Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 463
Filtrar
1.
Zootaxa ; 5150(4): 556-578, 2022 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-36095647

RESUMO

Urocotyledon inexpectata, a small gecko endemic to the granitic islands of the Seychelles, has previously been demonstrated to comprise two highly distinct clades based on mitochondrial and nuclear DNA sequences, with one lineage exclusive to a northern group of islands, and the second lineage exclusive to the more southerly islands. Here we complement the genetic data with additional analyses to determine if the clades should be considered distinct species. We present and analyse new morphological data, including skull and jaw osteology, and supplement the available genetic data with DNA sequences for individuals from the previously unsampled island of Felicit, which cluster with the other northern island samples. Despite the high morphological similarity between Urocotyledon populations from northern and southern islands, diagnostic characters were identified, with the northern lineage having a more completely ossified skull, more tooth loci on maxilla and dentary, shorter hindlimbs, relatively smaller eye diameter and relatively wider head. We therefore describe the northern lineage as a distinct species, Urocotyledon norzilensis sp. nov., and discuss the biological and conservation management implications of this taxonomic action.


Assuntos
Lagartos , Animais , Lagartos/genética , Filogenia , Seicheles
2.
Neurotoxicology ; 92: 49-60, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35868427

RESUMO

In many studies of the health effects of toxicants, exposure is measured once even though exposure may be continuous. However, some studies collect repeated measurements on participants over an extended time with the goal of determining a long-term metric that captures the average or cumulative exposure. This can be challenging, especially when exposure is measured at irregular intervals and has some missing values. Here we describe a method for determining a measure of long-term exposure using data on postnatal mercury (Hg) from the Seychelles Child Development Study (SCDS) Main Cohort as a model. In this cohort (n = 779), we incorporate postnatal Hg values that were measured on most study participants at seven ages, three between 6 months and 5.5 years ("childhood"), and an additional four between 17 and 24 years ("early adulthood"). We develop time-weighted measures of average exposure during the childhood and the early adulthood periods and compare the strengths and weaknesses of our metric to two standard measures: overall average and cumulative exposure. We account for missing values through an imputation method that uses information about age- and sex-specific Hg means and the participant's Hg values at similar ages to estimate subject-specific missing Hg values. We compare our method to the implicit imputation assumed by these two standard methods, and to Fully Conditional Specification (FCS), an alternative method of imputing missing data. To determine the accuracy of our imputation method we use data from participants with no missing Hg values in the relevant time window. The imputed values from our proposed method are substantially closer to the observed values on average than the average or cumulative exposure, while also performing slightly better than FCS. In conclusion, time-weighted long-term exposure appears to offer advantages over cumulative exposure in longitudinal studies with repeated measures where the follow-up period for a toxicant is similar for all participants. Additionally, our method to impute missing values maximizes the number of participants for whom the overall exposure metric can be calculated and should provide a more accurate long-term exposure metric than standard methods when exposure has missing values. Our method is applicable to any study of long-term toxicant effects when longitudinal exposure measurements are available but have missing values.


Assuntos
Desenvolvimento Infantil , Mercúrio , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Mercúrio/análise , Projetos de Pesquisa , Seicheles , Adulto Jovem
3.
Neurotoxicology ; 91: 234-244, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35643326

