Understanding how plant functional traits shape nutrient limitation and cycling on land is a major challenge in ecology. This is especially true for lowland forest ecosystems of the tropics which can be taxonomically and functionally diverse and rich in bioavailable nitrogen (N). In many tropical regions, however, diverse forests occur side-by-side with monodominant forest (one species >60% of ...

INTRODUCTION Various forms of vitamin D and factors involved in their metabolism can play a role in the etiopathogenesis of metabolic disorders. This paper aims to define the relationship between concentration of the hydroxylated form of vitamin D (25(OH)D), the fraction of free and bioavailable vitamin D, and of vitamin D binding protein (VDBP) levels on the one hand and the prevalence of meta...

OBJECTIVE Previous reports of an association between low testosterone levels and diabetes risk were often confounded by covariation of sex hormone-binding globulin (SHBG) and testosterone measurements. Measurements of bioavailable and free testosterone, more reliable indexes of biologically active testosterone, were examined for their associations with markers of insulin resistance and body fat...

The potential for human exposure to arsenic (As), a group A carcinogen, has increased tremendously because of the encroachment of suburban areas into former agricultural lands, where arsenical pesticides were used extensively prior to the 1990s. Many baseline risk assessments of As-enriched sites assume that all (100%) As present in the soil is bioavailable because of the high expenses and logi...

Biogeosciences Discussions This discussion paper is/has been under review for the journal Biogeosciences (BG). Please refer to the corresponding final paper in BG if available. Abstract Dissolved organic carbon (DOC) and total dissolved amino acids (TDAA) were measured in high (Chukchi Sea) and low (Beaufort Sea) productivity regions of the Western Arctic Ocean to investigate the composition an...

[1] At least 15% of the 2 Pg y 1 of dissolved organic carbon (DOC) that accumulates in the surface layer of the open ocean has been exported from the ocean margins. The C: N: P stoichiometry of the production and microbial degradation of dissolved organic matter (DOM) in the coastal ocean conditions the quality of the exported substrates. In this work, DOC, dissolved organic nitrogen (DON) and ...

Postmenopausal women with increased estrogens and lowered sex hormone-binding globulin (SHBG) concentrations are at increased risk of breast cancer. In the Multiethnic Cohort Study, the highest incidence rates of postmenopausal breast cancer were observed among Native Hawaiians followed by Japanese Americans, Whites, African Americans, and Latinas. Ethnic differences in endogenous sex hormone p...

OBJECTIVE Low levels of androgens in men may play a role in the development of diabetes; however, few studies have examined the association between androgen concentration and diabetes in men in the general population. The objective of this study is to test the hypothesis that low normal levels of total, free, and bioavailable testosterone are associated with prevalent diabetes in men. RESEARC...