Protoplanetary Disk Mass Distribution in Young Binaries

We present millimeter-wave continuum images of four wide (separations 210-800 AU) young stellar binary systems in the Taurus-Auriga star-forming region. For all four sources, the resolution of our observations is sufficient to determine the mm emission from each of the components. In all four systems, the primary star's disk has stronger millimeter emission than the secondary and in three of the four, the secondary is undetected; this is consistent with predictions of recent models of binary formation by fragmentation. The primaries' circumstellar disk masses inferred from these observations are comparable to those found for young single stars, confirming that the presence of a wide binary companion does not prevent the formation of a protoplanetary disk. Some of the secondaries show signatures of accretion (H-alpha emission and K - L excesses), yet their mm fluxes suggest that very little disk mass is present.Comment: Accepted by ApJ, to appear Feb. 2003; 9 pages, 5 postscript figures, uses aastex, emulateapj5, and apjfonts style files. Also available at http://astro.swarthmore.edu/~jensen/publications.htm

Harm reduction programs in the U.S.A.: emerging trends

[ES] Actualmente, en E.E.U.U los esfuerzos a favor de los programas de reducción de daños en materia de drogas son mínimos, a pesar de que estos programas aparecieran en los años 70. El sistema de justicia penal se ha convertido, desde los años 80, en el elemento predominante para controlar a los usuarios de drogas ilegales. Esto se refleja en el aumento del número de detenciones relacionadas con las drogas, así como en un mayor número de personas en prisión condenadas por este tipo de delitos. A pesar de, y en algunos casos como reacción a la considerable generalización del uso del derecho penal y el encarcelamiento para hacer frente a la delincuencia relacionada con la droga, las políticas de reducción de daños están apareciendo en varios estados, particularmente en el oeste.[EU] Nahiz eta 70. hamarkadan jaio ziren min murrizketa programak, gaur egun Estatu Batuetan ez da beraien alde gauza gehiegirik egiten Justizi penalaren sistema 80. hamarkadatik bihurtu da kontrol sistemarik garrantzitsuena drogen arloan. Honek bere islada hainbat eta hainbat atxiloketetan du, baita kartzelan arazo honengatik dagoen jende kopuruan. Hala ere esan daiteke, nahiz eta gero eta era orokorragoz kartzela zigorren bidez egiten zaion aurre drogen arazoei, esan beharra dago, gero eta erreztasun handiagoz erabiltzen hasten direla mina murrizten duten politika programak.[FR] Actuellement, en E.E.U.U les efforts en faveur des programmes de réduction de dommages en matière de drogues sont minimaux, bien que ces programmes apparaissent dans les années 70. Le système de justice pénale est devenu, depuis les années 80, l’élément prédominant pour contrôler aux consommateurs des drogues illégales. Ceci se reflète dans l’augmentation du nombre de détentions en rapport avec les drogues, ainsi que dans un plus grand nombre de personnes en prison condamnées par ce type d’infractions. Malgré, et dans quelques cas comme réaction, la généralisation de l’utilisation du droit pénal et l’emprisonnement pour faire face à la délinquance en rapport avec la drogue, les politiques de réduction des dommages apparaissent dans plusieurs états, particulièrement dans l’ouest.[EN] The topic of harm reduction programs for illegal substances in the U.S.A. today is a rather minimal endeavor, in spite of these programs began here during the 1970s. The dominant method of handling users of illegal drugs since 1980 has increasingly become the criminal justice system. This is reflected in increases in arrests for drug offenses and increases in the numbers of persons in prisons convicted of drug offenses. Despite, and in some cases in reaction to, the immense expansion of the use of criminal law and incarceration in the handling of drug offenders, harm reduction policies are emerging in several states, particularly in the west