RESUMO

PURPOSE: Methylmercury (MeHg) is a known neurodevelopmental toxicant in sufficient dosage and is universally found in fish. Current fish advisories for children are based on epidemiology studies examining prenatal exposure with a premise that MeHg exposure resulting from children eating fish could also be neurotoxic and have long-term consequences. However, the evidence that this assumption is true is limited. We investigated postnatal MeHg exposure from regular fish consumption using time weighted Hg measurements to determine if there are neurotoxic consequences. METHODS: We examined 85 neurodevelopmental outcomes measured from ages 9-24 years in the Seychelles Child Development Study Main Cohort (n = 312-550) and examined their association with time-weighted measures of postnatal MeHg exposure in childhood and early adulthood. Postnatal MeHg exposure measured in the first cm of participants' hair samples collected at seven evaluations were used to create two time-weighted (TW) average MeHg exposure metrics, one for childhood (TW-C) and the other for early adulthood (TW-A). TW-C was based on Hg measures at three ages between 6 months and 5.5 years, and TW-A was based on Hg measured at up to four ages between 17 and 24 years. We examined the association between each of these exposure metrics and the neurodevelopmental outcomes using linear regression with adjustment for covariates known to influence neurodevelopmental outcomes. RESULTS: There were 14 statistically significant associations between a postnatal metric and an endpoint. Six were associated with the TW-C and eight with the TW-A. Thirteen were adverse. Only the TW-C association at 9 years with the Bender Gestalt error score showed improvement. TW-C was adversely associated at 9 years with the Continuous Performance Task risk score, at 22 years with the Boston Naming Test (BNT) total and no cues scores, and at 24 years with the Test of Variables of Attention (TOVA) auditory response time variability and visual response time mean on the logarithmic scale. TW-A was adversely associated at 17 years with the Wisconsin Card Sorting Test % total errors, the Woodcock-Johnson passage comprehension, and the CANTAB rapid visual information processing false alarms, and at 22 years with the BNT total and no cue scores, the CANTAB rapid visual information processing false alarms and the intra-extra dimensional shift total errors and trials. CONCLUSION: These findings suggest that postnatal MeHg exposure may be adversely associated with neurodevelopmental outcomes in early adulthood. However, the associations are statistical and of unknown, if any, clinical significance. The results need confirmation in other cohorts.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Efeitos Tardios da Exposição Pré-Natal , Animais , Desenvolvimento Infantil , Feminino , Peixes , Contaminação de Alimentos , Humanos , Mercúrio/análise , Compostos de Metilmercúrio/análise , Compostos de Metilmercúrio/toxicidade , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Alimentos Marinhos/efeitos adversos , Seicheles/epidemiologia
4.
Neurotoxicology ; 91: 228-233, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35654246

RESUMO

BACKGROUND: There is emerging evidence that exposure to prenatal methylmercury (MeHg) from maternal fish consumption during pregnancy can differ between individuals due to genetic variation. In previous studies, we have reported that maternal polymorphisms in ABC-transporter genes were associated with maternal hair MeHg concentrations, and with children's early neurodevelopmental tests. In this study, we add to these findings by evaluating the contribution of genetic variation in children's ABC-transporter genes to prenatal MeHg exposure and early child neurodevelopmental tests. METHODS: We genotyped six polymorphisms (rs2032582, rs10276499 and rs1202169 in ABCB1; rs11075290 and rs215088 in ABCC1; rs717620 in ABCC2) in DNA from cord blood and maternal blood of the Seychelles Child Development Study Nutrition Cohort 2. We determined prenatal MeHg exposure by measuring total mercury (Hg) in cord blood by atomic fluorescence spectrometry. We assessed neurodevelopment in children at approximately 20 months using the Bayley Scales of Infant Development (BSID-II). We used linear regression models to analyze covariate-adjusted associations of child genotype with cord MeHg and BSID-II outcomes (Mental Developmental and Psychomotor Developmental Indexes). We also evaluated interactions between genotypes, cord MeHg, and neurodevelopmental outcomes. All models were run with and without adjustment for maternal genotype. RESULTS: Of the six evaluated polymorphisms, only ABCC1 rs11075290 was associated with cord blood MeHg; children homozygous for the T-allele had on average 29.99 µg/L MeHg in cord blood while those homozygous for the C-allele had on average 38.06 µg/L MeHg in cord blood (p < 0.001). No polymorphisms in the children were associated with either subscale of the BSID. However, the association between cord MeHg and the Mental Developmental Index (MDI) of the BSID differed significantly across the three genotypes of ABCB1 rs10276499 (2df F-test, p = 0.045). With increasing cord MeHg, the MDI decreased (slope=-0.091, p = 0.014) among children homozygous for the rare C-allele. CONCLUSIONS: These findings support the possibility that child ABC genetics might influence prenatal MeHg exposure.


Assuntos
Transportadores de Cassetes de Ligação de ATP , Mercúrio , Compostos de Metilmercúrio , Efeitos Tardios da Exposição Pré-Natal , Transportadores de Cassetes de Ligação de ATP/genética , Desenvolvimento Infantil , Estudos de Coortes , Feminino , Produtos Pesqueiros , Humanos , Lactente , Recém-Nascido , Exposição Materna , Compostos de Metilmercúrio/efeitos adversos , Gravidez , Efeitos Tardios da Exposição Pré-Natal/genética , Alimentos Marinhos/toxicidade , Seicheles
5.
Viruses ; 14(6)2022 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-35746789

