise bioinformatics students. H3ABioNet aims to address this dire need, specifically in the area of human genetics and genomics, but knock-on effects are ensuring this extends to other areas of bioinformatics. Here, we describe the emergence of genomics research and the development of bioinformatics in Africa through H3ABioNet. PMID:26627985

Lifestyles and routine activities of South African teenagers at risk of being trafficked for involuntary prostitution.

PubMed

Lutya, Thozama Mandisa

2010-12-01

The United Nations estimates that 79% of teenage girls trafficked globally every year are forced into involuntary prostitution. About 247 000 South African children work in exploitative conditions; about 40 000 South African female teenagers work as prostitutes. This paper investigates lifestyles and routine activities of teenagers at risk of being trafficked for involuntary prostitution. The key concepts involuntary prostitution, intergenerational sex and exploitative conditions are defined in relation to the lifestyles and routine activities of South African female teenagers. Human trafficking for involuntary prostitution is described, based on a literature review. Lifestyle exposure and routine activities theories help to explain the potential victimisation of these teenagers in human trafficking for involuntary prostitution. Actual lifestyle and routine activities of South African teenagers and risky behaviours (substance abuse, intergenerational sex and child prostitution) are discussed as factors that make teens vulnerable to such trafficking. This paper recommends that human trafficking prevention efforts (awareness programmes and information campaigns) be directed at places frequented by human traffickers and teenagers in the absence of a capable guardian to reduce victimisation, as traffickers analyse the lifestyles and routine activities of their targets. South Africa should also interrogate entrenched practices such as intergenerational sex.

Comparative Demography of an At-Risk African Elephant Population

PubMed Central

Wittemyer, George; Daballen, David; Douglas-Hamilton, Iain

2013-01-01

Knowledge of population processes across various ecological and management settings offers important insights for species conservation and life history. In regard to its ecological role, charisma and threats from human impacts, African elephants are of high conservation concern and, as a result, are the focus of numerous studies across various contexts. Here, demographic data from an individually based study of 934 African elephants in Samburu, Kenya were summarized, providing detailed inspection of the population processes experienced by the population over a fourteen year period (including the repercussions of recent increases in illegal killing). These data were compared with those from populations inhabiting a spectrum of xeric to mesic ecosystems with variable human impacts. In relation to variability in climate and human impacts (causing up to 50% of recorded deaths among adults), annual mortality in Samburu fluctuated between 1 and 14% and, unrelatedly, natality between 2 and 14% driving annual population increases and decreases. Survivorship in Samburu was significantly lower than other populations with age-specific data even during periods of low illegal killing by humans, resulting in relatively low life expectancy of males (18.9 years) and females (21.8 years). Fecundity (primiparous age and inter-calf interval) were similar to those reported in other human impacted or recovering populations, and significantly greater than that of comparable stable populations. This suggests reproductive effort of African savanna elephants increases in relation to increased mortality (and resulting ecological ramifications) as predicted by life history theory. Further comparison across populations indicated that elongated inter-calf intervals and older ages of reproductive onset were related to age structure and density, and likely influenced by ecological conditions. This study provides detailed empirical data on elephant population dynamics strongly influenced by human

Comparative demography of an at-risk African elephant population.

PubMed

Wittemyer, George; Daballen, David; Douglas-Hamilton, Iain

2013-01-01

Knowledge of population processes across various ecological and management settings offers important insights for species conservation and life history. In regard to its ecological role, charisma and threats from human impacts, African elephants are of high conservation concern and, as a result, are the focus of numerous studies across various contexts. Here, demographic data from an individually based study of 934 African elephants in Samburu, Kenya were summarized, providing detailed inspection of the population processes experienced by the population over a fourteen year period (including the repercussions of recent increases in illegal killing). These data were compared with those from populations inhabiting a spectrum of xeric to mesic ecosystems with variable human impacts. In relation to variability in climate and human impacts (causing up to 50% of recorded deaths among adults), annual mortality in Samburu fluctuated between 1 and 14% and, unrelatedly, natality between 2 and 14% driving annual population increases and decreases. Survivorship in Samburu was significantly lower than other populations with age-specific data even during periods of low illegal killing by humans, resulting in relatively low life expectancy of males (18.9 years) and females (21.8 years). Fecundity (primiparous age and inter-calf interval) were similar to those reported in other human impacted or recovering populations, and significantly greater than that of comparable stable populations. This suggests reproductive effort of African savanna elephants increases in relation to increased mortality (and resulting ecological ramifications) as predicted by life history theory. Further comparison across populations indicated that elongated inter-calf intervals and older ages of reproductive onset were related to age structure and density, and likely influenced by ecological conditions. This study provides detailed empirical data on elephant population dynamics strongly influenced by human

African Ancestry Is Associated with Asthma Risk in African Americans

PubMed Central

Pino-Yanes, María; Wade, Michael S.; Pérez-Méndez, Lina; Kittles, Rick A.; Wang, Deli; Papaiahgari, Srinivas; Ford, Jean G.; Kumar, Rajesh; Garcia, Joe G. N.

2012-01-01

Background Asthma is a common complex condition with clear racial and ethnic differences in both prevalence and severity. Asthma consultation rates, mortality, and severe symptoms are greatly increased in African descent populations of developed countries. African ancestry has been associated with asthma, total serum IgE and lower pulmonary function in African-admixed populations. To replicate previous findings, here we aimed to examine whether African ancestry was associated with asthma susceptibility in African Americans. In addition, we examined for the first time whether African ancestry was associated with asthma exacerbations. Methodology/Principal Findings After filtering for self-reported ancestry and genotype data quality, samples from 1,117 self-reported African-American individuals from New York and Baltimore (394 cases, 481 controls), and Chicago (321 cases followed for asthma exacerbations) were analyzed. Genetic ancestry was estimated based on ancestry informative markers (AIMs) selected for being highly divergent among European and West African populations (95 AIMs for New York and Baltimore, and 66 independent AIMs for Chicago). Among case-control samples, the mean African ancestry was significantly higher in asthmatics than in non-asthmatics (82.0±14.0% vs. 77.8±18.1%, mean difference 4.2% [95% confidence interval (CI):2.0–6.4], p<0.0001). This association remained significant after adjusting for potential confounders (odds ratio: 4.55, 95% CI: 1.69–12.29, p = 0.003). African ancestry failed to show an association with asthma exacerbations (p = 0.965) using a model based on longitudinal data of the number of exacerbations followed over 1.5 years. Conclusions/Significance These data replicate previous findings indicating that African ancestry constitutes a risk factor for asthma and suggest that elevated asthma rates in African Americans can be partially attributed to African genetic ancestry. PMID:22235241

African Language Resource Handbook: A Resource Handbook of the Eighty-two Highest Priority African Languages. Prepublication Edition.

ERIC Educational Resources Information Center

Dwyer, David J.; Yankee, Everyl

A directory of the 82 African languages given high priority for instruction in the United States contains a profile for each language that includes its classification and where it is spoken, the number of speakers, dialect situation, usage, orthography status, and listings of related human and institutional resources for the purpose of…

Impact of African traditional worldviews on climate change adaptation.

PubMed

Sanganyado, Edmond; Teta, Charles; Masiri, Busani

2018-03-01

Recent studies show cultural worldviews are a key determinant of environmental risk perceptions; thus, they could influence climate change adaptation strategies. African traditional worldviews encourage harmony between humans and the environment through a complex metaphysical belief system transmitted through folklore, taboos, and traditional knowledge. However, African traditional worldviews hold a belief in traditional gods that was shown to have a low connectedness to nature and a low willingness to change. In Makueni District, Kenya, 45% of agropastoralists surveyed believed drought was god's plan and could not be changed. In contrast, traditional knowledge, which is shaped by African traditional worldviews, is often used to frame adaptive strategies such as migration, changing modes of production, and planting different crop varieties. Furthermore, traditional knowledge has been used as a complement to science in areas where meteorological data was unavailable. However, the role of African traditional worldviews on climate change adaption remains understudied. Hence, there is a need to systematically establish the influence of African traditional worldviews on climate change risk perception, development of adaptive strategies, and policy formulation and implementation. In this commentary, we discuss the potential impacts of African traditional worldviews on climate change adaptation. Integr Environ Assess Manag 2018;14:189-193. © 2018 SETAC. © 2018 SETAC.

Some reflections on human needs, peace, transculturality and Igbo proverbs in the light of Emmanuel Edeh's African philosophy.

PubMed

Prstačić, Miroslav

2015-03-01

Within the framework of a transcultural, psychodynamic and holistic approach, Edeh's concept of Man as Mma-di (in Igbo language in Nigeria, mma-di = good that is, and mma-ndu = the beauty of Life) is presented as the nucleus of his philosophical articulation from an African metaphysical-anthropological perspective. In this context, some reflections are shown on the following topics: human creativity and peace... of mind, body and soul, as existential values and entity in bioethics; aspects of Edeh's philosophy and his work on the peace in the world; transculturality and Igbo proverbs shaped in form of Japanese Haiku poetry. These reflections emphasize the importance of induced aesthetic mental state in the subject, which derives from biological impulses but from archetypal and symbolic value of the object and continuously enter into a metaphysical experience as a form of life energy and human existential need. In this context, we discover also Edeh's philosophy as a new stimulus for further reflections and research on human life potentials, creativity, peace and Man's cosmic responsibility.

Effect of human rotavirus vaccine on severe diarrhea in African infants.

PubMed

Madhi, Shabir A; Cunliffe, Nigel A; Steele, Duncan; Witte, Desirée; Kirsten, Mari; Louw, Cheryl; Ngwira, Bagrey; Victor, John C; Gillard, Paul H; Cheuvart, Brigitte B; Han, Htay H; Neuzil, Kathleen M

2010-01-28

Rotavirus is the most common cause of severe gastroenteritis among young children worldwide. Data are needed to assess the efficacy of the rotavirus vaccine in African children. We conducted a randomized, placebo-controlled, multicenter trial in South Africa (3166 infants; 64.1% of the total) and Malawi (1773 infants; 35.9% of the total) to evaluate the efficacy of a live, oral rotavirus vaccine in preventing severe rotavirus gastroenteritis. Healthy infants were randomly assigned in a 1:1:1 ratio to receive two doses of vaccine (in addition to one dose of placebo) or three doses of vaccine--the pooled vaccine group--or three doses of placebo at 6, 10, and 14 weeks of age. Episodes of gastroenteritis caused by wild-type rotavirus during the first year of life were assessed through active follow-up surveillance and were graded with the use of the Vesikari scale. A total of 4939 infants were enrolled and randomly assigned to one of the three groups; 1647 infants received two doses of the vaccine, 1651 infants received three doses of the vaccine, and 1641 received placebo. Of the 4417 infants included in the per-protocol efficacy analysis, severe rotavirus gastroenteritis occurred in 4.9% of the infants in the placebo group and in 1.9% of those in the pooled vaccine group (vaccine efficacy, 61.2%; 95% confidence interval, 44.0 to 73.2). Vaccine efficacy was lower in Malawi than in South Africa (49.4% vs. 76.9%); however, the number of episodes of severe rotavirus gastroenteritis that were prevented was greater in Malawi than in South Africa (6.7 vs. 4.2 cases prevented per 100 infants vaccinated per year). Efficacy against all-cause severe gastroenteritis was 30.2%. At least one serious adverse event was reported in 9.7% of the infants in the pooled vaccine group and in 11.5% of the infants in the placebo group. Human rotavirus vaccine significantly reduced the incidence of severe rotavirus gastroenteritis among African infants during the first year of life. (Clinical

Pigmentation in African American skin decreases with skin aging.

PubMed

Chien, Anna L; Suh, Jean; Cesar, Sabrina Sisto Alessi; Fischer, Alexander H; Cheng, Nancy; Poon, Flora; Rainer, Barbara; Leung, Sherry; Martin, Jo; Okoye, Ginette A; Kang, Sewon

2016-10-01

Tristimulus colorimetry, which uses the Commission Internationale de l'Eclairage L*a*b* model to quantify color, has previously been used to analyze pigmentation and erythema in human skin; however, colorimetry of African American skin is not well characterized. We sought to analyze skin color patterns in African Americans and compare them with those of Caucasians. Colorimetry readings of the sun-protected buttock and sun-exposed back of forearm were taken from 40 Caucasian and 43 African American participants from March 2011 through August 2015. African American participants also completed a lifestyle questionnaire. Correlation coefficients, paired t tests, and multivariable linear regression analyses were used for statistical comparisons. Forearm skin was lighter in African Americans ages 65 years and older versus 18 to 30 years (P = .02) but darker in Caucasians ages 65 years or older versus 18 to 30 years (P = .03). In African Americans ages 18 to 30 years, the buttock was darker than the forearm (P < .001), whereas in Caucasians the buttock was lighter than the forearm (P < .001). A lighter forearm than buttock was correlated with supplement use, smoking (ages 18-30 years), and less recreational sun exposure (ages ≥65 years) in African Americans. Our study was limited by the sample size and focal geographic source. Pigmentation patterns regarding sun-protected and sun-exposed areas in African Americans may differ from that of Caucasians, suggesting that other factors may contribute to skin pigmentation in African Americans. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Full-Genome Characterization and Genetic Evolution of West African Isolates of Bagaza Virus

PubMed Central

Faye, Oumar; Diagne, Moussa Moise; Fall, Gamou; Sembene, Mbacke; Sall, Amadou Alpha; Faye, Ousmane

2018-01-01

Bagaza virus is a mosquito-borne flavivirus, first isolated in 1966 in Central African Republic. It has currently been identified in mosquito pools collected in the field in West and Central Africa. Emergence in wild birds in Europe and serological evidence in encephalitis patients in India raise questions on its genetic evolution and the diversity of isolates circulating in Africa. To better understand genetic diversity and evolution of Bagaza virus, we describe the full-genome characterization of 11 West African isolates, sampled from 1988 to 2014. Parameters such as genetic distances, N-glycosylation patterns, recombination events, selective pressures, and its codon adaptation to human genes are assessed. Our study is noteworthy for the observation of N-glycosylation and recombination in Bagaza virus and provides insight into its Indian origin from the 13th century. Interestingly, evidence of Bagaza virus codon adaptation to human house-keeping genes is also observed to be higher than those of other flaviviruses well known in human infections. Genetic variations on genome of West African Bagaza virus could play an important role in generating diversity and may promote Bagaza virus adaptation to other vertebrates and become an important threat in human health. PMID:29652824

Full-Genome Characterization and Genetic Evolution of West African Isolates of Bagaza Virus.

PubMed

Faye, Martin; Faye, Oumar; Diagne, Moussa Moise; Fall, Gamou; Weidmann, Manfred; Sembene, Mbacke; Sall, Amadou Alpha; Faye, Ousmane

2018-04-13

Bagaza virus is a mosquito-borne flavivirus, first isolated in 1966 in Central African Republic. It has currently been identified in mosquito pools collected in the field in West and Central Africa. Emergence in wild birds in Europe and serological evidence in encephalitis patients in India raise questions on its genetic evolution and the diversity of isolates circulating in Africa. To better understand genetic diversity and evolution of Bagaza virus, we describe the full-genome characterization of 11 West African isolates, sampled from 1988 to 2014. Parameters such as genetic distances, N-glycosylation patterns, recombination events, selective pressures, and its codon adaptation to human genes are assessed. Our study is noteworthy for the observation of N-glycosylation and recombination in Bagaza virus and provides insight into its Indian origin from the 13th century. Interestingly, evidence of Bagaza virus codon adaptation to human house-keeping genes is also observed to be higher than those of other flaviviruses well known in human infections. Genetic variations on genome of West African Bagaza virus could play an important role in generating diversity and may promote Bagaza virus adaptation to other vertebrates and become an important threat in human health.

Taking up the cudgels against gay rights? Trends and trajectories in African Christian theologies on homosexuality.

PubMed

van Klinken, Adriaan S; Gunda, Masiiwa Ragies

2012-01-01

Against the background of the HIV epidemic and the intense public controversy on homosexuality in African societies, this article investigates the discourses of academic African Christian theologians on homosexuality. Distinguishing some major strands in African theology, that is, inculturation, liberation, women's and reconstruction theology, the article examines how the central concepts of culture, liberation, justice, and human rights function in these discourses. On the basis of a qualitative analysis of a large number of publications, the article shows that stances of African theologians are varying from silence and rejection to acceptance. Although many African theologians have taken up the cudgels against gay rights, some "dissident voices" break the taboo and develop more inclusive concepts of African identity and African Christianity.

Seasonal Distribution of African Savanna Fires

NASA Technical Reports Server (NTRS)

Cahoon, Donald R.; Stocks, Brian J.; Levine, Joel S.; Cofer, Wesley R., III; O'Neill, Katherine P.

1992-01-01

Savannas consist of a continuous layer of grass interspersed with scattered trees or shrubs, and cover approx. 10 million square kilometers of tropical Africa. African savanna fires, almost all resulting from human activities, may produce as much as a third of the total global emissions from biomass burning. Little is known, however, about the frequency and location of these fires, and the area burned each year. Emissions from African savanna burning are known to be transported over the mid-Atlantic, south Pacific and Indian oceans; but to study fully the transport of regional savanna burning and the seasonality of the atmospheric circulation must be considered simultaneously. Here we describe the temporal and spatial distribution of savanna fires over the entire African continent, as determined from night-time satellite imagery. We find that, contrary to expectations, most fires are left to burn uncontrolled, so that there is no strong diurnal cycle in the fire frequency. The knowledge gained from this study regarding the distribution and variability of fires will aid monitoring of the climatically important trace gases emitted from burning biomass.

Sequence polymorphism at the human apolipoprotein AII gene ( APOA2): unexpected deficit of variation in an African-American sample.

PubMed

Fullerton, Stephanie M; Clark, Andrew G; Weiss, Kenneth M; Taylor, Scott L; Stengård, Jari H; Salomaa, Veikko; Boerwinkle, Eric; Nickerson, Deborah A

2002-07-01

A 3.3-kb region, encompassing the APOA2 gene and 2 kb of 5' and 3' flanking DNA, was re-sequenced in a "core" sample of 24 individuals, sampled without regard to the health from each of three populations: African-Americans from Jackson (Miss., USA), Europeans from North Karelia (Finland), and non-Hispanic European-Americans from Rochester, (Minn., USA). Fifteen variable sites were identified (14 SNPs and one multi-allelic microsatellite, all silent), and these sites segregated as 18 sequence haplotypes (or nine, if SNPs only are considered). The haplotype distribution in the core African-American sample was unusual, with a deficit of particular haplotypes compared with those found in the other two samples, and a significantly (P<0.05) low level of nucleotide diversity relative to patterns of polymorphism and divergence at other human loci. Six of the 14 SNPs, whose variation captured the haplotype structure of the core data, were then genotyped by oligonucleotide ligation assay in an additional 2183 individuals from the same three populations (n=843, n=452, and n=888, respectively). All six sites varied in each of the larger "epidemiological" samples, and together, they defined 19 SNP haplotypes, seven with relative frequencies greater than 1% in the total sample; all of these common haplotypes had been identified earlier in the core re-sequencing survey. Here also, the African-American sample showed significantly lower SNP heterozygosity and haplotype diversity than the other two samples. The deficit of polymorphism is consistent with a population-specific non-neutral increase in the relative frequency of several haplotypes in Jackson.

Prevalence of human papillomavirus genotypes among African women with normal cervical cytology and neoplasia: a systematic review and meta-analysis.

PubMed

Ogembo, Rebecca Kemunto; Gona, Philimon Nyakauru; Seymour, Alaina J; Park, Henry Soo-Min; Bain, Paul A; Maranda, Louise; Ogembo, Javier Gordon

2015-01-01

Several meta-analyses confirmed the five most prevalent human papillomavirus (HPV) strains in women with and without cervical neoplastic diseases are HPV16, 18, 31, 52, and 58. HPV16/18 are the predominant oncogenic genotypes, causing approximately 70% of global cervical cancer cases. The vast majority of the women studied in previous analyses were from Europe, North America, Asia, and most recently Latin America and the Caribbean. Despite the high burden of cervical cancer morbidity and mortality in Africa, a robust meta-analysis of HPV genotype prevalence and distribution in African women is lacking. We systematically searched 14 major databases from inception to August 2013 without language restriction, following the Meta-Analysis of Observational Studies in Epidemiology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Seventy-one studies from 23 African countries were identified after screening 1162 citations and data abstracted and study quality appraised from 195 articles. HPV type-specific prevalence and distribution was estimated from 17,273 cases of women with normal cervical cytology; 1019 women with atypical squamous cells of undetermined significance (ASCUS); 1444 women with low-grade squamous intraepithelial lesion (LSIL); 1571 women with high-grade squamous intraepithelial lesion (HSIL); and 4,067 cases of invasive cervical carcinoma (ICC). Overall prevalence of HPV16/18 were 4.4% and 2.8% of women with normal cytology, 12.0% and 4.4% with ASCUS, 14.5% and 10.0% with LSIL, 31.2% and 13.9% with HSIL, and 49.7% and 18.0% with ICC, respectively. Study limitations include the lack of adequate data from Middle and Northern African regions, and variations in the HPV type-specific sensitivity of different genotyping protocols. To our knowledge, this study is the most comprehensive assessment of the overall prevalence and distribution of HPV genotypes in African women with and without different cervical neoplasias. We

Sex estimation from the patella in an African American population.

PubMed

Peckmann, Tanya R; Fisher, Brooke

2018-02-01

The skull and pelvis have been used for the estimation of sex for unknown human remains. However, in forensic cases where skeletal remains often exhibit postmortem damage and taphonomic changes the patella may be used for the estimation of sex as it is a preservationally favoured bone. The goal of the present research was to derive discriminant function equations from the patella for estimation of sex from an historic African American population. Six parameters were measured on 200 individuals (100 males and 100 females), ranging in age from 20 to 80 years old, from the Robert J. Terry Anatomical Skeleton Collection. The statistical analyses showed that all variables were sexually dimorphic. Discriminant function score equations were generated for use in sex estimation. The overall accuracy of sex classification ranged from 80.0% to 85.0% for the direct method and 80.0%-84.5% for the stepwise method. Overall, when the Spanish and Black South African discriminant functions were applied to the African American population they showed low accuracy rates for sexing the African American sample. However, when the White South African discriminant functions were applied to the African American sample they displayed high accuracy rates for sexing the African American population. The patella was shown to be accurate for sex estimation in the historic African American population. Copyright © 2017 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

An Empirical Examination of Inter-Ethnic Stereotypes: Comparing Asian American and African American Employees.

ERIC Educational Resources Information Center

Gilbert, Jackie; Carr-Ruffino, Norma; Ivancevich, John M.; Lownes-Jackson, Millicent

2003-01-01

Undergraduates (n=127) read career histories (including photographs) of fictitious employees in a 2x2x2 design depicting job type (engineer/human resources), ethnicity (Asian or African American), and gender, with the same qualifications and performance information. African-American males were rated most negatively on work characteristics;…

Molecular characterization of African orthobunyaviruses.

PubMed

Yandoko, E Nakouné; Gribaldo, S; Finance, C; Le Faou, A; Rihn, B H

2007-06-01

The genus Orthobunyavirus is composed of segmented, negative-sense RNA viruses that are responsible for mild to severe human diseases. To date, no molecular studies of bunyaviruses in the genus Orthobunyavirus from central Africa have been reported, and their classification relies on serological testing. Four new primer pairs for RT-PCR amplification and sequencing of the complete genomic small (S) RNA segments of 10 orthobunyaviruses isolated from the Central African Republic and pertaining to five different serogroups have been designed and evaluated. Phylogenetic analysis showed that these 10 viruses belong to the Bunyamwera serogroup. The S segment sequences differ from those of the Bunyamwera virus reference strain by 5-15 % at the nucleotide level, and both overlapping reading frames, encoding the nucleocapsid (N) and non-structural (NS) proteins, were evident in sequenced genomes. This study should improve diagnosis and surveillance of African bunyaviruses.

Kant's Conception of Respect and African American Education Rights

ERIC Educational Resources Information Center

Bynum, Gregory Lewis

2011-01-01

Immanuel Kant envisioned a kind of respect in which one recognizes each human (1) as being not fully comprehensible by any human understanding, (2) as being an end in him- or herself, and (3) as being a potential source of moral law. In this essay, Gregory Lewis Bynum uses this conception of respect as a lens with which to examine African American…

Training trainers in health and human rights: implementing curriculum change in South African health sciences institutions.

PubMed

Ewert, Elena G; Baldwin-Ragaven, Laurel; London, Leslie

2011-07-25

The complicity of the South African health sector in apartheid and the international relevance of human rights as a professional obligation prompted moves to include human rights competencies in the curricula of health professionals in South Africa. A Train-the-Trainers course in Health and Human Rights was established in 1998 to equip faculty members from health sciences institutions nationwide with the necessary skills, attitudes and knowledge to teach human rights to their students. This study followed up participants to determine the extent of curriculum implementation, support needed as well as barriers encountered in integrating human rights into health sciences teaching and learning. A survey including both quantitative and qualitative components was distributed in 2007 to past course participants from 1998-2006 via telephone, fax and electronic communication. Out of 162 past participants, 46 (28%) completed the survey, the majority of whom were still employed in academic settings (67%). Twenty-two respondents (48%) implemented a total of 33 formal human rights courses into the curricula at their institutions. Respondents were nine times more likely (relative risk 9.26; 95% CI 5.14-16.66) to implement human rights education after completing the training. Seventy-two extracurricular activities were offered by 21 respondents, many of whom had successfully implemented formal curricula. Enabling factors for implementation included: prior teaching experience in human rights, general institutional support and the presence of allies - most commonly coworkers as well as deans. Frequently cited barriers to implementation included: budget restrictions, time constraints and perceived apathy of colleagues or students. Overall, respondents noted personal enrichment and optimism in teaching human rights. This Train-the-Trainer course provides the historical context, educational tools, and collective motivation to incorporate human rights educational initiatives at health

Training Trainers in health and human rights: Implementing curriculum change in South African health sciences institutions

PubMed Central

2011-01-01

Background The complicity of the South African health sector in apartheid and the international relevance of human rights as a professional obligation prompted moves to include human rights competencies in the curricula of health professionals in South Africa. A Train-the-Trainers course in Health and Human Rights was established in 1998 to equip faculty members from health sciences institutions nationwide with the necessary skills, attitudes and knowledge to teach human rights to their students. This study followed up participants to determine the extent of curriculum implementation, support needed as well as barriers encountered in integrating human rights into health sciences teaching and learning. Methods A survey including both quantitative and qualitative components was distributed in 2007 to past course participants from 1998-2006 via telephone, fax and electronic communication. Results Out of 162 past participants, 46 (28%) completed the survey, the majority of whom were still employed in academic settings (67%). Twenty-two respondents (48%) implemented a total of 33 formal human rights courses into the curricula at their institutions. Respondents were nine times more likely (relative risk 9.26; 95% CI 5.14-16.66) to implement human rights education after completing the training. Seventy-two extracurricular activities were offered by 21 respondents, many of whom had successfully implemented formal curricula. Enabling factors for implementation included: prior teaching experience in human rights, general institutional support and the presence of allies - most commonly coworkers as well as deans. Frequently cited barriers to implementation included: budget restrictions, time constraints and perceived apathy of colleagues or students. Overall, respondents noted personal enrichment and optimism in teaching human rights. Conclusion This Train-the-Trainer course provides the historical context, educational tools, and collective motivation to incorporate human

Apolipoprotein L1 and kidney disease in African Americans

PubMed Central

Friedman, David J.; Pollak, Martin R.

2016-01-01

Genetic variants in the Apolipoprotein L1 (APOL1) gene cause high rates of kidney disease in African Americans. These variants, found only in individuals with recent African ancestry, confer enhanced innate immunity against African trypanosomes. Though they are among the most powerful disease-causing common variants discovered to date, we are just beginning to understand how they promote kidney injury. Since APOL1 is only present in a few primate species, much of our current knowledge has come from natural experiments in humans and in vitro studies while awaiting the development of transgenic animal models. Understanding more about the function of ApoL1 and how the high-risk variants behave differently from other ApoL1 molecules is a high priority in kidney disease research. PMID:26947522

A continuum of admixture in the Western Hemisphere revealed by the African Diaspora genome

PubMed Central

Mathias, Rasika Ann; Taub, Margaret A.; Gignoux, Christopher R.; Fu, Wenqing; Musharoff, Shaila; O'Connor, Timothy D.; Vergara, Candelaria; Torgerson, Dara G.; Pino-Yanes, Maria; Shringarpure, Suyash S.; Huang, Lili; Rafaels, Nicholas; Boorgula, Meher Preethi; Johnston, Henry Richard; Ortega, Victor E.; Levin, Albert M.; Song, Wei; Torres, Raul; Padhukasahasram, Badri; Eng, Celeste; Mejia-Mejia, Delmy-Aracely; Ferguson, Trevor; Qin, Zhaohui S.; Scott, Alan F.; Yazdanbakhsh, Maria; Wilson, James G.; Marrugo, Javier; Lange, Leslie A.; Kumar, Rajesh; Avila, Pedro C.; Williams, L. Keoki; Watson, Harold; Ware, Lorraine B.; Olopade, Christopher; Olopade, Olufunmilayo; Oliveira, Ricardo; Ober, Carole; Nicolae, Dan L.; Meyers, Deborah; Mayorga, Alvaro; Knight-Madden, Jennifer; Hartert, Tina; Hansel, Nadia N.; Foreman, Marilyn G.; Ford, Jean G.; Faruque, Mezbah U.; Dunston, Georgia M.; Caraballo, Luis; Burchard, Esteban G.; Bleecker, Eugene; Araujo, Maria Ilma; Herrera-Paz, Edwin Francisco; Gietzen, Kimberly; Grus, Wendy E.; Bamshad, Michael; Bustamante, Carlos D.; Kenny, Eimear E.; Hernandez, Ryan D.; Beaty, Terri H.; Ruczinski, Ingo; Akey, Joshua; Campbell, Monica; Chavan, Sameer; Foster, Cassandra; Gao, Li; Horowitz, Edward; Ortiz, Romina; Potee, Joseph; Gao, Jingjing; Hu, Yijuan; Hansen, Mark; Deshpande, Aniket; Locke, Devin P.; Grammer, Leslie; Kim, Kwang-YounA; Schleimer, Robert; De La Vega, Francisco M.; Szpiech, Zachary A.; Oluwole, Oluwafemi; Arinola, Ganiyu; Correa, Adolfo; Musani, Solomon; Chong, Jessica; Nickerson, Deborah; Reiner, Alexander; Maul, Pissamai; Maul, Trevor; Martinez, Beatriz; Meza, Catherine; Ayestas, Gerardo; Landaverde-Torres, Pamela; Erazo, Said Omar Leiva; Martinez, Rosella; Mayorga, Luis F.; Ramos, Hector; Saenz, Allan; Varela, Gloria; Vasquez, Olga Marina; Samms-Vaughan, Maureen; Wilks, Rainford J.; Adegnika, Akim; Ateba-Ngoa, Ulysse; Barnes, Kathleen C.

2016-01-01

The African Diaspora in the Western Hemisphere represents one of the largest forced migrations in history and had a profound impact on genetic diversity in modern populations. To date, the fine-scale population structure of descendants of the African Diaspora remains largely uncharacterized. Here we present genetic variation from deeply sequenced genomes of 642 individuals from North and South American, Caribbean and West African populations, substantially increasing the lexicon of human genomic variation and suggesting much variation remains to be discovered in African-admixed populations in the Americas. We summarize genetic variation in these populations, quantifying the postcolonial sex-biased European gene flow across multiple regions. Moreover, we refine estimates on the burden of deleterious variants carried across populations and how this varies with African ancestry. Our data are an important resource for empowering disease mapping studies in African-admixed individuals and will facilitate gene discovery for diseases disproportionately affecting individuals of African ancestry. PMID:27725671

African American Males. A Critical Link in the African American Family.

ERIC Educational Resources Information Center

Jones, Dionne J., Ed.

African Americans are experiencing extreme stress in the United States, and African-American males appear to suffer the most. The chapters in this volume examine some of the issues confronting African-American men today. They include: (1) "Introduction" (Dionne J. Jones); (2) "Reaffirming Young African American Males: Mentoring and…

IBD Sharing between Africans, Neandertals, and Denisovans

PubMed Central

Povysil, Gundula

2016-01-01

Interbreeding between ancestors of humans and other hominins outside of Africa has been studied intensively, while their common history within Africa still lacks proper attention. However, shedding light on human evolution in this time period about which little is known, is essential for understanding subsequent events outside of Africa. We investigate the genetic relationships of humans, Neandertals, and Denisovans by identifying very short DNA segments in the 1000 Genomes Phase 3 data that these hominins share identical by descent (IBD). By focusing on low frequency and rare variants, we identify very short IBD segments with high confidence. These segments reveal events from a very distant past because shorter IBD segments are presumably older than longer ones. We extracted two types of very old IBD segments that are not only shared among humans, but also with Neandertals and/or Denisovans. The first type contains longer segments that are found primarily in Asians and Europeans where more segments are found in South Asians than in East Asians for both Neandertal and Denisovan. These longer segments indicate complex admixture events outside of Africa. The second type consists of shorter segments that are shared mainly by Africans and therefore may indicate events involving ancestors of humans and other ancient hominins within Africa. Our results from the autosomes are further supported by an analysis of chromosome X, on which segments that are shared by Africans and match the Neandertal and/or Denisovan genome were even more prominent. Our results indicate that interbreeding with other hominins was a common feature of human evolution starting already long before ancestors of modern humans left Africa. PMID:28158547

[Human African trypanosomiasis in an urban area: an emerging problem?].

PubMed

Louis, F J; Bilenge, C M; Simarro, P P; Meso, V Kande; Lucas, P; Jannin, J

2003-08-01

The human African trypanosomiasis is essentially a rural disease. The notification of cases in urban area has always been incidental; either a diagnosis made in town revealed a disease contracted in rural environment or it meant the preservation of a complete epidemiological cycle in a remaining urban micro-focus. In Kinshasa, in Democratic Republic of Congo, about forty cases have been notified each year. All of them came from the nearby foci of Bandundu, Lower Congo and Kasaï. In 1996 the number of cases reached suddenly 254 and today the average annual number comes up to 500 in spite of all the efforts undertaken to fight the disease. A study of cases in 1998 and 1999 shows that patients are essentially distributed in suburbs and that the most affected by the disease are the 15-49 year old ones whose job is related with agricultural or fishing activities. Two phenomena seem to explain this sudden increase: the massive inflow of refugees in outskirts of town coming from provinces where trypanosomiasis is endemic and a major economic crisis throwing out urban population in suburbs living on a subsistence micro-agriculture. These concomitant factors have contributed to the setting up of a trypanosomiasis belt around the capital. Today a strategy has to be reconsidered in order to fight against the disease in the capital itself and to make the medical staff aware of the diagnosis of a disease still unknown in their sanitary district.

The TG/HDL-C ratio does not predict insulin resistance in overweight women of African descent: a study of South African, African American and West African women.

PubMed

Knight, Michael G; Goedecke, Julia H; Ricks, Madia; Evans, Juliet; Levitt, Naomi S; Tulloch-Reid, Marshall K; Sumner, Anne E

2011-01-01

Women of African descent have a high prevalence of diseases caused by insulin resistance. To positively impact cardiometabolic health in Black women, effective screening tests for insulin resistance must be identified. Recently, the TG/HDL-C ratio has been recommended as a tool to predict insulin resistance in overweight people. While the ratio predicts insulin resistance in White women, it is ineffective in African American women. As there are no data for African women, we tested the ability of the TG/HDL-C ratio to predict insulin resistance in Black women from South Africa, West Africa and the United States. For comparison, the ratio was also tested in White women from South Africa. Participants were 801 women (157 Black South African, 382 African American, 119 West African, 143 White South African, age 36 +/- 9y [mean +/- SD]). Standardized scores were created from log-transformed homeostasis model assessment-insulin resistance values from each population. Participants in the upper third of their population distribution were classified as insulin-resistant. To predict insulin resistance by the TC/HDL-C ratio, area under the receiver operating characteristic (AUC-ROC) curve was used and criteria were: 0.50 for no discrimination and > or = 0.70 for acceptable. Seventy-one percent of the Black women were overweight vs 51% of White women (P<.01). In overweight White women, AUC-ROC curve for prediction of insulin resistance by TG/HDL-C was 0.76 +/- 0.06, but below the 0.70 threshold in each group of overweight Black women (Black South African: 0.64 +/- 0.06, African American: 0.66 +/- 0.03, and West African: 0.63 +/- 0.07). Therefore, TG/HDL-C does not predict insulin resistance in overweight African American women and this investigation extends that finding to overweight Black South African and West African women. Resources to identify effective markers of insulin resistance are needed to improve cardiometabolic health in women of African descent.

Africans in America.

ERIC Educational Resources Information Center

Hart, Ayanna; Spangler, Earl

This book introduces African-American history and culture to children. The first Africans in America came from many different regions and cultures, but became united in this country by being black, African, and slaves. Once in America, Africans began a long struggle for freedom which still continues. Slavery, the Civil War, emancipation, and the…

African American parents' HPV vaccination intent and concerns.

PubMed

Sanders Thompson, Vetta L; Arnold, Lauren D; Notaro, Sheri R

2012-02-01

This study describes attitudes and social and environmental factors that affect African American parents' intent to vaccinate their daughters against human papillomavirus (HPV). Thirty African American parents of daughters aged nine to 17 years and no history of HPV infection completed semi-structured interviews. Interviews addressed factors that influenced intent to vaccinate, perception of community norms related to vaccination, vaccination scenarios involving place of vaccination, and vaccination prior to or after the child's initiation of sexual activity. A recurring theme was the influence of physician recommendation on African American parents' intent to obtain HPV vaccination for their daughters. Most parents reported that they could overcome barriers to vaccination, except vaccine costs and lack of insurance. While religious beliefs were important to parents, they reported that they would not interfere with vaccination decisions; fears of early sexuality due to vaccination were limited. The implications of these findings are discussed.

Lower liver-related death in African-American women with human immunodeficiency virus/hepatitis C virus coinfection, compared to Caucasian and Hispanic women.

