195 research outputs found
Creation of Controlled Defects Inside Colloidal Crystal Arrays with a Focused Ion Beam
In this work the reliability of the focused-ion-beam (FIB) patterning on polystyrene (PS) colloidal crystals at different scales is determined. Ordered arrays of PS spheres (465 nm) are successfully modified by selectively removing a single sphere. The water-vapor assisted FIB milling is crucial to obtain this result. Furthermore, isolated PS spheres are FIB drilled with or without chemically enhanced milling aiming at the exploration of the limits of such a technique. These controlled defects created using the FIB-assisted techniques may be helpful in preparing mockups of photonic crystals, sensors or as colloidal masks for diverse lithographic processes
A nonparametric approach for model individualization in an artificial pancreas
The identification of patient-tailored linear time invariant glucose-insulin models is investigated for type 1 diabetic patients, that are characterized by a substantial inter-subject variability. The individualized linear models are identified by considering a novel kernel-based nonparametric approach and are compared with a linear time invariant average model in terms of prediction performance by means of the coefficient of determination, fit, positive and negative max errors, and root mean squared error. Model identification and validation are based on in-silico data collected from the adult virtual population of the UVA/Padova simulator. The data generation involves a protocol designed to produce a sufficient input excitation without compromising patient safety, compatible also with real life scenarios. The identified models are exploited to synthesize an individualized Model Predictive Controller (MPC) for each patient, which is used in an Artificial Pancreas to maintain the blood glucose concentration within an euglycemic range. The MPC used in several clinical studies, synthesized on the basis of a non-individualized average linear time invariant model, is also considered as reference. The closed-loop control performance is evaluated in an in-silico study on the adult virtual population of the UVA/Padova simulator in a perturbed scenario, in which the MPC is blind to random variations of insulin sensitivity in each virtual patient. © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved
Carbohydrate content, characterization and localization in bermudagrass stolons during establishment
Abstract Turfgrasses are continuously exposed to a wide range of detrimental stresses, such as mowing, traffic, low or high temperatures, salinity, drought, UV, hypoxia etc. Plant responses to stimuli involve nearly every aspect of plant physiology and metabolism. Carbohydrates, primary sucrose and starch, as principal metabolic products of photosynthesis, are stored in bermudagrass (Cynodon spp.) in stolons and rhizomes. Total nonstructural carbohydrates (TNC) levels have been used as indicators of health and physiological status in bermudagrass. TNC levels vary during the year and are weakly affected by N source. Establishment is a critical phase of bermudagrass management. The objectives of this research were to assess and characterize stolon carbohydrate content in nine bermudagrass cultivars during the full establishment phase in relation to establishment rates. Morphological and growth analyses showed distinct properties among the cultivars selected for this study. Significant differences in turf co..
