Human factors evaluation of the Auxiliary Hot Cell Facility, Sandia National Laboratories, Albuquerque, New Mexico.

The Auxiliary Hot Cell Facility (AHCF) at Sandia National Laboratories, New Mexico (SNL/NM) is a Hazard Category 3 nuclear facility used to characterize, treat, and repackage radioactive and mixed material for reuse, recycling, or ultimate disposal. Mixed waste may also be handled at the AHCF. A significant upgrade to a previous facility, the Temporary Hot Cell, was required to perform this mission. A checklist procedure was used to perform a human-factors evaluation of the AHCF modifications. This evaluation resulted in two recommendations, both of which have been implemented

In-the-Gap SU UMa-Type Dwarf Nova, Var73 Dra with a Supercycle of about 60 Days

An intensive photometric-observation campaign of the recently discovered SU UMa-type dwarf nova, Var73 Dra was conducted from 2002 August to 2003 February. We caught three superoutbursts in 2002 October, December and 2003 February. The recurrence cycle of the superoutburst (supercycle) is indicated to be $\sim$60 d, the shortest among the values known so far in SU UMa stars and close to those of ER UMa stars. The superhump periods measured during the first two superoutbursts were 0.104885(93) d, and 0.10623(16) d, respectively. A 0.10424(3)-d periodicity was detected in quiescence. The change rate of the superhump period during the second superoutburst was $1.7\times10^{-3}$, which is an order of magnitude larger than the largest value ever known. Outburst activity has changed from a phase of frequent normal outbursts and infrequent superoutbursts in 2001 to a phase of infrequent normal outbursts and frequent superoutbursts in 2002. Our observations are negative to an idea that this star is an related object to ER UMa stars in terms of the duty cycle of the superoutburst and the recurrence cycle of the normal outburst. However, to trace the superhump evolution throughout a superoutburst, and from quiescence more effectively, may give a fruitful result on this matter.Comment: 9 pages, 8 figures, submitted to A&

Superhumps in Cataclysmic Binaries. XXIII. V442 Ophiuchi and RX J1643.7+3402

We report the results of long observing campaigns on two novalike variables: V442 Ophiuchi and RX J1643.7+3402. These stars have high-excitation spectra, complex line profiles signifying mass loss at particular orbital phases, and similar orbital periods (respectively 0.12433 and 0.12056 d). They are well-credentialed members of the SW Sex class of cataclysmic variables. Their light curves are also quite complex. V442 Oph shows periodic signals with periods of 0.12090(8) and 4.37(15) days, and RX J1643.7+3402 shows similar signals at 0.11696(8) d and 4.05(12) d. We interpret these short and long periods respectively as a "negative superhump" and the wobble period of the accretion disk. The superhump could then possibly arise from the heating of the secondary (and structures fixed in the orbital frame) by inner-disk radiation, which reaches the secondary relatively unimpeded since the disk is not coplanar. At higher frequencies, both stars show another type of variability: quasi-periodic oscillations (QPOs) with a period near 1000 seconds. Underlying these strong signals of low stability may be weak signals of higher stability. Similar QPOs, and negative superhumps, are quite common features in SW Sex stars. Both can in principle be explained by ascribing strong magnetism to the white dwarf member of the binary; and we suggest that SW Sex stars are borderline AM Herculis binaries, usually drowned by a high accretion rate. This would provide an ancestor channel for AM Hers, whose origin is still mysterious.Comment: PDF, 41 pages, 4 tables, 16 figures; accepted, in press, to appear December 2002, PASP; more info at http://cba.phys.columbia.edu

A model of superoutbursts in binaries of SU UMa type

A new mechanism explaining superoutbursts in binaries of SU UMa type is proposed. In the framework of this mechanism the accretion rate increase leading to the superoutburst is associated with formation of a spiral wave of a new "precessional" type in inner gasdynamically unperturbed parts of the accretion disc. The possibility of existence of this type of waves was suggested in our previous work (astro-ph/0403053). The features of the "precessional" spiral wave allow explaining both the energy release during the outburst and all its observational manifestations. The distinctive characteristic of a superoutburst in a SU UMa type star is the appearance of the superhump on the light curve. The proposed model reproduces well the formation of the superhump as well as its observational features, such as the period that is 3-7% longer than the orbital one and the detectability of superhumps regardless of the binary inclination.Comment: LaTeX, 20 pages, 4 figures, to be published in Astron. Z

