Computer program for Video Data Processing System /VDPS/

Video data from spacecraft photographic mission telemetry is scanned to generate digital tape computer program which prints out intensity points, cleans noise and telemetry drop-out, enhances contrast, modifies the picture, and calculates contour lines. The output is converted into new photographic film

V-like formations in flocks of artificial birds

We consider flocks of artificial birds and study the emergence of V-like formations during flight. We introduce a small set of fully distributed positioning rules to guide the birds' movements and demonstrate, by means of simulations, that they tend to lead to stabilization into several of the well-known V-like formations that have been observed in nature. We also provide quantitative indicators that we believe are closely related to achieving V-like formations, and study their behavior over a large set of independent simulations

Gaussian Post-selection for Continuous Variable Quantum Cryptography

We extend the security proof for continuous variable quantum key distribution protocols using post selection to account for arbitrary eavesdropping attacks by employing the concept of an equivalent protocol where the post-selection is implemented as a series of quantum operations including a virtual distillation. We introduce a particular `Gaussian' post selection and demonstrate that the security can be calculated using only experimentally accessible quantities. Finally we explicitly evaluate the performance for the case of a noisy Gaussian channel in the limit of unbounded key length and find improvements over all pre-existing continuous variable protocols in realistic regimes.Comment: 4+4 pages. arXiv admin note: substantial text overlap with arXiv:1106.082

Cost-benefit Analysis of a Genetic Marker on Cow-calf Operations Differentiated by Pasture and Breed

Genetic sequencing in beef cattle (Bos taurus L.) is expected to aid producers with selecting breeding stock. Using data from experimental trials conducted with Angus, Brahman, and their reciprocal cross, the single nucleotide polymorphism (SNP) P450 C994G marker expression was investigated for use in selecting genetics suited to grazing endophyte-infected tall fescue (Festuca arundinacea Schreb. L.) compared to bermudagrass (Cynodon dactylon L.) pasture. The study is unique in the sense that actual cow-calf breeding failure rates (open cows were not culled) were tracked from 1991 to 1997 on herds that were bred to calf in spring and were either exposed to fungal endophyte-infected (Acremonium coenophialum L.) tall fescue grazing and hay or not. The study used the Forage and Cattle Analysis and Planning (FORCAP) decision support software to assess economic performance driven by birth weight, weaning weight, and breeding failure rate differences across treatment. Results suggest that for reciprocal cross herds primarily grazing bermudagrass pastures, the P450 C994C genotype (CC) was most favorable; whereas, the P450 G994C genotype (GC) was more profitable with tall fescue. Adding genetic market information when selecting a production strategy led to approximately $15/head in added profitability. In comparison to the prorated cost of$2.40/head over the life of a dam, the collection, interpretation, and management of genetic information under the conditions observed in this study may be worthwhile

Defect-Seeded Atomic Layer Deposition of Metal Oxides on the Basal Plane of 2D Layered Materials

Atomic layer deposition (ALD) on mechanically exfoliated 2D layered materials spontaneously produces network patterns of metal oxide nanoparticles in triangular and linear deposits on the basal surface. The network patterns formed under a range of ALD conditions and were independent of the orientation of the substrate in the ALD reactor. The patterns were produced on MoS2 or HOPG when either tetrakis(dimethylamido)titanium or bis(ethylcyclopentadienyl)manganese were used as precursors, suggesting that the phenomenon is general for 2D materials. Transmission electron microscopy revealed the presence, prior to deposition, of dislocation networks along the basal plane of mechanically exfoliated 2D flakes, indicating that periodical basal plane defects related to disruptions in the van der Waals stacking of layers, such as perfect line dislocations and triangular extended stacking faults networks, introduce a surface reactivity landscape that leads to the emergence of patterned deposition

N-methylation of a bactericidal compound as a resistance mechanism in Mycobacterium tuberculosis

The rising incidence of antimicrobial resistance (AMR) makes it imperative to understand the underlying mechanisms. Mycobacterium tuberculosis (Mtb) is the single leading cause of death from a bacterial pathogen and estimated to be the leading cause of death from AMR. A pyrido-benzimidazole, 14, was reported to have potent bactericidal activity against Mtb. Here, we isolated multiple Mtb clones resistant to 14. Each had mutations in the putative DNA-binding and dimerization domains of rv2887, a gene encoding a transcriptional repressor of the MarR family. The mutations in Rv2887 led to markedly increased expression of rv0560c. We characterized Rv0560c as an S-adenosyl-L-methionine-dependent methyltransferase that N-methylates 14, abolishing its mycobactericidal activity. An Mtb strain lacking rv0560c became resistant to 14 by mutating decaprenylphosphoryl-beta-d-ribose 2-oxidase (DprE1), an essential enzyme in arabinogalactan synthesis; 14 proved to be a nanomolar inhibitor of DprE1, and methylation of 14 by Rv0560c abrogated this activity. Thus, 14 joins a growing list of DprE1 inhibitors that are potently mycobactericidal. Bacterial methylation of an antibacterial agent, 14, catalyzed by Rv0560c of Mtb, is a previously unreported mechanism of AMR

Limited Activity Of Miltefosine In Murine Models Of Cryptococcal Meningoencephalitis And Disseminated Cryptococcosis

