209 research outputs found
Diffusion-weighted MRI reflects proliferative activity in primary CNS lymphoma
Purpose: To investigate if apparent diffusion coefficient (ADC) values within primary central nervous system lymphoma correlate with cellularity and proliferative activity in corresponding histological samples.
Materials and Methods: Echo-planar diffusion-weighted magnetic resonance images obtained from 21 patients with primary central nervous system lymphoma were reviewed retrospectively. Regions of interest were drawn on ADC maps corresponding to the contrast enhancing parts of the tumors. Biopsies from all 21 patients were histologically analyzed. Nuclei count, total nuclei area and average nuclei area were measured. The proliferation index was estimated as Ki-67 positive nuclei divided by total number of nuclei. Correlations of ADC values and histopathologic parameters were determined statistically. Results: Ki-67 staining revealed a statistically significant correlation with ADCmin (r = -0.454, p = 0.038), ADCmean (r = -0.546, p = 0.010) and ADCmax (r = -0.515, p = 0.017). Furthermore, ADCmean correlated in a statistically significant manner with total nucleic area (r = -0.500, p = 0.021). Conclusion: Low ADCmin, ADCmean and ADCmax values reflect a high proliferative activity of primary cental nervous system lymphoma. Low ADCmean values—in concordance with several
previously published studies—indicate an increased cellularity within the tumor
Believable Minecraft Settlements by Means of Decentralised Iterative Planning
Procedural city generation that focuses on believability and adaptability to
random terrain is a difficult challenge in the field of Procedural Content
Generation (PCG). Dozens of researchers compete for a realistic approach in
challenges such as the Generative Settlement Design in Minecraft (GDMC), in
which our method has won the 2022 competition. This was achieved through a
decentralised, iterative planning process that is transferable to similar
generation processes that aims to produce "organic" content procedurally.Comment: 8 pages, 8 figures, to be published in "2023 IEEE Conference on Games
(CoG)
A Convenient Category of Domains
We motivate and define a category of "topological domains",
whose objects are certain topological spaces, generalising
the usual -continuous dcppos of domain theory.
Our category supports all the standard constructions of domain theory,
including the solution of recursive domain equations. It also
supports the construction of free algebras for (in)equational
theories, provides a model of parametric polymorphism,
and can be used as the basis for a theory of computability.
This answers a question of Gordon Plotkin, who asked
whether it was possible to construct a category of domains
combining such properties
Virtual Environments. Seminar - Sommersemester 2003
Dieser Bericht stellt die Ergebnisse des Seminars Virtual
Environments (VE) zusammen. Ein wichtiges Ziel von VE ist die
Immersion, die Einbindung des Benutzers als aktiven Teilnehmer
in eine computergenerierte Welt. Voraussetzung dafür sind
Techniken zur Simulation von Lebendigen virtuellen Welten,
also zur Simulation von 3D-Szenen mit realistischem Verhalten.
Es geht dabei um Kollisionserkennungsalgorithmen, haptisches
Rendering, Navigations- und Interaktionstechniken,
programmierbare Grafik-Hardware, verteilte virtuelle Welten bis
hin zur Modellierung und Simulation von virtuellen Menschen.
Die virtuelle Realität hat sich inzwischen in verschiedenen
Anwendungsbereichen durchgesetzt und wird auch im Rahmen des
SFB 588 Humanoide Roboter - Lernende und kooperierende
multimodale Roboter für die Simulation des humanoiden Roboters
und die Evaluierung der Mensch-Roboter-Schnittstelle eingesetzt
Ultrasound-based "CEUS-Bosniak"classification for cystic renal lesions: an 8-year clinical experience
Purpose Renal cysts comprise benign and malignant entities. Risk assessment profts from CT/MRI imaging using the
Bosniak classifcation. While Bosniak-IIF, -III, and -IV cover complex cyst variants, Bosniak-IIF and -III stand out due to
notorious overestimation. Contrast-enhanced ultrasound (CEUS) is promising to overcome this defcit but warrants standardization. This study addresses the benefts of a combined CEUS and CT/MRI evaluation of renal cysts. The study provides
a realistic account of kidney tumor boards' intricacies in trying to validate renal cysts.
Methods 247 patients were examined over 8 years. CEUS lesions were graded according to CEUS-Bosniak (IIF, III, IV). 55
lesions were resected, CEUS-Bosniak- and CT/MRI-Bosniak-classifcation were correlated with histopathological diagnosis.
Interobserver agreement between the classifcations was evaluated statistically. 105 lesions were followed by ultrasound, and
change in CEUS-Bosniak-types and lesion size were documented.
Results 146 patients (156 lesions) were included. CEUS classifed 67 lesions as CEUS-Bosniak-IIF, 44 as CEUS-BosniakIII, and 45 as CEUS-Bosniak-IV. Histopathology of 55 resected lesions revealed benign cysts in all CEUS-Bosniak-IIF
lesions (2/2), 40% of CEUS-Bosniak-III and 8% of CEUS-Bosniak-IV, whereas malignancy was uncovered in 60% of
CEUS-Bosniak-III and 92% of CEUS-Bosniak-IV. Overall, CEUS-Bosniak-types matched CT/MRI-Bosniak types in 58%
(fair agreement, κ=0.28). CEUS-Bosniak resulted in higher stages than CT/MRI-Bosniak (40%). Ultrasound follow-up of
105 lesions detected no relevant diferences between CEUS-Bosniak-types concerning cysts size. 99% of lesions showed
the same CEUS-Bosniak-type.
