1,290 research outputs found

    The Value of Transcranial Doppler in Predicting Cerebral Ischaemia During Carotid Endarterectomy

    Get PDF
    AbstractObjectives: transcranial Doppler (TCD) measurement of middle cerebral artery velocity (MCAV) is an indirect method of assessing cerebral blood flow and therefore predicting patients at risk of stroke during carotid endarterectomy (CEA), and may be used to determine the need for shunting. This study evaluates the accuracy of three accepted TCD criteria in predicting the need for a shunt. Design: prospective study. Methods: one hundred and twenty consecutive CEA were performed under loco/regional anaesthesia. Patients monitored by TCD and Awake neurological examination were included. Shunts were inserted if there was neurological deterioration. Awake patient monitoring was compared with the three TCD criteria. Results: inadequate TCD recordings were obtained in 16 operations (13%). In the remainder (104 cases), 12 developed symptoms of cerebral ischaemia and required a shunt (12%). Comparisons with the three accepted criteria were as follows: (1) m MCAV <30 cm/s had a sensitivity, specificity, PPV and NPV of 92%, 49%, 19%, and 98%, respectively; (2) clamp/pre-clamp ratio <0.6 had a sensitivity, specificity, PPV and NPV of 92%, 75%, 33% and 99%, respectively; (3) greater than 50% reduction in m MCAV had a sensitivity, specificity, PPV and NPV valves of 83%, 77%, 32% and 97%, respectively. Conclusions: TCD flow velocities are not a reliable method for detecting cerebral ischaemia and therefore determining the need for a shunt in CEA

    Lockin to Weak Ferromagnetism in TbNi2B2C and ErNi2B2C

    Full text link
    This article describes a model in which ferromagnetism necessarily accompanies a spin-density-wave lockin transition in the borocarbide structure provided the commensurate phase wave vector satisfies Q = (m/n)a* with m even and n odd. The results account for the magnetic properties of TbNi2B2C, and are also possibly relevant also for those of ErNi2B2C.Comment: 4 page

    Ki-67 (30-9) scoring and differentiation of Luminal A- and Luminal B-like breast cancer subtypes

    Get PDF
    INTRODUCTION: Ki-67 labeling index assessed by immunohistochemical assays has been shown useful in assessing the risk of recurrence for estrogen receptor (ER)-positive HER2-negative breast cancers (BC) and distinguishing Luminal A-like from Luminal B-like tumors. We aimed to assess the performance of the Ventana CONFIRM anti-Ki-67 (30-9) Rabbit Monoclonal Primary Antibody. METHODS: We constructed a case-cohort design based on a random sample (n\u2009=\u2009679) of all patients operated on for a first primary, non-metastatic, ER-positive, HER2-negative BC at the European Institute of Oncology (IEO) Milan, Italy during 1998-2002 and all additional patients (n\u2009=\u2009303) operated during the same period, who developed an event (metastasis in distant organs or death due to BC as primary event) and were not included in the previous subset. Multivariable Cox proportional hazards regression with inverse subcohort sampling probability weighting was used to evaluate the risk of event according to Ki-67 (30-9) and derived intrinsic molecular subtype, using previously defined cutoff values, i.e., respectively 14% and 20%. RESULTS: Ki-67 was\u2009&lt;\u200914% in 318 patients (32.4%), comprised between 14 and 19% in 245 patients (24.9%) and\u2009 65\u200920 in 419 patients (42.7%). At multivariable analysis, the risk of developing distant disease was 1.88 (95% CI 1.20-2.93; P\u2009=\u20090.006) for those with Ki-67 comprised between 14 and 19%, and 3.06 (95% CI 1.93-4.84; P\u2009&lt;\u20090.0001) for those with Ki-67\u2009 65\u200920% compared to those with Ki-67\u2009&lt;\u200914%. Patients with Luminal B-like BC had an approximate twofold risk of developing distant disease (HR\u2009=\u20091.91; 95% CI 1.35-2.71; P\u2009=\u20090.0003) than patients with Luminal A-like BC defined using Ki-67 (30-9). CONCLUSIONS: Ki-67 evaluation using the 30-9 rabbit monoclonal primary antibody was able to stratify patients with ER-positive HER2-negative BC into prognostically distinct groups. Ki-67 assessment, with strict adherence to the international recommendations, should be included among the clinically useful biological parameters for the best treatment of patients with BC

    A Composite Little Higgs Model

    Full text link
    We describe a natural UV complete theory with a composite little Higgs. Below a TeV we have the minimal Standard Model with a light Higgs, and an extra neutral scalar. At the TeV scale there are additional scalars, gauge bosons, and vector-like charge 2/3 quarks, whose couplings to the Higgs greatly reduce the UV sensitivity of the Higgs potential. Stabilization of the Higgs mass squared parameter, without finetuning, occurs due to a softly broken shift symmetry--the Higgs is a pseudo Nambu-Goldstone boson. Above the 10 TeV scale the theory has new strongly coupled interactions. A perturbatively renormalizable UV completion, with softly broken supersymmetry at 10 TeV is explicitly worked out. Our theory contains new particles which are odd under an exact "dark matter parity", (-1)^{(2S+3B+L)}. We argue that such a parity is likely to be a feature of many theories of new TeV scale physics. The lightest parity odd particle, or "LPOP", is most likely a neutral fermion, and may make a good dark matter candidate, with similar experimental signatures to the neutralino of the MSSM. We give a general effective field theory analysis of the calculation of corrections to precision electroweak observables.Comment: 28 page