RESUMO

Seychelles, an archipelago of 155 islands in the Indian Ocean, had confirmed 24,788 cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by the 31st of December 2021. The first SARS-CoV-2 cases in Seychelles were reported on the 14th of March 2020, but cases remained low until January 2021, when a surge was observed. Here, we investigated the potential drivers of the surge by genomic analysis of 1056 SARS-CoV-2 positive samples collected in Seychelles between 14 March 2020 and 31 December 2021. The Seychelles genomes were classified into 32 Pango lineages, 1042 of which fell within four variants of concern, i.e., Alpha, Beta, Delta and Omicron. Sporadic cases of SARS-CoV-2 detected in Seychelles in 2020 were mainly of lineage B.1 (lineage predominantly observed in Europe) but this lineage was rapidly replaced by Beta variant starting January 2021, and which was also subsequently replaced by the Delta variant in May 2021 that dominated till November 2021 when Omicron cases were identified. Using the ancestral state reconstruction approach, we estimated that at least 78 independent SARS-CoV-2 introduction events occurred in Seychelles during the study period. The majority of viral introductions into Seychelles occurred in 2021, despite substantial COVID-19 restrictions in place during this period. We conclude that the surge of SARS-CoV-2 cases in Seychelles in January 2021 was primarily due to the introduction of more transmissible SARS-CoV-2 variants into the islands.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/epidemiologia , Genômica , Humanos , SARS-CoV-2/genética , Seicheles/epidemiologia
6.
Mol Phylogenet Evol ; 174: 107514, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35589055

RESUMO

The systematics of the African frog family Hyperoliidae has undergone turbulent changes in last decades. Representatives of several genera have not been genetically investigated or with only limited data, and their phylogenetic positions are thus still not reliably known. This is the case of the De Witte's Clicking Frog (Kassinula wittei) which belongs to a monotypic genus. This miniature frog occurs in a poorly studied region, southeastern Democratic Republic of the Congo, northern Zambia, Angola. So far it is not settled whether this genus belongs to the subfamily Kassininae as a relative of the genus Kassina, or to the subfamily Hyperoliinae as a relative of the genus Afrixalus. Here we present for the first time a multilocus phylogenetic reconstruction (using five nuclear and one mitochondrial marker) of the family Hyperoliidae, including Kassinula. We demonstrate with high confidence that Kassinula is a member of Hyperoliinae belonging to a clade also containing Afrixalus (sub-Saharan Africa), Heterixalus (Madagascar) and Tachycnemis (Seychelles). We find that Kassinula represents a divergent lineage (17-25 Mya), which supports its separate genus-level status, but its exact systematic position remains uncertain. We propose to name the clade to which the above four genera belong as the tribe Tachycnemini Channing, 1989. A new taxonomy of the family Hyperoliidae was recently proposed by Dubois et al. (2021: Megataxa 5, 1-738). We demonstrate here that the new taxonomy was based on a partially erroneous phylogenetic reconstruction resulting from a supermatrix analysis of chimeric DNA sequences combining data from two families, Hyperoliidae and Arthroleptidae (the case of Cryptothylax). We therefore correct the erroneous part and propose a new, revised suprageneric taxonomy of the family Hyperoliidae. We also emphasize the importance of inspecting individual genetic markers before their concatenation or coalescent-based tree reconstructions to avoid analyses of chimeric DNA sequences producing incorrect phylogenetic reconstructions. Especially when phylogenetic reconstructions are used to propose taxonomies and systematic classifications.


Assuntos
Anuros , Animais , Anuros/genética , Madagáscar , Filogenia , Seicheles , Zâmbia
7.
J Fish Biol ; 100(1): 62-81, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34622456