PubMed

Sarkar, Monika; Bacchetti, Peter; French, Audrey L; Tien, Phyllis; Glesby, Marshall J; Nowicki, Marek; Plankey, Michael; Gange, Stephen; Sharp, Gerald; Minkoff, Howard; Peters, Marion G

2012-11-01

Among individuals with and without concurrent human immunodeficiency virus (HIV), racial/ethnic differences in the natural history of hepatitis C virus (HCV) have been described. African Americans have lower spontaneous HCV clearance than Caucasians, yet slower rates of liver fibrosis once chronically infected. It is not clear how these differences in the natural history of hepatitis C affect mortality, in either HIV-positive or -negative individuals. We conducted a cohort study of HIV/HCV coinfected women followed in the multicenter Women's Interagency HIV Study to determine the association of self-reported race/ethnicity with all-cause and liver-related mortality. Survival analyses were performed using Cox's proportional hazards models. The eligible cohort (n = 794) included 140 Caucasians, 159 Hispanics, and 495 African Americans. There were 438 deaths and 49 liver-related deaths during a median follow-up of 8.9 years and maximum follow-up of 16 years. African-American coinfected women had significantly lower liver-related mortality, compared to Caucasian (hazard ratio [HR], 0.41; 95% confidence interval [CI]: 0.19-0.88; P = 0.022) and Hispanic coinfected women (HR, 0.38; 95% CI: 0.19-0.76; P = 0.006). All-cause mortality was similar between racial/ethnic groups (HRs for all comparisons: 0.82-1.03; log-rank test: P = 0.8). African-American coinfected women were much less likely to die from liver disease, as compared to Caucasians and Hispanics, independent of other causes of death. Future studies are needed to investigate the reasons for this marked racial/ethnic discrepancy in liver-related mortality. Copyright © 2012 American Association for the Study of Liver Diseases.

Tuberculosis Detection by Giant African Pouched Rats

ERIC Educational Resources Information Center

Poling, Alan; Weetjens, Bart; Cox, Christophe; Beyene, Negussie; Durgin, Amy; Mahoney, Amanda

2011-01-01

In recent years, operant discrimination training procedures have been used to teach giant African pouched rats to detect tuberculosis (TB) in human sputum samples. This article summarizes how the rats are trained and used operationally, as well as their performance in studies published to date. Available data suggest that pouched rats, which can…

Adult Illiteracy: The Root of African Underdevelopment

ERIC Educational Resources Information Center

Jogwu, C. N. O.

2010-01-01

All African Nations belong to the category of third world underdeveloped countries of the world. UNDP Human Development Index uses factors like per capita income, health of the people, and educational attainment to classify countries. Adult literacy and gross enrolment ratios are indicators of education status. This paper uses Nigeria, a typical…

Seroprevalence of Leptospira hardjo in cattle and African buffalos in southwestern Uganda.

PubMed

Atherstone, Christine; Picozzi, Kim; Kalema-Zikusoka, Gladys

2014-02-01

Leptospirosis, caused by the spirochete bacterium Leptospira spp. is a zoonosis, distributed worldwide and classified as an emerging infectious disease. Fatal outcomes to leptospiral infection do occur and the disease can cause abortion and other reproductive problems in cattle, goats, and pigs. In humans the symptoms range from subclinical infection to acute febrile illness, pulmonary hemorrhage and renal failure. Leptospirosis has never been officially reported to the World Health Organization (WHO) or the World Animal Health Organization in animals or humans in Uganda. However, favorable ecological conditions and suitable animal hosts can be found within the country. A commercially available enzyme-linked immunosorbent (ELISA) kit was used to screen sera samples from domesticated cattle and African buffalo (Syncerus caffer) at two locations in southwestern Uganda, collected over a 4-year period. Positive samples were found in both cattle and African buffalo samples, from both locations and across the sampling period. Overall seroprevalence was 42.39% in African buffalo and 29.35% in cattle.

Improved survival with HPV among African Americans with oropharyngeal cancer.

PubMed

Worsham, Maria J; Stephen, Josena K; Chen, Kang Mei; Mahan, Meredith; Schweitzer, Vanessa; Havard, Shaleta; Divine, George

2013-05-01

A major limitation of studies reporting a lower prevalence rate of human papilloma virus (HPV) in African American patients with oropharyngeal squamous cell cancer (OPSCC) than Caucasian Americans, with corresponding worse outcomes, was adequate representation of HPV-positive African American patients. This study examined survival outcomes in HPV-positive and HPV-negative African Americans with OPSCC. The study cohort of 121 patients with primary OPSCC had 42% African Americans. Variables of interest included age, race, gender, HPV status, stage, marital status, smoking, treatment, and date of diagnosis. Caucasian Americans are more likely to be HPV positive (OR = 3.28; P = 0.035), as are younger age (age < 50 OR = 7.14; P = 0.023 compared with age > 65) or being married (OR = 3.44; P = 0.016). HPV positivity and being unmarried were associated with being late stage (OR = 3.10; P = 0.047 and OR = 3.23; P = 0.038, respectively). HPV-negative patients had 2.7 times the risk of death as HPV-positive patients (P = 0.004). Overall, the HPV-race groups differed (log-rank P < 0.001), with significantly worse survival for HPV-negative African Americans versus (i) HPV-positive African Americans (HR = 3.44; P = 0.0012); (ii) HPV-positive Caucasian Americans (HR = 3.11; P = < 0.049); and (iii) HPV-negative Caucasian Americans (HR = 2.21; P = 0.049). HPV has a substantial impact on overall survival in African American patients with OPSCC. Among African American patients with OPSCC, HPV-positive patients had better survival than HPV negative. HPV-negative African Americans also did worse than both HPV-positive Caucasian Americans and HPV-negative Caucasian Americans. This study adds to the mounting evidence of HPV as a racially linked sexual behavior life style risk factor impacting survival outcomes for both African American and Caucasian American patients with OPSCC. ©2013 AACR.

Intra-individual metameric variation expressed at the enamel-dentine junction of lower post-canine dentition of South African fossil hominins and modern humans.

PubMed

Pan, Lei; Thackeray, John Francis; Dumoncel, Jean; Zanolli, Clément; Oettlé, Anna; de Beer, Frikkie; Hoffman, Jakobus; Duployer, Benjamin; Tenailleau, Christophe; Braga, José

2017-08-01

The aim of this study is to compare the degree and patterning of inter- and intra-individual metameric variation in South African australopiths, early Homo and modern humans. Metameric variation likely reflects developmental and taxonomical issues, and could also be used to infer ecological and functional adaptations. However, its patterning along the early hominin postcanine dentition, particularly among South African fossil hominins, remains unexplored. Using microfocus X-ray computed tomography (µXCT) and geometric morphometric tools, we studied the enamel-dentine junction (EDJ) morphology and we investigated the intra- and inter-individual EDJ metameric variation among eight australopiths and two early Homo specimens from South Africa, as well as 32 modern humans. Along post-canine dentition, shape changes between metameres represented by relative positions and height of dentine horns, outlines of the EDJ occlusal table are reported in modern and fossil taxa. Comparisons of EDJ mean shapes and multivariate analyses reveal substantial variation in the direction and magnitude of metameric shape changes among taxa, but some common trends can be found. In modern humans, both the direction and magnitude of metameric shape change show increased variability in M 2 -M 3 compared to M 1 -M 2 . Fossil specimens are clustered together showing similar magnitudes of shape change. Along M 2 -M 3 , the lengths of their metameric vectors are not as variable as those of modern humans, but they display considerable variability in the direction of shape change. The distalward increase of metameric variation along the modern human molar row is consistent with the odontogenetic models of molar row structure (inhibitory cascade model). Though much remains to be tested, the variable trends and magnitudes in metamerism in fossil hominins reported here, together with differences in the scale of shape change between modern humans and fossil hominins may provide valuable information

African American and Black Caribbean Feelings of Closeness to Africans

PubMed Central

Thornton, Michael C.; Taylor, Robert Joseph; Chatters, Linda M.; Forsythe-Brown, Ivy

2016-01-01

African American and Black Caribbean relations dominate research on interactions across black ethnic divides. Using National Survey of American Life data, we explore a different aspect of black interethnic attitudes: how close these groups feel toward Africans. African Americans and Black Caribbeans were largely similar in their feelings of closeness to Africans. For Black Caribbeans, younger and male respondents, those reporting higher levels of financial strain, living in the northeast and persons who immigrated to the United States at least 11 years ago, report feeling especially close to Africans. Being male was the only significant correlate among African Americans. The findings are discussed in relation to how race, ethnicity and national origin shape personal identities within the U.S. and their significance for intergroup perceptions. These broader issues warrant further consideration in light of assertions that race as a defining feature of American life and intergroup relations is obsolete. PMID:28943747

The Influence of Life History and Sexual Dimorphism on Entheseal Changes in Modern Humans and African Great Apes

PubMed Central

Milella, Marco

2014-01-01

Entheseal changes have been widely studied with regard to their correlation to biomechanical stress and their usefulness for biocultural reconstructions. However, anthropological and medical studies have demonstrated the marked influence of both age and sex on the development of these features. Studies of entheseal changes are mostly aimed in testing functional hypotheses and are mostly focused on modern humans, with few data available for non-human primates. The lack of comparative studies on the effect of age and sex on entheseal changes represent a gap in our understanding of the evolutionary basis of both development and degeneration of the human musculoskeletal system. The aim of the present work is to compare age trajectories and patterns of sexual dimorphism in entheseal changes between modern humans and African great apes. To this end we analyzed 23 postcranial entheses in a human contemporary identified skeletal collection (N = 484) and compared the results with those obtained from the analysis of Pan (N = 50) and Gorilla (N = 47) skeletal specimens. Results highlight taxon-specific age trajectories possibly linked to differences in life history schedules and phyletic relationships. Robusticity trajectories separate Pan and modern humans from Gorilla, whereas enthesopathic patterns are unique in modern humans and possibly linked to their extended potential lifespan. Comparisons between sexes evidence a decreasing dimorphism in robusticity from Gorilla, to modern humans to Pan, which is likely linked to the role played by size, lifespan and physical activity on robusticity development. The present study confirms previous hypotheses on the possible relevance of EC in the study of life history, pointing moreover to their usefulness in evolutionary studies. PMID:25251439

The influence of life history and sexual dimorphism on entheseal changes in modern humans and African great apes.

PubMed

Milella, Marco

2014-01-01

Entheseal changes have been widely studied with regard to their correlation to biomechanical stress and their usefulness for biocultural reconstructions. However, anthropological and medical studies have demonstrated the marked influence of both age and sex on the development of these features. Studies of entheseal changes are mostly aimed in testing functional hypotheses and are mostly focused on modern humans, with few data available for non-human primates. The lack of comparative studies on the effect of age and sex on entheseal changes represent a gap in our understanding of the evolutionary basis of both development and degeneration of the human musculoskeletal system. The aim of the present work is to compare age trajectories and patterns of sexual dimorphism in entheseal changes between modern humans and African great apes. To this end we analyzed 23 postcranial entheses in a human contemporary identified skeletal collection (N = 484) and compared the results with those obtained from the analysis of Pan (N = 50) and Gorilla (N = 47) skeletal specimens. Results highlight taxon-specific age trajectories possibly linked to differences in life history schedules and phyletic relationships. Robusticity trajectories separate Pan and modern humans from Gorilla, whereas enthesopathic patterns are unique in modern humans and possibly linked to their extended potential lifespan. Comparisons between sexes evidence a decreasing dimorphism in robusticity from Gorilla, to modern humans to Pan, which is likely linked to the role played by size, lifespan and physical activity on robusticity development. The present study confirms previous hypotheses on the possible relevance of EC in the study of life history, pointing moreover to their usefulness in evolutionary studies.

Loci associated with skin pigmentation identified in African populations

PubMed Central

Crawford, Nicholas G.; Kelly, Derek E.; Hansen, Matthew E. B.; Beltrame, Marcia H.; Fan, Shaohua; Bowman, Shanna L.; Jewett, Ethan; Ranciaro, Alessia; Thompson, Simon; Lo, Yancy; Pfeifer, Susanne P.; Jensen, Jeffrey D.; Campbell, Michael C.; Beggs, William; Hormozdiari, Farhad; Mpoloka, Sununguko Wata; Mokone, Gaonyadiwe George; Nyambo, Thomas; Meskel, Dawit Wolde; Belay, Gurja; Haut, Jake; Rothschild, Harriet; Zon, Leonard; Zhou, Yi; Kovacs, Michael A.; Xu, Mai; Zhang, Tongwu; Bishop, Kevin; Sinclair, Jason; Rivas, Cecilia; Elliot, Eugene; Choi, Jiyeon; Li, Shengchao A.; Hicks, Belynda; Burgess, Shawn; Abnet, Christian; Watkins-Chow, Dawn E.; Oceana, Elena; Song, Yun S.; Eskin, Eleazar; Brown, Kevin M.; Marks, Michael S.; Loftus, Stacie K.; Pavan, William J.; Yeager, Meredith; Chanock, Stephen; Tishkoff, Sarah

2017-01-01

Despite the wide range of skin pigmentation in humans, little is known about its genetic basis in global populations. Examining ethnically diverse African genomes, we identify variants in or near SLC24A5, MFSD12, DDB1, TMEM138, OCA2 and HERC2 that are significantly associated with skin pigmentation. Genetic evidence indicates that the light pigmentation variant at SLC24A5 was introduced into East Africa by gene flow from non-Africans. At all other loci, variants associated with dark pigmentation in Africans are identical by descent in southern Asian and Australo-Melanesian populations. Functional analyses indicate that MFSD12 encodes a lysosomal protein that affects melanogenesis in zebrafish and mice, and that mutations in melanocyte-specific regulatory regions near DDB1/TMEM138 correlate with expression of UV response genes under selection in Eurasians. PMID:29025994

HIV/AIDS information by African companies: an empirical analysis.

PubMed

Barako, Dulacha G; Taplin, Ross H; Brown, Alistair M

2010-01-01

This article investigates the extent of Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome Disclosures (HIV/AIDSD) in online annual reports by 200 listed companies from 10 African countries for the year ending 2006. Descriptive statistics reveal a very low level of overall HIV/AIDSD practices with a mean of 6 per cent disclosure, with half (100 out of 200) of the African companies making no disclosures at all. Logistic regression analysis reveals that company size and country are highly significant predictors of any disclosure of HIV/AIDS in annual reports. Profitability is also statistically significantly associated with the extent of disclosure.

Leukoedema: an epidemiological study in white and African Americans.

PubMed

Martin, J L

1997-01-01

Leukoedema, a benign grayish-white lesion which characteristically involves the oral mucosa of humans, was once indicated as a probable precursor to leukoplakia. The author reports an incidence of fifty-three percent in a population of 13,000 white and African Americans who reside in the Southeastern region of the United States. This longitudinal study revealed that the incidence of leukoedema per 1,000 persons increased with age in both ethnic groups up to ages 40-49 and then declined systematically. There was no sex predilection. The occurrence of leukoedema was significantly greater in African Americans.

FIRST AFRICAN CASE OF SPOROTRICHOSIS BEURMANI: TRANSMISSION OF SPOROTRICHOSIS FROM MULE TO MAN

DTIC Science & Technology

indefinite; its animal victims die of exhaustion. However, the classic iodine-iodide treatment for human sporotrichosis was found to be effective. This...particular sporotrichosis is of interest in human clinical study, since it can be transmitted from the animal to a healthy human. In fact, this first African case of human sporotrichosis was a case of mule-to-man infection.

Human Bertiella studeri in Spain, probably of African origin.

PubMed

Galan-Puchades, M T; Fuentes, M V; Mas-Coma, S

1997-06-01

A mature tapeworm and gravid proglottids of Bertiella studeri were reported from the stools of a 33-year-old pregnant Spanish woman. The patient had spent the six months preceding this discovery in Kenya. The evidence suggests a case of parasitism imported to Spain from the African continent. The patient presented no symptoms related to the parasite and the discovery in stools of a number of active, white structures led her to collect them. A morphologic and morphometric description of the material obtained is presented. Mebendazole failed to remove the parasite but niclosamide was effective.

The General Comments on HIV adopted by the African Commission on Human and Peoples' Rights as a tool to advance the sexual and reproductive rights of women in Africa.

PubMed

Durojaye, Ebenezer

2014-12-01

The present article examines the contents and importance of the General Comments adopted by the African Commission on Human and Peoples' Rights on Article 14 (1) (d) and (e) of the Protocol to the African Charter on the Rights of Women in Africa as a tool for advancing women's rights in the context of HIV. Given that discriminatory practices in all facets of life have continued to limit African women's enjoyment of their sexual and reproductive rights and render them susceptible to HIV infection, it becomes vital that African governments adopt appropriate measures to address this challenge. The provisions of the Protocol on the Rights of Women in Africa present great opportunities for this to be realized. The radical and progressive provisions of the Protocol will be of no use to women unless policymakers and other stakeholders have a clear understanding of them and are able to implement them effectively. The adoption of the General Comments is a welcome development, and states and civil society groups must maximize it to advance women's rights. Copyright © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

CLANIMAE: Climatic and Anthropogenic Impacts on African Ecosystems

NASA Astrophysics Data System (ADS)

Verschuren, D.; André, L.; Mahy, G.; Cocquyt, C.; Plisnier, P.-D.; Gelorini, V.; Rumes, B.; Lebrun, J.; Bock, L.; Marchant, R.

2009-04-01

Global studies of historical land use focusing on the large-scale landscape change that can potentially affect global climate (via effects on surface albedo, aerosols, and the carbon cycle) have concluded that the impact of pre-colonial East African cultures on regional ecosystems was limited, due to very low mean population density. This contrasts with the paradigm in East African archaeology and paleoecology that the onset of anthropogenic deforestation started at least 2500 years ago, following the introduction of iron metallurgy by Bantu immigrants. This conflict highlights the present lack of real data on historical climate-environment-human interactions in East Africa, which are eminently relevant to sustainable natural resource management and biodiversity conservation in a future of continued population growth and global climate change. CLANIMAE responds to the urgent need of a correct long-term perspective to today's climate-environment-human interactions in East Africa, by reconstructing simultaneously the histories of past climate change and of vegetation and water-quality changes over the last 2500 years, through multi-disciplinary analysis of dated lake-sediment records. The climate reconstructions integrate information on biological, geochemical and sedimentological indicators of past changes in the water balance of the study lakes, which cover the climatological gradient from (sub-)humid western Uganda to semi-arid eastern Kenya. Reconstruction of past terrestrial vegetation dynamics is based on analyses of fossil plant pollen and phytoliths, plus the fossil spores of fungi associated with the excrements of large domestic animals as indicators of lake use by pastoralists. The evolution of water quality through time is reconstructed using silicon isotopes in diatom algae as proxy indicator for past phytoplankton productivity, and paleoecological analyses of fossil diatoms and aquatic macrophytes, following calibration of diatom and macrophyte species

Determinants of Human Capital Formation and Economic Growth of African Countries

ERIC Educational Resources Information Center

Oketch, Moses O.

2006-01-01

Rapid economic growth and improving living standards have benefited almost all regions of the world since the industrial revolution. Africa stands out as one regional exception. While several factors such as civil wars and rampant corruption have been associated with poor economic performance of the African region in the international community,…

Engineering processes for the African VLBI network

NASA Astrophysics Data System (ADS)

Thondikulam, Venkatasubramani L.; Loots, Anita; Gaylard, Michael

2013-04-01

The African VLBI Network (AVN) is an initiative by the SKA-SA and HartRAO, business units of the National Research Foundation (NRF), Department of Science and Technology (DST), South Africa. The aim is to fill the existing gap of Very Long Baseline Interferometry (VLBI)-capable radio telescopes in the African continent by a combination of new build as well as conversion of large redundant telecommunication antennas through an Inter-Governmental collaborative programme in Science and Technology. The issue of human capital development in the Continent in the techniques of radio astronomy engineering and science is a strong force to drive the project and is expected to contribute significantly to the success of Square Kilometer Array (SKA) in the Continent.

Prevalence of Human Papillomavirus Genotypes among African Women with Normal Cervical Cytology and Neoplasia: A Systematic Review and Meta-Analysis

PubMed Central

Ogembo, Rebecca Kemunto; Gona, Philimon Nyakauru; Seymour, Alaina J.; Park, Henry Soo-Min; Bain, Paul A.; Maranda, Louise; Ogembo, Javier Gordon

2015-01-01

Background Several meta-analyses confirmed the five most prevalent human papillomavirus (HPV) strains in women with and without cervical neoplastic diseases are HPV16, 18, 31, 52, and 58. HPV16/18 are the predominant oncogenic genotypes, causing approximately 70% of global cervical cancer cases. The vast majority of the women studied in previous analyses were from Europe, North America, Asia, and most recently Latin America and the Caribbean. Despite the high burden of cervical cancer morbidity and mortality in Africa, a robust meta-analysis of HPV genotype prevalence and distribution in African women is lacking. Methods and Findings We systematically searched 14 major databases from inception to August 2013 without language restriction, following the Meta-Analysis of Observational Studies in Epidemiology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Seventy-one studies from 23 African countries were identified after screening 1162 citations and data abstracted and study quality appraised from 195 articles. HPV type-specific prevalence and distribution was estimated from 17,273 cases of women with normal cervical cytology; 1019 women with atypical squamous cells of undetermined significance (ASCUS); 1444 women with low-grade squamous intraepithelial lesion (LSIL); 1571 women with high-grade squamous intraepithelial lesion (HSIL); and 4,067 cases of invasive cervical carcinoma (ICC). Overall prevalence of HPV16/18 were 4.4% and 2.8% of women with normal cytology, 12.0% and 4.4% with ASCUS, 14.5% and 10.0% with LSIL, 31.2% and 13.9% with HSIL, and 49.7% and 18.0% with ICC, respectively. Study limitations include the lack of adequate data from Middle and Northern African regions, and variations in the HPV type-specific sensitivity of different genotyping protocols. Conclusions To our knowledge, this study is the most comprehensive assessment of the overall prevalence and distribution of HPV genotypes in African women with and

Identifying tagging SNPs for African specific genetic variation from the African Diaspora Genome

PubMed Central

Johnston, Henry Richard; Hu, Yi-Juan; Gao, Jingjing; O’Connor, Timothy D.; Abecasis, Gonçalo R.; Wojcik, Genevieve L; Gignoux, Christopher R.; Gourraud, Pierre-Antoine; Lizee, Antoine; Hansen, Mark; Genuario, Rob; Bullis, Dave; Lawley, Cindy; Kenny, Eimear E.; Bustamante, Carlos; Beaty, Terri H.; Mathias, Rasika A.; Barnes, Kathleen C.; Qin, Zhaohui S.; Preethi Boorgula, Meher; Campbell, Monica; Chavan, Sameer; Ford, Jean G.; Foster, Cassandra; Gao, Li; Hansel, Nadia N.; Horowitz, Edward; Huang, Lili; Ortiz, Romina; Potee, Joseph; Rafaels, Nicholas; Ruczinski, Ingo; Scott, Alan F.; Taub, Margaret A.; Vergara, Candelaria; Levin, Albert M.; Padhukasahasram, Badri; Williams, L. Keoki; Dunston, Georgia M.; Faruque, Mezbah U.; Gietzen, Kimberly; Deshpande, Aniket; Grus, Wendy E.; Locke, Devin P.; Foreman, Marilyn G.; Avila, Pedro C.; Grammer, Leslie; Kim, Kwang-Youn A.; Kumar, Rajesh; Schleimer, Robert; De La Vega, Francisco M.; Shringarpure, Suyash S.; Musharoff, Shaila; Burchard, Esteban G.; Eng, Celeste; Hernandez, Ryan D.; Pino-Yanes, Maria; Torgerson, Dara G.; Szpiech, Zachary A.; Torres, Raul; Nicolae, Dan L.; Ober, Carole; Olopade, Christopher O; Olopade, Olufunmilayo; Oluwole, Oluwafemi; Arinola, Ganiyu; Song, Wei; Correa, Adolfo; Musani, Solomon; Wilson, James G.; Lange, Leslie A.; Akey, Joshua; Bamshad, Michael; Chong, Jessica; Fu, Wenqing; Nickerson, Deborah; Reiner, Alexander; Hartert, Tina; Ware, Lorraine B.; Bleecker, Eugene; Meyers, Deborah; Ortega, Victor E.; Maul, Pissamai; Maul, Trevor; Watson, Harold; Ilma Araujo, Maria; Riccio Oliveira, Ricardo; Caraballo, Luis; Marrugo, Javier; Martinez, Beatriz; Meza, Catherine; Ayestas, Gerardo; Francisco Herrera-Paz, Edwin; Landaverde-Torres, Pamela; Erazo, Said Omar Leiva; Martinez, Rosella; Mayorga, Alvaro; Mayorga, Luis F.; Mejia-Mejia, Delmy-Aracely; Ramos, Hector; Saenz, Allan; Varela, Gloria; Marina Vasquez, Olga; Ferguson, Trevor; Knight-Madden, Jennifer; Samms-Vaughan, Maureen; Wilks, Rainford J.; Adegnika, Akim; Ateba-Ngoa, Ulysse; Yazdanbakhsh, Maria

2017-01-01

A primary goal of The Consortium on Asthma among African-ancestry Populations in the Americas (CAAPA) is to develop an ‘African Diaspora Power Chip’ (ADPC), a genotyping array consisting of tagging SNPs, useful in comprehensively identifying African specific genetic variation. This array is designed based on the novel variation identified in 642 CAAPA samples of African ancestry with high coverage whole genome sequence data (~30× depth). This novel variation extends the pattern of variation catalogued in the 1000 Genomes and Exome Sequencing Projects to a spectrum of populations representing the wide range of West African genomic diversity. These individuals from CAAPA also comprise a large swath of the African Diaspora population and incorporate historical genetic diversity covering nearly the entire Atlantic coast of the Americas. Here we show the results of designing and producing such a microchip array. This novel array covers African specific variation far better than other commercially available arrays, and will enable better GWAS analyses for researchers with individuals of African descent in their study populations. A recent study cataloging variation in continental African populations suggests this type of African-specific genotyping array is both necessary and valuable for facilitating large-scale GWAS in populations of African ancestry. PMID:28429804

Cranial measures and ancient DNA both show greater similarity of Neandertals to recent modern Eurasians than to recent modern sub-Saharan Africans.

PubMed

Relethford, John H; Smith, Fred H

2018-05-01

Ancient DNA analysis has shown that present-day humans of Eurasian ancestry are more similar to Neandertals than are present-day humans of sub-Saharan African ancestry, reflecting interbreeding after modern humans first left Africa. We use craniometric data to test the hypothesis that the crania of recent modern humans show the same pattern. We computed Mahalanobis squared distances between a published Neandertal centroid based on 37 craniometric traits and each of 2,413 recent modern humans from the Howells global data set (N = 373 sub-Saharan Africans, N = 2,040 individuals of Eurasian descent). The average distance to the Neandertal centroid is significantly lower for Eurasian crania than for sub-Saharan African crania as expected from the findings of ancient DNA (p < 0.001). This result holds when examining distances for separate geographic regions of humans of Eurasian descent (Europeans, Asians, Australasians, Native Americans, and Pacific Islanders). Most of these results are also seen when examining distances partitioning size and shape variation. Our results show that the genetic difference in Neandertal ancestry seen in the DNA of present-day sub-Saharan Africans and Eurasians is also found in patterns of recent modern human craniometric variation. © 2018 Wiley Periodicals, Inc.

Relationship of Pain and Ancestry in African American Women

PubMed Central

Robbins, John A.; Qi, Lihong; Garcia, Lorena; Younger, Jarred W.; Seldin, Michael F.

2015-01-01

Background African Americans are reported to be more sensitive to pain than European Americans. Pain sensitivity has been shown to be genetically linked in animal models and is likely to be in humans. Methods 11,239 self-identified African American post menopausal women enrolled in the Women’s Health Initiative had percentage African ancestry determined by ancestry informative markers, “Pain Construct” measurements and covariate information. They answered 5 questions about specific types and location of pain, such as joint, neck, low back, headache, and urinary. They also answered 2 questions which were used to derive a “Pain Construct”, a measure of general pain scored on a scale of 1 to 100. Associations were tested in linear regression models adjusting for age, self-reported medical conditions, neighborhood socio-economic status, education, and depression. Results In the unadjusted model of the 5 specific types of pain measures, greater pain perception was associated with a higher proportion of African ancestry. However, some of the specific types of pain measures were no longer associated with African ancestry after adjustment for other study covariates. The Pain Construct was statistically significantly associated with African ancestry in both the unadjusted [Beta = −0.132, 95% confidence interval (C I) = −099 – −0.164; r = −0.075, 95% CI −0.056 – −0.093] and the adjusted models (Beta = −0.069 95% CI = −0.04 – 0.10). Conclusions Greater African ancestry was associated with higher levels of self-reported pain although this accounted for only a minor fraction of the overall variation in the Pain Construct. PMID:25752262

Chimpanzees prefer African and Indian music over silence.

PubMed

Mingle, Morgan E; Eppley, Timothy M; Campbell, Matthew W; Hall, Katie; Horner, Victoria; de Waal, Frans B M

2014-10-01

[Correction Notice: An Erratum for this article was reported in Vol 40(4) of Journal of Experimental Psychology: Animal Learning and Cognition (see record 2014-35305-001). For the article, the below files were used to create the audio used in this study. The original West African akan and North Indian raga pieces were used in their entirety and the Japanese taiko piece was used from the 0:19 second mark through the end. The tempo of each piece was adjusted so that they maintained an identical base tempo of 90 beats per minute, then looped to create 40 minutes of continuous music. Additionally, the volume of the music was standardized at 50 dB so that the all music maintained the same average amplitude. All audio manipulations were completed using GarageBand © (Apple Inc.).] All primates have an ability to distinguish between temporal and melodic features of music, but unlike humans, in previous studies, nonhuman primates have not demonstrated a preference for music. However, previous research has not tested the wide range of acoustic parameters present in many different types of world music. The purpose of the present study is to determine the spontaneous preference of common chimpanzees (Pan troglodytes) for 3 acoustically contrasting types of world music: West African akan, North Indian raga, and Japanese taiko. Sixteen chimpanzees housed in 2 groups were exposed to 40 min of music from a speaker placed 1.5 m outside the fence of their outdoor enclosure; the proximity of each subject to the acoustic stimulus was recorded every 2 min. When compared with controls, subjects spent significantly more time in areas where the acoustic stimulus was loudest in African and Indian music conditions. This preference for African and Indian music could indicate homologies in acoustic preferences between nonhuman and human primates. .

A Local Response to the Global Human Rights Standard: The "Ubuntu" Perspective on Human Dignity

ERIC Educational Resources Information Center

Murithi, Tim

2007-01-01

Some African leaders have made the argument that the promotion of an international human rights standard is a strategy that is used and abused by hypocritical Western governments to justify their intervention into the affairs of African countries. The tacit objective behind this articulation is the desire to avoid an external evaluation or…

A Nosocomial Outbreak of Human Monkeypox in the Central African Republic

PubMed Central

Nakoune, Emmanuel; Lampaert, Emmanuel; Ndjapou, Séverin Gervais; Janssens, Carole; Zuniga, Isabel; Van Herp, Michel; Fongbia, Jean Paul; Koyazegbe, Thomas Daquin; Selekon, Benjamin; Komoyo, Giscard Francis; Garba-Ouangole, Sandra Miriella; Manengu, Casimir; Manuguerra, Jean-Claude; Kazanji, Mirdad; Gessain, Antoine; Berthet, Nicolas

2017-01-01

Abstract An outbreak of familial monkeypox occurred in the Central African Republic in 2015/2016 by 3 transmission modes: familial, health care–related, and transport-related. Ten people (3 children and 7 adults) were infected. Most presented with cutaneous lesions and fever, and 2 children died. The viral strain responsible was a Zaire genotype strain. PMID:29732376

Giving Our Daughters What We Never Received: African American Mothers Discussing Sexual Health with Their Preadolescent Daughters

ERIC Educational Resources Information Center

Grigsby, Sheila R.

2018-01-01

African American girls experience disparate rates of pregnancy and acquisition of sexually transmitted infections, including human immunodeficiency virus, when compared to their non-Hispanic White counterparts. Among African American girls, current pregnancy rates are equal to the national crisis levels of teen pregnancy reported in 1990. This…

Pregnancy, parturition and preeclampsia in women of African ancestry.

PubMed

Nakimuli, Annettee; Chazara, Olympe; Byamugisha, Josaphat; Elliott, Alison M; Kaleebu, Pontiano; Mirembe, Florence; Moffett, Ashley

2014-06-01

Maternal and associated neonatal mortality rates in sub-Saharan Africa remain unacceptably high. In Mulago Hospital (Kampala, Uganda), 2 major causes of maternal death are preeclampsia and obstructed labor and their complications, conditions occurring at the extremes of the birthweight spectrum, a situation encapsulated as the obstetric dilemma. We have questioned whether the prevalence of these disorders occurs more frequently in indigenous African women and those with African ancestry elsewhere in the world by reviewing available literature. We conclude that these women are at greater risk of preeclampsia than other racial groups. At least part of this susceptibility seems independent of socioeconomic status and likely is due to biological or genetic factors. Evidence for a genetic contribution to preeclampsia is discussed. We go on to propose that the obstetric dilemma in humans is responsible for this situation and discuss how parturition and birthweight are subject to stabilizing selection. Other data we present also suggest that there are particularly strong evolutionary selective pressures operating during pregnancy and delivery in Africans. There is much greater genetic diversity and less linkage disequilibrium in Africa, and the genes responsible for regulating birthweight and placentation may therefore be easier to define than in non-African cohorts. Inclusion of African women into research on preeclampsia is an essential component in tackling this major disparity of maternal health. Copyright © 2014 Mosby, Inc. All rights reserved.

Pregnancy, parturition and preeclampsia in women of African ancestry

PubMed Central

Nakimuli, Annettee; Chazara, Olympe; Byamugisha, Josaphat; Elliott, Alison M.; Kaleebu, Pontiano; Mirembe, Florence; Moffett, Ashley

2014-01-01

Maternal and associated neonatal mortality rates in sub-Saharan Africa remain unacceptably high. In Mulago Hospital (Kampala, Uganda), 2 major causes of maternal death are preeclampsia and obstructed labor and their complications, conditions occurring at the extremes of the birthweight spectrum, a situation encapsulated as the obstetric dilemma. We have questioned whether the prevalence of these disorders occurs more frequently in indigenous African women and those with African ancestry elsewhere in the world by reviewing available literature. We conclude that these women are at greater risk of preeclampsia than other racial groups. At least part of this susceptibility seems independent of socioeconomic status and likely is due to biological or genetic factors. Evidence for a genetic contribution to preeclampsia is discussed. We go on to propose that the obstetric dilemma in humans is responsible for this situation and discuss how parturition and birthweight are subject to stabilizing selection. Other data we present also suggest that there are particularly strong evolutionary selective pressures operating during pregnancy and delivery in Africans. There is much greater genetic diversity and less linkage disequilibrium in Africa, and the genes responsible for regulating birthweight and placentation may therefore be easier to define than in non-African cohorts. Inclusion of African women into research on preeclampsia is an essential component in tackling this major disparity of maternal health. PMID:24184340

Conversation on African Music.

ERIC Educational Resources Information Center

Saunders, Leslie R.

1985-01-01

A voice and music education teacher at the University of Lagos, Nigeria, talks about African music in this interview. Topics discussed include differences between African and Western music, African melody, rules for composing African music, the theory of counterpoint, and the popularity of classical composers in Nigeria. (RM)

The African Genome Variation Project shapes medical genetics in Africa

NASA Astrophysics Data System (ADS)

Gurdasani, Deepti; Carstensen, Tommy; Tekola-Ayele, Fasil; Pagani, Luca; Tachmazidou, Ioanna; Hatzikotoulas, Konstantinos; Karthikeyan, Savita; Iles, Louise; Pollard, Martin O.; Choudhury, Ananyo; Ritchie, Graham R. S.; Xue, Yali; Asimit, Jennifer; Nsubuga, Rebecca N.; Young, Elizabeth H.; Pomilla, Cristina; Kivinen, Katja; Rockett, Kirk; Kamali, Anatoli; Doumatey, Ayo P.; Asiki, Gershim; Seeley, Janet; Sisay-Joof, Fatoumatta; Jallow, Muminatou; Tollman, Stephen; Mekonnen, Ephrem; Ekong, Rosemary; Oljira, Tamiru; Bradman, Neil; Bojang, Kalifa; Ramsay, Michele; Adeyemo, Adebowale; Bekele, Endashaw; Motala, Ayesha; Norris, Shane A.; Pirie, Fraser; Kaleebu, Pontiano; Kwiatkowski, Dominic; Tyler-Smith, Chris; Rotimi, Charles; Zeggini, Eleftheria; Sandhu, Manjinder S.

2015-01-01

Given the importance of Africa to studies of human origins and disease susceptibility, detailed characterization of African genetic diversity is needed. The African Genome Variation Project provides a resource with which to design, implement and interpret genomic studies in sub-Saharan Africa and worldwide. The African Genome Variation Project represents dense genotypes from 1,481 individuals and whole-genome sequences from 320 individuals across sub-Saharan Africa. Using this resource, we find novel evidence of complex, regionally distinct hunter-gatherer and Eurasian admixture across sub-Saharan Africa. We identify new loci under selection, including loci related to malaria susceptibility and hypertension. We show that modern imputation panels (sets of reference genotypes from which unobserved or missing genotypes in study sets can be inferred) can identify association signals at highly differentiated loci across populations in sub-Saharan Africa. Using whole-genome sequencing, we demonstrate further improvements in imputation accuracy, strengthening the case for large-scale sequencing efforts of diverse African haplotypes. Finally, we present an efficient genotype array design capturing common genetic variation in Africa.

The African Genome Variation Project shapes medical genetics in Africa.

PubMed

Gurdasani, Deepti; Carstensen, Tommy; Tekola-Ayele, Fasil; Pagani, Luca; Tachmazidou, Ioanna; Hatzikotoulas, Konstantinos; Karthikeyan, Savita; Iles, Louise; Pollard, Martin O; Choudhury, Ananyo; Ritchie, Graham R S; Xue, Yali; Asimit, Jennifer; Nsubuga, Rebecca N; Young, Elizabeth H; Pomilla, Cristina; Kivinen, Katja; Rockett, Kirk; Kamali, Anatoli; Doumatey, Ayo P; Asiki, Gershim; Seeley, Janet; Sisay-Joof, Fatoumatta; Jallow, Muminatou; Tollman, Stephen; Mekonnen, Ephrem; Ekong, Rosemary; Oljira, Tamiru; Bradman, Neil; Bojang, Kalifa; Ramsay, Michele; Adeyemo, Adebowale; Bekele, Endashaw; Motala, Ayesha; Norris, Shane A; Pirie, Fraser; Kaleebu, Pontiano; Kwiatkowski, Dominic; Tyler-Smith, Chris; Rotimi, Charles; Zeggini, Eleftheria; Sandhu, Manjinder S

2015-01-15

Given the importance of Africa to studies of human origins and disease susceptibility, detailed characterization of African genetic diversity is needed. The African Genome Variation Project provides a resource with which to design, implement and interpret genomic studies in sub-Saharan Africa and worldwide. The African Genome Variation Project represents dense genotypes from 1,481 individuals and whole-genome sequences from 320 individuals across sub-Saharan Africa. Using this resource, we find novel evidence of complex, regionally distinct hunter-gatherer and Eurasian admixture across sub-Saharan Africa. We identify new loci under selection, including loci related to malaria susceptibility and hypertension. We show that modern imputation panels (sets of reference genotypes from which unobserved or missing genotypes in study sets can be inferred) can identify association signals at highly differentiated loci across populations in sub-Saharan Africa. Using whole-genome sequencing, we demonstrate further improvements in imputation accuracy, strengthening the case for large-scale sequencing efforts of diverse African haplotypes. Finally, we present an efficient genotype array design capturing common genetic variation in Africa.

