Mechanical concept of the neurosurgical robot ‘Minerva'

We describe a robot capable of performing all procedures necessary to carry out a complete stereotactic neurosurgical operation under the control and supervision of a surgeon. The operation consists of the introduction of a small probe with diameter 2-3 mm through a hole without trepanation. The robot has been built and is now being tested and evaluated. The accompanying control software as well as various medical probes are either in development or partially tested. The installation will be able to carry out a complete intervention under the surveillance of a computed tomography scanner. In this article we emphasize the design choices required to eliminate gearing backlash in a crucial degree of freedo

Random-walk approach to mapping nodal regions of N-body wave functions: Ground-state Hartree-Fock wave functions for Li-C

Despite the widespread acceptance of the relevance of the nodes of one‐body electronic wave functions (atomic or molecular orbitals) in determining chemical properties, relatively little is known about the corresponding nodes of many‐body wave functions. As an alternative to mapping the nodal surfaces present in the ground states of many‐electron systems, we have focused instead on the structural domains implied by these surfaces. In the spirit of Monte Carlo techniques, the nodal hypervolumes of a series of atomic N‐body Hartree–Fock level electronic wave functions have been mapped using a random‐walk simulation in 3N dimensional configuration space. The basic structural elements of the domain of atomic or molecular wave functions are identified as nodal regions (continuous volumes of the same sign) and permutational cells (identical building blocks). Our algorithm determines both the relationships among nodal regions or cells (topology) as well as the geometric properties within each structural domain. Our results indicate that ground‐state Hartree–Fock wave functions generally consist of four equivalent nodal regions (two positive and two negative), each constructed from one or more permutational cells. We have developed an operational method to distinguish otherwise identical permutational cells. The limitations and most probable sources of error associated with this numerical method are discussed as are directions for future research

Root herbivore performance suppressed when feeding on a jasmonate-induced pasture grass

1. Plants defend themselves from insect herbivore attack using a range of physical and chemical defences which are in many cases regulated by phytohormones such as jasmonates. While much more is known about how jasmonates regulate defence against above‐ground herbivores (e.g. herbivores of leaves), there is increasing interest in how they influence below‐ground defences. 2. For the Poaceae, most below‐ground studies focus on highly domesticated cereals. Here it is demonstrated how exogenous application of methyl jasmonate (MeJA) to the leaf blades of a non‐domesticated pasture grass (Microlaena stipoides) caused a more than two‐fold decrease in relative growth rate (RGR) of a root‐feeding chafer (Dermolepida albohirtum). MeJA treatment did not affect root consumption rates, but substantially reduced the efficiency of conversion of ingested food to body mass. 3. Non‐targeted metabolomics identified significant changes in the metabolome of MeJA‐induced plants, with three compounds (a galactolipid, a trihydroxy fatty acid and a lysophospholipid) found to be correlated with herbivore RGR, although their roles in herbivore defence remain uncertain. 4. This study suggests that an important Australian pasture grass can become better defended against root herbivores via enhanced jasmonate activity

Intragenic alternative splicing coordination is essential for Caenorhabditis elegans slo-1 gene function

Alternative splicing is critical for diversifying eukaryotic proteomes, but the rules governing and coordinating splicing events among multiple alternate splice sites within individual genes are not well understood. We developed a quantitative PCR-based strategy to quantify the expression of the 12 transcripts encoded by the Caenorhabditis elegans slo-1 gene, containing three alternate splice sites. Using conditional probability-based models, we show that splicing events are coordinated across these sites. Further, we identify a point mutation in an intron adjacent to one alternate splice site that disrupts alternative splicing at all three sites. This mutation leads to aberrant synaptic transmission at the neuromuscular junction. In a genomic survey, we found that a UAAAUC element disrupted by this mutation is enriched in introns flanking alternate exons in genes with multiple alternate splice sites. These results establish that proper coordination of intragenic alternative splicing is essential for normal physiology of slo-1 in vivo and identify putative specialized cis-regulatory elements that regulate the coordination of intragenic alternative splicing

The effect of communication between the right and left liver on the outcome of surgical drainage for jaundice due to malignant obstruction at the hilus of the liver

Debate continues regarding the optimal management of irresectable malignant proximal biliary obstruction. Controversy exists concerning the ability of unilateral drainage to provide adequate biliary decompression with tumors that have occluded the communication between the right and left hepatic ductal systems. Between October 1986 and October 1989, 18 patients with malignant proximal biliary obstruction were treated by an intrahepatic biliary enteric bypass. Patients were divided into two groups based on the presence or absence of a communication between the right and left biliary systems. In Group I (n = 9), there was free communication; and in Group II (n = 9) there was no communication. There were two perioperative deaths (11%) one due to persistent cholangitis and the other to myocardial insufficiency both with one death in each group. The median survival (excluding perioperative deaths) was 5.6 months. Comparison of pre- and postoperative serum levels of bilirubin and alkaline phosphatase showed a significant decrease in each group, but no difference between the groups in the size of the reduction. Sixteen patients survived at least three months and the palliation was judged as excellent in eight, fair in five, and unchanged in three. These results demonstrate the effectiveness of biliary enteric bypass regardless of communication between the left and right biliary ductal systems.H. U. Baer, M. Rhyner, S. C. Stain, P. W. Glauser, A. R. Dennison, G. J. Maddern, and L. H. Blumgar