RESUMO

The Lepadichthys lineatus complex (Gobiesocidae: Diademichthyinae) is defined by three unique characters within Lepadichthys: (a) upper-jaw lip fused with snout skin, usually lacking a distinct groove between the dorsal lip margin and snout (if present, very weak, restricted to posterior portion of jaw); (b) snout tip well extended, distinctly beyond lower-jaw tip; and (c) inner surface of both lips with oral papillae. A taxonomic review of the complex recognized four valid species: Lepadichthys geminus sp. nov. (southern Japan and Indonesia), Lepadichthys heemstraorum sp. nov. (southwestern Indian Ocean), Lepadichthys polyastrous sp. nov. (southwestern Indian Ocean) and L. lineatus Briggs, 1966 (Red Sea, Arabian Sea, Seychelles and Sri Lanka). L. geminus and L. lineatus are distinct from L. heemstraorum and L. polyastrous in having a circular (vs. elliptical) disc and more posteriorly located anus [L. geminus and L. lineatus with disc length and width 15.0-18.7 (mean 16.9) and 12.9-16.5 (14.6) % LS , respectively, and length to width ratio 1.03-1.25 cf. L. heemstraorum and L. polyastrous, 17.0-21.5 (18.9) and 11.6-15.2 (13.0) % LS , respectively, and 1.26-1.61; pre-anus length and disc to anus length 65.1-73.6 (68.7) and 25.7-31.6 (28.6) % LS , respectively vs. 60.2-68.3 (65.3) and 21.6-28.9 (25.5) % LS , respectively]. Body depth (as % of LS ) is also useful to distinguish L. geminus and L. polyastrous from L. heemstraorum and L. lineatus [viz., 12.7-16.1 (14.4) in L. geminus and 10.8-14.9 (13.1) in L. polyastrous vs. 15.0-17.1 (15.9) in L. heemstraorum and 14.6-18.9 (16.8) in L. lineatus]. L. geminus differs distinctly from other species in the complex as follows: snout tip directed upward, usually on same horizontal level with lower margin of eye lens (lateral view) (vs. directed somewhat downward, horizontal level usually between lower margins of eye and eye lens in L. heemstraorum and L. lineatus, lower margin of eye in L. polyastrous); and lower abdomen with two yellow stripes (vs. a single stripe along ventral midline in L. polyastrous and L. lineatus, unknown in L. heemstraorum). L. polyastrous has unique patterns of yellow dots on the dorsal and ventral body surfaces, forming c. six to eight and three to five longitudinal rows, respectively [vs. usually forming c. three to five longitudinal rows and a single broken line, respectively, in L. geminus and L. lineatus; yellow dots usually absent in L. heemstraorum]. A poorly known species, Lepadichthys caritus Briggs, 1969, is regarded as a junior synonym of L. lineatus.


Assuntos
Perciformes , Distribuição Animal , Animais , Peixes , Oceano Índico , Indonésia , Seicheles
8.
Environ Res ; 204(Pt A): 112003, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34492279

RESUMO

BACKGROUND: Maternal fish consumption increases infant methylmercury (MeHg) exposure and polyunsaturated fatty acid (PUFA) concentrations. The n-3 PUFA are regulators of inflammation while MeHg may impact the cord cytokine profile and, subsequently, contribute to immune mediated outcomes. This study aimed to investigate associations between infant MeHg exposure and cord cytokine concentrations while adjusting for cord PUFA. METHODS: We studied participants in the Seychelles Child Development Study (SCDS) Nutrition Cohort 2 (NC2), a large birth cohort in a high fish-eating population. Whole blood MeHg, serum PUFA and serum cytokine concentrations (IFN-γ, IL-1ß, IL-2, IL-12p70, TNF-α, IL-4, IL-10, IL-13, IL-6 and IL-8) were measured in cord blood collected at delivery (n = 878). Linear regression examined associations between infant MeHg exposure and cord cytokines concentrations, with and without adjustment for cord PUFA. An interaction model examined cord MeHg, cytokines and tertiles of the n-6:n-3 ratio (low/medium/high). RESULTS: There was no overall association between cord MeHg (34.08 ± 19.98 µg/L) and cytokine concentrations, with or without adjustment for PUFA. Increased total n-3 PUFA (DHA, EPA and ALA) was significantly associated with lower IL-10 (ß = -0.667; p = 0.007) and lower total Th2 (IL-4, IL-10 and IL-13) (ß = -0.715; p = 0.036). In the interaction model, MeHg and IL-1ß was positive and significantly different from zero in the lowest n-6:n-3 ratio tertile (ß = 0.002, p = 0.03). CONCLUSION: Methylmercury exposure from fish consumption does not appear to impact markers of inflammation in cord blood. The association of cord n-3 PUFA with lower IL-10 and total Th2 cytokines suggests that they may have a beneficial influence on the regulation of the inflammatory milieu. These findings are important for public health advice and deserve to be investigated in follow up studies.