Drivers of extinction risk in African mammals: the interplay of distribution state, human pressure, conservation response and species biology.

PubMed

Di Marco, Moreno; Buchanan, Graeme M; Szantoi, Zoltan; Holmgren, Milena; Grottolo Marasini, Gabriele; Gross, Dorit; Tranquilli, Sandra; Boitani, Luigi; Rondinini, Carlo

2014-01-01

Although conservation intervention has reversed the decline of some species, our success is outweighed by a much larger number of species moving towards extinction. Extinction risk modelling can identify correlates of risk and species not yet recognized to be threatened. Here, we use machine learning models to identify correlates of extinction risk in African terrestrial mammals using a set of variables belonging to four classes: species distribution state, human pressures, conservation response and species biology. We derived information on distribution state and human pressure from satellite-borne imagery. Variables in all four classes were identified as important predictors of extinction risk, and interactions were observed among variables in different classes (e.g. level of protection, human threats, species distribution ranges). Species biology had a key role in mediating the effect of external variables. The model was 90% accurate in classifying extinction risk status of species, but in a few cases the observed and modelled extinction risk mismatched. Species in this condition might suffer from an incorrect classification of extinction risk (hence require reassessment). An increased availability of satellite imagery combined with improved resolution and classification accuracy of the resulting maps will play a progressively greater role in conservation monitoring.

The African Connection

ERIC Educational Resources Information Center

Oguntoyinbo, Lekan

2012-01-01

From student and faculty exchanges to joint research projects, U.S. universities maintain a broad spectrum of collaborative relationships with African universities. It's unclear how many U.S. colleges and universities have partnerships with African universities. The African Studies Association, an organization of scholars, doesn't keep that kind…

Global-change vulnerability of a key plant resource, the African palms.

PubMed

Blach-Overgaard, Anne; Balslev, Henrik; Dransfield, John; Normand, Signe; Svenning, Jens-Christian

2015-07-27

Palms are keystone species in tropical ecosystems and provide essential ecosystem services to rural people worldwide. However, many palm species are threatened by habitat loss and over-exploitation. Furthermore, palms are sensitive to climate and thus vulnerable to future climate changes. Here, we provide a first quantitative assessment of the future risks to the African palm flora, finding that African palm species on average may experience a decline in climatic suitability in >70% of their current ranges by 2080. This suitability loss may, however, be almost halved if migration to nearby climatically suitable sites succeeds. Worryingly, 42% of the areas with 80-100% of species losing climate suitability are also characterized by high human population density (HPD). By 2080, >90% of all African palm species' ranges will likely occur at HPDs leading to increased risks of habitat loss and overexploitation. Additionally, up to 87% of all species are predicted to lose climatic suitability within current protected areas (PAs) by 2080. In summary, a major plant component of tropical ecosystems and provider of ecosystem services to rural populations will face strongly increased pressures from climate change and human populations in the near future.

Estimating and mapping the population at risk of sleeping sickness.

PubMed

Simarro, Pere P; Cecchi, Giuliano; Franco, José R; Paone, Massimo; Diarra, Abdoulaye; Ruiz-Postigo, José Antonio; Fèvre, Eric M; Mattioli, Raffaele C; Jannin, Jean G

2012-01-01

Human African trypanosomiasis (HAT), also known as sleeping sickness, persists as a public health problem in several sub-Saharan countries. Evidence-based, spatially explicit estimates of population at risk are needed to inform planning and implementation of field interventions, monitor disease trends, raise awareness and support advocacy. Comprehensive, geo-referenced epidemiological records from HAT-affected countries were combined with human population layers to map five categories of risk, ranging from "very high" to "very low," and to estimate the corresponding at-risk population. Approximately 70 million people distributed over a surface of 1.55 million km(2) are estimated to be at different levels of risk of contracting HAT. Trypanosoma brucei gambiense accounts for 82.2% of the population at risk, the remaining 17.8% being at risk of infection from T. b. rhodesiense. Twenty-one million people live in areas classified as moderate to very high risk, where more than 1 HAT case per 10,000 inhabitants per annum is reported. Updated estimates of the population at risk of sleeping sickness were made, based on quantitative information on the reported cases and the geographic distribution of human population. Due to substantial methodological differences, it is not possible to make direct comparisons with previous figures for at-risk population. By contrast, it will be possible to explore trends in the future. The presented maps of different HAT risk levels will help to develop site-specific strategies for control and surveillance, and to monitor progress achieved by ongoing efforts aimed at the elimination of sleeping sickness.

Colonialism, Biko and AIDS: reflections on the principle of beneficence in South African medical ethics.

PubMed

Braude, Hillel David

2009-06-01

This paper examines the principle of beneficence in the light of moral and epistemological concerns that have crystallized in the South African context around clinical care. Three examples from the South African experience affecting the development of bioethics are examined: medical colonialism, the death in detention of Steve Biko, and the HIV/AIDS epidemic. Michael Gelfand's book [(1948). The sick African: a clinical study. Cape Town: Stewart Printing Company.] on African medical conditions captures the ambiguous nature of colonial medicine that linked genuine medical treatment with the civilizing mission. Biko's death was a key historical event that deeply implicated the medical profession under apartheid. The present HIV/AIDS epidemic presents the gravest social and political crisis for South African society. All three experiences influence the meaning and relevance of beneficence as a bioethics principle in the South African context. This paper argues for a South African bioethics informed by a critical humanism that takes account of the colonial past, and that does not model itself on an "original wound" or negation, but on positive care-giving practices.

African Scientific Network: A model to enhance scientific research in developing countries

NASA Astrophysics Data System (ADS)

Kebede, Abebe

2002-03-01

Africa has over 350 higher education institutions with a variety of experiences and priorities. The primary objectives of these institutions are to produce white-collar workers, teachers, and the work force for mining, textiles, and agricultural industries. The state of higher education and scientific research in Africa have been discussed in several conferences. The proposals that are generated by these conferences advocate structural changes in higher education, North-South institutional linkages, mobilization of the African Diaspora and funding. We propose a model African Scientific Network that would facilitate and enhance international scientific partnerships between African scientists and their counterparts elsewhere. A recent article by James Lamout (Financial Times, August 2, 2001) indicates that emigration from South Africa alone costs $8.9 billion in lost human resources. The article also stated that every year 23,000 graduates leave Africa for opportunities overseas, mainly in Europe, leaving only 20,000 scientists and engineers serving over 600 million people. The International Organization for Migration states that the brain drain of highly skilled professionals from Africa is making economic growth and poverty alleviation impossible across the continent. In our model we will focus on a possible networking mechanism where the African Diaspora will play a major role in addressing the financial and human resources needs of higher education in Africa

Factors influencing the migration of West African health professionals

PubMed Central

Lowe, Mat; Chen, Duan-Rung

2016-01-01

Introduction The West African health sector is characterized by a human resource base lacking in numbers and specialized skills. Among the contributory factors to this lack of human resource for health workforce include but not limited to the migration of health professionals. Methods This cross-sectional survey targeted 118 young professionals who have participated in the Young Professional Internship Program (YPIP) of the West African Health Organization (WAHO), from (2005-2013). It inquired about their socio-demographic characteristics associated with migration and reasons for going to their preferred or most likely destinations through online survey. Results Of the 118 young professionals, 100 responded to the online survey, of which (28%) have migrated and (72%) did not migrate. Migration was more common among males and those (age≤31 years old), single with high dependency level and no previous work experience. Having a medical profession and being posted to urban or semi-urban area was also associated with their emigration. Their most important reasons for going to preferred or most likely destinations were to have fair level of workload, job promotion and limited occupational risks. Conclusion This finding suggests that the migration of health professionals is situation dependent, mediated by basic socio-demographic variables and work related conditions. These issues have implications for curbing the brain drain potential of health professionals in the West African health sector. PMID:27800092

Brazilian Cerrado Qualea grandiflora Mart. Leaves Exhibit Antiplasmodial and Trypanocidal Activities In vitro

PubMed Central

Cordeiro, Thuany de Moura; Borghetti, Fabian; Caldas Oliveira, Sarah C.; Bastos, Izabela Marques Dourado; de Santana, Jaime Martins; Grellier, Philippe; Charneau, Sébastien

2017-01-01

Background: The rapid spread of drug-resistant strains of protozoan parasites required the urgent need for new effective drugs. Natural products offer a variety of chemical structures, which make them a valuable source of lead compounds for the development of such new drugs. Cerrado is the second largest biome in Brazil and has the richest flora of all the world savannahs. We selected Qualea grandiflora, a plant species known for its proprieties in folk medicine and its antibacterial activity. Objective: However, its antiprotozoal activity was not yet explored. Materials and Methods: We investigated the activities of fractions from the ethyl acetate extract of Q. grandiflora leaves against human life forms of Plasmodium falciparum, Trypanosoma cruzi, and Trypanosoma brucei gambiense, and for its cytotoxicity upon the rat L6-myoblast cell line. Ten fractions were produced by ethyl acetate:hexane chromatography. Results and Conclusion: The fractions showed no cytotoxicity against L-6 cells (IC50 > 100 μg/mL) and no hemolysis propriety. Three fractions had a moderate activity against P. falciparum, anyone was active against T. cruzi but four fractions demonstrated a high activity against bloodstream forms of T. brucei gambiense (8.0< IC50 <15 μg/mL). Identification and characterization of the active compounds are currently under investigation. SUMMARY Qualea grandiflora is an endemic tree of the Brazilian Cerrado, which presents medicinal propertiesTen fractions of the ethyl acetate extract of Q. grandiflora leaves were assessed against Plasmodium falciparum, Trypanosoma Cruzi, and Trypanosoma brucei gambienseNo fraction showed relevant cytotoxicity and hemolysis activityAll the fractions presented antiplasmodial and trypanocidal activitiesThree fractions with moderate antiplasmodial activity (49< IC50 <56 μg/mL)Four fractions with high activity against bloodstream forms of T. brucei gambiense (8.0< IC50 <15 μg/mL). Abbreviations used: CQ: Chloroquine, DMSO

Brazilian Cerrado Qualea grandiflora Mart. Leaves Exhibit Antiplasmodial and Trypanocidal Activities In vitro.

PubMed

Cordeiro, Thuany de Moura; Borghetti, Fabian; Caldas Oliveira, Sarah C; Bastos, Izabela Marques Dourado; de Santana, Jaime Martins; Grellier, Philippe; Charneau, Sébastien

2017-01-01

The rapid spread of drug-resistant strains of protozoan parasites required the urgent need for new effective drugs. Natural products offer a variety of chemical structures, which make them a valuable source of lead compounds for the development of such new drugs. Cerrado is the second largest biome in Brazil and has the richest flora of all the world savannahs. We selected Qualea grandiflora , a plant species known for its proprieties in folk medicine and its antibacterial activity. However, its antiprotozoal activity was not yet explored. We investigated the activities of fractions from the ethyl acetate extract of Q. grandiflora leaves against human life forms of Plasmodium falciparum , Trypanosoma cruzi , and Trypanosoma brucei gambiense , and for its cytotoxicity upon the rat L6-myoblast cell line. Ten fractions were produced by ethyl acetate:hexane chromatography. The fractions showed no cytotoxicity against L-6 cells (IC 50 > 100 μg/mL) and no hemolysis propriety. Three fractions had a moderate activity against P. falciparum , anyone was active against T. cruzi but four fractions demonstrated a high activity against bloodstream forms of T. brucei gambiense (8.0< IC 50 <15 μg/mL). Identification and characterization of the active compounds are currently under investigation. Qualea grandiflora is an endemic tree of the Brazilian Cerrado, which presents medicinal propertiesTen fractions of the ethyl acetate extract of Q. grandiflora leaves were assessed against Plasmodium falciparum , Trypanosoma Cruzi , and Trypanosoma brucei gambiense No fraction showed relevant cytotoxicity and hemolysis activityAll the fractions presented antiplasmodial and trypanocidal activitiesThree fractions with moderate antiplasmodial activity (49< IC 50 <56 μg/mL)Four fractions with high activity against bloodstream forms of T. brucei gambiense (8.0< IC 50 <15 μg/mL). Abbreviations used: CQ: Chloroquine, DMSO: Dimethyl sulfoxide, HEPES: 4-(2-hydroxyethyl)-1

Fcγ receptor IIIa single-nucleotide polymorphisms and haplotypes affect human IgG binding and are associated with lupus nephritis in African Americans.

PubMed

Dong, Chaoling; Ptacek, Travis S; Redden, David T; Zhang, Kui; Brown, Elizabeth E; Edberg, Jeffrey C; McGwin, Gerald; Alarcón, Graciela S; Ramsey-Goldman, Rosalind; Reveille, John D; Vilá, Luis M; Petri, Michelle; Qin, Aijian; Wu, Jianming; Kimberly, Robert P

2014-05-01

To investigate whether the Fcγ receptor IIIa-66L/R/H (FcγRIIIa-66L/R/H) polymorphism influences net effective receptor function and to assess if the FCGR3A combined genotypes formed by FcγRIIIa-66L/R/H and FcγRIIIa-176F/V, as well as copy number variation (CNV), confer risk of developing systemic lupus erythematosus (SLE) and lupus nephritis. FcγRIIIa variants, expressed on A20 IIA1.6 cells, were used in flow cytometry-based human IgG-binding assays. Using Pyrosequencing methodology, FCGR3A single-nucleotide polymorphism and CNV genotypes were determined in a cohort of 1,728 SLE patients and 2,404 healthy controls. The FcγRIIIa-66L/R/H (rs10127939) polymorphism influenced ligand binding capacity in the presence of the FcγRIIIa-176V (rs396991) allele. There was a trend toward an association of the low-binding FcγRIIIa-176F allele with lupus nephritis among African Americans (P = 0.0609) but not among European Americans (P > 0.10). Nephritis among African American patients with SLE was associated with FcγRIIIa low-binding haplotypes containing the 66L/R/H and 176F variants (P = 0.03) and with low-binding genotype combinations (P = 0.002). No association was observed among European American patients with SLE. The distribution of FCGR3A CNV was not significantly different among controls and SLE patients with or without nephritis. FcγRIIIa-66L/R/H influences ligand binding. The low-binding haplotypes formed by 66L/R/H and 176F confer enhanced risk of lupus nephritis in African Americans. FCGR3A CNVs are not associated with SLE or lupus nephritis in either African Americans or European Americans. Copyright © 2014 by the American College of Rheumatology.

Poaching and human encroachment reverse recovery of African savannah elephants in south-east Angola despite 14 years of peace.

PubMed

Schlossberg, Scott; Chase, Michael J; Griffin, Curtice R

2018-01-01

With populations of African savannah elephants (Loxodonta africana) declining across the continent, assessing the status of individual elephant populations is important for conservation. Angola's elephant population represents a key linkage between the larger populations of Namibia and Botswana. Elephants in Angola were decimated during the 1975-2002 Angolan civil war, but a 2005 survey showed that populations were recolonizing former habitats. Between 2005 and 2015, no research was permitted on elephants in Angola, but elsewhere in Africa many elephant populations experienced a poaching crisis. In 2015, we were able to resume elephant research in Angola. We used aerial surveys and satellite monitoring of collared elephants to determine the current status of elephant populations in Angola and to learn how human populations may be affecting elephant habitat usage. The aerial survey revealed a population of 3,395 ± SE of 797 elephants, but populations had declined 21% from the 2005 estimate. The high number of carcasses observed on the survey suggests that populations may have increased after the 2005 survey but were declining rapidly as of 2015. Satellite-collared elephants avoided areas <6 km from human indicators but preferred areas nearer humans at scales of 6-40 km, suggesting that humans may be displacing elephants from preferred habitats near rivers. Taken together, these results suggest that Angola's elephant population is experiencing intense poaching and may be losing habitat to human settlements. Without action to conserve their populations, Angola's elephants face an uncertain future.

African American parents' attitudes toward HPV vaccination.

PubMed

Thompson, Vetta L Sanders; Arnold, Lauren D; Notaro, Sheri R

2011-01-01

This study sought to determine knowledge about human papillomaviruses (HPV), vaccination acceptability and intent to vaccinate, and describe the individual characteristics, and sociocultural attitudes that affect African American parents' intent to vaccinate their daughters. Two hundred African Americans completed self-administered surveys that assessed factors that may influence HPV vaccination behavior, HPV and cervical cancer knowledge and risk perception, cultural attitudes, and preferences for location and timing of vaccination. Eligibility criteria included men and women who had a daughter aged 9 to 17 years, whether the daughter had or had not been told that she had an HPV infection. Approximately two-thirds of the African American parents surveyed were aware of HPV and HPV vaccination. Responders were likely to be female, younger, employed, and to have social resources. They were also knowledgeable about HPV, but knowledge did not necessarily lead to vaccination. Among parents knowledgeable about HPV, vaccination status was significantly affected by whether a pediatrician had recommended the vaccine. There were no significant differences in demographic characteristics or sociocultural attitudes between the parents who had vaccinated their daughters and those who had not, although more of the parents who had vaccinated daughters were worried about STIs.

African Music in the Americas

ERIC Educational Resources Information Center

Goines, Leonard

1977-01-01

Discusses African music, how it survived slavery, why it manifests itself in specific forms, why some of these forms are almost purely African today while others are very European, the specific characteristics of African music that permeate all African-American music, and why African derived religions are flourishing in the black communities of…

Lineage-specific expansions of retroviral insertions within the genomes of African great apes but not humans and orangutans.

PubMed

Yohn, Chris T; Jiang, Zhaoshi; McGrath, Sean D; Hayden, Karen E; Khaitovich, Philipp; Johnson, Matthew E; Eichler, Marla Y; McPherson, John D; Zhao, Shaying; Pääbo, Svante; Eichler, Evan E

2005-04-01

Retroviral infections of the germline have the potential to episodically alter gene function and genome structure during the course of evolution. Horizontal transmissions between species have been proposed, but little evidence exists for such events in the human/great ape lineage of evolution. Based on analysis of finished BAC chimpanzee genome sequence, we characterize a retroviral element (Pan troglodytes endogenous retrovirus 1 [PTERV1]) that has become integrated in the germline of African great ape and Old World monkey species but is absent from humans and Asian ape genomes. We unambiguously map 287 retroviral integration sites and determine that approximately 95.8% of the insertions occur at non-orthologous regions between closely related species. Phylogenetic analysis of the endogenous retrovirus reveals that the gorilla and chimpanzee elements share a monophyletic origin with a subset of the Old World monkey retroviral elements, but that the average sequence divergence exceeds neutral expectation for a strictly nuclear inherited DNA molecule. Within the chimpanzee, there is a significant integration bias against genes, with only 14 of these insertions mapping within intronic regions. Six out of ten of these genes, for which there are expression data, show significant differences in transcript expression between human and chimpanzee. Our data are consistent with a retroviral infection that bombarded the genomes of chimpanzees and gorillas independently and concurrently, 3-4 million years ago. We speculate on the potential impact of such recent events on the evolution of humans and great apes.

The changing epidemiology of human African trypanosomiasis among patients from nonendemic countries--1902-2012.

PubMed

Neuberger, Ami; Meltzer, Eyal; Leshem, Eyal; Dickstein, Yaakov; Stienlauf, Shmuel; Schwartz, Eli

2014-01-01

Although human African trypanosomiasis (HAT) is uncommon among patients from non-endemic countries (NEC), there has been an increase in the number of cases reported in recent years. A systematic review of the literature was performed. The number of incoming tourists to HAT endemic countries was obtained from the United Nations World Tourism Organization. All HAT cases diagnosed in patients from NEC were included. Immigrants and refugees were excluded. We compared patients during and after the colonial period, and analyzed the relationship between the number of incoming travellers and the number of HAT cases. Between 1902 and 2012, HAT was reported in 244 patients. Most HAT cases were reported before 1920, and after the year 2000. In the colonial era the average age of patients was lower (32.5±7.8 vs. 43.0±16.1 years, P<0.001), the proportion of females was lower (10.0% vs. 23.9%, P<0.01], most cases were diagnosed in expatriates, missionaries and soldiers (74.3%), and Gambian trypanosomiasis accounted for 86/110, (78%) of cases. In the post-colonial era most patients 91/125 (72.8%) were short-term tourists to game parks in Eastern and South-Eastern Africa (mainly in Tanzania); Rhodesian trypanosomiasis accounted for 94/123 (76.4%) of cases. Between 1995 and 2010 there has been a constant linear increase in the number of incoming tourists to Tanzania, and HAT cases occurred in small outbreaks rather than following a similar linear pattern. In recent decades HAT patients from NEC are older, and more likely to be tourists who acquired the disease while visiting game-parks in Eastern and South-Eastern Africa. While Rhodesian trypanosomiasis is relatively uncommon among Africans, it now accounts for most cases reported among patients from NEC. Returning febrile travellers without an alternative diagnosis should be evaluated for HAT. Cases among travellers may serve as sentinels for Rhodesian trypanosomiasis "hot spots" in Africa.

76 FR 6519 - National African American History Month, 2011

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-04

... and women have persevered to enrich our national life and bend the arc of history toward justice. From... the domain of freedom. Beyond the battlefield, black men and women also supported the war effort by... the next century, the United States struggled to deliver fundamental civil and human rights to African...

Global diversity, population stratification, and selection of human copy number variation

PubMed Central

Sudmant, Peter H.; Mallick, Swapan; Nelson, Bradley J.; Hormozdiari, Fereydoun; Krumm, Niklas; Huddleston, John; Coe, Bradley P.; Baker, Carl; Nordenfelt, Susanne; Bamshad, Michael; Jorde, Lynn B.; Posukh, Olga L.; Sahakyan, Hovhannes; Watkins, W. Scott; Yepiskoposyan, Levon; Abdullah, M. Syafiq; Bravi, Claudio M.; Capelli, Cristian; Hervig, Tor; Wee, Joseph T. S.; Tyler-Smith, Chris; van Driem, George; Romero, Irene Gallego; Jha, Aashish R.; Karachanak-Yankova, Sena; Toncheva, Draga; Comas, David; Henn, Brenna; Kivisild, Toomas; Ruiz-Linares, Andres; Sajantila, Antti; Metspalu, Ene; Parik, Jüri; Villems, Richard; Starikovskaya, Elena B.; Ayodo, George; Beall, Cynthia M.; Di Rienzo, Anna; Hammer, Michael; Khusainova, Rita; Khusnutdinova, Elza; Klitz, William; Winkler, Cheryl; Labuda, Damian; Metspalu, Mait; Tishkoff, Sarah A.; Dryomov, Stanislav; Sukernik, Rem; Patterson, Nick; Reich, David; Eichler, Evan E.

2015-01-01

In order to explore the diversity and selective signatures of duplication and deletion human copy number variants (CNVs), we sequenced 236 individuals from 125 distinct human populations. We observed that duplications exhibit fundamentally different population genetic and selective signatures than deletions and are more likely to be stratified between human populations. Through reconstruction of the ancestral human genome, we identify megabases of DNA lost in different human lineages and pinpoint large duplications that introgressed from the extinct Denisova lineage now found at high frequency exclusively in Oceanic populations. We find that the proportion of CNV base pairs to single nucleotide variant base pairs is greater among non-Africans than it is among African populations, but we conclude that this difference is likely due to unique aspects of non-African population history as opposed to differences in CNV load. PMID:26249230

Evaluating Career Success of African American Males: It's What You Know and Who You Are that Matters

ERIC Educational Resources Information Center

Johnson, C. Douglas; Eby, Lillian T.

2011-01-01

The objectives of the present study were to identify the factors related to career success of college educated, African American men and to explore the relative importance of human capital, social capital, individual differences, and demographic attributes in predicting career success. Using a sample of 247 African American males, we found some…

Teaching How to Fish: Employment Skills for African American Women.

ERIC Educational Resources Information Center

Smith, Zira J.

1996-01-01

Agrees with Jeremy Rifkin that "human labor is being systematically eliminated from the economic process" and deplores educators' slowness to recognize implications. Since individuals must create their own work, educational programs should stress entrepreneurship and self-employment skills, not job-seeking behaviors. African American…

Obesity and African Americans

MedlinePlus

... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... youthonline . [Accessed 08/18/2017] HEALTH IMPACT OF OBESITY People who are overweight are more likely to ...

Pedagogy of the Dispersed: A Cost-Benefit Analysis of the African Diaspora Phenomenon through the Human and Social Capital Lens

ERIC Educational Resources Information Center

Kivunja, Charles; Shizha, Edward

2015-01-01

With its origin in Greek where "diaspora" as a noun means "a dispersion" or as a verb means to "scatter about", the term is used in this paper to refer to the dispersion or scattering of Africans from their original African homeland and now live in countries other than their own. Indeed some Africans have dispersed…

A SNP test to identify Africanized honeybees via proportion of 'African' ancestry.

PubMed

Chapman, Nadine C; Harpur, Brock A; Lim, Julianne; Rinderer, Thomas E; Allsopp, Michael H; Zayed, Amro; Oldroyd, Benjamin P

2015-11-01

The honeybee, Apis mellifera, is the world's most important pollinator and is ubiquitous in most agricultural ecosystems. Four major evolutionary lineages and at least 24 subspecies are recognized. Commercial populations are mainly derived from subspecies originating in Europe (75-95%). The Africanized honeybee is a New World hybrid of A. m. scutellata from Africa and European subspecies, with the African component making up 50-90% of the genome. Africanized honeybees are considered undesirable for bee-keeping in most countries, due to their extreme defensiveness and poor honey production. The international trade in honeybees is restricted, due in part to bans on the importation of queens (and semen) from countries where Africanized honeybees are extant. Some desirable strains from the United States of America that have been bred for traits such as resistance to the mite Varroa destructor are unfortunately excluded from export to countries such as Australia due to the presence of Africanized honeybees in the USA. This study shows that a panel of 95 single nucleotide polymorphisms, chosen to differentiate between the African, Eastern European and Western European lineages, can detect Africanized honeybees with a high degree of confidence via ancestry assignment. Our panel therefore offers a valuable tool to mitigate the risks of spreading Africanized honeybees across the globe and may enable the resumption of queen and bee semen imports from the Americas. © 2015 John Wiley & Sons Ltd.

Exploring Self-Efficacy and Locus of Control as Risk Factors in Sexual Decision Making for African American Women

ERIC Educational Resources Information Center

Pimpleton, Asher M.

2012-01-01

Sexually transmitted diseases have reached epidemic proportions, especially among African Americans. However, African American women have emerged as being one of the hardest hit groups by the most fatal of sexually transmitted diseases--the Human Immunodeficiency Virus (HIV) and the Acquired Immune Deficiency Syndrome (AIDS). Although there has…

Addressing social responsibility in medical education: the African way.

PubMed

Kwizera, Enoch N; Iputo, Jehu E

2011-01-01

Indigenous sub-Saharan societies have, over the millennia, lived and socialised within the unwritten 'rules' of the 'Ubuntu' or similar philosophies that emphasises holistic 'humanness', and which is a form of 'social responsibility'. This article looks into some relevant social responsibility aspects of medical education in the South African context, with particular emphasis on how these aspects have been addressed. Apartheid was, by its very nature, incompatible with social responsibility for the majority of South Africans, but one medical school that was a non-complicit product of apartheid succeeded in fulfilling a socially responsible mission. Thus, this article implicitly identifies what South Africa, Africa and the global Health Professions Education community could learn from these trail-blazing experiences.

Development and Implementation of an AIDS Prevention Program for African-American Women at a Child Care Center.

ERIC Educational Resources Information Center

Moten-Tolson, Paula

This program was designed to provide Acquired Immune Deficiency Syndrome (AIDS) prevention education for African-American women of child bearing age at a child care center which serves low income high risk families. The primary goal was to reduce the risk of African-American women at the child care center for contracting the Human Immunodeficiency…

Shorter telomere length in Europeans than in Africans due to polygenetic adaptation.

PubMed

Hansen, Matthew E B; Hunt, Steven C; Stone, Rivka C; Horvath, Kent; Herbig, Utz; Ranciaro, Alessia; Hirbo, Jibril; Beggs, William; Reiner, Alexander P; Wilson, James G; Kimura, Masayuki; De Vivo, Immaculata; Chen, Maxine M; Kark, Jeremy D; Levy, Daniel; Nyambo, Thomas; Tishkoff, Sarah A; Aviv, Abraham

2016-06-01

Leukocyte telomere length (LTL), which reflects telomere length in other somatic tissues, is a complex genetic trait. Eleven SNPs have been shown in genome-wide association studies to be associated with LTL at a genome-wide level of significance within cohorts of European ancestry. It has been observed that LTL is longer in African Americans than in Europeans. The underlying reason for this difference is unknown. Here we show that LTL is significantly longer in sub-Saharan Africans than in both Europeans and African Americans. Based on the 11 LTL-associated alleles and genetic data in phase 3 of the 1000 Genomes Project, we show that the shifts in allele frequency within Europe and between Europe and Africa do not fit the pattern expected by neutral genetic drift. Our findings suggest that differences in LTL within Europeans and between Europeans and Africans is influenced by polygenic adaptation and that differences in LTL between Europeans and Africans might explain, in part, ethnic differences in risks for human diseases that have been linked to LTL. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

African palm ethno-medicine.

PubMed

Gruca, Marta; Blach-Overgaard, Anne; Balslev, Henrik

2015-05-13

This study is the first to demonstrate the breadth and patterns of the medicinal applications of African palms. It sheds light on species with the potential to provide new therapeutic agents for use in biomedicine; and links the gap between traditional use of palms and pharmacological evaluation for the beneficial effects of palm products on human health. Last but not least, the study provides recommendations for the areas that should be targeted in future ethno-botanical surveys. The primary objective of this survey was to assemble all available ethno-medicinal data on African palms, and investigate patterns of palm uses in traditional medicine; and highlight possible under-investigated areas. References were found through bibliographic searches using several sources including PubMed, Embase, and Google Scholar and search engines of the State and University Libraries of Aarhus, National Library of Denmark and Copenhagen University Libraries, Harvard University Libraries, and the Mertz Library. Information about ethno-medicinal uses of palms was extracted and digitized in a database. Additionally, we used an African palm distribution database to compute the proportion of palm species that have been used for medicinal purposes in each country. We found 782 medicinal uses mentioned in 156 references. At least 23 different palm species (some remained unidentified) were used medicinally in 35 out of Africa's 48 countries. The most commonly used species were Elaeis guineensis, Phoenix dactylifera, Cocos nucifera, and Borassus aethiopum. Medicinal uses were in 25 different use categories of which the most common ones were Infections/Infestations and Digestive System Disorders. Twenty-four different parts of the palms were used in traditional medicine, with most of the uses related to fruit (and palm oil), root, seed and leaf. Palms were used in traditional medicine mostly without being mixed with other plants, and less commonly in mixtures, sometimes in mixture with

Drivers of extinction risk in African mammals: the interplay of distribution state, human pressure, conservation response and species biology

PubMed Central

Di Marco, Moreno; Buchanan, Graeme M.; Szantoi, Zoltan; Holmgren, Milena; Grottolo Marasini, Gabriele; Gross, Dorit; Tranquilli, Sandra; Boitani, Luigi; Rondinini, Carlo

2014-01-01

Although conservation intervention has reversed the decline of some species, our success is outweighed by a much larger number of species moving towards extinction. Extinction risk modelling can identify correlates of risk and species not yet recognized to be threatened. Here, we use machine learning models to identify correlates of extinction risk in African terrestrial mammals using a set of variables belonging to four classes: species distribution state, human pressures, conservation response and species biology. We derived information on distribution state and human pressure from satellite-borne imagery. Variables in all four classes were identified as important predictors of extinction risk, and interactions were observed among variables in different classes (e.g. level of protection, human threats, species distribution ranges). Species biology had a key role in mediating the effect of external variables. The model was 90% accurate in classifying extinction risk status of species, but in a few cases the observed and modelled extinction risk mismatched. Species in this condition might suffer from an incorrect classification of extinction risk (hence require reassessment). An increased availability of satellite imagery combined with improved resolution and classification accuracy of the resulting maps will play a progressively greater role in conservation monitoring. PMID:24733953

An African Perspective on Peace Education: Ubuntu Lessons in Reconciliation

NASA Astrophysics Data System (ADS)

Murithi, Tim

2009-05-01

This essay examines the value of educating for peace. It does this through a consideration of the African cultural world-view known as ubuntu, which highlights the essential unity of humanity and emphasises the importance of constantly referring to the principles of empathy, sharing and cooperation in efforts to resolve our common problems. The essay is not based on field research, but rather on a discussion of the issues pertaining to ubuntu and peace education. The discussion focuses on how Desmond Tutu utilised the principles of ubuntu during his leadership of the South African Truth and Reconciliation Commission. It also outlines the five stages of the peacemaking process found among ubuntu societies: acknowledging guilt; showing remorse and repenting; asking for and giving forgiveness; and paying compensation or reparations as a prelude to reconciliation. Potential lessons for educating for peace and reconciliation are highlighted based on the premise that the ubuntu approach to human relationship-building can offer an example to the world.

The Dust at Altitude Recovery Technology (DART) System was Developed to Recover Plant, Human, and Animal Pathogens in Asian and African Dust Storms over North America

NASA Astrophysics Data System (ADS)

Schuerger, A. C.; Tench, B.; Nehr, A.; Emmons, T.; Valbuena, F.; Palaia, J.; Sugars, C.

2014-12-01

Dust emanates year-round from Africa and Asia and impacts air quality in North America. Asian dust plumes deliver up to 64 million tonnes of dust over the NW of the USA, and African dust storms deliver over 50 million tonnes of dust over Florida each year. Several recent studies have demonstrated that human and plant pathogens from Asian [1] African [2] aerosols can be transported to N. America in naturally occurring dust storms. What is unknown is whether these 'presumptive pathogens' impact human, plant, or animal health in the USA. In order to initiate a long-term monitoring program of pathogens in Asian and African dust plumes, we have developed a dust collection system called DART (Dust at Altitude Recovery Technology) (figure). The DART dust sampler can be mounted on a F104 Starfighter jet (figure) and a T6 Texan propeller driven airplane (not shown), and was test flown over FL in Dec. 2013 on the F104 and on the T6 in the summer of 2014. The DART system utilizes a high-volume pump to pass air through 6 separate filtration units where both aerosols and microbial cells are captured. The filtration systems exhibit flow rates from 25-142 L/min depending on the pore size and brand of filters used. Flow rates are directly correlated to increased air speed, and are inversely correlated to increased altitude. Filtration units can be turned on and off individually as required for specific science flight objectives. The DART dust sampler has performed nominally up to 7600 m, 0.92 Mach, and 3.5 +G's. During initial test flights in Dec. 2013, 5 of 8 genera of fungi recovered from the lower atmosphere over FL contained plant pathogens including species in the genera: Acremonium, Aspergillus, Cladosporium, Curvularia, and Fusarium. Numbers of recovered fungi, but not bacteria, increased significantly when 5 or 10 µm filters were used in the DART system compared to filter pore sizes ≤ 1.2 µm. Future sampling programs for both Asian and African dust events will be

Development and Use of a Serum Bactericidal Assay Using Pooled Human Complement To Assess Responses to a Meningococcal Group A Conjugate Vaccine in African Toddlers

PubMed Central

Lynn, Freyja; Mocca, Brian; Borrow, Ray; Findlow, Helen; Hassan-King, Musa; Preziosi, Marie-Pierre; Idoko, Olubukola; Sow, Samba; Kulkarni, Prasad; LaForce, F. Marc

2014-01-01

A meningococcal group A polysaccharide (PS) conjugate vaccine (PsA-TT) has been developed for African countries affected by epidemic meningitis caused by Neisseria meningitidis. Complement-mediated serum bactericidal antibody (SBA) assays are used to assess protective immune responses to meningococcal vaccination. Human complement (hC′) was used in early studies demonstrating antibody-mediated protection against disease, but it is difficult to obtain and standardize. We developed and evaluated a method for sourcing hC′ and then used the SBA assay with hC′ (hSBA) to measure bactericidal responses to PsA-TT vaccination in 12- to 23-month-old African children. Sera with active complement from 100 unvaccinated blood donors were tested for intrinsic bactericidal activity, SBA titer using rabbit complement (rSBA), and anti-group A PS antibody concentration. Performance criteria and pooling strategies were examined and then verified by comparisons of three independently prepared hC′ lots in two laboratories. hSBA titers of clinical trial sera were then determined using this complement sourcing method. Two different functional antibody tests were necessary for screening hC′. hSBA titers determined using three independent lots of pooled hC′ were within expected assay variation among lots and between laboratories. In African toddlers, PsA-TT elicited higher hSBA titers than meningococcal polysaccharide or Hib vaccines. PsA-TT immunization or PS challenge of PsA-TT-primed subjects resulted in vigorous hSBA memory responses, and titers persisted in boosted groups for over a year. Quantifying SBA using pooled hC′ is feasible and showed that PsA-TT was highly immunogenic in African toddlers. PMID:24671551

FTO Genetic Variation and Association With Obesity in West Africans and African Americans

PubMed Central

Adeyemo, Adebowale; Chen, Guanjie; Zhou, Jie; Shriner, Daniel; Doumatey, Ayo; Huang, Hanxia; Rotimi, Charles

2010-01-01

OBJECTIVE The FTO gene is one of the most consistently replicated loci for obesity. However, data from populations of African ancestry are limited. We evaluated genetic variation in the FTO gene and investigated associations with obesity in West Africans and African Americans. RESEARCH DESIGN AND METHODS The study samples comprised 968 African Americans (59% female, mean age 49 years, mean BMI 30.8 kg/m2) and 517 West Africans (58% female, mean age 54 years, mean BMI 25.5 kg/m2). FTO genetic variation was evaluated by genotyping 262 tag single nucleotide polymorphisms (SNPs) across the entire gene. Association of each SNP with BMI, waist circumference, and percent fat mass was investigated under an additive model. RESULTS As expected, both African-ancestry samples showed weaker linkage disequilibrium (LD) patterns compared with other continental (e.g., European) populations. Several intron 8 SNPs, in addition to intron 1 SNPs, showed significant associations in both study samples. The combined effect size for BMI for the top SNPs from meta-analysis was 0.77 kg/m2 (P = 0.009, rs9932411) and 0.70 kg/m2 (P = 0.006, rs7191513). Two previously reported associations with intron 1 SNPs (rs1121980 and rs7204609, r2 = 0.001) were replicated among the West Africans. CONCLUSIONS The FTO gene shows significant differences in allele frequency and LD patterns in populations of African ancestry compared with other continental populations. Despite these differences, we observed evidence of associations with obesity in African Americans and West Africans, as well as evidence of heterogeneity in association. More studies of FTO in multiple ethnic groups are needed. PMID:20299471

Corporal Punishment in Schools and Fundamental Human Rights: A South African Perspective.

