Discovery of the Orbit of the Transient X ray Pulsar SAX J2103.5+4545

Using X-ray data from the Rossi X-Ray Timing Explorer (RXTE), we carried out pulse timing analysis of the transient X-ray pulsar SAX J2103.5+4545. An outburst was detected by All Sky Monitor (ASM) October 25 1999 and reached a peak X-ray brightness of 27 mCrab October 28. Between November 19 and December 27, the RXTE/PCA carried out pointed observations which provided us with pulse arrival times. These yield an eccentric orbit (e= 0.4 \pm 0.2) with an orbital period of 12.68 \pm 0.25 days and light travel time across the projected semimajor axis of 72 \pm 6 sec. The pulse period was measured to be 358.62171 \pm 0.00088 s and the spin-up rate (2.50 \pm 0.15) \times 10^{-13} Hz s^{-1}. The ASM data for the February to September 1997 outburst in which BeppoSAX discovered SAX J2103.5+4545 (Hulleman, in't Zand and Heise 1998) are modulated at time scales close to the orbital period. Folded light curves of the 1997 ASM data and the 1999 PCA data are similar and show that the intensity increases at periastron passages.Comment: To appear in The Astrophysical Journal (Letters

Phosphorylation of Sli15 by Ipl1 is important for proper CPC localization and chromosome stability in <em>Saccharomyces cerevisiae</em>

The chromosomal passenger complex (CPC) is a key regulator of eukaryotic cell division, consisting of the protein kinase Aurora B/Ipl1 in association with its activator (INCENP/Sli15) and two additional proteins (Survivin/Bir1 and Borealin/Nbl1). Here we have identified multiple sites of CPC autophosphorylation on yeast Sli15 that are located within its central microtubule-binding domain and examined the functional significance of their phosphorylation by Ipl1 through mutation of these sites, either to non-phosphorylatable alanine (sli15-20A) or to acidic residues to mimic constitutive phosphorylation (sli15-20D). Both mutant sli15 alleles confer chromosome instability, but this is mediated neither by changes in the capacity of Sli15 to activate Ipl1 kinase nor by decreased efficiency of chromosome biorientation, a key process in cell division that requires CPC function. Instead, we find that mimicking constitutive phosphorylation of Sli15 on the Ipl1 phosphorylation sites causes delocalization of the CPC in metaphase, whereas blocking phosphorylation of Sli15 on the Ipl1 sites drives excessive localization of Sli15 to the mitotic spindle in pre-anaphase cells. Consistent with these results, direct interaction of Sli15 with microtubules in vitro is greatly reduced either following phosphorylation by Ipl1 or when constitutive phosphorylation at the Ipl1-dependent phosphorylation sites is mimicked by aspartate or glutamate substitutions. Furthermore, we find that mimicking Ipl1 phosphorylation of Sli15 interferes with the 'tension checkpoint'--the CPC-dependent mechanism through which cells activate the spindle assembly checkpoint to delay anaphase in the absence of tension on kinetochore-microtubule attachments. Ipl1-dependent phosphorylation of Sli15 therefore inhibits its association with microtubules both in vivo and in vitro and may negatively regulate the tension checkpoint mechanism

ATLAST detector needs for direct spectroscopic biosignature characterization in the visible and near-IR

Are we alone? Answering this ageless question will be a major focus for astrophysics in coming decades. Our tools will include unprecedentedly large UV-Optical-IR space telescopes working with advanced coronagraphs and starshades. Yet, these facilities will not live up to their full potential without better detectors than we have today. To inform detector development, this paper provides an overview of visible and near-IR (VISIR; $\lambda=0.4-1.8~\mu\textrm{m}$) detector needs for the Advanced Technology Large Aperture Space Telescope (ATLAST), specifically for spectroscopic characterization of atmospheric biosignature gasses. We also provide a brief status update on some promising detector technologies for meeting these needs in the context of a passively cooled ATLAST.Comment: 8 pages, Presented 9 August 2015 at SPIE Optics + Photonics, San Diego, C

A Functional Link Between Bir1 and the <i>Saccharomyces cerevisiae</i> Ctf19 Kinetochore Complex Revealed Through Quantitative Fitness Analysis