Discovery of a Second Transient Low-Mass X-ray Binary in the Globular Cluster NGC 6440

We have identified a new transient luminous low-mass X-ray binary, NGC 6440 X-2, with Chandra/ACIS, RXTE/PCA, and Swift/XRT observations of the globular cluster NGC 6440. The discovery outburst (July 28-31, 2009) peaked at L_X~1.5*10^36 ergs/s, and lasted for <4 days above L_X=10^35 ergs/s. Four other outbursts (May 29-June 4, Aug. 29-Sept. 1, Oct. 1-3, and Oct. 28-31 2009) have been observed with RXTE/PCA (identifying millisecond pulsations, Altamirano et al. 2009a) and Swift/XRT (confirming a positional association with NGC 6440 X-2), with similar peak luminosities and decay times. Optical and infrared imaging did not detect a clear counterpart, with best limits of V>21, B>22 in quiescence from archival HST imaging, g'>22 during the August outburst from Gemini-South GMOS imaging, and J>~18.5$ and K>~17 during the July outburst from CTIO 4-m ISPI imaging. Archival Chandra X-ray images of the core do not detect the quiescent counterpart, and place a bolometric luminosity limit of L_{NS}< 6*10^31 ergs/s (one of the lowest measured) for a hydrogen atmosphere neutron star. A short Chandra observation 10 days into quiescence found two photons at NGC 6440 X-2's position, suggesting enhanced quiescent emission at L_X~6*10^31 ergs/s . NGC 6440 X-2 currently shows the shortest recurrence time (~31 days) of any known X-ray transient, although regular outbursts were not visible in the bulge scans before early 2009. Fast, low-luminosity transients like NGC 6440 X-2 may be easily missed by current X-ray monitoring.Comment: 13 pages (emulateapj), 8 (color) figures, ApJ in press. Revised version adds 5th outburst (Oct./Nov. 2009), additional discussion of possible causes of short outburst recurrence time

Extending the Climate Data Initiative to GeoPlatform.gov

No abstract availabl

Tumor Antigen Acrosin Binding Protein Normalizes Mitotic Spindle Function to Promote Cancer Cell Proliferation

Cancer cells manage to divide in the context of gross chromosomal abnormalities. These abnormalities can promote bypass of normal restraints on cell proliferation, but at a cost of mitotic vulnerabilities that can be attacked by chemotherapy. Determining how cancer cells balance these issues may permit chemotherapeutic sensitivity to be leveraged more efficiently. From a pan-genomic siRNA screen for modifiers of chemoresponsiveness, we identified the tumor antigen ACRBP/OY-TES-1 as a specifier of paclitaxel resistance. ACRBP expression is normally restricted to the testes but detected in a wide variety of cancers, including most ovarian cancers. We found that ACRBP is both necessary and sufficient for paclitaxel resistance in ovarian cancer cell lines and ovarian tumor explants. Moreover, high ACRBP expression correlated with reduced survival time and faster relapse among ovarian cancer patients. We identified the mitotic spindle protein NuMA as an ACRBP-interacting protein that could account for the effects of ACRBP on paclitaxel sensitivity. In cancer cells, ACRBP restricted a NuMA-dependent abrogation of mitotic spindle assembly that is otherwise pathologic. As a consequence, ACRBP depletion resulted in mitotic errors and reduced proliferative fitness that could be rescued by NuMA co-depletion. We propose that the co-dependent relationship of ACRBP and NuMA in cancer cells reflects their passage through a selection bottleneck during tumor evolution, one which requires the acquisition of traits which normalize mitotic perturbations that originally drove the plasticity of a pre-neoplastic genome. The molecular definition of such traits as defined by the ACRBP-NuMA complex may represent conceptually ideal intervention targets, based on the wide therapeutic windows they may offer

