Nanoscale quantum dot infrared sensors with photonic crystal cavity

We report high performance infrared sensors that are based on intersubband transitions in nanoscale self-assembled quantum dots combined with a microcavity resonator made with a high-index-contrast two-dimensional photonic crystal. The addition of the photonic crystal cavity increases the photocurrent, conversion efficiency, and the signal to noise ratio (represented by the specific detectivity D*) by more than an order of magnitude. The conversion efficiency of the detector at Vb=–2.6 V increased from 7.5% for the control sample to 95% in the PhC detector. In principle, these photonic crystal resonators are technology agnostic and can be directly integrated into the manufacturing of present day infrared sensors using existing lithographic tools in the fabrication facility

A calculation of the Lepage-Mackenzie scale for the lattice axial and vector currents

We calculate the perturbative scales (q*) for the axial and vector currents for the Wilson action, with and without tadpole improvement, using Lepage and Mackenzie's formalism. The scale for the pseudoscalar density (times the mass) is computed as well. Contrary to naive expectation, tadpole improvement reduces q* by only a small amount for the operators we consider. We also discuss the use of a nonperturbative coupling to calculate the perturbative scale.Comment: 13 pages. One postscript figur

Hidden Local Symmetry for Anomalous Processes with Isospin/SU(3) Breaking Effects

We show that isospin/SU(3) breaking terms can be introduced to the anomalous VVP coupling in the hidden local symmetry scheme without changing Wess-Zumino-Witten term in the low-energy limit. We make the analysis for anomalous processes of 2-body and 3-body decays; radiative vector meson decays(V \to P\gamma), conversion decays of photon into a lepton pair(V \to P l^+ l^-) and hadronic anomalous decays(V \to PPP). The predictions successfully reproduce all experimental data of anomalous decays. In particular, we predict the decay widths of \rho^0 \to \pi^0 \gamma and \phi \to \eta' \gamma as 101 \pm 9 keV and 0.508 \pm 0.035 keV, respectively, which will be tested in the DAFNE \phi-factory. Moreover, prediction is also made for \phi \to \pi^0 e^+ e^-, \rho \to 3\pi, K^* \to K \pi \pi and so on, for which only the experimental upper bounds are available now.Comment: 19 pages, 4 tables, no figur

Weak Decays Beyond Leading Logarithms

We review the present status of QCD corrections to weak decays beyond the leading logarithmic approximation including particle-antiparticle mixing and rare and CP violating decays. After presenting the basic formalism for these calculations we discuss in detail the effective hamiltonians for all decays for which the next-to-leading corrections are known. Subsequently, we present the phenomenological implications of these calculations. In particular we update the values of various parameters and we incorporate new information on m_t in view of the recent top quark discovery. One of the central issues in our review are the theoretical uncertainties related to renormalization scale ambiguities which are substantially reduced by including next-to-leading order corrections. The impact of this theoretical improvement on the determination of the Cabibbo-Kobayashi-Maskawa matrix is then illustrated in various cases.Comment: 229 pages, 32 PostScript figures (included); uses RevTeX, epsf.sty, rotate.sty, rmpbib.sty (included), times.sty (included; requires LaTeX 2e); complete PostScript version available at ftp://feynman.t30.physik.tu-muenchen.de/pub/preprints/tum-100-95.ps.gz or ftp://feynman.t30.physik.tu-muenchen.de/pub/preprints/tum-100-95.ps2.gz (scaled down and rotated version to print two pages on one sheet of paper

Social and Behavioral Rhythms is Related to the Perception of Quality of Life in Old Adults

Introduction: The purpose is to verify in old adults if social and behavioral rhythms (SBRs) are correlated with a positive perception of the quality of life (QoL). Social and behavioral rhythms and related circadian biorhythms are known as central points in the pathophysiology of bipolar disorders. A secondary aim is to see if a similar relationship can be found in Major Depressive Disorder (MDD) in old adults. Sample: 141 people aged ≥65 years (58.9% Female). Methods: Each subject was evaluated using the Social and Behavioral Rhythms Scale (in which higher scores show more dysfunctional SRBs); SF-12 for QoL and a screening tool for depressive symptoms. They underwent a medical evaluation and blood level assays including cholesterol and triglycerides. The medical diagnoses including MDD were taken into account. Results: The Social and Behavioral Rhythms Scale score correlated inversely with SF-12 score (p<0.001) and positively with PHQ9 (p<0.0001). People with MDD had a higher score on social rhythms than controls without (p<0.01). The study highlighted, for the first time, that social and behavioral rhythms have a role in old adults living in the community. Conclusion: Further longitudinal studies with a sufficient number of individuals will be required to confirm these data and clarify causal links of the association

Leptonic and Semileptonic Decays of Charm and Bottom Hadrons

We review the experimental measurements and theoretical descriptions of leptonic and semileptonic decays of particles containing a single heavy quark, either charm or bottom. Measurements of bottom semileptonic decays are used to determine the magnitudes of two fundamental parameters of the standard model, the Cabibbo-Kobayashi-Maskawa matrix elements $V_{cb}$ and $V_{ub}$. These parameters are connected with the physics of quark flavor and mass, and they have important implications for the breakdown of CP symmetry. To extract precise values of $|V_{cb}|$ and $|V_{ub}|$ from measurements, however, requires a good understanding of the decay dynamics. Measurements of both charm and bottom decay distributions provide information on the interactions governing these processes. The underlying weak transition in each case is relatively simple, but the strong interactions that bind the quarks into hadrons introduce complications. We also discuss new theoretical approaches, especially heavy-quark effective theory and lattice QCD, which are providing insights and predictions now being tested by experiment. An international effort at many laboratories will rapidly advance knowledge of this physics during the next decade.Comment: This review article will be published in Reviews of Modern Physics in the fall, 1995. This file contains only the abstract and the table of contents. The full 168-page document including 47 figures is available at http://charm.physics.ucsb.edu/papers/slrevtex.p

Moderate exercise improves cognitive function in healthy elderly people: Results of a randomized controlled trial

BACKGROUND: Physical activity in the elderly is recommended by international guidelines to protect against cognitive decline and functional impairment. OBJECTIVE: This Randomized Controlled Trial (RCT) was set up to verify whether medium-intensity physical activity in elderly people living in the community is effective in improving cognitive performance. DESIGN: RCT with parallel and balanced large groups. SETTING: Academic university hospital and Olympic gyms. SUBJECTS: People aged 65 years old and older of both genders living at home holding a medical certificate for suitability in non-competitive physical activity. METHODS: Participants were randomized to a 12-week, 3 sessions per week moderate physical activity program or to a control condition focused on cultural and recreational activities in groups of the same size and timing as the active intervention group. The active phase integrated a mixture of aerobic and anaerobic exercises, including drills of “life movements”, strength and balance. The primary outcome was: any change in Addenbrooke's Cognitive Examination Revised (ACE-R) and its subscales. RESULTS: At the end of the trial, 52 people completed the active intervention, and 53 people completed the control condition. People in the active intervention improved on the ACE-R (ANOVA: F(1;102)=4.32, p=0.040), and also showed better performances on the memory (F(1;102)=5.40 p=0.022) and visual-space skills subscales of the ACE-R (F(1;102)=4.09 p=0.046). CONCLUSION: A moderate-intensity exercise administered for a relatively short period of 12 weeks is capable of improving cognitive performance in a sample of elderly people who live independently in their homes. Clinical Trials Registration No: NCT0385811

Treatment with green tea extract attenuates secondary inflammatory response in an experimental model of spinal cord trauma

In this study, we evaluated the effect of green tea extract (that was administered 25 mg/kg intraperitoneal at 1 and 6 h after injury) in experimental animal model of spinal cord injury. The spinal cord trauma was induced by the application of vascular clips to the dura via a four-level T5–T8 laminectomy. Spinal cord injury in mice resulted in severe trauma characterised by oedema, neutrophilic infiltration and apoptosis. Also, immunohistochemical examination demonstrated a marked increase in immune reactivity for nitrotyrosine. All parameters of inflammation were attenuated by green tea extract. The degree of spinal cord inflammation, nitrotyrosine, poli (ADP-ribosio) synthetase (PARS) and neutrophilic infiltration was markedly reduced. Green tea extract significantly ameliorated the recovery of limb function. Values shown are mean ± SE mean of ten mice for each group. *p < 0.01 versus sham, °p < 0.01 versus spinal cord injury. Taken together, our results clearly demonstrate that green tea extract treatment ameliorates spinal cord injury oxidative stress

Olprinone Attenuates the Acute Inflammatory Response and Apoptosis after Spinal Cord Trauma in Mice

BACKGROUND: Olprinone hydrochloride is a newly developed compound that selectively inhibits PDE type III and is characterized by several properties, including positive inotropic effects, peripheral vasodilatory effects, and a bronchodilator effect. In clinical settings, olprinone is commonly used to treat congestive cardiac failure, due to its inotropic and vasodilating effects. The mechanism of these cardiac effects is attributed to increased cellular concentrations of cAMP. The aim of the present study was to evaluate the pharmacological action of olprinone on the secondary damage in experimental spinal cord injury (SCI) in mice. METHODOLOGY/PRINCIPAL FINDINGS: Traumatic SCI is characterized by an immediate, irreversible loss of tissue at the lesion site, as well as a secondary expansion of tissue damage over time. Although secondary injury should be preventable, no effective treatment options currently exist for patients with SCI. Spinal cord trauma was induced in mice by the application of vascular clips (force of 24 g) to the dura via a four-level T5-T8 laminectomy. SCI in mice resulted in severe trauma characterized by edema, neutrophil infiltration, and production of inflammatory mediators, tissue damage, apoptosis, and locomotor disturbance. Olprinone treatment (0.2 mg/kg, i.p.) 1 and 6 h after the SCI significantly reduced: (1) the degree of spinal cord inflammation and tissue injury (histological score), (2) neutrophil infiltration (myeloperoxidase activity), (3) nitrotyrosine formation, (4) pro-inflammatory cytokines, (5) NF-kappaB expression, (6) p-ERK1/2 and p38 expression and (7) apoptosis (TUNEL staining, FAS ligand, Bax and Bcl-2 expression). Moreover, olprinone significantly ameliorated the recovery of hind-limb function (evaluated by motor recovery score). CONCLUSIONS/SIGNIFICANCE: Taken together, our results clearly demonstrate that olprinone treatment reduces the development of inflammation and tissue injury associated with spinal cord trauma