Health Planner Pigs as an Instrument for Monitoring and Evaluation of Animal Health Care on Pig Farms

In order to support animal health care on pig farms a Health Planner Pigs has been developed. In 1998 the practical value of the system was tested under field condition on pig farms. The Health Planner proved to be a valuable instrument for monitoring and evaluating animal health on pig farms. Due to the promising results of the field experiment, the Dutch Farmers Organisation (LTO-Nederland) in 1999 adopted the system and coordinates its adaptation and introduction into practice. In 2001, veterinarians and farm advisers has been educated in using the Health Planner. Some parts of the Health Planner will be automised and linked to existing farm management information systems. In 2002, farmers will be educated in the use of it.Farm Management, Livestock Production/Industries,

The extent to which weeds modify the transpiration of cereals

This work on transpiration involved a study of the competition and the comparison of the growth of wheat, of wheat with mustard, of oats alone and oats with mustard. To determine the growth and development taking place in the various cultures, measurements were made at frequent intervals of the increases in leaf area and of the amount of water lost. The data clearly show that weeds require a large amount of water. Comparing the pure and mixed cultures leaves no doubt but that a weed like mustard impairs the crop. The effect is evidenced in the fact that a culture of wheat and mustard attained its maximum leaf area later than a culture which contained only wheat; cultures of oats and mustard attained maximum leaf area later than cultures of oats alone. The results secured indicate that such a procedure will cut down the dry weight produced. It is brought out that where oats are grown thick enough, they will offer a competition between themselves. Such growth, however, offers better means for the eradication of weeds like mustard by the process of competition. From the results presented in this work, oats in all probability would be better for this purpose than wheat

One-second coherence for a single electron spin coupled to a multi-qubit nuclear-spin environment

Single electron spins coupled to multiple nuclear spins provide promising multi-qubit registers for quantum sensing and quantum networks. The obtainable level of control is determined by how well the electron spin can be selectively coupled to, and decoupled from, the surrounding nuclear spins. Here we realize a coherence time exceeding a second for a single electron spin through decoupling sequences tailored to its microscopic nuclear-spin environment. We first use the electron spin to probe the environment, which is accurately described by seven individual and six pairs of coupled carbon-13 spins. We develop initialization, control and readout of the carbon-13 pairs in order to directly reveal their atomic structure. We then exploit this knowledge to store quantum states for over a second by carefully avoiding unwanted interactions. These results provide a proof-of-principle for quantum sensing of complex multi-spin systems and an opportunity for multi-qubit quantum registers with long coherence times

Polarization-preserving confocal microscope for optical experiments in a dilution refrigerator with high magnetic field

We present the design and operation of a fiber-based cryogenic confocal microscope. It is designed as a compact cold-finger that fits inside the bore of a superconducting magnet, and which is a modular unit that can be easily swapped between use in a dilution refrigerator and other cryostats. We aimed at application in quantum optical experiments with electron spins in semiconductors and the design has been optimized for driving with, and detection of optical fields with well-defined polarizations. This was implemented with optical access via a polarization maintaining fiber together with Voigt geometry at the cold finger, which circumvents Faraday rotations in the optical components in high magnetic fields. Our unit is versatile for use in experiments that measure photoluminescence, reflection, or transmission, as we demonstrate with a quantum optical experiment with an ensemble of donor-bound electrons in a thin GaAs film.Comment: 9 pages, 7 figure

Clinical Utility of the Cardiorespiratory Optimal Point in Patients with Heart Failure

Introduction We assessed the cardiorespiratory optimal point (COP)—the minimal V̇E/V̇O2 in a given minute of an incremental cardiopulmonary exercise test—in patients with heart failure (HF) and aimed to determine 1) its association with patient and disease characteristics, 2) changes after an exercise-based cardiac rehabilitation program (CR), and 3) the association with clinical outcomes. Methods We studied 277 HF patients (67 (58–74) yr, 30% female, 72% HF with restricted ejection fraction) between 2009 and 2018. Patients participated in a 12- to 24-wk CR program, and COP was assessed pre- and post-CR. Patient and disease characteristics and clinical outcomes (mortality and cardiovascular-related hospitalization) were extracted from patient files. The incidence of clinical outcomes was compared across COP tertiles (low, 30.7). Results Median COP was 28.2 (24.9–32.1) and was reached at 51% ± 15% of V̇O2peak. Lower age, female sex, higher body mass index, the absence of a pacemaker or the absence of chronic obstructive pulmonary disease, and lower N-terminal prohormone brain natriuretic peptide concentrations were associated with a lower COP. Participation in CR reduced COP (−0.8; 95% confidence interval, −1.3 to −0.3). Low COP had a reduced risk (adjusted hazard ratio, 0.53; 95% confidence interval, 0.33–0.84) for adverse clinical outcomes as compared with high COP. Conclusions Classic cardiovascular risk factors are associated with a higher, more unfavorable, COP. CR-based exercise training reduces COP, whereas a lower COP is associated with a better clinical prognosis. As COP can be established during a submaximal exercise test, this may offer novel risk stratification possibilities for HF care programs.Eurostars Grant (E!114585

Electromagnetically Induced Transparency with an Ensemble of Donor-Bound Electron Spins in a Semiconductor

We present measurements of electromagnetically induced transparency with an ensemble of donor- bound electrons in low-doped n-GaAs. We used optical transitions from the Zeeman-split electron spin states to a bound trion state in samples with optical densities of 0.3 and 1.0. The electron spin dephasing time T* \approx 2 ns was limited by hyperfine coupling to fluctuating nuclear spins. We also observe signatures of dynamical nuclear polarization, but find these effects to be much weaker than in experiments that use electron spin resonance and related experiments with quantum dots.Comment: 4 pages, 4 figures; Improved analysis of data in Fig. 3, corrected factors of 2 and p

Naar een nieuwe Na-behoefte norm voor melkvee en verantwoorde Na-bemesting op grasland

Natrium is van invloed op de smakelijkheid van gras en daarmee op de grasopname en mogelijk ook op de melkproductie. Uit buitenlandse literatuur blijkt dat de drogestof opname het hoogst is bij een Na-gehalte tussen 2,5 – 5,5 g per kg ds, wat fors hoger is dan de fysiologische behoefte. Onder Nederlandse omstandigheden zijn echter geen experimentele gegevens voorhanden over de optimale Na-gehalten van gras. Anderzijds is het huidige bemestingsadvies verouderd, omdat dat alleen rekening houdt met de K- en Na-toestand van de grond, terwijl bekend is dat ook de bemesting met N, K, Na en Mg en de Mg-toestand van invloed kan zijn op het Na-gehalte in gras. Door rekening te houden met multi-nutriënt interacties kan een meer op maat Na-advies worden ontwikkeld waar mee gericht is te sturen op een gewenst Na-gehalte in gras. NMI en ASG hebben in een gezamenlijke studie in opdracht van Productschap Zuivel daarop onderzoek uitgevoerd i) voor de ontwikkeling van een nieuw Na-bemestingsadvies op basis van monitoring en praktijkproeven en ii) voor het bepalen van het optimale Na-gehalte in gras voor een maximale grasopname via een gerichte voederproef