Early predictors of language and social communication impairments at ages 9-11 years: A follow-up study of early-referred children

Purpose: In this study, the authors aimed to evaluate hypotheses that early sociocognition will predict later social communication and early phonology will predict later morphosyntax in clinically referred preschoolers. Method: Participants were 108 children ages 9–11 years who had been referred to clinical services with concerns about language at age 2½–3½ years. Predictors at Time 1 (T1) were measures of sociocognition, word/nonword repetition, and receptive language. Outcome measures at Time 3 (T3) included a social communication questionnaire completed by parents and tests of nonword repetition, morphosyntax, and receptive language. Results: Group- and case-level analyses revealed early sociocognition to be the strongest predictor of social communication problems, which by T3 affected almost one third of the sample. At the group level, early phonology, which was a significant problem for the majority of children at T1, was a weak predictor of morphosyntax at T3. However, at the case level the majority of children with poor morphosyntax and nonword repetition at outcome had had very low repetition scores at T1. Conclusions: In early language referrals, it is important to identify and address sociocognitive problems, a considerable risk for later social communication and autism spectrum disorders. The majority of early-referred children had phonological problems, often severe, but these require further investigation to determine their longer term significance for language

GU81, a VEGFR2 antagonist peptoid, enhances the anti-tumor activity of doxorubicin in the murine MMTV-PyMT transgenic model of breast cancer

<p>Abstract</p> <p>Background</p> <p>Vascular endothelial growth factor (VEGF) is a primary stimulant of angiogenesis under physiological and pathological conditions. Anti-VEGF therapy is a clinically proven strategy for the treatment of a variety of cancers including colon, breast, lung, and renal cell carcinoma. Since VEGFR2 is the dominant angiogenic signaling receptor, it has become an important target in the development of novel anti-angiogenic therapies. We have reported previously the development of an antagonistic VEGFR2 peptoid (GU40C4) that has promising anti-angiogenic activity <it>in vitro </it>and <it>in vivo</it>.</p> <p>Methods</p> <p>In the current study, we utilize a derivative of GU40C4, termed GU81 in therapy studies. GU81 was tested alone or in combination with doxorubicin for <it>in vivo </it>efficacy in the MMTV-PyMT transgenic model of breast cancer.</p> <p>Results</p> <p>The derivative GU81 has increased <it>in vitro </it>efficacy compared to GU40C4. Single agent therapy (doxorubicin or GU81 alone) had no effect on tumor weight, histology, tumor fat content, or tumor growth index. However, GU81 is able to significantly to reduce total vascular area as a single agent. GU81 used in combination with doxorubicin significantly reduced tumor weight and growth index compared to all other treatment groups. Furthermore, treatment with combination therapy significantly arrested tumor progression at the premalignant stage, resulting in increased tumor fat content. Interestingly, treatment with GU81 alone increased tumor-VEGF levels and macrophage infiltration, an effect that was abrogated when used in combination with doxorubicin.</p> <p>Conclusion</p> <p>This study demonstrates the VEGFR2 antagonist peptoid, GU81, enhances the anti-tumor activity of doxorubicin in spontaneous murine MMTV-PyMT breast tumors.</p

The Importance of Consistent Global Forest Aboveground Biomass Product Validation

Several upcoming satellite missions have core science requirements to produce data for accurate forest aboveground biomass mapping. Largely because of these mission datasets, the number of available biomass products is expected to greatly increase over the coming decade. Despite the recognized importance of biomass mapping for a wide range of science, policy and management applications, there remains no community accepted standard for satellite-based biomass map validation. The Committee on Earth Observing Satellites (CEOS) is developing a protocol to fill this need in advance of the next generation of biomass-relevant satellites, and this paper presents a review of biomass validation practices from a CEOS perspective. We outline the wide range of anticipated user requirements for product accuracy assessment and provide recommendations for the validation of biomass products. These recommendations include the collection of new, high-quality in situ data and the use of airborne lidar biomass maps as tools toward transparent multi-resolution validation. Adoption of community-vetted validation standards and practices will facilitate the uptake of the next generation of biomass products