Continuum and line modeling of disks around young stars II. Line diagnostics for GASPS from the DENT grid

Aims. We want to understand the chemistry and physics of disks on the basis of a large unbiased and statistically relevant grid of disk models. One of the main goals is to explore the diagnostic power of various gas emission lines and line ratios for deriving main disk parameters such as the gas mass. Methods. We explore the results of the DENT grid (Disk Evolution with Neat Theory) that consists of 300 000 disk models with 11 free parameters. Through a statistical analysis, we search for correlations and trends in an effort to find tools for disk diagnostic. Results. All calculated quantities like species masses, temperatures, continuum and line fluxes differ by several orders of magnitude across the entire parameter space. The broad distribution of these quantities as a function of input parameters shows the limitation of using a prototype T Tauri or Herbig Ae/Be disk model. The statistical analysis of the DENT grid shows that CO gas is rarely the dominant carbon reservoir in disks. Models with large inner radii (10 times the dust condensation radius) and/or shallow surface density gradients lack massive gas phase water reservoirs. Also, 60% of the disks have gas temperatures averaged over the oxygen mass in the range between 15 and 70 K; the average gas temperatures for CO and O differ by less than a factor two. Studying the observational diagnostics, the [CII] 158 \mum fine structure line flux is very sensitive to the stellar UV flux and presence of a UV excess and it traces the outer disk radius (Rout). In the submm, the CO low J rotational lines also trace Rout. Low [OI] 63/145 line ratios (< a few) can be explained with cool atomic O gas in the uppermost surface layers leading to self-absorption in the 63 \mum line; this occurs mostly for massive non-flaring, settled disk models without UV excess. ... abbreviatedComment: 15 pages, 25 figures, accepted for publication in A&

Treatment of infantile spasms: emerging insights from clinical and basic science perspectives.

Infantile spasms is an epileptic encephalopathy of early infancy with specific clinical and electroencephalographic (EEG) features, limited treatment options, and a poor prognosis. Efforts to develop improved treatment options have been hindered by the lack of experimental models in which to test prospective therapies. The neuropeptide adrenocorticotropic hormone (ACTH) is effective in many cases of infantile spasms, although its mechanism(s) of action is unknown. This review describes the emerging candidate mechanisms that can underlie the therapeutic effects of ACTH in infantile spasms. These mechanisms can ultimately help to improve understanding and treatment of the disease. An overview of current treatments of infantile spasms, novel conceptual and experimental approaches to infantile spasms treatment, and a perspective on remaining clinical challenges and current research questions are presented here. This summary derives from a meeting of specialists in infantile spasms clinical care and research held in New York City on June 14, 2010

International Veterinary Epilepsy Task Force consensus proposal: Medical treatment of canine epilepsy in Europe

In Europe, the number of antiepileptic drugs (AEDs) licensed for dogs has grown considerably over the last years. Nevertheless, the same questions remain, which include, 1) when to start treatment, 2) which drug is best used initially, 3) which adjunctive AED can be advised if treatment with the initial drug is unsatisfactory, and 4) when treatment changes should be considered. In this consensus proposal, an overview is given on the aim of AED treatment, when to start long-term treatment in canine epilepsy and which veterinary AEDs are currently in use for dogs. The consensus proposal for drug treatment protocols, 1) is based on current published evidence-based literature, 2) considers the current legal framework of the cascade regulation for the prescription of veterinary drugs in Europe, and 3) reflects the authors’ experience. With this paper it is aimed to provide a consensus for the management of canine idiopathic epilepsy. Furthermore, for the management of structural epilepsy AEDs are inevitable in addition to treating the underlying cause, if possible

The Taurus Spitzer Survey: New Candidate Taurus Members Selected Using Sensitive Mid-Infrared Photometry

We report on the properties of pre-main-sequence objects in the Taurus molecular clouds as observed in 7 mid- and far-infrared bands with the Spitzer Space Telescope. There are 215 previously-identified members of the Taurus star-forming region in our ~44 square degree map; these members exhibit a range of Spitzer colors that we take to define young stars still surrounded by circumstellar dust (noting that ~20% of the bonafide Taurus members exhibit no detectable dust excesses). We looked for new objects in the survey field with similar Spitzer properties, aided by extensive optical, X-ray, and ultraviolet imaging, and found 148 candidate new members of Taurus. We have obtained follow-up spectroscopy for about half the candidate sample, thus far confirming 34 new members, 3 probable new members, and 10 possible new members, an increase of 15-20% in Taurus members. Of the objects for which we have spectroscopy, 7 are now confirmed extragalactic objects, and one is a background Be star. The remaining 93 candidate objects await additional analysis and/or data to be confirmed or rejected as Taurus members. Most of the new members are Class II M stars and are located along the same cloud filaments as the previously-identified Taurus members. Among non-members with Spitzer colors similar to young, dusty stars are evolved Be stars, planetary nebulae, carbon stars, galaxies, and AGN.Comment: Accepted to ApJS. Two large online-only figures available with the preprint here: http://web.ipac.caltech.edu/staff/rebull/research.htm