TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Zidovudine in persons with asymptomatic HIV infection and CD4+ cell counts greater than 400 per cubic millimeter

Background: Zidovudine therapy is of benefit in the treatment of symptomatic and asymptomatic human immunodeficiency virus (HIV) infection in persons with CD4+ cell counts of less than 500 per cubic millimeter. The efficacy, safety, and duration of benefit of zidovudine in those with 500 or more CD4+ cells per cubic millimeter are uncertain. Methods: In a double-blind, placebo-controlled trial, 993 patients with asymptomatic HIV infection and CD4+ cell counts above 400 per cubic millimeter were randomly assigned to receive zidovudine (500 mg twice daily) or placebo for three years. The primary end point was progression of disease, as defined by the development of Centers for Disease Control and Prevention (CDC) group IV disease (including recurrent oral candidiasis, hairy leukoplakia, or progressive diarrhea) or two CD4+ cell counts below 350 per cubic millimeter. This outcome measure was changed from the original end point of the acquired immunodeficiency syndrome (AIDS) or advanced AIDS-related complex to reflect changes in recommendations for management. The study was terminated after the first interim analysis. Results: Disease progression was significantly less frequent in the zidovudine group (relative risk, 0.56; 95 percent confidence interval, 0.43 to 0.75; P<0.001 by the log-rank test). The probability of disease progression at two years was 0.19 with zidovudine, as compared with 0.34 with placebo (95 percent confidence interval for the difference, -0.21 to -0.08). Progression to CDC group IV disease was reduced by half in the zidovudine recipients (relative risk, 0.49; P = 0.049) and decline in CD4+ cell counts to below 350 per cubic millimeter was reduced by 40 percent (relative risk, 0.60; P<0.001). The inclusion of early HIV disease events (oral candidiasis, oral hairy leukoplakia, and herpes zoster) as end points confirmed the effects of zidovudine on the progression of clinical disease (relative risk, 0.55; 95 percent confidence interval, 0.37 to 0.84; P = 0.004). The median duration of treatment was 94 weeks. Severe hematologic or clinical side effects were rare. Conclusions: Treatment with zidovudine benefits HIV-infected persons with CD4+ cell counts above 400 per cubic millimeter. Despite the use of doses larger than those now generally prescribed, zidovudine was well tolerated for up to three years by most of our patients

Zidovudine in persons with asymptomatic HIV infection and CD4+ cell counts greater than 400 per cubic millimeter

Background: Zidovudine therapy is of benefit in the treatment of symptomatic and asymptomatic human immunodeficiency virus (HIV) infection in persons with CD4+ cell counts of less than 500 per cubic millimeter. The efficacy, safety, and duration of benefit of zidovudine in those with 500 or more CD4+ cells per cubic millimeter are uncertain. Methods: In a double-blind, placebo-controlled trial, 993 patients with asymptomatic HIV infection and CD4+ cell counts above 400 per cubic millimeter were randomly assigned to receive zidovudine (500 mg twice daily) or placebo for three years. The primary end point was progression of disease, as defined by the development of Centers for Disease Control and Prevention (CDC) group IV disease (including recurrent oral candidiasis, hairy leukoplakia, or progressive diarrhea) or two CD4+ cell counts below 350 per cubic millimeter. This outcome measure was changed from the original end point of the acquired immunodeficiency syndrome (AIDS) or advanced AIDS-related complex to reflect changes in recommendations for management. The study was terminated after the first interim analysis. Results: Disease progression was significantly less frequent in the zidovudine group (relative risk, 0.56; 95 percent confidence interval, 0.43 to 0.75; P<0.001 by the log-rank test). The probability of disease progression at two years was 0.19 with zidovudine, as compared with 0.34 with placebo (95 percent confidence interval for the difference, -0.21 to -0.08). Progression to CDC group IV disease was reduced by half in the zidovudine recipients (relative risk, 0.49; P = 0.049) and decline in CD4+ cell counts to below 350 per cubic millimeter was reduced by 40 percent (relative risk, 0.60; P<0.001). The inclusion of early HIV disease events (oral candidiasis, oral hairy leukoplakia, and herpes zoster) as end points confirmed the effects of zidovudine on the progression of clinical disease (relative risk, 0.55; 95 percent confidence interval, 0.37 to 0.84; P = 0.004). The median duration of treatment was 94 weeks. Severe hematologic or clinical side effects were rare. Conclusions: Treatment with zidovudine benefits HIV-infected persons with CD4+ cell counts above 400 per cubic millimeter. Despite the use of doses larger than those now generally prescribed, zidovudine was well tolerated for up to three years by most of our patients