Verkenning sensorgestuurde dosering van loofdodingsmiddelen in pootaardappelen

In 2008 is een verkenning gedaan naar haalbaarheid van sensorgestuurde dosering van loofdodingsmiddelen in pootgoedteelt van aardappelen. Er werd een prototype gebouwd en getest waarmee Finale pleksgewijs gedoseerd werd d.m.v. Greenseeker-sensoren op een klap-spuit-combinatie en een rekenregel die plaatspecifieke meetwaarden doorvertaalde in een minimum effectieve dosering. Ook werden dosis-response proeven uitgevoerd. De eerste resultaten met het prototype en systeem waren positief. Met de sensoren konden variatie in gewasstand in kaart gebracht worden, en deze bleek groter dan verwacht. Bovendien kon de dosering effectief gestuurd worden met de sensormeetwaarden. Het onderzoek laat zien dat reductie in loofdodingsmiddel met sensorsturing mogelijk is. In het onderzoek bleken ras en dosering van Finale geen effect te hebben op verkleuring van navels van knollen. Nader onderzoek aan de beslisregels, validatie in de praktijk inclusief effecten op kwaliteit van de aardappelen is nodig voor implementatie in de praktij

Low‐Temperature Heat Capacities and Thermodynamic Functions of Some Palladium and Platinum Group Chalcogenides. II. Dichalcogenides; PtS2, PtTe2, and PdTe2

Heat capacities of platinum disulfide, platinum ditelluride, and palladium ditelluride were measured in the range 5° to 350°K. They show the normal sigmoidal temperature dependence with no evidence of transitions or other anomalies. The derived heat capacity equations were integrated. Values of Cp, S°—S0°, H°—H0°, and —(F°—H0°)/T are tabulated for selected temperatures. At 298.15°K the entropies are 17.85 cal gfw—1 °K—1 for PtS2, 28.92 cal gfw—1 °K—1 for PtTe2 and 30.25 cal gfw—1 °K—1 for PdTe2. Thermodynamic values have been estimated for other dichalcogenides and related chalcogenides of the platinum group metals.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69847/2/JCPSA6-35-5-1670-1.pd

Size-Dependent Surface Plasmon Dynamics in Metal Nanoparticles

We study the effect of Coulomb correlations on the ultrafast optical dynamics of small metal particles. We demonstrate that a surface-induced dynamical screening of the electron-electron interactions leads to quasiparticle scattering with collective surface excitations. In noble-metal nanoparticles, it results in an interband resonant scattering of d-holes with surface plasmons. We show that this size-dependent many-body effect manifests itself in the differential absorption dynamics for frequencies close to the surface plasmon resonance. In particular, our self-consistent calculations reveal a strong frequency dependence of the relaxation, in agreement with recent femtosecond pump-probe experiments.Comment: 8 pages + 4 figures, final version accepted to PR

Effects of mexiletine and lacosamide on nerve excitability in healthy subjects: a randomized, double-blind, placebo-controlled, crossover study

Selective voltage-gated sodium channel blockers are of growing interest as treatment for pain. For drug development of such compounds, it would be critical to have a biomarker that can be used for proof-of-mechanism. We aimed to evaluate whether drug-induced changes in sodium conductance can be detected in the peripheral nerve excitability profile in 18 healthy subjects. In a randomized, double-blind, 3-way crossover study, effects of single oral doses of 333 mg mexiletine and 300 mg lacosamide were compared with placebo. On each study visit, motor and sensory nerve excitability measurements of the median nerve were performed (predose; and 3 and 6 hours postdose) using Qtrac. Treatment effects were calculated using an analysis of covariance (ANCOVA) with baseline as covariate. Mexiletine and lacosamide had significant effects on multiple motor and sensory nerve excitability variables. Depolarizing threshold electrotonus (TEd40 (40–60 ms)) decreased by mexiletine (estimated difference (ED) −1.37% (95% confidence interval (CI): −2.20, −0.547; P = 0.002) and lacosamide (ED −1.27%, 95% CI: −2.10, −0.443; P = 0.004) in motor nerves. Moreover, mexiletine and lacosamide decreased superexcitability (less negative) in motor nerves (ED 1.74%, 95% CI: 0.615, 2.87; P = 0.004, and ED 1.47%, 95% CI: 0.341, 2.60; P = 0.013, respectively). Strength-duration time constant decreased after lacosamide in motor- (ED −0.0342 ms, 95% CI: −0.0571, −0.0112; P = 0.005) and sensory nerves (ED −0.0778 ms, 95% CI: −0.116, −0.0399; P < 0.001). Mexiletine and lacosamide significantly decrease excitability of motor and sensory nerves, in line with their suggested mechanism of action. Results of this study indicate that nerve excitability threshold tracking can be an effective pharmacodynamic biomarker. The method could be a valuable tool in clinical drug development

Recruitment for a Hospital-Based Pragmatic Clinical Trial using Volunteer Nurses and Students

