92 research outputs found
Plants and vegetation of NW Ethiopia
Pichi Sermolli’s work with his more than 2750 collections of plants from nearly 150 localities on the Lake Tana expedition in Ethiopia in 1937 was interrupted by World War II, but completed in 1947 at the Royal Botanic Gardens, Kew, and the British Museum (Natural History), UK. It resulted in preliminary accounts of the vegetation published 1938-40 and a taxonomically arranged account in 1951, all in Italian. Pichi Sermolli’s observations are difficult to locate due to the imperfect maps of the time, but in this book the authors have reconstructed the sequence of the collections, georeferenced the localities, and updated the identifications of the species. By reconstructing Pichi Sermolli’s observations, it is possible to draw conclusions about the vegetation and compare with a recent model of the vegetation of Ethiopia. According to this, the vegetation of the Lake Tana Basin was a complex mosaic of woodland, scrub, forest, farmland and lake shore vegetation now difficult to interpret in detail. Pichi Sermolli’s study of the vegetation in the Semien Mountains demonstrated for the first time the zonation of Ericaceous woodland and Afroalpine vegetation, within which he distinguished Carex monostachya bogs, Afroalpine grasslands with Lobelia rhynchopetalum, and stony and rocky Afroalpine vegetation. This book interprets Pichi Sermolli’s observations in English and compares them with modern knowledge of the region, partly obtained by the present authors’ own field work. It demonstrates how Pichi Sermolli’s studies form a valuable contribution to the understanding of the Ethiopian flora and vegetation
Plants and vegetation of NW Ethiopia
Pichi Sermolli’s work with his more than 2750 collections of plants from nearly 150 localities on the Lake Tana expedition in Ethiopia in 1937 was interrupted by World War II, but completed in 1947 at the Royal Botanic Gardens, Kew, and the British Museum (Natural History), UK. It resulted in preliminary accounts of the vegetation published 1938-40 and a taxonomically arranged account in 1951, all in Italian. Pichi Sermolli’s observations are difficult to locate due to the imperfect maps of the time, but in this book the authors have reconstructed the sequence of the collections, georeferenced the localities, and updated the identifications of the species. By reconstructing Pichi Sermolli’s observations, it is possible to draw conclusions about the vegetation and compare with a recent model of the vegetation of Ethiopia. According to this, the vegetation of the Lake Tana Basin was a complex mosaic of woodland, scrub, forest, farmland and lake shore vegetation now difficult to interpret in detail. Pichi Sermolli’s study of the vegetation in the Semien Mountains demonstrated for the first time the zonation of Ericaceous woodland and Afroalpine vegetation, within which he distinguished Carex monostachya bogs, Afroalpine grasslands with Lobelia rhynchopetalum, and stony and rocky Afroalpine vegetation. This book interprets Pichi Sermolli’s observations in English and compares them with modern knowledge of the region, partly obtained by the present authors’ own field work. It demonstrates how Pichi Sermolli’s studies form a valuable contribution to the understanding of the Ethiopian flora and vegetation
Dioscorea orangeana (Dioscoreaceae), a new and threatened species of edible yam from northern Madagascar
International audienceA new species of yam (Dioscorea orangeana Wilkin) is described and illustrated. It differs from D. comorensis R.Knuth by having undulate leaf margins and a broader torus and tepals in both the male and female flowers. In female flowers of D. orangeana the floral stipe between the ovary and the torus is shorter than in D. comorensis. The tuber morphology of the species is atypical among Malagasy species in that there are several digitate lobes rather than a single tuber per growing season, although more research is needed on tuber morphology. D. orangeana is reported to be edible. It is endemic to the Forêt d'Orangea near Diego Suarez (Antsiranana) in Antsiranana Préfecture. Its conservation and sustainable use are thus matters of concern
Correction by the ercc2 gene of UV sensitivity and repair deficiency phenotype in a subset of trichothiodystrophy cells
Trichothiodystrophy (TTD) is a rare genetic disease with heterogeneous clinical features associated with specific deficiencies in nucleotide excision repair. Patients have brittle hair due to a reduced content of cysteine-rich matrix proteins. About 50% of the cases reported in the literature are photosensitive. In these patients an altered cellular response to UV, due to a specific deficiency in nucleotide excision repair, has been observed. The majority of repairdefective TTD patients have been assigned by complementation analysis to group D of xeroderma pigmentosum (XP). Recently, the human excision repair gene ERCC2 has been shown to correct the UV sensitivity of XP-D fibroblasts. In this work we describe the effect of ERCC2 on the DNA repair deficient phenotype of XP-D and on two repair-defective TTD cell strains (TTD1VI and TTD2VI) assigned by complementation analysis to group D of XP. ERCC2 cDNA, cloned into a mammalian expression vector, was introduced into TTD and XP fibroblasts via DNA-mediated transfection or microneedle injection. UV sensitivity and cellular DNA repair properties, including unscheduled DNA synthesis and reactivation of a UVirradiated plasmid containing the chloramphenicol acetyltransferase reporter gene (pRSVCat), were corrected to wild-type levels in both TTD and XP-D cells. These data show that a functional ERCC2 gene is sufficient to reestablish a wild-type DNA repair phenotype in TTD1VI and TTD2VI cells, confirming the genetic relationship between TTD and XP-D. Furthermore, our findings suggest that mutations at the ERCC2 locus are responsible for causing a similar phenotype in TTD and XP-D cells in response to UV irradiation, but produce quite different clinical symptorns.</p
Correction by the ercc2 gene of UV sensitivity and repair deficiency phenotype in a subset of trichothiodystrophy cells