ERIC Educational Resources Information Center

Prinsloo, Justus

In many western countries, corporal punishment has been abolished as a form of punishment in criminal trials and in schools. Under South African common law, persons entitled to enforce discipline may inflict corporal punishment within certain guidelines established by the Supreme Court. For the first time in the Republic of South Africa (RSA), the…

Surveillance of Canine Rabies in the Central African Republic: Impact on Human Health and Molecular Epidemiology.

PubMed

Tricou, Vianney; Bouscaillou, Julie; Kamba Mebourou, Emmanuel; Koyanongo, Fidèle Dieudonné; Nakouné, Emmanuel; Kazanji, Mirdad

2016-02-01

Although rabies represents an important public health threat, it is still a neglected disease in Asia and Africa where it causes tens of thousands of deaths annually despite available human and animal vaccines. In the Central African Republic (CAR), an endemic country for rabies, this disease remains poorly investigated. To evaluate the extent of the threat that rabies poses in the CAR, we analyzed data for 2012 from the National Reference Laboratory for Rabies, where laboratory confirmation was performed by immunofluorescence and PCR for both animal and human suspected cases, and data from the only anti-rabies dispensary of the country and only place where post-exposure prophylaxis (PEP) is available. Both are located in Bangui, the capital of the CAR. For positive samples, a portion of the N gene was amplified and sequenced to determine the molecular epidemiology of circulating strains. In 2012, 966 exposed persons visited the anti-rabies dispensary and 632 received a post-exposure rabies vaccination. More than 90% of the exposed persons were from Bangui and its suburbs and almost 60% of them were under 15-years of age. No rabies-related human death was confirmed. Of the 82 samples from suspected rabid dogs tested, 69 were confirmed positive. Most of the rabid dogs were owned although unvaccinated. There was a strong spatiotemporal correlation within Bangui and within the country between reported human exposures and detection of rabid dogs (P<0.001). Phylogenetic analysis indicated that three variants belonging to Africa I and II lineages actively circulated in 2012. These data indicate that canine rabies was endemic in the CAR in 2012 and had a detrimental impact on human health as shown by the hundreds of exposed persons who received PEP. Implementation of effective public health interventions including mass dog vaccination and improvement of the surveillance and the access to PEP are urgently needed in this country.

Surveillance of Canine Rabies in the Central African Republic: Impact on Human Health and Molecular Epidemiology

PubMed Central

Tricou, Vianney; Bouscaillou, Julie; Kamba Mebourou, Emmanuel; Koyanongo, Fidèle Dieudonné; Nakouné, Emmanuel; Kazanji, Mirdad

2016-01-01

Background Although rabies represents an important public health threat, it is still a neglected disease in Asia and Africa where it causes tens of thousands of deaths annually despite available human and animal vaccines. In the Central African Republic (CAR), an endemic country for rabies, this disease remains poorly investigated. Methods To evaluate the extent of the threat that rabies poses in the CAR, we analyzed data for 2012 from the National Reference Laboratory for Rabies, where laboratory confirmation was performed by immunofluorescence and PCR for both animal and human suspected cases, and data from the only anti-rabies dispensary of the country and only place where post-exposure prophylaxis (PEP) is available. Both are located in Bangui, the capital of the CAR. For positive samples, a portion of the N gene was amplified and sequenced to determine the molecular epidemiology of circulating strains. Results In 2012, 966 exposed persons visited the anti-rabies dispensary and 632 received a post-exposure rabies vaccination. More than 90% of the exposed persons were from Bangui and its suburbs and almost 60% of them were under 15-years of age. No rabies-related human death was confirmed. Of the 82 samples from suspected rabid dogs tested, 69 were confirmed positive. Most of the rabid dogs were owned although unvaccinated. There was a strong spatiotemporal correlation within Bangui and within the country between reported human exposures and detection of rabid dogs (P<0.001). Phylogenetic analysis indicated that three variants belonging to Africa I and II lineages actively circulated in 2012. Conclusions These data indicate that canine rabies was endemic in the CAR in 2012 and had a detrimental impact on human health as shown by the hundreds of exposed persons who received PEP. Implementation of effective public health interventions including mass dog vaccination and improvement of the surveillance and the access to PEP are urgently needed in this country. PMID

New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens.

PubMed

Hublin, Jean-Jacques; Ben-Ncer, Abdelouahed; Bailey, Shara E; Freidline, Sarah E; Neubauer, Simon; Skinner, Matthew M; Bergmann, Inga; Le Cabec, Adeline; Benazzi, Stefano; Harvati, Katerina; Gunz, Philipp

2017-06-07

Fossil evidence points to an African origin of Homo sapiens from a group called either H. heidelbergensis or H. rhodesiensis. However, the exact place and time of emergence of H. sapiens remain obscure because the fossil record is scarce and the chronological age of many key specimens remains uncertain. In particular, it is unclear whether the present day 'modern' morphology rapidly emerged approximately 200 thousand years ago (ka) among earlier representatives of H. sapiens or evolved gradually over the last 400 thousand years. Here we report newly discovered human fossils from Jebel Irhoud, Morocco, and interpret the affinities of the hominins from this site with other archaic and recent human groups. We identified a mosaic of features including facial, mandibular and dental morphology that aligns the Jebel Irhoud material with early or recent anatomically modern humans and more primitive neurocranial and endocranial morphology. In combination with an age of 315 ± 34 thousand years (as determined by thermoluminescence dating), this evidence makes Jebel Irhoud the oldest and richest African Middle Stone Age hominin site that documents early stages of the H. sapiens clade in which key features of modern morphology were established. Furthermore, it shows that the evolutionary processes behind the emergence of H. sapiens involved the whole African continent.

Recruiting intergenerational African American males for biomedical research Studies: a major research challenge.

PubMed

Byrd, Goldie S; Edwards, Christopher L; Kelkar, Vinaya A; Phillips, Ruth G; Byrd, Jennifer R; Pim-Pong, Dora Som; Starks, Takiyah D; Taylor, Ashleigh L; Mckinley, Raechel E; Li, Yi-Ju; Pericak-Vance, Margaret

2011-06-01

The health and well-being of all individuals, independent of race, ethnicity, or gender, is a significant public health concern. Despite many improvements in the status of minority health, African American males continue to have the highest age-adjusted mortality rate of any race-sex group in the United States. Such disparities are accounted for by deaths from a number of diseases such as diabetes, human immunodeficiency virus (HIV), cancer, and cardiovascular disease, as well as by many historical and present social and cultural constructs that present as obstacles to better health outcomes. Distrust of the medical community, inadequate education, low socioeconomic status, social deprivation, and underutilized primary health care services all contribute to disproportionate health and health care outcomes among African Americans compared to their Caucasian counterparts. Results of clinical research on diseases that disproportionately affect African American males are often limited in their reliability due to common sampling errors existing in the majority of biomedical research studies and clinical trials. There are many reasons for underrepresentation of African American males in clinical trials, including their common recollection and interpretation of relevant historical of biomedical events where minorities were abused or exposed to racial discrimination or racist provocation. In addition, African American males continue to be less educated and more disenfranchised from the majority in society than Caucasian males and females and their African American female counterparts. As such, understanding their perceptions, even in early developmental years, about health and obstacles to involvement in research is important. In an effort to understand perspectives about their level of participation, motivation for participation, impact of education, and engagement in research, this study was designed to explore factors that impact their willingness to participate. Our

Emerging landscape degradation trends in the East African Horn

NASA Astrophysics Data System (ADS)

Pricope, N. G.; Michaelsen, J.; Husak, G. J.; Funk, C. C.; Lopez-Carr, D.

2012-12-01

Increasing climate variability along with declining trends in rainfall represent major risk factors affecting food security in many regions of the world. We identify Africa-wide regions where significant rainfall decreases from 1979-2011 are coupled with significant human population density increases. The rangelands of the East African Horn remain one of the world's most food insecure regions with significantly increasing human populations predominantly dependent on pastoralist and agro-pastoralist livelihoods. Widespread vegetation degradation is occurring, adversely impacting fragile ecosystems and human livelihoods. Using MODIS land cover and normalized difference vegetation index (NDVI) data collected since 2000, we observe significant changes in vegetation patterns and productivity over the last decade across the East African Horn and demonstrate that these two products can be used concurrently at large spatial scales to monitor vegetation dynamics at decadal time scales. Results demonstrate that a near doubling of the population in pastoral regions is linked with hotspots of degradation in vegetation condition. The most significant land cover change and browning trends are observed in areas experiencing drying precipitation trends in addition to increasing population pressures. These findings have serious implications for current and future regional food security monitoring and forecasting and for mitigation and adaptation strategies in a region where population is expected to continue increasing against a backdrop of drying climate trends.Fig.1(a)Change in standardized precipitation index in Africa between 1979-2010 (b)Change in population density at continental scale using the GRUMPv1 1990 and 2000 and AfriPop 2010 population density datasets Fig.2 Land cover change trajectories based on 2001-2009 MOD12Q1 Land Cover product for the East African Horn overlaid over aggregated FEWS Net Livelihoods Zones.

Research Perspectives on African Education and the Informal Sector.

ERIC Educational Resources Information Center

Honig, Benson

This paper is concerned with the human capital theory of education as it is employed in designing, justifying, and funding African educational programs. According to this theory, where the most measurable and direct relationships between the world of work and that of school are purported to exist, those individuals who invest in education are…

Poaching and human encroachment reverse recovery of African savannah elephants in south-east Angola despite 14 years of peace

PubMed Central

Chase, Michael J.; Griffin, Curtice R.

2018-01-01

With populations of African savannah elephants (Loxodonta africana) declining across the continent, assessing the status of individual elephant populations is important for conservation. Angola’s elephant population represents a key linkage between the larger populations of Namibia and Botswana. Elephants in Angola were decimated during the 1975–2002 Angolan civil war, but a 2005 survey showed that populations were recolonizing former habitats. Between 2005 and 2015, no research was permitted on elephants in Angola, but elsewhere in Africa many elephant populations experienced a poaching crisis. In 2015, we were able to resume elephant research in Angola. We used aerial surveys and satellite monitoring of collared elephants to determine the current status of elephant populations in Angola and to learn how human populations may be affecting elephant habitat usage. The aerial survey revealed a population of 3,395 ± SE of 797 elephants, but populations had declined 21% from the 2005 estimate. The high number of carcasses observed on the survey suggests that populations may have increased after the 2005 survey but were declining rapidly as of 2015. Satellite-collared elephants avoided areas <6 km from human indicators but preferred areas nearer humans at scales of 6–40 km, suggesting that humans may be displacing elephants from preferred habitats near rivers. Taken together, these results suggest that Angola’s elephant population is experiencing intense poaching and may be losing habitat to human settlements. Without action to conserve their populations, Angola’s elephants face an uncertain future. PMID:29538387

Comprehensive Molecular Profiling of African-American Prostate Cancer to Inform on Prognosis and Disease Biology

DTIC Science & Technology

2017-10-01

development and patterning, and to become more knowledgeable in molecular genetics and the pathology of human prostatic diseases. Specific Aims: 1...AWARD NUMBER: W81XWH-15-1-0661 TITLE: Comprehensive Molecular Profiling of African-American Prostate Cancer to Inform on Prognosis and...COVERED 30 Sept 2016 – 29 Sept 2017 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Comprehensive Molecular Profiling of African-American Prostate Cancer to

The African Genome Variation Project shapes medical genetics in Africa

PubMed Central

Gurdasani, Deepti; Carstensen, Tommy; Tekola-Ayele, Fasil; Pagani, Luca; Tachmazidou, Ioanna; Hatzikotoulas, Konstantinos; Karthikeyan, Savita; Iles, Louise; Pollard, Martin O.; Choudhury, Ananyo; Ritchie, Graham R. S.; Xue, Yali; Asimit, Jennifer; Nsubuga, Rebecca N.; Young, Elizabeth H.; Pomilla, Cristina; Kivinen, Katja; Rockett, Kirk; Kamali, Anatoli; Doumatey, Ayo P.; Asiki, Gershim; Seeley, Janet; Sisay-Joof, Fatoumatta; Jallow, Muminatou; Tollman, Stephen; Mekonnen, Ephrem; Ekong, Rosemary; Oljira, Tamiru; Bradman, Neil; Bojang, Kalifa; Ramsay, Michele; Adeyemo, Adebowale; Bekele, Endashaw; Motala, Ayesha; Norris, Shane A.; Pirie, Fraser; Kaleebu, Pontiano; Kwiatkowski, Dominic; Tyler-Smith, Chris; Rotimi, Charles; Zeggini, Eleftheria; Sandhu, Manjinder S.

2014-01-01

Given the importance of Africa to studies of human origins and disease susceptibility, detailed characterisation of African genetic diversity is needed. The African Genome Variation Project (AGVP) provides a resource to help design, implement and interpret genomic studies in sub-Saharan Africa (SSA) and worldwide. The AGVP represents dense genotypes from 1,481 and whole genome sequences (WGS) from 320 individuals across SSA. Using this resource, we find novel evidence of complex, regionally distinct hunter-gatherer and Eurasian admixture across SSA. We identify new loci under selection, including for malaria and hypertension. We show that modern imputation panels can identify association signals at highly differentiated loci across populations in SSA. Using WGS, we show further improvement in imputation accuracy supporting efforts for large-scale sequencing of diverse African haplotypes. Finally, we present an efficient genotype array design capturing common genetic variation in Africa, showing for the first time that such designs are feasible. PMID:25470054

Clinical chemistry and hematology values in a Caribbean population of African green monkeys.

PubMed

Liddie, Shervin; Goody, Robin J; Valles, Rodrigo; Lawrence, Matthew S

2010-12-01

Hematology and clinical chemistry (HCC) reference values are critical in veterinary practice and in vivo pre-clinical research, enabling detection of health abnormalities, response to therapeutic intervention or adverse toxicological effects, as well as monitoring of clinical management. In this report, reference ranges for 46 HCC parameters were characterized in 331 wild-caught and colony-bred African green monkeys. Effects of sex, weight and duration of captivity were determined by one-way analysis of variance. Significant sex differences were observed for several HCC parameters. Significant differences were also observed for select HCC variables between newly caught animals and those held in captivity for 1-12 months or longer. Comparison of this data with other non-human primate species and humans highlights similarities and disparities between species. Potential causes of interpopulation variability and relevance to the use of the African green monkey as a non-human primate model are discussed. © 2010 John Wiley & Sons A/S.

Genome-wide Ancestry and Demographic History of African-Descendant Maroon Communities from French Guiana and Suriname.

PubMed

Fortes-Lima, Cesar; Gessain, Antoine; Ruiz-Linares, Andres; Bortolini, Maria-Cátira; Migot-Nabias, Florence; Bellis, Gil; Moreno-Mayar, J Víctor; Restrepo, Berta Nelly; Rojas, Winston; Avendaño-Tamayo, Efren; Bedoya, Gabriel; Orlando, Ludovic; Salas, Antonio; Helgason, Agnar; Gilbert, M Thomas P; Sikora, Martin; Schroeder, Hannes; Dugoujon, Jean-Michel

2017-11-02

The transatlantic slave trade was the largest forced migration in world history. However, the origins of the enslaved Africans and their admixture dynamics remain unclear. To investigate the demographic history of African-descendant Marron populations, we generated genome-wide data (4.3 million markers) from 107 individuals from three African-descendant populations in South America, as well as 124 individuals from six west African populations. Throughout the Americas, thousands of enslaved Africans managed to escape captivity and establish lasting communities, such as the Noir Marron. We find that this population has the highest proportion of African ancestry (∼98%) of any African-descendant population analyzed to date, presumably because of centuries of genetic isolation. By contrast, African-descendant populations in Brazil and Colombia harbor substantially more European and Native American ancestry as a result of their complex admixture histories. Using ancestry tract-length analysis, we detect different dates for the European admixture events in the African-Colombian (1749 CE; confidence interval [CI]: 1737-1764) and African-Brazilian (1796 CE; CI: 1789-1804) populations in our dataset, consistent with the historically attested earlier influx of Africans into Colombia. Furthermore, we find evidence for sex-specific admixture patterns, resulting from predominantly European paternal gene flow. Finally, we detect strong genetic links between the African-descendant populations and specific source populations in Africa on the basis of haplotype sharing patterns. Although the Noir Marron and African-Colombians show stronger affinities with African populations from the Bight of Benin and the Gold Coast, the African-Brazilian population from Rio de Janeiro has greater genetic affinity with Bantu-speaking populations from the Bight of Biafra and west central Africa. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Positioning women's and children's health in African union policy-making: a policy analysis

PubMed Central

2012-01-01

Background With limited time to achieve the Millennium Development Goals, progress towards improving women's and children's health needs to be accelerated. With Africa accounting for over half of the world's maternal and child deaths, the African Union (AU) has a critical role in prioritizing related policies and catalysing required investments and action. In this paper, the authors assess the evolution of African Union policies related to women's and children's health, and analyze how these policies are prioritized and framed. Methods The main method used in this policy analysis was a document review of all African Union policies developed from 1963 to 2010, focusing specifically on policies that explicitly mention health. The findings from this document review were discussed with key actors to identify policy implications. Results With over 220 policies in total, peace and security is the most common AU policy topic. Social affairs and other development issues became more prominent in the 1990s. The number of policies that mentioned health rose steadily over the years (with 1 policy mentioning health in 1963 to 7 in 2010). This change was catalysed by factors such as: a favourable shift in AU priorities and systems towards development issues, spurred by the transition from the Organization of African Unity to the African Union; the mandate of the African Commission on Human and People's Rights; health-related advocacy initiatives, such as the Campaign for the Accelerated Reduction of Maternal Mortality in Africa (CARMMA); action and accountability requirements arising from international human rights treaties, the Millennium Development Goals (MDGs), and new health-funding mechanisms, such as the Global Fund to Fight AIDS, Tuberculosis and Malaria. Prioritization of women's and children's health issues in AU policies has been framed primarily by human rights, advocacy and accountability considerations, more by economic and health frames looking at investments and

Positioning women's and children's health in African union policy-making: a policy analysis.

PubMed

Toure, Kadidiatou; Sankore, Rotimi; Kuruvilla, Shyama; Scolaro, Elisa; Bustreo, Flavia; Osotimehin, Babatunde

2012-02-16

With limited time to achieve the Millennium Development Goals, progress towards improving women's and children's health needs to be accelerated. With Africa accounting for over half of the world's maternal and child deaths, the African Union (AU) has a critical role in prioritizing related policies and catalysing required investments and action. In this paper, the authors assess the evolution of African Union policies related to women's and children's health, and analyze how these policies are prioritized and framed. The main method used in this policy analysis was a document review of all African Union policies developed from 1963 to 2010, focusing specifically on policies that explicitly mention health. The findings from this document review were discussed with key actors to identify policy implications. With over 220 policies in total, peace and security is the most common AU policy topic. Social affairs and other development issues became more prominent in the 1990s. The number of policies that mentioned health rose steadily over the years (with 1 policy mentioning health in 1963 to 7 in 2010).This change was catalysed by factors such as: a favourable shift in AU priorities and systems towards development issues, spurred by the transition from the Organization of African Unity to the African Union; the mandate of the African Commission on Human and People's Rights; health-related advocacy initiatives, such as the Campaign for the Accelerated Reduction of Maternal Mortality in Africa (CARMMA); action and accountability requirements arising from international human rights treaties, the Millennium Development Goals (MDGs), and new health-funding mechanisms, such as the Global Fund to Fight AIDS, Tuberculosis and Malaria.Prioritization of women's and children's health issues in AU policies has been framed primarily by human rights, advocacy and accountability considerations, more by economic and health frames looking at investments and impact. AU policies related

Tsetse ecology in a Liberian rain-forest focus of Gambian sleeping sickness.

PubMed

Kaminsky, R

1987-07-01

Investigations on tsetse ecology were undertaken in Bong County of Liberia during the dry season, October 1981 to February 1982, around villages where the human infection rate with Trypanosoma brucei gambiense Dutton was about 2%. Most tsetse captured in biconical traps were Glossina palpalis Robineau-Desvoidy and G. pallicera Bigot, with relatively few G. fusca Walker and G. nigrofusca Newstead. Swamps and water-gathering places were predominant habitats of all four species, but tsetse were also found in coffee and cocoa plantations. Breeding-places of G. palpalis were found in the leaf axils of oilpalm trees (Elaeis guineensis Jacquin), especially beside paths where people would risk being bitten. Bloodmeals of twenty-nine wild-caught G. palpalis were identified as mostly from man (fifteen) and bushbuck (Tragelaphus scriptus (Pallas] or other wild ruminants (eleven), plus three from reptiles. It is concluded that man may be the principal host of tsetse in the area, while man or bushbuck could be the main reservoir to T.b. gambiense infection. Most of the activity of G. palpalis occurs in the early afternoon from noon to 16.00 hours. Mean life-span of G. palpalis and G. pallicera, estimated from wing-fray age-groups, was consistent with the females, and to a lesser degree the males, having vector potential.

Differences between African-American adolescent females with and without human papillomavirus infection.

PubMed

Seth, Puja; Wingood, Gina M; Diclemente, Ralph J; Crosby, Richard A; Salazar, Laura F; Rose, Eve S; Sales, Jessica M

2011-03-01

An important policy question is whether high-risk populations can be identified and prioritised for human papillomavirus (HPV) immunisation. Data collection included an audio computer-assisted survey interview and testing of Trichomonas vaginalis, Chlamydia trachomatis, Neisseria gonorrhoeae, and HPV among 295 African-American adolescent females. The results indicated that 43.1% tested positive for HPV. Logistic regression analyses indicated that HPV prevalence was not associated with other sexually transmissible infections (prevalence ratio (PR)=0.85, 95% confidence interval (CI)=0.51-1.41), unprotected vaginal sex (PR=1.04, 95% CI=0.56-1.92), having sex with an older male partner (PR=1.12, 95% CI=0.64-1.96), and having a casual partner (PR=0.89, 95% CI=0.54-1.48). Additionally, t-tests indicated that HPV prevalence was not associated with frequency of vaginal sex (t=0.17, P=0.87), protected sex (t=-0.16, P=0.87), number of recent (t=0.40, P=0.69) or lifetime (t=1.45, P=0.15) sexual partners. However, those testing positive for HPV were younger (t=1.97, P=0.05) and reported current use of birth control pills (PR=2.38, 95% CI=1.00-5.63). It may not be possible to identify those with elevated risk of HPV acquisition. Thus, HPV vaccination, regardless of risk indicators, may be the most efficacious public health strategy.

Further morphological evidence on South African earliest Homo lower postcanine dentition: Enamel thickness and enamel dentine junction.

PubMed

Pan, Lei; Dumoncel, Jean; de Beer, Frikkie; Hoffman, Jakobus; Thackeray, John Francis; Duployer, Benjamin; Tenailleau, Christophe; Braga, José

2016-07-01

The appearance of the earliest members of the genus Homo in South Africa represents a key event in human evolution. Although enamel thickness and enamel dentine junction (EDJ) morphology preserve important information about hominin systematics and dietary adaptation, these features have not been sufficiently studied with regard to early Homo. We used micro-CT to compare enamel thickness and EDJ morphology among the mandibular postcanine dentitions of South African early hominins (N = 30) and extant Homo sapiens (N = 26), with special reference to early members of the genus Homo. We found that South African early Homo shows a similar enamel thickness distribution pattern to modern humans, although three-dimensional average and relative enamel thicknesses do not distinguish australopiths, early Homo, and modern humans particularly well. Based on enamel thickness distributions, our study suggests that a dietary shift occurred between australopiths and the origin of the Homo lineage. We also observed that South African early Homo postcanine EDJ combined primitive traits seen in australopith molars with derived features observed in modern human premolars. Our results confirm that some dental morphological patterns in later Homo actually occurred early in the Homo lineage, and highlight the taxonomic value of premolar EDJ morphology in hominin species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Teaching African-American Children.

ERIC Educational Resources Information Center

Horton, Harold

1994-01-01

Examines the historical blighting of African-American slaves' minds, which stripped them of their African culture. Examines the effect on African-American children, as well as other children of color. Offers suggestions for coping with the problems of modern schools in terms of respecting and teaching these children that the system is the problem,…

African American Students in Counselor Education Programs: Perceptions of Their Experiences

ERIC Educational Resources Information Center

Henfield, Malik S.; Owens, Delila; Witherspoon, Sheila

2011-01-01

The authors explored 11 African American doctoral students' perceptions of their experiences in counselor education programs, and their findings are presented. Using a phenomenological methodological framework, the authors investigated the various systems of support that students use as they navigate their respective programs. Human agency was the…

African origin of the malaria parasite Plasmodium vivax.

PubMed

Liu, Weimin; Li, Yingying; Shaw, Katharina S; Learn, Gerald H; Plenderleith, Lindsey J; Malenke, Jordan A; Sundararaman, Sesh A; Ramirez, Miguel A; Crystal, Patricia A; Smith, Andrew G; Bibollet-Ruche, Frederic; Ayouba, Ahidjo; Locatelli, Sabrina; Esteban, Amandine; Mouacha, Fatima; Guichet, Emilande; Butel, Christelle; Ahuka-Mundeke, Steve; Inogwabini, Bila-Isia; Ndjango, Jean-Bosco N; Speede, Sheri; Sanz, Crickette M; Morgan, David B; Gonder, Mary K; Kranzusch, Philip J; Walsh, Peter D; Georgiev, Alexander V; Muller, Martin N; Piel, Alex K; Stewart, Fiona A; Wilson, Michael L; Pusey, Anne E; Cui, Liwang; Wang, Zenglei; Färnert, Anna; Sutherland, Colin J; Nolder, Debbie; Hart, John A; Hart, Terese B; Bertolani, Paco; Gillis, Amethyst; LeBreton, Matthew; Tafon, Babila; Kiyang, John; Djoko, Cyrille F; Schneider, Bradley S; Wolfe, Nathan D; Mpoudi-Ngole, Eitel; Delaporte, Eric; Carter, Richard; Culleton, Richard L; Shaw, George M; Rayner, Julian C; Peeters, Martine; Hahn, Beatrice H; Sharp, Paul M

2014-01-01

Plasmodium vivax is the leading cause of human malaria in Asia and Latin America but is absent from most of central Africa due to the near fixation of a mutation that inhibits the expression of its receptor, the Duffy antigen, on human erythrocytes. The emergence of this protective allele is not understood because P. vivax is believed to have originated in Asia. Here we show, using a non-invasive approach, that wild chimpanzees and gorillas throughout central Africa are endemically infected with parasites that are closely related to human P. vivax. Sequence analyses reveal that ape parasites lack host specificity and are much more diverse than human parasites, which form a monophyletic lineage within the ape parasite radiation. These findings indicate that human P. vivax is of African origin and likely selected for the Duffy-negative mutation. All extant human P. vivax parasites are derived from a single ancestor that escaped out of Africa.

African origin of the malaria parasite Plasmodium vivax

PubMed Central

Liu, Weimin; Li, Yingying; Shaw, Katharina S.; Learn, Gerald H.; Plenderleith, Lindsey J.; Malenke, Jordan A.; Sundararaman, Sesh A.; Ramirez, Miguel A.; Crystal, Patricia A.; Smith, Andrew G.; Bibollet-Ruche, Frederic; Ayouba, Ahidjo; Locatelli, Sabrina; Esteban, Amandine; Mouacha, Fatima; Guichet, Emilande; Butel, Christelle; Ahuka-Mundeke, Steve; Inogwabini, Bila-Isia; Ndjango, Jean-Bosco N.; Speede, Sheri; Sanz, Crickette M.; Morgan, David B.; Gonder, Mary K.; Kranzusch, Philip J.; Walsh, Peter D.; Georgiev, Alexander V.; Muller, Martin N.; Piel, Alex K.; Stewart, Fiona A.; Wilson, Michael L.; Pusey, Anne E.; Cui, Liwang; Wang, Zenglei; Färnert, Anna; Sutherland, Colin J.; Nolder, Debbie; Hart, John A.; Hart, Terese B.; Bertolani, Paco; Gillis, Amethyst; LeBreton, Matthew; Tafon, Babila; Kiyang, John; Djoko, Cyrille F.; Schneider, Bradley S.; Wolfe, Nathan D.; Mpoudi-Ngole, Eitel; Delaporte, Eric; Carter, Richard; Culleton, Richard L.; Shaw, George M.; Rayner, Julian C.; Peeters, Martine; Hahn, Beatrice H.; Sharp, Paul M.

2014-01-01

Plasmodium vivax is the leading cause of human malaria in Asia and Latin America but is absent from most of central Africa due to the near fixation of a mutation that inhibits the expression of its receptor, the Duffy antigen, on human erythrocytes. The emergence of this protective allele is not understood because P. vivax is believed to have originated in Asia. Here we show, using a non-invasive approach, that wild chimpanzees and gorillas throughout central Africa are endemically infected with parasites that are closely related to human P. vivax. Sequence analyses reveal that ape parasites lack host specificity and are much more diverse than human parasites, which form a monophyletic lineage within the ape parasite radiation. These findings indicate that human P. vivax is of African origin and likely selected for the Duffy-negative mutation. All extant human P. vivax parasites are derived from a single ancestor that escaped out of Africa. PMID:24557500

An African Perspective on Peace Education: "Ubuntu" Lessons in Reconciliation

ERIC Educational Resources Information Center

Murithi, Tim

2009-01-01

This essay examines the value of educating for peace. It does this through a consideration of the African cultural world-view known as "ubuntu," which highlights the essential unity of humanity and emphasises the importance of constantly referring to the principles of empathy, sharing and cooperation in efforts to resolve our common…

Population Genomics of Sub-Saharan Drosophila melanogaster: African Diversity and Non-African Admixture

PubMed Central

Pool, John E.; Corbett-Detig, Russell B.; Sugino, Ryuichi P.; Stevens, Kristian A.; Cardeno, Charis M.; Crepeau, Marc W.; Duchen, Pablo; Emerson, J. J.; Saelao, Perot; Begun, David J.; Langley, Charles H.

2012-01-01

Drosophila melanogaster has played a pivotal role in the development of modern population genetics. However, many basic questions regarding the demographic and adaptive history of this species remain unresolved. We report the genome sequencing of 139 wild-derived strains of D. melanogaster, representing 22 population samples from the sub-Saharan ancestral range of this species, along with one European population. Most genomes were sequenced above 25X depth from haploid embryos. Results indicated a pervasive influence of non-African admixture in many African populations, motivating the development and application of a novel admixture detection method. Admixture proportions varied among populations, with greater admixture in urban locations. Admixture levels also varied across the genome, with localized peaks and valleys suggestive of a non-neutral introgression process. Genomes from the same location differed starkly in ancestry, suggesting that isolation mechanisms may exist within African populations. After removing putatively admixed genomic segments, the greatest genetic diversity was observed in southern Africa (e.g. Zambia), while diversity in other populations was largely consistent with a geographic expansion from this potentially ancestral region. The European population showed different levels of diversity reduction on each chromosome arm, and some African populations displayed chromosome arm-specific diversity reductions. Inversions in the European sample were associated with strong elevations in diversity across chromosome arms. Genomic scans were conducted to identify loci that may represent targets of positive selection within an African population, between African populations, and between European and African populations. A disproportionate number of candidate selective sweep regions were located near genes with varied roles in gene regulation. Outliers for Europe-Africa FST were found to be enriched in genomic regions of locally elevated cosmopolitan

African Non-Human Primates Host Diverse Enteroviruses.

PubMed

Mombo, Illich Manfred; Lukashev, Alexander N; Bleicker, Tobias; Brünink, Sebastian; Berthet, Nicolas; Maganga, Gael D; Durand, Patrick; Arnathau, Céline; Boundenga, Larson; Ngoubangoye, Barthélémy; Boué, Vanina; Liégeois, Florian; Ollomo, Benjamin; Prugnolle, Franck; Drexler, Jan Felix; Drosten, Christian; Renaud, François; Rougeron, Virginie; Leroy, Eric

2017-01-01

Enteroviruses (EVs) belong to the family Picornaviridae and are responsible for mild to severe diseases in mammals including humans and non-human primates (NHP). Simian EVs were first discovered in the 1950s in the Old World Monkeys and recently in wild chimpanzee, gorilla and mandrill in Cameroon. In the present study, we screened by PCR EVs in 600 fecal samples of wild apes and monkeys that were collected at four sites in Gabon. A total of 32 samples were positive for EVs (25 from mandrills, 7 from chimpanzees, none from gorillas). The phylogenetic analysis of VP1 and VP2 genes showed that EVs identified in chimpanzees were members of two human EV species, EV-A and EV-B, and those identified in mandrills were members of the human species EV-B and the simian species EV-J. The identification of two novel enterovirus types, EV-B112 in a chimpanzee and EV-B113 in a mandrill, suggests these NHPs could be potential sources of new EV types. The identification of EV-B107 and EV90 that were previously found in humans indicates cross-species transfers. Also the identification of chimpanzee-derived EV110 in a mandrill demonstrated a wide host range of this EV. Further research of EVs in NHPs would help understanding emergence of new types or variants, and evaluating the real risk of cross-species transmission for humans as well for NHPs populations.

Mental Health and African Americans

MedlinePlus

... than Non-Hispanic whites. The death rate from suicide for African American men was more than four ... for African American women, in 2014. However, the suicide rate for African Americans is 70% lower than ...

Youth in the New South Africa. Towards Policy Formulation. Main Report of the Co-operative Research Programme: South African Youth.

ERIC Educational Resources Information Center

Van Zyl Slabbert, F., Ed.; And Others

In view of the sweeping political and social changes in South Africa, the Human Sciences Research Council and other agencies established the Co-operative Research Programme: South African Youth, a program to undertake research on the problems, challenges, and opportunities facing South African youth. This report presents the information base of…

Race, genetics, and human reproductive strategies.

PubMed

Rushton, J P

1996-02-01

The international literature on racial differences is reviewed, novel data are reported, and a distinct pattern is found. People of east Asian ancestry and people of African ancestry average at opposite ends of a continuum, with people of European ancestry averaging intermediately, albeit with much variability within each major race. The racial matrix emerges from measures taken of reproductive behavior, sex hormones, twinning rate, speed of physical maturation, personality, family stability, brain size, intelligence, law abidingness, and social organization. An evolutionary theory of human reproduction is proposed, familiar to biologists as the r-K scale of reproductive strategies. At one end of this scale are r-strategies, which emphasize high reproductive rates; at the other end are K-strategies, which emphasize high levels of parental investment. This scale is generally used to compare the life histories of widely disparate species, but here it is used to describe the immensely smaller variations among human races. It is hypothesized that, again on average, Mongoloid people are more K-selected than Caucasoids, who are more K-selected than Negroids. The r-K scale of reproductive strategies is also mapped on to human evolution. Genetic distances indicate that Africans emerged from the ancestral hominid line about 200,000 years ago, with an African/non-African split about 110,000 years ago, and a Caucasoid/Mongoloid split about 41,000 years ago. Such an ordering fits with and explains how and why the variables cluster.

Malignant lymphoma in african lions (panthera leo).

PubMed

Harrison, T M; McKnight, C A; Sikarskie, J G; Kitchell, B E; Garner, M M; Raymond, J T; Fitzgerald, S D; Valli, V E; Agnew, D; Kiupel, M

2010-09-01

Malignant lymphoma has become an increasingly recognized problem in African lions (Panthera leo). Eleven African lions (9 male and 2 female) with clinical signs and gross and microscopic lesions of malignant lymphoma were evaluated in this study. All animals were older adults, ranging in age from 14 to 19 years. Immunohistochemically, 10 of the 11 lions had T-cell lymphomas (CD3(+), CD79a(-)), and 1 lion was diagnosed with a B-cell lymphoma (CD3(-), CD79a(+)). The spleen appeared to be the primary site of neoplastic growth in all T-cell lymphomas, with involvement of the liver (6/11) and regional lymph nodes (5/11) also commonly observed. The B-cell lymphoma affected the peripheral lymph nodes, liver, and spleen. According to the current veterinary and human World Health Organization classification of hematopoietic neoplasms, T-cell lymphoma subtypes included peripheral T-cell lymphoma (4/11), precursor (acute) T-cell lymphoblastic lymphoma/leukemia (2/11), chronic T-cell lymphocytic lymphoma/leukemia (3/11), and T-zone lymphoma (1/11). The single B-cell lymphoma subtype was consistent with diffuse large B-cell lymphoma. Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) testing by immunohistochemistry on sections of malignant lymphoma was negative for all 11 lions. One lion was seropositive for FeLV. In contrast to domestic and exotic cats, in which B-cell lymphomas are more common than T-cell lymphomas, African lions in this study had malignant lymphomas that were primarily of T-cell origin. Neither FeLV nor FIV, important causes of malignant lymphoma in domestic cats, seems to be significant in the pathogenesis of malignant lymphoma in African lions.

An examination of acceptability of HPV vaccination among African American women and Latina immigrants.

