162 research outputs found

    Evaluating current and future potential distribution of epiphytic orchids in the Congo Basin with ecological niche models

    Get PDF
    The Congo Basin Forest harbors a rich diversity of epiphytic communities, with the Orchidaceae alone making up more than 50% of all epiphytes in the region. Despite the huge diversity of epiphytes, many species, including epiphytic orchids, are at risk to a diverse array of threats. Climate change for instance poses severe threats to epiphytic orchids due to elevated temperatures, prolonged periods of droughts, as well as reduced rainfall across the Congo Basin Forest. In this study, we used ecological niche modeling and GIS techniques to identify spatial patterns of species richness, potential future climate refugia, and novel climatic suitability areas, by estimating future potential climatic suitability for epiphytic orchids in 2021-2040. We also evaluated the overlap of hotspots of climatic suitability for epiphytic orchids with the current network of protected areas in the Congo Basin. Using two Global Circulation Models and moderate and high greenhouse gasses emission scenarios, our results showed that, of the 16 species studied, nine species of epiphytic orchids would lose more than 30% of their current potentially suitable range. Additionally, spatial distribution of epiphytic orchids showed less than 5% overlap of potentially suitable climatic hotspots with the network of protected areas in the Congo Basin. Outside of protected areas our models forecasted stable areas buffering climatic changes (“slow lanes” or climate refugia) and as well novel climatic suitability areas across the biogeographic extent of Africa. Climate refugia and novel areas of climatic suitability may be crucial for long-term persistence and thriving of epiphytic orchids. These findings provide the first estimation to the potential distribution of epiphytic orchids in the Congo Basin and serve as a first step towards a regional effort to protect the biodiversity of the Guineo-Congolian landscape

    Socioeconomics of the Production and Marketing of Haricot Beans (Phaseolus vulgaris L.) in the Western Highlands of Cameroon

    Get PDF
    There has been an increase in the demand for Haricot beans (Phaseolus vulgaris L.) in Cameroon, most especially from buyers of neighbouring countries and institutions that feed their members. This indicates the existence of opportunities for farmers to exploit the market system and effectively participate in the supply chain within and across national borders. However, farmers don’t make use of this opportunity resulting from multiple constraints ranging from low production levels, low income and inconsistency in market participation to high transaction cost. It is thus relevant to identify and address the constraints facing these farmers in a bid to improve production and market participation. This analyzes the factors influencing farmer’s participation in the production and marketing of haricot beans in the Western Highlands of Cameroon.  Data was collected from 200 farmers in 24 villages in the Western Highlands of Cameroon and analyzed using descriptive and inferential statistical techniques. Findings indicate that the production and marketing of beans was dominated by older and married farmers with low educational background who depend on these for their livelihood. In addition, the farming system practiced, production season, seed type planted and access to production resources significantly influence the quantities produced and marketed. To enhance haricot beans production and marketing, the study opines that development interventions lay emphasis on infrastructural and technology improvement especially with regards to the provision and use of improved farm inputs. Keywords: Haricot beans, production, marketing, Western Highlands, Cameroo

    Primary analysis of repeat elements of the Asian seabass (Lates calcarifer) transcriptome and genome

    Get PDF
    As part of our Asian seabass genome project, we are generating an inventory of repeat elements in the genome and transcriptome. The karyotype showed a diploid number of 2n = 24 chromosomes with a variable number of B-chromosomes. The transcriptome and genome of Asian seabass were searched for repetitive elements with experimental and bioinformatics tools. Six different types of repeats constituting 8–14% of the genome were characterized. Repetitive elements were clustered in the pericentromeric heterochromatin of all chromosomes, but some of them were preferentially accumulated in pretelomeric and pericentromeric regions of several chromosomes pairs and have chromosomes specific arrangement. From the dispersed class of fish-specific non-LTR retrotransposon elements Rex1 and MAUI-like repeats were analyzed. They were wide-spread both in the genome and transcriptome, accumulated on the pericentromeric and peritelomeric areas of all chromosomes. Every analyzed repeat was represented in the Asian seabass transcriptome, some showed differential expression between the gonads. The other group of repeats analyzed belongs to the rRNA multigene family. FISH signal for 5S rDNA was located on a single pair of chromosomes, whereas that for 18S rDNA was found on two pairs. A BAC-derived contig containing rDNA was sequenced and assembled into a scaffold containing incomplete fragments of 18S rDNA. Their assembly and chromosomal position revealed that this part of Asian seabass genome is extremely rich in repeats containing evolutionarily conserved and novel sequences. In summary, transcriptome assemblies and cDNA data are suitable for the identification of repetitive DNA from unknown genomes and for comparative investigation of conserved elements between teleosts and other vertebrates

    Cross-national study of communal attitudes toward individuals with intellectual disabilities in sub-Saharan Africa : Cameroon vs. Ghana