Trichothiodystrophy (TTD) is a rare genetic disease with heterogeneous clinical features associated with specific deficiencies in nucleotide excision repair. Patients have brittle hair due to a reduced content of cysteine-rich matrix proteins. About 50% of the cases reported in the literature are photosensitive. In these patients an altered cellular response to UV, due to a specific deficiency in nucleotide excision repair, has been observed. The majority of repairdefective TTD patients have been assigned by complementation analysis to group D of xeroderma pigmentosum (XP). Recently, the human excision repair gene ERCC2 has been shown to correct the UV sensitivity of XP-D fibroblasts. In this work we describe the effect of ERCC2 on the DNA repair deficient phenotype of XP-D and on two repair-defective TTD cell strains (TTD1VI and TTD2VI) assigned by complementation analysis to group D of XP. ERCC2 cDNA, cloned into a mammalian expression vector, was introduced into TTD and XP fibroblasts via DNA-mediated transfection or microneedle injection. UV sensitivity and cellular DNA repair properties, including unscheduled DNA synthesis and reactivation of a UVirradiated plasmid containing the chloramphenicol acetyltransferase reporter gene (pRSVCat), were corrected to wild-type levels in both TTD and XP-D cells. These data show that a functional ERCC2 gene is sufficient to reestablish a wild-type DNA repair phenotype in TTD1VI and TTD2VI cells, confirming the genetic relationship between TTD and XP-D. Furthermore, our findings suggest that mutations at the ERCC2 locus are responsible for causing a similar phenotype in TTD and XP-D cells in response to UV irradiation, but produce quite different clinical symptorns.</p
Quantification of stochastic noise of splicing and polyadenylation in Entamoeba histolytica
Alternative splicing and polyadenylation were observed pervasively in eukaryotic messenger RNAs. These alternative isoforms could either be consequences of physiological regulation or stochastic noise of RNA processing. To quantify the extent of stochastic noise in splicing and polyadenylation, we analyzed the alternative usage of splicing and polyadenylation sites in Entamoeba histolytica using RNA-Seq. First, we identified a large number of rarely spliced alternative junctions and then showed that the occurrence of these alternative splicing events is correlated with splicing site sequence, occurrence of constitutive splicing events and messenger RNA abundance. Our results implied the majority of these alternative splicing events are likely to be stochastic error of splicing machineries, and we estimated the corresponding error rates. Second, we observed extensive microheterogeneity of polyadenylation cleavage sites, and the extent of such microheterogeneity is correlated with the occurrence of constitutive cleavage events, suggesting most of such microheterogeneity is likely to be stochastic. Overall, we only observed a small fraction of alternative splicing and polyadenylation isoforms that are unlikely to be solely stochastic, implying the functional relevance of alternative splicing and polyadenylation in E. histolytica is limited. Lastly, we revised the gene models and annotated their 3′UTR in AmoebaDB, providing valuable resources to the community
Zinc-gallium oxynitride powders: effect of the oxide precursor synthesis route
International audienceZinc-gallium oxynitride powders (ZnGaON) were synthesized by nitridation of ZnGa2O4 oxide precursor obtained by polymeric precursors (PP) and solid state reaction (SSR) methods and the influence of the synthesis route of ZnGa2O4 on the final compound ZnGaON was investigated. Crystalline single phase ZnGa2O4 was obtained at 1100 oC / 12 h by SSR and at 600 oC / 2 h by PP with different grain sizes and specific surface areas according to the synthesis route. After nitridation, ZnGaON oxynitrides with a GaN würtzite-type structure were obtained in both cases, however at lower temperatures for PP samples. The microstructure and the specific surface area were strongly dependent on the oxide synthesis method and on the nitridation temperature (42 m2g-1 and 5 m2g-1 for PP and SSR oxides treated at 700 °C, respectively). The composition analyses showed a strong loss of Zn for the PP samples, favored by the increase of ammonolysis temperature and by the higher specific surface area
Triheptanoin Did Not Show Benefit versus Placebo for the Treatment of Paroxysmal Movement Disorders in Glut1 Deficiency Syndrome: Results of a Randomized Phase 3 Study
BACKGROUND: Paroxysmal movement disorders are common in Glut1 deficiency syndrome (Glut1DS). Not all patients respond to or tolerate ketogenic diets. OBJECTIVES: The objective was to evaluate the effectiveness and safety of triheptanoin in reducing the frequency of disabling movement disorders in patients with Glut1DS not receiving a ketogenic diet. METHODS: UX007G-CL301 was a randomized, double-blind, placebo-controlled, phase 3 crossover study. After a 6-week run-in, eligible patients were randomized 1:1 to the first sequence (triheptanoin/placebo or placebo/triheptanoin) titration plus maintenance, followed by washout and the opposite sequence titration plus maintenance. The placebo (safflower oil) matched the appearance, taste, and smell of triheptanoin. Open-label triheptanoin was administered in the extension. The frequency of disabling paroxysmal movement disorder events per 4 weeks (recorded by diary during maintenance; primary endpoint) was assessed by Wilcoxon rank-sum test. RESULTS: Forty-three patients (children, n = 16; adults, n = 27) were randomized and treated. There was no difference between triheptanoin and placebo in the mean (interquartile range) number of disabling paroxysmal movement disorder events (14.3 [4.7-38.3] vs. 11.8; [3.2-28.7]; Hodges-Lehmann estimated median difference: 1.46; 95% confidence interval, -1.12 to 4.36; P = 0.2684). Treatment-emergent adverse events were mild/moderate in severity and included diarrhea, vomiting, upper abdominal pain, headache, and nausea. Two patients discontinued the study because of non-serious adverse events that were predominantly gastrointestinal. The study was closed early during the open-label extension because of lack of effectiveness. Seven patients continued to receive triheptanoin compassionately. CONCLUSION: There were no significant differences between the triheptanoin and placebo groups in the frequency of disabling movement disorder events during the double-blind maintenance period. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
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