Characterization of a Li-6 loaded liquid organic scintillator for fast neutron spectrometry and thermal neutron detection

The characterization of a liquid scintillator incorporating an aqueous solution of enriched lithium chloride to produce a scintillator with 0.40% Li-6 is presented, including the performance of the scintillator in terms of its optical properties and neutron response. The scintillator was incorporated into a fast neutron spectrometer, and the light output spectra from 2.5 MeV, 14.1 MeV, and Cf-252 neutrons were measured using capture-gated coincidence techniques. The spectrometer was operated without coincidence to perform thermal neutron measurements. Possible improvements in spectrometer performance are discussed.Comment: Submitted to Applied Radiation and Isotopes. 11 pages, 7 figures, 3 tables. Revision addresses reviewers' comment

Understanding the process of psychological development in youth athletes attending an intensive wrestling camp

This study used a grounded theory methodology to understand if and how psychological development in youth athletes was facilitated by an ‘intensive’ summer wrestling camp experience. The theoretical sampling approach involved 10 athlete participants of the camp, nine parents of athletes, the director of the camp, and four camp staff members, who took part in a series of interviews before, during, and after the camp. Two researchers were also embedded in the camp and attended all sessions, took detailed notes, collected camp materials, and conducted observations. Following a grounded theory analysis approach, a model is presented that outlines how youth participants’ developed psychological qualities from the coach created hallenges and adversity that were systematically designed to facilitate sport performance enhancement and life skills. Variations emerged in psychological antecedents and characteristics, how the challenging wrestling camp environment was interpreted and experienced, and how learning was transferred to sport and life domains outside of the wrestling camp. This study provided insight into a unique youth sport context that was able to simultaneously develop psychological qualities to be used as sport performance enhancement and life skills

Results of the BiPo-1 prototype for radiopurity measurements for the SuperNEMO double beta decay source foils

The development of BiPo detectors is dedicated to the measurement of extremely high radiopurity in $^{208}$Tl and $^{214}$Bi for the SuperNEMO double beta decay source foils. A modular prototype, called BiPo-1, with 0.8 $m^2$ of sensitive surface area, has been running in the Modane Underground Laboratory since February, 2008. The goal of BiPo-1 is to measure the different components of the background and in particular the surface radiopurity of the plastic scintillators that make up the detector. The first phase of data collection has been dedicated to the measurement of the radiopurity in $^{208}$Tl. After more than one year of background measurement, a surface activity of the scintillators of $\mathcal{A}$($^{208}$Tl) $=$ 1.5 $\mu$Bq/m$^2$ is reported here. Given this level of background, a larger BiPo detector having 12 m$^2$ of active surface area, is able to qualify the radiopurity of the SuperNEMO selenium double beta decay foils with the required sensitivity of $\mathcal{A}$($^{208}$Tl) $<$ 2 $\mu$Bq/kg (90% C.L.) with a six month measurement.Comment: 24 pages, submitted to N.I.M.

Provenance variation in Pinus caribaea, P. oocarpa and P. patula ssp. Tecunumanii

