Regulation of peripheral vascular tone in patients with heart failure:Contribution of angiotensin II

Objective—To determine directly the contribution of angiotensin II to basal and sympathetically stimulated peripheral arteriolar tone in patients with heart failure.
Design—Parallel group comparison.
Subjects—Nine patients with New York Heart Association grade II-IV chronic heart failure, and age and sex matched controls.
Interventions—Forearm plethysmography, lower body negative pressure, local intra-arterial administration of losartan, angiotensin II, and noradrenaline, and estimation of plasma hormone concentrations.
Main outcome measures—Forearm blood flow responses, plasma hormone concentrations.
Results—Baseline blood pressure, heart rate, and forearm blood flow did not differ between patients and controls. In comparison with the non-infused forearm, losartan did not affect basal forearm blood flow (95% confidence interval −5.5% to +7.3%) or sympathetically stimulated vasoconstriction in controls. However, the mean (SEM) blood flow in patients increased by 13(5)% and 26(7)% in response to 30 and 90 µg/min of losartan respectively (p < 0.001). Lower body negative pressure caused a reduction in forearm blood flow of 20(5)% in controls (p = 0.008) and 13(5)% (p = 0.08) in patients (p = 0.007, controls v patients). Blood flow at 90 µg/min of losartan correlated with plasma angiotensin II concentration (r = 0.77; p = 0.03). Responses to angiotensin II and noradrenaline did not differ between patients and controls.
Conclusions—Losartan causes acute local peripheral arteriolar vasodilatation in patients with heart failure but not in healthy control subjects. Endogenous angiotensin II directly contributes to basal peripheral arteriolar tone in patients with heart failure but does not augment sympathetically stimulated peripheral vascular tone.

 Keywords: angiotensin II;  heart failure;  peripheral vascular tone;  sympathetic nervous syste

Naturalness and Higgs Decays in the MSSM with a Singlet

The simplest extension of the supersymmetric standard model - the addition of one singlet superfield - can have a profound impact on the Higgs and its decays. We perform a general operator analysis of this scenario, focusing on the phenomenologically distinct scenarios that can arise, and not restricting the scope to the narrow framework of the NMSSM. We reexamine decays to four b quarks and four tau's, finding that they are still generally viable, but at the edge of LEP limits. We find a broad set of Higgs decay modes, some new, including those with four gluon final states, as well as more general six and eight parton final states. We find the phenomenology of these scenarios is dramatically impacted by operators typically ignored, specifically those arising from D-terms in the hidden sector, and those arising from weak-scale colored fields. In addition to sensitivity of m_Z, there are potential tunings of other aspects of the spectrum. In spite of this, these models can be very natural, with light stops and a Higgs as light as 82 GeV. These scenarios motivate further analyses of LEP data as well as studies of the detection capabilities of future colliders to the new decay channels presented.Comment: 3 figures, 1 appendix; version to appear in JHEP; typos fixed and additional references and acknowledgements adde

Dynamically Warped Theory Space and Collective Supersymmetry Breaking

We study deconstructed gauge theories in which a warp factor emerges dynamically and naturally. We present nonsupersymmetric models in which the potential for the link fields has translational invariance, broken only by boundary effects that trigger an exponential profile of vacuum expectation values. The spectrum of physical states deviates exponentially from that of the continuum for large masses; we discuss the effects of such exponential towers on gauge coupling unification. We also present a supersymmetric example in which a warp factor is driven by Fayet-Iliopoulos terms. The model is peculiar in that it possesses a global supersymmetry that remains unbroken despite nonvanishing D-terms. Inclusion of gravity and/or additional messenger fields leads to the collective breaking of supersymmetry and to unusual phenomenology.Comment: 28 pages LaTeX, JHEP format, 7 eps figures (v2: reference added

High Energy Gamma Ray Production from Proton Induced Reactions on D, C, Zn, Pb at Incident Energies of 104, 145, and 195 MeV

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Coping with the effects of fear of failure in young elite athletes