PubMed

Scarinci, Isabel C; Garcés-Palacio, Isabel C; Partridge, Edward E

2007-10-01

This study examined the acceptability of preventive human papillomavirus (HPV) vaccination among Latina immigrants and African American women through eight focus groups (n = 55, 28 Latinas and 27 African Americans). Latinas were between 17 and 39 years old (x = 27.9) and African Americans between 19 and 39 (x = 24.3). Approximately 86% of Latinas and 7% of African Americans were married or living with a partner; 10.7% of Latinas and 53.8% of African Americans reported having health insurance; 60.7% of Latinas and 77.8% of African Americans had never heard about HPV. Following a brief presentation about cervical cancer and HPV, participants were questioned about the acceptability of a preventive HPV vaccine. Overall, both groups indicated that an HPV preventive vaccine would be acceptable. However, African Americans were more skeptical, citing concerns about effectiveness and side effects. Another African American concern was whether vaccinated women would perceive themselves as being protected from HPV, leading them to increased promiscuity or unprotected sex. African Americans' motivating factors for vaccine use included receiving education/information about the vaccine, affordable prices, good results in trials, and knowing others who had already gotten vaccinated. Latina immigrants, on the other hand, unanimously stated that they would get the vaccine. However, they believed that multiple credible sources of information (educational talks, doctor's office, television, churches, and other women) needed to promote the vaccine before the Latino community at large would accept it. These findings suggest that unique educational strategies need to be developed, based on the needs and perceptions of the targeted audience, in order to achieve wide-spread acceptability of this vaccine.

Modern human origins: progress and prospects.

PubMed Central

Stringer, Chris

2002-01-01

The question of the mode of origin of modern humans (Homo sapiens) has dominated palaeoanthropological debate over the last decade. This review discusses the main models proposed to explain modern human origins, and examines relevant fossil evidence from Eurasia, Africa and Australasia. Archaeological and genetic data are also discussed, as well as problems with the concept of 'modernity' itself. It is concluded that a recent African origin can be supported for H. sapiens, morphologically, behaviourally and genetically, but that more evidence will be needed, both from Africa and elsewhere, before an absolute African origin for our species and its behavioural characteristics can be established and explained. PMID:12028792

Consequences of non-intervention for infectious disease in African great apes.

PubMed

Ryan, Sadie J; Walsh, Peter D

2011-01-01

Infectious disease has recently joined poaching and habitat loss as a major threat to African apes. Both "naturally" occurring pathogens, such as Ebola and Simian Immunodeficiency Virus (SIV), and respiratory pathogens transmitted from humans, have been confirmed as important sources of mortality in wild gorillas and chimpanzees. While awareness of the threat has increased, interventions such as vaccination and treatment remain controversial. Here we explore both the risk of disease to African apes, and the status of potential responses. Through synthesis of published data, we summarize prior disease impact on African apes. We then use a simple demographic model to illustrate the resilience of a well-known gorilla population to disease, modeled on prior documented outbreaks. We found that the predicted recovery time for this specific gorilla population from a single outbreak ranged from 5 years for a low mortality (4%) respiratory outbreak, to 131 years for an Ebola outbreak that killed 96% of the population. This shows that mortality rates comparable to those recently reported for disease outbreaks in wild populations are not sustainable. This is particularly troubling given the rising pathogen risk created by increasing habituation of wild apes for tourism, and the growth of human populations surrounding protected areas. We assess potential future disease spillover risk in terms of vaccination rates amongst humans that may come into contact with wild apes, and the availability of vaccines against potentially threatening diseases. We discuss and evaluate non-interventionist responses such as limiting tourist access to apes, community health programs, and safety, logistic, and cost issues that constrain the potential of vaccination. © 2011 Ryan and Walsh.

Consequences of Non-Intervention for Infectious Disease in African Great Apes

PubMed Central

Ryan, Sadie J.; Walsh, Peter D.

2011-01-01

Infectious disease has recently joined poaching and habitat loss as a major threat to African apes. Both “naturally” occurring pathogens, such as Ebola and Simian Immunodeficiency Virus (SIV), and respiratory pathogens transmitted from humans, have been confirmed as important sources of mortality in wild gorillas and chimpanzees. While awareness of the threat has increased, interventions such as vaccination and treatment remain controversial. Here we explore both the risk of disease to African apes, and the status of potential responses. Through synthesis of published data, we summarize prior disease impact on African apes. We then use a simple demographic model to illustrate the resilience of a well-known gorilla population to disease, modeled on prior documented outbreaks. We found that the predicted recovery time for this specific gorilla population from a single outbreak ranged from 5 years for a low mortality (4%) respiratory outbreak, to 131 years for an Ebola outbreak that killed 96% of the population. This shows that mortality rates comparable to those recently reported for disease outbreaks in wild populations are not sustainable. This is particularly troubling given the rising pathogen risk created by increasing habituation of wild apes for tourism, and the growth of human populations surrounding protected areas. We assess potential future disease spillover risk in terms of vaccination rates amongst humans that may come into contact with wild apes, and the availability of vaccines against potentially threatening diseases. We discuss and evaluate non-interventionist responses such as limiting tourist access to apes, community health programs, and safety, logistic, and cost issues that constrain the potential of vaccination. PMID:22216162

The Teacher-Student Interactions and Academic Achievement of African American and African Immigrant Males

ERIC Educational Resources Information Center

Hussein, Hassen

2017-01-01

This quantitative survey questionnaires study compared the teacher-student interactions (TSI) and academic achievement of African-American and African immigrant undergraduate males. The academic achievement gap between different population groups provided the impetus for the study. While African Americans have been described as under-achievers in…

A review of the traditional use of southern African medicinal plants for the treatment of selected parasite infections affecting humans.

PubMed

Cock, I E; Selesho, M I; Van Vuuren, S F

2018-06-28

Worldwide, more than three billion cases of parasitic disease are reported yearly and it is likely that this figure is substantially under-estimated. Approximately one in six people globally are estimated to be infected with at least one parasite species annually. In South Africa, the prevalence of Schistosoma haematobium (bilharzia) and intestinal worms and helminths are particularly high, especially in children and in crowded or poorer rural communities with inadequate sanitation and nutrition. Despite alarmingly high estimates, medical research into parasitic diseases remains neglected and only malaria receives significant attention and funding. Traditional medicines have been used for centuries in Africa by multiple ethnic groups and many people rely on these healing systems as their primary healthcare modality. The traditional use of South African medicinal plants to treat parasite infestations is relatively well documented, and it is important to link these traditional uses to scientific evidence validating efficacy. To document the medicinal plants used for parasitic infections and critically review the literature on the anti-parasitic properties of South African plants against some neglected parasitic diseases. A review of the literature (ethnobotanical books and publications documenting traditional plant use) was undertaken related to specific medicinal use for parasitic infections in Southern Africa. Inclusion criteria focused on human use. Exclusion criteria included veterinary use and malaria due to the extensive nature of these subject matters. An in-depth analysis of previous studies was undertaken and future prospectives are considered. In particular, bilharzia, gastrointestinal worms and helminths, ectoparasites, trichomoniasis, leishmaniasis and trypanosomiasis are reviewed with special emphasis on the gaps in research. Despite the availability of relatively extensive ethnobotanical records on the anti-parasitic properties of southern African

A 3 million year index for North African humidity/aridity and the implication of potential pan-African Humid periods

NASA Astrophysics Data System (ADS)

Grant, Katharine M.; Rohling, Eelco J.; Westerhold, Thomas; Zabel, Matthias; Heslop, David; Konijnendijk, Tiuri; Lourens, Lucas

2017-09-01

Mediterranean sediments are valuable archives of both African monsoon variability and higher-latitude climate processes, and can also be used to provide an environmental context for early human migrations and settlements. However, the long history of Mediterranean palaeoclimate studies largely pre-dates the advent of widespread x-ray fluorescence (XRF) core-scanning, so there are few continuous and high-resolution geochemical records from this key region that extend beyond the last glacial cycle. Here we present XRF core-scanning results for ODP Site 967 (Eastern Mediterranean) that have been fully-calibrated into element concentrations spanning the last 3 million years (My). Comparison with independent geochemical data from conventional XRF highlights disparities for certain element/element ratios, thus suggesting the need for caution when taking ratios of scanning XRF data. Principal component analysis of the calibrated XRF dataset reveals two dominant components: detrital inputs (PC1) and a 'sapropel' (≈monsoon run-off) signal (PC2), which we use to establish a new orbitally-tuned chronology. We observe inverse covariation between PC2 and a previously published aeolian dust record from ODP Site 967 (Larrasoaña et al., 2003), and combine these records to produce a composite index of humidity and aridity for the wider North African region over the past 3 My. We propose that by combining run-off and dust signals in a single metric, our index captures the effects of both strengthening/northward migration (increased run-off) and weakening/southward retreat (increased dust) of the North African monsoon. Comparison of the index with published records of Northwest and East African palaeohumidity suggests that it tracks the timing of ;Green Sahara Periods; throughout the Plio-Pleistocene, and that at least 30 of these intervals coincided with increased humidity across East Africa. We tentatively suggest that these specific episodes may be termed ;pan-African Humid

Study shows aspirin reduces the risk and recurrence of prostate cancer in African-American men | Center for Cancer Research

Cancer.gov

African-American men who take a daily dose of aspirin experience a significantly lower risk of developing advanced prostate cancer – the aggressive and deadly form of the disease – than African-American men who do not regularly use aspirin, according to a study from the Center for Cancer Research (CCR) Laboratory of Human Carcinogenesis. Learn more...

Genome-wide scan of 29,141 African Americans finds no evidence of directional selection since admixture.

PubMed

Bhatia, Gaurav; Tandon, Arti; Patterson, Nick; Aldrich, Melinda C; Ambrosone, Christine B; Amos, Christopher; Bandera, Elisa V; Berndt, Sonja I; Bernstein, Leslie; Blot, William J; Bock, Cathryn H; Caporaso, Neil; Casey, Graham; Deming, Sandra L; Diver, W Ryan; Gapstur, Susan M; Gillanders, Elizabeth M; Harris, Curtis C; Henderson, Brian E; Ingles, Sue A; Isaacs, William; De Jager, Phillip L; John, Esther M; Kittles, Rick A; Larkin, Emma; McNeill, Lorna H; Millikan, Robert C; Murphy, Adam; Neslund-Dudas, Christine; Nyante, Sarah; Press, Michael F; Rodriguez-Gil, Jorge L; Rybicki, Benjamin A; Schwartz, Ann G; Signorello, Lisa B; Spitz, Margaret; Strom, Sara S; Tucker, Margaret A; Wiencke, John K; Witte, John S; Wu, Xifeng; Yamamura, Yuko; Zanetti, Krista A; Zheng, Wei; Ziegler, Regina G; Chanock, Stephen J; Haiman, Christopher A; Reich, David; Price, Alkes L

2014-10-02

The extent of recent selection in admixed populations is currently an unresolved question. We scanned the genomes of 29,141 African Americans and failed to find any genome-wide-significant deviations in local ancestry, indicating no evidence of selection influencing ancestry after admixture. A recent analysis of data from 1,890 African Americans reported that there was evidence of selection in African Americans after their ancestors left Africa, both before and after admixture. Selection after admixture was reported on the basis of deviations in local ancestry, and selection before admixture was reported on the basis of allele-frequency differences between African Americans and African populations. The local-ancestry deviations reported by the previous study did not replicate in our very large sample, and we show that such deviations were expected purely by chance, given the number of hypotheses tested. We further show that the previous study's conclusion of selection in African Americans before admixture is also subject to doubt. This is because the FST statistics they used were inflated and because true signals of unusual allele-frequency differences between African Americans and African populations would be best explained by selection that occurred in Africa prior to migration to the Americas. Copyright © 2014 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

High-Risk Human Papillomavirus Is Associated with HIV Acquisition among South African Female Sex Workers

PubMed Central

Auvert, Bertran; Marais, Dianne; Lissouba, Pascale; Zarca, Kevin; Ramjee, Gita; Williamson, Anna-Lise

2011-01-01

Background. Mounting evidence suggests an association between human papillomavirus (HPV) and HIV acquisition. This study aimed to explore this association among South African female sex workers (FSWs). Methods. We used data from 88 HIV-negative FSWs who participated in a vaginal gel (COL-1492) trial. Cervicovaginal rinse samples, obtained before HIV-seroconversion, were genotyped into high-risk (HR-) and low-risk (LR-) HPV. HIV-adjusted hazard ratios (aHRs) and 95% confidence intervals (CI) were estimated using Cox survival analysis. Results. HR- and LR-HPV prevalences were 70.5% (95% CI : 60.5–79.2) and 60.2% (95% CI : 49.9–70.0), respectively. Twenty-five women HIV seroconverted. Controlling for background characteristics and other sexually transmitted infections, HIV aHR increased by a factor of 1.7 (95% CI : 1.01–2.7, P linear trend = 0.045) for an increase of one unit of the number of HR-HPV genotypes. Conclusions. HIV seroconversion among FSWs is associated with genital HR-HPV infection. Further investigation is warranted, including testing the possible protective effect of available HPV vaccines on HIV acquisition. PMID:21804752

A Teacher's Guide to African Narratives. Studies in African Literature.

ERIC Educational Resources Information Center

O'Brien, Sara Talis

This guide is designed to help secondary school teachers include African literature in their classes. It furnishes English and social studies teachers with a foundation for teaching African literature by offering critical commentary on the texts themselves. A synthesis of anthropological and historical material is presented to help both teachers…

East African ROAD

NASA Astrophysics Data System (ADS)

Tekle, Kelali

2016-10-01

In the developing world astronomy had been treated as the science of elites. As a result of this overwhelming perception, astronomy compared with other applied sciences has got less attention and its role in development has been insignificant. However, the IAU General Assembly decision in 2009 opened new opportunity for countries and professionals to deeply look into Astronomy and its role in development. Then, the subsequent establishment of regional offices in the developing world is helping countries to integrate astronomy with other earth and space based sciences so as to progressively promote its scientific and development importance. Gradually nations have come to know that space is the frontier of tomorrow and the urgency of preeminence on space frontier starts at primary school and ascends to tertiary education. For this to happen, member nations in east African region have placed STEM education at the center of their education system. For instance, Ethiopian has changed University enrollment strategy to be in favor of science and engineering subjects, i.e. every year seventy percent of new University entrants join science and engineering fields while thirty percent social science and humanities. Such bold actions truly promote astronomy to be conceived as gateway to science and technology. To promote the concept of astronomy for development the East African regional office has actually aligned it activities to be in line with the focus areas identified by the IAU strategy (2010 to 2020).

Physico-chemical characterization of African urban aerosols (Bamako in Mali and Dakar in Senegal) and their toxic effects in human bronchial epithelial cells: description of a worrying situation.

PubMed

Val, Stéphanie; Liousse, Cathy; Doumbia, El Hadji Thierno; Galy-Lacaux, Corinne; Cachier, Hélène; Marchand, Nicolas; Badel, Anne; Gardrat, Eric; Sylvestre, Alexandre; Baeza-Squiban, Armelle

2013-04-02

The involvement of particulate matter (PM) in cardiorespiratory diseases is now established in developed countries whereas in developing areas such as Africa with a high level of specific pollution, PM pollution and its effects are poorly studied. Our objective was to characterize the biological reactivity of urban African aerosols on human bronchial epithelial cells in relation to PM physico-chemical properties to identify toxic sources. Size-speciated aerosol chemical composition was analyzed in Bamako (BK, Mali, 2 samples with one having desert dust event BK1) and Dakar (DK; Senegal) for Ultrafine UF, Fine F and Coarse C PM. PM reactivity was studied in human bronchial epithelial cells investigating six biomarkers (oxidative stress responsive genes and pro-inflammatory cytokines). PM mass concentrations were mainly distributed in coarse mode (60%) and were impressive in BK1 due to the desert dust event. BK2 and DK samples showed a high content of total carbon characteristic of urban areas. The DK sample had huge PAH quantities in bulk aerosol compared with BK that had more water soluble organic carbon and metals. Whatever the site, UF and F PM triggered the mRNA expression of the different biomarkers whereas coarse PM had little or no effect. The GM-CSF biomarker was the most discriminating and showed the strongest pro-inflammatory effect of BK2 PM. The analysis of gene expression signature and of their correlation with main PM compounds revealed that PM-induced responses are mainly related to organic compounds. The toxicity of African aerosols is carried by the finest PM as with Parisian aerosols, but when considering PM mass concentrations, the African population is more highly exposed to toxic particulate pollution than French population. Regarding the prevailing sources in each site, aerosol biological impacts are higher for incomplete combustion sources resulting from two-wheel vehicles and domestic fires than from diesel vehicles (Dakar). Desert dust

Attention HIV: older African American women define sexual risk.

PubMed

McCord, Laneshia R

2014-01-01

Understanding sexual-risk behaviours as defined by a culture presents new challenges for human service professionals. Older African American women constitute the fastest growing group of new cases of HIV in the USA. With heterosexual sex as the primary mode of transmission among this group, there exist minimal programmes that are culture and age-specific in terms of primary and secondary prevention. In an attempt to address this gap in knowledge, this study examined how a group of older African American women defined sexual-risk behaviour. A focus group was conducted with seven women age 45 and older, who were recruited from a community centre. This paper examines the way that sexual-risk behaviour was defined through thematic analysis and conceptualises the locus of sexual risk behaviour as defined by the participants. The major theme of the study was social prescription, how to behave sexually as an ageing adult. Underlying ideas that arose were that unprotected sex occurred out of habit, that impulsivity was associated with risky sex and that older women needed to be aware of warning signs and behaviours of potential mates. Micro- and macro-level implications for human service professionals are discussed.

The South African Navy and African Maritime Security

DTIC Science & Technology

2012-01-01

under a new name, the South African Sea- ward Defence Force (SDF).8 The service experienced rapid growth , and by 1945 B A K E R 147 the authorized...1,553,000 square kilometers) exclu- sive economic zone (EEZ).42 Exacerbating the situation is a much-eroded South African Air Force maritime patrol...addressed by the government on a very small tax base) and must be set against a realistic assessment of the threat environment that South Africa is

Solving the African Climate Observation Puzzle, and Concurrently Building Capacity

NASA Astrophysics Data System (ADS)

Selker, J. S.; Van De Giesen, N.; Annor, F. O.; Hochreutener, R.; Jachens, E. R.

2017-12-01

The Trans-African Hydro-Meteorological Observatory (TAHMO.org) is directly addressing basic issues of climate observation, climate science, and education through a novel public-private partnership. With 500 stations now reporting from over 20 African countries, TAHMO is the largest single source of continental-scale weather and climate data for Africa. Working directly with national meteorological agencies, TAHMO first builds local human capacity and real-time data to the host country. TAHMO also provides all of these data free of charge to all researchers and teams seeking to develop peer-reviewed scientific contributions. This will be the basis of a whole new level of observation-informed science for the African continent. Most TAHMO stations are housed at African schools, with a local host-teacher who attends to basic day-to-day cleaning. These schools also receive free curricular support providing geographic, mathematical, statistical, hydrologic, and meteorological lessons that connect student to their environment and creates climate-aware citizens, which we believe is the most fundamental element of developing a climate-resilient society. Installation of these stations have been made possible through the support of private companies like IBM and development programmes through the Global Resilience Partnership, World Bank, USAID among others. The availability of these new data sets will help generate more accurate weather forecasts which will be made freely available across the African continent. TAHMO leverages low-cost cell phone data transmission with solid-state sensor technology (provided by the METER corporation) to provide a cost-effective, sustainable, and transformative solution to the climate observation gap in Africa.

Association of ABCB1 genetic variants with renal function in Africans and in Caucasians

PubMed Central

Bochud, Murielle; Eap, Chin B; Maillard, Marc; Johnson, Toby; Vollenweider, Peter; Bovet, Pascal; Elston, Robert C; Bergmann, Sven; Beckmann, Jacques S; Waterworth, Dawn M; Mooser, Vincent; Gabriel, Anne; Burnier, Michel

2008-01-01

Background The P-glycoprotein, encoded by the ABCB1 gene, is expressed in human endothelial and mesangial cells, which contribute to control renal plasma flow and glomerular filtration rate. We investigated the association of ABCB1 variants with renal function in African and Caucasian subjects. Methods In Africans (290 subjects from 62 pedigrees), we genotyped the 2677G>T and 3435 C>T ABCB1 polymorphisms. Glomerular filtration rate (GFR) was measured using inulin clearance and effective renal plasma flow (ERPF) using para-aminohippurate clearance. In Caucasians (5382 unrelated subjects), we analyzed 30 SNPs located within and around ABCB1, using data from the Affymetrix 500 K chip. GFR was estimated using the simplified Modification of the Diet in Renal Disease (MDRD) and Cockcroft-Gault equations. Results In Africans, compared to the reference genotype (GG or CC), each copy of the 2677T and 3435T allele was associated, respectively, with: GFR higher by 10.6 ± 2.9 (P < 0.001) and 4.4 ± 2.3 (P = 0.06) mL/min; ERPF higher by 47.5 ± 11.6 (P < 0.001) and 28.1 ± 10.5 (P = 0.007) mL/min; and renal resistances lower by 0.016 ± 0.004 (P < 0.001) and 0.011 ± 0.004 (P = 0.004) mm Hg/mL/min. In Caucasians, we identified 3 polymorphisms in the ABCB1 gene that were strongly associated with all estimates of GFR (smallest P value = 0.0006, overall P = 0.014 after multiple testing correction). Conclusion Variants of the ABCB1 gene were associated with renal function in both Africans and Caucasians and may therefore confer susceptibility to nephropathy in humans. If confirmed in other studies, these results point toward a new candidate gene for nephropathy in humans. PMID:18518969

The environmental context for the origins of modern human diversity: a synthesis of regional variability in African climate 150,000-30,000 years ago.

PubMed

Blome, Margaret Whiting; Cohen, Andrew S; Tryon, Christian A; Brooks, Alison S; Russell, Joellen

2012-05-01

We synthesize African paleoclimate from 150 to 30 ka (thousand years ago) using 85 diverse datasets at a regional scale, testing for coherence with North Atlantic glacial/interglacial phases and northern and southern hemisphere insolation cycles. Two major determinants of circum-African climate variability over this time period are supported by principal components analysis: North Atlantic sea surface temperature (SST) variations and local insolation maxima. North Atlantic SSTs correlated with the variability found in most circum-African SST records, whereas the variability of the majority of terrestrial temperature and precipitation records is explained by local insolation maxima, particularly at times when solar radiation was intense and highly variable (e.g., 150-75 ka). We demonstrate that climates varied with latitude, such that periods of relatively increased aridity or humidity were asynchronous across the northern, eastern, tropical and southern portions of Africa. Comparisons of the archaeological, fossil, or genetic records with generalized patterns of environmental change based solely on northern hemisphere glacial/interglacial cycles are therefore imprecise. We compare our refined climatic framework to a database of 64 radiometrically-dated paleoanthropological sites to test hypotheses of demographic response to climatic change among African hominin populations during the 150-30 ka interval. We argue that at a continental scale, population and climate changes were asynchronous and likely occurred under different regimes of climate forcing, creating alternating opportunities for migration into adjacent regions. Our results suggest little relation between large scale demographic and climate change in southern Africa during this time span, but strongly support the hypothesis of hominin occupation of the Sahara during discrete humid intervals ~135-115 ka and 105-75 ka. Hominin populations in equatorial and eastern Africa may have been buffered from the

'Walk with your head high': African and African-Caribbean fatherhood, children's mental well-being and social capital.

PubMed

Williams, Robert; Hewison, Alistair; Wagstaff, Chris; Randall, Duncan

2012-01-01

The findings presented in this article were unanticipated and came to light during a study which investigated African and African-Caribbean fathers' views about preventive primary care services. This article reports findings which indicate that African and African-Caribbean fathers strive to enable and protect children's mental well-being and create social, cultural and symbolic forms of capital. It also seeks to identify implications for health and social care policy and practice in England. There is limited literature examining African and African-Caribbean fathers' health experiences in England. Consequently an exploratory research approach was required. This involved nine, in-depth, semi-structured qualitative group interviews undertaken with 46 African and African-Caribbean fathers. The data were analysed thematically using abductive reasoning, informed by Bourdieu's theoretical work. Fathers were striving to enable and protect children's mental well-being through providing authoritative, loving, affectionate fatherhood involving reasoning, good communication and promoting self-esteem. These practices were seen to be necessary if children were to prosper in a harsh social world characterised by structural hazards including racism, negative stereotypes and limited opportunities. The fathers reported their efforts to develop what Bourdieu has termed symbolic, cultural and social capital as means of promoting the mental well-being of their children and the children of others. The implications for theory, future research, public health policy and practice, in relation to the needs of African and African-Caribbean fathers and families, are also discussed, with specific focus on how to realise the potential of African and African-Caribbean fathers' positive contributions to family and community health.

Psychological Misdiagnosis of African Americans.

ERIC Educational Resources Information Center

Garretson, Deborah J.

1993-01-01

Reviews historical and current problems with making accurate psychological diagnoses of African Americans. Suggests that misdiagnosis is strongly related to pathologization of African-American culture itself. Explores diagnostic process, stereotypes of African-American psychopathology, cultural differences in values and life stressors, and…

PubMed Central

Jannin, J.; Moulia-Pelat, J. P.; Chanfreau, B.; Penchenier, L.; Louis, J. P.; Nzaba, P.; de La Baume, F. E.; Eozenou, P.; Cattand, P.

1993-01-01

A case-control study was carried out in the Congo to define a scoring system based on a number of clinical and epidemiological criteria of African trypanosomiasis due to Trypanosoma brucei gambiense which could be used by peripheral health services to establish a diagnosis. The survey comprised 163 cases and 326 controls. Clinical signs and symptoms were fever, headache, pruritus and skin lesions due to scratching, diarrhoea, oedema, cervical adenopathies, sleep rhythm disturbances, changes in appetite, amenorrhoea or impotence, mental confusion, neurological signs, and other minor clinical disturbances. Other criteria were a history of previous trypanosomiasis and the presence of domestic animals in the home environment. Analysis of the results showed that neither a single criterion nor a group of criteria is pathognomonic for the disease. The selected criteria do not allow discrimination of sleeping sickness patients among suspected individuals who present themselves. A scoring system is therefore of little use at the peripheral level of health services, particularly when considering the additional workload involved. The low diagnostic value of these clinical signs and symptoms and other indicators in African trypanosomiasis stresses the difficulty in developing an early warning tool for an integrated control strategy in primary health care. PMID:8490985

Business United in Leadership Development: Alumni Perceptions of a Program Promoting Business as a Degree Program and Career for African Americans

ERIC Educational Resources Information Center

Brandi, Jay T.

2004-01-01

According to a recent Society for Human Resource Management (SHRM) study, racial and ethnic minorities, to include African Americans, are represented on only about 4% of Fortune 500 company boards of directors. The underrepresentation of African Americans in leadership roles in business has implications that reach far beyond the boundaries of…

Using detergent to enhance detection sensitivity of African trypanosomes in human CSF and blood by loop-mediated isothermal amplification (LAMP).

PubMed

Grab, Dennis J; Nikolskaia, Olga V; Inoue, Noboru; Thekisoe, Oriel M M; Morrison, Liam J; Gibson, Wendy; Dumler, J Stephen

2011-08-01

The loop-mediated isothermal amplification (LAMP) assay, with its advantages of simplicity, rapidity and cost effectiveness, has evolved as one of the most sensitive and specific methods for the detection of a broad range of pathogenic microorganisms including African trypanosomes. While many LAMP-based assays are sufficiently sensitive to detect DNA well below the amount present in a single parasite, the detection limit of the assay is restricted by the number of parasites present in the volume of sample assayed; i.e. 1 per µL or 10(3) per mL. We hypothesized that clinical sensitivities that mimic analytical limits based on parasite DNA could be approached or even obtained by simply adding detergent to the samples prior to LAMP assay. For proof of principle we used two different LAMP assays capable of detecting 0.1 fg genomic DNA (0.001 parasite). The assay was tested on dilution series of intact bloodstream form Trypanosoma brucei rhodesiense in human cerebrospinal fluid (CSF) or blood with or without the addition of the detergent Triton X-100 and 60 min incubation at ambient temperature. With human CSF and in the absence of detergent, the LAMP detection limit for live intact parasites using 1 µL of CSF as the source of template was at best 10(3) parasites/mL. Remarkably, detergent enhanced LAMP assay reaches sensitivity about 100 to 1000-fold lower; i.e. 10 to 1 parasite/mL. Similar detergent-mediated increases in LAMP assay analytical sensitivity were also found using DNA extracted from filter paper cards containing blood pretreated with detergent before card spotting or blood samples spotted on detergent pretreated cards. This simple procedure for the enhanced detection of live African trypanosomes in biological fluids by LAMP paves the way for the adaptation of LAMP for the economical and sensitive diagnosis of other protozoan parasites and microorganisms that cause diseases that plague the developing world.

African American Suicide

MedlinePlus

African American Suicide Fact Sheet Based on 2012 Data (2014) Overview • In 2012, 2,357 African Americans completed suicide in the U.S. Of these, 1,908 (80. ... rate of 9.23 per 100,000). The suicide rate for females was 1.99 per 100, ...

Successfully Educating Our African-American Students

ERIC Educational Resources Information Center

Moncree-Moffett, Kareem

2013-01-01

The purpose of this empirical study was to explore the lived experiences of African American retired female teachers who have prior experience with educating urban African American students in public schools. Also explored are the experiences of active African American female teachers of urban African American students and comparisons are…

Human Scleral Structural Stiffness Increases More Rapidly With Age in Donors of African Descent Compared to Donors of European Descent

PubMed Central

Fazio, Massimo A.; Grytz, Rafael; Morris, Jeffrey S.; Bruno, Luigi; Girkin, Christopher A.; Downs, J. Crawford

2014-01-01

Purpose. We tested the hypothesis that the variation of peripapillary scleral structural stiffness with age is different in donors of European (ED) and African (AD) descent. Methods. Posterior scleral shells from normal eyes from donors of European (n = 20 pairs; previously reported) and African (n = 9 pairs) descent aged 0 and 90 years old were inflation tested within 48 hours post mortem. Scleral shells were pressurized from 5 to 45 mm Hg and the full-field, 3-dimensional (3D) deformation of the outer surface was recorded at submicrometric accuracy using speckle interferometry (ESPI). Mean maximum principal (tensile) strain of the peripapillary and midperipheral regions surrounding the optic nerve head (ONH) were fit using a functional mixed effects model that accounts for intradonor variability, same-race correlation, and spatial autocorrelation to estimate the effect of race on the age-related changes in mechanical scleral strain. Results. Mechanical tensile strain significantly decreased with age in the peripapillary sclera in the African and European descent groups (P < 0.001), but the age-related stiffening was significantly greater in the African descent group (P < 0.05). Maximum principal strain in the peripapillary sclera was significantly higher than in the midperipheral sclera for both ethnic groups. Conclusions. The sclera surrounding the ONH stiffens more rapidly with age in the African descent group compared to the European group. Stiffening of the peripapillary sclera with age may be related to the higher prevalence of glaucoma in the elderly and persons of African descent. PMID:25237162

Human scleral structural stiffness increases more rapidly with age in donors of African descent compared to donors of European descent.

PubMed

Fazio, Massimo A; Grytz, Rafael; Morris, Jeffrey S; Bruno, Luigi; Girkin, Christopher A; Downs, J Crawford

2014-09-18

We tested the hypothesis that the variation of peripapillary scleral structural stiffness with age is different in donors of European (ED) and African (AD) descent. Posterior scleral shells from normal eyes from donors of European (n = 20 pairs; previously reported) and African (n = 9 pairs) descent aged 0 and 90 years old were inflation tested within 48 hours post mortem. Scleral shells were pressurized from 5 to 45 mm Hg and the full-field, 3-dimensional (3D) deformation of the outer surface was recorded at submicrometric accuracy using speckle interferometry (ESPI). Mean maximum principal (tensile) strain of the peripapillary and midperipheral regions surrounding the optic nerve head (ONH) were fit using a functional mixed effects model that accounts for intradonor variability, same-race correlation, and spatial autocorrelation to estimate the effect of race on the age-related changes in mechanical scleral strain. Mechanical tensile strain significantly decreased with age in the peripapillary sclera in the African and European descent groups (P < 0.001), but the age-related stiffening was significantly greater in the African descent group (P < 0.05). Maximum principal strain in the peripapillary sclera was significantly higher than in the midperipheral sclera for both ethnic groups. The sclera surrounding the ONH stiffens more rapidly with age in the African descent group compared to the European group. Stiffening of the peripapillary sclera with age may be related to the higher prevalence of glaucoma in the elderly and persons of African descent. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Differential effects of the classroom on African American and non-African American's mathematics achievement.

PubMed

Schenke, Katerina; Nguyen, Tutrang; Watts, Tyler W; Sarama, Julie H; Clements, Douglas H

2017-08-01

We examined whether African American students differentially responded to dimensions of the observed classroom-learning environment compared with non-African American students. Further, we examined whether these dimensions of the classroom mediated treatment effects of a preschool mathematics intervention targeted at students from low-income families. Three observed dimensions of the classroom (teacher expectations and developmental appropriateness; teacher confidence and enthusiasm; and support for mathematical discourse) were evaluated in a sample of 1,238 preschool students in 101 classrooms. Using multigroup multilevel mediation where African American students were compared to non-African American students, we found that teachers in the intervention condition had higher ratings on the observed dimensions of the classroom compared with teachers in the control condition. Further, ratings on teacher expectations and developmental appropriateness had larger associations with the achievement of African American students than for non-African Americans. Findings suggest that students within the same classroom may react differently to that learning environment and that classroom learning environments could be structured in ways that are beneficial for students who need the most support.

The Africanization of honeybees (Apis mellifera L.) of the Yucatan: a study of a massive hybridization event across time.

PubMed

Clarke, Kylea E; Rinderer, Thomas E; Franck, Pierre; Quezada-Euán, Javier G; Oldroyd, Benjamin P

2002-07-01

Until recently, African and European subspecies of the honeybee (Apis mellifera L.) had been geographically separated for around 10,000 years. However, human-assisted introductions have caused the mixing of large populations of African and European subspecies in South and Central America, permitting an unprecedented opportunity to study a large-scale hybridization event using molecular analyses. We obtained reference populations from Europe, Africa, and South America and used these to provide baseline information for a microsatellite and mitochondrial analysis of the process of Africanization of the bees of the Yucatan Peninsula, Mexico. The genetic structure of the Yucatecan population has changed dramatically over time. The pre-Africanized Yucatecan population (1985) comprised bees that were most similar to samples from southeastern Europe and northern and western Europe. Three years after the arrival of Africanized bees (1989), substantial paternal gene flow had occurred from feral Africanized drones into the resident European population, but maternal gene flow from the invading Africanized population into the local population was negligible. However by 1998, there was a radical shift with both African nuclear alleles (65%) and African-derived mitochondria (61%) dominating the genomes of domestic colonies. We suggest that although European mitochondria may eventually be driven to extinction in the feral population, stable introgression of European nuclear alleles has occurred.

Comparative morphology of the hominin and African ape hyoid bone, a possible marker of the evolution of speech.

PubMed

Steele, James; Clegg, Margaret; Martelli, Sandra

2013-10-01

This study examines the morphology of the hyoid in three closely related species, Homo sapiens, Pan troglodytes, and Gorilla gorilla. Differences and similarities between the hyoids of these species are characterized and used to interpret the morphology and affi nities of the Dikika A. afarensis, Kebara 2 Neanderthal, and other fossil hominin hyoid bones. Humans and African apes are found to have distinct hyoid morphologies. In humans the maximum width across the distal tips of the articulated greater horns is usually slightly greater than the maximum length (distal greater horn tip to most anterior point of the hyoid body in the midline). A different pattern is usually found in the African ape hyoids, which have much greater maximum lengths. In humans, the hyoid body is also much more anteroposteriorly shallow in proportion to its height and width, and this is true for all age classes. The Dikika australopithecine hyoid body proportions are chimpanzeelike. A discriminant function analysis, using a larger subadult sample from the three extant species than that reported by Alemseged et al. (2006), confirms this finding. The Kebara hyoid dimensions (body alone, and articulated body and greater horns) are almost all within the observed range for human hyoids. Discriminant functions clearly distinguish human from African ape hyoids and classify the Kebara 2 hyoid as human (confirming the finding of Arensburg et al. 1989). Our virtual dissection of a chimpanzee air sac system shows its subhyoid extension into the dorsal hyoid body. Following Alemseged et al. (2006), the expanded bulla characteristic of the African ape and australopithecine hyoid body is therefore interpreted as refl ecting the presence of such a laryngeal air sac extension. Its absence in the human, Neanderthal, and H. heidelbergensis (Atapuerca SH) hyoids implicates the loss of the laryngeal air sacs as a derived Neanderthal and modern human trait, which evolved no later than the middle Pleistocene. If

Applying Social Psychological Models to Predicting HIV-Related Sexual Risk Behaviors Among African Americans

PubMed Central

Cochran, Susan D.; Mays, Vickie M.

2011-01-01

Existing models of attitude-behavior relationships, including the Health Belief Model, the Theory of Reasoned Action, and the Self-Efficacy Theory, are increasingly being used by psychologists to predict human immunodeficiency virus (HIV)-related risk behaviors. The authors briefly highlight some of the difficulties that might arise in applying these models to predicting the risk behaviors of African Americans. These social psychological models tend to emphasize the importance of individualistic, direct control of behavioral choices and deemphasize factors, such as racism and poverty, particularly relevant to that segment of the African American population most at risk for HIV infection. Applications of these models without taking into account the unique issues associated with behavioral choices within the African American community may fail to capture the relevant determinants of risk behaviors. PMID:23529205

Social inequalities, regional disparities and health inequity in North African countries.

PubMed

Boutayeb, Abdesslam; Helmert, Uwe

2011-05-31

During the last decades, North African countries have substantially improved economic, social and health conditions of their populations in average. In all countries, human development in general and life expectancy, literacy and per capita income in particular have increased. However, improvement was not equally shared between groups of different milieu, regions or level of income. Social inequalities and health inequity have persisted or even worsened. Data are generally scarce and few studies were devoted to this topic in North Africa as a region. In this paper, we carry out a comparative study on the achievements of these countries, not only in terms of human development and its components but also in terms of inequalities' reduction and health equity. This study is based on data available for comparison between North African countries. The main data sources are provided by reports released by the World Health Organisation (WHO), United Nations Development Programme (UNDP), United Nations Children's Fund (UNICEF), the World Bank, surveys such as Demographic Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS) and finally recent papers published on equity in different countries of the region. There is no doubt that education, health and human development in general have improved in North Africa during the last decades. Improvement was, however, uneven and unequally enjoyed by different socioeconomic groups. Indeed, each country included in this study shows large urban-rural disparities, discrepancies between advantaged and disadvantaged regions and cities; and unacceptable differences between rich and poor. Health inequity is particularly seen through access to health services and infant mortality. During the last decades, North African decision makers have endeavoured to improve social and economic conditions of their populations. Globally, health, education and living standard in general have substantially improved in average. However, North

Genetic analysis shows low levels of hybridization between African wildcats (Felis silvestris lybica) and domestic cats (F. s. catus) in South Africa.