Assuntos
Ácidos Graxos Ômega-3 , Compostos de Metilmercúrio , Animais , Criança , Desenvolvimento Infantil , Citocinas , Ácidos Graxos Insaturados , Sangue Fetal , Humanos , Lactente , Seicheles
9.
PLoS One ; 16(12): e0260516, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34874982

RESUMO

Coral recruitment and successive growth are essential for post-disturbance reef recovery. As coral recruit and juvenile abundances vary across locations and under different environmental regimes, their assessment at remote, undisturbed reefs improves our understanding of early life stage dynamics of corals. Here, we first explored changes in coral juvenile abundance across three locations (lagoon, seaward west and east) at remote Aldabra Atoll (Seychelles) between 2015 and 2019, which spanned the 2015/16 global coral bleaching event. Secondly, we measured variation in coral recruit abundance on settlement tiles from two sites (lagoon, seaward reef) during August 2018-August 2019. Juvenile abundance decreased from 14.1 ± 1.2 to 7.4 ± 0.5 colonies m-2 (mean ± SE) during 2015-2016 and increased to 22.4 ± 1.2 colonies m-2 during 2016-2019. Whilst juvenile abundance increased two- to three-fold at the lagoonal and seaward western sites during 2016-2018 (from 7.7-8.3 to 17.3-24.7 colonies m-2), increases at the seaward eastern sites occurred later (2018-2019; from 5.8-6.9 to 16.6-24.1 colonies m-2). The composition of coral recruits on settlement tiles was dominated by Pocilloporidae (64-92% of all recruits), and recruit abundance was 7- to 47-fold higher inside than outside the lagoon. Recruit abundance was highest in October-December 2018 (2164 ± 453 recruits m-2) and lowest in June-August 2019 (240 ± 98 recruits m-2). As Acroporid recruit abundance corresponded to this trend, the results suggest that broadcast spawning occurred during October-December, when water temperature increased from 26 to 29°C. This study provides the first published record on coral recruit abundance in the Seychelles Outer Islands, indicates a rapid (2-3 years) increase of juvenile corals following a bleaching event, and provides crucial baseline data for future research on reef resilience and connectivity within the region.


Assuntos
Antozoários/classificação , Antozoários/crescimento & desenvolvimento , Animais , /estatística & dados numéricos , Recifes de Corais , Aquecimento Global , Filogenia , Seicheles
10.
Zootaxa ; 5047(3): 201-246, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34810848

RESUMO

The Phalangopsidae crickets (Grylloidea) of the Seychelles are examined following extensive field sampling on several main islands of the archipelago (Mah, Silhouette, Praslin, La Digue). Despite the small area of these islands, six genera (12 species) are documented, including one new genus and five new species. The type species of the genus Seychellesia Bolivar, 1912 is transferred to the genus Paragryllodes Karny, 1909 as Paragryllodes nitidula (Bolivar, 1912) n. comb. The other species described in Seychellesia are transferred to the genus Seselia Hugel Desutter-Grandcolas, n. gen., as Seselia longicercata (Bolivar, 1912) n. comb. and Seselia patellifera (Bolivar, 1912) n. comb. Two new species are also described in the genus Seselia Hugel Desutter-Grandcolas, n. gen., Seselia coccofessei Hugel Desutter-Grandcolas, n. gen., n. sp. (type species of the genus) and Seselia matyoti Hugel Desutter-Grandcolas, n. gen., n. sp. The genera Phaeogryllus Bolivar, 1912 and Phalangacris Bolivar, 1895 are redescribed, including Phalangacris ferlegro Hugel Desutter-Grandcolas, n. sp. and Phalangacris sotsote Hugel Desutter-Grandcolas, n. sp. that are new to science. The genus Gryllapterus Bolivar, 1912 is redescribed and transferred from the Landrevinae (Gryllidae) to the Cachoplistinae (Phalangopsidae). New tribes are defined for the genus Paragryllodes (Paragryllodini Hugel Desutter-Grandcolas, n. tribe) on the one hand, and for Seselia Hugel Desutter-Grandcolas, n. gen., Phalangacris, Phaeogryllus and Gryllapterus (Seselini Hugel Desutter-Grandcolas, n. tribe) on the other, using morphological characters and the results of molecular phylogenetic studies (Warren et al. 2019). Phaloria (Papuloria) insularis (Bolivar, 1912) (Phaloriinae) is redescribed and restricted to Mah, and its calling song is documented for the first time, while Phaloria (Papuloria) bolivari Hugel Desutter-Grandcolas, n. sp. is newly described from Silhouette. Identification keys are proposed for the genera of Seselini Hugel Desutter-Grandcolas, n. tribe, and for the species of Seselia Hugel Desutter-Grandcolas, n. gen. and Phalangacris. The confusion between the Mogoplistidae Ornebius succineus Bolivar, 1912 and the Phalangopsidae Heterotrypus succineus Bolivar, 1910 is discussed, and the name Subtiloria succineus (Bolivar, 1912) considered a nomen nudum.


