Rotational elasticity and couplings to linear elasticity

It is the aim of the paper to present a new point of view on rotational elasticity in a nonlinear setting using orthogonal matrices. The proposed model, in the linear approximation, can be compared to the well known equilibrium equations of static linear elasticity. An appropriate kinetic energy is identified and we present a dynamical model of rotational elasticity. The propagation of elastic waves in such a medium is studied and we find two classes of waves, transversal rotational waves and longitudinal rotational waves, both of which are solutions of the nonlinear partial differential equations. For certain parameter choices, the transversal wave velocity can be greater than the longitudinal wave velocity. Moreover, parameter ranges are identified where the model describes an auxetic material. However, in all cases the potential energy functional is positive definite. Finally, we couple the rotational waves to linear elastic waves to study the behaviour of the coupled system. We find wave like solutions to the coupled equations and can visualise our results with the help of suitable figures.Comment: 19 pages, 2 figures, heavily revised and largely extended versio

Bilateral Assessment of Functional Tasks for Robot-assisted Therapy Applications

This article presents a novel evaluation system along with methods to evaluate bilateral coordination of arm function on activities of daily living tasks before and after robot-assisted therapy. An affordable bilateral assessment system (BiAS) consisting of two mini-passive measuring units modeled as three degree of freedom robots is described. The process for evaluating functional tasks using the BiAS is presented and we demonstrate its ability to measure wrist kinematic trajectories. Three metrics, phase difference, movement overlap, and task completion time, are used to evaluate the BiAS system on a bilateral symmetric (bi-drink) and a bilateral asymmetric (bi-pour) functional task. Wrist position and velocity trajectories are evaluated using these metrics to provide insight into temporal and spatial bilateral deficits after stroke. The BiAS system quantified movements of the wrists during functional tasks and detected differences in impaired and unimpaired arm movements. Case studies showed that stroke patients compared to healthy subjects move slower and are less likely to use their arm simultaneously even when the functional task requires simultaneous movement. After robot-assisted therapy, interlimb coordination spatial deficits moved toward normal coordination on functional tasks

RNAseq Analyses Identify Tumor Necrosis Factor-Mediated Inflammation as a Major Abnormality in ALS Spinal Cord

ALS is a rapidly progressive, devastating neurodegenerative illness of adults that produces disabling weakness and spasticity arising from death of lower and upper motor neurons. No meaningful therapies exist to slow ALS progression, and molecular insights into pathogenesis and progression are sorely needed. In that context, we used high-depth, next generation RNA sequencing (RNAseq, Illumina) to define gene network abnormalities in RNA samples depleted of rRNA and isolated from cervical spinal cord sections of 7 ALS and 8 CTL samples. We aligned \u3e50 million 2X150 bp paired-end sequences/sample to the hg19 human genome and applied three different algorithms (Cuffdiff2, DEseq2, EdgeR) for identification of differentially expressed genes (DEG’s). Ingenuity Pathways Analysis (IPA) and Weighted Gene Co-expression Network Analysis (WGCNA) identified inflammatory processes as significantly elevated in our ALS samples, with tumor necrosis factor (TNF) found to be a major pathway regulator (IPA) and TNFα-induced protein 2 (TNFAIP2) as a major network “hub” gene (WGCNA). Using the oPOSSUM algorithm, we analyzed transcription factors (TF) controlling expression of the nine DEG/hub genes in the ALS samples and identified TF’s involved in inflammation (NFkB, REL, NFkB1) and macrophage function (NR1H2::RXRA heterodimer). Transient expression in human iPSC-derived motor neurons of TNFAIP2 (also a DEG identified by all three algorithms) reduced cell viability and induced caspase 3/7 activation. Using high-density RNAseq, multiple algorithms for DEG identification, and an unsupervised gene co-expression network approach, we identified significant elevation of inflammatory processes in ALS spinal cord with TNF as a major regulatory molecule. Overexpression of the DEG TNFAIP2 in human motor neurons, the population most vulnerable to die in ALS, increased cell death and caspase 3/7 activation. We propose that therapies targeted to reduce inflammatory TNFα signaling may be helpful in ALS patients

An investigation into the validity of cervical spine motion palpation using subjects with congenital block vertebrae as a 'gold standard'