PubMed

Le Roux, Johannes J; Foxcroft, Llewellyn C; Herbst, Marna; MacFadyen, Sandra

2015-01-01

Hybridization between domestic and wild animals is a major concern for biodiversity conservation, and as habitats become increasingly fragmented, conserving biodiversity at all levels, including genetic, becomes increasingly important. Except for tropical forests and true deserts, African wildcats occur across the African continent; however, almost no work has been carried out to assess its genetic status and extent of hybridization with domestic cats. For example, in South Africa it has been argued that the long-term viability of maintaining pure wildcat populations lies in large protected areas only, isolated from human populations. Two of the largest protected areas in Africa, the Kgalagadi Transfrontier and Kruger National Parks, as well as the size of South Africa and range of landscape uses, provide a model situation to assess how habitat fragmentation and heterogeneity influences the genetic purity of African wildcats. Using population genetic and home range data, we examined the genetic purity of African wildcats and their suspected hybrids across South Africa, including areas within and outside of protected areas. Overall, we found African wildcat populations to be genetically relatively pure, but instances of hybridization and a significant relationship between the genetic distinctiveness (purity) of wildcats and human population pressure were evident. The genetically purest African wildcats were found in the Kgalagadi Transfrontier Park, while samples from around Kruger National Park showed cause for concern, especially combined with the substantial human population density along the park's boundary. While African wildcat populations in South Africa generally appear to be genetically pure, with low levels of hybridization, our genetic data do suggest that protected areas may play an important role in maintaining genetic purity by reducing the likelihood of contact with domestic cats. We suggest that approaches such as corridors between protected areas

Relevance of East African Drill Cores to Human Evolution: the Case of the Olorgesailie Drilling Project

NASA Astrophysics Data System (ADS)

Potts, R.

2016-12-01

Drill cores reaching the local basement of the East African Rift were obtained in 2012 south of the Olorgesailie Basin, Kenya, 20 km from excavations that document key benchmarks in the origin of Homo sapiens. Sediments totaling 216 m were obtained from two drilling locations representing the past 1 million years. The cores were acquired to build a detailed environmental record spatially associated with the transition from Acheulean to Middle Stone Age technology and extensive turnover in mammalian species. The project seeks precise tests of how climate dynamics and tectonic events were linked with these transitions. Core lithology (A.K. Behrensmeyer), geochronology (A. Deino), diatoms (R.B. Owen), phytoliths (R. Kinyanjui), geochemistry (N. Rabideaux, D. Deocampo), among other indicators, show evidence of strong environmental variability in agreement with predicted high-eccentricity modulation of climate during the evolutionary transitions. Increase in hominin mobility, elaboration of symbolic behavior, and concurrent turnover in mammalian species indicating heightened adaptability to unpredictable ecosystems, point to a direct link between the evolutionary transitions and the landscape dynamics reflected in the Olorgesailie drill cores. For paleoanthropologists and Earth scientists, any link between evolutionary transitions and environmental dynamics requires robust evolutionary datasets pertinent to how selection, extinction, population divergence, and other evolutionary processes were impacted by the dynamics uncovered in drill core studies. Fossil and archeological data offer a rich source of data and of robust environment-evolution explanations that must be integrated into efforts by Earth scientists who seek to examine high-resolution climate records of human evolution. Paleoanthropological examples will illustrate the opportunities that exist for connecting evolutionary benchmarks to the data obtained from drilled African muds. Project members: R. Potts, A

African American Women’s Preparation for Childbirth From the Perspective of African American Health-Care Providers

PubMed Central

Abbyad, Christine; Robertson, Trina Reed

2011-01-01

Preparation for birthing has focused primarily on Caucasian women. No studies have explored African American women’s birth preparation. From the perceptions of 12 African American maternity health-care providers, this study elicited perceptions of the ways in which pregnant African American women prepare for childbirth. Focus group participants answered seven semistructured questions. Four themes emerged: connecting with nurturers, traversing an unresponsive system, the need to be strong, and childbirth classes not a priority. Recommendations for nurses and childbirth educators include: (a) self-awareness of attitudes toward African Americans, (b) empowering of clients for birthing, (c) recognition of the role that pregnant women’s mothers play, (d) tailoring of childbirth classes for African American women, and (e) research on how racism influences pregnant African American women’s preparation for birthing. PMID:22211059

Health and human rights a South African perspective.

PubMed

Naidoo, Sudeshni

2014-01-01

General statements of basic entitlements are established as a guide for potential laws and regulations protecting human rights. Human rights are those claimed to belong to every individual regardless of nationality or position within society. The historical evolution of human rights relative to health in the Republic of South Africa is discussed.

Diseases that turn African hair silky.

PubMed

Ajose, Frances O A

2012-11-01

African hair in its natural state poses tenacious grooming challenges; consequently a large portion of the African cosmetic industry is focused on means to relax the tight curls of African hair to make the hair more manageable. In malnourished and hypoproteinemic states, African hair straightens in an uncomplimentary manner. Recently, we observed that in certain diseases African hair changes to a desirable silky wavy texture. To identify the diseases that turn African hair silky and their parameters we examined 5612 dermatology patients at a tertiary hospital in Nigeria. We then studied the clinical and basic laboratory parameters of those patients whose diseases were accompanied by the silky hair change. Silky hair change similar to the hair of the African neonatal child was observed in five diseases, namely AIDS, rheumatoid arthritis, systemic lupus erythematosus, pulmonary tuberculosis with cachexia, and Behçet's disease. Our study identified retrogression of African hair to the neonatal structure in five diseases. Anemia of chronic illness, high erythrocyte sedimentation rate, and mild hypocalcemia were significant laboratory parameters. This is an important observation, which should excite and advance research into the nature and structure of African hair. The causes of structural hair changes should include these five diseases. © 2012 The International Society of Dermatology.

21st Century African Philosophy of Adult and Human Resource Education in Southern Africa

ERIC Educational Resources Information Center

Mutamba, Charlene

2012-01-01

This paper will attempt to define a philosophy of adult education for the purpose of workforce development in Southern Africa. The different influences such as Ubuntu and communalism, indigenous education, diversity western philosophy, globalization and technology are explored in the context of the Southern African region.

The Struggles over African Languages

ERIC Educational Resources Information Center

Maseko, Pam; Vale, Peter

2016-01-01

In this interview, African Language expert Pam Maseko speaks of her own background and her first encounter with culture outside of her mother tongue, isiXhosa. A statistical breakdown of South African languages is provided as background. She discusses Western (originally missionary) codification of African languages and suggests that this approach…

Lung cancer disparities and African-Americans.

PubMed

Sin, Mo-Kyung

2017-07-01

African-Americans, as historically disadvantaged minorities, have more advanced stages of cancer when diagnosed, lower survival rates, and lower rates of accessing timely care than do Caucasians. Lung cancer incidence and mortality, in particular, are high among African-Americans. The U.S. Preventive Services Task Force recently released an evidence-based lung cancer screening technology called low-dose computerized tomography. High-risk African-Americans might benefit greatly from such screening but not many are aware of this technology. Public health nurses can play a key role in increasing awareness of the technology among African-American communities and encouraging qualified African-Americans to obtain screening. This study discusses issues with lung cancer and smoking among African-Americans, a recently released evidence-based lung cancer screening technology, and implications for public health nurses to enhance uptake of the new screening technology among high-risk African-Americans. © 2017 Wiley Periodicals, Inc.

The North African Middle Stone Age and its place in recent human evolution.

PubMed

Scerri, Eleanor M L

2017-05-01

The North African Middle Stone Age (NAMSA, ∼300-24 thousand years ago, or ka) features what may be the oldest fossils of our species as well as extremely early examples of technological regionalization and 'symbolic' material culture (d'Errico, Vanhaeren, Barton, Bouzouggar, Mienis, Richter, Hublin, McPherron, Louzouet, & Klein, ; Scerri, ; Richter, Grün, Joannes-Boyau, Steele, Amani, Rué, Fernandes, Raynal, Geraads, Ben-Ncer Hublin, McPherron, ). The geographic situation of North Africa and an increased understanding of the wet-dry climatic pulses of the Sahara Desert also show that North Africa played a strategic role in continental-scale evolutionary processes by modulating human dispersal and demographic structure (Drake, Blench, Armitage, Bristow, & White, ; Blome, Cohen, Tryon, Brooks, & Russell, ). However, current understanding of the NAMSA remains patchy and subject to a bewildering array of industrial nomenclatures that mask underlying variability. These issues are compounded by a geographic research bias skewed toward non-desert regions. As a result, it has been difficult to test long-established narratives of behavioral and evolutionary change in North Africa and to resolve debates on their wider significance. In order to evaluate existing data and identify future research directions, this paper provides a critical overview of the component elements of the NAMSA and shows that the timing of many key behaviors has close parallels with others in sub-Saharan Africa and Southwest Asia. © 2017 Wiley Periodicals, Inc.

States of emergence: Writing African female same-sex sexuality.

PubMed

Munro, Brenna M

2017-04-03

Tracing a series of intertextually linked short stories from the 1990s to the present by women writers from Nigeria and its diaspora-Chimamanda Ngozi Adichie, Unoma Azuah, Chinelo Okparanta, and Lola Shoneyin-I suggest that although the figure of the African lesbian appears "new" in the context of heightened contemporary attention to the issue of homosexuality, this figure has a literary history. Ghanaian Ama Ata Aidoo's novel Our Sister Killjoy: Or, Reflections From A Black-Eyed Squint (1977) inaugurates this formation, in which the imagining of female same-sex desire is entangled with articulating the experience of migration under the shadow of imperial histories. In these short stories, the emphasis on the difficulties of love in puritanical times and transnational places produces the figure of the African lesbian as a symbol of appealingly human vulnerability, resilience, and complexity.

Unpacking rights in indigenous African societies: indigenous culture and the question of sexual and reproductive rights in Africa

PubMed Central

2011-01-01

Background Modern declarations on human rights have often proceeded without reference to the cultural content of rights, the existence of rights in African indigenous backgrounds, and the embodiment of certain key rights in the community itself. This paper is an attempt at developing an ‘inventory’ of rights in African cultures as a prelude to the generation both of a holistic theory of rights as well as a research agenda that can recognize the multifaceted nature of rights. Methods We use an interpretive ethnographic approach built on three sources of data: 1) our continuing ethnographic work among two distinct ethnic groups in southeastern Nigeria – the Ubang and the Igbo; 2) informal conversational interviews with individuals from a range of African countries; and 3) a review of relevant literature based on African cultures which provides a context for some of the issues we raise. Results An examination of selected indigenous rights, entitlements, or privileges among the Ubang and Igbo illustrates indigenous culture as a key, but often neglected, axis of rights, as a critical framework for understanding human relationships with rights, and as a resource for, and challenge to, contemporary programmatic efforts focusing on universalized notions of rights. Understanding or interpreting rights in African settings within the framework defined by contemporary human rights discourse poses steep challenges to making progress in the realization of sexual and reproductive rights. Conclusions Despite the potential dangers of privileging group rights over individual rights, when important rights are vested in the community; rights, entitlements, and privileges can also be recognized through community experiences, and realized through engagement with communities. Building on communal conceptualizations of rights in order to realize an even wider range of rights remains a largely unexplored strategy which holds promise for the achievement of sexual and reproductive

The Education of African-Americans.

ERIC Educational Resources Information Center

Willie, Charles V., Ed.; And Others

The 17 papers in this volume are products of a study group on the education of African Americans that was part of a national project, "The Assessment of the Status of African-Americans." The volume takes a comprehensive look at the education of African Americans, specifically early childhood through postsecondary education, and relevant…

Development Priorities for African Universities

ERIC Educational Resources Information Center

Baijnath, Narend; James, Genevieve

2015-01-01

African knowledge remains at best on the margins, struggling for an epistemological foothold in the face of an ever dominant Western canon. At worst, African knowledge is disparaged, depreciated, and dismissed. It is often ignored even by African scholars who, having gained control of the academy in the postcolonial context, seemingly remain…

Rapid changes in the gut microbiome during human evolution

PubMed Central

Moeller, Andrew H.; Li, Yingying; Mpoudi Ngole, Eitel; Ahuka-Mundeke, Steve; Lonsdorf, Elizabeth V.; Pusey, Anne E.; Peeters, Martine; Hahn, Beatrice H.; Ochman, Howard

2014-01-01

Humans are ecosystems containing trillions of microorganisms, but the evolutionary history of this microbiome is obscured by a lack of knowledge about microbiomes of African apes. We sequenced the gut communities of hundreds of chimpanzees, bonobos, and gorillas and developed a phylogenetic approach to reconstruct how present-day human microbiomes have diverged from those of ancestral populations. Compositional change in the microbiome was slow and clock-like during African ape diversification, but human microbiomes have deviated from the ancestral state at an accelerated rate. Relative to the microbiomes of wild apes, human microbiomes have lost ancestral microbial diversity while becoming specialized for animal-based diets. Individual wild apes cultivate more phyla, classes, orders, families, genera, and species of bacteria than do individual humans across a range of societies. These results indicate that humanity has experienced a depletion of the gut flora since diverging from Pan. PMID:25368157

Rapid changes in the gut microbiome during human evolution.

PubMed

Moeller, Andrew H; Li, Yingying; Mpoudi Ngole, Eitel; Ahuka-Mundeke, Steve; Lonsdorf, Elizabeth V; Pusey, Anne E; Peeters, Martine; Hahn, Beatrice H; Ochman, Howard

2014-11-18

Humans are ecosystems containing trillions of microorganisms, but the evolutionary history of this microbiome is obscured by a lack of knowledge about microbiomes of African apes. We sequenced the gut communities of hundreds of chimpanzees, bonobos, and gorillas and developed a phylogenetic approach to reconstruct how present-day human microbiomes have diverged from those of ancestral populations. Compositional change in the microbiome was slow and clock-like during African ape diversification, but human microbiomes have deviated from the ancestral state at an accelerated rate. Relative to the microbiomes of wild apes, human microbiomes have lost ancestral microbial diversity while becoming specialized for animal-based diets. Individual wild apes cultivate more phyla, classes, orders, families, genera, and species of bacteria than do individual humans across a range of societies. These results indicate that humanity has experienced a depletion of the gut flora since diverging from Pan.

Globin haplotypes of human T-cell lymphotropic virus type I-infected individuals in Salvador, Bahia, Brazil, suggest a post-Columbian African origin of this virus.

PubMed

Alcantara, Luiz Carlos; Van Dooren, Sonia; Gonçalves, Marilda Souza; Kashima, Simone; Costa, Maria Cristina Ramos; Santos, Fred Luciano Neves; Bittencourt, Achilea Lisboa; Dourado, Inês; Filho, Antonio Andrade; Covas, Dimas Tadeu; Vandamme, Anne-Mieke; Galvão-Castro, Bernardo

2003-08-01

The city of Salvador, Bahia, Brazil, has sociodemographic characteristics similar to some African cities. Up to now, it has had the highest prevalence of human T-cell lymphotropic virus type I (HTLV-I) infection (1.74%) in the country. To investigate which strains of HTLV-I are circulating in Salvador, we studied isolates from 82 patients infected with HTLV-I: 19 from the general population, 21 from pregnant women, 16 from intravenous drug users, and 26 from patients and their family attending a neurologic clinic. Phylogenetic analysis from part of the LTR fragments showed that most of these isolates belonged to the Transcontinental subgroup of the Cosmopolitan subtype (HTLV-Ia). Only one sample from a pregnant woman was closely related to the Japanese subgroup, suggesting recent introduction of a Japanese HTLV-I lineage into Salvador. betaA-Globin haplotypes were examined in 34 infected individuals and found to be atypical, confirming the racial heterogeneity of this population. A total of 20 chromosomes were characterized as Central African Republic (CAR) haplotype (29.4%), 31 (45.6%) were characterized as Benin (BEN) haplotype, and 17 (25%) were characterized as Senegal (SEN) haplotype. Five patients' genotypes (14.7%) were CAR/CAR; 10 (29,4%), BEN/BEN; 9 (26.5%), CAR/BEN; 2 (5.9%), BEN/SEN; and 7 (20.6%), SEN/SEN. One patient's genotype (2.9%) was CAR/SEN. The betaA-globin haplotype distribution in Salvador is unusual compared with other Brazilian states. Our data support the hypothesis of multiple post-Columbian introductions of African HTLV-Ia strains in Salvador, Bahia, Brazil.

The Atlas of human African trypanosomiasis: a contribution to global mapping of neglected tropical diseases

PubMed Central

2010-01-01

Background Following World Health Assembly resolutions 50.36 in 1997 and 56.7 in 2003, the World Health Organization (WHO) committed itself to supporting human African trypanosomiasis (HAT)-endemic countries in their efforts to remove the disease as a public health problem. Mapping the distribution of HAT in time and space has a pivotal role to play if this objective is to be met. For this reason WHO launched the HAT Atlas initiative, jointly implemented with the Food and Agriculture Organization of the United Nations, in the framework of the Programme Against African Trypanosomosis. Results The distribution of HAT is presented for 23 out of 25 sub-Saharan countries having reported on the status of sleeping sickness in the period 2000 - 2009. For the two remaining countries, i.e. Angola and the Democratic Republic of the Congo, data processing is ongoing. Reports by National Sleeping Sickness Control Programmes (NSSCPs), Non-Governmental Organizations (NGOs) and Research Institutes were collated and the relevant epidemiological data were entered in a database, thus incorporating (i) the results of active screening of over 2.2 million people, and (ii) cases detected in health care facilities engaged in passive surveillance. A total of over 42 000 cases of HAT and 6 000 different localities were included in the database. Various sources of geographic coordinates were used to locate the villages of epidemiological interest. The resulting average mapping accuracy is estimated at 900 m. Conclusions Full involvement of NSSCPs, NGOs and Research Institutes in building the Atlas of HAT contributes to the efficiency of the mapping process and it assures both the quality of the collated information and the accuracy of the outputs. Although efforts are still needed to reduce the number of undetected and unreported cases, the comprehensive, village-level mapping of HAT control activities over a ten-year period ensures a detailed and reliable representation of the known

Gout in African Americans.

PubMed

Krishnan, Eswar

2014-09-01

African Americans have a substantially higher prevalence of risk factors for gout than Caucasians. The aim of the present study was to compare the risk for incident gout among African Americans and Caucasians. Incidence rates of physician-diagnosed gout among 11,559 Caucasian men and 931 African American men aged 35 to 57 years and at high cardiovascular risk, observed for 7 years as a part of the Multiple Risk Factor Intervention Trial, were analyzed. Cox regression models were used to account for potential confounding by age, body mass index, diuretic use, hypertension and diabetes status, aspirin and alcohol consumption, and kidney disease. At baseline, after accounting for risk factors, African Americans had a 14% lower prevalence of hyperuricemia than Caucasians. Incidence of gout increased with increasing prevalence of risk factors in both Caucasians and African Americans. Ethnic disparities in incidence rates were most apparent among those without other risk factors for gout. In separate Cox regression models, after accounting for risk factors, African American ethnicity was associated with a hazard ratio of 0.78 (95% confidence interval [CI], 0.66-0.93) for physician-diagnosed gout and 0.88 (95% CI, 0.85-0.90) for incident hyperuricemia. Significant interactions were observed; the association was the strongest (hazard ratio 0.47; 0.37-0.60). These associations were unaffected by addition of serum urate as a covariate or by using alternate case definitions for gout. After accounting for the higher prevalence of risk factors, African American ethnicity is associated with a significantly lower risk for gout and hyperuricemia compared with Caucasian ethnicity. Copyright © 2014 Elsevier Inc. All rights reserved.

Measuring human rights violations in a conflict-affected country: results from a nationwide cluster survey in Central African Republic.

PubMed

Potts, Alina; Myer, Kathleen; Roberts, Les

2011-03-07

Measuring human rights violations is particularly challenging during or after armed conflict. A recent nationwide survey in the Central African Republic produced estimates of rates of grave violations against children and adults affected by armed conflict, using an approach known as the "Neighborhood Method". In June and July, 2009, a random household survey was conducted based on population estimates from the 2003 national census. Clusters were assigned systematically proportional to population size. Respondents in randomly selected households were interviewed regarding incidents of killing, intentional injury, recruitment into armed groups, abduction, sexual abuse and rape between January 1, 2008 and the date of interview, occurring in their homes' and those of their three closest neighbors. Sixty of the selected 69 clusters were surveyed. In total, 599 women were interviewed about events in 2,370 households representing 13,669 persons. Estimates of annual rates of each violation occurring per 1000 people in each of two strata are provided for children between the ages of five and 17, adults 18 years of age and older and the entire population five years and older, along with a combined and weighted national rate. The national rates for children age five to 17 were estimated to be 0.98/1000/year (95% CI: 0.18 - 1.78) for recruitment, 2.56/1000/year (95% CI: 1.50 - 3.62) for abduction, 1.13/1000/year (95% CI: 0.33 - 1.93) for intentional injury, 10.72/1000 girls/year (95% CI: 7.40 - 14.04) for rape, and 4.80/1000 girls/year (95% CI: 2.61 - 6.00) for sexual abuse. No reports of any violation against a person under the age of five were recorded and there were no reports of rape or sexual abuse of males. No children were reported to have been killed during the recall period. Rape and abduction were the most frequently reported events. The population-based figures greatly augment existing information on human rights violations in CAR, and represent a step forward in

Narcolepsy in African Americans

PubMed Central

Kawai, Makoto; O'Hara, Ruth; Einen, Mali; Lin, Ling; Mignot, Emmanuel

2015-01-01

Study Objectives: Although narcolepsy affects 0.02–0.05% of individuals in various ethnic groups, clinical presentation in different ethnicities has never been fully characterized. Our goal was to study phenotypic expression across ethnicities in the United States. Design/Setting: Cases of narcolepsy from 1992 to 2013 were identified from searches of the Stanford Center for Narcolepsy Research database. International Classification of Sleep Disorders, Third Edition diagnosis criteria for type 1 and type 2 narcolepsy were used for inclusion, but subjects were separated as with and without cataplexy for the purpose of data presentation. Information extracted included demographics, ethnicity and clinical data, HLA-DQB1*06:02, polysomnography (PSG), multiple sleep latency test (MSLT) data, and cerebrospinal fluid (CSF) hypocretin-1 level. Patients: 182 African-Americans, 839 Caucasians, 35 Asians, and 41 Latinos with narcolepsy. Results: Sex ratio, PSG, and MSLT findings did not differ across ethnicities. Epworth Sleepiness Scale (ESS) score was higher and age of onset of sleepiness earlier in African Americans compared with other ethnicities. HLA-DQB1*06:02 positivity was higher in African Americans (91.0%) versus others (76.6% in Caucasians, 80.0% in Asians, and 65.0% in Latinos). CSF hypocretin-1 level, obtained in 222 patients, was more frequently low (≤ 110 pg/ml) in African Americans (93.9%) versus Caucasians (61.5%), Asians (85.7%) and Latinos (75.0%). In subjects with low CSF hypocretin-1, African Americans (28.3%) were 4.5 fold more likely to be without cataplexy when compared with Caucasians (8.1%). Conclusions: Narcolepsy in African Americans is characterized by earlier symptom onset, higher Epworth Sleepiness Scale score, higher HLA-DQB1*06:02 positivity, and low cerebrospinal fluid hypocretin-1 level in the absence of cataplexy. In African Americans, more subjects without cataplexy have type 1 narcolepsy. Citation: Kawai M, O'Hara R, Einen M, Lin L

A revised timescale for human evolution based on ancient mitochondrial genomes

PubMed Central

Johnson, Philip L.F.; Bos, Kirsten; Lari, Martina; Bollongino, Ruth; Sun, Chengkai; Giemsch, Liane; Schmitz, Ralf; Burger, Joachim; Ronchitelli, Anna Maria; Martini, Fabio; Cremonesi, Renata G.; Svoboda, Jiří; Bauer, Peter; Caramelli, David; Castellano, Sergi; Reich, David; Pääbo, Svante; Krause, Johannes

2016-01-01

Summary Background Recent analyses of de novo DNA mutations in modern humans have suggested a nuclear substitution rate that is approximately half that of previous estimates based on fossil calibration. This result has led to suggestions that major events in human evolution occurred far earlier than previously thought. Result Here we use mitochondrial genome sequences from 10 securely dated ancient modern humans spanning 40,000 years as calibration points for the mitochondrial clock, thus yielding a direct estimate of the mitochondrial substitution rate. Our clock yields mitochondrial divergence times that are in agreement with earlier estimates based on calibration points derived from either fossils or archaeological material. In particular, our results imply a separation of non-Africans from the most closely related sub-Saharan African mitochondrial DNAs (haplogroup L3) of less than 62,000-95,000 years ago. Conclusion Though single loci like mitochondrial DNA (mtDNA) can only provide biased estimates of population split times, they can provide valid upper bounds; our results exclude most of the older dates for African and non-African split times recently suggested by de novo mutation rate estimates in the nuclear genome. PMID:23523248

A revised timescale for human evolution based on ancient mitochondrial genomes.

PubMed

Fu, Qiaomei; Mittnik, Alissa; Johnson, Philip L F; Bos, Kirsten; Lari, Martina; Bollongino, Ruth; Sun, Chengkai; Giemsch, Liane; Schmitz, Ralf; Burger, Joachim; Ronchitelli, Anna Maria; Martini, Fabio; Cremonesi, Renata G; Svoboda, Jiří; Bauer, Peter; Caramelli, David; Castellano, Sergi; Reich, David; Pääbo, Svante; Krause, Johannes

2013-04-08

Recent analyses of de novo DNA mutations in modern humans have suggested a nuclear substitution rate that is approximately half that of previous estimates based on fossil calibration. This result has led to suggestions that major events in human evolution occurred far earlier than previously thought. Here, we use mitochondrial genome sequences from ten securely dated ancient modern humans spanning 40,000 years as calibration points for the mitochondrial clock, thus yielding a direct estimate of the mitochondrial substitution rate. Our clock yields mitochondrial divergence times that are in agreement with earlier estimates based on calibration points derived from either fossils or archaeological material. In particular, our results imply a separation of non-Africans from the most closely related sub-Saharan African mitochondrial DNAs (haplogroup L3) that occurred less than 62-95 kya. Though single loci like mitochondrial DNA (mtDNA) can only provide biased estimates of population divergence times, they can provide valid upper bounds. Our results exclude most of the older dates for African and non-African population divergences recently suggested by de novo mutation rate estimates in the nuclear genome. Copyright © 2013 Elsevier Ltd. All rights reserved.

The past, present and future of African dust.

PubMed

Evan, Amato T; Flamant, Cyrille; Gaetani, Marco; Guichard, Françoise

2016-03-24

African dust emission and transport exhibits variability on diurnal to decadal timescales and is known to influence processes such as Amazon productivity, Atlantic climate modes, regional atmospheric composition and radiative balance and precipitation in the Sahel. To elucidate the role of African dust in the climate system, it is necessary to understand the factors governing its emission and transport. However, African dust is correlated with seemingly disparate atmospheric phenomena, including the El Niño/Southern Oscillation, the North Atlantic Oscillation, the meridional position of the intertropical convergence zone, Sahelian rainfall and surface temperatures over the Sahara Desert, all of which obfuscate the connection between dust and climate. Here we show that the surface wind field responsible for most of the variability in North African dust emission reflects the topography of the Sahara, owing to orographic acceleration of the surface flow. As such, the correlations between dust and various climate phenomena probably arise from the projection of the winds associated with these phenomena onto an orographically controlled pattern of wind variability. A 161-year time series of dust from 1851 to 2011, created by projecting this wind field pattern onto surface winds from a historical reanalysis, suggests that the highest concentrations of dust occurred from the 1910s to the 1940s and the 1970s to the 1980s, and that there have been three periods of persistent anomalously low dust concentrations--in the 1860s, 1950s and 2000s. Projections of the wind pattern onto climate models give a statistically significant downward trend in African dust emission and transport as greenhouse gas concentrations increase over the twenty-first century, potentially associated with a slow-down of the tropical circulation. Such a dust feedback, which is not represented in climate models, may be of benefit to human and ecosystem health in West Africa via improved air quality and

What girls won't do for love: human immunodeficiency virus/sexually transmitted infections risk among young African-American women driven by a relationship imperative.

PubMed

Raiford, Jerris L; Seth, Puja; DiClemente, Ralph J

2013-05-01

Rates of Human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs) continue to increase among African-American youth. Adolescents who have a stronger identity in relation to others (relational identity) rather than to themselves (self-identity) may view intimate relationships as imperative to a positive self-concept, which may lead to risky sexual behavior and abuse. Therefore, the present study assessed the associations among a relationship imperative and HIV/STI-related risk factors and behaviors. Participants were 715 African-American adolescent females, aged 15 to 21 years. They completed measures that assessed how important a relationship was to them and HIV-related risk factors and behaviors. Participants also provided vaginal swab specimens for STI testing. Multivariate logistic regression analyses, controlling for covariates, were conducted. Females who endorsed a relationship imperative (29%), compared to those who did not, were more likely to report: unprotected sex, less power in their relationships, perceived inability to refuse sex, anal sex, sex while their partner was high on alcohol/drugs, and partner abuse. Furthermore, participants with less power, recent partner abuse, and a perceived ability to refuse sex were more likely to test STI positive. These results indicate that if African-American adolescent females believe a relationship is imperative, they are more likely to engage in riskier sexual behaviors. Additionally, less perceived power and partner abuse increases their risk for STIs. HIV/STI prevention programs should target males and females and address healthy relationships, sense of self-worth, self-esteem and the gender power imbalance that may persist in the community along with HIV/STI risk. Published by Elsevier Inc.

South African-ness Among Adolescents: The Emergence of a Collective Identity within the Birth to Twenty Cohort Study

PubMed Central

Norris, Shane A; Roeser, Robert W.; Richter, Linda M; Lewin, Nina; Ginsburg, Carren; Fleetwood, Stella A; Taole, Elizabeth; van der Wolf, Kees

2009-01-01

We assessed the emergence of a South African identity among Black, Colored (mixed ancestral origin), White (predominantly English speaking), and Indian adolescents participating in a birth cohort study called “Birth to Twenty” in Johannesburg, South Africa. We examined young people's certainty of their self-categorization as South African, the centrality of their personal, racial and linguistic, and South African identities in their self-definition, and their perceptions of South African life and society today. These results reflect a historical opportunity for full citizenship and national enfranchisement that the end of Apartheid heralded for Black and Colored individuals. Black and Colored youth tend to be more certain about their South African-ness, have a more collective identity, and have a more positive perception around South Africa. In contrast, White and Indian youth are less certain about their South African-ness, have a more individualistic identity, and have a less positive perception about South Africa today. PMID:19461896

Attenuated Human Parainfluenza Virus Type 1 Expressing Ebola Virus Glycoprotein GP Administered Intranasally Is Immunogenic in African Green Monkeys.

PubMed

Lingemann, Matthias; Liu, Xueqiao; Surman, Sonja; Liang, Bo; Herbert, Richard; Hackenberg, Ashley D; Buchholz, Ursula J; Collins, Peter L; Munir, Shirin

2017-05-15

The recent 2014-2016 Ebola virus (EBOV) outbreak prompted increased efforts to develop vaccines against EBOV disease. We describe the development and preclinical evaluation of an attenuated recombinant human parainfluenza virus type 1 (rHPIV1) expressing the membrane-anchored form of EBOV glycoprotein GP, as an intranasal (i.n.) EBOV vaccine. GP was codon optimized and expressed either as a full-length protein or as an engineered chimeric form in which its transmembrane and cytoplasmic tail (TMCT) domains were replaced with those of the HPIV1 F protein in an effort to enhance packaging into the vector particle and immunogenicity. GP was inserted either preceding the N gene (pre-N) or between the N and P genes (N-P) of rHPIV1 bearing a stabilized attenuating mutation in the P/C gene (C Δ170 ). The constructs grew to high titers and efficiently and stably expressed GP. Viruses were attenuated, replicating at low titers over several days, in the respiratory tract of African green monkeys (AGMs). Two doses of candidates expressing GP from the pre-N position elicited higher GP neutralizing serum antibody titers than the N-P viruses, and unmodified GP induced higher levels than its TMCT counterpart. Unmodified EBOV GP was packaged into the HPIV1 particle, and the TMCT modification did not increase packaging or immunogenicity but rather reduced the stability of GP expression during in vivo replication. In conclusion, we identified an attenuated and immunogenic i.n. vaccine candidate expressing GP from the pre-N position. It is expected to be well tolerated in humans and is available for clinical evaluation. IMPORTANCE EBOV hemorrhagic fever is one of the most lethal viral infections and lacks a licensed vaccine. Contact of fluids from infected individuals, including droplets or aerosols, with mucosal surfaces is an important route of EBOV spread during a natural outbreak, and aerosols also might be exploited for intentional virus spread. Therefore, vaccines that protect

African-Americans and Alzheimer's

MedlinePlus

... Share Plus on Google Plus African-Americans and Alzheimer's alz.org | IHaveAlz Introduction 10 Warning Signs Brain ... African-Americans are at a higher risk for Alzheimer's disease. Many Americans dismiss the warning signs of ...

Liberalism and African Culture.

ERIC Educational Resources Information Center

Sindima, Harvey

1990-01-01

Discusses the effect of liberalism on the African understanding of education, community, and religion. Describes ways in which the European intrusion, that is, colonial governments, schools, and churches, undermined traditional African life and thought. (DM)

Solar-powered ventilation of African termite mounds.

PubMed

Ocko, Samuel A; King, Hunter; Andreen, David; Bardunias, Paul; Turner, J Scott; Soar, Rupert; Mahadevan, L

2017-09-15

How termite mounds function to facilitate climate control is still only partially understood. Recent experimental evidence in the mounds of a single species, the south Asian termite Odontotermes obesus , suggests that the daily oscillations of radiant heating associated with diurnal insolation patterns drive convective flow within them. How general this mechanism is remains unknown. To probe this, we consider the mounds of the African termite Macrotermes michaelseni , which thrives in a very different environment. By directly measuring air velocities and temperatures within the mound, we see that the overall mechanisms and patterns involved are similar to that in the south Asian species. However, there are also some notable differences between the physiology of these mounds associated with the temporal variations in radiant heating patterns and CO 2 dynamics. Because of the difference between direct radiant heating driven by the position of the sun in African conditions, and the more shaded south Asian environments, we see changes in the convective flows in the two types of mounds. Furthermore, we also see that the south Asian mounds show a significant overturning of stratified gases, once a day, while the African mounds have a relatively uniform concentration of CO 2 Overall, our observations show that despite these differences, termite architectures can harness periodic solar heating to drive ventilation inside them in very different environments, functioning as an external lung, with clear implications for human engineering. © 2017. Published by The Company of Biologists Ltd.

An African Ancestry-Specific Allele of CTLA4 Confers Protection against Rheumatoid Arthritis in African Americans

PubMed Central

Kelley, James M.; Hughes, Laura B.; Faggard, Jeffrey D.; Danila, Maria I.; Crawford, Monica H.; Edberg, Yuanqing; Padilla, Miguel A.; Tiwari, Hemant K.; Westfall, Andrew O.; Alarcón, Graciela S.; Conn, Doyt L.; Jonas, Beth L.; Callahan, Leigh F.; Smith, Edwin A.; Brasington, Richard D.; Allison, David B.; Kimberly, Robert P.; Moreland, Larry W.; Edberg, Jeffrey C.; Bridges, S. Louis

2009-01-01

Cytotoxic T-lymphocyte associated protein 4 (CTLA4) is a negative regulator of T-cell proliferation. Polymorphisms in CTLA4 have been inconsistently associated with susceptibility to rheumatoid arthritis (RA) in populations of European ancestry but have not been examined in African Americans. The prevalence of RA in most populations of European and Asian ancestry is ∼1.0%; RA is purportedly less common in black Africans, with little known about its prevalence in African Americans. We sought to determine if CTLA4 polymorphisms are associated with RA in African Americans. We performed a 2-stage analysis of 12 haplotype tagging single nucleotide polymorphisms (SNPs) across CTLA4 in a total of 505 African American RA patients and 712 African American controls using Illumina and TaqMan platforms. The minor allele (G) of the rs231778 SNP was 0.054 in RA patients, compared to 0.209 in controls (4.462×10−26, Fisher's exact). The presence of the G allele was associated with a substantially reduced odds ratio (OR) of having RA (AG+GG genotypes vs. AA genotype, OR 0.19, 95% CI: 0.13–0.26, p = 2.4×10−28, Fisher's exact), suggesting a protective effect. This SNP is polymorphic in the African population (minor allele frequency [MAF] 0.09 in the Yoruba population), but is very rare in other groups (MAF = 0.002 in 530 Caucasians genotyped for this study). Markers associated with RA in populations of European ancestry (rs3087243 [+60C/T] and rs231775 [+49A/G]) were not replicated in African Americans. We found no confounding of association for rs231778 after stratifying for the HLA-DRB1 shared epitope, presence of anti-cyclic citrullinated peptide antibody, or degree of admixture from the European population. An African ancestry-specific genetic variant of CTLA4 appears to be associated with protection from RA in African Americans. This finding may explain, in part, the relatively low prevalence of RA in black African populations. PMID:19300490

The Golden Lady: The Storied Life of a Multilingual Teacher and Author of Supplemental Reading Materials in a Marginalized South African Language

ERIC Educational Resources Information Center

Horan, Deborah A.; Sailors, Misty; Martinez, Miriam; Skerrett, Allison; Makalela, Leketi

2012-01-01

Personal narratives can be powerful venues for understanding human experiences. In this paper, we tell the story of Lutanyani, a Black South African multilingual teacher and author of supplemental reading materials in a marginalized South African language. Through various word images, we convey the role of language, in particular written language,…

The African Lithosphere

NASA Astrophysics Data System (ADS)

Priestley, K.; Debayle, E.; McKenzie, D.; Pilidou, S.

