title: Diverse and highly active diazotrophic assemblages inhabit ephemerally wetted soils of the Antarctic Dry Valleys

authors: Niederberger, Thomas D.

subjects: diazotrophs

abstract: Eolian transport of biomass from ephemerally wetted soils, associated with summer glacial meltwater runoffs and lake edges, to low-productivity areas of the Antarctic Dry Valleys (DV) has been postulated to be an important source of organic matter (fixed nitrogen and fixed carbon) to the entire DV ecosystem. However, descriptions and identification of the microbial members responsible for N₂ fixation within these wetted sites are limited. In this study, N₂ fixers from wetted soils were identified by direct nifH gene sequencing and their in situ N₂ fixation activities documented via acetylene reduction and RNA-based quantitative PCR assays. Shannon-index nifH diversity levels ranged between 1.8 and 2.6 and included the expected cyanobacterial signatures and a large number of phylotypes related to the gamma-, beta-, alpha-, and delta-proteobacteria. N₂ fixation rates ranged between approximately 0.5 and 6 nmol N cm⁻³ h⁻¹ with measurements indicating that approximately 50% of this activity was linked with sulfate reduction at some sites. Comparisons with proximal dry soils also suggested that these communities are not ubiquitously distributed, and conditions unrelated to moisture content may define the composition, diversity, or habitat suitability of the microbial communities within wetted soils of the DVs.

text: Diverse and highly active diazotrophic assemblages inhabit ephemerally wetted soils of the Antarctic Dry Valleys Eolian transport of biomass from ephemerally wetted soils, associated with summer glacial meltwater runoffs and lake edges, to low-productivity areas of the Antarctic Dry Valleys (DV) has been postulated to be an important source of organic matter (fixed nitrogen and fixed carbon) to the entire DV ecosystem. However, descriptions and identification of the microbial members responsible for N₂ fixation within these wetted sites are limited. In this study, N₂ fixers from wetted soils were identified by direct nifH gene sequencing and their in situ N₂ fixation activities documented via acetylene reduction and RNA-based quantitative PCR assays. Shannon-index nifH diversity levels ranged between 1.8 and 2.6 and included the expected cyanobacterial signatures and a large number of phylotypes related to the gamma-, beta-, alpha-, and delta-proteobacteria. N₂ fixation rates ranged between approximately 0.5 and 6 nmol N cm⁻³ h⁻¹ with measurements indicating that approximately 50% of this activity was linked with sulfate reduction at some sites. Comparisons with proximal dry soils also suggested that these communities are not ubiquitously distributed, and conditions unrelated to moisture content may define the composition, diversity, or habitat suitability of the microbial communities within wetted soils of the DVs.

year: 2012

title: Exploring new frontiers to generate an integrated definition of workaholism

authors: McMillan, Lynley H.W.

subjects: workaholism

abstract: In general, contemporary data indicate that workaholism represents a value system about the importance of working and achieving that certainly does not meet the scientific criteria for addiction, as it is associated with a similar quality of health and relationships to that of the rest of the adult population, and generally does not worsen over time (McMilIan and O'Driscoll, 2004). Interestingly, while the majority of workaholics appear to derive high enjoyment from their work and their leisure, it is their reluctance to utilize psychological `off-buttons' that potentially makes them a challenging group for management professionals (Machlowitz, 1980).

text: Exploring new frontiers to generate an integrated definition of workaholism In general, contemporary data indicate that workaholism represents a value system about the importance of working and achieving that certainly does not meet the scientific criteria for addiction, as it is associated with a similar quality of health and relationships to that of the rest of the adult population, and generally does not worsen over time (McMilIan and O'Driscoll, 2004). Interestingly, while the majority of workaholics appear to derive high enjoyment from their work and their leisure, it is their reluctance to utilize psychological `off-buttons' that potentially makes them a challenging group for management professionals (Machlowitz, 1980).

year: 2006

title: Handbook of indigenous peoples' rights [Book review]

authors: Te Aho, Linda

abstract: This article reviews the book “Handbook of indigenous peoples' rights”, edited by Corinne Lennox and Damien

text: Handbook of indigenous peoples' rights [Book review] This article reviews the book “Handbook of indigenous peoples' rights”, edited by Corinne Lennox and Damien

year: 2016