Vilnius Multicolor CCD Photometry of the Open Cluster NGC 752

AbstractWe have performed multicolor CCD observations of the central area of NGC 752 to search for faint, low-mass members of this open cluster. Four 12' x 12' fields were taken on the 1.8 m Vatican Advanced Technology Telescope (Mt. Graham, Arizona) using a 4K CCD camera and eight intermediate-band filters of the Strömvil (Strömgren + Vilnius) system. In this paper we present a catalog of photometry for 405 stars down to the limiting magnitude V = 18.5, which contains V magnitudes and color indices of the Vilnius system, together with photometric determinations of spectral types, absolute magnitudes

Indication, from Pioneer 10/11, Galileo, and Ulysses Data, of an Apparent Anomalous, Weak, Long-Range Acceleration

Radio metric data from the Pioneer 10/11, Galileo, and Ulysses spacecraft indicate an apparent anomalous, constant, acceleration acting on the spacecraft with a magnitude $\sim 8.5\times 10^{-8}$ cm/s$^2$, directed towards the Sun. Two independent codes and physical strategies have been used to analyze the data. A number of potential causes have been ruled out. We discuss future kinematic tests and possible origins of the signal.Comment: Revtex, 4 pages and 1 figure. Minor changes for publicatio

Human mucocutaneous leishmaniasis in Três Braços, Bahia - Brazil : an area of Leishmania braziliensis braziliensis transmission. I. laboratory diagnosis

Foram analisados os dados clínicos de 182 pacientes com leishmaniose cutânea, provavelmente causada por Leishmania braziliensis braziliensis. Sessenta e oito por cento apresentavam uma única lesão, usualmente uma úlcera, na terça parte inferior anterior da tíbia. Todos os grupos etários estavam representados e muitos apresentaram histórico de um a dois meses. Treze por cento apresentavam lesões fechadas de natureza verrucosa ou em placa. Após tratamento, a evolução destas lesões foi relacionada à regularidade da terapia por antimônio. Embora a cura usualmente ocorresse em três meses, o tempo de cicatrização, após o início de tratamento, foi variável e relativo ao tamanho da lesão (p < 0.01). Em geral a lesão fechava quando era dado suficiente antimônio como tratamento. Sete entre dez pacientes que apresentavam teste cutâneo negativo para leishmania tomavam positivos após o tratamento. Observou-se por fluorescência indireta, um declínio significante nos títulos de anticorpos em pacientes acompanhados durante e após a terapia. _______________________________________________________________________________ ABSTRACTThe clinical records of 182 patients with cutaneous leishmaniasis probably due to Leishmania braziliensis braziliensis are analysed. 68% had a single lesion which was usually an ulceron the lower anterior tibial third. Many had short histories of one to two months and all age groups were represented 13% had closed lesions of a verrucose or plaque like nature. Evolution of these skin lesions after treatment was related to the regularity of antimony therapy. Although healing usually occurred in three months, the time to scarring after commencing treatment was variable and related to the size ofthe lesion (p < 0.01). Usually if sufficient antimony treatment was given the lesion closed. Seven of the ten patients with initially negative leishmanin skin tests converted to positive after treatment. A significant decline of indirect fluorescent antibody titres occurred in patients followed, during and after therapy

The most creative organization in the world? The BBC, 'creativity' and managerial style

The managerial styles of two BBC directors-general, John Birt and Greg Dyke, have often been contrasted but not so far analysed from the perspective of their different views of 'creative management'. This article first addresses the orthodox reading of 'Birtism'; second, it locates Dyke's 'creative' turn in the wider context of fashionable neo-management theory and UK government creative industries policy; third, it details Dyke's drive to change the BBC's culture; and finally, it concludes with some reflections on the uncertainties inherent in managing a creative organisation

A Tale of Two Trails: Exploring Different Paths to Success

This comparative case study investigates 2 successful community trail initiatives, using the Active Living By Design (ALBD) Community Action Model as an analytical framework. The model includes 5 strategies: preparation, promotion, programs, policy, and physical projects

Quantum Electronics

Contains report on ten research projects split into three sections.Joint Services Electronics Program (Contract DAAG29-78-C-0020)National Science Foundation (Grant PHY77-07156)U. S. Air Force-Office of Scientific Research (Grant AFOSR-3042)National Science Foundation (Grant ENG77-24981

On the Nature of Stars with Planets

We consider the metallicities and kinematics of nearby stars known to have planetary-mass companions in the general context of the overall properties of the local Galactic Disk. We have used Stromgren photometry to determine abundances for both the extrasolar-planet host stars and for a volume-limited sample of 486 F, G and K stars selected from the Hipparcos catalogue. The latter data show that the Sun lies near the modal abundance of the disk, with over 45% of local stars having super-solar metallicities. Twenty of the latter stars (4.1%) are known to have planetary-mass companions. Using that ratio to scale data for the complete sample of planetary host stars, we find that the fraction of stars with extrasolar planets rises sharply with increasing abundance, confirming previous results. However, the frequency remains at the 3-4% level for stars within 0.15 dex of solar abundance, and falls to ~1% only for stars with abundances less than half solar. Given the present observational constraints, both in velocity precision and in the available time baseline, these numbers represent a lower limit to the frequency of extrasolar planetary systems. A comparison between the kinematics of the planetary host stars and a representative sample of disk stars suggests that the former have an average age which is ~60% of the latter.Comment: 46 pages, 13 figures; accepted for PAS

Quantum Electronics

Contains reports on eleven research projects.Air Force Rome Air Development Center (in collaboration with C.C. Leiby Jr)U.S. Air Force - Rome Air Development Center (Contract F19628-80-C-0077)National Science Foundation (Grant PHY79-09739)Joint Services Electronics Program (Contract DAAG29-80-C-0104)Air Force Geophysics Laboratory (Contract F 19628-79-C-0082)National Science Foundation (Grant DAR80-08752)National Science Foundation (Grant ECS79-19475)National Science Foundation (Grant ECS80-17705)National Science Foundation (Grant ENG79-09980

Quantum Electronics

Contains reports on eight research projects divided into three sections.National Science Foundation (Grant PHY79-09739)Joint Services Electronics Program (Contract DAAG29-78-C-0020)U.S. Air Force Geophysics Laboratory (AFSC) (Contract F19628-79-C-0082)National Science Foundation (Grant ENG79-09980

Matched sizes of activating and inhibitory receptor/ligand pairs are required for optimal signal integration by human Natural Killer cells

It has been suggested that receptor-ligand complexes segregate or co-localise within immune synapses according to their size, and this is important for receptor signaling. Here, we set out to test the importance of receptor-ligand complex dimensions for immune surveillance of target cells by human Natural Killer (NK) cells. NK cell activation is regulated by integrating signals from activating receptors, such as NKG2D, and inhibitory receptors, such as KIR2DL1. Elongating the NKG2D ligand MICA reduced its ability to trigger NK cell activation. Conversely, elongation of KIR2DL1 ligand HLA-C reduced its ability to inhibit NK cells. Whereas normal-sized HLA-C was most effective at inhibiting activation by normal-length MICA, only elongated HLA-C could inhibit activation by elongated MICA. Moreover, HLA-C and MICA that were matched in size co-localised, whereas HLA-C and MICA that were different in size were segregated. These results demonstrate that receptor-ligand dimensions are important in NK cell recognition, and suggest that optimal integration of activating and inhibitory receptor signals requires the receptor-ligand complexes to have similar dimensions