Assuntos
Besouros , Gryllidae , Ortópteros , Distribuição Animal , Estruturas Animais , Animais , Filogenia , Seicheles
12.
Matern Child Health J ; 25(12): 1930-1938, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34609706

RESUMO

OBJECTIVE: To determine if cesarean delivery is adversely associated with child neurodevelopment as measured at 20 months and 7 years. METHODS: In a prospective cohort study (n = 1328) in the Republic of Seychelles, we examined the association between mode of delivery and 22 measures of child neurodevelopment spanning multiple domains: cognition, executive and psychomotor function, language development, behavior, scholastic achievement, and social communication. Using multivariable linear regression, we evaluated the relationship between delivery mode (Cesarean/vaginal delivery) and each developmental outcome, while controlling for relevant covariates including child sex and age, maternal age, maternal IQ, whether both parents lived with the child, and Hollingshead socioeconomic status. RESULTS: At 20 months, children born via cesarean delivery had slightly higher scores (ß = 0.11, 95% confidence interval: 0.00, 0.21) on the Infant Behavior Questionnaire-Revised Positive Affectivity/Surgency subtest, a measure of infant temperament, as compared to vaginal delivery. Delivery mode was not associated with any of the 7-year developmental outcomes. CONCLUSIONS FOR PRACTICE: Our study does not support the notion that cesarean delivery is associated with child neurodevelopmental outcomes.


Assuntos
Cesárea , Desenvolvimento Infantil , Criança , Parto Obstétrico , Feminino , Humanos , Lactente , Gravidez , Estudos Prospectivos , Seicheles/epidemiologia
13.
J Nutr Sci ; 10: e71, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34527229

RESUMO

Maternal thyroid hormones facilitate optimal foetal neurodevelopment; however, the exact role of the thyroid hormones on specific cognitive outcomes is unknown. The present study aimed to investigate associations between maternal thyroid function and neurodevelopmental outcomes in the Seychelles Child Development Study (SCDS) Nutrition 2 cohort (n 1328). Maternal free thyroid hormones (fT3, fT4 and fTSH) were assessed at 28 weeks' gestation with a range of child cognitive outcomes analysed at 20 months. Dietary iodine intake was analysed for a subset of women through a Food Frequency Questionnaire. Linear regression analysis was used to test associations between serum concentrations of maternal thyroid hormones and child neurodevelopment outcomes. Thyroid hormones were analysed as continuous data and categorised as quintiles. 95% of mothers had optimal thyroid function based on fTSH concentrations. Overall, the present study shows that maternal thyroid function is not associated with neurodevelopmental outcomes in this high fish-eating population. However, a positive association, using quintiles for fT3, was reported for the Mental Developmental Index, between Q3 v. Q4 (ß 0⋅073; P 0⋅043) and for Q3 v. Q5 (ß value 0⋅086; P 0⋅018). To conclude, mothers in our cohort, who largely have optimal thyroid function and iodine intakes, appear able to regulate thyroid function throughout pregnancy to meet neurodevelopmental needs. However, it is possible that minor imbalances of fT3, as indicated from our secondary analysis, may impact offspring neurodevelopment. Further investigation of the relationship between maternal thyroid function and infant neurodevelopment is warranted, particularly in populations with different dietary patterns and thereby iodine intakes.


Assuntos
Desenvolvimento Infantil , Sistema Nervoso/crescimento & desenvolvimento , Glândula Tireoide , Feminino , Humanos , Lactente , Iodo/administração & dosagem , Mães , Gravidez , Seicheles , Glândula Tireoide/fisiologia , Hormônios Tireóideos/sangue
14.
Nutrients ; 13(7)2021 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-34371950

RESUMO

Long-chain omega-3 PUFAs, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are of increasing interest because of their favorable effect on cardiometabolic risk. This study explores the association between omega 6 and 3 fatty acids intake and cardiometabolic risk in four African-origin populations spanning the epidemiological transition. Data are obtained from a cohort of 2500 adults aged 25-45 enrolled in the Modeling the Epidemiologic Transition Study (METS), from the US, Ghana, Jamaica, and the Seychelles. Dietary intake was measured using two 24 h recalls from the Nutrient Data System for Research (NDSR). The prevalence of cardiometabolic risk was analyzed by comparing the lowest and highest quartile of omega-3 (EPA+ DHA) consumption and by comparing participants who consumed a ratio of arachidonic acid (AA)/EPA + DHA ≤4:1 and >4:1. Data were analyzed using multiple variable logistic regression adjusted for age, gender, activity, calorie intake, alcohol intake, and smoking status. The lowest quartile of EPA + DHA intake is associated with cardiometabolic risk 2.16 (1.45, 3.2), inflammation 1.59 (1.17, 2.16), and obesity 2.06 (1.50, 2.82). Additionally, consuming an AA/EPA + DHA ratio of >4:1 is also associated with cardiometabolic risk 1.80 (1.24, 2.60), inflammation 1.47 (1.06, 2.03), and obesity 1.72 (1.25, 2.39). Our findings corroborate previous research supporting a beneficial role for monounsaturated fatty acids in reducing cardiometabolic risk.


