367 research outputs found
Using botanic gardens and arboreta to help identify urban trees for the future
Societal Impact StatementDiversification of urban forests is essential to enhance their resilience to future biotic threats as well as those posed by a changing climate. Arboreta and botanic gardens host a wide range of plant material that can be evaluated to inform tree selection policy. This study demonstrates that plant functional traits, such as the water potential at leaf turgor loss, can be highly instructive when developing evidence-based recommendations for urban environments. However, if botanic collections are to fulfil a critical role in understanding plant response to environment, they should not be managed solely as visitor attractions but must have scientific objectives at the forefront of management policy.SummaryArboreta and botanic gardens host a multitude of species that can be utilized in research focused on improving diversity within urban forests. Higher tree species diversity will enhance the resilience of urban forests to abiotic and biotic threats and help deliver strategies that foster sustainable communities. Consequently, this study aims to demonstrate the value of botanic collections as a resource for research into tree species selection for more resilient urban landscapes. As water stress is a major constraint for trees in urban environments, understanding the drought tolerance of species is essential for urban tree selection. This study evaluates a key functional trait relating to drought tolerance. Using vapor pressure osmometry, the water potential at leaf turgor loss was evaluated for 96 species using plant material from seven botanic collections in North America and Europe. Leaf turgor loss contrasted widely in the temperate deciduous trees evaluated and, in summer, ranged from -1.7 MPa to -3.9 MPa. Significant differences in drought tolerance were also apparent across genera and closely related cultivars. Osmotic adjustment was shown to be a major physiological factor driving leaf turgor loss. A meta-analysis also demonstrated that leaf turgor loss was closely related to a drought-tolerance scale based on observations of tree performance under drought. Arboreta and botanic collections can play a vital role in the evaluation of plant material for urban environments, provided they are curated with scientific objectives at the forefront of management policy and are not managed purely as visitor attractions
Extracellular superoxide dismutase (SOD3) regulates oxidative stress at the vitreoretinal interface
Oxidative stress is a pathogenic feature in vitreoretinal disease. However, the ability of the inner retina to manage metabolic waste and oxidative stress is unknown. Proteomic analysis of antioxidants in the human vitreous, the extracellular matrix opposing the inner retina, identified superoxide dismutase-3 (SOD3) that localized to a unique matrix structure in the vitreous base and cortex. To determine the role of SOD3, Sod3-/- mice underwent histological and clinical phenotyping. Although the eyes were structurally normal, at the vitreoretinal interface Sod3-/- mice demonstrated higher levels of 3-nitrotyrosine, a key marker of oxidative stress. Pattern electroretinography also showed physiological signaling abnormalities within the inner retina. Vitreous biopsies and epiretinal membranes collected from patients with diabetic vitreoretinopathy (DVR) and a mouse model of DVR showed significantly higher levels of nitrates and/or 3-nitrotyrosine oxidative stress biomarkers suggestive of SOD3 dysfunction. This study analyzes the molecular pathways that regulate oxidative stress in human vitreous substructures. The absence or dysregulation of the SOD3 antioxidant at the vitreous base and cortex results in increased oxidative stress and tissue damage to the inner retina, which may underlie DVR pathogenesis and other vitreoretinal diseases
Characteristics of Mothers Caring for Children During Episodes of Homelessness
This study provides a description of the physical, psychological, and substance use problems of adult homeless women who are and are not caring for children. We also examined differences in the characteristics of these two groups of women. Interviews were conducted with 148 homeless women from three mid-sized U.S. cities, 24.3% of whom were caring for at least one child. Our results showed that women caring for children were more likely to be sheltered and have health insurance. Homeless women caring for children and solitary homeless women were generally similar in terms of substance abuse problems. However, rates of Borderline Personality Disorder were higher among women caring for children than among solitary homeless women. Our results are somewhat consistent with previous research, with the exception of substance abuse problems and mental health problems, which were shown to be equally problematic for all women, regardless of current caregiving status
Influence of social support on cognitive function in the elderly
BACKGROUND: Social support is important in daily activities of the elderly. This study tests the hypothesis that there is an association between social support and cognitive function among the elderly in a community setting. METHODS: Face-to-face interviews were conducted in a cross-sectional stratified random sample of 4,993 elderly (≥65 years) city residents. Using multiple regression analysis, we investigated the influence of social support on cognitive function. RESULTS: 12% were over 80 years old. 53.28% were men. 67.14% were married. Higher Short Portable Mental Status Questionnaire (SPMSQ) scores (higher score means better cognitive function) were associated with strong social support, as measured by marital status and perceived positive support from friends. Lower cognitive function was associated with older and with female respondents. Only instrumental activities of daily living (IADL) were statistically and negatively related to SPMSQ. Lower functional status was associated with lower cognitive function. Elders with grade school educations had lower SPMSQ scores than did elders with high school educations. CONCLUSIONS: In Taiwan, higher cognitive function in community-living elderly was associated with increased social support. Life-style management should provide social activities for the elderly to promote a better quality of life
An international effort towards developing standards for best practices in analysis, interpretation and reporting of clinical genome sequencing results in the CLARITY Challenge
BACKGROUND: There is tremendous potential for genome sequencing to improve clinical diagnosis and care once it becomes routinely accessible, but this will require formalizing research methods into clinical best practices in the areas of sequence data generation, analysis, interpretation and reporting. The CLARITY Challenge was designed to spur convergence in methods for diagnosing genetic disease starting from clinical case history and genome sequencing data. DNA samples were obtained from three families with heritable genetic disorders and genomic sequence data was donated by sequencing platform vendors. The challenge was to analyze and interpret these data with the goals of identifying disease causing variants and reporting the findings in a clinically useful format. Participating contestant groups were solicited broadly, and an independent panel of judges evaluated their performance. RESULTS: A total of 30 international groups were engaged. The entries reveal a general convergence of practices on most elements of the analysis and interpretation process. However, even given this commonality of approach, only two groups identified the consensus candidate variants in all disease cases, demonstrating a need for consistent fine-tuning of the generally accepted methods. There was greater diversity of the final clinical report content and in the patient consenting process, demonstrating that these areas require additional exploration and standardization. CONCLUSIONS: The CLARITY Challenge provides a comprehensive assessment of current practices for using genome sequencing to diagnose and report genetic diseases. There is remarkable convergence in bioinformatic techniques, but medical interpretation and reporting are areas that require further development by many groups
A missense mutation in the MLKL brace region promotes lethal neonatal inflammation and hematopoietic dysfunction
MLKL is the essential effector of necroptosis, a form of programmed lytic cell death. We have isolated a mouse strain with a single missense mutation, Mlkl(D139V), that alters the two-helix 'brace' that connects the killer four-helix bundle and regulatory pseudokinase domains. This confers constitutive, RIPK3 independent killing activity to MLKL. Homozygous mutant mice develop lethal postnatal inflammation of the salivary glands and mediastinum. The normal embryonic development of Mlkl(D139V) homozygotes until birth, and the absence of any overt phenotype in heterozygotes provides important in vivo precedent for the capacity of cells to clear activated MLKL. These observations offer an important insight into the potential disease-modulating roles of three common human MLKL polymorphisms that encode amino acid substitutions within or adjacent to the brace region. Compound heterozygosity of these variants is found at up to 12-fold the expected frequency in patients that suffer from a pediatric autoinflammatory disease, chronic recurrent multifocal osteomyelitis (CRMO). Necroptosis is a regulated form of inflammatory cell death driven by activated MLKL. Here, the authors identify a mutation in the brace region that confers constitutive activation, leading to lethal inflammation in homozygous mutant mice and providing insight into human mutations in this region
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