Multiple meningiomas: clinical, radiological, surgical, and pathological findings with outcome in four cats

The present report describes the clinical signs, magnetic resonance imaging (MRI) findings, surgical procedure, pathological findings and follow-up in four cats with multiple meningiomas; three castrated male and one spayed female domestic shorthair indoor cats, ranging in age from 11 to 14 years. In three of four cats, clinical signs at presentation were suggestive of a focal lesion. Three cats had two meningiomas and one had four meningiomas. Most of the tumours were supratentorial, one arose from the tentorium and one was infratentorial. The duration of presenting signs before surgery ranged from 10 days to 11 months. Postoperative MRI revealed complete gross tumour removal in three cases. In one cat with two cranial fossa meningiomas, subtotal excision with a small basal remnant (2 x 2 mm) of the ventral part of one meningioma lying on the floor of the skull, was observed. Based on histopathological architecture, six tumours revealed features of a transitional subtype meningioma, and four of a meningotheliomatous meningioma. In each cat, the multiple meningiomas were all assigned to the same histopathological group. The preoperative presenting signs had resolved by the follow-up examinations 4 weeks after surgery in two cats. Long-term follow-up evaluation revealed that surgically-induced or exacerbated neurological deficits in two cats had completely or almost completely resolved within 8 weeks of surgery. All patients are still alive 12 to 21 months after surgery and no clinical signs of recurrence could be detected at that time.

Cerebral correlates of muscle tone fluctuations in restless legs syndrome: A pilot study with combined functional magnetic resonance imaging and anterior tibial muscle electromyography

BACKGROUND: The pathology of restless legs syndrome (RLS) is still not understood. To investigate the pathomechanism of the disorder further we recorded a surface electromyogram (EMG) of the anterior tibial muscle during functional magnetic resonance imaging (fMRI) in patients with idiopathic RLS. METHODS: Seven subjects with moderate to severe RLS were investigated in the present pilot study. Patients were lying supine in the scanner for over 50min and were instructed not to move voluntarily. Sensory leg discomfort (SLD) was evaluated on a 10-point Likert scale. For brain image analysis, an algorithm for the calculation of tonic EMG values was developed. RESULTS: We found a negative correlation of tonic EMG and SLD (p <0.01). This finding provides evidence for the clinical experience that RLS-related subjective leg discomfort increases during muscle relaxation at rest. In the fMRI analysis, the tonic EMG was associated with activation in motor and somatosensory pathways and also in some regions that are not primarily related to motor or somatosensory functions. CONCLUSIONS: By using a newly developed algorithm for the investigation of muscle tone-related changes in cerebral activity, we identified structures that are potentially involved in RLS pathology. Our method, with some modification, may also be suitable for the investigation of phasic muscle activity that occurs during periodic leg movements.

Hardware accelerated ray cast of volume data and volume gradient for an optimized splines-based multi-resolution 2D-3D registration

This paper describes a method for DRR generation as well as for volume gradients projection using hardware accelerated 2D texture mapping and accumulation buffering and demonstrates its application in 2D-3D registration of X-ray fluoroscopy to CT images. The robustness of the present registration scheme are guaranteed by taking advantage of a coarse-to-fine processing of the volume/image pyramids based on cubic B-splines. A human cadaveric spine specimen together with its ground truth was used to compare the present scheme with a purely software-based scheme in three aspects: accuracy, speed, and capture ranges. Our experiments revealed an equivalent accuracy and capture ranges but with much shorter registration time with the present scheme. More specifically, the results showed 0.8 mm average target registration error, 55 second average execution time per registration, and 10 mm and 10° capture ranges for the present scheme when tested on a 3.0 GHz Pentium 4 computer.