Conclusion The CEUS-Bosniak classifcation is an essential tool in clinical practice to diferentiate and monitor renal cystic
lesions and empowers diagnostic work-up and patient care
Characterization of rare germline variants in familial multiple myeloma
Multiple myeloma (MM) is a malignancy of plasma cells, characterized by the presence of monoclonal
immunoglobulin, known as M protein1. MM is preceded by monoclonal gammopathy of undetermined significance (MGUS) which is also a precursor of immunoglobulin light chain (AL) amyloidosis. Previous studies have reported a 2- to 4-fold increased risk of MGUS or MM in first-degree relatives of MM or MGUS patients, suggesting the existence of inherited susceptibility. For many years, high-risk germline predisposing genes have been lacking for MM. However, recent sequencing efforts have proposed a few novel candidates, most notably loss-offunction (LoF) variants in the tumor suppressor gene DIS3 and in the histone demethylase gene KDM1A, and others as recently reviewed in detail in Pertesi et al.
In addition to the suspected rare, high-penetrance variants, genome-wide association studies have identified over 20 common, low-penetrance variants associated with the risk of MM; these were estimated to account for about 15% of the familial MM risk
A Standardized Workflow Based on the STAVIRO Unbaited Underwater Video System for Monitoring Fish and Habitat Essential Biodiversity Variables in Coastal Areas
Essential Biodiversity Variables (EBV) related to benthic habitats and high trophic levels such as fish communities must be measured at fine scale but monitored and assessed at spatial scales that are relevant for policy and management actions. Local scales are important for assessing anthropogenic impacts, and conservation-related and fisheries management actions, while reporting on the conservation status of biodiversity to formulate national and international policies requires much broader scales. Measurements must account for the fact that coastal habitats and fish communities are heterogeneously distributed locally and at larger scales. Assessments based on in situ monitoring generally suffer from poor spatial replication and limited geographical coverage, which is challenging for area-wide assessments. Requirements for appropriate monitoring comprise cost-efficient and standardized observation protocols and data formats, spatially scalable and versatile data workflows, data that comply with the FAIR (Findable, Accessible, Interoperable, and Reusable) principles, while minimizing the environmental impact of measurements. This paper describes a standardized workflow based on remote underwater video that aims to assess fishes (at species and community levels) and habitat-related EBVs in coastal areas. This panoramic unbaited video technique was developed in 2007 to survey both fishes and benthic habitats in a cost-efficient manner, and with minimal effect on biodiversity. It can be deployed in areas where low underwater visibility is not a permanent or major limitation. The technique was consolidated and standardized and has been successfully used in varied settings over the last 12 years. We operationalized the EBV workflow by documenting the field protocol, survey design, image post-processing, EBV production and data curation. Applications of the workflow are illustrated here based on some 4,500 observations (fishes and benthic habitats) in the Pacific, Indian and Atlantic Oceans, and Mediterranean Sea. The STAVIRO’s proven track-record of utility and cost-effectiveness indicates that it should be considered by other researchers for future applications.publishedVersio
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Refining the accuracy of validated target identification through coding variant fine-mapping in type 2 diabetes.
We aggregated coding variant data for 81,412 type 2 diabetes cases and 370,832 controls of diverse ancestry, identifying 40 coding variant association signals (P < 2.2 × 10-7); of these, 16 map outside known risk-associated loci. We make two important observations. First, only five of these signals are driven by low-frequency variants: even for these, effect sizes are modest (odds ratio ≤1.29). Second, when we used large-scale genome-wide association data to fine-map the associated variants in their regional context, accounting for the global enrichment of complex trait associations in coding sequence, compelling evidence for coding variant causality was obtained for only 16 signals. At 13 others, the associated coding variants clearly represent 'false leads' with potential to generate erroneous mechanistic inference. Coding variant associations offer a direct route to biological insight for complex diseases and identification of validated therapeutic targets; however, appropriate mechanistic inference requires careful specification of their causal contribution to disease predisposition
Intravenous Inoculation of a Bat-Associated Rabies Virus Causes Lethal Encephalopathy in Mice through Invasion of the Brain via Neurosecretory Hypothalamic Fibers
The majority of rabies virus (RV) infections are caused by bites or scratches from rabid carnivores or bats. Usually, RV utilizes the retrograde transport within the neuronal network to spread from the infection site to the central nervous system (CNS) where it replicates in neuronal somata and infects other neurons via trans-synaptic spread. We speculate that in addition to the neuronal transport of the virus, hematogenous spread from the site of infection directly to the brain after accidental spill over into the vascular system might represent an alternative way for RV to invade the CNS. So far, it is unknown whether hematogenous spread has any relevance in RV pathogenesis. To determine whether certain RV variants might have the capacity to invade the CNS from the periphery via hematogenous spread, we infected mice either intramuscularly (i.m.) or intravenously (i.v.) with the dog-associated RV DOG4 or the silver-haired bat-associated RV SB. In addition to monitoring the progression of clinical signs of rabies we used immunohistochemistry and quantitative reverse transcription polymerase chain reaction (qRT-PCR) to follow the spread of the virus from the infection site to the brain. In contrast to i.m. infection where both variants caused a lethal encephalopathy, only i.v. infection with SB resulted in the development of a lethal infection. While qRT-PCR did not reveal major differences in virus loads in spinal cord or brain at different times after i.m. or i.v. infection of SB, immunohistochemical analysis showed that only i.v. administered SB directly infected the forebrain. The earliest affected regions were those hypothalamic nuclei, which are connected by neurosecretory fibers to the circumventricular organs neurohypophysis and median eminence. Our data suggest that hematogenous spread of SB can lead to a fatal encephalopathy through direct retrograde invasion of the CNS at the neurovascular interface of the hypothalamus-hypophysis system. This alternative mode of virus spread has implications for the post exposure prophylaxis of rabies, particularly with silver-haired bat-associated RV
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