474 research outputs found

    Wireless Sensor Network Deployment for Monitoring Soil Moisture Dynamics at the Field Scale

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    AbstractWe describe the deployment of a Wireless Sensor Network (WSN), composed of 135 soil moisture and 27 temperature sensors, in an apple tree orchard of about 5000 m2, located in the municipality of Cles, a small town in the Alpine region, northeastern Italy. The orchard is divided into three parcels each one subjected to a different irrigation schedule. The objective of the present work is to monitor soil moisture dynamics in the top soil to a detail, in both space and time, suitable to analyze the interplay between soil moisture dynamics and plant physiology. The deployment consists of 27 locations (verticals) connected by a multi hop WSN, each one equipped with 5 soil moisture sensors deployed at the depths of 10, 20, 30, 50 and 80 cm, and a temperature sensor at the depth of 20 cm. The proposed monitoring system is based on totally independent sensor nodes, which allow both real time and historic data management and are connected through an input/output interface to a WSN platform. Meteorological data are monitored by a weather station located at a distance of approximately 100 m from the experimental site.Great care has been posed to calibration of the capacitance sensors, both in the laboratory, with soil samples, and on site, after deployment, in order to minimize the noise caused by small oscillations in the input voltage and uncertainty in the calibration curves. In this work we report the results of a preliminary analysis on the data collected during the growing season 2009. We observed that the WSN greatly facilitates the collection of detailed measurements of soil moisture, thereby increasing the amount of information useful for exploring hydrological processes, but they should be used with care since the accuracy of collected data depends critically on the capability of the system to maintain constant the input voltage and on the reliability of calibration curves. Finally, we studied the spatial and temporal distribution of soil moisture in all the irrigated parcels, and explored how different irrigation schedules influence orchard's production

    Molecular mechanistic origin of the toughness of natural adhesives, fibres and composites

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    Natural materials are renowned for their strength and toughness(1-5). Spider dragline silk has a breakage energy per unit weight two orders of magnitude greater than high tensile steel(1,6), and is representative of many other strong natural fibres(3,7,8). The abalone shell, a composite of calcium carbonate plates sandwiched between organic material, is 3,000 times more fracture resistant than a single crystal of the pure mineral(4,5). The organic component, comprising just a few per cent of the composite by weight(9), is thought to hold the key to nacre's fracture toughness(10,11). Ceramics laminated with organic material are more fracture resistant than non-laminated ceramics(11,12), but synthetic materials made of interlocking ceramic tablets bound by a few weight per cent of ordinary adhesives do not have a toughness comparable to nacre(13). We believe that the key to nacre's fracture resistance resides in the polymer adhesive, and here we reveal the properties of this adhesive by using the atomic force microscope(14) to stretch the organic molecules exposed on the surface of freshly cleaved nacre. The adhesive fibres elongate in a stepwise manner as folded domains or loops are pulled open. The elongation events occur for forces of a few hundred piconewtons, which are smaller than the forces of over a nanonewton required to break the polymer backbone in the threads. We suggest that this 'modular' elongation mechanism might prove to be quite general for conveying toughness to natural fibres and adhesives, and we predict that it might be found also in dragline silk

    Metabolic profiles of whole, parotid and submandibular/sublingual saliva

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    The detection of salivary molecules associated with pathological and physiological alterations has encouraged the search of novel and non-invasive diagnostic biomarkers for oral health evaluation. While genomic, transcriptomic, and proteomic profiles of human saliva have been reported, its metabolic composition is a topic of research: metabolites in submandibular/sublingual saliva have never been analyzed systematically. In this study, samples of whole, parotid, and submandibular/ sublingual saliva from 20 healthy donors, without dental or periodontal diseases, were examined by nuclear magnetic resonance. We identified metabolites which are differently distributed within the three saliva subtypes (54 in whole, 49 in parotid, and 36 in submandibular/sublingual saliva). Principal component analysis revealed a distinct cluster for whole saliva and a partial overlap for parotid and submandibular/sublingual metabolites. We found exclusive metabolites for each subtype: 2-hydroxy-3-methylvalerate, 3-methyl-glutarate, 3-phenylpropionate, 4-hydroxyphenylacetate, 4-hydroxyphenyllactate, galactose, and isocaproate in whole saliva; caprylate and glycolate in submandibular/sublingual saliva; arginine in parotid saliva. Salivary metabolites were classified into standard and non-proteinogenic amino acids and amines; simple carbohydrates; organic acids; bacterial-derived metabolites. The identification of a salivary gland-specific metabolic composition in healthy people provides the basis to invigorate the search for salivary biomarkers associated with oral and systemic diseases