Spatial Assessment of Erosion and its Impact on Soil Fertility in the Tajik Foothills

Efficient planning of soil conservation measures requires, first, to understand the impact of soil erosion on soil fertility with regard to local land cover classes; and second, to identify hot spots of soil erosion and bright spots of soil conservation in a spatially explicit manner. Soil organic carbon (SOC) is an important indicator of soil fertility. The aim of this study was to conduct a spatial assessment of erosion and its impact on SOC for specific land cover classes. Input data consisted of extensive ground truth, a digital elevation model and Landsat 7 imagery from two different seasons. Soil spectral reflectance readings were taken from soil samples in the laboratory and calibrated with results of SOC chemical analysis using regression tree modelling. The resulting model statistics for soil degradation assessments are promising (R2=0.71, RMSEV=0.32). Since the area includes rugged terrain and small agricultural plots, the decision tree models allowed mapping of land cover classes, soil erosion incidence and SOC content classes at an acceptable level of accuracy for preliminary studies. The various datasets were linked in the hot-bright spot matrix, which was developed to combine soil erosion incidence information and SOC content levels (for uniform land cover classes) in a scatter plot. The quarters of the plot show different stages of degradation, from well conserved land to hot spots of soil degradation. The approach helps to gain a better understanding of the impact of soil erosion on soil fertility and to identify hot and bright spots in a spatially explicit manner. The results show distinctly lower SOC content levels on large parts of the test areas, where annual crop cultivation was dominant in the 1990s and where cultivation has now been abandoned. On the other hand, there are strong indications that afforestations and fruit orchards established in the 1980s have been successful in conserving soil resources.

Ultrasound-guided paravertebral puncture and placement of catheters in human cadavers: an imaging study

BACKGROUND: During paravertebral block, the anterolateral limit of the paravertebral space, which consists of the pleura, should preferably not be perforated. Also it is possible that, during the block, the constant superior costotransverse ligament can be missed in the loss-of-resistance technique. We therefore aimed to develop a new technique for an ultrasound-guided puncture of the paravertebral space. METHODS: We performed 20 punctures and catheter placements in 10 human cadavers. A sonographic view showing the pleura and the superior costotransverse ligament was obtained with a slightly oblique scan using a curved array transducer. After inline approach, injection of 10 ml normal saline confirmed the correct position of the needle tip, distended the space, and enabled catheter insertion. The spread of contrast dye injected through the catheters was assessed by CT scans. RESULTS: The superior costotransverse ligament and the paravertebral space were easy to identify. The needle tip reached the paravertebral space without problems under visualization. In contrast, the introduction of the catheter was difficult. The CT scan revealed a correct paravertebral spread of contrast in 11 cases. Out of the remaining, one catheter was found in the pleural space, in six cases there was an epidural, and in two cases there was a prevertebral spread of contrast dye. CONCLUSIONS: We successfully developed a technique for an accurate ultrasound-guided puncture of the paravertebral space. We also showed that when a catheter is introduced through the needle with the tip lying in the paravertebral space, there is a high probability of catheter misplacement into the epidural, mediastinal, or pleural spaces.

Illusions of fusions: assessing cervical vertebral fusion on lateral cephalograms, multidetector computed tomographs, and cone-beam computed tomographs

INTRODUCTION The aims of this study were to compare lateral cephalograms with other radiologic methods for diagnosing suspected fusions of the cervical spine and to validate the assessment of congenital fusions and osteoarthritic changes against the anatomic truth. METHODS Four cadaver heads were selected with fusion of vertebrae C2 and C3 seen on a lateral cephalogram. Multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) were performed and assessed by 5 general radiologists and 5 oral radiologists, respectively. Vertebrae C2 and C3 were examined for osseous fusions, and the left and right facet joints were diagnosed for osteoarthritis. Subsequently, the C2 and C3 were macerated and appraised by a pathologist. Descriptive analysis was performed, and interrater agreements between and within the groups were computed. RESULTS All macerated specimens showed osteoarthritic findings of varying degrees, but no congenital bony fusion. All observers agreed that no fusion was found on MDCT or CBCT. They disagreed on the prevalence of osteoarthritic deformities (general radiologists/MDCT, 100%; oral radiologists/CBCT, 93.3%) and joint space assessment in the facet joints (kappa = 0.452). The agreement within the rater groups differed considerably (general radiologists/MDCT, kappa = 0.612; oral radiologists/CBCT, kappa = 0.240). CONCLUSIONS Lateral cephalograms do not provide dependable data to assess the cervical spine for fusions and cause false-positive detections. Both MDCT interpreted by general radiologists and CBCT interpreted by oral radiologists are reliable methods to exclude potential fusions. Degenerative osteoarthritic changes are diagnosed more accurately and consistently by general radiologists evaluating MDCT.