Assuntos
Fatores de Risco Cardiometabólico , Gorduras na Dieta/administração & dosagem , Ácidos Graxos Monoinsaturados/administração & dosagem , Ácidos Graxos Ômega-3/administração & dosagem , Ácidos Graxos Ômega-6/administração & dosagem , Adulto , Fibras na Dieta/administração & dosagem , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácido Eicosapentaenoico/administração & dosagem , Ácido Eicosapentaenoico/análogos & derivados , Feminino , Gana/epidemiologia , Humanos , Inflamação/epidemiologia , Jamaica/epidemiologia , Masculino , Pessoa de Meia-Idade , Obesidade/epidemiologia , Estudos Prospectivos , Seicheles/epidemiologia , Estados Unidos/epidemiologia
15.
PLoS One ; 16(8): e0256639, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34437618

RESUMO

Pontibacillus sp. ALD_SL1 and Psychroflexus sp. ALD_RP9 are two novel bacterial isolates from mangrove sediment and a moderately hypersaline pool on the Aldabra Atoll, Seychelles. The isolates represent two novel species were characterised physiologically and genomically. Pontibacillus sp. ALD_SL1 is a facultatively anaerobic yellow, motile, rod-shaped Gram-positive, which grows optimally at a NaCl concentration of 11%, pH 7 and 28°C. It is the third facultatively anaerobic member of the genus Pontibacillus. The organism gains energy through the fermentation of pyruvate to acetate and ethanol under anaerobic conditions. The genome is the first among Pontibacillus that harbours a megaplasmid. Psychroflexus sp. ALD_RP9 is an aerobic heterotroph, which can generate energy by employing bacteriorhodopsins. It forms Gram-negative, orange, non-motile rods. The strain grows optimally at NaCl concentrations of 10%, pH 6.5-8 and 20°C. The Psychroflexus isolate tolerated pH conditions up to 10.5, which is the highest pH tolerance currently recorded for the genus. Psychroflexus sp. ALD_RP9 taxonomically belongs to the clade with the smallest genomes. Both isolates show extensive adaptations to their saline environments yet utilise different mechanisms to ensure survival.


Assuntos
Bacillaceae/isolamento & purificação , Flavobacteriaceae/isolamento & purificação , Sedimentos Geológicos/microbiologia , Bacillaceae/enzimologia , Bacillaceae/crescimento & desenvolvimento , Bacillaceae/ultraestrutura , Flavobacteriaceae/enzimologia , Flavobacteriaceae/crescimento & desenvolvimento , Flavobacteriaceae/ultraestrutura , Genoma Bacteriano , Cinética , Filogenia , Seicheles , Microbiologia da Água
16.
J Health Care Poor Underserved ; 32(3): 1236-1264, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34421028

RESUMO

In recent years, there have been significant efforts to examine the organization and performance of health systems. This study's main purpose is to compare health systems and analyze the health status of the citizens of Comoros, Mauritius, and Seychelles, with the intention of providing policy recommendations for Comoros. Peer-reviewed studies and reports published by non-governmental organizations and international agencies were systematically collected through large database searches, filtered through methodological inclusion criteria, and organized into the World Health Organization (WHO) building blocks framework. The literature review demonstrates that health outcomes have dramatically improved over the past decades in Mauritius and Seychelles but not in Comoros. As of 2015, Mauritius and Seychelles were among the few African countries to have achieved almost all the Millennium Development Goals, whereas Comoros still struggles to reduce child mortality and improve maternal health. In contrast, the total health expenditure of the three island states, as a percentage of gross domestic product (GDP), seemed similar over the studied time period.


