A strongly goal-directed close-range vision system for spacecraft docking

In this presentation, we will propose a strongly goal-oriented stereo vision system to establish proper docking approach motions for automated rendezvous and capture (AR&C). From an input sequence of stereo video image pairs, the system produces a current best estimate of: contact position; contact vector; contact velocity; and contact orientation. The processing demands imposed by this particular problem and its environment dictate a special case solution; such a system should necessarily be, in some sense, minimalist. By this we mean the system should construct a scene description just sufficiently rich to solve the problem at hand and should do no more processing than is absolutely necessary. In addition, the imaging resolution should be just sufficient. Extracting additional information and constructing higher level scene representations wastes energy and computational resources and injects an unnecessary degree of complexity, increasing the likelihood of malfunction. We therefore take a departure from most prior stereopsis work, including our own, and propose a system based on associative memory. The purpose of the memory is to immediately associate a set of motor commands with a set of input visual patterns in the two cameras. That is, rather than explicitly computing point correspondences and object positions in world coordinates and trying to reason forward from this information to a plan of action, we are trying to capture the essence of reflex behavior through the action of associative memory. The explicit construction of point correspondences and 3D scene descriptions, followed by online velocity and point of impact calculations, is prohibitively expensive from a computational point of view for the problem at hand. Learned patterns on the four image planes, left and right at two discrete but closely spaced instants in time, will be bused directly to infer the spacecraft reaction. This will be a continuing online process as the docking collar approaches

Note and Comment

The Permanent International Court of Justice - For the first time in history leading powers both great and small have been able to agree upon a plan for an international court of justice. The plan was formulated last summer by an advisory committee of jurists sitting at The Hague. Since then it has been submitted to the Council and the Assembly of the League of Nations and has been approved. It will come into operation as soon as the project has been ratified by a majority of the nations belonging to the Leagu

LHC Machine Protection

For nominal beam parameters at 7 TeV/c each of the two LHC proton beams has a stored energy of 362 MJ threatening to damage accelerator equipment in case of uncontrolled beam loss. The energy stored in the magnet system at 7 TeV/c will exceed 10 GJ. In order to avoid damage of accelerator equipment, complex machine protection systems are required. Magnet protection and powering interlock systems must be operational already before commissioning the magnet powering system. Beam operation, throughout the operational cycle from injection to colliding beams, requires fully operational protection systems, including beam interlock systems, beam dumping system, beam instrumentation (mainly beam loss monitors) as well as collimators and beam absorbers. Details of LHC machine protection have been presented on several occasions and the systems involved in protection are well documented [1]. This paper gives an overview of LHC machine protection, discusses the progress with the implementation and presents first results from the commissioning of some systems

A new non-Fermi liquid fixed point

We study a new exchange interaction in which the conduction electrons with pseudo spin $S_c=3/2$ interact with the impurity spin $S_I=1/2$. Due to the overscreening of the impurity spin by higher conduction electron spin, a new non-trivial intermediate coupling strength fixed point is realized. Using the numerical renormalization group (NRG), we show that the low-energy spectra are described by a non-Fermi liquid excitation spectrum. A conformal field theory analysis is compared with NRG results and excellent agreement is obtained. Using the double fusion rule to generate the operator spectrum with the conformal theory, we find that the specific heat coefficient and magnetic susceptibility will diverge as $T^{-2/3}$, that the scaling dimension of an applied magnetic field is $5/6$, and that exchange anisotropy is always relevant. We discuss the possible relevance of our work to two-level system Kondo materials and dilute cerium alloys, and we point out a paradox in understanding the Bethe-Ansatz solutions to the multichannel Kondo model.Comment: Revised. 20 page

Rickettsia parkeri in Amblyomma americanum Ticks, Tennessee and Georgia, USA

To determine the geographic distribution of the newly recognized human pathogen Rickettsia parkeri, we looked for this organism in ticks from Tennessee and Georgia, USA. Using PCR and sequence analysis, we identified R. parkeri in 2 Amblyomma americanum ticks. This rickettsiosis may be underdiagnosed in the eastern United States

Separate Origins of Group I Introns in Two Mitochondrial Genes of the Katablepharid Leucocryptos marina