Statistical analysis of correlations and intermittency of a turbulent rotating column in a magnetoplasma device
12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France)A detailed statistical analysis of density fluctuations in the cylindrical non-fusion device "Mistral" is performed. The experimental set-up is implemented in order to reach turbulent behavior in the rotating plasma column. Two different turbulent regimes are obtained corresponding to two selected sets of values for the anode potential and the biasing of the collecting plate. The first regime displays a slowly-rotating column characterized by the presence of a shear layer separating the plasma bulk from the scrape-off layer (SOL), the latter showing a strong intermittent behavior. The second regime corresponds to a weakly-rotating column in which coherence is lost in the plasma bulk and a standard diffusive process takes place in the SOL. These findings are supported by the calculation of the Hurst exponent of the turbulent signals using Wavelet-analysis techniques
Comparison of Oxford Cognitive Screen and Montreal Cognitive Assessment feasibility in the stroke unit setting. A pilot study
Background: : Cognitive status evaluation is not routine in the acute stroke setting and there is no consensus on which neuropsychological tool is more feasible and informative. The aim of this pilot study was to compare the feasibility and acceptability of two brief cognitive tests, the Montreal Cognitive Assessment (MoCA) and the Oxford Cognitive Screen (OCS), in acute stroke, with a focus on patients' experience, administration time, and the cognitive data obtained. Methods: : Patients with a diagnosis of ischemic or hemorrhagic stroke or of transient ischemic attack admitted to two stroke units were included. The sample consisted of 34 participants (mean age ±SD 71.1 ± 16.1 years, 25 males). Within five days of onset, patients were evaluated by means of the MoCA and OCS by a trained neuropsychologist. Results: Both tests were feasible in the stroke unit setting and had a high level of acceptability by patients. MoCA test was fully completed by 25 patients, OCS by 21 patients. The OCS administration time was longer than that of the MoCA. However, OCS was perceived less demanding than MoCA by patients. Twenty patients completed both the MoCA and the OCS entirely, and only 2 of them did not show any impairment in both tests. Seventeen patients showed at least an impaired domain on the OCS and 15 patients presented with a MoCA global score below cut-off for cognitive impairment. Conclusions: Our preliminary study did not show a superiority of the OCS over the widely used MoCA, and suggests the need for further validation in larger samples of stroke patients, exploring tests accuracy in detecting cognitive post-stroke impairment
Spectral Reflectance of Tall Fescue (Festuca Arundinacea Schreb.) Under Different Irrigation and Nitrogen Conditions
The issue of water and climate change is present in many countries. Drought stress is one of the main abiotic stresses influencing turfgrass growth and quality. Tall fescue is the most suitable cool-season turfgrass for the Mediterranean region. This species has a better heat tolerance than perennial ryegrass and Kentucky bluegrass. The analysis of radiation reflected by turfgrass can supply precious information on drought stress and nutritional status. In this study a Linear Gradient Irrigation System (LGIS) was adopted on a Festuca arundinacea turf with 9 water replenishment levels and 2 nitrogen conditions, to evaluate the proximity sensed spectral reflectance. ET0 was estimated using the Hargreaves and Samani method. The following parameters
were determined: turf quality, drought tolerance, pest problems, temperature of the surface, clippings weight and relative nitrogen content, turf growth and soil moisture. Spectral reflectance data were acquired using a LICOR 1800 spectroradiometer. Pearson correlation coefficients were studied among all parameters and vegetation indices. Nitrogen fertilization influenced
significantly turf quality, clippings weight, nitrogen content and turf growth. Water replenishment influenced significantly all parameters except nitrogen content. Among all parameters the highest correlation coefficient was registered relating drought tolerance with turf quality (r = 0.88) and with surface temperature (r = - 0.88). Among vegetation indices results showed that
Water Index (WI) and Normalized Difference Water Index (NDWI), are the most suitable to discriminate between different levels of water replenishment. Comparing WI with NDWI, the correlation coefficients were higher for Water Index in all the parameters, in particular the highest WI value was registered for drought tolerance (r = 0.91). This preliminary research demonstrates that spectral remote sensing can be a useful diagnostic tool to detect water stress in turfgrasses
The Role of Micronutrients in Human Papillomavirus Infection, Cervical Dysplasia, and Neoplasm
