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Agroforestry (AF) is considered to be a sustainable land use practice as it combines agricultural production with multiple beneficial effects such as carbon sequestration, enhanced nutrient cycling and increased biodiversity. Quantification of these beneficial effects in temperate arable fields is still limited, however, and most studies focus on one sole parameter (i.e., impact on crop productivity, soil quality, biodiversity, etc.). Combined effects are only rarely considered, resulting in a lack of integrated quantification. Here we assess the effect of rows of walnut trees (Juglans regia L.) on soil organic carbon (SOC), soil nutrient status, the presence of potentially beneficial ground-dwelling arthropods and on the yield and quality of neighboring arable crops. Significantly higher SOC and soil nutrient concentrations were found near the trees, which is assumed to be primarily a result of tree leaf litter input. Abundance of macro-detritivorous arthropods was increased in and near the tree rows, whereas only limited effects of tree presence were found on the presence of the predatory arthropod taxa under study. The yield of all crops under study was reduced as a result of tree presence, with the strongest reductions observed for grain maize and sugar beet near the trees (<10 m). In addition, alteration of crop quality was observed near tree rows with decreased dry matter concentration of grain samples and increased crude protein concentration of winter cereals.
In tropical regions the extent of agricultural land is increasing rapidly at the expense of natural forest, with associated losses of biodiversity and ecosystem services. Agroforestry has long been proposed as a more sustainable agricultural system, conserving biodiversity while providing significant local livelihoods. In this context, camera traps were deployed to compare communities of large mammals between natural forest (22,272 hours across 24 deployments) and extensively managed coffee forest (19,059 hours, 23 deployments) for the first time in the south-west Ethiopian highlands. Mammal communities in the two forest types were similar in species richness and Shannon diversity but differed in community composition. Significant indicator species of coffee forest were the crested porcupine Hystrix cristata and the Ethiopian hare Lepus fagani, whereas leopards Panthera pardus and civets Civettictis civetta had a preference for natural forest. The number of detections of mammals was higher in coffee forest, where activity patterns were predominantly crepuscular and nocturnal, which may be a direct adaptation to frequent human disturbance. In natural forest, mammal activity peaked during daytime. Despite the high mammal diversity in extensively managed coffee forest, it cannot fully replace natural forest as a habitat for large mammals. We suggest that a balanced landscape mosaic of coffee and natural forest may be a valuable combination for both conservation and coffee cultivation.
Methodology can play a critical rôle in the measurement of digestion kinetics, especially when the objective is to define kinetic parameters for use in formulating rations or modelling animal responses. Measurement of gas production kinetics provides the opportunity to evaluate the rate of digestion of the soluble, more rapidly fermenting fractions of foods but has the potential for being more sensitive to the in vitro procedure used. Differences among procedures that have little impact on digestion of dry matter after 48 h of incubation, may have dramatic effects on fermentation of soluble matter during the first 20 h. Our objective was to develop a method for measuring the kinetics of gas production that would minimize any detrimental effects associated with the in vitro system and provide estimates of digestion kinetics that can be used to both describe foods for ration formulation systems and provide parameters for models of ruminal digestion.
The kinetics of gas production during ruminal fermentation may provide valuable information about foods that can be used to formulate diets and model animal responses. However, measurement of digestion kinetics is affected by methodology and techniques must be established that provide accurate and precise estimates of kinetic parameters. Because gas production measurements provide the opportunity to estimate the digestion kinetics of both soluble and insoluble matter in foods, it would be desirable to use this technique on a wide variety of forages, grains, supplements, and by-product foods. Applying an in vitro technique to such a wide variety of substrates raises questions about the type of inoculum that should be used. The objective of our study was to evaluate the effects of donor animal and its diet on the measurement of gas production kinetics using both forage and concentrate substrates.
Shifting towards a more sustainable food consumption pattern is an important strategy to mitigate climate change. In the past decade, various studies have optimised environmentally sustainable diets using different methodological approaches. The aim of the present review was to categorise and summarise the different approaches to operationalise the health aspects of environmentally sustainable diets.
