julilili42/papers huggingface dataset:
Two threatened coexisting indigenous conifer species in the dry Afromontane forests of Ethiopia are associated with distinct arbuscular mycorrhizal fungal communities
2006-10-01

The molecular diversity of arbuscular mycorrhizal (AM) fungi colonizing roots of Podocarpus falcatus (Thunb.) R.Br. (Podocarpaceae) in the dry Afromontane forests of Ethiopia was investigated. The nuclear gene coding for small subunit ribosomal RNA (nucSSU rDNA) was amplified from colonized roots of P. falcatus, cloned, and sequenced using AM fungal specific primers. Phylogenetic analyses revealed that the glomeromycetous sequences from mycorrhizae of P. falcatus belong to the Glomeraceae, Diversisporaceae, and Archaeosporaceae. Overall, 16 Glomus , three Diversispora , and one Archaeospora sequence types were identified. These sequence types were distinct and only distantly related to sequences from the available defined species. The composition of the AM fungal communities differed significantly between the two study sites. Comparison of the AM fungal community composition of P. falcatus with that of previously investigated Juniperus procera Hochst. ex Endl. (Cupressaceae), the only coexisting indigenous conifer tree species in the dry Afromontane forest ecosystem, yields that the two tree species are colonized by distinct AM fungal communities. This suggests that fungal communities are host plant specific in the natural stand conditions. Therefore, in the conservation of these endangered species and restoration of the degraded ecosystem, the use of appropriate mycorrhizal fungi should be taken into account in future projects.
Lesion of the pedunculopontine nucleus reverses hyperactivity of the subthalamic nucleus and substantia nigra pars reticulata in a 6‐hydroxydopamine rat model
2006-10-01

Abstract The pedunculopontine nucleus (PPN) and the subthalamic nucleus (STN) are reciprocally connected by excitatory projections. In the 6‐hydroxydopamine (6‐OHDA) rat model the PPN was found to be hyperactive. Similarly, the STN and the substantia nigra pars reticulata (SNr) showed increased activity in Parkinson's disease (PD) animal models. A lesion of the STN was shown to restore increased activity levels in the SNr of 6‐OHDA‐treated rats. As the STN and the PPN were reciprocally connected by excitatory projections and both structures were shown to be hyperactive in PD animal models, the present study was performed in order to investigate the changes in neuronal activity of the STN and SNr under urethane anesthesia after unilateral ibotenic acid lesioning of the PPN in animals with previous unilateral 6‐OHDA lesions of the substantia nigra pars compacta (SNc). The firing rate of STN neurons significantly increased from 10.3 ± 0.6 spikes/s (mean ± SEM) to 17.8 ± 1.8 spikes/s after SNc lesion and returned to normal levels of 10.8 ± 0.7 spikes/s after additional lesion of the PPN. Similarly, the firing rate of SNr neurons significantly increased from 19.0 ± 1.1 to 25.9 ± 1.4 spikes/s after SNc lesion, the hyperactivity being reversed after additional PPN lesion to 16.8 ± 1.2 spikes/s. The reversal of STN and SNr hyperactivity of 6‐OHDA‐treated rats by additional PPN lesion suggests an important modulatory influence of the PPN on STN activity. Moreover, these findings could indicate a new therapeutic strategy in PD by interventional modulation of the PPN.
A Combined Monte-Carlo Localization and Tracking Algorithm for RoboCup
2006-10-01

Self-localization is a major research task in mobile robotics for several years. Efficient self-localization methods have been developed, among which probabilistic Monte-Carlo localization (MCL) is one of the most popular. It enables robots to localize themselves in real-time and to recover from localization errors. However, even those versions of MCL using an adaptive number of samples need at least a minimum in the order of 100 samples to compute an acceptable position estimation. This paper presents a novel approach to MCL based on images from an omnidirectional camera system. The approach uses an adaptive number of samples that drops down to a single sample if the pose estimation is sufficiently accurate. We show that the method enters this efficient tracking mode after a few cycles and remains there using only a single sample for more than 90% of the cycles. Nevertheless, it is still able to cope with the kidnapped robot problem
A new case of Carney triad: gastrointestinal stromal tumours and leiomyoma of the oesophagus do not show activating mutations of KIT and platelet-derived growth factor receptor α
2006-10-01

The Carney triad is a rare syndrome of unknown aetiology, with synchronous or metachronous appearance of rare neoplasms: gastrointestinal stromal tumours (GISTs), pulmonary chondromas and extra-adrenal paragangliomas. In most cases, the Carney triad is incomplete. The combination encountered typically, GISTs and pulmonary chondromas, was also seen in our patient, a 22-year-old woman. She was diagnosed with the triad after Billroth II gastrectomy for histologically proved gastric GISTs. The diagnosis of pulmonary chondromas was confirmed by transthoracic, computed tomography-guided needle biopsy. An oesophageal leiomyoma was resected 2 years after the initial diagnosis, on suspicion of paraganglioma. The clinical course of the patient has been uneventful since. The last follow-up was carried out 6 years after the initial diagnosis. On histological examination, the cells of gastric GIST were partly positive for CD34, whereas CD117 was expressed in all areas in variable intensity and S-100 protein was negative. The oesophageal tumour was classified as leiomyoma due to strong immunopositivity for smooth muscle actin and desmin, being negative for CD34 and CD117. Two different gastric GIST lesions as well as the oesophageal leiomyoma and normal tissue were analysed for activating mutations in common hot spots of KIT (exon 9 and 11) and platelet-derived growth factor receptor α (exon 18), but in all probes wild-type sequences were found. These results are in accordance with the first published analyses of GIST lesions from Carney patients.
Enhanced visual realism by incorporating camera image effects
2006-10-01