The chromosomal passenger complex (CPC) is a key regulator of eukaryotic cell division, consisting of the protein kinase Aurora B/Ipl1 in association with its activator (INCENP/Sli15) and two additional proteins (Survivin/Bir1 and Borealin/Nbl1). Here, we report a genome-wide genetic interaction screen in Saccharomyces cerevisiae using the bir1-17 mutant, identifying through quantitative fitness analysis deletion mutations that act as enhancers and suppressors. Gene knockouts affecting the Ctf19 kinetochore complex were identified as the strongest enhancers of bir1-17, while mutations affecting the large ribosomal subunit or the mRNA nonsense-mediated decay pathway caused strong phenotypic suppression. Thus, cells lacking a functional Ctf19 complex become highly dependent on Bir1 function and vice versa. The negative genetic interaction profiles of bir1-17 and the cohesin mutant mcd1-1 showed considerable overlap, underlining the strong functional connection between sister chromatid cohesion and chromosome biorientation. Loss of some Ctf19 components, such as Iml3 or Chl4, impacted differentially on bir1-17 compared with mutations affecting other CPC components: despite the synthetic lethality shown by either iml3∆ or chl4∆ in combination with bir1-17, neither gene knockout showed any genetic interaction with either ipl1-321 or sli15-3. Our data therefore imply a specific functional connection between the Ctf19 complex and Bir1 that is not shared with Ipl1

Missouri National Recreational River, Natural Resource Condition Assessment

Executive Summary As a unit in the National Park Service (NPS), Missouri National Recreational River (MNRR) is responsible for the management and conservation of natural resources within its boundaries. This mandate is supported by the National Park Service Organic Act of 1916, which directs the NPS to: conserve the scenery and natural and historic objects and the wildlife therein and to provide for the enjoyment of the same in such a manner and by such means as will leave them unimpaired for the enjoyment of future generations. In 2003, NPS Water Resources Division received funding through the Natural Resource Challenge Program to systematically assess watershed resource conditions in NPS units, establishing the Watershed Condition Assessment Program. This program, now titled the Natural Resource Condition Assessment (NRCA) Program, aims to provide documentation about the current conditions of important park resources through a spatially explicit, multi-disciplinary synthesis of existing scientific data and knowledge. Findings from the NRCA, including the report and accompanying map products, will help MNRR managers to: develop near-term management priorities, engage in watershed or landscape scale partnership and education efforts, conduct park planning (e.g. Resource Stewardship Strategy), report program performance (e.g. Department of the Interior’s Strategic Plan ―land health goals, Government Performance and Results Act). Specific project expectations and outcomes for the MNRR NRCA are listed in Chapter 3. For the purpose of this NRCA, NPS staff identified key resources that are referred to as ―components‖ in the project framework and throughout the assessment. The components selected include natural resources and processes that are currently of the greatest concern to park management at MNRR. The final project framework contains nine resource components, along with measures, stressors, and reference conditions for each. This study involved reviewing existing literature and data for each of the components in the framework and, where appropriate, analyzing the data in order to provide summaries or to create new spatial or statistical representations. After gathering data regarding current condition of component measures, those data were compared to reference conditions (when possible) and a qualitative statement of condition was developed. The discussions in Chapter 4 represent a comprehensive summary of available information regarding the current condition of these resources. These discussions represent not only the most current published literature, but also unpublished park information and, most importantly, the perspectives of park experts. Nearly every component in MNRR is affected by the altered flow regime from the post-dam Missouri River and, with that, the conditions of most park resources (as indicated by the measures defined in the project framework) are of moderate or significant concern. These condition designations are largely a product of the ―pre-dam‖ reference condition assigned to nearly every MNRR component. When comparing the current condition of a resource that has been drastically altered by damming to its pre-dam condition, it is almost always worse off today. However, while the Missouri River ecosystem has endured large changes since dam construction, there are several individual components that are recovering and doing well with the given circumstances. Differing uses and interests of the Missouri River (e.g. preservation, recreation, electricity generation, navigation, etc.) further complicate MNRR’s ability to restore the Missouri River to its pre-dam condition. However, several components ( e.g. flow regime, aquatic and terrestrial habitats, erosional and depositional processes) are drivers of the entire ecosystem, and restoration of these components would have a cascading effect on the entire ecosystem. Overall, the Missouri River ecosystem is complex and while several components are considered to be of moderate or significant concern, their actual condition (when considering the the condition of the Missouri River ecosystem) is often times of lower concern

Shadow of a Colossus: A z=2.45 Galaxy Protocluster Detected in 3D Ly-a Forest Tomographic Mapping of the COSMOS Field