High altitude journeys and flights are associated with an increased risk of flares in inflammatory bowel disease patients

BACKGROUND AND AIMS Hypoxia can induce inflammation in the gastrointestinal tract. However, the impact of hypoxia on the course of inflammatory bowel disease (IBD) is poorly understood. We aimed to evaluate whether flights and/or journeys to regions lying at an altitude of >2000m above the sea level are associated with flare-ups within 4weeks of the trip. METHODS IBD patients with at least one flare-up during a 12-month observation period were compared to a group of patients in remission. Both groups completed a questionnaire. RESULTS A total of 103 IBD patients were included (43 with Crohn's disease (CD): mean age 39.3±14.6years; 60 with ulcerative colitis (UC): mean age 40.4±15.1years). Fifty-two patients with flare-ups were matched to 51 patients in remission. IBD patients experiencing flare-ups had more frequently undertaken flights and/or journeys to regions >2000m above sea level within four weeks of the flare-up when compared to patients in remission (21/52 [40.4%] vs. 8/51 [15.7%], p=0.005). CONCLUSIONS Journeys to high altitude regions and/or flights are a risk factor for IBD flare-ups occurring within 4weeks of travel.

Lipid biomarkers in Holocene and glacial sediments from ancient Lake Ohrid (Macedonia, Albania)

Abstract. Organic matter preserved in Lake Ohrid sediments originates from aquatic and terrestrial sources. Its variable composition reflects climate-controlled changes in the lake basin’s hydrology and related organic matter export, i.e. changes in primary productivity, terrestrial plant matter input and soil erosion. Here, we present first results from lipid biomarker investigations of Lake Ohrid sediments from two near-shore settings: site Lz1120 near the southern shore, with low-lying lands nearby and probably influenced by river discharge, and site Co1202 which is close to the steep eastern slopes. Variable proportions of terrestrial n-alkanoic acids and n-alkanols as well as compositional changes of !- hydroxy acids document differences in soil organic matter supply between the sites and during different climate stages (glacial, Holocene, 8.2 ka cooling event). Changes in the vegetation cover are suggested by changes in the dominant chain length of terrestrial n-alkanols. Effective microbial degradation of labile organic matter and in situ contribution of organic matter derived from the microbes themselves are both evident in the sediments. We found evidence for anoxic conditions within the photic zone by detecting epicholestanol and tetrahymanol from sulphur-oxidising phototrophic bacteria and bacterivorous ciliates and for the influence of a settled human community from the occurrence of coprostanol, a biomarker for human and animal faeces (pigs, sheep, goats), in an early Holocene sample. This study illustrates the potential of lipid biomarkers for future environmental reconstructions using one of Europe’s oldest continental climate archives, Lake Ohrid.

Statistical Methods and the Meaning of Probabilities. A Philosopher Looks at Statistics

The talk starts out with a short introduction to the philosophy of probability. I highlight the need to interpret probabilities in the sciences and motivate objectivist accounts of probabilities. Very roughly, according to such accounts, ascriptions of probabilities have truth-conditions that are independent of personal interests and needs. But objectivist accounts are pointless if they do not provide an objectivist epistemology, i.e., if they do not determine well-defined methods to support or falsify claims about probabilities. In the rest of the talk I examine recent philosophical proposals for an objectivist methodology. Most of them take up ideas well-known from statistics. I nevertheless find some proposals incompatible with objectivist aspirations.

