Influence of cane girdling and plastic covering on leaf gas exchange, water potential and viticultural performance of table grape cv. Matilde

Canes of field-grown uncovered and covered (plastic film) table grapes, cv. Matilde, were girdled at veraison. Leaves of girdled vines displayed lower rates of transpiration on a leaf area basis and lower rates of CO2 uptake; stem and leaf water potentials were decreased. Both, covering and cane girdling stimulated vegetative growth and increased leaf area per vine. However, sugar accumulation in berries and fruit quality were not affected by cane girdling and were slightly reduced by covering. Therefore, harvesting dates were not advanced. Cane girdling appeared to influence carbohydrate partitioning by stimulating shoot growth at the expense of fruit production. It is concluded that the stage of rapid sugar accumulation was not yet reached by the time girdling took place. The development of a larger transpiring leaf surface area per vine is supposed to have lowered the vine water status

Enabling Self-Powered Autonomous Wireless Sensors with New-Generation I2C-RFID Chips

A self-powered autonomous RFID device with sensing and computing capabilities is presented in this paper. Powered by an RF energy-harvesting circuit enhanced by a DC-DC voltage booster in silicon-on-insulator (SOI) technology, the device relies on a microcontroller and a new generation I2C-RFID chip to wirelessly deliver sensor data to standard RFID EPC Class-1 Generation-2 (Gen2) readers. When the RF power received from the interrogating reader is -14 dBm or higher, the device, fabricated on an FR4 substrate using low-cost discrete components, is able to produce 2.4-V DC voltage to power its circuitry. The experimental results demonstrate the effectiveness of the device to perform reliable sensor data transmissions up to 5 meters in fully-passive mode. To the best of our knowledge, this represents the longest read range ever reported for passive UHF RFID sensors compliant with the EPC Gen2 standard

Experimental evidence of delocalized states in random dimer superlattices

We study the electronic properties of GaAs-AlGaAs superlattices with intentional correlated disorder by means of photoluminescence and vertical dc resistance. The results are compared to those obtained in ordered and uncorrelated disordered superlattices. We report the first experimental evidence that spatial correlations inhibit localization of states in disordered low-dimensional systems, as our previous theoretical calculations suggested, in contrast to the earlier belief that all eigenstates are localized.Comment: 4 pages, 5 figures. Physical Review Letters (in press

Orchard floor management affects tree functionality, productivity and water consumption of a late ripening peach orchard under semi-arid conditions

Semi-arid conditions are favorable for the cultivation of late ripening peach cultivars; however, seasonal water scarcity and reduction in soil biological fertility, heightened by improper soil management, are jeopardizing this important sector. In the present two-year study, four soil managements were compared on a late ripening peach orchard: (i) completely tilled (control); (ii) mulched with reusable reflective plastic film; (iii) mulching with a Leguminosae cover-crop flattened after peach fruit set; (iv) completely tilled, supplying the water volumes of the plastic mulched treatment, supposed to be lower than the control. Comparison was performed for soil features, water use, tree functionality, fruit growth, fruit quality, yield and water productivity. Even receiving about 50% of the regular irrigation, reusable reflective mulching reduced water loss and soil carbon over mineralization, not affecting (sometimes increasing) net carbon assimilation, yield, and fruit size and increasing water productivity. The flattening technique should be refined in the last part of the season as in hot and dry areas with clay soils and low organic matter, soil cracking increased water evaporation predisposing the orchard at water stress. The development and implementation of appropriate soil management strategies could be pivotal for making peach production economically and environmentally sustainable

04/15/1985 - Weekly Preview Review

Conventional RFID readers combine transmission (to the tag) and reception (from the tag) functions in a single physical device. In this paper we discuss the design and potential applications of a receive-only device, called "RFID listener", that decodes the signals from both the tag and the reader. This enables augmented RFID systems where one transmitter coexists with multiple listeners offering reception redundancy and diversity. We present a Software-Defined Radio (SDR) implementation of an RFID listener compliant with Gen2 standard, which can serve as a research tool for experimenting "on air" novel augmented RFID systems. Moreover, our listener can be used as a flexible and cheap protocol analyzer for conventional reader/tag systems. We present a test-bed setting where our listener and a conventional SDR reader are used in conjunction to measure separately the maximum downlink and uplink range. © 2011 IEEE

Wireless resonant energy link for pulse generators implanted in the chest

This study investigates the feasibility of using the MedRadio band for wirelessly transmitting power to a rechargeable medical device implanted in the chest. In particular, a wireless energy link operating at 403 MHz and based on an inductive coupling between two planar resonators is considered, and its performance is assessed through simulations and experimental tests. Results show that a maximum value of the measured power transfer efficiency of ~23% is achieved. Furthermore, the possibility of using the link for recharging a lithium-ion battery of a pulse generator implanted in the chest at a depth of 5 mm is discussed, and the compliance with safety regulations is verified. Reported results demonstrate that the proposed link can be used to charge a lithium-ion battery with a capacity up to 7.2 mAh, while inducing a peak of the specific absorption rate averaged over 1 g of tissue < 1.6 W/kg

A Probiotic-Based Sanitation System for the Reduction of Healthcare Associated Infections and Antimicrobial Resistances: A Budget Impact Analysis

Healthcare Associated Infections (HAIs) and antibiotic resistance have high social and economic burdens. Healthcare environments play an important role in the transmission of HAIs. The Probiotic Cleaning Hygiene System (PCHS) showed to decrease hospital surface pathogens up to 90% vs. conventional chemical cleaning (CCC). This study compares PCHS to CCC as to reduction of HAIs and their severity, related antibiotic resistances, and costs. Incidence rates of HAIs/antibiotic resistances were estimated from a multicenter pre-post (6 months CCC + 6 months PCHS) intervention study after applying propensity score matching technique. A budget impact analysis compared the current scenario of use of CCC with future scenarios considering increasing utilization of PCHS, from 5% to 50% in the next five years, from the hospital perspective in Italy. The cumulative incidence of HAI was 4.6% and 2.4% (p <0.0001) for CCC (N=4,160) and PCHS (N=4,160) (OR = 0.47, CI 95% 0.37-0.60), with severe HAIs of 1.57% vs 1% and antibiotic resistances of 1.13% vs 0.53%, respectively. Increased use of PCHS over CCC in Italian internal medicine/geriatrics and neurology departments in the next 5 years is expected to avert at least about 31,000 HAIs and 8,500 antibiotic resistances, and save at least 14 million Euros, of which 11.6 for the treatment of resistant HAIs. Innovative, environmentally sustainable sanitation systems, like PCHS, might substantially reduce antibiotic resistance and increase protection of health worldwide