Conventional keyword and reference searches were conducted in PubMed, Scopus, Web of Knowledge and CAB Abstracts. Inclusion criteria were: (i) English-language publication; (ii) published between 2005 and October 2015; (iii) dietary data collected for the diet as a whole at the national, household or individual level; (iv) comparison of the current diet with dietary scenarios; and (v) for results to consider the health aspect in some way.
We reviewed forty-nine studies that combined the health and environmental aspects of consumer diets. Hereby, five approaches to operationalise the health aspect of the diet were identified: (i) food item replacements; (ii) dietary guidelines; (iii) dietary quality scores; (iv) diet modelling techniques; and (v) diet-related health impact analysis.
Although the sustainability concept is increasingly popular and widely advocated by nutritional and environmental scientists, the journey towards designing sustainable diets for consumers has only just begun. In the context of operationalising the health aspects, diet modelling might be considered the preferred approach since it captures the complexity of the diet as a whole. For the future, we propose SHARP diets: environmentally Sustainable (S), Healthy (H), Affordable (A), Reliable (R) and Preferred from the consumer’s perspective (P).
Children may be at higher risk for carriage of antimicrobial-resistant bacteria because of higher usage of antimicrobials. They also have higher rates of Shiga toxin-producing Escherichia coli (STEC) infections than other population groups. Some infections, particularly in children, are asymptomatic, but still lead to the excretion of large numbers of bacteria and viruses that may cause clinical disease in other individuals. That is one reason why, in Lower Saxony as in other German federal states – asymptomatic carriers of STEC are excluded from nurseries and schools until three consecutive stool samples test negative in order to prevent secondary cases. The prevalence of children who are asymptomatic STEC carriers is unknown. But if it is high, this measure would have substantial socioeconomic effects on families. Infections with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) are an increasing problem for public health, especially for hospitals. However, there are no reliable estimates of the prevalence of asymptomatic ESBL-E carriers in Lower Saxony, as there is no mandatory requirement to report these carriers. In order to discuss the exclusion policies for children attending nurseries and ascertain a baseline of ESBL-E carriers, we conducted a cross-sectional study. The aim was to determine the prevalence of ESBL-E and STEC and identify risk factors for carriage in nursery children without diarrhoea (asymptomatic) aged 0–6 years in four selected districts in Northern Germany. During April–September 2014, we collected stool specimens with the support of voluntarily participating nurseries. We tested for STEC by PCR and for ESBL-E on chromogenic agar. Questionnaires answered by parents contained data on eating and drinking habits, outdoor activities, prior antibiotic treatment and animal contact for each participating child. We compared the epidemiological characteristics of ESBL-E carriers vs. non-carriers by using univariable analysis (P value, odds ratio and 95% confidence interval). We could not perform a statistical analysis for STEC carriers due to the low numbers of positive STEC specimens. Of 224 asymptomatic nursery children, we found a prevalence of 2·3% for ESBL-E carriage and 0·5% for STEC carriage. Asymptomatic ESBL-E carriers were more likely to have consumed raw milk, have had contact with pet rodents, or to have taken antibiotics during the preceding 6 months. We also found a high proportion of raw milk consumption (11%). We suggest that the low STEC prevalence in asymptomatic children supports the current practice of excluding STEC carriers from nurseries. The association between ESBL-E carriage and raw milk consumption and contact with pet rodents needs further investigation.
