Rare Kaon Decays

The current status of rare kaon decay experiments is reviewed. New limits in the search for Lepton Flavor Violation are discussed, as are new measurements of the CKM matrix.Comment: 8 pages, 3 figures, LaTeX, presented at the 3rd International Conference on B Phyiscs and CP Violation, Taipei December 3-7, 199

A Data-Driven Methodology to Comprehensively Assess Bone Drilling Using Radar Plots

BACKGROUND: The study aims to develop a data-driven methodology to assess bone drilling in preparation for future clinical trials in residency training. The existing assessment methods are either subjective or do not consider the interdependence among individual skill factors, such as time and accuracy. This study uses quantitative data and radar plots to visualize the balance of the selected skill factors. METHODS: In the experiment, straight vertical drilling was assessed across 3 skill levels: expert surgeons (N = 10), intermediate residents (postgraduate year-2-5, N = 5), and novice residents (postgraduate year-1, N = 10). Motion and force were measured for each drilling trial, and data from multiple trials were then converted into 5 performance indicators, including overshoot, drilling time, overshoot consistency, time consistency, and force fluctuation. Each indicator was then scored between 0 and 10, with 10 being the best, and plotted into a radar plot. RESULTS: Statistical difference (p \u3c 0.05) was confirmed among 3 skill levels in force, time, and overshoot data. The radar plots revealed that the novice group exhibited the most distorted pentagons compared with the well-formed pentagons observed in the case of expert participants. The intermediate group showed slight distortion that was between the expert and novice groups. CONCLUSION/CLINICAL RELEVANCE: This research shows the utility of radar plots in drilling assessment in a comprehensive manner and lays the groundwork for a data-driven training scheme to prepare novice residents for clinical practice

Kaon decays and the flavour problem

After a brief introduction to the so-called flavour problem, we discuss the role of rare K decays in probing the mechanism of quark-flavour mixing. Particular attention is devoted to the formulation of the Minimal Flavour Violation hypothesis, as a general and natural solution to the flavour problem, and to the fundamental role of K -> pi nu nu-bar decays in testing this scenario.Comment: 10 pages, 6 figures, contribution to TH 2002 (Paris, July 2002

Is it still worth searching for lepton flavor violation in rare kaon decays?

Prospective searches for lepton flavor violation (LFV) in rare kaon decays at the existing and future intermediate-energy accelerators are considered. The proposed studies are complementary to LFV searches in muon-decay experiments and offer a unique opportunity to probe models with approximately conserved fermion-generation quantum number with sensitivity superior to that in other processes. Consequently, new searches for LFV in kaon decays are an important and independent part of the general program of searches for lepton flavor violation in the final states with charged leptons.Comment: 30 pages, 10 figures. An extended version of the talk given at the Chicago Flavor Seminar, February 27, 2004. In the new version some misprints were corrected and some new data for LFV-processes were added. The main content of the paper was not changed. The paper is published in Yad. Fiz. 68, 1272 (2005

The opportunities and challenges to co-designing policy options for tree health with policy makers, researchers and land managers

\ua9 2023. We describe experiences between 2018 and 2021 co-designing tree health policy options linked with the UK\u27s evolving land use policy post EU-Exit within the Future Farming and Countryside Programme. Policy makers, researchers and more than 250 land managers took part in a series of co-design engagements in a three-phase iterative co-design process that culminated in a new Tree Health Pilot. After defining the components of co-design, we describe how relationships between policy makers, researchers and land managers were built, the methods researchers introduced into the process to build capability and support participation, and the outcomes in terms of the key opportunities and challenges for policy co-design. We conclude that it is possible to move policy design beyond user focused research and into co-design. However, this relies on adequate time and resources required to build trust and fully engage all parties in a meaningful way, including the development of tools and techniques that include experimentation, different knowledge types, and moving from research and evidence collection into design. Having policy makers with participatory mindsets in the same space as land managers was important to facilitating active learning between all of those involved in the collective. Researchers played a critical role in the co-design, balancing the views and understandings of the policy community with those of the land manager community, facilitating learning, and selecting tools and techniques to make design options explicit. We conclude that policy co-design in the land-based and environmental sector is a real opportunity at an early stage of realisation, but the effectiveness and range of positive and negative outcomes and impacts will need to be evaluated in the future