BACKGROUND/AIMS: Recruitment of subjects is critical to the success of any clinical trial, but achieving this goal can be a challenging endeavor. Volunteer nurse and student enrollers are potentially an important source of recruiters for hospital-based trials; however, little is known of either the efficacy or cost of these types of enrollers. We assessed volunteer clinical nurses and health science students in their rates of enrolling family members in a hospital-based, pragmatic clinical trial of cardiopulmonary resuscitation education, and their ability to achieve target recruitment goals. We hypothesized that students would have a higher enrollment rate and are more cost-effective compared to nurses. METHODS: Volunteer nurses and student enrollers were recruited from eight institutions. Participating nurses were primarily bedside nurses or nurse educators while students were pre-medical, pre-nursing, and pre-health students at local universities. We recorded the frequency of enrollees recruited into the clinical trial by each enroller. Enrollers\u27 impressions of recruitment were assessed using mixed-methods surveys. Cost was estimated based on enrollment data. Overall enrollment data were analyzed using descriptive statistics and generalized estimating equations. RESULTS: From February 2012 to November 2014, 260 hospital personnel (167 nurses and 93 students) enrolled 1493 cardiac patients\u27 family members, achieving target recruitment goals. Of those recruited, 822 (55%) were by nurses, while 671 (45%) were by students. Overall, students enrolled 5.44 (95% confidence interval (CI): 2.88, 10.27) more subjects per month than nurses (p \u3c 0.01). After consenting to participate in recruitment, students had a 2.85 (95% CI: 1.09, 7.43) increased chance of enrolling at least one family member (p = 0.03). Among those who enrolled at least one subject, nurses enrolled a mean of 0.51(95% CI: 0.42, 0.59) subjects monthly, while students enrolled 1.63 (95% CI: 1.37, 1.90) per month (p \u3c 0.01). Of 198 surveyed hospital personnel (127 nurses, 71 students), 168/198 (85%) felt confident conducting enrollment. The variable cost per enrollee recruited was $25.38 per subject for nurses and$23.30 per subject for students. CONCLUSIONS: Overall, volunteer students enrolled more subjects per month at a lower cost than nurses. This work suggests that recruitment goals for a pragmatic clinical trial can be successfully obtained using both nurses and students

Relaxation Dynamics of Photoinduced Changes in the Superfluid Weight of High-Tc Superconductors

In the transient state of d-wave superconductors, we investigate the temporal variation of photoinduced changes in the superfluid weight. We derive the formula that relates the nonlinear response function to the nonequilibrium distribution function. The latter qunatity is obtained by solving the kinetic equation with the electron-electron and the electron-phonon interaction included. By numerical calculations, a nonexponential decay is found at low temperatures in contrast to the usual exponential decay at high temperatures. The nonexponential decay originates from the nonmonotonous temporal variation of the nonequilibrium distribution function at low energies. The main physical process that causes this behavior is not the recombination of quasiparticles as previous phenomenological studies suggested, but the absorption of phonons.Comment: 18 pages, 12 figures; to be published in J. Phys. Soc. Jpn. Vol. 80, No.

Identity of the universal repulsive-core singularity with Yang-Lee edge criticality

Lattice and continuum fluid models with repulsive-core interactions typically display a dominant, critical-type singularity on the real, negative activity axis. Lai and Fisher recently suggested, mainly on numerical grounds, that this repulsive-core singularity is universal and in the same class as the Yang-Lee edge singularities, which arise above criticality at complex activities with positive real part. A general analytic demonstration of this identification is presented here using a field-theory approach with separate representation of the repulsive and attractive parts of the pair interactions.Comment: 6 pages, 3 figure

Video-Only Cardiopulmonary Resuscitation Education for High-Risk Families Before Hospital Discharge: A Multicenter Pragmatic Trial

BACKGROUND: Cardiopulmonary resuscitation (CPR) training rates in the United States are low, highlighting the need to develop CPR educational approaches that are simpler, with broader dissemination potential. The minimum training required to ensure long-term skill retention remains poorly characterized. We compared CPR skill retention among laypersons randomized to training with video-only (VO; no manikin) with those trained with a video self-instruction kit (VSI; with manikin). We hypothesized that VO training would be noninferior to the VSI approach with respect to chest compression (CC) rate. METHODS AND RESULTS: We performed a prospective, cluster randomized trial of CPR education for family members of patients with high-risk cardiac conditions on hospital cardiac units, using a multicenter pragmatic design. Eight hospitals were randomized to offer either VO or VSI training before discharge using volunteer trainers. CPR skills were assessed 6 months post training. Mean CC rate among those trained with VO compared with those trained with VSI was assessed with a noninferiority margin set at 8 CC per min; as a secondary outcome, mean differences in CC depth were assessed. From February 2012 to May 2015, 1464 subjects were enrolled and 522 subjects completed a skills assessment. The mean CC rates were 87.7 (VO) CC per min and 89.3 (VSI) CC per min; we concluded noninferiority for VO based on a mean difference of -1.6 (90% confidence interval, -5.2 to 2.1). The mean CC depth was 40.2 mm (VO) and 45.8 mm (VSI) with a mean difference of -5.6 (95% confidence interval, -7.6 to -3.7). Results were similar after multivariate regression adjustment. CONCLUSIONS: In this large, prospective trial of CPR skill retention, VO training yielded a noninferior difference in CC rate compared with VSI training. CC depth was greater in the VSI group. These findings suggest a potential trade-off in efforts for broad dissemination of basic CPR skills; VO training might allow for greater scalability and dissemination, but with a potential reduction in CC depth. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01514656

Ninth and Tenth Order Virial Coefficients for Hard Spheres in D Dimensions

We evaluate the virial coefficients B_k for k<=10 for hard spheres in dimensions D=2,...,8. Virial coefficients with k even are found to be negative when D>=5. This provides strong evidence that the leading singularity for the virial series lies away from the positive real axis when D>=5. Further analysis provides evidence that negative virial coefficients will be seen for some k>10 for D=4, and there is a distinct possibility that negative virial coefficients will also eventually occur for D=3.Comment: 33 pages, 12 figure