The influence of ambient fluid stratification on buoyant miscible jets and plumes is studied theoretically and experimentally. Given a fixed set of jet/plume parameters, and an ambient fluid stratification sandwiched between top and bottom homogeneous densities, a theoretical criterion is identified to show how step-like density profiles constitute the most effective mixers within a broad class of stable density transitions. This is assessed both analytically and experimentally, respectively by establishing rigorous a priori estimates on generalized Morton–Taylor–Turner (MTT) models (Morton et al., Proc. R. Soc. Lond. A, vol. 234, 1956, pp. 1–23; Fischer et al., Mixing in Inland and Coastal Waters. Academic, 1979), and by studying a critical phenomenon determined by the distance between the jet/plume release height with respect to the depth of the ambient density transition. For fluid released sufficiently close to the background density transition, the buoyant jet fluid escapes and rises indefinitely. For fluid released at locations lower than a critical depth, the buoyant fluid stops rising and is trapped indefinitely. A mathematical formulation providing rigorous estimates on MTT models is developed along with nonlinear jump conditions and an exact critical-depth formula that is in good quantitative agreement with the experiments. Our mathematical analysis provides rigorous justification for the critical trapping/escaping criteria, first presented in Caulfield & Woods (J. Fluid Mech., vol. 360, 1998, pp. 229–248), within a class of algebraic density decay rates. Further, the step-like background stratification is shown to be the most efficient mixing profile amongst a broad family of stably stratified profiles sharing the same density transition within a fixed distance. Finally, the analysis uncovers surprising differences between the Gaussian and top-hat profile closures concerning initial mixing of the jet and ambient fluid.
To tackle the high prevalence of lameness, techniques to monitor cow locomotion are being developed in order to detect changes in cows’ locomotion due to lameness. Obviously, in such lameness detection systems, alerts should only respond to locomotion changes that are related to lameness. However, other environmental or cow factors can contribute to locomotion changes not related to lameness and hence, might cause false alerts. In this study the effects of wet surfaces, dark environment, age, production level, lactation and gestation stage on cow locomotion were investigated. Data was collected at Institute for Agricultural and Fisheries Research research farm (Melle, Belgium) during a 5-month period. The gait variables of 30 non-lame and healthy Holstein cows were automatically measured every day. In dark environments and on wet walking surfaces cows took shorter, more asymmetrical strides with less step overlap. In general, older cows had a more asymmetrical gait and they walked slower with more abduction. Lactation stage or gestation stage also showed significant association with asymmetrical and shorter gait and less step overlap probably due to the heavy calf in the uterus. Next, two lameness detection algorithms were developed to investigate the added value of environmental and cow data into detection models. One algorithm solely used locomotion variables and a second algorithm used the same locomotion variables and additional environmental and cow data. In the latter algorithm only age and lactation stage together with the locomotion variables were withheld during model building. When comparing the sensitivity for the detection of non-lame cows, sensitivity increased by 10% when the cow data was added in the algorithm (sensitivity was 70% and 80% for the first and second algorithm, respectively). Hence, the number of false alerts for lame cows that were actually non-lame, decreased. This pilot study shows that using knowledge on influencing factors on cow locomotion will help in reducing the number of false alerts for lameness detection systems under development. However, further research is necessary in order to better understand these and many other possible influencing factors (e.g. trimming, conformation) of non-lame and hence ‘normal’ locomotion in cows.
The synthesis and texturization processes of fluorinated surfaces by means of atmospheric plasma are investigated and presented through an integrated study of both the plasma phase and the resulting material surface. Three methods enhancing the surface hydrophobicity up to the production of super-hydrophobic surfaces are evaluated: (i) the modification of a polytetrafluoroethylene (PTFE) surface, (ii) the plasma deposition of fluorinated coatings and (iii) the incorporation of nanoparticles into those fluorinated films. In all the approaches, the nature of the plasma gas appears to be a crucial parameter for the desired property. Although a higher etching of the PTFE surface can be obtained with a pure helium plasma, the texturization can only be created if O2 is added to the plasma, which simultaneously decreases the total etching. The deposition of CxFy films by a dielectric barrier discharge leads to hydrophobic coatings with water contact angles (WCAs) of 115°, but only the filamentary argon discharge induces higher WCAs. Finally, nanoparticles were deposited under the fluorinated layer to increase the surface roughness and therefore produce super-hydrophobic hybrid coatings characterized by the nonadherence of the water droplet at the surface.
