657 research outputs found

    Decadal water balance of a temperate Scots pine forest (Pinus sylvestris L.) based on measurements and modelling

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    We examined the water balance components of an 80-year-old Scots pine (Pinus sylvestris L.) forest stand in the Campine region of Belgium over a ten year period using five very different approaches; our methods ranged from data intensive measurements to process model simulations. Specifically, we used the conservative ion method (CI), the Eddy Covariance technique (EC), an empirical model (WATBAL), and two process models that vary greatly in their temporal and spatial scaling, the ORCHIDEE global land-surface model and SECRETS a stand- to ecosystem-scale biogeochemical process model. Herein we used the EC technique as a standard for the evapotranspiration (ET) estimates. Using and evaluating process based models with data is extremely useful as models are the primary method for integration of small-scale, process level phenomena into comprehensive description of forest stand or ecosystem function. Results demonstrated that the two process models corresponded well to the seasonal patterns and yearly totals of ET from the EC approach. However, both WATBAL and CI approaches overestimated ET when compared to the EC estimates. We found significant relationships between several meteorological variables (i.e., vapour pressure deficit [VPD], mean air temperature [Tair], and global radiation [Rg]) and ET on monthly basis for all approaches. In contrast, few relationships were significant on annual basis. Independent of the method examined, ET exhibited low inter-annual variability. Consequently, drainage fluxes were highly correlated with annual precipitation for all approaches examined, except CI

    Effectiveness of some recent antimicrobial packaging concepts

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    A new type of active packaging is the combination of food-packaging materials with antimicrobial substances to control microbial surface contamination of foods. For both migrating and non-migrating antimicrobial materials, intensive contact between the food product and packaging material is required and therefore potential food applications include especially vacuum or skin-packaged products, e.g. vacuum-packaged meat, fish, poultry or cheese. Several antimicrobial compounds have been combined with different types of carriers (plastic and rubber articles, paper-based materials, textile fibrils and food-packaging materials). Until now, however, few antimicrobial concepts have found applications as a food-packaging material. Antimicrobial packaging materials cannot legally be used in the EU at the moment. The potential use would require amendments of several different legal texts involving areas such as food additives, food packaging, hygiene, etc. The main objective of this paper is to provide a state of the art about the different types of antimicrobial concepts, their experimental development and commercialization, and to present a case study summarizing the results of investigations on the feasibility of a low-density polyethylene (LDPE)-film containing triclosan to inhibit microbial growth on food surfaces and consequently prolong shelf-life or improve microbial food safety. In contrast with the strong antimicrobial effect in in-vitro simulated vacuum-packaged conditions against the psychrotrophic food pathogen L. monocytogenes, the 1000 mg kg(-1) containing triclosan film did not effectively reduce spoilage bacteria and growth of L. monocytogenes on refrigerated vacuum-packaged chicken breasts stored at 7 degrees C

    Study on antimicrobial activity of aq food packaging material containing potassium sorbate

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    The feasibility of EVA/LLDPE films containing 1, 2 and 5% (w/w) K-sorbate to inhibit microbial growth and as a consequence prolong shelf-life of foods was investigated. Based on weight loss experiments it was shown that K-sorbate is very suitable for incorporation in LLDPE because of its heat stability during extrusion. After 3 weeks, resp. 6.4, 2.8 and 5.7% of the incorporated sorbic acid was released into distilled water from films containing resp. 1, 2 and 5% (w/w) K-sorbate. The very limited migration of K-sorbate may be explained by the incompatibility of the polar salt with the apolar LLDPE. This limited migration could explain the very small inhibitory effect of the K-sorbate films on the growth of Candida spp., Pichia spp., Trichosporon spp. and Penicillium spp. During storage at 7 °C of cheese packaged in a 5% (w/w) K-sorbate film, no significant differences could be observed for yeast and mould growth on the cheese cubes compared to a reference film. The concentration of sorbic acid in the cheese did not exceed 14 ppm. This is much lower than the 1000 ppm K-sorbate needed to inhibit microbial growth. The results of this study confirm that the K-sorbate incorporated LLDPE film is not able to inhibit microbial growth in vitro on inoculated media and in vivo on cheese due to the insufficient release of K-sorbate from the film

    Parental awareness of sexual experience in adolescent boys with autism spectrum disorder

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    Parent report and adolescent self-report data on lifetime sexual experience in adolescents with ASD were compared in 43 parent-adolescent dyads. Parents tended to underestimate the lifetime sexual experience of their sons, particularly solo sexual experiences such as masturbation and experience with orgasm. Parental underestimation and unawareness of adolescents’ sexual experience may influence communication and education about sex and sexuality in families. These findings have implications for the interpretation of earlier research, based on parent and caregiver reports, on sexuality in adolescents with ASD

    Influence of ionic and non-ionic radiographic contrast media on leukocyte adhesion molecules.