Vulnerability to Heatwaves, Floods and Mass Movements in Mountainous Terrain: Test Cases in South Tyrol

South Tyrol is a region that has been often affected by various mountain hazards such as floods, flash floods, debris flows, rock falls, and snow avalanches. Furthermore, areas located in lower altitudes are often influenced by high temperatures and heat waves. Climate change is expected to influence the frequency, magnitude, and spatial extent of these natural phenomena. For this reason, local authorities and other stakeholders are in need of tools that can enable them to reduce the risk posed by these processes. In the present study, a variety of methods are applied at local level in different places in South Tyrol that aim at: (1) the assessment of future losses caused by the occurrence of debris flows by using a vulnerability curve, (2) the assessment of social vulnerability based on the risk awareness of the exposed people to floods, and (3) the assessment of spatial exposure and social vulnerability of the exposed population to heat waves. The results show that, in South Tyrol, the risk to a number of hazards can be reduced by: (1) improving documentation for past events in order to improve existing vulnerability curves and the assessment of future losses, (2) raising citizens' awareness and responsibility to improve coping capacity to floods, and (3) extending heat wave early warning systems to more low-lying areas of South Tyrol.

The Nature of Scientific Proof in the Age of Simulations. Is numerical mimicry a third way of establishing truth?

Is numerical mimicry a third way of establishing truth? Kevin Heng received his M.S. and Ph.D. in astrophysics from the Joint Institute for Laboratory Astrophysics (JILA) and the University of Colorado at Boulder. He joined the Institute for Advanced Study in Princeton from 2007 to 2010, first as a Member and later as the Frank & Peggy Taplin Member. From 2010 to 2012 he was a Zwicky Prize Fellow at ETH Z¨urich (the Swiss Federal Institute of Technology). In 2013, he joined the Center for Space and Habitability (CSH) at the University of Bern, Switzerland, as a tenure-track assistant professor, where he leads the Exoplanets and Exoclimes Group. He has worked on, and maintains, a broad range of interests in astrophysics: shocks, extrasolar asteroid belts, planet formation, fluid dynamics, brown dwarfs and exoplanets. He coordinates the Exoclimes Simulation Platform (ESP), an open-source set of theoretical tools designed for studying the basic physics and chemistry of exoplanetary atmospheres and climates (www.exoclime.org). He is involved in the CHEOPS (Characterizing Exoplanet Satellite) space telescope, a mission approved by the European Space Agency (ESA) and led by Switzerland. He spends a fair amount of time humbly learning the lessons gleaned from studying the Earth and Solar System planets, as related to him by atmospheric, climate and planetary scientists. He received a Sigma Xi Grant-in-Aid of Research in 2006

A feasible theory of truth over combinatory algebra

We define an applicative theory of truth TPT which proves totality exactly for the polynomial time computable functions. TPT has natural and simple axioms since nearly all its truth axioms are standard for truth theories over an applicative framework. The only exception is the axiom dealing with the word predicate. The truth predicate can only reflect elementhood in the words for terms that have smaller length than a given word. This makes it possible to achieve the very low proof-theoretic strength. Truth induction can be allowed without any constraints. For these reasons the system TPT has the high expressive power one expects from truth theories. It allows embeddings of feasible systems of explicit mathematics and bounded arithmetic. The proof that the theory TPT is feasible is not easy. It is not possible to apply a standard realisation approach. For this reason we develop a new realisation approach whose realisation functions work on directed acyclic graphs. In this way, we can express and manipulate realisation information more efficiently.

Talking About Climate Change: The Ecological Crisis and Narrative Form

This article examines the issue of climate change in the context of ecocriticism. It analyzes some of the narrative forms employed in the mediation of climate change science, focusing on those used by mediators who are not themselves scientists in the transmission of scientific information to a nonspecialist readership or audience. It reviews four relevant works that combine the communication of scientific theories and facts with pedagogical and motivational impulses. These include David Guggenheimer’s documentary film An Inconvenient Truth, Fred Pearce’s book The Last Generation: How Nature Will Take Her Revenge for Climate Change and the climate change manuals The Live Earth Global Warming Survival Handbook and How to Save the Climate.