63 resultados para Leaf traits
Resumo:
The role of genetics in parkinsonism has been confirmed over the last decade with the identification of genetic variation in seven genes, which are causative in familial forms of the disorder. A number of pathogenic mutations have been identified in the latest gene LRRK2, with a Gly2019Ser amino acid substitution identified in two siblings and one patient with idiopathic Parkinson's disease from Ireland. The clinical features resemble the idiopathic variant with a tremor predominant clinical picture shared by the siblings, slow progression of symptoms, and no observation of cognitive disturbance in all. The family and the sporadic individual were apparently not related and originated from different regions of Ireland, although haplotype analysis does suggest they share a common founder. The influence of the G2019S substitution on protein function and disease phenotype has yet to be fully resolved, but its elucidation will undoubtedly further our understanding of the mechanisms underlying Parkinson's disease.
Resumo:
The relative resistance of 15 winter barley, three winter wheat and three winter oat cultivars on the UK recommended list 2003 and two spring wheat cultivars on the Irish 2003 recommended list were evaluated using Microdochium nivale in detached leaf assays to further understand components of partial disease resistance (PDR) and Fusarium head blight (FHB) resistance across cereal species. Barley cultivars showed incubation periods comparable to, and latent periods longer than the most FHB resistant Irish and UK wheat cultivars evaluated. In addition, lesions on barley differed from those on wheat as they were not visibly chlorotic when placed over a light box until sporulation occurred, in contrast to wheat cultivars where chlorosis of the infected area occurred when lesions first developed. The pattern of delayed chlorosis of the infected leaf tissue and longer latent periods indicate that resistances are expressed in barley after the incubation period is observed, and that these temporarily arrest the development of mycelium and sporulation. Incubation periods were longer for oats compared to barley or wheat cultivars. However, oat cultivars differed from both wheat and barley in that mycelial growth was observed before obvious tissue damage was detected under macroscopic examination, indicating tolerance of infection rather than inhibition of pathogen development, and morphology of sporodochia differed, appearing less well developed and being much less abundant. Longer latent periods have previously been related to greater FHB resistance in wheat. The present results suggest the longer latent periods of barley and oat cultivars, than wheat, are likely to play a role in overall FHB resistance if under the same genetic control as PDR components expressed in the head. However the limited range of incubation and latent periods observed within barley and oat cultivars evaluated was in contrast with wheat where incubation and latent periods were shorter and more variable among genotypes. The significance of the various combinations of PDR components detected in the detached leaf assay as components of FHB resistance in each crop requires further investigation, particularly with regard to the apparent tolerance of infection in oats and necrosis in barley, after the incubation period is observed, associated with retardation of mycelial growth and sporulation.
Resumo:
Primary objective: To compare patients with traumatic brain injury (TBI) with controls on sub-types of aggression and explore the role of social desirability.
Design: Quasi-experimental, matched-participants design.
Methods and procedures: Sixty-nine participants were included in the study. The sample comprised a TBI group (n = 24), a spinal cord injury (SCI) group (n = 21) and an uninjured (UI) group of matched healthy volunteers (n = 24). Participants were given self-report measures of aggression, social desirability and impulsivity. Sixty-one independent ‘other-raters’ were nominated, who rated participant pre-morbid and post-morbid aggression.
Main outcomes and results: Using standardized norms, 25–39% of participants with TBI were classified as high average–very high on anger and 35–38% as high average–very high on verbal aggression. Other-raters rated participants with TBI as significantly higher on verbal aggression than SCI and UI participants. There were no differences between the groups on physical aggression. The TBI group also had higher levels of impulsivity than SCI and UI groups. Social desirability was a highly significant predictor of self-reported aggression for the entire sample.
Conclusions: Impulsive verbal aggression and anger are the principal aggressive traits after brain injury. Physical aggression may present in extreme cases after TBI, but appears less prominent overall in this population. Social desirability, previously overlooked in research examining TBI aggression, emerged as an influential variable that should be considered in future TBI research.
Resumo:
The defensive strategy of amphibians against predator attack relies heavily on the secretion of noxious/toxic chemical cocktails from specialized skin granular glands. Bioactive peptides constitute a major component of secretions in many species and the most complex are produced by neotropical leaf frogs of the sub-family Phyllomedusinae. We recently reported that these skin secretions contain elements of both the granular gland peptidome and transcriptome and that polyadenylated mRNAs constituting the latter are protected from degradation by interactions with endogenous amphipathic peptides. This thus permits parallel amino acid sequencing of peptides and nucleic acid sequencing of cloned precursor transcripts from single lyophilized samples of secretion. Here we report that the protection afforded is sufficiently robust to permit transcriptome studies by cloning of full-length polyadenylated peptide precursor encoding mRNAs from libraries constructed using ambient temperature air-dried skin from recently deceased specimens as source material. The technique was sufficiently sensitive to permit the identification of cDNAs encoding antimicrobial peptides constituted by six different isoforms of phylloseptin and two dermaseptins. Also, for the first time, establishment of the nucleic acid and amino acid sequence of the precursor encoding the phyllomedusine frog skin bradykinin-related peptide, phyllokinin, from cloned cDNA, was achieved. These data unequivocally demonstrate that the granular gland transcriptome persists in air-dried amphibian skin—a finding that may have fundamental implications in the study of archived materials but also in the wider field of molecular biology.
Resumo:
The Chinese bamboo leaf odorous frog (Rana (Odorrana) versabilis) and the North American pickerel frog (Rana palustris) occupy different ecological niches on two different continents with no overlap in geographical distribution. R. palustris skin secretions contain a formidable array of antimicrobial peptides including homologs of brevinin-1, esculentin-1, esculentin-2, ranatuerin-2, a temporin and a family of peptides considered of unique structural attributes when isolated, palustrins 1–3. Here we describe the structures of mature peptides and precursors of eight putative antimicrobial peptides from the skin secretion of the Chinese bamboo leaf odorous frog (Rana (Odorrana) versabilis). Each peptide represents a structural homolog of respective peptide families isolated from R. palustris, including two peptides identical in primary structure to palustrin 1c and palustrin 3b. Additionally, two peptides were found to be structural homologs of ranatuerin 2B and ranatuerin 2P from the closely-related North American species, Rana berlandieri (the Rio Grande leopard frog) and Rana pipiens (the Northern leopard frog), respectively. Both palustrins and ranatuerins have hitherto been considered unique to North American ranid frogs. The use of primary structures of amphibian skin antimicrobial peptides is thus questionable as a taxonomic device or alternatively, the micro-evolution and/or ancestry of ranid frogs is more highly complex than previously thought.