Miltefosine is an alkyl phosphocholine with good oral bioavailability and in vitro activity against Cryptococcus species that has gained interest as an additional agent for cryptococcal infections. Our objective was to further evaluate the in vivo efficacy of miltefosine in experimental in vivo models of cryptococcal meningoencephalitis and disseminated cryptococcosis. Mice were infected intracranially or intravenously with either C. neoformans USC1597 or H99. Miltefosine treatment (1.8 to 45 mg/kg of body weight orally once daily) began at either 1 h or 1 day postinoculation. Fluconazole (10 mg/kg orally twice daily) or amphotericin B deoxycholate (3 mg/kg intraperitoneally once daily) served as positive controls. In our standard models, miltefosine did not result in significant improvements in survival or reductions in fungal burden against either C. neoformans isolate. There was a trend toward improved survival with miltefosine at 7.2 mg/kg against disseminated cryptococcosis with the H99 strain but only at a low infecting inoculum. In contrast, both fluconazole and amphotericin B significantly improved survival in mice with cryptococcal meningoencephalitis and disseminated cryptococcosis due to USC1597. Amphotericin B also improved survival against both cryptococcal infections caused by H99. Combination therapy with miltefosine demonstrated neither synergy nor antagonism in both models. These results demonstrate limited efficacy of miltefosine and suggest caution with the potential use of this agent for the treatment of C. neoformans infections.Pharmac

Examination of Surface Temperature Modification by Open-Top Chambers along Moisture and Latitudinal Gradients in Arctic Alaska Using Thermal Infrared Photography

Passive warming manipulation methodologies, such as open-top chambers (OTCs), are a meaningful approach for interpretation of impacts of climate change on the Arctic tundra biome. The magnitude of OTC warming has been studied extensively, revealing an average plot-level warming of air temperature that ranges between 1 and 3 °C as measured by shielded resistive sensors or thermocouples. Studies have also shown that the amount of OTC warming depends in part on location climate, vegetation, and soil properties. While digital infrared thermometers have been employed in a few comparisons, most of the focus of the effectiveness of OTC warming has been on air or soil temperature rather than tissue or surface temperatures, which directly translate to metabolism. Here we used thermal infrared (TIR) photography to quantify tissue and surface temperatures and their spatial variability at a previously unavailable resolution (3–6 mm2). We analyzed plots at three locations that are part of the International Tundra Experiment (ITEX)-Arctic Observing Network (AON-ITEX) network along both moisture and latitudinal gradients spanning from the High Arctic (Barrow, AK, USA) to the Low Arctic (Toolik Lake, AK, USA). Our results show a range of OTC surface warming from 2.65 to 1.27 °C (31%–10%) at our three sites. The magnitude of surface warming detected by TIR imagery in this study was comparable to increases in air temperatures previously reported for these sites. However, the thermal images revealed wide ranges of surface temperatures within the OTCs, with some surfaces well above ambient unevenly distributed within the plots under sunny conditions. We note that analyzing radiometric temperature may be an alternative for future studies that examine data acquired at the same time of day from sites that are in close geographic proximity to avoid the requirement of emissivity or atmospheric correction for validation of results. We foresee future studies using TIR photography to describe species-level thermodynamics that could prove highly valuable toward a better understanding of species-specific responses to climate change in the Arctic

Progressive Star Bursts and High Velocities in the Infrared Luminous, Colliding Galaxy Arp 118

In this paper we demonstrate for the first time the connection between the spatial and temporal progression of star formation and the changing locations of the very dense regions in the gas of a massive disk galaxy (NGC 1144) in the aftermath of its collision with a massive elliptical (NGC 1143). These two galaxies form the combined object Arp 118, a collisional ring galaxy system. The results of 3D, time-dependent, numerical simulations of the behavior of the gas, stars, and dark matter of a disk galaxy and the stars and dark matter in an elliptical during a collision are compared with multiwavelength observations of Arp 118. The collision that took place approximately 22 Myr ago generated a strong, non-linear density wave in the stars and gas in the disk of NGC 1144, causing the gas to became clumped on a large scale. This wave produced a series of superstarclusters along arcs and rings that emanate from the central point of impact in the disk. The locations of these star forming regions match those of the regions of increased gas density predicted the time sequence of models. The models also predict the large velocity gradients observed across the disk of NGC 1144. These are due to the rapid radial outflow of gas coupled to large azimuthal velocities in the expanding ring, caused by the impact of the massive intruder.Comment: 12 pages in document, and 8 figures (figures are separate from the document's file); Submitted to Astrophysical Journal Letter

The Origin and Universality of the Stellar Initial Mass Function

We review current theories for the origin of the Stellar Initial Mass Function (IMF) with particular focus on the extent to which the IMF can be considered universal across various environments. To place the issue in an observational context, we summarize the techniques used to determine the IMF for different stellar populations, the uncertainties affecting the results, and the evidence for systematic departures from universality under extreme circumstances. We next consider theories for the formation of prestellar cores by turbulent fragmentation and the possible impact of various thermal, hydrodynamic and magneto-hydrodynamic instabilities. We address the conversion of prestellar cores into stars and evaluate the roles played by different processes: competitive accretion, dynamical fragmentation, ejection and starvation, filament fragmentation and filamentary accretion flows, disk formation and fragmentation, critical scales imposed by thermodynamics, and magnetic braking. We present explanations for the characteristic shapes of the Present-Day Prestellar Core Mass Function and the IMF and consider what significance can be attached to their apparent similarity. Substantial computational advances have occurred in recent years, and we review the numerical simulations that have been performed to predict the IMF directly and discuss the influence of dynamics, time-dependent phenomena, and initial conditions.Comment: 24 pages, 6 figures. Accepted for publication as a chapter in Protostars and Planets VI, University of Arizona Press (2014), eds. H. Beuther, R. S. Klessen, C. P. Dullemond, Th. Hennin