Using moderate-resolution optical spectra from 58 background Lyman-break galaxies and quasars at $z\sim 2.3-3$ within a $11.5'\times13.5'$ area of the COSMOS field ($\sim 1200\,\mathrm{deg}^2$ projected area density or $\sim 2.4\,h^{-1}\,\mathrm{Mpc}$ mean transverse separation), we reconstruct a 3D tomographic map of the foreground Ly$\alpha$ forest absorption at $2.2<z<2.5$ with an effective smoothing scale of $\sigma_{3d}\approx3.5\,h^{-1}\,\mathrm{Mpc}$ comoving. Comparing with 61 coeval galaxies with spectroscopic redshifts in the same volume, we find that the galaxy positions are clearly biased towards regions with enhanced IGM absorption in the tomographic map. We find an extended IGM overdensity with deep absorption troughs at $z=2.45$ associated with a recently-discovered galaxy protocluster at the same redshift. Based on simulations matched to our data, we estimate the enclosed dark matter mass within this IGM overdensity to be $M_{\rm dm} (z=2.45) = (9\pm4)\times 10^{13}\,h^{-1}\,\mathrm{M_\odot}$, and argue based on this mass and absorption strength that it will form at least one $z\sim0$ galaxy cluster with $M(z=0) = (3\pm 2) \times 10^{14}\,h^{-1}\mathrm{M_\odot}$, although its elongated nature suggests that it will likely collapse into two separate clusters. We also point out a compact overdensity of six MOSDEF galaxies at $z=2.30$ within a $r\sim 1\,h^{-1}\,\mathrm{Mpc}$ radius and $\Delta z\sim 0.006$, which does not appear to have a large associated IGM overdensity. These results demonstrate the potential of Ly$\alpha$ forest tomography on larger volumes to study galaxy properties as a function of environment, as well as revealing the large-scale IGM overdensities associated with protoclusters and other features of large-scale structure.Comment: To be submitted to ApJ. Figure 3 can be viewed on Youtube: https://youtu.be/KeW1UJOPMY

A Search for Exozodiacal Clouds with Kepler

Planets embedded within dust disks may drive the formation of large scale clumpy dust structures by trapping dust into resonant orbits. Detection and subsequent modeling of the dust structures would help constrain the mass and orbit of the planet and the disk architecture, give clues to the history of the planetary system, and provide a statistical estimate of disk asymmetry for future exoEarth-imaging missions. Here we present the first search for these resonant structures in the inner regions of planetary systems by analyzing the light curves of hot Jupiter planetary candidates identified by the Kepler mission. We detect only one candidate disk structure associated with KOI 838.01 at the 3-sigma confidence level, but subsequent radial velocity measurements reveal that KOI 838.01 is a grazing eclipsing binary and the candidate disk structure is a false positive. Using our null result, we place an upper limit on the frequency of dense exozodi structures created by hot Jupiters. We find that at the 90% confidence level, less than 21% of Kepler hot Jupiters create resonant dust clumps that lead and trail the planet by ~90 degrees with optical depths >~5*10^-6, which corresponds to the resonant structure expected for a lone hot Jupiter perturbing a dynamically cold dust disk 50 times as dense as the zodiacal cloud.Comment: 22 pages, 6 figures, Accepted for publication in Ap

Stability of commercial phytase products under increasing thermal conditioning temperatures

Citation: De Jong, J. A., DeRouchey, J. M., Tokach, M. D., Goodband, R. D., Woodworth, J. C., Jones, C. K., . . . Bergstrom, J. R. (2016). Stability of commercial phytase products under increasing thermal conditioning temperatures. Journal of Animal Science, 94, 101-101. doi:10.2527/msasas2016-214The objective was to determine the stability of 4 commercial phytase products exposed to increasing thermal conditioning temperatures. The 4 commercial products used were: Quantum Blue 5G (AB Vista, Marlborough, United Kingdom); Ronozyme Hi Phos GT (DSM Nutritional Products, Parsippany, NJ); Axtra Phy TPT (Dupont, Wilmington, DE), and Microtech 5000 Plus (Guangdong VTR Bio-Tech Co., Ltd., Guangdong, China). The phytase products were mixed as part of a corn-soybean meal-based swine diet at a concentration recommended by the manufacturer to provide a 0.12% aP release. Diets were exposed to each of 4 thermal conditioning temperatures (65, 75, 85, and 95°C) for approximately 40 s and the entire process was repeated on 4 consecutive days to create 4 replicates. Samples were taken while feed exited the conditioner and before entering the pellet die. Phytase activity was determined from complete feed samples before conditioning to establish a baseline diet phytase activity level for each product. Phytase stability was measured as the residual phytase activity (% of initial) at each conditioning temperature. There were no product × temperature interactions for conditioning temperature, throughput, or residual phytase activity. As expected, as the target temperature was increased, conditioning temperature increased (linear, P < 0.001) and conditioner throughput decreased (linear, P < 0.001). As target temperature increased, phytase activity decreased (linear, P < 0.001) for each product. There was a significant phytase product main effect which was primarily caused by Microtech 5000 Plus having decreased (P < 0.05) phytase activity when compared to all other products at all conditioning temperatures. In summary, increasing conditioning temperatures decreased phytase stability regardless of product. In addition, Microtech 5000 Plus had decreased residual phytase activity (% of initial) when compared to all other products

