Hydrolysis of organic phosphorus in soil water suspensions after addition of phosphatase enzymes

Additions of enzymes involved in organic phosphorus (P) hydrolysis can be used to characterize the hydrolyzability of molybdate-unreactive P (MUP) in soil water extracts. Our aim was to test the feasibility of enzyme additions to soil water suspensions with respect to (1) suitable enzyme preparations and (2) recovery of molybdate-reactive P (MRP). To this end, we compared the substrate specificity of seven commercially available enzyme preparations (acid and alkaline phosphomonoesterase, phytase, and nuclease preparations) and optimized the assay conditions in microplates. We then measured MRP release after the addition of the enzymes to soil water suspensions and filtrates of two Swiss grassland soils (midland and alpine). In some cases, commercial preparations of the same enzyme differed in their specificity, presumably due to contamination with other enzymes, and also in their efficiency in soil suspensions. Addition of EDTA to the buffer was required to decrease sorption of released P in soil suspensions. Enzymatic release of P was consistently equal or higher in soil suspensions than in soil filtrates. However, also more dissolved MUP was present in soil suspensions than in filtrates, since the buffer interacted with the solid phase. Of the total dissolved MUP in soil suspensions, 94 and 61% were hydrolyzable in midland and alpine soil, respectively. More specifically, 60 and 17% of MUP were in nucleic acids, 6 and 39% in simple monoesters, and 28 and 5% in inositol hexakisphosphate in midland and alpine soil, respectively. Thus, we show that the characterization of hydrolyzable organic P in soil suspensions with hydrolytic enzyme preparations may be useful to better understand the availability of soil organic P to enzymatic hydrolysis, but that it requires soil-specific adaptation for optimum P recover

Comparison of two telemetric intestinal temperature devices with rectal temperature during exercise.

The experienced discomfort of rectal probes and esophageal probes for the estimation of body core temperatures has triggered the development of GI-capsules that are easy acceptable for athletes and workers due to their non-invasive characteristics.
 We compare two new GI-capsule devices with rectal temperature during cycle ergometer exercise and rest. Eight participants followed a protocol of (i) 30 min exercise with a power output of 130 W, (ii) 5 min rest, (iii) 10 min self-paced maximum exercise, and (iv) 15 min rest. Core temperature was measured using two GI-capsule devices (e-Celsius and myTemp) and rectal temperature.
 The myTemp system gave temperatures indifferent different from rectal temperature during rest and exercise. However, the factory calibrated e-Celsius system, showed a systematic underestimation of rectal temperature of 0.2 °C that is corrected in the 2018 versions. Finally, both GI-capsules react faster to temperature changes in the body compared to the rectal temperature probe during the rest period following maximum exercise

Long-term addition of organic fertilizers has little effect on soil organic phosphorus as characterized by (31)P NMR spectroscopy and enzyme additions

Abstract not availableK.E. Annaheim, A.L. Doolette, R.J. Smernik, J. Mayer, A. Oberson, E. Frossard, E.K. Büneman

Effect of post-harvest handling and extraction on the content on echinacoside and cynarin in the root tissues of Echinacea angustifolia DC

Echinacea angustifolia DC is among the top-selling medicinal plants, whose pharmacological activity is due to several active principles, including caffeic acid derivatives (CAD). Plants grown under controlled conditions exhibit a large variability in composition, which may result from inadequate processing prior to HPLC analysis. Moreover, commercial preparations of E. angustifolia are normally obtained from dried roots and limited information is available on the extraction of fresh material, which may be required in research work. The paper shows how the post-harvest handling (i.e. storage temperature, drying conditions and extraction protocol) influenced the content of two main components, echinacoside and cynarin, in E. angustifolia roots. The two marker compounds were identified by means of LC-MS and quantified by HPLC with UV detection. A pooled sample of roots was prepared with plants from a controlled greenhouse hydroponic cultivation and six homogeneous aliquots were subjected to the following treatments: storage at -80°C (FR-80) or -20°C (FR-20), freeze-drying (FD), air- drying at room temperature (AD25), oven-drying at 50°C (AD50) or 75°C (AD75). Subsequently the samples were extracted according to a protocol reported in the literature. With the air- or oven-drying treatments, the concentrations of the marker compounds exhibited opposite dependence on temperature. Moreover, both echinacoside and cynarin were absent or scarce in FR-80, FR-20 and FD root samples. Some modifications of the original extraction method were therefore tested, aimed at improving the extraction efficiency. The final protocol that was developed consisted in the addition of acidified methanol 70% to the sample prior to grinding, to reduce the risk of air and enzymatic oxidation. No loss of metabolites, as determined through an internal standard (gallic acid), was observed with this method. Compared to the original extraction protocol, the modified one improved the extraction efficiency in AD50 roots and, above all, allowed the recovery of both echinacoside and cynarin in FR-80, FR-20 and FS samples. Despite the substantial improvement, in the latter samples the contents of the two marker compounds remained significantly lower than those found in oven-dried roots. These findings suggest that metabolite degradation may occur in roots which do not undergo dehydration, and the best post-handling process is oven-drying at 50°C or higher temperature

How to screen for problematic cannabis use in population surveys. An Evaluation of the Cannabis Use Disorders Identification Test (CUDIT) in a Swiss sample of adolescents and young adults

BACKGROUND/AIMS: Cannabis use is a growing challenge for public health, calling for adequate instruments to identify problematic consumption patterns. The Cannabis Use Disorders Identification Test (CUDIT) is a 10-item questionnaire used for screening cannabis abuse and dependency. The present study evaluated that screening instrument. METHODS: In a representative population sample of 5,025 Swiss adolescents and young adults, 593 current cannabis users replied to the CUDIT. Internal consistency was examined by means of Cronbach's alpha and confirmatory factor analysis. In addition, the CUDIT was compared to accepted concepts of problematic cannabis use (e.g. using cannabis and driving). ROC analyses were used to test the CUDIT's discriminative ability and to determine an appropriate cut-off. RESULTS: Two items ('injuries' and 'hours being stoned') had loadings below 0.5 on the unidimensional construct and correlated lower than 0.4 with the total CUDIT score. All concepts of problematic cannabis use were related to CUDIT scores. An ideal cut-off between six and eight points was found. CONCLUSIONS: Although the CUDIT seems to be a promising instrument to identify problematic cannabis use, there is a need to revise some of its items

A review on ergonomics of headgear: Thermal effects

The thermal effects related to wearing headgear are complex and different studies have investigated single parts of this topic. This review aims at summarizing the different findings to give a complete overview on this topic as well as to suggest new perspectives. Headgear increases head insulation and therefore is mainly problematic under warm conditions, which is the focus of this review. Helmets do not affect physiological parameters other than the local skin temperature and sweat rate. However, the head is among the most sensitive body parts related to thermal comfort, thereby directly affecting the willingness to wear headgear. Several methods have been used to study thermal aspects of headgear, which could be categorized as (i) numerical, (ii) biophysical, (iii) combined numerical and biophysical, and (iv) user trials. The application of these methods established that heat transfer mainly takes place through radiation and convection. Headgear parameters relevant to these heat transfer pathways, are reviewed and suggestions are provided for improving existing headgear concepts and developing new concepts, ultimately leading to more accepted headgear. Relevance to industry: This review provides a sound basis for improving existing headgear concepts. Firstly, a concise overview of headgear research related to thermal effects is given, leading to empirically based improvement suggestions and identification of research fields with a high potential. Finally, relevant research methods are described facilitating evaluation in R&D processes. (C) 2014 The Authors. Published by Elsevier Ltd