    Get PDF
    Background: An intellectual disability (ID) is characterized by a deficit in the functional, cognitive, and adaptive skills required for independent living. Due to the low cognitive capabilities of individuals with IDs, they have become victims of marginalization, exclusion, and denial of their fundamental rights to basic necessities in societies around the world. While efforts are being made to improve service provision to and acceptance of individuals with disabilities, the extent of communal acceptance and recognition of these individuals as equal members of society remains underexplored in sub-Saharan African countries such as Cameroon and Ghana. Objective: As attitudes toward individuals with IDs are pivotal in shaping national policies, this cross-national study examined communal attitudes toward persons with IDs in Cameroon and Ghana. Method: The Community Living Attitude Scale for Intellectual Disabilities (CLAS-ID) was used to collect data from a total of 741 university students in the two countries. The validity of the scale was assessed using confirmatory factor analysis and principal component analysis. The association between the background variables and attitudes was examined using t-tests, analysis of variance, linear regression, and two-way factor analysis. Results: The results showed the validity of the CLAS-ID as a valid tool for measuring communal attitudes toward individuals with IDs in sub-Saharan Africa. The participants appeared ambivalent about attitude towards individuals with ID and other findings showed no association between attitudes and variables such as gender, relation, and contact with individuals with IDs. Conclusion: We discuss the need for innovative approaches aimed at changing attitudes toward individuals with IDs in sub-Saharan Africa as well as other study implications

    Improving diagnosis and broadening the phenotypes in early-onset seizure and severe developmental delay disorders through gene panel analysis

    Get PDF
    BACKGROUND: We sought to investigate the diagnostic yield and mutation spectrum in previously reported genes for early-onset epilepsy and disorders of severe developmental delay. METHODS: In 400 patients with these disorders with no known underlying aetiology and no major structural brain anomaly, we analysed 46 genes using a combination of targeted sequencing on an Illumina MiSeq platform and targeted, exon-level microarray copy number analysis. RESULTS: We identified causative mutations in 71/400 patients (18%). The diagnostic rate was highest among those with seizure onset within the first two months of life (39%), although overall it was similar in those with and without seizures. The most frequently mutated gene was SCN2A (11 patients, 3%). Other recurrently mutated genes included CDKL5, KCNQ2, SCN8A (six patients each), FOXG1, MECP2, SCN1A, STXBP1 (five patients each), KCNT1, PCDH19, TCF4 (three patients each) and ATP1A3, PRRT2 and SLC9A6 (two patients each). Mutations in EHMT1, GABRB3, LGI1, MBD5, PIGA, UBE3A and ZEB2 were each found in single patients. We found mutations in a number of genes in patients where either the electroclinical features or dysmorphic phenotypes were atypical for the identified gene. In only 11 cases (15%) had the clinician sufficient certainty to specify the mutated gene as the likely cause before testing. CONCLUSIONS: Our data demonstrate the considerable utility of a gene panel approach in the diagnosis of patients with early-onset epilepsy and severe developmental delay disorders., They provide further insights into the phenotypic spectrum and genotype-phenotype correlations for a number of the causative genes and emphasise the value of exon-level copy number testing in their analysis

    Nutrigenomic and nutritional analyses reveal the effects of pelleted feeds on Asian Seabass (Lates calcarifer)

    Get PDF
    As nutrition-related expenses constitute the majority of the costs for aquaculture farms, it is essential for them to use feeds that provide an ideal combination of nutrients for the species of choice. In this study, the relative effect of consuming three different pelleted feeds (B, C and D) in comparison to frozen baitfish (A; control) were compared on juvenile Asian seabass (77.3 ± 22.4g) that were selected for increased growth rate over two generations. Our objectives were: 1) to evaluate the effects of different pelleted feeds based on overall physiological changes and nutritional quality of fillets; 2) improve our understanding of the underlying mechanisms with transcriptomic analysis; 3) if possible, identify the feed type that supports the growth of these fishes without substantially reducing the nutritional quality of fillet. The growth performance, fatty acid composition of fillet, hepatic histology and transcriptome of the fishes (Groups A-D) were analyzed. The majority of fatty acids of the fillets, except γ-linolenic acid (GLA, C18:3n6), correlated significantly with the respective diets. Asian seabass fed Feed C showed highest specific growth rate (SGR) and feed conversion efficiency (FCE) with closest histology and transcriptomic profile to control, but their fillet contained the highest n6/n3 ratio. When the liver-based transcriptomes were analyzed, a complex set of differentially expressed genes were detected between groups fed pelleted feeds and controls as well as among the pellet-fed groups themselves. Significant enrichment of genes with growth-related function tallied with the morphological data measured. When compared with control (Group A), ‘Biosynthesis of unsaturated fatty acids’ and ‘Steroid biosynthesis’ pathways were significantly enriched in pellet-fed groups. Reduced goblet cell numbers were observed in the gut of pellet-fed fish compared to controls and fads6 was found to be a suitable candidate gene to separate wild-caught Asian seabass, from pellet-fed ones. These results provide insights for researchers on the various effects of feeds on the biochemistry and global gene expression of the fish and potentially for seabass farms to make more informed feed choices

