Nitrogen and phosphorus limitation of oceanic microbial growth during spring in the Gulf of Aqaba

Bioassay experiments were performed to identify how growth of key groups within the microbial community was simultaneously limited by nutrient (nitrogen and phosphorus) availability during spring in the Gulf of Aqaba's oceanic waters. Measurements of chlorophyll a (chl a) concentration and fast repetition rate (FRR) fluorescence generally demonstrated that growth of obligate phototrophic phytoplankton was co-limited by N and P and growth of facultative aerobic anoxygenic photoheterotropic (AAP) bacteria was limited by N. Phytoplankton exhibited an increase in chl a biomass over 24 to 48 h upon relief of nutrient limitation. This response coincided with an increase in photosystem II (PSII) photochemical efficiency (F v /F m), but was preceded (within 24 h) by a decrease in effective absorption crosssection (σPSII) and electron turnover time (τ). A similar response for τ and bacterio-chl a was observed for the AAPs. Consistent with the up-regulation of PSII activity with FRR fluorescence were observations of newly synthesized PSII reaction centers via low temperature (77K) fluorescence spectroscopy for addition of N (and N + P). Flow cytometry revealed that the chl a and thus FRR fluorescence responses were partly driven by the picophytoplankton (æ10 μm) community, and in particular Synechococcus. Productivity of obligate heterotrophic bacteria exhibited the greatest increase in response to a natural (deep water) treatment, but only a small increase in response to N and P addition, demonstrating the importance of additional substrates (most likely dissolved organic carbon) in moderating the heterotrophs. These data support previous observations that the microbial community response (autotrophy relative to heterotrophy) is critically dependent upon the nature of transient nutrient enrichment. © Inter-Research 2009

CdS/Cu(In,Ga)S2 based solar cells with efficiencies reaching 12.9% prepared by a rapid thermal process

In this letter, we report externally confirmed total area efficiencies reaching up to 12.9% for CdS/Cu(In,Ga)S2 based solar cells. These are the highest externally confirmed efficiencies for such cells. The absorbers were prepared from sputtered metals subsequently sulfurized using rapid thermal processing in sulfur vapor. Structural, compositional, and electrical properties of one of these champion cells are presented. The correlation between the Ga distribution profile and solar cell properties is discussed

Small world yields the most effective information spreading

Spreading dynamics of information and diseases are usually analyzed by using a unified framework and analogous models. In this paper, we propose a model to emphasize the essential difference between information spreading and epidemic spreading, where the memory effects, the social reinforcement and the non-redundancy of contacts are taken into account. Under certain conditions, the information spreads faster and broader in regular networks than in random networks, which to some extent supports the recent experimental observation of spreading in online society [D. Centola, Science {\bf 329}, 1194 (2010)]. At the same time, simulation result indicates that the random networks tend to be favorable for effective spreading when the network size increases. This challenges the validity of the above-mentioned experiment for large-scale systems. More significantly, we show that the spreading effectiveness can be sharply enhanced by introducing a little randomness into the regular structure, namely the small-world networks yield the most effective information spreading. Our work provides insights to the understanding of the role of local clustering in information spreading.Comment: 6 pages, 7 figures, accepted by New J. Phy

Exploring Brain Derived Neurotrophic Factor and Cell Adhesion Molecules as Biomarkers for the Transdiagnostic Symptom Anhedonia in Alcohol Use Disorder and Comorbid Depression

Background: Alcohol Use Disorder (AUD) and depressive disorder often co-exist and have a shared heritability. This study aimed to investigate Brain-Derived Neurotrophic Factor (BDNF) and three Cell Adhesion Molecules (CAMs) as transdiagnostic biomarkers in AUD and depression co-morbidity. Methods: In a cross-sectional study, patients with AUD (n=22), AUD and depression (n=19), and healthy controls (n=20) were examined. Depression and anxiety severity were assessed using the Hamilton Depression Rating Scale and the Hamilton Anxiety Rating Scale. Anhedonia, alcohol use and dependence, craving, and social adaptation were assessed through self-report questionnaires. BDNF and CAM concentrations in peripheral serum were measured after overnight fasting using a Luminex assay. After controlling for age and gender, biomarker levels were compared across groups. The association between biomarker concentrations and symptom severity scales were explored using correlation and multiple regression analyses. Results: BDNF and Neuronal CAM were lower in patients with AUD with and without depression compared to healthy controls. No differences were observed for Vascular CAM-1 and Interstitial CAM-1. BDNF correlated negatively with anhedonia levels. BDNF, age and gender together explained 21% of variability in anhedonia levels. Conclusion: This pilot study suggests that peripheral levels of BDNF and NCAM might be reduced in AUD with and without comorbid mood disorder. Since low BDNF levels were associated with self- reported anhedonia across these conditions, BDNF and anhedonia might reflect transdiagnostic aspects involved in AUD and depression