    Solar cycle variation of νmax in helioseismic data and its implications for asteroseismology

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    The frequency, νmax, at which the envelope of pulsation power peaks for solar-like oscillators is an important quantity in asteroseismology. We measure νmax for the Sun using 25 yr of Sun-as-a-star Doppler velocity observations with the Birmingham Solar-Oscillations Network (BiSON), by fitting a simple model to binned power spectra of the data. We also apply the fit to Sun-as-a-star Doppler velocity data from Global Oscillation Network Group and Global Oscillations at Low Frequency, and photometry data from VIRGO/SPM on the ESA/NASA SOHO spacecraft. We discover a weak but nevertheless significant positive correlation of the solar νmax with solar activity. The uncovered shift between low and high activity, of ≃25 μHz\simeq 25\, \rm \mu Hz, translates to an uncertainty of 0.8 per cent in radius and 2.4 per cent in mass, based on direct use of asteroseismic scaling relations calibrated to the Sun. The mean νmax in the different data sets is also clearly offset in frequency. Our results flag the need for caution when using νmax in asteroseismology

    Measurement of event shapes in deep inelastic scattering at HERA

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    Inclusive event-shape variables have been measured in the current region of the Breit frame for neutral current deep inelastic ep scattering using an integrated luminosity of 45.0 pb^-1 collected with the ZEUS detector at HERA. The variables studied included thrust, jet broadening and invariant jet mass. The kinematic range covered was 10 < Q^2 < 20,480 GeV^2 and 6.10^-4 < x < 0.6, where Q^2 is the virtuality of the exchanged boson and x is the Bjorken variable. The Q dependence of the shape variables has been used in conjunction with NLO perturbative calculations and the Dokshitzer-Webber non-perturbative corrections (`power corrections') to investigate the validity of this approach.Comment: 7+25 pages, 6 figure

    Coffee bean extracts rich and poor in kahweol both give rise to elevation of liver enzymes in healthy volunteers

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    BACKGROUND: Coffee oil potently raises serum cholesterol levels in humans. The diterpenes cafestol and kahweol are responsible for this elevation. Coffee oil also causes elevation of liver enzyme levels in serum. It has been suggested that cafestol is mainly responsible for the effect on serum cholesterol levels and that kahweol is mainly responsible for the effect on liver enzyme levels. The objective of this study was to investigate whether coffee oil that only contains a minute amount of kahweol indeed does not cause elevation of liver enzyme levels. METHODS: The response of serum alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) to Robusta coffee oil (62 mg/day cafestol, 1.6 mg/day kahweol) was measured in 18 healthy volunteers. RESULTS: After nine days one subject was taken off Robusta oil treatment due to an ALAT level of 3.6 times the upper limit of normal (ULN). Another two subjects stopped treatment due to other reasons. After 16 days another two subjects were taken off Robusta oil treatment. One of those subjects had levels of 5.8 ULN for ALAT and 2.0 ULN for ASAT; the other subject had an ALAT level of 12.4 ULN and an ASAT level of 4.7 ULN. It was then decided to terminate the study. The median response of subjects to Robusta oil after 16 days was 0.27 ULN (n = 15, 25(th),75(th )percentile: 0.09;0.53) for ALAT and 0.06 ULN (25(th),75(th )percentile -0.06;0.22) for ASAT. CONCLUSIONS: We conclude that the effect on liver enzyme levels of coffee oil containing hardly any kahweol is similar to that of coffee oil containing high amounts of kahweol. Therefore it is unlikely that kahweol is the component of coffee oil that is responsible for the effect. Furthermore, we conclude that otherwise unexplained elevation of liver enzyme levels observed in patients might be caused by a switch from consumption of filtered coffee to unfiltered coffee

    Dose-escalation using intensity-modulated radiotherapy for prostate cancer - evaluation of quality of life with and without 18F-choline PET-CT detected simultaneous integrated boost

