Understanding the nature of atmospheric acid processing of mineral dusts in supplying bioavailable phosphorus to the oceans

Acidification of airborne dust particles can dramatically increase the amount of bioavailable phosphorus (P) deposited on the surface ocean. Experiments were conducted to simulate atmospheric processes and determine the dissolution behaviour of phosphorus compounds in dust and dust precursors oils. Acid dissolution occurs rapidly (seconds to minutes) and is controlled by the amount of H + ions present. For H + 10-4 mol per gram of dust, the amount of phosphorus (and Ca) released follows a power law dependent on the amount of H + consumed until all inorganic phosphorus minerals are exhausted and the final pH remains acidic. Once dissolved, phosphorus will stay in solution due to slow precipitation kinetics. Dissolution of apatite-P, the major mineral phase in dust (79-96%), occurs whether CaCO 3 is present or not, though the increase in dissolved phosphorus is greater if CaCO 3 is absent or if the particles are externally mixed. The system was modelled adequately as a simple mixture of apatite-P and calcite. Phosphorus dissolves readily by acid processes in the atmosphere in contrast to iron, which dissolves slower and is subject to re-precipitation at cloud water pH. We show that acidification can increase bioavailable phosphorus deposition over large areas of the globe, and may explain much of the previously observed patterns of variability in leachable phosphorus in oceanic areas where primary productivity is limited by this nutrient (e.g. Mediterranean)

Awareness of dementia risk reduction among current and future healthcare professionals: A survey study

Background: The total number of people affected by dementia worldwide is increasing rapidly. Recent studies provided evidence for the contribution of modifiable risk and protective factors to dementia risk. Although healthcare professionals could play an essential role in informing the general public about the relationship between lifestyle and dementia, it is unclear what they know about this relationship. Therefore, this study assesses the awareness of dementia risk reduction among current and future healthcare professionals.Design and methods: An online survey was carried out among 182 healthcare students from Maastricht University and 20 general practitioners (GPs) and practice nurses in Limburg, The Netherlands. The survey assessed the knowledge about risk and protective factors of dementia and identified needs, wishes and barriers concerning dementia risk reduction strategies.Results: The majority of current (75.0%) and future (81.9%) healthcare professionals indicated that dementia risk reduction is possible. Among students, awareness of cardiovascular risk factors of dementia (e.g., coronary heart disease (44.5%), hypertension (53.8%)) was low. Most participants (>70.0%) would like to receive more information about dementia risk reduction.Conclusions: The majority of current and future healthcare professionals were aware of the relationship between lifestyle and dementia risk. However, there are still substantial gaps in knowledge regarding individual dementia risk factors. Given the essential role of healthcare professionals in providing lifestyle advice, there is a need to increase awareness by providing educational programs focused on dementia risk reduction

The effect of atmospheric acid processing on the global deposition of bioavailable phosphorus from dust

The role of dust as a source of bioavailable phosphorus (Bio-P) is quantified using a new parameterization for apatite dissolution in combination with global soil data maps and a global aerosol transport model. Mineral dust provides 31.2 Gg-P yr-1 of Bio-P to the oceans, with 14.3 Gg-P yr-1 from labile P present in the dust, and an aditional 16.9 Gg-P yr from acid dissolution of apatite in the atmosphere, representing an increase of 120%. The North Atlantic, north west Pacific, and Mediterranean Sea are identified as important sites of Bio-P deposition from mineral dust. The acid dissolution process increases the fraction of total-P that is bioavailable from ~10% globally from the labile pool to 23% in the Atlantic Ocean, 45% in the Pacific Ocean, and 21% in the Indian Ocean, with an ocean global mean value of 22%. Strong seasonal variations, especially in the North Pacific, northwest Atlantic, and Indian Ocean, are driven by large-scale meteorology and pollution sources from industrial and biomass-burning regions. Globally constant values of total-P content and bioavailable fraction used previously do not capture the simulated variability. We find particular sensitivity to the representation of particle-to-particle variability of apatite, which supplies Bio-P through acid-dissolution, and calcium carbonate, which helps to buffer the dissolution process. A modest 10% external mixing results in an increase of Bio-P deposition by 18%. The total Bio-P calculated here (31.2 Gg-P yr-1) represents a minimum compared to previous estimates due to the relatively low total-P in the global soil map used

Coastal upwelling in the Rias Bajas, NW Spain: Contrasting the benthic regimes of the Rias de Arosa and de Muros

Nutrient-rich North Atlantic water upwells off the NW coast of Spain and intermittently intrudes into the rias, coastal embayments, by displacement during periods of offshore winds. High primary production associated with the upwelling supports an intensive raft culture of the edible mussel, Mytilus edulis. This culture is most intensive (ca. 2000 rafts) in the Ria de Arosa, and results in one of the highest protein yields per unit area on earth...

Coastal upwelling in the Rías Bajas, NW Spain: Contrasting the benthic regimes of Rías de Arosa and de Muros

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Carpal tunnel syndrome and the use of computer mouse and keyboard: A systematic review

<p>Abstract</p> <p>Background</p> <p>This review examines evidence for an association between computer work and carpal tunnel syndrome (CTS).</p> <p>Methods</p> <p>A systematic review of studies of computer work and CTS was performed. Supplementary, longitudinal studies of low force, repetitive work and CTS, and studies of possible pathophysiological mechanisms were evaluated.</p> <p>Results</p> <p>Eight epidemiological studies of the association between computer work and CTS were identified. All eight studies had one or more limitation including imprecise exposure and outcome assessment, low statistical power or potentially serious biases. In three of the studies an exposure-response association was observed but because of possible misclassification no firm conclusions could be drawn. Three of the studies found risks below 1. Also longitudinal studies of repetitive low-force non-computer work (n = 3) were reviewed but these studies did not add evidence to an association. Measurements of carpal tunnel pressure (CTP) under conditions typically observed among computer users showed pressure values below levels considered harmful. However, during actual mouse use one study showed an increase of CTP to potentially harmful levels. The long term effects of prolonged or repeatedly increased pressures at these levels are not known, however.</p> <p>Conclusion</p> <p>There is insufficient epidemiological evidence that computer work causes CTS.</p

Laugh Like You Mean It:Authenticity Modulates Acoustic, Physiological and Perceptual Properties of Laughter

Several authors have recently presented evidence for perceptual and neural distinctions between genuine and acted expressions of emotion. Here, we describe how differences in authenticity affect the acoustic and perceptual properties of laughter. In an acoustic analysis, we contrasted spontaneous, authentic laughter with volitional, fake laughter, finding that spontaneous laughter was higher in pitch, longer in duration, and had different spectral characteristics from volitional laughter that was produced under full voluntary control. In a behavioral experiment, listeners perceived spontaneous and volitional laughter as distinct in arousal, valence, and authenticity. Multiple regression analyses further revealed that acoustic measures could significantly predict these affective and authenticity judgements, with the notable exception of authenticity ratings for spontaneous laughter. The combination of acoustic predictors differed according to the laughter type, where volitional laughter ratings were uniquely predicted by harmonics-to-noise ratio (HNR). To better understand the role of HNR in terms of the physiological effects on vocal tract configuration as a function of authenticity during laughter production, we ran an additional experiment in which phonetically trained listeners rated each laugh for breathiness, nasality, and mouth opening. Volitional laughter was found to be significantly more nasal than spontaneous laughter, and the item-wise physiological ratings also significantly predicted affective judgements obtained in the first experiment. Our findings suggest that as an alternative to traditional acoustic measures, ratings of phonatory and articulatory features can be useful descriptors of the acoustic qualities of nonverbal emotional vocalizations, and of their perceptual implications