Assuntos
Atenção à Saúde , Criança , Comores , Humanos , Oceano Índico , Ilhas , Maurício , Seicheles/epidemiologia
17.
Environ Sci Pollut Res Int ; 28(39): 55252-55264, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34128165

RESUMO

Concentrations, profiles and muscle-liver distribution of halogenated natural products (HNPs) and anthropogenic persistent organic pollutants (POPs) were investigated in five large pelagic fish species and one smaller planktivore fish species from the Western Indian Ocean. Analysis of swordfish muscle from the Seychelles revealed the predominance of HNPs, with the highest concentrations found for 2'-methoxy-2,3',4,5'- tetraBDE (2'-MeO-BDE 68 or BC-2), 6-methoxy-2,2',4,4'- tetraBDE (6-MeO-BDE 47 or BC-3) and 2,3,3',4,4',5,5'-heptachloro-1'-methyl-1,2'-bipyrrole (Q1), along with varied contributions of further HNPs. The mean concentration of ∑HNPs (330 ng/g lw) was one or two orders of magnitude higher than ∑DDTs (60 ng/g lw) and ∑PCBs (6.8 ng/g lw). HNPs (BC-2, BC-3 and Q1) were also predominant in individual samples of three tropical tuna species from the Seychelles and from other regions of the Western Indian Ocean (Mozambique Channel, off Somalia and Chagos Archipelago). Non-targeted gas chromatography coupled with electron capture negative ion mass spectrometry operated in the selected ion monitoring mode (GC/ECNI-MS-SIM) analysis of one swordfish sample indicated low abundance of rarely reported HNPs (three hexachloro-1'-methyl-1,2'-bipyrrole (Cl6-MBP) isomers and pentabromo-1,1'-dimethyl-2,2'-bipyrroles (Br5-DBP)) but no further abundant unscreened polyhalogenated compounds.


Assuntos
Produtos Biológicos , Oceano Índico , Moçambique , Seicheles
19.
JCO Glob Oncol ; 7: 802-810, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34077269

RESUMO

PURPOSE: Cancer occurrence is increasing in Africa, although research has lagged. The objective of this review was to analyze cancer research outputs from Africa, with a particular focus on Zambia. METHODS: We searched PubMed for published cancer-related articles from African countries. All articles reporting on cancer in Africa were considered. We conducted analyses to explore correlations between cancer research output and total population, gross domestic product, and new cancer cases recorded in 2020. For Zambia articles, we also analyzed cancer types and time trends. RESULTS: A total of 48,487 cancer-related publications from Africa were identified, with nearly half coming from Egypt (13,372; 28%) and South Africa (9,393; 19%). Cancer research output correlated significantly with country population (Spearman's correlation coefficient 0.74; P < .001) and the number of new cancer cases recorded in 2020 (Spearman's correlation coefficient 0.77; P < .001). Standardized by population size, Western Sahara (0.576), Seychelles (0.244), Tunisia (0.239), South Africa (0.158), and Egypt (0.131) had the highest overall output per 1,000 population. A total of 244 publications were from Zambia; the most studied cancers were cervical (25%), Kaposi sarcoma (24%), and breast (10%). Although an increase in cancer research output from Zambia was noted, only 33% of publications were first or last authored by Zambians. The major limitation of this review is that the evaluation was based on a single electronic database, PubMed. CONCLUSION: Cancer research output from Africa is very low, with many of the publications concentrated in a few countries. There is an urgent need to invest in both human resources and infrastructure to increase cancer research output from African countries, particularly in less populous countries.


Assuntos
Neoplasias , Egito , Humanos , Neoplasias/epidemiologia , Seicheles , África do Sul , Tunísia , Zâmbia/epidemiologia
20.
Nat Commun ; 12(1): 3911, 2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-34162855

RESUMO

Empirical measurements of ecological networks such as food webs and mutualistic networks are often rich in structure but also noisy and error-prone, particularly for rare species for which observations are sparse. Focusing on the case of plant-pollinator networks, we here describe a Bayesian statistical technique that allows us to make accurate estimates of network structure and ecological metrics from such noisy observational data. Our method yields not only estimates of these quantities, but also estimates of their statistical errors, paving the way for principled statistical analyses of ecological variables and outcomes. We demonstrate the use of the method with an application to previously published data on plant-pollinator networks in the Seychelles archipelago and Kosciusko National Park, calculating estimates of network structure, network nestedness, and other characteristics.


Assuntos
Algoritmos , Insetos/fisiologia , Modelos Biológicos , Plantas/parasitologia , Polinização/fisiologia , Animais , Conservação dos Recursos Naturais/métodos , Conservação dos Recursos Naturais/estatística & dados numéricos , Ecossistema , Interações Hospedeiro-Parasita , New South Wales , Parques Recreativos , Seicheles
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...