Death after closed adolescent knee injury and popliteal artery occlusion: a case report and clinical review.

A healthy adolescent male soccer player sustained a radiograph-negative, effusion-negative physeal injury of the proximal tibia from a ground-level fall with traumatic occlusion of the popliteal artery. Orthopaedic evaluation and arteriography were delayed for 72 hours after the injury. He arrived at a tertiary referral center in multisystem organ failure secondary to lower extremity ischemic necrosis, septic pulmonary thromboembolism, and systemic shock. Emergent medical evaluation, a high index of suspicion, and a careful neurovascular examination are imperative after every closed knee injury in the young athlete

The Early Promise of TBRI Implementation in Schools

The program known as Trust Based Relational Intervention® (TBRI®) began as an exploration into the detrimental behaviors of foster and adopted children placed in homes with unsuspecting caregivers who assumed their living environment would result in positive results rather than fear based emotions and behaviors. The researchers at the Karyn Purvis Institute of Child Development (KPICD) at Texas Christian University held summer camps for adopted children and through that work developed an intervention to meet the needs of children who had experienced trauma. KPICD identifies these young people as “children from hard places” (Purvis & Cross, 2005). Copeland et al (2007) reported that an estimated 68% of children in the United States have experienced some sort of trauma. This astounding statistic holds great meaning for teachers and administrators, because these children from hard places routinely manifest aggressive and undesired behaviors due to an altering of their physiology. The literature on TBRI® at this point mostly has chronicled success with families, group homes and summer camps (McKenzie, Purvis, & Cross, 2014; Howard, Parris, Neilson, Lusk, Bush, Purvis & Cross, 2014; Purvis & Cross, 2006). TBRI® has only recently been implemented in school settings. This report provides an overview of the impacts of trauma, trauma related work in schools, and the four articles published to this point related to the use of TBRI® in schools

Numerical investigation of high-pressure combustion in rocket engines using Flamelet/Progress-variable models

The present paper deals with the numerical study of high pressure LOx/H2 or LOx/hydrocarbon combustion for propulsion systems. The present research effort is driven by the continued interest in achieving low cost, reliable access to space and more recently, by the renewed interest in hypersonic transportation systems capable of reducing time-to-destination. Moreover, combustion at high pressure has been assumed as a key issue to achieve better propulsive performance and lower environmental impact, as long as the replacement of hydrogen with a hydrocarbon, to reduce the costs related to ground operations and increase flexibility. The current work provides a model for the numerical simulation of high- pressure turbulent combustion employing detailed chemistry description, embedded in a RANS equations solver with a Low Reynolds number k-omega turbulence model. The model used to study such a combustion phenomenon is an extension of the standard flamelet-progress-variable (FPV) turbulent combustion model combined with a Reynolds Averaged Navier-Stokes equation Solver (RANS). In the FPV model, all of the thermo-chemical quantities are evaluated by evolving the mixture fraction Z and a progress variable C. When using a turbulence model in conjunction with FPV model, a probability density function (PDF) is required to evaluate statistical averages of chemical quantities. The choice of such PDF must be a compromise between computational costs and accuracy level. State- of-the-art FPV models are built presuming the functional shape of the joint PDF of Z and C in order to evaluate Favre-averages of thermodynamic quantities. The model here proposed evaluates the most probable joint distribution of Z and C without any assumption on their behavior.Comment: presented at AIAA Scitech 201

Statistical variable selection: an alternative prioritization strategy during the nontarget analysis of LC-HR-MS data

Liquid chromatography coupled to high resolution mass spectrometry (LC-HR-MS) has been one of the main analytical tools for the analysis of small polar organic pollutants in the environment. LC-HR-MS typically produces a large amount of data for a single chromatogram. The analyst is therefore required to perform prioritization prior to nontarget structural elucidation. In the present study, we have combined the F-ratio statistical variable selection and the apex detection algorithms in order to perform prioritization in data sets produced via LC-HR-MS. The approach was validated through the use of semisynthetic data, which was a combination of real environmental data and the artificially added signal of 31 alkanes in that sample. We evaluated the performance of this method as a function of four false detection probabilities, namely: 0.01, 0.02, 0.05, and 0.1%. We generated 100 different semisynthetic data sets for each F-ratio and evaluated that data set using this method. This design of experiment created a population of 30 000 true positives and 32 000 true negatives for each F-ratio, which was considered sufficiently large enough in order to fully validate this method for analysis of LC-HR-MS data. The effect of both the F-ratio and signal-to-noise ratio (S/N) on the performance of the suggested approach were evaluated through normalized statistical tests. We also compared this method to the pixel-by-pixel as well as peak list approaches. More than 92% of features present in the final feature list via the F-ratio method were also present in the conventional peak list generated by MZmine. However, this method was the only approach successful in the classification of samples, and thus prioritization, when compared to the other evaluated approaches. The application potential and limitations of the suggested method are discussed.acceptedVersio