    A Minimal Superstring Standard Model II: A Phenomenological Study

    Full text link
    Recently, we demonstrated the existence of heterotic--string solutions in which the observable sector effective field theory just below the string scale reduces to that of the MSSM, with the standard observable gauge group being just SU(3)_C x SU(2)_L x U(1)_Y and the SU(3)_C x SU(2)_L x U(1)_Y-charged spectrum of the observable sector consisting solely of the MSSM spectrum. Associated with this model is a set of distinct flat directions of vacuum expectation values (VEVs) of non-Abelian singlet fields that all produce solely the MSSM spectrum. In this paper, we study the effective superpotential induced by these choices of flat directions. We investigate whether sufficient degrees of freedom exist in these singlet flat directions to satisfy various phenomenological constraints imposed by the observed Standard Model data. For each flat direction, the effective superpotential is given to sixth order. The variations in the singlet and hidden sector low energy spectrums are analyzed. We then determine the mass matrices (to all finite orders) for the three generations of MSSM quarks and leptons. Possible Higgs mu-terms are investigated. We conclude by considering generalizations of our flat directions involving VEVs of non-Abelian fields.Comment: 41 pages. Standard Late

    Pathways into services for offenders with intellectual disabilities : childhood experience, diagnostic information and offence variables

    Get PDF
    The patterns and pathways into intellectual disability (ID) offender services were studied through case file review for 477 participants referred in one calendar year to community generic, community forensic, and low, medium, and maximum secure services. Data were gathered on referral source, demographic information, index behavior, prior problem behaviors, diagnostic information, and abuse or deprivation. Community referrers tended to refer to community services and secure service referrers to secure services. Physical and verbal violence were the most frequent index behaviors, whereas contact sexual offenses were more prominent in maximum security. Age at first incident varied with security, with the youngest in maximum secure services. Attention-deficit/hyperactivity disorder or conduct disorder was the most frequently recorded diagnosis, and severe deprivation was the most frequent adverse developmental experience. Fire starting, theft, and road traffic offenses did not feature prominently. Generic community services accepted a number of referrals with forensic-type behavior and had higher proportions of both women and people with moderate or severe ID

    K-Pi=6+ and 8- isomer decays in HF-172 and DELTA-K=8 E1 transition rates

    Get PDF
    A recoil-shadow measurement of isomer decay in 172Hf has revealed many weak gamma-ray transitions. One of these is a sevenfold K-forbidden E1 transition from the K(pi) = 8- isomer (T1/2 = 163 ns) to the K(pi) = 0+ ground-state band. The low hindrance factor for this transition in Hf-172 is compared with the hindrance factors for other DELTAK = 8 E1 transitions

    Resolution of the w-179-isomer anomaly: exposure of a Fermi-aligned s-band

    Get PDF
    The K-pi = 35-/2, five-quasiparticle isomer in W-179 is shown to decay into the region of a backbend in the 7-/2[514] band, allowing for the first time the identification of a full set of aligned-band states. Destructive interference results from level mixing in the band-crossing region. The deduced gamma-ray branching ratios are used to establish the mixing matrix elements and to show that the aligned band has a high value of the K quantum number. The properties of well-defined alignment and yet also high K provide the first clear example of a Fermi-aligned s band. The anomalous decay of the isomer itself is now explained

    Phenomenology of Non-Abelian Flat Directions in a Minimal Superstring Standard Model

    Get PDF
    Recently, we presented the first non-Abelian flat directions that produce from a heterotic string model solely the three-generation MSSM states as the massless spectrum in the observable sector of the low energy effective field theory. In this paper we continue to develop the systematic techniques for the analysis of nonrenormalizable superpotential terms and non-Abelian flat direction in realistic string models. Some of our non-Abelian directions were F-flat to all finite orders in the superpotential. We study for the same string model the varying phenomenologies resulting from a large set of such all-order flat directions. We focus on the quark, charged lepton, and Higgs doublet mass matrices resulting for our phenomenologically superior non-Abelian flat direction. We review and apply a string-related method for generating large mass hierarchies between MSSM generations, first discussed in string-derived flipped SU(5) models, when all generational mass terms are of renormalizable or very low non-renormalizable order

    The structure and dynamics of young star clusters: King 16, NGC 1931, NGC 637 and NGC 189

    Full text link
    In this paper, using 2MASS photometry, we study the structural and dynamical properties of four young star clusters viz. King 16, NGC 1931, NGC 637 and NGC 189. For the clusters King 16, NGC 1931, NGC 637 and NGC 189, we obtain the limiting radii of 7', 12', 6' and 5' which correspond to linear radii of 3.6 pc, 8.85 pc, 3.96 pc and 2.8 pc respectively. The reddening values E(BV)E(B-V) obtained for the clusters are 0.85, 0.65--0.85, 0.6 and 0.53 and their true distances are 1786 pc, 3062 pc, 2270 pc and 912 pc respectively. Ages of the clusters are 6 Myr, 4 Myr, 4 Myr and 10 Myr respectively. We compare their structures, luminosity functions and mass functions (ϕ(M)=dN/dMM(1+χ)\phi(M) = dN/dM \propto M^{-(1+\chi)}) to the parameter τ=tage/trelax\tau = t_{age}/t_{relax} to study the star formation process and the dynamical evolution of these clusters. We find that, for our sample, mass seggregation is observed in clusters or their cores only when the ages of the clusters are comparable to their relaxation times (τ1\tau \geq 1). These results suggest mass seggregation due to dynamical effects. The values of χ\chi, which characterise the overall mass functions for the clusters are 0.96 ±\pm 0.11, 1.16 ±\pm 0.18, 0.55 ±\pm 0.14 and 0.66 ±\pm 0.31 respectively. The change in χ\chi as a function of radius is a good indicator of the dynamical state of clusters.Comment: Accepted for publication in Astrophysics & Space Scienc
    corecore