2007-12-01

There have been a number of prior, large scale surface wave studies of Africa, the majority of which rely on fundamental mode observations. In this study we use a large data set of multi-mode surface waves recorded over epicentral distances most of which are shorter than 6000 km, to investigate the Sv wave speed heterogeneity of the upper mantle beneath Africa. The inclusion of the higher mode data allow us to build an upper mantle model for the African plate with a horizontal resolution of a few hundred kilometers and a vertical resolution of a few tens of kilometers extending to about 400 km depth. Our tomographic images of the upper mantle beneath Africa displays significant shear velocity features, much of which correlate with surface geology. High velocity mantle persists beneath the West African and Congo cratons to 225-250 km depth, but the high velocity root beneath Kalahari Craton extends to only about 175 km depth. Low velocity upper mantle underlies the Pan- African terranes of Africa with the exception of the Damara mobile belt separating the Congo and Kalahari Cratons. The Damara mobile belt is underlain by a thick high velocity upper mantle lid which is indistinguishable from that beneath the Congo Craton to the north and the Kalahari Craton to the south. Low velocity upper mantle underlie the Hoggar, Tebesti and Darfur volcanic areas of northern Africa, and very low velocities underlie the Afar region to at least 400 km depth. We use the relationship between shear velocity and temperature of Priestley & McKenzie (2006) to derive a model for the African thermal lithosphere. Two types of lithosphere underlie Africa. Thick lithosphere underlies most of western Africa and all of southern Africa; in the latter the extent of the thick lithosphere is significantly different from the distribution of Archean crust mapped at the surface. Thick lithosphere forms one continuous structure beneath the Congo and Kalahari Cratons. Other than the Pan-African Damara

Molecular Comparison and Evolutionary Analyses of VP1 Nucleotide Sequences of New African Human Enterovirus 71 Isolates Reveal a Wide Genetic Diversity

PubMed Central

Nougairède, Antoine; Joffret, Marie-Line; Deshpande, Jagadish M.; Dubot-Pérès, Audrey; Héraud, Jean-Michel

2014-01-01

Most circulating strains of Human enterovirus 71 (EV-A71) have been classified primarily into three genogroups (A to C) on the basis of genetic divergence between the 1D gene, which encodes the VP1 capsid protein. The aim of the present study was to provide further insights into the diversity of the EV-A71 genogroups following the recent description of highly divergent isolates, in particular those from African countries, including Madagascar. We classified recent EV-A71 isolates by a large comparison of 3,346 VP1 nucleotidic sequences collected from GenBank. Analysis of genetic distances and phylogenetic investigations indicated that some recently-reported isolates did not fall into the genogroups A-C and clustered into three additional genogroups, including one Indian genogroup (genogroup D) and 2 African ones (E and F). Our Bayesian phylogenetic analysis provided consistent data showing that the genogroup D isolates share a recent common ancestor with the members of genogroup E, while the isolates of genogroup F evolved from a recent common ancestor shared with the members of the genogroup B. Our results reveal the wide diversity that exists among EV-A71 isolates and suggest that the number of circulating genogroups is probably underestimated, particularly in developing countries where EV-A71 epidemiology has been poorly studied. PMID:24598878

The genetics of East African populations: a Nilo-Saharan component in the African genetic landscape

PubMed Central

Dobon, Begoña; Hassan, Hisham Y.; Laayouni, Hafid; Luisi, Pierre; Ricaño-Ponce, Isis; Zhernakova, Alexandra; Wijmenga, Cisca; Tahir, Hanan; Comas, David; Netea, Mihai G.; Bertranpetit, Jaume

2015-01-01

East Africa is a strategic region to study human genetic diversity due to the presence of ethnically, linguistically, and geographically diverse populations. Here, we provide new insight into the genetic history of populations living in the Sudanese region of East Africa by analysing nine ethnic groups belonging to three African linguistic families: Niger-Kordofanian, Nilo-Saharan and Afro-Asiatic. A total of 500 individuals were genotyped for 200,000 single-nucleotide polymorphisms. Principal component analysis, clustering analysis using ADMIXTURE, FST statistics, and the three-population test were used to investigate the underlying genetic structure and ancestry of the different ethno-linguistic groups. Our analyses revealed a genetic component for Sudanese Nilo-Saharan speaking groups (Darfurians and part of Nuba populations) related to Nilotes of South Sudan, but not to other Sudanese populations or other sub-Saharan populations. Populations inhabiting the North of the region showed close genetic affinities with North Africa, with a component that could be remnant of North Africans before the migrations of Arabs from Arabia. In addition, we found very low genetic distances between populations in genes important for anti-malarial and anti-bacterial host defence, suggesting similar selective pressures on these genes and stressing the importance of considering functional pathways to understand the evolutionary history of populations. PMID:26017457

Development and characterization of microsatellite markers in the African forest elephant (Loxodonta cyclotis).

PubMed

Gugala, Natalie A; Ishida, Yasuko; Georgiadis, Nicholas J; Roca, Alfred L

2016-07-26

African elephants comprise two species, the savanna elephant (Loxodonta africana) and the forest elephant (L. cyclotis), which are distinct morphologically and genetically. Forest elephants are seriously threatened by poaching for meat and ivory, and by habitat destruction. However, microsatellite markers have thus far been developed only in African savanna elephants and Asian elephants, Elephas maximus. The application of microsatellite markers across deeply divergent lineages may produce irregular patterns such as large indels or null alleles. Thus we developed novel microsatellite markers using DNA from two African forest elephants. One hundred microsatellite loci were identified in next generation shotgun sequences from two African forest elephants, of which 53 were considered suitable for testing. Twenty-three microsatellite markers successfully amplified elephant DNA without amplifying human DNA; these were further characterized in 15 individuals from Lope National Park, Gabon. Three of the markers were monomorphic and four of them carried only two alleles. The remaining sixteen polymorphic loci carried from 3 to 8 alleles, with observed heterozygosity ranging from 0.27 to 0.87, expected heterozygosity from 0.40 to 0.86, and the Shannon diversity index from 0.73 to 1.86. Linkage disequilibrium was not detected between loci, and no locus deviated from Hardy-Weinberg equilibrium. The markers developed in this study will be useful for genetic analyses of the African forest elephant and contribute to their conservation and management.

Direct Blood Dry LAMP: A Rapid, Stable, and Easy Diagnostic Tool for Human African Trypanosomiasis

PubMed Central

Hayashida, Kyoko; Kajino, Kiichi; Hachaambwa, Lottie; Namangala, Boniface; Sugimoto, Chihiro

2015-01-01

Loop-mediated isothermal amplification (LAMP) is a rapid and sensitive tool used for the diagnosis of a variety of infectious diseases. One of the advantages of this method over the polymerase chain reaction is that DNA amplification occurs at a constant temperature, usually between 60–65°C; therefore, expensive devices are unnecessary for this step. However, LAMP still requires complicated sample preparation steps and a well-equipped laboratory to produce reliable and reproducible results, which limits its use in resource-poor laboratories in most developing countries. In this study, we made several substantial modifications to the technique to carry out on-site diagnosis of Human African Trypanosomiasis (HAT) in remote areas using LAMP. The first essential improvement was that LAMP reagents were dried and stabilized in a single tube by incorporating trehalose as a cryoprotectant to prolong shelf life at ambient temperature. The second technical improvement was achieved by simplifying the sample preparation step so that DNA or RNA could be amplified directly from detergent-lysed blood samples. With these modifications, diagnosis of HAT in local clinics or villages in endemic areas becomes a reality, which could greatly impact on the application of diagnosis not only for HAT but also for other tropical diseases. PMID:25769046

Constitutional Values and Human Dignity: Its Value in Education

ERIC Educational Resources Information Center

Bray, Elmene

2004-01-01

Human dignity is intrinsic to every human being and is universally recognised as a fundamental right. Under a previous oppressive system, most South Africans had been denied basic human rights, including the right to human dignity. The constitutional negotiations of the 1990s abolished the apartheid system and constituted a sovereign democratic…

Human and Helicobacter pylori coevolution shapes the risk of gastric disease.

PubMed

Kodaman, Nuri; Pazos, Alvaro; Schneider, Barbara G; Piazuelo, M Blanca; Mera, Robertino; Sobota, Rafal S; Sicinschi, Liviu A; Shaffer, Carrie L; Romero-Gallo, Judith; de Sablet, Thibaut; Harder, Reed H; Bravo, Luis E; Peek, Richard M; Wilson, Keith T; Cover, Timothy L; Williams, Scott M; Correa, Pelayo

2014-01-28

Helicobacter pylori is the principal cause of gastric cancer, the second leading cause of cancer mortality worldwide. However, H. pylori prevalence generally does not predict cancer incidence. To determine whether coevolution between host and pathogen influences disease risk, we examined the association between the severity of gastric lesions and patterns of genomic variation in matched human and H. pylori samples. Patients were recruited from two geographically distinct Colombian populations with significantly different incidences of gastric cancer, but virtually identical prevalence of H. pylori infection. All H. pylori isolates contained the genetic signatures of multiple ancestries, with an ancestral African cluster predominating in a low-risk, coastal population and a European cluster in a high-risk, mountain population. The human ancestry of the biopsied individuals also varied with geography, with mostly African ancestry in the coastal region (58%), and mostly Amerindian ancestry in the mountain region (67%). The interaction between the host and pathogen ancestries completely accounted for the difference in the severity of gastric lesions in the two regions of Colombia. In particular, African H. pylori ancestry was relatively benign in humans of African ancestry but was deleterious in individuals with substantial Amerindian ancestry. Thus, coevolution likely modulated disease risk, and the disruption of coevolved human and H. pylori genomes can explain the high incidence of gastric disease in the mountain population.

Selective breeding: the future of TB management in African buffalo?

PubMed

le Roex, N; Berrington, C M; Hoal, E G; van Helden, P D

2015-09-01

The high prevalence of bovine tuberculosis (BTB) in African buffalo (Syncerus caffer) in regions of southern African has a negative economic impact on the trade of animals and animal products, represents an ecological threat to biodiversity, and poses a health risk to local communities through the wildlife-cattle-human interface. Test and cull methods may not be logistically feasible in many free-range wildlife systems, and with the presence of co-existing BTB hosts and the limited effectiveness of the BCG vaccine in buffalo, there is a need for alternative methods of BTB management. Selective breeding for increased resistance to BTB in buffalo may be a viable method of BTB management in the future, particularly if genetic information can be incorporated into these schemes. To explore this possibility, we discuss the different strategies that can be employed in selective breeding programmes, and consider the implementation of genetic improvement schemes. We reflect on the suitability of applying this strategy for enhanced BTB resistance in African buffalo, and address the challenges of this approach that must be taken into account. Conclusions and the implications for management are presented. Copyright © 2015 Elsevier B.V. All rights reserved.

Narcolepsy in African Americans.

PubMed

Kawai, Makoto; O'Hara, Ruth; Einen, Mali; Lin, Ling; Mignot, Emmanuel

2015-11-01

Although narcolepsy affects 0.02-0.05% of individuals in various ethnic groups, clinical presentation in different ethnicities has never been fully characterized. Our goal was to study phenotypic expression across ethnicities in the United States. Cases of narcolepsy from 1992 to 2013 were identified from searches of the Stanford Center for Narcolepsy Research database. International Classification of Sleep Disorders, Third Edition diagnosis criteria for type 1 and type 2 narcolepsy were used for inclusion, but subjects were separated as with and without cataplexy for the purpose of data presentation. Information extracted included demographics, ethnicity and clinical data, HLA-DQB1*06:02, polysomnography (PSG), multiple sleep latency test (MSLT) data, and cerebrospinal fluid (CSF) hypocretin-1 level. 182 African-Americans, 839 Caucasians, 35 Asians, and 41 Latinos with narcolepsy. Sex ratio, PSG, and MSLT findings did not differ across ethnicities. Epworth Sleepiness Scale (ESS) score was higher and age of onset of sleepiness earlier in African Americans compared with other ethnicities. HLA-DQB1*06:02 positivity was higher in African Americans (91.0%) versus others (76.6% in Caucasians, 80.0% in Asians, and 65.0% in Latinos). CSF hypocretin-1 level, obtained in 222 patients, was more frequently low (≤ 110 pg/ml) in African Americans (93.9%) versus Caucasians (61.5%), Asians (85.7%) and Latinos (75.0%). In subjects with low CSF hypocretin-1, African Americans (28.3%) were 4.5 fold more likely to be without cataplexy when compared with Caucasians (8.1%). Narcolepsy in African Americans is characterized by earlier symptom onset, higher Epworth Sleepiness Scale score, higher HLA-DQB1*06:02 positivity, and low cerebrospinal fluid hypocretin-1 level in the absence of cataplexy. In African Americans, more subjects without cataplexy have type 1 narcolepsy. © 2015 Associated Professional Sleep Societies, LLC.

African-American Academic Nurse Leader's Role in Persistence of African-American Baccalaureate Nursing Students

ERIC Educational Resources Information Center

Nelson, Kesha Marie

2017-01-01

African-American baccalaureate nursing students have a limited persistence to graduation. This constructivist grounded theory study was designed to generate a substantive theory, emerged from these data, that explained and provided insight the African-American academic nurse leader's role in the persistence to graduation of African-American…

African Games of Strategy: A Teaching Manual. African Outreach Series, No. 2.

ERIC Educational Resources Information Center

Crane, Louise

Appreciation of African games has increased in this country; especially board games which have been popularized through commercial versions. African games are invaluable resources for studying subjects requiring mathematical concepts, as well as social studies, history, geography, and languages. This manual presents some of the better known…

African Ancestry is a Risk Factor for Asthma and High Total IgE Levels in African Admixed Populations

PubMed Central

Vergara, Candelaria; Murray, Tanda; Rafaels, Nicholas; Lewis, Rachel; Campbell, Monica; Foster, Cassandra; Gao, Li; Faruque, Mezbah; Oliveira, Ricardo Riccio; Carvalho, Edgar; Araujo, Maria Ilma; Cruz, Alvaro A.; Watson, Harold; Mercado, Dilia; Knight-Madden, Jennifer; Ruczinski, Ingo; Dunston, Georgia; Ford, Jean; Caraballo, Luis; Beaty, Terri H.; Mathias, Rasika A.; Barnes, Kathleen C.

2014-01-01

Characterization of genetic admixture of populations in the Americas and the Caribbean is of interest for anthropological, epidemiological, and historical reasons. Asthma has a higher prevalence and is more severe in populations with a high African component. Association of African ancestry with asthma has been demonstrated. We estimated admixture proportions of samples from six trihybrid populations of African descent and determined the relationship between African ancestry and asthma and total serum IgE levels (tIgE). We genotyped 237 ancestry informative markers in asthmatics and nonasthmatic controls from Barbados (190/277), Jamaica (177/529), Brazil (40/220), Colombia (508/625), African Americans from New York (207/171), and African Americans from Baltimore/Washington, D.C. (625/757). We estimated individual ancestries and evaluated genetic stratification using Structure and principal component analysis. Association of African ancestry and asthma and tIgE was evaluated by regression analysis. Mean SD African ancestry ranged from 0.76 ± 0.10 among Barbadians to 0.33 ± 0.13 in Colombians. The European component varied from 0.14 ± 0.05 among Jamaicans and Barbadians to 0.26 ± 0.08 among Colombians. African ancestry was associated with risk for asthma in Colombians (odds ratio (OR) = 4.5, P = 0.001) Brazilians (OR = 136.5, P = 0.003), and African Americans of New York (OR: 4.7; P = 0.040). African ancestry was also associated with higher tIgE levels among Colombians (β = 1.3, P = 0.04), Barbadians (β = 3.8, P = 0.03), and Brazilians (β = 1.6, P = 0.03). Our findings indicate that African ancestry can account for, at least in part, the association between asthma and its associated trait, tIgE levels. PMID:23554133

African genetic diversity provides novel insights into evolutionary history and local adaptations.

PubMed

Choudhury, Ananyo; Aron, Shaun; Sengupta, Dhriti; Hazelhurst, Scott; Ramsay, Michèle

2018-05-08

Genetic variation and susceptibility to disease are shaped by human demographic history. We can now study the genomes of extant Africans and uncover traces of population migration, admixture, assimilation and selection by applying sophisticated computational algorithms. There are four major ethnolinguistic divisions among present day Africans: Hunter-gatherer populations in southern and central Africa; Nilo-Saharan speakers from north and northeast Africa; Afro-Asiatic speakers from east Africa; and Niger-Congo speakers who are the predominant ethnolinguistic group spread across most of sub-Saharan Africa. The enormous ethnolinguistic diversity in sub-Saharan African populations is largely paralleled by extensive genetic diversity and until a decade ago, little was known about the origins and divergence of these groups. Results from large-scale population genetic studies, and more recently whole genome sequence data, are unraveling the critical role of events like migration and admixture and environment factors including diet, infectious diseases and climatic conditions in shaping current population diversity. It is now possible to start providing quantitative estimates of divergence times, population size and dynamic processes that have affected populations and their genetic risk for disease. Finally, the availability of ancient genomes from Africa is providing historical insights of unprecedented depth. In this review, we highlight some key interpretations that have emerged from recent African genome studies.

The face of Ebola: changing frequency of haemorrhage in the West African compared with Eastern-Central African outbreaks.

PubMed

Petti, Stefano; Messano, Giuseppe Alessio; Vingolo, Enzo Maria; Marsella, Luigi Tonino; Scully, Crispian

2015-12-11

The West-African (WA) Zaire Ebolavirus disease (EVD) outbreak was characterized by an exceptionally high number of cases and deaths as compared with the Eastern-Central African (ECA) outbreaks. Despite the Zaire Ebolavirus being the most lethal for humans, case-fatality rate, close to 80 % in ECA outbreaks, almost halved to 47 % in Guinea-Liberia-Sierra Leone (WA). Such an improvement was due to the remarkable implementation of international humanitarian aids. Some studies also suggested that the long human-to-human transmission cycle occurred in WA, gave rise to human adaptation and consequent immune escape. Haemorrhage, the main feature in seriously infected EVD patients, is due to the immune system that triggers the infected endothelial cells which expose the spike-like glycoprotein (GP) of the virion on their surface. If the human adaptation hypothesis holds true, the proportion of EVD patients with haemorrhage in the WA outbreak should be lower than in the ECA outbreaks due to immune escape. Therefore, the aim of this meta-analysis was to compare the relative frequencies of three typical haemorrhagic symptoms (conjunctival -CB, nasal -NB, gingival -GB- bleedings) in the ECA and WA outbreaks. Literature searches were performed through PubMed and Scopus using generic keywords; surveys including at least ten patients reporting CB, NB, GB relative frequencies were extracted and split into ECA and WA. The meta-analytical methods chosen were based on the levels of between-study heterogeneity and publication bias. Pooled CB, NB, GB relative frequencies in ECA and WA were estimated and compared. Subgroup analysis including only studies on Zaire Ebolavirus also was performed. Fifteen studies (10 ECA, 5 WA) were located with 4,867 (CB), 3,859 (NB), 4,278 (GB) EVD patients overall. GB pooled relative frequency was 45.3 % (95 % confidence interval -95 CI, 34.7-56.1 %) and 18.0 % (95 CI, 6.0-34.5 %), in ECA and WA; NB was 10.6 % (95 CI, 5.7-16.8 %) and 1.3 % (1

African American Therapists Working with African American Families: An Exploration of the Strengths Perspective in Treatment

ERIC Educational Resources Information Center

Bell-Tolliver, Laverne; Burgess, Ruby; Brock, Linda J.

2009-01-01

With the exception of Hill's (1971, 1999) work, historically much of the literature on African American families has focused more on pathology than strengths. This study used interviews with 30 African American psychotherapists, self-identified as employing a strengths perspective with African American families, to investigate which strengths they…

Investigating Instructional Practices of an African American Male Mathematics Teacher with Underachieving African American Male Students

ERIC Educational Resources Information Center

Muhammad, Rhonda K.

2012-01-01

This qualitative study examined the instructional practices of an experienced African American mathematics teacher to determine his perceived capabilities in augmenting academic proficiency for his African American male students. Provided in this descriptive case study are the lived experiences of an African American male teacher working to move…

Molecular epidemiology of 58 new African human T-cell leukemia virus type 1 (HTLV-1) strains: identification of a new and distinct HTLV-1 molecular subtype in Central Africa and in Pygmies.

PubMed Central

Mahieux, R; Ibrahim, F; Mauclere, P; Herve, V; Michel, P; Tekaia, F; Chappey, C; Garin, B; Van Der Ryst, E; Guillemain, B; Ledru, E; Delaporte, E; de The, G; Gessain, A

1997-01-01

To gain new insights on the origin, evolution, and modes of dissemination of human T-cell leukemia virus type I (HTLV-1), we performed a molecular analysis of 58 new African HTLV-1 strains (18 from West Africa, 36 from Central Africa, and 4 from South Africa) originating from 13 countries. Of particular interest were eight strains from Pygmies of remote areas of Cameroon and the Central African Republic (CAR), considered to be the oldest inhabitants of these regions. Eight long-term activated T-cell lines producing HTLV-1 gag and env antigens were established from peripheral blood mononuclear cell cultures of HTLV-1 seropositive individuals, including three from Pygmies. A fragment of the env gene encompassing most of the gp21 transmembrane region was sequenced for the 58 new strains, while the complete long terminal repeat (LTR) region was sequenced for 9 strains, including 4 from Pygmies. Comparative sequence analyses and phylogenetic studies performed on both the env and LTR regions by the neighbor-joining and DNA parsimony methods demonstrated that all 22 strains from West and South Africa belong to the widespread cosmopolitan subtype (also called HTLV-1 subtype A). Within or alongside the previously described Zairian cluster (HTLV-1 subtype B), we discovered a number of new HTLV-1 variants forming different subgroups corresponding mainly to the geographical origins of the infected persons, Cameroon, Gabon, and Zaire. Six of the eight Pygmy strains clustered together within this Central African subtype, suggesting a common origin. Furthermore, three new strains (two originating from Pygmies from Cameroon and the CAR, respectively, and one from a Gabonese individual) were particularly divergent and formed a distinct new phylogenetic cluster, characterized by specific mutations and occupying in most analyses a unique phylogenetic position between the large Central African genotype (HTLV-1 subtype B) and the Melanesian subtype (HTLV-1 subtype C). We have

Pan-African Genetic Structure in the African Buffalo (Syncerus caffer): Investigating Intraspecific Divergence

PubMed Central

Smitz, Nathalie; Berthouly, Cécile; Cornélis, Daniel; Heller, Rasmus; Van Hooft, Pim; Chardonnet, Philippe; Caron, Alexandre; Prins, Herbert; van Vuuren, Bettine Jansen; De Iongh, Hans; Michaux, Johan

2013-01-01

The African buffalo (Syncerus caffer) exhibits extreme morphological variability, which has led to controversies about the validity and taxonomic status of the various recognized subspecies. The present study aims to clarify these by inferring the pan-African spatial distribution of genetic diversity, using a comprehensive set of mitochondrial D-loop sequences from across the entire range of the species. All analyses converged on the existence of two distinct lineages, corresponding to a group encompassing West and Central African populations and a group encompassing East and Southern African populations. The former is currently assigned to two to three subspecies (S. c. nanus, S. c. brachyceros, S. c. aequinoctialis) and the latter to a separate subspecies (S. c. caffer). Forty-two per cent of the total amount of genetic diversity is explained by the between-lineage component, with one to seventeen female migrants per generation inferred as consistent with the isolation-with-migration model. The two lineages diverged between 145 000 to 449 000 years ago, with strong indications for a population expansion in both lineages, as revealed by coalescent-based analyses, summary statistics and a star-like topology of the haplotype network for the S. c. caffer lineage. A Bayesian analysis identified the most probable historical migration routes, with the Cape buffalo undertaking successive colonization events from Eastern toward Southern Africa. Furthermore, our analyses indicate that, in the West-Central African lineage, the forest ecophenotype may be a derived form of the savanna ecophenotype and not vice versa, as has previously been proposed. The African buffalo most likely expanded and diverged in the late to middle Pleistocene from an ancestral population located around the current-day Central African Republic, adapting morphologically to colonize new habitats, hence developing the variety of ecophenotypes observed today. PMID:23437100

A comparison of nephron number, glomerular volume and kidney weight in Senegalese Africans and African Americans

PubMed Central

McNamara, Bridgette J.; Diouf, Boucar; Douglas-Denton, Rebecca N.; Hughson, Michael D.; Hoy, Wendy E.; Bertram, John F.

2010-01-01

Background. Low nephron number is determined in utero and is a proposed risk for essential hypertension. Glomerular volume is inversely correlated with nephron number, and genetic and environmental factors that determine nephron number are thought to determine glomerular volume. This study compared total glomerular (nephron) number (Nglom), mean glomerular volume (Vglom) and kidney weight in two geographically separated black populations with significant common genetic ancestry. Methods. Unbiased stereology was used to determine Nglom and Vglom in kidneys collected at coronial autopsy in an age- and sex-matched sample of 39 adult Africans from Dakar in Senegal, West Africa and 39 African Americans from Mississippi in the USA. Results. African Americans were taller and heavier than their Senegalese counterparts. Nglom was remarkably similar—with a geometric mean of 937 967 in Senegalese and 904 412 in African Americans (P = 0.62). Vglom was correlated inversely with Nglom and directly with body surface area in both groups, but Vglom was 54% greater in African Americans than in Senegalese Africans [8.30 ± 2.92 (SD) and 5.38 ± 1.25  μm3 × 106, respectively] and remained significantly larger (38%) after adjustment for body size. Vglom increased with age in African Americans, but not in the Senegalese. Kidney weight was larger in African Americans (P < 0.0001), but kidney-to-body weight ratio was not different between groups. Conclusions. Despite similar nephron numbers, a common genetic constitution, and even in relation to current body size, African Americans have larger Vglom than Senegalese subjects. This may mark exposure to environmental stressors or hereditary traits concentrated in the population's relocation to North America. PMID:20154008

A comparison of nephron number, glomerular volume and kidney weight in Senegalese Africans and African Americans.

PubMed

McNamara, Bridgette J; Diouf, Boucar; Douglas-Denton, Rebecca N; Hughson, Michael D; Hoy, Wendy E; Bertram, John F

2010-05-01

Low nephron number is determined in utero and is a proposed risk for essential hypertension. Glomerular volume is inversely correlated with nephron number, and genetic and environmental factors that determine nephron number are thought to determine glomerular volume. This study compared total glomerular (nephron) number (N(glom)), mean glomerular volume (V(glom)) and kidney weight in two geographically separated black populations with significant common genetic ancestry. Unbiased stereology was used to determine N(glom) and V(glom) in kidneys collected at coronial autopsy in an age- and sex-matched sample of 39 adult Africans from Dakar in Senegal, West Africa and 39 African Americans from Mississippi in the USA. African Americans were taller and heavier than their Senegalese counterparts. N(glom) was remarkably similar-with a geometric mean of 937 967 in Senegalese and 904 412 in African Americans (P = 0.62). V(glom) was correlated inversely with N(glom) and directly with body surface area in both groups, but V(glom) was 54% greater in African Americans than in Senegalese Africans [8.30 +/- 2.92 (SD) and 5.38 +/- 1.25 microm(3) x 10(6), respectively] and remained significantly larger (38%) after adjustment for body size. V(glom) increased with age in African Americans, but not in the Senegalese. Kidney weight was larger in African Americans (P < 0.0001), but kidney-to-body weight ratio was not different between groups. Despite similar nephron numbers, a common genetic constitution, and even in relation to current body size, African Americans have larger V(glom) than Senegalese subjects. This may mark exposure to environmental stressors or hereditary traits concentrated in the population's relocation to North America.

Predicting Non-African American Lesbian and Heterosexual Preadoptive Couples' Openness to Adopting an African American Child

ERIC Educational Resources Information Center

Goldberg, Abbie E.; Smith, JuliAnna Z.

2009-01-01

Despite increases in transracial adoption, African American children remain the least likely to be adopted. No research has examined the factors that predict prospective adopters' willingness to adopt an African American child. This study used multilevel modeling to examine predictors of willingness to adopt an African American child in a sample…

Influences on Labor Market Outcomes of African American College Graduates: A National Study

ERIC Educational Resources Information Center

Strayhorn, Terrell L.

2008-01-01

Using an expanded econometric model, this study sought to estimate more precisely the net effect of independent variables (i.e., attending an HBCU) on three measures of labor market outcomes for African American college graduates. Findings reveal a statistically significant, albeit moderate, relationship between measures of background, human and…

Alu repeat discovery and characterization within human genomes

PubMed Central

Hormozdiari, Fereydoun; Alkan, Can; Ventura, Mario; Hajirasouliha, Iman; Malig, Maika; Hach, Faraz; Yorukoglu, Deniz; Dao, Phuong; Bakhshi, Marzieh; Sahinalp, S. Cenk; Eichler, Evan E.

2011-01-01

Human genomes are now being rapidly sequenced, but not all forms of genetic variation are routinely characterized. In this study, we focus on Alu retrotransposition events and seek to characterize differences in the pattern of mobile insertion between individuals based on the analysis of eight human genomes sequenced using next-generation sequencing. Applying a rapid read-pair analysis algorithm, we discover 4342 Alu insertions not found in the human reference genome and show that 98% of a selected subset (63/64) experimentally validate. Of these new insertions, 89% correspond to AluY elements, suggesting that they arose by retrotransposition. Eighty percent of the Alu insertions have not been previously reported and more novel events were detected in Africans when compared with non-African samples (76% vs. 69%). Using these data, we develop an experimental and computational screen to identify ancestry informative Alu retrotransposition events among different human populations. PMID:21131385

The Hominin Sites and Paleolakes Drilling Project: inferring the environmental context of human evolution from eastern African rift lake deposits

NASA Astrophysics Data System (ADS)

Cohen, A.; Campisano, C.; Arrowsmith, R.; Asrat, A.; Behrensmeyer, A. K.; Deino, A.; Feibel, C.; Hill, A.; Johnson, R.; Kingston, J.; Lamb, H.; Lowenstein, T.; Noren, A.; Olago, D.; Owen, R. B.; Potts, R.; Reed, K.; Renaut, R.; Schäbitz, F.; Tiercelin, J.-J.; Trauth, M. H.; Wynn, J.; Ivory, S.; Brady, K.; O'Grady, R.; Rodysill, J.; Githiri, J.; Russell, J.; Foerster, V.; Dommain, R.; Rucina, S.; Deocampo, D.; Russell, J.; Billingsley, A.; Beck, C.; Dorenbeck, G.; Dullo, L.; Feary, D.; Garello, D.; Gromig, R.; Johnson, T.; Junginger, A.; Karanja, M.; Kimburi, E.; Mbuthia, A.; McCartney, T.; McNulty, E.; Muiruri, V.; Nambiro, E.; Negash, E. W.; Njagi, D.; Wilson, J. N.; Rabideaux, N.; Raub, T.; Sier, M. J.; Smith, P.; Urban, J.; Warren, M.; Yadeta, M.; Yost, C.; Zinaye, B.

2016-02-01

The role that climate and environmental history may have played in influencing human evolution has been the focus of considerable interest and controversy among paleoanthropologists for decades. Prior attempts to understand the environmental history side of this equation have centered around the study of outcrop sediments and fossils adjacent to where fossil hominins (ancestors or close relatives of modern humans) are found, or from the study of deep sea drill cores. However, outcrop sediments are often highly weathered and thus are unsuitable for some types of paleoclimatic records, and deep sea core records come from long distances away from the actual fossil and stone tool remains. The Hominin Sites and Paleolakes Drilling Project (HSPDP) was developed to address these issues. The project has focused its efforts on the eastern African Rift Valley, where much of the evidence for early hominins has been recovered. We have collected about 2 km of sediment drill core from six basins in Kenya and Ethiopia, in lake deposits immediately adjacent to important fossil hominin and archaeological sites. Collectively these cores cover in time many of the key transitions and critical intervals in human evolutionary history over the last 4 Ma, such as the earliest stone tools, the origin of our own genus Homo, and the earliest anatomically modern Homo sapiens. Here we document the initial field, physical property, and core description results of the 2012-2014 HSPDP coring campaign.

South Africans Speak: Discussion Forum Presentations 1987-1989. South African Information Exchange Working Paper Number 12.

ERIC Educational Resources Information Center

Micou, Ann M., Ed.

Ten informal papers given at Discussion Forums to U.S. groups are provided which address current South African related issues as they touch upon the South African Information Exchange (SAIE) initiative. Papers have the following titles and authors: "Is There Space for American Involvement in South African Education?" (Merlyn C. Mehl);…

Triglyceride-based screening tests fail to recognize cardiometabolic disease in African immigrant and African-American men.

PubMed

Yu, Sophia S K; Ramsey, Natalie L M; Castillo, Darleen C; Ricks, Madia; Sumner, Anne E

2013-02-01

The prevalence of cardiometabolic disease in Africa now rivals that of Western nations. Therefore, screening programs that lead to effective prevention of cardiometabolic disease in Africans is imperative. Most screening tests for cardiometabolic disease use triglyceride (TG) levels as a criterion. However, the failure rate of TG-based screening tests in African Americans is high. In Africans, the efficacy of TG-based screening tests is unknown. Our goal was to determine the association between hypertriglyceridemia (TG ≥150 mg/dL) and cardiometabolic disease in African and African-American men. This was a cross-sectional study of 155 men (80 African immigrants, 75 African Americans) [age, 35±9 years, mean±standard deviation (SD), body mass index (BMI) 28.5±5.2 kg/m(2)] who self-identified as healthy. Lipid profiles were performed. Glucose tolerance and insulin resistance was determined by oral glucose tolerance tests (OGTT) and the insulin sensitivity index (S(I)), respectively. Cardiometabolic disease was defined by four possible subtypes--prediabetes, diabetes, insulin resistance, or metabolic triad [hyperinsulinemia, hyperapolipoprotein B, small low-density lipoprotein (LDL) particles]. TG levels were higher in men with cardiometabolic disease than without (88±43 versus 61±26 mg/dL, P<0.01). However, <10% of men with cardiometabolic disease had TG ≥150 mg/dL. Even within each cardiometabolic disease subtype, the prevalence of TG ≥150 mg/dL was <10%. Furthermore, TG levels in the 5% of men identified by OGTT as diabetic were ≤100 mg/dL (mean 71±24, range 45-100 mg/dL). Hypertriglyceridemia is a poor marker of cardiometabolic disease in men of African descent. Therefore TG-based screening tests fail to identify both African immigrants and African-American men with cardiometabolic disease. As a consequence, the opportunity for early intervention and prevention is lost.

Differences in HIV natural history among African and non-African seroconverters in Europe and seroconverters in sub-Saharan Africa.

PubMed

Pantazis, Nikos; Morrison, Charles; Amornkul, Pauli N; Lewden, Charlotte; Salata, Robert A; Minga, Albert; Chipato, Tsungai; Jaffe, Harold; Lakhi, Shabir; Karita, Etienne; Porter, Kholoud; Meyer, Laurence; Touloumi, Giota

2012-01-01

It is unknown whether HIV treatment guidelines, based on resource-rich country cohorts, are applicable to African populations. We estimated CD4 cell loss in ART-naïve, AIDS-free individuals using mixed models allowing for random intercept and slope, and time from seroconversion to clinical AIDS, death and antiretroviral therapy (ART) initiation by survival methods. Using CASCADE data from 20 European and 3 sub-Saharan African (SSA) cohorts of heterosexually-infected individuals, aged ≥15 years, infected ≥2000, we compared estimates between non-African Europeans, Africans in Europe, and Africans in SSA. Of 1,959 (913 non-Africans, 302 Europeans-African origin, 744 SSA), two-thirds were female; median age at seroconversion was 31 years. Individuals in SSA progressed faster to clinical AIDS but not to death or non-TB AIDS. They also initiated ART later than Europeans and at lower CD4 cell counts. In adjusted models, Africans (especially from Europe) had lower CD4 counts at seroconversion and slower CD4 decline than non-African Europeans. Median (95% CI) CD4 count at seroconversion for a 15-29 year old woman was 607 (588-627) (non-African European), 469 (442-497) (European-African origin) and 570 (551-589) (SSA) cells/µL with respective CD4 decline during the first 4 years of 259 (228-289), 155 (110-200), and 199 (174-224) cells/µL (p<0.01). Despite differences in CD4 cell count evolution, death and non-TB AIDS rates were similar across study groups. It is therefore prudent to apply current ART guidelines from resource-rich countries to African populations.

Nurses' performance on indigenous and African-Brazilian health care practices.

PubMed

Lima, Maria do Rosário de Araújo; Nunes, Maria Luísa de Almeida; Klüppel, Berta Lúcia Pinheiro; Medeiros, Soraya Maria de; Sá, Lenilde Duarte de

2016-01-01

to analyze the performance of nurses from the Estratégia Saúde da Família (Family Health Strategy) on health care practices rooted in African and Indigenous cultures. Thematic Oral History was used and interviews were conducted with seven participants, who worked with Primary Health Care in Northeastern Brazil. The analysis was based on Leininger's Theory of Cultural Care and the intercultural concept of human rights, among others. nurses are unaware of the religious and historical context of the ethnic groups cared for and do not appreciate their self-care practices in areas with a predominance of African and indigenous cultures. These practices coexist with the hegemonic biomedical model. the debate on cultural competence in the context of professional qualification and exercise is required, aiming to promote the nursing work in the perspective of diversity and comprehensiveness of health care.

Spirituality: a cultural strength for African American mothers with HIV.

PubMed

Polzer Casarez, Rebecca L; Miles, Margaret Shandor

2008-05-01

The purpose of this study was to describe how spirituality affected the lives of African American mothers with Human Immunodeficiency Virus (HIV) in the context of coping. This qualitative descriptive study used secondary data of interviews from a larger longitudinal study of parental caregiving of infants seropositive for HIV. Participants were 38 African American mothers with HIV. Data from longitudinal semi-structured interviews were analyzed using content analysis. The women dealt with the stresses of HIV through a relationship with God. Two domains explain this relationship: God in control and God requires participation. The benefits of their relationship with God were a decrease in stress and worry about their own health and that of their infants. It is important for nurses working with mothers with HIV to acknowledge their spirituality and assess how spirituality helps them cope with and manage their illness.

Africanization in the United States: replacement of feral European honeybees (Apis mellifera L.) by an African hybrid swarm.

PubMed

Pinto, M Alice; Rubink, William L; Patton, John C; Coulson, Robert N; Johnston, J Spencer

2005-08-01

The expansion of Africanized honeybees from South America to the southwestern United States in <50 years is considered one of the most spectacular biological invasions yet documented. In the American tropics, it has been shown that during their expansion Africanized honeybees have low levels of introgressed alleles from resident European populations. In the United States, it has been speculated, but not shown, that Africanized honeybees would hybridize extensively with European honeybees. Here we report a continuous 11-year study investigating temporal changes in the genetic structure of a feral population from the southern United States undergoing Africanization. Our microsatellite data showed that (1) the process of Africanization involved both maternal and paternal bidirectional gene flow between European and Africanized honeybees and (2) the panmitic European population was replaced by panmitic mixtures of A. m. scutellata and European genes within 5 years after Africanization. The post-Africanization gene pool (1998-2001) was composed of a diverse array of recombinant classes with a substantial European genetic contribution (mean 25-37%). Therefore, the resulting feral honeybee population of south Texas was best viewed as a hybrid swarm.