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    BACKGROUND: Many papers have focused on the importance of granulocytes in the process of reperfusion and ischemia. Most of the clinical studies measured several parameters of this process during and after coronary angiography, without taking into account the effect of the radiographic contrast media (RCM) used during this procedure. MATERIALS AND METHODS: We performed a randomized patient study (n = 37) to evaluate the effect of ionic and non-ionic RCM on granulocyte adhesion during coronary angiography. We also evaluated the influence of the ionicity and osmolarity of the different substances on granulocyte adhesion molecules in in vitro experiments. RESULTS: The osmolarity of patient serum samples increased from 302 +/- 1 to 309 +/- 1 mOsm/kg (p < 0.05) after infusion of RCM. The CD11b expression in the samples of the non-ionic RCM treated group increased from 221 +/- 21 MFI to 377 +/- 30 MFI (p < 0.05) measured as the absolute mean fluorescence intensity (MFI), yet did not alter significantly in the ionic RCM group. In contrast, the in vitro experiments showed a reduction of the CD11b expression from 360 +/- 70 MFI to 149 +/- 30 MFI (p < 0.05) in the ionic RCM group. CONCLUSIONS: The upregulation of adhesion molecules was significantly reduced in vivo with ionic RCM, while ionic substances caused opposite effects in vitro. This effect should be taken into account when performing leukocyte functional analysis of samples taken during angiography

    Practical application and statistical analysis of titrimetric monitoring of water and sludge samples

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    Titrimetry offers the possibility of simultaneous measurement at low cost of several (buffering) components. A first step in the study towards practical application of the titrimetric technique was the titrimetric analysis by up- or down-titration of standard solutions, standard mixtures, solids digester samples and water samples coming from autotrophic nitrogen-removal reactors. The resulting raw data were further processed with an Excel-based program. This program first converts the raw data into a buffer curve upon which a linear buffer capacity model is fitted to the experimental data by estimating the (buffer) concentrations and corresponding pKa values. As such the type of component and the concentration can be determined. As a second step the resulting calculated concentrations were analysed statistically to assess the accuracy and precision of the titrimetric technique. For this purpose, the data were paired, i.e. the difference between the concentration obtained with titrimetry and the concentration obtained with another technique such as colorimetry or gas chromatography was calculated. First the normality of the paired data was assessed. Then, a paired t-test (normal data) or a paired Wilcoxon test (normal data) was used to statistically compare the results obtained with the titrimetric technique to either the stock solution concentration or measurements with another method (colorimetry or gas chromatography). The statistical tests showed that, depending on the titrant concentration, concentrations from 50 mg/. to 3 000 mg/. could adequately be measured with the titrimetric technique

    Systemic Inflammation and Reperfusion Injury in Patients With Acute Myocardial Infarction

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    Despite early recanalization of an occluded infarct artery, tissue reperfusion remains impaired in more than one-third of the acute myocardial infarction (AMI) patients owing to a process of reperfusion injury. The role of systemic inflammation in triggering this phenomenon is unknown. Proinflammatory factors (hs-CRP, TNF-α) and anti-inflammatory mediators (IL-1 receptor antagonist, IL-10) were measured in 65 patients during the acute phase of a myocardial infarction as well as in 11 healthy control subjects. Myocardial reperfusion injury was defined as the presence of persistent ST-segment elevation despite successful coronary intervention (≥ 50% of the initial value) and was observed in 28 patients. Systemic proinflammatory mediators (particularly hs-CRP and leukocytes) were higher in AMI patients compared to control subjects. Within the group of AMI patients, only serum TNF-α differed significantly between patients with versus without reperfusion injury: a median value of 25 versus 13 pg/mL was observed, respectively. Logistic regression analysis identified a high level of TNF-α as the most important independent determinant of reperfusion injury (P = .001), beyond total ischemic time (P = .01) and extent of jeopardized myocardium (P = .08). There was no correlation between the TNF-α level and the total ischemic time (P = .8) or the extent of jeopardized myocardium (P = .6). Systemic inflammation, in particular high levels of TNF-α, is strongly associated with the occurrence of reperfusion injury after successful recanalization. Our findings suggest that TNF-α is involved in the triggering and/or amplification of local inflammatory responses related to ischemia-reperfusion injury

    Towards integrated youth care : a systematic review of facilitators and barriers for professionals

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    To overcome fragmentation in support for children and their families with multiple and enduring problems across life domains, professionals increasingly try to organize integrated care. However, it is unclear what facilitators and barriers professionals experience when providing this integrated care. Our systematic review, including 55 studies from a broad variety of settings in Youth Care, showed that integrated care on a professional level is a multi-component entity consisting of several facilitators and barriers. Findings were clustered in seven general themes: ‘Child’s environment’, ‘Preconditions’, ‘Care process’, ‘Expertise’, ‘Interprofessional collaboration’, ‘Information exchange’, and ‘Professional identity’. The identified facilitators and barriers were generally consistent across studies, indicating broad applicability across settings and professional disciplines. This review clearly shows that when Youth Care professionals address a broad spectrum of problems, a variety of facilitators and barriers should be considered. Registration PROSPERO, registration number CRD42018084527
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