Coping with stress is an important element in effective functioning at the elite level in sports, and fear of failure (FF) is an example of a stressor that athletes experience. Three issues underpin the present preliminary study. First, the prevalence of problems attributed to FF in achievement settings. Second, sport is a popular and significant achievement domain for children and adolescents. Third, there is a lack of research on FF in sport among this population. Therefore, the objectives of the study were to examine the effects of FF on young athletes and to find out their coping responses to the effects of FF. Interviews were conducted individually with nine young elite ath­letes (5 males, 4 females; ages 14-17 years). It was inferred from the data that FF affected the athletes' well-being, interpersonal behavior, sport performance, and schoolwork. The athletes employed a combination of problem-focused, emotion-fo­cused, and avoidance-focused coping strategies, with avoidance strategies being the most frequently reported

The Leptonic Higgs as a Messenger of Dark Matter

We propose that the leptonic cosmic ray signals seen by PAMELA and ATIC result from the annihilation or decay of dark matter particles via states of a leptonic Higgs doublet to $\tau$ leptons, linking cosmic ray signals of dark matter to LHC signals of the Higgs sector. The states of the leptonic Higgs doublet are lighter than about 200 GeV, yielding large $\bar{\tau} \tau$ and $\bar{\tau} \tau \bar{\tau} \tau$ event rates at the LHC. Simple models are given for the dark matter particle and its interactions with the leptonic Higgs, for cosmic ray signals arising from both annihilations and decays in the galactic halo. For the case of annihilations, cosmic photon and neutrino signals are on the verge of discovery.Comment: 34 pages, 9 figures, minor typos corrected, references adde

The Evolutionary and Phylogeographic History of Woolly Mammoths: A Comprehensive Mitogenomic Analysis

Near the end of the Pleistocene epoch, populations of the woolly mammoth (Mammuthus primigenius) were distributed across parts of three continents, from western Europe and northern Asia through Beringia to the Atlantic seaboard of North America. Nonetheless, questions about the connectivity and temporal continuity of mammoth populations and species remain unanswered. We use a combination of targeted enrichment and high-throughput sequencing to assemble and interpret a data set of 143 mammoth mitochondrial genomes, sampled from fossils recovered from across their Holarctic range. Our dataset includes 54 previously unpublished mitochondrial genomes and significantly increases the coverage of the Eurasian range of the species. The resulting global phylogeny confirms that the Late Pleistocene mammoth population comprised three distinct mitochondrial lineages that began to diverge ∼1.0-2.0 million years ago (Ma). We also find that mammoth mitochondrial lineages were strongly geographically partitioned throughout the Pleistocene. In combination, our genetic results and the pattern of morphological variation in time and space suggest that male-mediated gene flow, rather than large-scale dispersals, was important in the Pleistocene evolutionary history of mammoths

Measurement of branching fraction ratios and CP asymmetries in B±→DCPK±B^{\pm} \to D_{CP}K^{\pm}

We report results on the decay $B^{-} \to D_{CP}K^{-}$ and its charge conjugate using a data sample of 85.4 million $B\bar{B}$ pairs recorded at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric $e^{+}e^{-}$ storage ring. Ratios of branching fractions of Cabibbo-suppressed to Cabibbo-favored processes are determined to be ${\cal B}(B^- \to D^0 K^-)/{\cal B}(B^- \to D^0 \pi^-)= 0.077 \pm 0.005(stat) \pm 0.006(sys)$, ${\cal B}(B^- \to D_1 K^-)/{\cal B}(B^- \to D_1 \pi^-) = 0.093 \pm 0.018(stat) \pm 0.008(sys)$ and ${\cal B}(B^- \to D_2 K^-)/{\cal B}(B^- \to D_2 \pi^-) = 0.108 \pm 0.019(stat) \pm 0.007(sys)$ where the indices 1 and 2 represent the CP=+1 and CP=$-$1 eigenstates of the $D^{0}-\bar{D^{0}}$ system, respectively. We find the partial-rate charge asymmetries for $B^{-} \to D_{CP}K^{-}$ to be ${\cal{A}}_1 = 0.06 \pm 0.19(stat) \pm 0.04(sys)$ and ${\cal{A}}_2 = -0.19 \pm 0.17(stat) \pm 0.05(sys)$.Comment: 10 pages, 3 figures, submitted to Physical Review