Harm reduction programs in the U.S.A.: emerging trends

[ES] Actualmente, en E.E.U.U los esfuerzos a favor de los programas de reducción de daños en materia de drogas son mínimos, a pesar de que estos programas aparecieran en los años 70. El sistema de justicia penal se ha convertido, desde los años 80, en el elemento predominante para controlar a los usuarios de drogas ilegales. Esto se refleja en el aumento del número de detenciones relacionadas con las drogas, así como en un mayor número de personas en prisión condenadas por este tipo de delitos. A pesar de, y en algunos casos como reacción a la considerable generalización del uso del derecho penal y el encarcelamiento para hacer frente a la delincuencia relacionada con la droga, las políticas de reducción de daños están apareciendo en varios estados, particularmente en el oeste.[EU] Nahiz eta 70. hamarkadan jaio ziren min murrizketa programak, gaur egun Estatu Batuetan ez da beraien alde gauza gehiegirik egiten Justizi penalaren sistema 80. hamarkadatik bihurtu da kontrol sistemarik garrantzitsuena drogen arloan. Honek bere islada hainbat eta hainbat atxiloketetan du, baita kartzelan arazo honengatik dagoen jende kopuruan. Hala ere esan daiteke, nahiz eta gero eta era orokorragoz kartzela zigorren bidez egiten zaion aurre drogen arazoei, esan beharra dago, gero eta erreztasun handiagoz erabiltzen hasten direla mina murrizten duten politika programak.[FR] Actuellement, en E.E.U.U les efforts en faveur des programmes de réduction de dommages en matière de drogues sont minimaux, bien que ces programmes apparaissent dans les années 70. Le système de justice pénale est devenu, depuis les années 80, l’élément prédominant pour contrôler aux consommateurs des drogues illégales. Ceci se reflète dans l’augmentation du nombre de détentions en rapport avec les drogues, ainsi que dans un plus grand nombre de personnes en prison condamnées par ce type d’infractions. Malgré, et dans quelques cas comme réaction, la généralisation de l’utilisation du droit pénal et l’emprisonnement pour faire face à la délinquance en rapport avec la drogue, les politiques de réduction des dommages apparaissent dans plusieurs états, particulièrement dans l’ouest.[EN] The topic of harm reduction programs for illegal substances in the U.S.A. today is a rather minimal endeavor, in spite of these programs began here during the 1970s. The dominant method of handling users of illegal drugs since 1980 has increasingly become the criminal justice system. This is reflected in increases in arrests for drug offenses and increases in the numbers of persons in prisons convicted of drug offenses. Despite, and in some cases in reaction to, the immense expansion of the use of criminal law and incarceration in the handling of drug offenders, harm reduction policies are emerging in several states, particularly in the west

A Connection between Submillimeter Continuum Flux and Separation in Young Binaries

We have made sensitive 800-micron continuum observations of low-mass, pre-main sequence (PMS) binary stars with projected separations less than 25 AU in Taurus-Auriga to study disks in the young binary environment. We did not detect any of the observed binaries, with typical 3-sigma upper limits of about 30 mJy. Combining our observations with previous 1300-micron observations of PMS Taurus binaries by Beckwith et al. (1990) and others, we find that the submillimeter fluxes from binaries with projected separations between 1 AU and 50 AU are significantly lower than fluxes from binaries with projected separations > 50 AU. The submillimeter fluxes from the wider binaries are consistent with those of PMS single stars. This may indicate lower disk surface densities and masses in the close binaries. Alternatively, dynamical clearing of gaps by close binaries is marginally sufficient to lower their submillimeter fluxes to the observed levels, even without reduction of surface densities elsewhere in the disks.Comment: 12 pages, uuencoded compressed postscript with figures; Wisconsin Astrophysics 526; to appear in ApJ Letter

The Influence of Federal Laboratory R&D on Industrial Research

Over the past 60 years the United States has created the world's largest system of government laboratories. The impact of the laboratories on the private economy has been little studied though their research accounts for 14% of total U.S. R&D, more than the R&D of all colleges and universities combined. In this paper we study the influence of federal laboratory R&D on industrial research using a sample of industrial laboratories. In head-to-head comparisons with alternative measures, we find that Cooperative Research and Development Agreements or CRADAs, are the primary channel by which federal laboratories increase the patenting and R&D of industrial laboratories. With a CRADA industrial laboratories patent more, spend more on company-financed R&D and spend more of their own money on federal laboratories. Without a CRADA patenting stays about the same and only federally funded R&D increases, mostly because of direct subsidies by government. These results are consistent with the literature on endogenous R&D spillovers, which emphasizes that knowledge spills over when recipients work at making it spill over. CRADAs are legal agreements between federal laboratories and firms to work together on joint research. They are backed by real budgets and accompanied by cost sharing that could bind the parties together in joint research. Moreover, the CRADA instrument is the main form of such agreements. Thus, both in theory and in fact CRADAs may be more beneficial to firms than other public- private interactions, precisely because of the mutual effort that they require of firms and government laboratories.