Records of human activity during the late-Holocene in the soils of the African dense humid forest

NASA Astrophysics Data System (ADS)

Morin-Rivat, Julie; Bentaleb, Ilham; Biwolé, Achille; Bourland, Nils; Bremond, Laurent; Daïnou, Kasso; Fayolle, Adeline; Gillet, Jean-François; Gorel, Anaïs; Gourlet-Fleury, Sylvie; Hardy, Olivier; Livingstone Smith, Alexandre; Oslisly, Richard; Vleminckx, Jason; Beeckman, Hans; Doucet, Jean-Louis

2014-05-01

Recently, several authors gathered data about the presence of past human populations in tropical regions covered by dense forest nowadays. In Central Africa, there is a growing body of evidence for past human settlements along the Atlantic coast, but very little information is available further inland. In the perspective, soil records seem to be the most appropriated so as to appraise the spatial and temporal extent of human activity in the African dense humid forest. In this paper, we thus aimed to present a synthesis of the archaeological and archaeobotanical data obtained during several fieldwork campaigns in an archaeologically unexplored area of 200,000 km² located in southern Cameroon and the northern Republic of Congo. A total of 275 test pits, among them 30 pedological pits up to 150 cm deep, were excavated in the study area. So as to get a long temporal scale as well as a fine resolution spatial scale, we quantified wood charcoal and charred endocarps in soil samples by layers of 10 cm taken for 100 pits located along transects of systematic sampling. Spatial projections were performed using statistics together with multivariate analyses. AMS radiocarbon dating allowed interpreting the temporal framework. Evidence of past human activities through either artifacts or charred botanical remains was observed in all pits, in particular with the ubiquitous presence of charcoal at each site. Main charcoal peaks were interpreted as fields (slash-and-burn agriculture) in the vicinity of ancient villages, the later marked by the presence of both potsherds and oil palm endocarps. The dichotomy of these kinds of activities may have impacted differentially the environment during the past. The set of 73 radiocarbon dates extending from 15,000 BP to the present time provided more dates in the late-Holocene showing a bimodal distribution which was interpreted as two phases of human expansion with an intermediate phase of population crash. The 2300-1300 BP phase is

Genetic analysis shows low levels of hybridization between African wildcats (Felis silvestris lybica) and domestic cats (F. s. catus) in South Africa

PubMed Central

Le Roux, Johannes J; Foxcroft, Llewellyn C; Herbst, Marna; MacFadyen, Sandra

2015-01-01

Hybridization between domestic and wild animals is a major concern for biodiversity conservation, and as habitats become increasingly fragmented, conserving biodiversity at all levels, including genetic, becomes increasingly important. Except for tropical forests and true deserts, African wildcats occur across the African continent; however, almost no work has been carried out to assess its genetic status and extent of hybridization with domestic cats. For example, in South Africa it has been argued that the long-term viability of maintaining pure wildcat populations lies in large protected areas only, isolated from human populations. Two of the largest protected areas in Africa, the Kgalagadi Transfrontier and Kruger National Parks, as well as the size of South Africa and range of landscape uses, provide a model situation to assess how habitat fragmentation and heterogeneity influences the genetic purity of African wildcats. Using population genetic and home range data, we examined the genetic purity of African wildcats and their suspected hybrids across South Africa, including areas within and outside of protected areas. Overall, we found African wildcat populations to be genetically relatively pure, but instances of hybridization and a significant relationship between the genetic distinctiveness (purity) of wildcats and human population pressure were evident. The genetically purest African wildcats were found in the Kgalagadi Transfrontier Park, while samples from around Kruger National Park showed cause for concern, especially combined with the substantial human population density along the park's boundary. While African wildcat populations in South Africa generally appear to be genetically pure, with low levels of hybridization, our genetic data do suggest that protected areas may play an important role in maintaining genetic purity by reducing the likelihood of contact with domestic cats. We suggest that approaches such as corridors between protected areas

Mechanisms of Vowel Variation in African American English.

PubMed

Holt, Yolanda Feimster

2018-02-15

This research explored mechanisms of vowel variation in African American English by comparing 2 geographically distant groups of African American and White American English speakers for participation in the African American Shift and the Southern Vowel Shift. Thirty-two male (African American: n = 16, White American controls: n = 16) lifelong residents of cities in eastern and western North Carolina produced heed,hid,heyd,head,had,hod,hawed,whod,hood,hoed,hide,howed,hoyd, and heard 3 times each in random order. Formant frequency, duration, and acoustic analyses were completed for the vowels /i, ɪ, e, ɛ, æ, ɑ, ɔ, u, ʊ, o, aɪ, aʊ, oɪ, ɝ/ produced in the listed words. African American English speakers show vowel variation. In the west, the African American English speakers are participating in the Southern Vowel Shift and hod fronting of the African American Shift. In the east, neither the African American English speakers nor their White peers are participating in the Southern Vowel Shift. The African American English speakers show limited participation in the African American Shift. The results provide evidence of regional and socio-ethnic variation in African American English in North Carolina.

The ethics of improving African traditional medical practice: scientific or African traditional research methods?

PubMed

Nyika, Aceme

2009-11-01

The disease burden in Africa, which is relatively very large compared with developed countries, has been attributed to various factors that include poverty, food shortages, inadequate access to health care and unaffordability of Western medicines to the majority of African populations. Although for 'old diseases' knowledge about the right African traditional medicines to treat or cure the diseases has been passed from generation to generation, knowledge about traditional medicines to treat newly emerging diseases has to be generated in one way or another. In addition, the existing traditional medicines have to be continuously improved, which is also the case with Western scientific medicines. Whereas one school of thought supports the idea of improving medicines, be they traditional or Western, through scientific research, an opposing school of thought argues that subjecting African traditional medicines to scientific research would be tantamount to some form of colonization and imperialism. This paper argues that continuing to use African traditional medicines for old and new diseases without making concerted efforts to improve their efficacy and safety is unethical since the disease burden affecting Africa may continue to rise in spite of the availability and accessibility of the traditional medicines. Most importantly, the paper commends efforts being made in some African countries to improve African traditional medicine through a combination of different mechanisms that include the controversial approach of scientific research on traditional medicines.

The secretory pattern and source of immunoreactive prolactin in pregnant African (Loxodonta africana) and Asian (Elephas maximus) elephants.

PubMed

Yamamoto, Yuki; Yamamoto, Tatsuya; Yuto, Natsuki; Hildebrandt, Thomas B; Lueders, Imke; Wibbelt, Gudrun; Shiina, Osamu; Mouri, Yasushi; Sugimura, Keisuke; Sakamoto, Sayuri; Kaewmanee, Saroch; Nagaoka, Kentaro; Watanabe, Gen; Taya, Kazuyoshi

2012-01-01

The objective of the present study was to define the secretion of prolactin (PRL) in pregnant African and Asian elephants. Levels of immunoreactive (ir-) PRL in serum and placental homogenates were measured by a heterologous radioimmunoassay (RIA) based on an ovine and human RIA system, and the localization of ir-PRL in the placenta was detected by immunohistochemistry using anti-human PRL. Circulating ir-PRL clearly showed a biphasic pattern during pregnancy in African and Asian elephants. Serum levels of ir-PRL started to increase from the 4 - 6th month of gestation and reached the first peak level around the 11-14th month. A second peak of circulating ir-PRL levels was observed around the 18-20th month of gestation followed by an abrupt decline after parturition. In contrast, in a case of abortion of an African elephant, the second peak of ir-PRL was not observed, and the levels remained low for about four months until parturition. The weight of the fetus delivered at the 17th month of gestation was 23.5 kg, which was quite small compared with normal fetuses in previous reports. Ir-PRL was detected in placental homogenates, and immunolocalization was observed in trophoblasts in both the African and Asian elephants, indicating that the placenta is the source of ir-PRL during pregnancy in elephants. The present results clearly demonstrated that circulating ir-PRL shows a biphasic pattern during normal pregnancy and that the placenta appears to be an important source of circulating ir-PRL during pregnancy in both African and Asian elephants.

Characterization of casein and alpha lactalbumin of African elephant (Loxodonta africana) milk.

PubMed

Madende, M; Osthoff, G; Patterton, H-G; Patterton, H E; Martin, P; Opperman, D J

2015-12-01

The current research reports partial characterization of the caseins and α-lactalbumin (α-LA) of the African elephant with proposed unique structure-function properties. Extensive research has been carried out to understand the structure of the casein micelles. Crystallographic structure elucidation of caseins and casein micelles is not possible. Consequently, several models have been developed in an effort to describe the casein micelle, specifically of cow milk. Here we report the characterization of African elephant milk caseins. The κ-caseins and β-caseins were investigated, and their relative ratio was found to be approximately 1:8.5, whereas α-caseins were not detected. The gene sequence of β-casein in the NCBI database was revisited, and a different sequence in the N-terminal region is proposed. Amino acid sequence alignment and hydropathy plots showed that the κ-casein of African elephant milk is similar to that of other mammals, whereas the β-casein is similar to the human protein, and displayed a section of unique AA composition and additional hydrophilic regions compared with bovine caseins. Elephant milk is destabilized by 62% alcohol, and it is speculated that the β-casein characteristics may allow maintenance of the colloidal nature of the casein micelle, a role that was previously only associated with κ-casein. The oligosaccharide content of milk was reported to be low in dairy animals but high in some other species such as humans and elephants. In the milk of the African elephant, lactose and oligosaccharides both occur at high levels. These levels are typically related to the content of α-LA in the mammary gland and thus point to a specialized carbohydrate synthesis, where the whey protein α-LA plays a role. We report the characterization of African elephant α-LA. Homology modeling of the α-LA showed that it is structurally similar to crystal structures of other mammalian species, which in turn may be an indication that its functional

African Retentions in Blues and Jazz.

ERIC Educational Resources Information Center

Meadows, Eddie S.

1979-01-01

The perseverance of African musical characteristics among American Blacks is an historic reality. African retentions have been recorded in Black music of the antebellum period. Various African scales and rhythms permeate Black American music today as evidenced in the retentions found in blues and jazz. (RLV)

Teacher Education from an African American Perspective.

ERIC Educational Resources Information Center

Hilliard, Asa G., III

This paper focuses on African education and socialization processes and how these have evolved and spread through the African cultural diaspora to other parts of the world, before, during, and after the slave trade and the colonial period. The history of education on the African continent is explored, followed by African American education, and…

Cenozoic East African Magmatism and the African LLSVP

NASA Astrophysics Data System (ADS)

Rooney, T. O.

2017-12-01

The Ethiopian-Arabian Large Igneous Province preserves a 45 Ma record of mantle-lithosphere interaction, manifesting as flood basalts, shield volcanoes, silicic eruptions, and monogenetic magmatic events. During the Cenozoic, magmatism in in this region has resulted from the interplay between lithospheric extension and material upwelling from the African large low-velocity shear velocity province (LLSVP). Consequently, the study of magmatism in East Africa provides a complement to investigations of the Pacific LLSVP. The volumetrically significant flood basalt events of the Eocene to Early Miocene suggest a role for material upwelling from the African LLSVP, however the modern focusing of East African magmatism into oceanic spreading centers and continental rifts also highlights the control of lithospheric thinning in magma generation processes. The study of the mantle reservoirs derived from the African LLSVP is complicated by the slow relative motion of the African plate during the Cenozoic, resulting in significant spatial overlap in lavas derived from different magmatic events. This complexity is being resolved with enhanced geochronological precision and a focus on the geochemical characteristics of the volcanic products. It is now apparent that there are three distinct pulses of basaltic volcanism, followed by either by bimodal or silicic volcanism, totaling ca. 720,000 km3 of magmatism: (A) Eocene Initial Phase from 45-34 Ma, which is dominated by basaltic volcanism and focused on Southern Ethiopia and Northern Kenya (Turkana). (B) Oligocene Traps phase from 33.9-27 Ma, which coincides with a significant increase in the aerial extent of volcanism. Broadly age equivalent 1 to 2 km thick sequences of dominantly basalt are centered on the NW Ethiopian Plateau and Yemen, but also Turkana during this period. (C) Early Miocene resurgence phase from 26.9-22 Ma, where basaltic volcanism is seen throughout the region but is less volumetrically significant than the

Genotoxicity profile of fexinidazole--a drug candidate in clinical development for human African trypanomiasis (sleeping sickness).

PubMed

Tweats, David; Bourdin Trunz, Bernadette; Torreele, Els

2012-09-01

The parasitic disease human African trypanomiasis (HAT), also known as sleeping sickness, is a highly neglected fatal condition endemic in sub-Saharan Africa, which is poorly treated with medicines that are toxic, no longer effective or very difficult to administer. New, safe, effective and easy-to-use treatments are urgently needed. Many nitroimidazoles possess antibacterial and antiprotozoal activity and examples such as tinidazole are used to treat trichomoniasis and guardiasis, but concerns about toxicity including genotoxicity limit their usefulness. Fexinidazole, a 2-substituted 5-nitroimidazole rediscovered by the Drugs for Neglected Diseases initiative (DNDi) after extensive compound mining of public and pharmaceutical company databases, has the potential to become a short-course, safe and effective oral treatment, curing both acute and chronic HAT. This paper describes the genotoxicity profile of fexinidazole and its two active metabolites, the sulfoxide and sulfone derivatives. All the three compounds are mutagenic in the Salmonella/Ames test; however, mutagenicity is either attenuated or lost in Ames Salmonella strains that lack one or more nitroreductase(s). It is known that these enzymes can nitroreduce compounds with low redox potentials, whereas their mammalian cell counterparts cannot, under normal conditions. Fexinidazole and its metabolites have low redox potentials and all mammalian cell assays to detect genetic toxicity, conducted for this study either in vitro (micronucleus test in human lymphocytes) or in vivo (ex vivo unscheduled DNA synthesis in rats; bone marrow micronucleus test in mice), were negative. Thus, fexinidazole does not pose a genotoxic hazard to patients and represents a promising drug candidate for HAT. Fexinidazole is expected to enter Phase II clinical trials in 2012.

H3Africa and the African Life Sciences Ecosystem: Building Sustainable Innovation

PubMed Central

Huzair, Farah; Borda-Rodriguez, Alexander; Chirikure, Shadreck; Okpechi, Ikechi; Warnich, Louise; Masimirembwa, Collen

2014-01-01

Abstract Interest in genomics research in African populations is experiencing exponential growth. This enthusiasm stems in part from the recognition that the genomic diversity of African populations is a window of opportunity for innovations in postgenomics medicine, ecology, and evolutionary biology. The recently launched H3Africa initiative, for example, captures the energy and momentum of this interest. This interdisciplinary socio-technical analysis highlights the challenges that have beset previous genomics research activities in Africa, and looking ahead, suggests constructive ways H3Africa and similar large scale science efforts could usefully chart a new era of genomics and life sciences research in Africa that is locally productive and globally competitive. As independent African scholars and social scientists, we propose that any serious global omics science effort, including H3Africa, aiming to build genomics research capacity and capability in Africa, needs to fund the establishment of biobanks and the genomic analyses platforms within Africa. Equally they need to prioritize community engagement and bioinformatics capability and the training of African scientists on these platforms. Historically, the financial, technological, and skills imbalance between Africa and developed countries has created exploitative frameworks of collaboration where African researchers have become merely facilitators of Western funded and conceived research agendas involving offshore expatriation of samples. Not surprisingly, very little funding was allocated to infrastructure and human capital development in the past. Moving forward, capacity building should materialize throughout the entire knowledge co-production trajectory: idea generation (e.g., brainstorming workshops for innovative hypotheses development by African scientists), data generation (e.g., genome sequencing), and high-throughput data analysis and contextualization. Additionally, building skills for political

H3Africa and the African life sciences ecosystem: building sustainable innovation.

PubMed

Dandara, Collet; Huzair, Farah; Borda-Rodriguez, Alexander; Chirikure, Shadreck; Okpechi, Ikechi; Warnich, Louise; Masimirembwa, Collen

2014-12-01

Interest in genomics research in African populations is experiencing exponential growth. This enthusiasm stems in part from the recognition that the genomic diversity of African populations is a window of opportunity for innovations in postgenomics medicine, ecology, and evolutionary biology. The recently launched H3Africa initiative, for example, captures the energy and momentum of this interest. This interdisciplinary socio-technical analysis highlights the challenges that have beset previous genomics research activities in Africa, and looking ahead, suggests constructive ways H3Africa and similar large scale science efforts could usefully chart a new era of genomics and life sciences research in Africa that is locally productive and globally competitive. As independent African scholars and social scientists, we propose that any serious global omics science effort, including H3Africa, aiming to build genomics research capacity and capability in Africa, needs to fund the establishment of biobanks and the genomic analyses platforms within Africa. Equally they need to prioritize community engagement and bioinformatics capability and the training of African scientists on these platforms. Historically, the financial, technological, and skills imbalance between Africa and developed countries has created exploitative frameworks of collaboration where African researchers have become merely facilitators of Western funded and conceived research agendas involving offshore expatriation of samples. Not surprisingly, very little funding was allocated to infrastructure and human capital development in the past. Moving forward, capacity building should materialize throughout the entire knowledge co-production trajectory: idea generation (e.g., brainstorming workshops for innovative hypotheses development by African scientists), data generation (e.g., genome sequencing), and high-throughput data analysis and contextualization. Additionally, building skills for political science

"Women...mourn and men carry on": African women storying mourning practices: a South African example.

PubMed

Kotzé, Elmarie; Els, Lishje; Rajuili-Masilo, Ntsiki

2012-09-01

African mourning of loss of lives in South Africa has been shaped by discursive practices of both traditional African cultures and the sociopolitical developments under apartheid and in post-apartheid South Africa. This article reports on changes in mourning practices on the basis of a literature review and uses a collection of examples to highlight the navigation of some cultural and gendered issues relating to mourning, against the backdrop of the everyday experiences of loss of life in South Africa due to violence and HIV/AIDS. The article draws on African womanist and feminist scholarship and focuses on the intersections between cultural and gender practices of bereavement in the lives of professional urban African women. The authors argue for the use of positioning theory and witnessing practices to honor and story the ongoing struggle of African women as these women take different agentic positions by accepting, questioning, resisting, and/or changing cultural mourning practices while they compassionately witness the self and others in the narratives they live.

The Application of Embodied Conversational Agents for Mentoring African American STEM Doctoral Students

ERIC Educational Resources Information Center

Gosha, Kinnis

2013-01-01

This dissertation presents the design, development and short-term evaluation of an embodied conversational agent designed to mentor human users. An embodied conversational agent (ECA) was created and programmed to mentor African American computer science majors on their decision to pursue graduate study in computing. Before constructing the ECA,…

Genome-wide association analysis of blood-pressure traits in African-ancestry individuals reveals common associated genes in African and non-African populations.

PubMed

Franceschini, Nora; Fox, Ervin; Zhang, Zhaogong; Edwards, Todd L; Nalls, Michael A; Sung, Yun Ju; Tayo, Bamidele O; Sun, Yan V; Gottesman, Omri; Adeyemo, Adebawole; Johnson, Andrew D; Young, J Hunter; Rice, Ken; Duan, Qing; Chen, Fang; Li, Yun; Tang, Hua; Fornage, Myriam; Keene, Keith L; Andrews, Jeanette S; Smith, Jennifer A; Faul, Jessica D; Guangfa, Zhang; Guo, Wei; Liu, Yu; Murray, Sarah S; Musani, Solomon K; Srinivasan, Sathanur; Velez Edwards, Digna R; Wang, Heming; Becker, Lewis C; Bovet, Pascal; Bochud, Murielle; Broeckel, Ulrich; Burnier, Michel; Carty, Cara; Chasman, Daniel I; Ehret, Georg; Chen, Wei-Min; Chen, Guanjie; Chen, Wei; Ding, Jingzhong; Dreisbach, Albert W; Evans, Michele K; Guo, Xiuqing; Garcia, Melissa E; Jensen, Rich; Keller, Margaux F; Lettre, Guillaume; Lotay, Vaneet; Martin, Lisa W; Moore, Jason H; Morrison, Alanna C; Mosley, Thomas H; Ogunniyi, Adesola; Palmas, Walter; Papanicolaou, George; Penman, Alan; Polak, Joseph F; Ridker, Paul M; Salako, Babatunde; Singleton, Andrew B; Shriner, Daniel; Taylor, Kent D; Vasan, Ramachandran; Wiggins, Kerri; Williams, Scott M; Yanek, Lisa R; Zhao, Wei; Zonderman, Alan B; Becker, Diane M; Berenson, Gerald; Boerwinkle, Eric; Bottinger, Erwin; Cushman, Mary; Eaton, Charles; Nyberg, Fredrik; Heiss, Gerardo; Hirschhron, Joel N; Howard, Virginia J; Karczewsk, Konrad J; Lanktree, Matthew B; Liu, Kiang; Liu, Yongmei; Loos, Ruth; Margolis, Karen; Snyder, Michael; Psaty, Bruce M; Schork, Nicholas J; Weir, David R; Rotimi, Charles N; Sale, Michele M; Harris, Tamara; Kardia, Sharon L R; Hunt, Steven C; Arnett, Donna; Redline, Susan; Cooper, Richard S; Risch, Neil J; Rao, D C; Rotter, Jerome I; Chakravarti, Aravinda; Reiner, Alex P; Levy, Daniel; Keating, Brendan J; Zhu, Xiaofeng

2013-09-05

High blood pressure (BP) is more prevalent and contributes to more severe manifestations of cardiovascular disease (CVD) in African Americans than in any other United States ethnic group. Several small African-ancestry (AA) BP genome-wide association studies (GWASs) have been published, but their findings have failed to replicate to date. We report on a large AA BP GWAS meta-analysis that includes 29,378 individuals from 19 discovery cohorts and subsequent replication in additional samples of AA (n = 10,386), European ancestry (EA) (n = 69,395), and East Asian ancestry (n = 19,601). Five loci (EVX1-HOXA, ULK4, RSPO3, PLEKHG1, and SOX6) reached genome-wide significance (p < 1.0 × 10(-8)) for either systolic or diastolic BP in a transethnic meta-analysis after correction for multiple testing. Three of these BP loci (EVX1-HOXA, RSPO3, and PLEKHG1) lack previous associations with BP. We also identified one independent signal in a known BP locus (SOX6) and provide evidence for fine mapping in four additional validated BP loci. We also demonstrate that validated EA BP GWAS loci, considered jointly, show significant effects in AA samples. Consequently, these findings suggest that BP loci might have universal effects across studied populations, demonstrating that multiethnic samples are an essential component in identifying, fine mapping, and understanding their trait variability. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Gentle Africanized bees on an oceanic island

PubMed Central

Rivera-Marchand, Bert; Oskay, Devrim; Giray, Tugrul

2012-01-01

Oceanic islands have reduced resources and natural enemies and potentially affect life history traits of arriving organisms. Among the most spectacular invasions in the Western hemisphere is that of the Africanized honeybee. We hypothesized that in the oceanic island Puerto Rico, Africanized bees will exhibit differences from the mainland population such as for defensiveness and other linked traits. We evaluated the extent of Africanization through three typical Africanized traits: wing size, defensive behavior, and resistance to Varroa destructor mites. All sampled colonies were Africanized by maternal descent, with over 65% presence of European alleles at the S-3 nuclear locus. In two assays evaluating defense, Puerto Rican bees showed low defensiveness similar to European bees. In morphology and resistance to mites, Africanized bees from Puerto Rico are similar to other Africanized bees. In behavioral assays on mechanisms of resistance to Varroa, we directly observed that Puerto Rican Africanized bees groomed-off and bit the mites as been observed in other studies. In no other location, Africanized bees have reduced defensiveness while retaining typical traits such as wing size and mite resistance. This mosaic of traits that has resulted during the invasion of an oceanic island has implications for behavior, evolution, and agriculture. PMID:23144660

The Relationship of African Apes, Man, and Old World Monkeys

PubMed Central

Leakey, L. S. B.

1970-01-01

The conclusions of Wilson and Sarich (Proc. Nat. Acad. Sci. USA, 63, 1088-1093 (1969) that the human lineage diverged from that leading to the African apes about 4 to 5 million years ago is shown to be based upon a wholly unsupported assumption that the Superfamilies Hominoidea and Cercopithecoidea only separated from each other some 30 million years ago. This is entirely contrary to most recent palaeontological evidence. PMID:5002096

Intraseasonal variability of the West African monsoon and African easterly waves during boreal summer

NASA Astrophysics Data System (ADS)

Alaka, Ghassan J., Jr.

Substantial subseasonal variability in African easterly wave (AEW) activity and cyclogenesis frequency occurs in the main hurricane development region of the Atlantic during boreal summer. A complete understanding of intraseasonal variability in the Atlantic and west Africa during boreal summer requires analysis of how the Madden-Julian Oscillation (MJO) modulates the west African monsoon and consequently AEWs. Because the MJO is predictable a few weeks in advance, understanding how and why the MJO impacts the west African monsoon may have a profound influence on Atlantic tropical cyclone prediction. This study documents the MJO influence on the west African monsoon system during boreal summer using a variety of reanalysis and satellite datasets. This study aims to identify and explain the MJO teleconnection to the west African monsoon, and the processes that induce precipitation and AEW variability in this region. Intraseasonal west African and Atlantic convective anomalies on 30-90 day timescales are likely induced by equatorial Kelvin and Rossby waves generated in the Indian Ocean and west Pacific by the MJO. Previous studies have hypothesized that an area including the Darfur mountains and the Ethiopian highlands is an initiation region for AEWs. It is shown here that the initial MJO influence on precipitation and AEW activity in the African monsoon appears to occur in these regions, where eddy kinetic energy (EKE) anomalies first appear in advance of MJO-induced periods of enhanced and suppressed AEW activity. In the initiation region, upper tropospheric temperature anomalies are reduced, the atmosphere moistens by horizontal advection, and an eastward extension of the African easterly jet occurs in advance of the MJO wet phase of the African monsoon, when AEW activity is also enhanced. These factors all support strong precursor disturbances in the initiation region that seed the African easterly jet and contribute to downstream development of AEWs. Opposite

Survival Disparity of African American Versus Non-African American Patients With ESRD Due to SLE.

PubMed

Nee, Robert; Martinez-Osorio, Jorge; Yuan, Christina M; Little, Dustin J; Watson, Maura A; Agodoa, Lawrence; Abbott, Kevin C

2015-10-01

A recent study showed an increased risk of death in African Americans compared with whites with end-stage renal disease (ESRD) due to lupus nephritis (LN). We assessed the impact of age stratification, socioeconomic factors, and kidney transplantation on the disparity in patient survival among African American versus non-African American patients with LN-caused ESRD, compared with other causes. Retrospective cohort study. Using the US Renal Data System database, we identified 12,352 patients with LN-caused ESRD among 1,132,202 patients who initiated maintenance dialysis therapy from January 1, 1995, through December 31, 2006, and were followed up until December 31, 2010. Baseline demographics and comorbid conditions, Hispanic ethnicity, socioeconomic factors (employment status, Medicare/Medicaid insurance, and area-level median household income based on zip code as obtained from the 2000 US census), and kidney transplantation as a time-dependent variable. All-cause mortality. Multivariable Cox and competing-risk regressions. Mean duration of follow-up in the LN-caused ESRD and other-cause ESRD cohorts were 6.24±4.20 (SD) and 4.06±3.61 years, respectively. 6,106 patients with LN-caused ESRD (49.43%) and 853,762 patients with other-cause ESRD (76.24%) died during the study period (P<0.001). Patients with LN-caused ESRD were significantly younger (mean age, 39.92 years) and more likely women (81.65%) and African American (48.13%) than those with other-cause ESRD. In the fully adjusted multivariable Cox regression model, African American (vs non-African American) patients with LN-caused ESRD had significantly increased risk of death at age 18 to 30 years (adjusted HR, 1.43; 95% CI, 1.24-1.65) and at age 31 to 40 years (adjusted HR, 1.17; 95% CI, 1.02-1.34). Among patients with other-cause ESRD, African Americans were at significantly increased risk at age 18 to 30 years (adjusted HR, 1.17; 95% CI, 1.11-1.22). We used zip code-based median household income as a

African Genetic Ancestry is Associated with Sleep Depth in Older African Americans

PubMed Central

Halder, Indrani; Matthews, Karen A.; Buysse, Daniel J.; Strollo, Patrick J.; Causer, Victoria; Reis, Steven E.; Hall, Martica H.

2015-01-01

Study Objectives: The mechanisms that underlie differences in sleep characteristics between European Americans (EA) and African Americans (AA) are not fully known. Although social and psychological processes that differ by race are possible mediators, the substantial heritability of sleep characteristics also suggests genetic underpinnings of race differences. We hypothesized that racial differences in sleep phenotypes would show an association with objectively measured individual genetic ancestry in AAs. Design: Cross sectional. Setting: Community-based study. Participants: Seventy AA adults (mean age 59.5 ± 6.7 y; 62% female) and 101 EAs (mean age 60.5 ± 7 y, 39% female). Measurements and Results: Multivariate tests were used to compare the Pittsburgh Sleep Quality Index (PSQI) and in-home polysomnographic measures of sleep duration, sleep efficiency, apnea-hypopnea index (AHI), and indices of sleep depth including percent visually scored slow wave sleep (SWS) and delta EEG power of EAs and AAs. Sleep duration, efficiency, and sleep depth differed significantly by race. Individual % African ancestry (%AF) was measured in AA subjects using a panel of 1698 ancestry informative genetic markers and ranged from 10% to 88% (mean 67%). Hierarchical linear regression showed that higher %AF was associated with lower percent SWS in AAs (β (standard error) = −4.6 (1.5); P = 0.002), and explained 11% of the variation in SWS after covariate adjustment. A similar association was observed for delta power. No association was observed for sleep duration and efficiency. Conclusion: African genetic ancestry is associated with indices of sleep depth in African Americans. Such an association suggests that part of the racial differences in slow-wave sleep may have genetic underpinnings. Citation: Halder I, Matthews KA, Buysse DJ, Strollo PJ, Causer V, Reis SE, Hall MH. African genetic ancestry is associated with sleep depth in older African Americans. SLEEP 2015;38(8):1185–1193

Being stressed outside the park—conservation of African elephants (Loxodonta africana) in Namibia

PubMed Central

Ringstad, Iris H; Jackson, Craig R; May, Roel; Fossøy, Frode; Uiseb, Kenneth; Killian, Werner; Palme, Rupert; Røskaft, Eivin

2017-01-01

Abstract The conservation of the African savanna elephant (Loxodonta africana) is of prime importance for many African countries. Interactions between elephants and humans are known to induce stress and thereby have the potential to affect elephants’ fitness. In Namibia, anthropogenic disturbances are increasing due to increasing human population size and development, particularly near protected areas, such as national parks. In this study, we investigated elephant stress levels in relation to their land use, specifically their protection status, comparing elephants within Etosha National Park in Namibia with elephants residing outside the park. We noninvasively collected dung samples of 91 elephants and determined the concentration of faecal glucocorticoid metabolites (fGCM), an indicator of physiological stress. Elephants outside the park (N = 35) had significantly higher concentrations of fGCM than those inside ENP (N = 56), suggesting that, despite including community-based conservancies, unprotected areas are more stressful for elephants than protected areas, most likely due to increased interactions with humans. We also found that males had lower fGCM concentrations than females, but no significant effect of age, body size or group size was detected. Additionally, herd sizes were significantly smaller and calf recruitment was potentially lower in unprotected areas. These findings underpin the importance of protected areas such as ENP, while encouraging decision-makers to continue reducing and mitigating potential human-induced disturbances. PMID:29270294

A Systematic Review of HIV Serostatus Disclosure Among African Immigrants in Europe.

PubMed

Whembolua, Guy-Lucien; Conserve, Donaldson F; Thomas, Kirstyn; Handler, Lara

2017-08-01

As the human immunodeficiency virus continues to devastate large parts of Africa, particularly the Sub-Saharan region, the number of immigrants migrating from these areas to European nations continues to grow. African men and women leave their countries for Europe because of armed conflicts, unemployment, or poverty. Thus, these migration patterns combined with newly contracted infections have resulted in a large and growing number of HIV-positive diagnoses among African immigrants living in Europe. Using the disclosure process model, this systematic review examines the reasons for HIV status disclosure and nondisclosure among African immigrants residing in Europe. PubMed, PsycINFO, Embase, Global Health, and Web of Science were searched. Bibliographies of retrieved studies were also reviewed for other relevant citations. Studies were eligible if they: (1) focused on HIV-positive immigrants from SSA residing in Europe; and (2) described or measured HIV status disclosure. Out of 166 articles found, a total of 17 articles and 1 brief report met the inclusion criteria. Factors such as stigma and social implications of disclosure contribute to avoidance goals leading to nondisclosure while approach goals or disclosure reasons were found to include health status and behaviors such as seeking support, and helping others. The findings highlight the importance of understanding the avoidance and approach goals involved in HIV status disclosure among African immigrants in Europe. Interventions and future research directed at increasing HIV disclosure among African immigrants in Europe should move beyond individual-level to consider multilevel factors including country-specific social behaviors.

Molecular defects leading to human complement component C6 deficiency in an African-American family

PubMed Central

Zhu, Z-B; Totemchokchyakarn, K; Atkinson, T P; Volanakis, J E

1998-01-01

Complement component C6 deficiency (C6D) was diagnosed in a 16-year-old African-American male with meningococcal meningitis. The patient's father and two brothers also had C6D, but gave no history of meningitis or other neisserial infection. By using exon-specific polymerase chain reaction (PCR)/single-strand conformation polymorphism as a screening step and nucleotide sequencing of target exons, we determined that the proband was a compound heterozygote for two C6 gene mutations. The first, 1195delC located in exon 7, is a novel mutation, while the second, 1936delG in exon 12, has been described before to cause C6D in an unrelated African-American individual. Both mutations result in premature termination codons and C6 null alleles. Allele-specific PCR indicated that the proband's two brothers also inherited the 1195delC mutation from their heterozygous mother and the 1936delG mutation from their homozygous father. PMID:9472666

Aspirations and Equality in Higher Education: Gender in a South African University

ERIC Educational Resources Information Center

Walker, Melanie

2018-01-01

This paper considers ways to theorise aspirations in terms of capabilities and agency to function as human beings, as well as our resources to act and participate in this world using a South African case of women students' aspirations. In this analysis higher education should foster women's freedom as critical agents to make genuine choices about…

Evaluating long-term effectiveness of sleeping sickness control measures in Guinea.

PubMed

Pandey, Abhishek; Atkins, Katherine E; Bucheton, Bruno; Camara, Mamadou; Aksoy, Serap; Galvani, Alison P; Ndeffo-Mbah, Martial L

2015-10-22

Human African Trypanosomiasis threatens human health across Africa. The subspecies T.b. gambiense is responsible for the vast majority of reported HAT cases. Over the past decade, expanded control efforts accomplished a substantial reduction in HAT transmission, spurring the WHO to include Gambian HAT on its roadmap for 2020 elimination. To inform the implementation of this elimination goal, we evaluated the likelihood that current control interventions will achieve the 2020 target in Boffa prefecture in Guinea, which has one of the highest prevalences for HAT in the country, and where vector control measures have been implemented in combination with the traditional screen and treat strategy. We developed a three-species mathematical model of HAT and used a Bayesian melding approach to calibrate the model to epidemiological and entomological data from Boffa. From the calibrated model, we generated the probabilistic predictions regarding the likelihood that the current HAT control programs could achieve elimination by 2020 in Boffa. Our model projections indicate that if annual vector control is implemented in combination with annual or biennial active case detection and treatment, the probability of eliminating HAT as public health problem in Boffa by 2020 is over 90%. Annual implementation of vector control alone has a significant impact but a decreased chance of reaching the objective (77%). However, if the ongoing control efforts are interrupted, HAT will continue to remain a public health problem. In the presence of a non-human animal transmission reservoir, intervention strategies must be maintained at high coverage, even after 2020 elimination, to prevent HAT reemerging as a public health problem. Complementing active screening and treatment with vector control has the potential to achieve the elimination target before 2020 in the Boffa focus. However, surveillance must continue after elimination to prevent reemergence.

Judgments of Widely Held Beliefs about Psychological Phenomena among South African Postgraduate Psychology Students

ERIC Educational Resources Information Center

Kagee, A.; Harper, M.; Spies, G.

2008-01-01

Lay understandings of human cognition, affect, and behaviour often diverge from the findings of scientific investigations. The present study examined South African fourth year psychology students' judgments about the factual correctness of statements of psychological phenomena that have been demonstrated to be incorrect by empirical research.…

Genetic risk variants in African Americans with multiple sclerosis

PubMed Central

Isobe, Noriko; Gourraud, Pierre-Antoine; Harbo, Hanne F.; Caillier, Stacy J.; Santaniello, Adam; Khankhanian, Pouya; Maiers, Martin; Spellman, Stephen; Cereb, Nezih; Yang, SooYoung; Pando, Marcelo J.; Piccio, Laura; Cross, Anne H.; De Jager, Philip L.; Cree, Bruce A.C.; Hauser, Stephen L.

2013-01-01

Objectives: To assess the association of established multiple sclerosis (MS) risk variants in 3,254 African Americans (1,162 cases and 2,092 controls). Methods: Human leukocyte antigen (HLA)-DRB1, HLA-DQB1, and HLA-A alleles were typed by molecular techniques. Single nucleotide polymorphism (SNP) genotyping was conducted for 76 MS-associated SNPs and 52 ancestry informative marker SNPs selected throughout the genome. Self-declared ancestry was refined by principal component analysis of the ancestry informative marker SNPs. An ancestry-adjusted multivariate model was applied to assess genetic associations. Results: The following major histocompatibility complex risk alleles were replicated: HLA-DRB1*15:01 (odds ratio [OR] = 2.02 [95% confidence interval: 1.54–2.63], p = 2.50e-07), HLA-DRB1*03:01 (OR = 1.58 [1.29–1.94], p = 1.11e-05), as well as HLA-DRB1*04:05 (OR = 2.35 [1.26–4.37], p = 0.007) and the African-specific risk allele of HLA-DRB1*15:03 (OR = 1.26 [1.05–1.51], p = 0.012). The protective association of HLA-A*02:01 was confirmed (OR = 0.72 [0.55–0.93], p = 0.013). None of the HLA-DQB1 alleles were associated with MS. Using a significance threshold of p < 0.01, outside the major histocompatibility complex region, 8 MS SNPs were also found to be associated with MS in African Americans. Conclusion: MS genetic risk in African Americans only partially overlaps with that of Europeans and could explain the difference of MS prevalence between populations. PMID:23771490

Academic achievement and career choice in science: Perceptions of African American urban high school students

NASA Astrophysics Data System (ADS)

Jones, Sheila Kay

2007-12-01