Response of selected plant and insect species to simulated solid rocket exhaust mixtures and to exhaust components from solid rocket fuels

The effects of solid rocket fuel (SRF) exhaust on selected plant and and insect species in the Merritt Island, Florida area was investigated in order to determine if the exhaust clouds generated by shuttle launches would adversely affect the native, plants of the Merritt Island Wildlife Refuge, the citrus production, or the beekeeping industry of the island. Conditions were simulated in greenhouse exposure chambers and field chambers constructed to model the ideal continuous stirred tank reactor. A plant exposure system was developed for dispensing and monitoring the two major chemicals in SRF exhaust, HCl and Al203, and for dispensing and monitoring SRF exhaust (controlled fuel burns). Plants native to Merritt Island, Florida were grown and used as test species. Dose-response relationships were determined for short term exposure of selected plant species to HCl, Al203, and mixtures of the two to SRF exhaust

Measuring the quantum efficiency of single radiating dipoles using a scanning mirror

Using scanning probe techniques, we show the controlled manipulation of the radiation from single dipoles. In one experiment we study the modification of the fluorescence lifetime of a single molecular dipole in front of a movable silver mirror. A second experiment demonstrates the changing plasmon spectrum of a gold nanoparticle in front of a dielectric mirror. Comparison of our data with theoretical models allows determination of the quantum efficiency of each radiating dipole.Comment: 4 pages, 4 figure

Subnanosecond spectral diffusion measurement using photon correlation

Spectral diffusion is a result of random spectral jumps of a narrow line as a result of a fluctuating environment. It is an important issue in spectroscopy, because the observed spectral broadening prevents access to the intrinsic line properties. However, its characteristic parameters provide local information on the environment of a light emitter embedded in a solid matrix, or moving within a fluid, leading to numerous applications in physics and biology. We present a new experimental technique for measuring spectral diffusion based on photon correlations within a spectral line. Autocorrelation on half of the line and cross-correlation between the two halves give a quantitative value of the spectral diffusion time, with a resolution only limited by the correlation set-up. We have measured spectral diffusion of the photoluminescence of a single light emitter with a time resolution of 90 ps, exceeding by four orders of magnitude the best resolution reported to date

Rapid consumption of phytoplankton and ice algae by Arctic soft-sediment benthic communities: Evidence using natural and 13C-labeled food materials

Reduction of sea ice in the Arctic may significantly alter the relative fluxes of phytoplankton and ice algae to the seafloor. To examine the response of Arctic benthic communities to changing food supplies, we incubated sediment cores collected from two sites (Smeerenburg Fjord, northwest Svalbard in May 2003 and Storfjord Trench, Barents Sea in May 2004) with controlled additions of natural phytoplankton and ice algal assemblages, and laboratory-cultured 13C-labeled ice algae (Nitzschia frigida, in 2004 only). We measured sediment respiration, pigments, lipid biomarkers, and compound-specific δ13C signals over the course of incubations. Both communities responded rapidly to the addition of food materials: regardless of food type, concentrations of organic biomarkers (pigments and fatty acids) decreased to the levels of control cores within seven days. Although we found no evidence for selective ingestion of the different food types by macrofauna, fatty acids were differentially consumed. The enriched polyunsaturated fatty acids of the ice algae were preferentially utilized compared to saturated and monounsaturated fatty acids bound in ice algae. However, the saturated and monounsaturated fatty acids of phytoplankton (with depleted polyunsaturated fatty acids) are utilized more efficiently than those counterparts bound in ice algae. Bacterial activity was stimulated by food addition, indicated by the immediate increase of bacteria-specific fatty acids, but the direct assimilation of 13C-labeled carbon into bacterial biomass was limited. Our results imply that Arctic benthic communities can meet their energetic requirements by altering strategies to assimilate different components from variable food supplies