Measurement of CP asymmetry in D 0 → K - K + and D 0 → π - π decays

Time-integrated CP asymmetries in D 0 decays to the final states K - K + and π - π + are measured using proton-proton collisions corresponding to 3fb-1 of integrated luminosity collected at centre-of-mass energies of 7 TeV and 8 TeV. The D 0 mesons are produced in semileptonic b-hadron decays, where the charge of the accompanying muon is used to determine the initial flavour of the charm meson. The difference in CP asymmetries between the two final states is measured to be Δ ACP = ACP (K- K +) ACP (π- π+) = (+ 0.14 ± 0.16 (stat) ± 0.08 (syst)) %. A measurement of A CP (K - K +) is obtained assuming negligible CP violation in charm mixing and in Cabibbo-favoured D decays. It is found to be ACP (K- K+) = (- 0.06 ± 0.15 (stat) ± 0.10 (syst)) %, where the correlation coefficient between ΔA CP and A CP (K - K +) is ρ = 0.28. By combining these results, the CP asymmetry in the D 0 → π - π + channel is A CP (π - π +) = (-0.20 ± 0.19 (stat) ± 0.10 (syst))%

Measurement of the Xi(-)(b) and Omega(-)(b) baryon lifetimes

Using a data sample of pp collisions corresponding to an integrated luminosity of 3 fb−1, the Ξ−b and Ω−b baryons are reconstructed in the Ξ−b → J/ψΞ− and Ω−b → J/ψΩ− decay modes and their lifetimes measured to be τ(Ξ−b) = 1.55+0.10−0.09 (stat) ± 0.03 (syst) ps, τ(Ω−b) = 1.54+0.26−0.21 (stat) ± 0.05 (syst) ps. These are the most precise determinations to date. Both measurements are in good agreement with previous experimental results and with theoretical predictions

Measurement of the resonant and CP components in B¯ 0 → J=ψπþπ− decays

The resonant structure of the reaction B¯0→J/ψπ+π− is studied using data from 3  fb−1 of integrated luminosity collected by the LHCb experiment, one third at 7 TeV center-of-mass energy and the remainder at 8 TeV. The invariant mass of the π+π− pair and three decay angular distributions are used to determine the fractions of the resonant and nonresonant components. Six interfering π+π− states, ρ(770), f0(500), f2(1270), ρ(1450), ω(782) and ρ(1700), are required to give a good description of invariant mass spectra and decay angular distributions. The positive and negative charge parity fractions of each of the resonant final states are determined. The f0(980) meson is not seen and the upper limit on its presence, compared with the observed f0(500) rate, is inconsistent with a model where these scalar mesons are formed from two quarks and two antiquarks (tetraquarks) at the eight standard deviation level. In the qq¯ model, the absolute value of the mixing angle between the f0(980) and the f0(500) scalar mesons is limited to be less than 17° at 90% confidence level

Study of beauty hadron decays into pairs of charm hadrons

First observations of the decays Λb 0 → Λc +D(s) - are reported using data corresponding to an integrated luminosity of 3fb-1 collected at 7 and 8 TeV center-of-mass energies in proton-proton collisions with the LHCb detector. In addition, the most precise measurement of the branching fraction B(Bs 0→D+Ds -) is made and a search is performed for the decays B(s) 0→Λc +Λc -. The results obtained are B(Λb 0→Λc +D-)/ B(Λb 0→Λc +D s -)=0.042±0.003(stat)±0.003(syst), [B(Λb 0→Λc +D s -)/B(B̄0→D+D s -)]/[B(Λb 0→Λ c +π-)/B(B̄0→D +π-)]=0.96±0.02(stat)±0.06(syst),B(B s 0→D+Ds -)/ B(B̄0→D+Ds -)=0. 038±0.004(stat)±0.003(syst),B(B̄0→Λ c +Λc -)/B(B̄ 0→D+Ds -)<0.0022[95%C.L.], B(Bs 0→Λc +Λ c -)/B(Bs 0→D+D s -)<0.30[95%C.L.]. Measurement of the mass of the Λb 0 baryon relative to the B̄0 meson gives M(Λb 0)-M(B̄0)=339. 72±0.24(stat)±0.18(syst)MeV/c2. This result provides the most precise measurement of the mass of the Λb 0 baryon to date