On Congruence Lattices of Nilsemigroups

We prove that the congruence lattice of a nilsemigroup is modular if and only if the width of the semigroup, as a poset, is at most two, and distributive if and only if its width is one. In the latter case, such semigroups therefore coincide with the nil Δ \u3eΔ Δ -semigroups. It is further shown that if a finitely generated nilsemigroup has modular congruence lattice, then the semigroup is finite

Large Deployable Reflector (LDR) system concept and technology definition study. Volume 2: Technology assessment and technology development plan

A study was conducted to define reasonable and representative LDR system concepts for the purpose of defining a technology development program aimed at providing the requisite technological capability necessary to start LDR development by the end of 1991. This volume presents thirteen technology assessments and technology development plans, as well as an overview and summary of the LDR concepts. Twenty-two proposed augmentation projects are described (selected from more than 30 candidates). The five LDR technology areas most in need of supplementary support are: cryogenic cooling; astronaut assembly of the optically precise LDR in space; active segmented primary mirror; dynamic structural control; and primary mirror contamination control. Three broad, time-phased, five-year programs were synthesized from the 22 projects, scheduled, and funding requirements estimated

Achieving a wide field near infrared camera for the Calar Alto 3.5m telescope

The ongoing development of large infrared array detectors has enabled wide field, deep surveys to be undertaken. There are, however, a number of challenges in building an infrared instrument which has both excellent optical quality and high sensitivity over a wide field. We discuss these problems in the context of building a wide field imaging camera for the 3.5m telescope at Calar Alto with the new 2K*2K HgCdTe HAWAII-2 focal plane array. Our final design is a prime focus camera with a 15' field-of-view, called Omega 2000. To achieve excellent optical quality over the whole field, we have had to dispense with the reimaging optics and cold Lyot stop. We show that creative baffling schemes, including the use of undersized baffles, can compensate for the lost K band sensitivity. A moving baffle will be employed in Omega 2000 to allow full transmission in the non-thermal J and H bands.Comment: To appear in the SPIE proceedings of ``Optical and IR Telescope Instrumentation and Detectors'', Munich, March 200

Jet-like correlations between Forward- and Mid- rapidity in p+p, d+Au and Au+Au collisions from STAR at 200 GeV

In this proceedings we present STAR measurements of two particle azimuthal correlations between trigger particles at mid-rapidity ($|\eta|<$ 1) and associated particles at forward rapidities (2.7 $<|\eta|<$ 3.9) in p+p, d+Au and Au+Au collisions at $\sqrt{s_{NN}}$= 200 GeV. Two particle azimuthal correlations between a mid-rapidity trigger particle and forward-rapidity associated particles preferably probe large-x quarks scattered off small-x gluons in RHIC collisions. Comparison of the separate d- and Au-side measurements in d+Au collisions may potentially probe gluon saturation and the presence of Color Glass Condensate. In Au+Au collisions quark energy loss can be probed at large rapidities, which may be different from gluon energy loss measured at mid-rapidity.Comment: Quark Matter 06 Conference proceedings, submitted to Journal of Phys.

Job Anxiety, Work-Related Psychological Illness and Workplace Performance

This paper uses matched employee-employer data from the British Workplace Employment Relations Survey (WERS) 2004 to examine the determinants of employee job anxiety and work-related psychological illness. Job anxiety is found to be strongly related to the demands of the job as measured by factors such as occupation, education and hours of work. Average levels of employee job anxiety, in turn, are positively associated with work-related psychological illness among the workforce as reported by managers. The paper goes on to consider the relationship between psychological illness and workplace performance as measured by absence, turnover and labour productivity. Work-related psychological illness is found to be negatively associated with several measures of workplace performance.job anxiety, stress, absence, labour productivity

Molecular Mechanisms of FSH Muscular Dystrophy Pathogenesis

Discussion of a new research initiative at UMass Medical School focused on the pathogenesis of Facioscapulohumeral Muscular Dystrophy (FSHD) and efforts towards diagnostics and therapeutics. This presentation is part of the retreat mini-symposium entitled: Neuromuscular Diseases: Pathogenesis and the Road to Therapeutics

Physics with Identified Particles at STAR

New physics results with identified particles at STAR are presented. Measurements at low $p_T$ address bulk properties of the collision, while those at high $p_T$ address jet energy loss in the bulk matter produced. Between these extremes, measurements at intermediate $p_T$ address the interplay between jets and the bulk. We highlight: measurements of $v_2$ fluctuations as a new, sensitive probe of the initial conditions and the equation of state; correlations involving multi-strange particles, along with ratios of identified particles to test coalescence as a mechanism of particle production at intermediate $p_T$; three particle azimuthal correlation to search for conical emission; and the energy and particle-type dependence of hadron production at high $p_T$ to study quark and gluon jet energy loss.Comment: 9 pages, 7 figures. To appear in the proceedings of the 19th International Conference on Ultra-Relativistic Nucleus-Nucleus Collisions (Quark Matter 2006), Shanghai, China, November 14-20, 200

π,K,p\pi, K, p and pˉ\bar{p} production from Au+Au collisions at sNN=62.4\sqrt{s_{_{NN}}} = 62.4 GeV

The preliminary results of $\pi^{\pm}, K^{\pm}, p$ and $\bar{p}$ spectra are reported from Au+Au collisions at $\sqrt{s_{_{NN}}} = 62.4$ GeV. Particle identification is from the Time Projection Chamber and Time-of-Flight system at STAR. The nuclear modification factor $R_{CP}$ for mesons ($\pi^{\pm}, K^{\pm}$) and baryons ($p, \bar{p}$) will also be discussed.Comment: 5 pages, 4 figures, Contributed to 8th International Conference on Strangeness in Quark Matter (SQM 2004),to be published in Journal of Physics