The Influence of Federal Laboratory R&D on Industrial Research

This paper studies the influence of R&D in the federal laboratory system, the world's largest, on firm research. Our results are based on a sample of 220 industrial research laboratories that work with a variety of federal laboratories and agencies and are owned by 115 firms in the chemicals, machinery, electrical equipment, and motor vehicles industries. Using an indicator of their importance to R&D managers, we find that Cooperative Research and Development Agreements or CRADAs dominate other channels of technology transfer from federal laboratories to firms. With a CRADA industry laboratories patent more, spend more on company-financed R&D, and devote more resources to their federal counterparts. Without this influence patenting stays about the same, and only federally funded R&D increases, mostly because of government support. The Stevenson-Wydler Act and amendments during the 1980s introduced CRADAs, which legally bind federal laboratories and firms together in joint research. In theory the agreements could capitalize on complementarities between public and private research. Our results support this perspective and suggest that CRADAs may be more beneficial to firms than other interactions with federal laboratories, precisely because of the mutual effort that they demand from both parties.

Young Binary Stars and Associated Disks

The typical product of the star formation process is a binary star. Binaries have provided the first dynamical measures of the masses of pre-main-sequence (PMS) stars, providing support for the calibrations of PMS evolutionary tracks. Surprisingly, in some star-forming regions PMS binary frequencies are higher than among main-sequence solar-type stars. The difference in PMS and main-sequence binary frequencies is apparently not an evolutionary effect; recent attention has focussed on correlations between binary frequency and stellar density or cloud temperatures. Accretion disks are common among young binary stars. Binaries with separations between 1 AU and 100 AU have substantially less submillimeter emission than closer or wider binaries, suggesting that they have truncated their disks. Evidence of dynamical clearing has been seen in several binaries. Remarkably, PMS binaries of all separations show evidence of circumstellar disks and continued accretion. This suggests that the circumstellar disks are replenished from circumbinary disks or envelopes. The frequent presence of disks suggests that planet formation can occur in binary environments, and formation of planets in wide binaries is already established by their discovery. Circumbinary disk masses around very short period binaries are ample to form planetary systems such as our own. The nature of planetary systems among the most common binaries, with separations between 10 AU and 100 AU, is less clear given the observed reduction in disk mass, though they may have disk masses adequate for the formation of terrestrial-like planets.Comment: 32 pages, including 6 Postscript figures (TeX, uses psfig.sty); to appear in "Protostars & Planets IV". Gif figures with captions and high-res Postscript color figure available at http://hven.swarthmore.edu/~jensen/preprints/ppiv.htm

Misaligned Protoplanetary Disks In A Young Binary Star System

Many extrasolar planets follow orbits that differ from the nearly coplanar and circular orbits found in our Solar System; their orbits may be eccentric or inclined with respect to the host star\u27s equator, and the population of giant planets orbiting close to their host stars suggests appreciable orbital migration. There is at present no consensus on what produces such orbits. Theoretical explanations often invoke interactions with a binary companion star in an orbit that is inclined relative to the planet\u27s orbital plane. Such mechanisms require significant mutual inclinations between the planetary and binary star orbital planes. The protoplanetary disks in a few young binaries are misaligned, but often the measurements of these misalignments are sensitive only to a small portion of the inner disk, and the three-dimensional misalignment of the bulk of the planet-forming disk mass has hitherto not been determined. Here we report that the protoplanetary disks in the young binary system HK Tauri are misaligned by 60 to 68 degrees, such that one or both of the disks are significantly inclined to the binary orbital plane. Our results demonstrate that the necessary conditions exist for misalignment-driven mechanisms to modify planetary orbits, and that these conditions are present at the time of planet formation, apparently because of the binary formation process