There is evidence that diet and nutrition are modifiable risk factors for several cancers. In recent years, attention paid to micronutrients in gynecology has increased, especially regarding Human papillomavirus (HPV) infection. We performed a review of the literature up until December 2022, aiming to clarify the effects of micronutrients, minerals, and vitamins on the history of HPV infection and the development of cervical cancer. We included studies having as their primary objective the evaluation of dietary supplements, in particular calcium; zinc; iron; selenium; carotenoids; and vitamins A, B12, C, D, E, and K. Different oligo-elements and micronutrients demonstrated a potential protective role against cervical cancer by intervening in different stages of the natural history of HPV infection, development of cervical dysplasia, and invasive disease. Healthcare providers should be aware of and incorporate the literature evidence in counseling, although the low quality of evidence provided by available studies recommends further well-designed investigations to give clear indications for clinical practice
Autonomous rotary mower versus ordinary reel Mower-effects of cutting height and nitrogen rate on manila grass turf quality
High-quality sports turfs often require low mowing and frequent
maintenance. Sports turfs often consist of hard-to-mow warm season turfgrasses,
such as zoysiagrass (Zoysia sp.) or bermudagrass (Cynodon sp.). Although autonomous
mowers have several advantages over manually operated mowers, they are not
designed to mow lower than 2.0 cm and are consequently not used on high-quality
sports turfs. All autonomous mowers are only equipped with rotary mowing devices
and do not perform clipping removal. An ordinary autonomous mower was
modified to obtain a prototype autonomous mower cutting at a low height. The
prototype autonomous mower was tested on a manila grass (Zoysia matrella) turf
and compared its performance in terms of turf quality and energy consumption with
an ordinary autonomous mower and with a gasoline reel mower. A three-way factor
experimental design with three replications was adopted. Factor A consisted of four
nitrogen rates (0, 50, 100, and 150 kghaL1), factor B consisted of two mowing
systems (autonomous mower vs. walk-behind gasoline reel mower with no clipping
removal), and factor C consisted of two mowing heights (1.2 and 3.6 cm).
Prototype autonomous mower performed mowing at 1.2-cm mowing height
whereas ordinary autonomous mower mowed at 3.6-cm mowing height. The
interaction between the mowing system and mowing height showed that the turf
quality was higher when the turf was mowed by the autonomous mower and at
1.2 cm than at 3.6 cm. Autonomous mowing not only reduced the mowing quality,
but also reduced the leaf width. Lower mowing height induced thinner leaves.
Nitrogen fertilization not only increased the overall turf quality, reduced weed
cover percentage, but also reduced mowing quality. Autonomous mowers also had
a lower energy consumption if compared with the reel mower (1.86 vs. 5.37 kWh/
week at 1.2-cm mowing height and 1.79 vs. 2.32 kWh/week at 3.6-cm mowing
height, respectively). These results show that autonomous mowers can perform low
mowing even on tough-to-mow turfgrass species. They could also be used on highquality
sports turfs, thus saving time as well as reducing noise and pollution
Use of Flaming to Control Weeds in ‘Patriot’ Hybrid Bermudagrass
Flaming could be an alternative to the use of chemical herbicides for
controlling weeds in turfgrass. In fact, the European Union has stipulated that
chemical herbicides should be minimized or prohibited in public parks and gardens,
sports and recreational areas, school gardens, and children’s playgrounds. The aim
of this research was to test different doses of liquefied petroleum gas (LPG) to find
the optimal flaming dose that keeps a ‘Patriot’ hybrid bermudagrass (Cynodon
dactylon · Cynodon transvaalensis) turf free of weeds during spring green-up, but
also avoids damaging the grass. Five LPG doses (0, 29, 48, 71, and 100 kgha–1)
were applied in a broadcast manner over the turf experimental units using a selfpropelled
flaming machine. This equipment is commercially available and usable by
turfgrass managers. Treatments were applied three times during the spring to allow
the maximum removal of weeds from the turfgrass. Data on weed coverage, density,
biomass, and turfgrass green-up were collected and analyzed. Results showed that 3
weeks after the last flaming, the greatest LPG doses used (i.e., 71 and 100 kgha–1)
ensured the least amount of weeds (range, 5–16 weeds/m2) of low weight (range, 7–
60 gm–2) and a low weed cover percentage (range, 1% to 5%), whereas the green
turfgrass coverage was high (range, 82% to 94%). At the end of the experiment, the
main weed species were horseweed (Conyza canadensis), field bindweed (Convolvulus
arvensis), narrow-leaved aster (Aster squamatus), and black medic (Medicago
lupulina). Flame weed control is a promising technique to conduct weed control in
turfgrass. Further studies could be conducted to investigate the use of flaming in
other species of warm-season turfgrasses
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