Background: Foetuses with simple tetralogy of Fallot almost universally have a patent ductus arteriosus. Two recently identified cases had an absent patent ductus arteriosus, requiring emergent intervention at birth. The objective of this study was to determine whether foetuses diagnosed with tetralogy of Fallot and no patent ductus arteriosus have poorer outcomes compared with those with tetralogy of Fallot+patent ductus arteriosus. Methods: All foetal cases of tetralogy of Fallot between January, 2000 and 2012 were retrospectively identified from The Hospital for Sick Children (Toronto, Canada) database. Cases – tetralogy of Fallot+no patent ductus arteriosus confirmed on postnatal echo – and controls – tetralogy of Fallot+patent ductus arteriosus, matched for gestational age – were identified from prenatal records, and both clinical and echocardiographic data were reviewed. Optimal outcome was defined as valve-sparing repair with no residual lesions. Student’s t-tests and Fisher’s exact χ2 were used to compare groups. Results: n=115 foetuses were diagnosed with tetralogy of Fallot: 11 (9%) had no patent ductus arteriosus, and were matched to 22 controls – mean gestational age at diagnosis 23.2±4.2 weeks, 23.4±6.6 weeks, respectively. Cases had a higher proportion of right aortic arches (64% versus 14%, p<0.001). Foetal and postnatal echocardiographic data did not reveal significant differences in branch pulmonary artery sizes, pulmonary valve sizes, or ventricular function. No differences were identified for cyanosis at birth (2/10 versus 7/20, p=0.67), or catheter intervention (5/10 versus 4/22, p=0.12). Optimal outcome rates were similar between cases and controls (4/11 (36%) versus 5/21 (24%), p=0.68). Conclusions: The patent ductus arteriosus does not appear to have an impact on clinical outcome in foetuses with tetralogy of Fallot.
The hen's egg, in the form of table eggs and egg products, forms a staple part of the world's total protein consumption. In the last century, there has been considerable research effort focusing on ways of improving egg production and enhancing the quality of eggs. More recently, and with the development and application of new molecular technologies, our understanding and knowledge of how an egg is formed, what it actually consists of, in terms of its major versus minor components, and what the functional roles of each of these components might be, have been greatly enhanced. For example, new previously unknown molecules with specific activity or functional properties have been discovered in the egg albumen and yolk, some of which have potential uses in pharmaceutical and other food related applications. This review paper, which is the collaborative effort of members of Working Group 4 - Quality of Eggs and Egg Products - of the European Federation of WPSA, describes the scientific research behind a number of these major advances and provides some insight to the focus of current research in this area.
In order to understand how N2 plasma conditions impact on the incorporation of nitrogen species into a thin SiO2 (1.4 nm), tuning of some pulsed RF (pRF) Decoupled Plasma Nitridation (DPN) process parameters was performed: duty cycle (DC) or on-time per period, frequency (f), process time (t) and some cross-combinations (DC*f, DC*t, DC*f*t). The N2 plasma and the SiOx Ny film were characterized using Langmuir probe analysis (LP) and Delay to Reoxidation (D2R) techniques, respectively. Correlations are established between ion density and electron temperature and the resultant nitrogen concentration and parasitic physical thickness increase. The LP results indicate that while DC impacts the ion density and energy, the frequency has no impact to first order. This is consistent with the physical characteristics of the film. From the combination of DC*f*t, the importance of the off-time portion of the pulse was revealed. With the help of a modified pulsed RF DPN generator, allowing a decrease of the frequency down to 2 kHz, a 5% improvement of the drive current for pMOS transistors was obtained.
We have calculated J-V characteristics of an organic conducting sample (containing traps) including the Poole-Frenkel Effect (PFE). Both shallow and exponentially distributed traps are considered. We show that our approach is equivalent to combining the effect of trapping and using the field dependent mobility in one unified model. For shallow single level or shallow Gaussian traps, inclusion of PFE or using the (well-known) field dependent mobility gives the same dependence of current on voltage at a given temperature. However the value of zero field mobility µ0 comes out to be different. We have fabricated and measured the J-V curves of the ITO/MEH-OPV5/Al diodes. An extremely fast rise with voltage V is observed at small voltages, which can be interpreted either by the Schottky contact limited Shockley like current or by bulk space charge limited current with PFE. The correct mechanism can be determined by making J-V measurements at different temperatures.