Stability of commercial phytase products stored under different environmental conditions

Citation: De Jong, J. A., DeRouchey, J. M., Tokach, M. D., Goodband, R. D., Woodworth, J. C., Jones, C. K., . . . Bergstrom, J. R. (2016). Stability of commercial phytase products stored under different environmental conditions. Journal of Animal Science, 94, 114-114. doi:10.2527/msasas2016-241A 300-d study evaluated the stability of 4 phytase products stored under varied environmental conditions. The 4 products were: 1) Quantum Blue 5G (AB Vista, Marlborough, United Kingdom); 2) Ronozyme HiPhos GT 2700 (DSM Nutritional Products, Parsippany, NJ); 3) Axtra Phy TPT (Dupont, Wilmington, DE); and 4) Microtech 5000 Plus (Guangdong VTR Bio-Tech Co., Ltd., Guangdong, China). Products were stored as pure forms at ?20, 4, 22, or 35°C (75% humidity), or in a vitamin or vitamin trace mineral (VTM) premix at 22 and 35°C (75% humidity). Samples were stored in paper bags and sampled on d 30, 60, 90, 120, 210, and 300. Stability was determined as amount of residual phytase activity (% of initial). For pure forms, all interactive and main effects of product, time, and temperature were significant (P < 0.05). From d 30 to 300, products had similar reductions in phytase activity at the 3 highest temperatures; however, Quantum Blue 5G, Ronozyme HiPhos GT 2700, and Axtra Phy TPT had reduced (P < 0.05) phytase activity compared to Microtech 5000 Plus at ?20°C. As storage time increased, residual phytase activity was reduced (P < 0.05) regardless of product and storage temperature. Also, when product was stored at 4 and 22°C, phytase activity was improved compared to ?20 and 35°C. For vitamin and VTM premixes, a time×temperature × product interaction (P < 0.05) was observed as a result of, Axtra Phy TPT and Microtech 5000 Plus having reduced residual phytase activity (P < 0.05) compared to the other 2 products when stored at 22°C, while activity of Axtra Phy TPT was reduced (P < 0.05) even further than the other 3 products when stored at 35°C regardless of form. From d 30 to 300, Axtra Phy TPT and Microtech 5000 Plus had the lowest (P < 0.05) residual phytase activity compared to the other 2 products. The VTM had decreased (P < 0.05) residual phytase activity compared to the pure product and vitamin premixes. In conclusion, phytase stored for longer than 90–120 d at 35°C or ?20°C in pure form, or when stored as a VTM premix had reduced residual phytase activity

Water Absorption From Line-of-Sight Clouds Toward W49A

We have observed 6 clouds along the line-of-sight toward W49A using the Submillimeter Wave Astronomy Satellite (SWAS) and several ground-based observatories. The ortho-H2O 1-0 and OH (1665 and 1667 MHz) transitions are observed in absorption, whereas the low-J CO, 13CO, and C18O lines, as well as the [CI] 1-0 transition, are seen in emission. By using both the o-H218O and o-H2O absorption lines, we are able to constrain the column-averaged o-H_2O abundances in each line-of-sight cloud to within about an order of magnitude. Assuming the standard N(H2)/N(CO) ratio of 10^4, we find N(o-H2O)/N(H2) = 8.1 x 10^-8 - 4 x 10^-7 for three clouds with optically thin water lines. In three additional clouds, the H$_2$O lines are saturated so we have used observations of the H218O ground-state transition to find upper limits to the water abundance of 8.2x 10^-8 - 1.5x10^-6. We measure the OH abundance from the average of the 1665 and 1667 MHz observations and find N(OH)/N(H2) = 2.3x10^-7 - 1.1x10^-6. The o-H2O and OH abundances are similar to those determined for line-of-sight water absorption features towards W51 and Sgr B2 but are higher than those seen from water emission lines in molecular clouds. However, the clouds towards W49 have lower ratios of OH relative to H2O column densities than are predicted by simple models which assume that dissociative recombination is the primary formation pathway for OH and H2O. Building on the work of Neufeld et al. (2002), we present photo-chemistry models including additional chemical effects, which can also explain the observed OH and H2O column densities as well as the observed H2O/CO abundance ratios.Comment: 32 pages, 7 figures, To appear in ApJ April 10 issu