An international study of provenance variation in Pinus caribaea Morelet and P. oocarpa Schiede in Central America and the Caribbean started in the early 1960s. By the early 1970s seed had been distributed to over fifty countries for many hundreds of trials. By the late 1970s the most comprehensive of these had reached seven years, the optimum age for evaluation. A coordinated assessment programme was undertaken in a set of 29 trials in which 25 P. caribaea and 20 P. oocarpa provenances were represented. Four of the P. oocarpa sources were later recognized as P. patula Schiede &amp; Deppe ssp. tecunumanii (Equiluz &amp; Perry) Styles. Provenance representation was comprehensive for P. caribaea vars. hondurensis Barr. &amp; Golf. and caribaea, except for the omission of a few isolated populations; only one var. bahamensis Barr. &amp; Golf. provenance was included. Representation was satisfactory for P. oocarpa in Central America, but none of the populations in the central part of the range of P. patula ssp. tecunumanii in Honduras and Guatemala was sampled. New international trials of both P. caribaea var. bahamensis and P. patula ssp. tecunumanii are now in progress. Overall test site coverage was good except for P. caribaea vars. bahamensis and caribaea. Eighteen traits were assessed to describe productivity, stem quality, branching, reproduction, wood density and oleoresin composition. These are summarized in provenance-locality tables. Analysis of the data revealed statistically and operationally significant general differences between provenance regions for all three species as well as local differences between provenances within the regions. Five major groups emerged in P. caribaea, viz. var. caribaea, var. bahamensis, and inland, coastal and insular var. hondurensis. Each had productivity and silvicultural attributes that were in themselves of sufficient economic importance to influence choice for operational use in different sets of circumstances. Four provenance regions could be distinguished for P. oocarpa, the Mexican, North Guatemalan, South Guatemalan and Honduras-Nicaraguan. The Mexican type had poor productivity and undesirable silvicultural features but the differences between the other three were in traits that had little or no immediate operational significance. The four P. patula ssp. tecunumanii provenances separated on branching traits and resin composition into a group of the three Nicaraguan populations and the one from Belize. Although geno type environment interaction effects were not statistically estimated here, there were indications that they exist at the provenance region level for the three varieties of P. caribaea particularly where wind and biotic effects are significant factors in the environment. These trials have provided data that can be utilized not only to make immediate operation-al gains through provenance selection, but also to plan breeding strategies to enhance populations and to create synthetic varieties in a systematic genetic development for each species.</p

Provenance variation in Pinus caribaea, P. oocarpa and P. patula ssp. Tecunumanii

An international study of provenance variation in Pinus caribaea Morelet and P. oocarpa Schiede in Central America and the Caribbean started in the early 1960s. By the early 1970s seed had been distributed to over fifty countries for many hundreds of trials. By the late 1970s the most comprehensive of these had reached seven years, the optimum age for evaluation. A coordinated assessment programme was undertaken in a set of 29 trials in which 25 P. caribaea and 20 P. oocarpa provenances were represented. Four of the P. oocarpa sources were later recognized as P. patula Schiede andamp; Deppe ssp. tecunumanii (Equiluz andamp; Perry) Styles. Provenance representation was comprehensive for P. caribaea vars. hondurensis Barr. andamp; Golf. and caribaea, except for the omission of a few isolated populations; only one var. bahamensis Barr. andamp; Golf. provenance was included. Representation was satisfactory for P. oocarpa in Central America, but none of the populations in the central part of the range of P. patula ssp. tecunumanii in Honduras and Guatemala was sampled. New international trials of both P. caribaea var. bahamensis and P. patula ssp. tecunumanii are now in progress. Overall test site coverage was good except for P. caribaea vars. bahamensis and caribaea. Eighteen traits were assessed to describe productivity, stem quality, branching, reproduction, wood density and oleoresin composition. These are summarized in provenance-locality tables. Analysis of the data revealed statistically and operationally significant general differences between provenance regions for all three species as well as local differences between provenances within the regions. Five major groups emerged in P. caribaea, viz. var. caribaea, var. bahamensis, and inland, coastal and insular var. hondurensis. Each had productivity and silvicultural attributes that were in themselves of sufficient economic importance to influence choice for operational use in different sets of circumstances. Four provenance regions could be distinguished for P. oocarpa, the Mexican, North Guatemalan, South Guatemalan and Honduras-Nicaraguan. The Mexican type had poor productivity and undesirable silvicultural features but the differences between the other three were in traits that had little or no immediate operational significance. The four P. patula ssp. tecunumanii provenances separated on branching traits and resin composition into a group of the three Nicaraguan populations and the one from Belize. Although geno type environment interaction effects were not statistically estimated here, there were indications that they exist at the provenance region level for the three varieties of P. caribaea particularly where wind and biotic effects are significant factors in the environment. These trials have provided data that can be utilized not only to make immediate operation-al gains through provenance selection, but also to plan breeding strategies to enhance populations and to create synthetic varieties in a systematic genetic development for each species.</p

Recovery of cardiac function in cardiomyopathy caused by titin truncation

10.1001/jamacardio.2016.0208JAMA Cardiology12234-23