BACKGROUND: Although the effectiveness of manipulative therapy for treating back and neck pain has been demonstrated, the validity of many of the procedures used to detect joint dysfunction has not been confirmed. Practitioners of manual medicine frequently employ motion palpation as a diagnostic tool, despite conflicting evidence regarding its utility and reliability. The introduction of various spinal models with artificially introduced 'fixations' as an attempt to introduce a 'gold standard' has met with frustration and frequent mechanical failure. Because direct comparison against a 'gold standard' allows the validity, specificity and sensitivity of a test to be calculated, the identification of a realistic 'gold standard' against which motion palpation can be evaluated is essential. The objective of this study was to introduce a new, realistic, 'gold standard', the congenital block vertebra (CBV) to assess the validity of motion palpation in detecting a true fixation. METHODS: Twenty fourth year chiropractic students examined the cervical spines of three subjects with single level congenital block vertebrae, using two commonly employed motion palpation tests. The examiners, who were blinded to the presence of congenital block vertebrae, were asked to identify the most hypomobile segment(s). The congenital block segments included two subjects with fusion at the C2–3 level and one with fusion at C5-6. Exclusion criteria included subjects who were frankly symptomatic, had moderate or severe degenerative changes in their cervical spines, or displayed signs of cervical instability. Spinal levels were marked on the subject's skin overlying the facet joints from C1 to C7 bilaterally and the motion segments were then marked alphabetically with 'A' corresponding to C1-2. Kappa coefficients (K) were calculated to determine the validity of motion palpation to detect the congenitally fused segments as the 'most hypomobile' segments. Sensitivity and specificity of the diagnostic procedure were also calculated. RESULTS: Kappa coefficients (K) showed substantial overall agreement for identification of the segment of greatest hypomobility (K = 0.65), with substantial (K = 0.76) and moderate (K = 0.46) agreement for hypomobility at C2-3 and C5-6 respectively. Sensitivity ranged from 55% at the C5-6 CBV to 78% at the C2-3 level. Specificity of the procedure was high (91 – 98%). CONCLUSION: This study indicates that relatively inexperienced examiners are capable of correctly identifying inter-segmental fixations (CBV) in the cervical spine using 2 commonly employed motion palpation tests. The use of a 'gold standard' (CBV) in this study and the substantial agreement achieved lends support to the validity of motion palpation in detecting major spinal fixations in the cervical spine

Nitroxyl (HNO) Stimulates Soluble Guanylyl Cyclase to Suppress Cardiomyocyte Hypertrophy and Superoxide Generation

Background: New therapeutic targets for cardiac hypertrophy, an independent risk factor for heart failure and death, are essential. HNO is a novel redox sibling of NON attracting considerable attention for the treatment of cardiovascular disorders, eliciting cGMP-dependent vasodilatation yet cGMP-independent positive inotropy. The impact of HNO on cardiac hypertrophy (which is negatively regulated by cGMP) however has not been investigated. Methods: Neonatal rat cardiomyocytes were incubated with angiotensin II (Ang II) in the presence and absence of the HNO donor Angeli’s salt (sodium trioxodinitrate) or B-type natriuretic peptide, BNP (all 1 mmol/L). Hypertrophic responses and its triggers, as well as cGMP signaling, were determined. Results: We now demonstrate that Angeli’s salt inhibits Ang II-induced hypertrophic responses in cardiomyocytes, including increases in cardiomyocyte size, de novo protein synthesis and b-myosin heavy chain expression. Angeli’s salt also suppresses Ang II induction of key triggers of the cardiomyocyte hypertrophic response, including NADPH oxidase (on both Nox2 expression and superoxide generation), as well as p38 mitogen-activated protein kinase (p38MAPK). The antihypertrophic, superoxide-suppressing and cGMP-elevating effects of Angeli’s salt were mimicked by BNP. We also demonstrate that the effects of Angeli’s salt are specifically mediated by HNO (with no role for NON or nitrite), with subsequent activation of cardiomyocyte soluble guanylyl cyclase (sGC) and cGMP signaling (on both cGMP-dependen

American Society of Clinical Oncology/College ofAmerican Pathologists guideline recommendations forimmunohistochemical testing of estrogen andprogesterone receptors in breast cancer

Purpose: To develop a guideline to improve theaccuracy of immunohistochemical (IHC) estrogen receptor(ER) and progesterone receptor (PgR) testing in breastcancer and the utility of these receptors as predictivemarkers.Methods: The American Society of Clinical Oncologyand the College of American Pathologists convened aninternational Expert Panel that conducted a systematicreview and evaluation of the literature in partnership withCancer Care Ontario and developed recommendations foroptimal IHC ER/PgR testing performance.Results: Up to 20% of current IHC determinations ofER and PgR testing worldwide may be inaccurate (falsenegative or false positive). Most of the issues with testinghave occurred because of variation in preanalyticvariables, thresholds for positivity, and interpretationcriteria.Recommendations: The Panel recommends that ER andPgR status be determined on all invasive breast cancers andbreast cancer recurrences. A testing algorithm that relieson accurate, reproducible assay performance is proposed.Elements to reliably reduce assay variation are specified. It is recommended that ER and PgR assays be consideredpositive if there are at least 1% positive tumor nuclei in the sample on testing in the presence of expected reactivity of internal (normal epithelial elements) and external controls. The absence of benefit from endocrine therapy for women with ER-negative invasive breast cancers has been confirmed in large overviews of randomized clinical trials.(Arch Pathol Lab Med. 2010;134:907–922

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal