Direct Evidence from Spitzer for a low-luminosity AGN at the center of the Elliptical Galaxy NGC 315

We present the {\it Spitzer} Space Telescope InfraRed Array Camera (IRAC) and Multiband Imaging Photometer (MIPS) observations of the elliptical galaxy NGC 315. After removal of the host galaxy's stellar emission, we detected for the first time an infrared-red nucleus in NGC 315. We measured the spectral energy distribution (SED) for this active nucleus with wavelength range covering from radio to X-ray, and obtained the bolometric luminosity of $\rm L_{bol} \approx 1.9 \times 10^{43} ergs s^{-1}$, corresponding to an extremely low Eddington ratio (L/L$_{\rm Edd}$) of 4.97 $\times$ 10$^{-4}$. Our results confirm that the physical nature of the nucleus of NGC 315 is a low-luminosity AGN, consistent with the recent optical and {\it Chandra} X-ray observations.Comment: 4 pages, accepted for publication in ApJ Letter

Vacuum State of Lattice Gauge Theory with Fermions in 2+1 Dimensions

We investigate the vacuum state of the lattice gauge theory with fermions in 2+1 dimensions. The vacuum in the Hermite form for the fermion part is obtained; the vacuum in the unitary form has been proposed by Luo and Chen. It is shown that the Hermite vacuum has a lower energy than the unitary one through the variational method.Comment: 16 pages, 5 embedded PS figures, LaTeX with special styl

Political participation: the vocational motivations of Labour party employees

Party employees are an under-researched group in political science. This article begins to address this oversight by examining Labour Party employees using new quantitative and qualitative data. It argues that party employment should be regarded as a form of political participation and as a consequence, existing models of political participation can be utilised to help explain why people work for political parties. After testing these propositions, the article concludes that existing models are indeed helpful in explaining the motivations for party employment

Mitigation of Pulsed Interference to Redshifted HI and OH Observations between 960 and 1215 MHz

The neutral hydrogen 21-cm spectral line (1420.4 MHz) and the four 18-cm lines of the hydroxyl molecule (1612-1720 MHz) are observable at redshifts which put their measured line frequencies well below their protected frequency bands. Part of the redshift ranges (z = 0.171-0.477 for HI and z = 0.37-0.73 for OH) fall in the 960 to 1215 MHz band that is allocated to aircraft navigation. Most of the signals in this band are pulsed emissions of low duty cycle so much of the time between pulses is interference free. This paper outlines the structure and measured properties of signals in this band and demonstrates a signal processing strategy that is effective at removing the pulsed signals from spectra at sensitivities produced by several hours of integration.Comment: Astronomical Journal, May 2005, in pres

Direct Improvement of Hamiltonian Lattice Gauge Theory

We demonstrate that a direct approach to improving Hamiltonian lattice gauge theory is possible. Our approach is to correct errors in the Kogut-Susskind Hamiltonian by incorporating additional gauge invariant terms. The coefficients of these terms are chosen so that the order $a^2$ classical errors vanish. We conclude with a brief discussion of tadpole improvement in Hamiltonian lattice gauge theory.Comment: 9 page

Pancreatic cysts suspected to be branch duct intraductal papillary mucinous neoplasm without concerning features have low risk for development of pancreatic cancer.

BackgroundThe risk of developing pancreatic cancer is uncertain in patients with clinically suspected branch duct intraductal papillary mucinous neoplasm (BD-IPMN) based on the "high-risk stigmata" or "worrisome features" criteria proposed in the 2012 international consensus guidelines ("Fukuoka criteria").MethodsRetrospective case series involving patients referred for endoscopic ultrasound (EUS) of indeterminate pancreatic cysts with clinical and EUS features consistent with BD-IPMN. Rates of pancreatic cancer occurring at any location in the pancreas were compared between groups of patients with one or more Fukuoka criteria ("Highest-Risk Group", HRG) and those without these criteria ("Lowest-Risk Group", LRG).ResultsAfter exclusions, 661 patients comprised the final cohort (250 HRG and 411 LRG patients), 62% female with an average age of 67 years and 4 years of follow up. Pancreatic cancer, primarily adenocarcinoma, occurred in 60 patients (59 HRG, 1 LRG). Prevalent cancers diagnosed during EUS, immediate surgery, or first year of follow up were found in 48/661 (7.3%) of cohort and exclusively in HRG (33/77, 42.3%). Using Kaplan-Meier method, the cumulative incidence of cancer at 7 years was 28% in HRG and 1.2% in LRG patients (P<0.001).ConclusionsThis study supports using Fukuoka criteria to stratify the immediate and long-term risks of pancreatic cancer in presumptive BD-IPMN. The risk of pancreatic cancer was highest during the first year and occurred exclusively in those with "high-risk stigmata" or "worrisome features" criteria. After the first year all BD-IPMN continued to have a low but persistent cancer risk

Intersublevel Polaron Dephasing in Self-Assembled Quantum Dots

Polaron dephasing processes are investigated in InAs/GaAs dots using far-infrared transient four wave mixing (FWM) spectroscopy. We observe an oscillatory behaviour in the FWM signal shortly (< 5 ps) after resonant excitation of the lowest energy conduction band transition due to coherent acoustic phonon generation. The subsequent single exponential decay yields long intraband dephasing times of 90 ps. We find excellent agreement between our measured and calculated FWM dynamics, and show that both real and virtual acoustic phonon processes are necessary to explain the temperature dependence of the polarization decay.Comment: 10 pages, 4 figures, submitted to Phys Rev Let

Feeling Safe in the Dark : Examining the Effect of Entrapment, Lighting Levels, and Gender on Feelings of Safety and Lighting Policy Acceptability

This research examined to what extent physical factors, notably lighting and entrapment (blocked escape), and individual factors, notably gender, affect feelings of safety and the acceptability of reduced lighting levels. The authors reasoned that acceptability of reduced street lighting depends on perceived safety, which in turn depends on entrapment, lighting, and gender. Virtual representations of a residential street were used, systematically manipulating entrapment and lighting levels. As expected, people felt less safe in lower lighting and higher entrapment settings, and these settings were evaluated as less acceptable. Although women perceived a situation as less safe compared with men, the authors found no gender differences in acceptability, which extends previous research. Importantly, as hypothesized, perceived safety mediated the effect of lighting on acceptability levels, suggesting that people can accept lower lighting levels when social safety is not threatened

A Dynamical Analysis of the Suitability of Prehistoric Spheroids from the Cave of Hearths as Thrown Projectiles

Spheroids are ball-shaped stone objects found in African archaeological sites dating from 1.8 million years ago (Early Stone Age) to at least 70,000 years ago (Middle Stone Age). Spheroids are either fabricated or naturally shaped stones selected and transported to places of use making them one of the longest-used technologies on record. Most hypotheses about their use suggest they were percussive tools for shaping or grinding other materials. However, their size and spherical shape make them potentially useful as projectile weapons, a property that, uniquely, humans have been specialised to exploit for millions of years. Here we show (using simulations of projectile motions resulting from human throwing) that 81% of a sample of spheroids from the late Acheulean (Bed 3) at the Cave of Hearths, South Africa afford being thrown so as to inflict worthwhile damage to a medium-sized animal over distances up to 25 m. Most of the objects have weights that produce optimal levels of damage from throwing, rather than simply being as heavy as possible (as would suit other functions). Our results show that these objects were eminently suitable for throwing, and demonstrate how empirical research on behavioural tasks can inform and constrain our theories about prehistoric artefacts