Superconducting Y—Ba—Cu—O thin films with critical temperatures exceeding 80 K are deposited on silicon single crystal substrates using the pulsed laser deposition technique. Deposition from a sintered Y1 Ba2Cu3O7‐ target in oxygen ambient of 0.1 — 5 mbar onto substrates kept at 700°C to 820°C results in crystalline films in which the target composition of the metallic constituents is preserved. No post deposition treatments are required to obtain high values for the zero resistance. X— ray analysis as well as Raman spectroscopy reveal that specimens prepared at optimum conditions are single phase c—axis oriented. In contrast to films prepared on LaAlO3 or SrTiO3 the surface morphology shows a granular structure. The films prepared by this technique are quite stable against chemicals used in conventional lithographic patterning, however, a strong correlation between film quality before patterning and some degradation after patterning is observed.
For the first time an operating heterojunction bipolar silicon transistor has been realized with phosphorous doped amorphous silicon (a-Si) emitter. The deposition of a-Si is a relatively simple technique. The current gain (β) of 14 at a base Gummel Number (G.N.) of 1.35 1013 s/cm4 is higher than that obtained with normal diffused emitter bipolar transistors with the same G.N. for the base. This adds a degree of freedom to the design of bipolar structures according to the compromise between base resistance and current gainCrucial points that have to be looked at further are interface recombination at the a-Si/c-Si transition and emitter resistance.
The behavior of Si and Be impurities in InAsx Sb1−x (0.05<x<0.45) heteroepitaxial layers grown on GaAs-coated Si by MBE is characterised. Siis found to act as an n-type dopant for the growth conditions used. The calibration of the Si n-type doping as a function of the Sisource temperature is obtained by infrared absorption spectrometry, stripping Hall and SIMS depth profiling. At high doping levels the amphoterical characterof the Si impurities becomes evident. SIMS is used to investigate the dopant incorporation and the formation of diode structures. The influence of the mismatched epitaxy on the transport properties is investigated by stripping Hall measurements. In order to establish the correlation between crystalline properties of the epilayers and the ability to fabricate diodes, we compare the defect structure of InAs and In(As)Sb p-'i'-n diodes.
In this paper phosphorous doped amorphous and microcrystalline silicon are used as emitter material for npn bipolar transistors. A heterojunction is formed between emitter and base, resulting in a higher current gain β for the same base parameters in comparison with conventional transistors. Because the amorphous silicon results in a too high emitterresistance, a compromise solution is microcrystalline silicon (μc-Si). HREM-micrographs give credit to the true heterojunction concept and show epitaxial reorganization, especially after annealing of the amorphous silicon.
The characteristics of the HF-treated Si-surface are investigated as a function of dipping time in dilute HF solutions. It is found that the contact angle is a very sensitive measure for the degree of oxidation of the Si-surface. The importance of obtaining a perfectly passivated surface in order to reduce the particle deposition on the surface is shown. HF-last cleans are found to be beneficial in terms of metallic contamination and gate oxide integrity. The importance of the loading ambient in furnaces is investigated after HF-treatments and RCA-cleans.
One of the applications of high dose ion implantation is to form surface
alloys or compound layers. The detailed characterization of such composite
structures is of great importance. This paper tries to answer the question:
how can we outline, at least, a qualitative picture from the optical
properties measured by ellipsometry of high dose Al and Sb implanted
silicon. Attempts are done to separate the effect of implanted impurities
from the dominant disorder contribution to the measured optical properties.
As the ellipsometry does not provide information enough to decide the
applicability of optical models therefore methods sensitive to the structure
(channeling and TEM) were applied too.