Mitochondria are descendants of the endosymbiotic α-proteobacterium most likely engulfed by the ancestral eukaryotic cells, and the proto-mitochondrial genome should have been severely streamlined in terms of both genome size and gene repertoire. In addition, mitochondrial (mt) sequence data indicated that frequent intron gain/loss events contributed to shaping the modern mt genome organizations, resulting in the homologous introns being shared between two distantly related mt genomes. Unfortunately, the bulk of mt sequence data currently available are of phylogenetically restricted lineages, i.e., metazoans, fungi, and land plants, and are insufficient to elucidate the entire picture of intron evolution in mt genomes. In this work, we sequenced a 12 kbp-fragment of the mt genome of the katablepharid Leucocryptos marina. Among nine protein-coding genes included in the mt genome fragment, the genes encoding cytochrome b and cytochrome c oxidase subunit I (cob and cox1) were interrupted by group I introns. We further identified that the cob and cox1 introns host open reading frames for homing endonucleases (HEs) belonging to distantly related superfamilies. Phylogenetic analyses recovered an affinity between the HE in the Leucocryptos cob intron and two green algal HEs, and that between the HE in the Leucocryptos cox1 intron and a fungal HE, suggesting that the Leucocryptos cob and cox1 introns possess distinct evolutionary origins. Although the current intron (and intronic HE) data are insufficient to infer how the homologous introns were distributed to distantly related mt genomes, the results presented here successfully expanded the evolutionary dynamism of group I introns in mt genomes

The LHC Injection Tests

A series of LHC injection tests was performed in August and September 2008. The first saw beam injected into sector 23; the second into sectors 78 and 23; the third into sectors 78-67 and sectors 23-34-45. The fourth, into sectors 23-34-45, was performed the evening before the extended injection test on the 10th September which saw both beams brought around the full circumference of the LHC. The tests enabled the testing and debugging of a number of critical control and hardware systems; testing and validation of instrumentation with beam for the first time; deployment, and validation of a number of measurement procedures. Beam based measurements revealed a number of machine configuration issues that were rapidly resolved. The tests were undoubtedly an essential precursor to the successful start of LHC beam commissioning. This paper provides an outline of preparation for the tests, the machine configuration and summarizes the measurements made and individual system performance

Targeting DNA Damage Response and Replication Stress in Pancreatic Cancer

Background and aims: Continuing recalcitrance to therapy cements pancreatic cancer (PC) as the most lethal malignancy, which is set to become the second leading cause of cancer death in our society. The study aim was to investigate the association between DNA damage response (DDR), replication stress and novel therapeutic response in PC to develop a biomarker driven therapeutic strategy targeting DDR and replication stress in PC. Methods: We interrogated the transcriptome, genome, proteome and functional characteristics of 61 novel PC patient-derived cell lines to define novel therapeutic strategies targeting DDR and replication stress. Validation was done in patient derived xenografts and human PC organoids. Results: Patient-derived cell lines faithfully recapitulate the epithelial component of pancreatic tumors including previously described molecular subtypes. Biomarkers of DDR deficiency, including a novel signature of homologous recombination deficiency, co-segregates with response to platinum (P < 0.001) and PARP inhibitor therapy (P < 0.001) in vitro and in vivo. We generated a novel signature of replication stress with which predicts response to ATR (P < 0.018) and WEE1 inhibitor (P < 0.029) treatment in both cell lines and human PC organoids. Replication stress was enriched in the squamous subtype of PC (P < 0.001) but not associated with DDR deficiency. Conclusions: Replication stress and DDR deficiency are independent of each other, creating opportunities for therapy in DDR proficient PC, and post-platinum therapy

The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2,MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. This paper describes the first data release from SDSS-IV, Data Release 13 (DR13), which contains new data, reanalysis of existing data sets and, like all SDSS data releases, is inclusive of previously released data. DR13 makes publicly available 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA,the first data released from this survey. It includes new observations from eBOSS, completing SEQUELS. In addition to targeting galaxies and quasars, SEQUELS also targeted variability-selected objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new reductions ofthe SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification. DR13 releases new reductions of the APOGEE-1data from SDSS-III, with abundances of elements not previously included and improved stellar parameters for dwarf stars and cooler stars. For the SDSS imaging data, DR13 provides new, more robust and precise photometric calibrations. Several value-added catalogs are being released in tandem with DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and an updated red-clump catalog for APOGEE.This paper describes the location and format of the data now publicly available, as well as providing references to the important technical papers that describe the targeting, observing, and data reduction. The SDSS website, http://www.sdss.org, provides links to the data, tutorials and examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ~6-year operations of SDSS-IV.PostprintPeer reviewe