Health economic evaluation of nation-wide screening programmes for atrial fibrillation in the Netherlands

AIMS: Screening for atrial fibrillation (AF) is recommended by the European Society of Cardiology guideline to prevent strokes. Cost-effectiveness analyses of different screening programs for AF are difficult to compare, because of varying settings and models used. We compared the impact and cost-effectiveness of various AF screening programs in the Netherlands.METHODS AND RESULTS: The base case economic analysis was conducted from the societal perspective. Health effects and costs were analysed using a Markov model. The main model inputs were derived from the ARISTOTLE, RE-LY and ROCKET AF trial combined with Dutch observational data. Univariate, probabilistic sensitivity and various scenario analyses were performed. The maximum number of newly detected AF patients in The Netherlands ranged from 4554 to 39 270, depending on the screening strategy used. Adequate treatment with anticoagulation would result in a maximum of more than 3000 strokes prevented using single time point AF screening. Compared with no screening, screening 100 000 persons provided a gain in QALYs ranging from 984 to 8727, and a mean cost difference ranging from -6650 000€ to 898 000€, depending on the screening strategy used. Probabilistic sensitivity analysis (PSA) demonstrated a 100% likelihood that screening all patients ≥ 75 years visiting the Geriatric outpatient clinic was cost-saving. Four out of six strategies were cost-saving in ≥ 74% of the PSA simulations. Out of these, opportunistic screening of all patients ≥ 65 years visiting the GPs office had the highest impact on strokes prevented.CONCLUSION: Most single-time point AF screening strategies are cost-saving and have an important impact on stroke prevention.</p

Health economic evaluation of nation-wide screening programmes for atrial fibrillation in the Netherlands

AIMS: Screening for atrial fibrillation (AF) is recommended by the European Society of Cardiology guideline to prevent strokes. Cost-effectiveness analyses of different screening programs for AF are difficult to compare, because of varying settings and models used. We compared the impact and cost-effectiveness of various AF screening programs in the Netherlands.METHODS AND RESULTS: The base case economic analysis was conducted from the societal perspective. Health effects and costs were analysed using a Markov model. The main model inputs were derived from the ARISTOTLE, RE-LY and ROCKET AF trial combined with Dutch observational data. Univariate, probabilistic sensitivity and various scenario analyses were performed. The maximum number of newly detected AF patients in The Netherlands ranged from 4554 to 39 270, depending on the screening strategy used. Adequate treatment with anticoagulation would result in a maximum of more than 3000 strokes prevented using single time point AF screening. Compared with no screening, screening 100 000 persons provided a gain in QALYs ranging from 984 to 8727, and a mean cost difference ranging from -6650 000€ to 898 000€, depending on the screening strategy used. Probabilistic sensitivity analysis (PSA) demonstrated a 100% likelihood that screening all patients ≥ 75 years visiting the Geriatric outpatient clinic was cost-saving. Four out of six strategies were cost-saving in ≥ 74% of the PSA simulations. Out of these, opportunistic screening of all patients ≥ 65 years visiting the GPs office had the highest impact on strokes prevented.CONCLUSION: Most single-time point AF screening strategies are cost-saving and have an important impact on stroke prevention.</p

Health economic evaluation of nation-wide screening programmes for atrial fibrillation in the Netherlands

