97 research outputs found

    Experimental warming differentially affects vegetative and reproductive phenology of tundra plants

    Get PDF
    Rapid climate warming is altering Arctic and alpine tundra ecosystem structure and function, including shifts in plant phenology. While the advancement of green up and flowering are well-documented, it remains unclear whether all phenophases, particularly those later in the season, will shift in unison or respond divergently to warming. Here, we present the largest synthesis to our knowledge of experimental warming effects on tundra plant phenology from the International Tundra Experiment. We examine the effect of warming on a suite of season-wide plant phenophases. Results challenge the expectation that all phenophases will advance in unison to warming. Instead, we find that experimental warming caused: (1) larger phenological shifts in reproductive versus vegetative phenophases and (2) advanced reproductive phenophases and green up but delayed leaf senescence which translated to a lengthening of the growing season by approximately 3%. Patterns were consistent across sites, plant species and over time. The advancement of reproductive seasons and lengthening of growing seasons may have significant consequences for trophic interactions and ecosystem function across the tundra.publishedVersio

    AXL/MERTK inhibitor ONO-7475 potently synergizes with venetoclax and overcomes venetoclax resistance to kill <i>FLT3</i>-ITD acute myeloid leukemia

    Get PDF
    FMS-like Tyrosine Kinase 3 (FLT3) mutation is associated with poor survival in acute myeloid leukemia (AML). The specific Anexelekto/MER Tyrosine Kinase (AXL) inhibitor, ONO-7475, kills FLT3-mutant AML cells with targets including Extracellular- signal Regulated Kinase (ERK) and Myeloid Cell Leukemia 1 (MCL1). ERK and MCL1 are known resistance factors for Venetoclax (ABT-199), a popular drug for AML therapy, prompting the investigation of the efficacy of ONO-7475 in combination with ABT-199 in vitro and in vivo. ONO-7475 synergizes with ABT-199 to potently kill FLT3-mutant acute myeloid leukemia cell lines and primary cells. ONO-7475 is effective against ABT-199-resistant cells including cells that overexpress MCL1. Proteomic analyses revealed that ABT-199-resistant cells expressed elevated levels of pro-growth and anti-apoptotic proteins compared to parental cells, and that ONO-7475 reduced the expression of these proteins in both the parental and ABT-199-resistant cells. ONO-7475 treatment significantly extended survival as a single in vivo agent using acute myeloid leukemia cell lines and PDX models. Compared to ONO-7474 monotherapy, the combination of ONO-7475/ABT-199 was even more potent in reducing leukemic burden and prolonging the survival of mice in both model systems. These results suggest that the ONO-7475/ABT-199 combination may be effective for AML therapy

    The tundra phenology database: more than two decades of tundra phenology responses to climate change

    Get PDF
    Observations of changes in phenology have provided some of the strongest signals of the effects of climate change on terrestrial ecosystems. The International Tundra Experiment (ITEX), initiated in the early 1990s, established a common protocol to measure plant phenology in tundra study areas across the globe. Today, this valuable collection of phenology measurements depicts the responses of plants at the colder extremes of our planet to experimental and ambient changes in temperature over the past decades. The database contains 150 434 phenology observations of 278 plant species taken at 28 study areas for periods of 1\u201326 years. Here we describe the full data set to increase the visibility and use of these data in global analyses and to invite phenology data contributions from underrepresented tundra locations. Portions of this tundra phenology database have been used in three recent syntheses, some data sets are expanded, others are from entirely new study areas, and the entirety of these data are now available at the Polar Data Catalogue (https://doi.org/10.21963/13215)

    Investigating the influence of youth hockey specialization on psychological needs (dis)satisfaction, mental health, and mental illness

    Full text link
    The Developmental Model of Sport Participation describes three pathways that youth can follow: recreational participation, late specialization and early specialization. Many competitive sport programmes are promoting early specialization in hopes that their athletes will gain an advantage over others; however, research indicates that youth who wait until adolescence to specialize in a given sport may achieve physical and psychological benefits. The purpose of this study was to investigate the psychological effects of sport specialization by examining relationships between youth hockey players’ level of specialization, psychological needs satisfaction (PNS), psychological needs dissatisfaction (PND), mental health and mental illness. Sixty-one youth male hockey players (Mage = 14.90) responded to an online survey. Results indicated that PND according to specialization was significant with early specializers reporting the highest PND and recreational athletes reporting the lowest PND (p = .029), indicating a large effect size (η2 = .157). No other significant differences were found. Bivariate correlations revealed significant relationships between all variables. Moreover, regression analyses showed that PNS positively predicted mental health (β = .47) and negatively predicted mental illness (β = −.51), while PND positively predicted mental illness (β = .71) and negatively predicted mental health (β = −.44). Results suggest that PNS is important to promote mental health and avoid mental illness. Future research is needed to fully understand the psychological consequences of early sport specialization

    Understanding How Organized Youth Sport May Be Harming Individual Players within the Family Unit: A Literature Review

    Full text link
    Within the United States, close to 45 million youths between the ages of 6 and 18 participate in some form of organized sports. While recent reviews have shown the positive effects of youth sport participation on youth health, there are also several negative factors surrounding the youth sport environment. To date, a comprehensive review of the negative physical and psychological effects of organized sport on youth has not been done and little thus far has documented the effect organized sport has on other players within a family, particularly on parents and siblings. Therefore the purpose of this paper is to conduct a review of studies on the negative effects of organized sport on the youth athlete and their parents and siblings. Articles were found by searching multiple databases (Physical Education Index and Sociology, Psychology databases (Proquest), SPORTDiscus and Health, History, Management databases (EBSCOhost), Science, Social Science, Arts and Humanities on Web of Science (ISI), SCOPUS and Scirus (Elsevier). Results show the darker side of organized sport for actors within the family unit. A model is proposed to explain under which circumstances sport leads to positive versus negative outcomes, ideas for future research are drawn and recommendations are made to optimize the youth sport experience and family health
    corecore