870 research outputs found

    Leaves of more cold hardy grapes have a higher density of small, sunken stomata

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    Leaf stomatal density, index and size are known to be affected by the growing conditions, presumably to provide a better function for plant development. The question was whether there is a difference in stomatal parameters between grape species with different cold hardiness: V. riparia and V. vinifera; and the V. vinifera cultivars 'Riesling', 'Chardonnay', 'Sauvignon Blanc' and 'Merlot'. Analysis by scanning electron microscopy allowed the observation of 3 types of stomata in developing and mature leaves of all examined grape leaves. Stomatal parameters were found to be significantly affected by species or cultivar and growing conditions but not rootstock. A higher stomatal density and index were determined for the more cold hardy V. riparia and V. vinifera 'Riesling', whereby the higher number of stomata in 'Riesling' was found to be due to a higher number of small, sunken stomata. These findings might indicate a strategy of grape plants to optimize growth under low temperatures by using fast-acting stomata whose gas and water exchange are less affected than for larger stomata

    Identification, analysis, and linkage mapping of expressed sequence tags from the Australian sheep blowfly

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    Background: The Australian sheep blowfly Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae) is a destructive pest of the sheep, a model organism for insecticide resistance research, and a valuable tool for medical and forensic professionals. However, genomic information on L. cuprina is still sparse.Results: We report here the construction of an embryonic and 2 larval cDNA libraries for L. cuprina. A total of 29,816 expressed sequence tags (ESTs) were obtained and assembled into 7,464 unique clusters. The sequence collection captures a great diversity of genes, including those related to insecticide resistance (e.g., 12 cytochrome P450s, 2 glutathione S transferases, and 6 esterases). Compared to Drosophila melanogaster, codon preference is different in 13 of the 18 amino acids encoded by redundant codons, reflecting the lower overall GC content in L. cuprina. In addition, we demonstrated that the ESTs could be converted into informative gene markers by capitalizing on the known gene structures in the model organism D. melanogaster. We successfully assigned 41 genes to their respective chromosomes in L. cuprina. The relative locations of these loci revealed high but incomplete chromosomal synteny between L. cuprina and D. melanogaster.Conclusions: Our results represent the first major transcriptomic undertaking in L. cuprina. These new genetic resources could be useful for the blowfly and insect research community

    Parent Attitudes Towards Predictive Testing for Autism in the First Year of Life

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    Abstract Background Emerging biomarker technologies (e.g., MRI, EEG, digital phenotyping, eye-tracking) have potential to move the identification of autism into the first year of life. We investigated the perspectives of parents about the anticipated utility and impact of predicting later autism diagnosis from a biomarker-based test in infancy. Methods Parents of infants were interviewed to ascertain receptiveness and perspectives on early (6-12 months) prediction of autism using emerging biomarker technologies. One group had experience parenting an older autistic child (n=30), and the other had no prior autism parenting experience (n=25). Parent responses were analyzed using inductive qualitative coding methods. Results Almost all parents in both groups were interested in predictive testing for autism, with some stating they would seek testing only if concerned about their infant’s development. The primary anticipated advantage of testing was to enable access to earlier intervention. Parents also described the anticipated emotions they would feel in response to test results, actions they might take upon learning their infant was likely to develop autism, attitudes towards predicting a child’s future support needs, and the potential impacts of inaccurate prediction. Conclusion In qualitative interviews, parents of infants with and without prior autism experience shared their anticipated motivations and concerns about predictive testing for autism in the first year of life. The primary reported motivators for testing—to have more time to prepare and intervene early—could be constrained by familial resources and service availability. Implications for ethical communication of results, equitable early intervention, and future research are discussed

    Evaluating the impact of a year-long external mentorship pilot program in classical hematology

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    Effective mentorship is a pivotal factor in shaping the career trajectory of trainees interested in classical hematology (CH), which is of critical importance due to the anticipated decline in the CH workforce. However, there is a lack of mentorship opportunities within CH compared with medical oncology. To address this need, a year-long external mentorship program was implemented through the American Society of Hematology Medical Educators Institute. Thirty-five hematology/oncology fellows interested in CH and 34 academically productive faculty mentors from different institutions across North America were paired in a meticulous process that considered individual interests, experiences, and background. Pairs were expected to meet virtually once a month. Participation in a scholarly project was optional. A mixed-methods sequential explanatory design was used to evaluate the program using mentee and mentor surveys, a mentee interview, and a mentee focus group. Thirty-three mentee-mentor pairs (94.2%) completed the program. Sixty-three percent of mentee respondents worked on a scholarly project with their mentor; several mentees earned publications, grants, and awards. Mentee perception that their assigned mentor was a good match was associated with a perceived positive impact on confidence (P = .0423), career development (P = .0423), and professional identity (P = .0302). Furthermore, 23 mentees (66%) accepted CH faculty positions after fellowship. All mentor respondents believed that this program would increase retention in CH. This mentorship program demonstrates a productive, beneficial way of connecting mentees and mentors from different institutions to improve the careers of CH trainees, with the ultimate goal of increasing retention in CH

    Enhanced firing of locus coeruleus neurons and SK channel dysfunction are conserved in distinct models of prodromal Parkinson's disease

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    Parkinson’s disease (PD) is clinically defined by the presence of the cardinal motor symptoms, which are associated with a loss of dopaminergic nigrostriatal neurons in the substantia nigra pars compacta (SNpc). While SNpc neurons serve as the prototypical cell-type to study cellular vulnerability in PD, there is an unmet need to extent our efforts to other neurons at risk. The noradrenergic locus coeruleus (LC) represents one of the first brain structures affected in Parkinson’s disease (PD) and plays not only a crucial role for the evolving non-motor symptomatology, but it is also believed to contribute to disease progression by efferent noradrenergic deficiency. Therefore, we sought to characterize the electrophysiological properties of LC neurons in two distinct PD models: (1) in an in vivo mouse model of focal α-synuclein overexpression; and (2) in an in vitro rotenone-induced PD model. Despite the fundamental differences of these two PD models, α-synuclein overexpression as well as rotenone exposure led to an accelerated autonomous pacemaker frequency of LC neurons, accompanied by severe alterations of the afterhyperpolarization amplitude. On the mechanistic side, we suggest that Ca(2+)-activated K(+) (SK) channels are mediators of the increased LC neuronal excitability, as pharmacological activation of these channels is sufficient to prevent increased LC pacemaking and subsequent neuronal loss in the LC following in vitro rotenone exposure. These findings suggest a role of SK channels in PD by linking α-synuclein- and rotenone-induced changes in LC firing rate to SK channel dysfunction
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