    O-GlcNAc Modification of NFκB p65 Inhibits TNF-α-Induced Inflammatory Mediator Expression in Rat Aortic Smooth Muscle Cells

    Get PDF
    BACKGROUND: We have shown that glucosamine (GlcN) or O-(2-acetamido-2-deoxy-D-glucopyranosylidene)amino-N-phenylcarbamate (PUGNAc) treatment augments O-linked-N-acetylglucosamine (O-GlcNAc) protein modification and attenuates inflammatory mediator expression, leukocyte infiltration and neointima formation in balloon injured rat carotid arteries and have identified the arterial smooth muscle cell (SMC) as the target cell in the injury response. NFκB signaling has been shown to mediate the expression of inflammatory genes and neointima formation in injured arteries. Phosphorylation of the p65 subunit of NFκB is required for the transcriptional activation of NFκB. This study tested the hypothesis that GlcN or PUGNAc treatment protects vascular SMCs against tumor necrosis factor (TNF)-α induced inflammatory stress by enhancing O-GlcNAcylation and inhibiting TNF-α induced phosphorylation of NFκB p65, thus inhibiting NFκB signaling. METHODOLOGY/PRINCIPAL FINDINGS: Quiescent rat aortic SMCs were pretreated with GlcN (5 mM), PUGNAc (10(-4) M) or vehicle and then stimulated with TNF-α (10 ng/ml). Both treatments inhibited TNF-α-induced expression of chemokines [cytokine-induced neutrophil chemoattractant (CINC)-2β and monocyte chemotactic protein (MCP)-1] and adhesion molecules [vascular cell adhesion molecule (VCAM)-1 and P-Selectin]. Both treatments inhibited TNF-α induced NFκB p65 activation and promoter activity, increased NFκB p65 O-GlcNAcylation and inhibited NFκB p65 phosphorylation at Serine 536, thus promoting IκBα binding to NFκB p65. CONCLUSIONS: There is a reciprocal relationship between O-GlcNAcylation and phosphorylation of NFκB p65, such that increased NFκB p65 O-GlcNAc modification inhibits TNF-α-Induced expression of inflammatory mediators through inhibition of NFκB p65 signaling. These findings provide a mechanistic basis for our previous observations that GlcN and PUGNAc treatments inhibit inflammation and remodeling induced by acute endoluminal arterial injury

    Delineation of the movement disorders associated with FOXG1 mutations

    Get PDF
    Objective: The primary objective of this research was to characterize the movement disorders associated with FOXG1 mutations. Methods: We identified patients with FOXG1 mutations who were referred to either a tertiary movement disorder clinic or tertiary epilepsy service and retrospectively reviewed medical records, clinical investigations, neuroimaging, and available video footage. We administered a telephone-based questionnaire regarding the functional impact of the movement disorders and perceived efficacy of treatment to the caregivers of one cohort of participants. Results: We identified 28 patients with FOXG1 mutations, of whom 6 had previously unreported mutations. A wide variety of movement disorders were identified, with dystonia, choreoathetosis, and orolingual/facial dyskinesias most commonly present. Ninety-three percent of patients had a mixed movement disorder phenotype. In contrast to the phenotype classically described with FOXG1 mutations, 4 patients with missense mutations had a milder phenotype, with independent ambulation, spoken language, and normocephaly. Hyperkinetic involuntary movements were a major clinical feature in these patients. Of the symptomatic treatments targeted to control abnormal involuntary movements, most did not emerge as clearly beneficial, although 4 patients had a caregiver-reported response to levodopa. Conclusions: Abnormal involuntary movements are a major feature of FOXG1 mutations. Our study delineates the spectrum of movement disorders and confirms an expanding clinical phenotype. Symptomatic treatment may be considered for severe or disabling cases, although further research regarding potential treatment strategies is necessary

    Significant out-of-sample classification from methylation profile scoring for amyotrophic lateral sclerosis

    Get PDF
    We conducted DNA methylation association analyses using Illumina 450K data from whole blood for an Australian amyotrophic lateral sclerosis (ALS) case–control cohort (782 cases and 613 controls). Analyses used mixed linear models as implemented in the OSCA software. We found a significantly higher proportion of neutrophils in cases compared to controls which replicated in an independent cohort from the Netherlands (1159 cases and 637 controls). The OSCA MOMENT linear mixed model has been shown in simulations to best account for confounders. When combined in a methylation profile score, the 25 most-associated probes identified by MOMENT significantly classified case–control status in the Netherlands sample (area under the curve, AUC = 0.65, CI95% = [0.62–0.68], p = 8.3 × 10−22). The maximum AUC achieved was 0.69 (CI95% = [0.66–0.71], p = 4.3 × 10−34) when cell-type proportion was included in the predictor
    corecore