Relevance of large litter bag burial for the study of leaf breakdown in the hyporheic zone

Particulate organic matter is the major source of energy for most low-order streams, but a large part of this litter is buried within bed sediment during floods and thus become poorly available for benthic food webs. The fate of this buried litter is little studied. In most cases, measures of breakdown rates consist of burying a known mass of litter within the stream sediment and following its breakdown over time. We tested this method using large litter bags (15 x 15 cm) and two field experiments. First, we used litter large bags filled with Alnus glutinosa leaves (buried at 20 cm depth with a shovel) in six stations within different land-use contexts and with different sediment grain sizes. Breakdown rates were surprisingly high (0.0011–0.0188 day-1) and neither correlate with most of the physico-chemical characteristics measured in the interstitial habitats nor with the land-use around the stream. In contrast, the rates were negatively correlated with a decrease in oxygen concentrations between surface and buried bags and positively correlated with both the percentage of coarse particles (20–40 mm) in the sediment and benthic macro-invertebrate richness. These results suggest that the vertical exchanges with surface water in the hyporheic zone play a crucial role in litter breakdown. Second, an experimental modification of local sediment (removing fine particles with a shovel to increase vertical exchanges) highlighted the influence of grain size on water and oxygen exchanges, but had no effect on hyporheic breakdown rates. Burying large litter bags within sediments may thus not be a relevant method, especially in clogged conditions, due to changes induced through the burial process in the vertical connectivity between surface and interstitial habitats that modify organic matter processing

The Amsterdam Studies of Acute Psychiatry - II (ASAP-II): a comparative study of psychiatric intensive care units in the Netherlands

Background The number of patients in whom mental illness progresses to stages in which acute, and often forced treatment is warranted, is on the increase across Europe. As a consequence, more patients are involuntarily admitted to Psychiatric Intensive Care Units (PICU). From several studies and reports it has become evident that important dissimilarities exist between PICU's. The current study seeks to describe organisational as well as clinical and patient related factors across ten PICU's in and outside the Amsterdam region, adjusted for or stratified by level of urbanization. Method/Design This paper describes the design of the Amsterdam Studies of Acute Psychiatry II (ASAP-II). This study is a prospective observational cohort study comparing PICU's in and outside the Amsterdam region on various patient characteristics, treatment aspects and recovery related variables. Dissimilarities were measured by means of collecting standardized forms which were filled out in the framework of care as usual, by means of questionnaires filled out by mental health care professionals and by means of extracting data from patient files for every consecutive patient admitted at participating PICU's during a specific time period. Urbanization levels for every PICU were calculated conform procedures as proposed by the Dutch Central Bureau for Statistics (CBS). Discussion The current study may provide a deeper understanding of the differences between psychiatric intensive care units that can be used to promote best practice and benchmarking procedures, and thus improve the standard of care

Scholarship on Gender and Sport in Sex Roles and Beyond

In this paper we critically review how research on girls or women and sport has developed over the last 35 years. We use a post-positivist lens to explore the content of the papers published in Sex Roles in the area of women, gender and sport and examine the shifts in how gender and sport have been conceptualized in these accounts. In order to initiate a broader dialogue about the scholarly analysis of gender and sport, we subsequently explore ideas inspired by feminist theorizing that have dominated/guided related research in other outlets over this time period but have received relatively little attention in papers published in Sex Roles. We conclude by briefly making suggestions for further research in this area

What can health inequalities researchers learn from an intersectionality perspective?:Understanding social dynamics with an inter-categorical approach

The concept of intersectionality was developed by social scientists seeking to analyse the multiple interacting influences of social location, identity and historical oppression. Despite broad take-up elsewhere, its application in public health remains underdeveloped. We consider how health inequalities research in the United Kingdom has predominantly taken class and later socioeconomic position as its key axis in a manner that tends to overlook other crucial dimensions. We especially focus on international research on ethnicity, gender and caste to argue that an intersectional perspective is relevant for health inequalities research because it compels researchers to move beyond (but not ignore) class and socioeconomic position in analysing the structural determinants of health. Drawing on these theoretical developments, we argue for an inter-categorical conceptualisation of social location that recognises differentiation without reifying social groupings – thus encouraging researchers to focus on social dynamics rather than social categories, recognising that experiences of advantage and disadvantage reflect the exercise of power across social institutions. Such an understanding may help address the historic tendency of health inequalities research to privilege methodological issues and consider different axes of inequality in isolation from one another, encouraging researchers to move beyond micro-level behaviours to consider the structural drivers of inequalities