AIMS: Screening for atrial fibrillation (AF) is recommended by the European Society of Cardiology guideline to prevent strokes. Cost-effectiveness analyses of different screening programs for AF are difficult to compare, because of varying settings and models used. We compared the impact and cost-effectiveness of various AF screening programs in the Netherlands.METHODS AND RESULTS: The base case economic analysis was conducted from the societal perspective. Health effects and costs were analysed using a Markov model. The main model inputs were derived from the ARISTOTLE, RE-LY and ROCKET AF trial combined with Dutch observational data. Univariate, probabilistic sensitivity and various scenario analyses were performed. The maximum number of newly detected AF patients in The Netherlands ranged from 4554 to 39 270, depending on the screening strategy used. Adequate treatment with anticoagulation would result in a maximum of more than 3000 strokes prevented using single time point AF screening. Compared with no screening, screening 100 000 persons provided a gain in QALYs ranging from 984 to 8727, and a mean cost difference ranging from -6650 000€ to 898 000€, depending on the screening strategy used. Probabilistic sensitivity analysis (PSA) demonstrated a 100% likelihood that screening all patients ≥ 75 years visiting the Geriatric outpatient clinic was cost-saving. Four out of six strategies were cost-saving in ≥ 74% of the PSA simulations. Out of these, opportunistic screening of all patients ≥ 65 years visiting the GPs office had the highest impact on strokes prevented.CONCLUSION: Most single-time point AF screening strategies are cost-saving and have an important impact on stroke prevention.</p

Health economic evaluation of nation-wide screening programmes for atrial fibrillation in the Netherlands

AIMS: Screening for atrial fibrillation (AF) is recommended by the European Society of Cardiology guideline to prevent strokes. Cost-effectiveness analyses of different screening programs for AF are difficult to compare, because of varying settings and models used. We compared the impact and cost-effectiveness of various AF screening programs in the Netherlands.METHODS AND RESULTS: The base case economic analysis was conducted from the societal perspective. Health effects and costs were analysed using a Markov model. The main model inputs were derived from the ARISTOTLE, RE-LY and ROCKET AF trial combined with Dutch observational data. Univariate, probabilistic sensitivity and various scenario analyses were performed. The maximum number of newly detected AF patients in The Netherlands ranged from 4554 to 39 270, depending on the screening strategy used. Adequate treatment with anticoagulation would result in a maximum of more than 3000 strokes prevented using single time point AF screening. Compared with no screening, screening 100 000 persons provided a gain in QALYs ranging from 984 to 8727, and a mean cost difference ranging from -6650 000€ to 898 000€, depending on the screening strategy used. Probabilistic sensitivity analysis (PSA) demonstrated a 100% likelihood that screening all patients ≥ 75 years visiting the Geriatric outpatient clinic was cost-saving. Four out of six strategies were cost-saving in ≥ 74% of the PSA simulations. Out of these, opportunistic screening of all patients ≥ 65 years visiting the GPs office had the highest impact on strokes prevented.CONCLUSION: Most single-time point AF screening strategies are cost-saving and have an important impact on stroke prevention.</p

Excessive extracellular ATP desensitizes P2Y2 and P2X4 ATP receptors provoking surfactant impairment ending in ventilation-induced lung injury

Stretching the alveolar epithelial type I (AT I) cells controls the intercellular signaling for the exocytosis of surfactant by the AT II cells through the extracellular release of adenosine triphosphate (ATP) (purinergic signaling). Extracellular ATP is cleared by extracellular ATPases, maintaining its homeostasis and enabling the lung to adapt the exocytosis of surfactant to the demand. Vigorous deformation of the AT I cells by high mechanical power ventilation causes a massive release of extracellular ATP beyond the clearance capacity of the extracellular ATPases. When extracellular ATP reaches levels >100 μM, the ATP receptors of the AT II cells become desensitized and surfactant impairment is initiated. The resulting alteration in viscoelastic properties and in alveolar opening and collapse time-constants leads to alveolar collapse and the redistribution of inspired air from the alveoli to the alveolar ducts, which become pathologically dilated. The collapsed alveoli connected to these dilated alveolar ducts are subject to a massive strain, exacerbating the ATP release. After reaching concentrations >300 μM extracellular ATP acts as a danger-associated molecular pattern, causing capillary leakage, alveolar space edema, and further deactivation of surfactant by serum proteins. Decreasing the tidal volume to 6 mL/kg or less at this stage cannot prevent further lung injury