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    <p>Abstract</p> <p>Background</p> <p>In comparison to the conventional whole-prostate dose escalation, an integrated boost to the macroscopic malignant lesion might potentially improve tumor control rates without increasing toxicity. Quality of life after radiotherapy (RT) with vs. without <sup>18</sup>F-choline PET-CT detected simultaneous integrated boost (SIB) was prospectively evaluated in this study.</p> <p>Methods</p> <p>Whole body image acquisition in supine patient position followed 1 h after injection of 178-355MBq <sup>18</sup>F-choline. SIB was defined by a tumor-to-background uptake value ratio > 2 (GTV<sub>PET</sub>). A dose of 76Gy was prescribed to the prostate (PTV<sub>prostate</sub>) in 2Gy fractions, with or without SIB up to 80Gy. Patients treated with (n = 46) vs. without (n = 21) SIB were surveyed prospectively before (A), at the last day of RT (B) and a median time of two (C) and 19 month (D) after RT to compare QoL changes applying a validated questionnaire (EPIC - expanded prostate cancer index composite).</p> <p>Results</p> <p>With a median cut-off standard uptake value (SUV) of 3, a median GTV<sub>PET </sub>of 4.0 cm<sup>3 </sup>and PTV<sub>boost </sub>(GTV<sub>PET </sub>with margins) of 17.3 cm<sup>3 </sup>was defined. No significant differences were found for patients treated with vs. without SIB regarding urinary and bowel QoL changes at times B, C and D (mean differences ≤3 points for all comparisons). Significantly decreasing acute urinary and bowel score changes (mean changes > 5 points in comparison to baseline level at time A) were found for patients with and without SIB. However, long-term urinary and bowel QoL (time D) did not differ relative to baseline levels - with mean urinary and bowel function score changes < 3 points in both groups (median changes = 0 points). Only sexual function scores decreased significantly (> 5 points) at time D.</p> <p>Conclusions</p> <p>Treatment planning with <sup>18</sup>F-choline PET-CT allows a dose escalation to a macroscopic intraprostatic lesion without significantly increasing toxicity.</p

    eRAPID electronic patient self-Reporting of Adverse-events: Patient Information and aDvice: a pilot study protocol in pelvic radiotherapy.

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    Background: An estimated 17,000 patients are treated annually in the UK with radical radiotherapy (RT) for pelvic cancer. New treatment approaches in RT have increased survivorship and changed the subjective toxicity profile for patients who experience acute and long-term pelvic-related adverse events (AE). Multi-disciplinary follow-up creates difficulty for monitoring and responding to these events during treatment and beyond. Originally developed for use in systemic oncology therapy eRAPID (electronic patient self-Reporting of Adverse-events: Patient Information and aDvice) is an online system for patients to report AEs from home. eRAPID enables patient data to be integrated into the electronic patient records for use in clinical practice, provides patient management advice for mild and moderate AE and advice to contact the hospital for severe AE. The system has now been developed for pelvic RT patients, and we aim to test the intervention in a pilot study with staff and patients to inform a future randomised controlled trial (RCT). Methods: Eligible patients are those attending St James's University hospital cancer centre and The Christie Hospital Manchester undergoing pelvic radiotherapy+/-chemotherapy/hormonotherapy for prostate, lower gastrointestinal and gynaecological cancers. A prospective 1:1 randomised (intervention or usual care) parallel group design with repeated measures and mixed methods will be employed. We aim to recruit 168 patients following recommendations for sample size estimates for pilot studies. Participants using eRAPID will report AE (at least weekly) from home weekly for 6 weeks and 6 weeks post-treatment (12-week total) then at 18 and 24 weeks. Hospital staff will review eRAPID reports and use information during consultations. Notifications will be sent to the relevant clinical team when severe symptoms are reported. We will measure patient-reported outcomes using validated questionnaires (Functional Assessment in Cancer Therapy Scale-General (FACT-G), European Organisation for Research and Treatment of Cancer Core Quality of Life questionnaire (EORTC-QLQ-C30), process of care impact (hospital records of patient contacts and admissions) and economic variables (EQ5D-5L, patient use of resources)). Staff and patient experiences will be explored via semi-structured interviews. Discussion: The objectives are to establish feasibility, recruitment, integrity of the system and attrition rates, determine effect sizes and aid selection of the primary outcome measure for a future RCT. We will also refine the intervention by exploring staff and patient views. The overall goal of this complex intervention is to improve the safe delivery of cancer treatments, enhance patient care and standardise documentation of AE within the clinical datasets. Trial registration: ClinicalTrials.gov NCT02747264
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