In video see-through augmented reality (AR), virtual objects are overlaid over digital video images. One particular problem of this image mixing process is that the visual appearance of the computer graphics differs strongly from the real background image. The reason for this is that typical AR systems use fast but simple real-time rendering techniques for displaying virtual objects. In this paper, methods for reducing the impact of three effects which make virtual and real objects easily distinguishable are presented. The first effect is camera image noise, which is contained in the data delivered by the image sensor used for capturing the real scene. The second effect considered is edge aliasing, which makes distinguishing virtual objects from real objects simple. Finally, we consider motion blur, which is caused by the temporal integration of color intensities in the image sensor during fast movements of the camera or observed objects. In this paper, we present a system for generating a realistic simulation of image noise based on a new camera calibration step. Additionally, a rendering algorithm is introduced, which performs a smooth blending between the camera image and virtual objects at their boundary in order to reduce aliasing. Lastly, a rendering method is presented, which produces motion blur according to the current camera movement. The implementation of the new rendering techniques utilizes the programmability of modern graphics processing units (GPUs) and delivers real-time frame rates.
Natural Disasters in the Chronographia of John Malalas: Reflections on their Function—An Initial Sketch
2006-10-01

Christian chronicles have been regarded for a long time as an inferior sub-genre of historiography. One of the intentions of this article is to contribute towards a revision of this assessment—it does so through analysing the way natural disasters have been handled in the Chronographia of the Byzantine chronicler John Malalas. In accordance with the norms specific to the genre of Christian chronicles, Malalas too writes within a mould of salvation history, and interprets events as a manifestation of the workings of divine will. Especially during the reign of the emperor Justinian (527–65) the author observes the occurrence of several natural disasters, yet adheres to the view that these were not to be regarded as signs of an approaching end of the world. Instead, it would seem, that he wished to characterise the age of Justinian as an age of fear. As God spread fear through natural disasters so as to induce people to lead a life pleasing to God, the emperor too, at another level, disseminated fear in order to live up to his role as God's representative. Malalas interpreted contemporary events in terms of a retributive theology rooted in the Old Testament and for whose currency evidence could be found at different places during the sixth century.
Post-Genome Research on the Biosynthesis of Ergot Alkaloids
2006-10-01

Genome sequencing provides new opportunities and challenges for identifying genes for the biosynthesis of secondary metabolites. A putative biosynthetic gene cluster of fumigaclavine C, an ergot alkaloid of the clavine type, was identified in the genome sequence of ASPERGILLUS FUMIGATUS by a bioinformatic approach. This cluster spans 22 kb of genomic DNA and comprises at least 11 open reading frames (ORFs). Seven of them are orthologous to genes from the biosynthetic gene cluster of ergot alkaloids in CLAVICEPS PURPUREA. Experimental evidence of the identified cluster was provided by heterologous expression and biochemical characterization of two ORFs, FgaPT1 and FgaPT2, in the cluster of A. FUMIGATUS, which show remarkable similarities to dimethylallyltryptophan synthase from C. PURPUREA and function as prenyltransferases. FgaPT2 converts L-tryptophan to dimethylallyltryptophan and thereby catalyzes the first step of ergot alkaloid biosynthesis, whilst FgaPT1 catalyzes the last step of the fumigaclavine C biosynthesis, i. e., the prenylation of fumigaclavine A at C-2 position of the indole nucleus. In addition to information obtained from the gene cluster of ergot alkaloids from C. PURPUREA, the identification of the biosynthetic gene cluster of fumigaclavine C in A. FUMIGATUS opens an alternative way to study the biosynthesis of ergot alkaloids in fungi.
IN VITRO ACTIVITY OF ARTEMISONE COMPARED WITH ARTESUNATE AGAINST PLASMODIUM FALCIPARUM
2006-10-01

Artemisinins show the potential for neurotoxicity in preclinical studies. Artemisone is a leading candidate of second-generation semi-synthetic artemisinin derivatives for antimalarial therapy devoid of neurotoxicity. Artemisone showed 3–5-fold higher in vitro activity (50% effective concentration (EC 50 ) = 0.14 nmol/L, EC 90 = 2.55 nmol/L) than artesunate against fresh Plasmodium falciparum isolates from Gabon and a high-activity correlation indicates a shared drug target.
Induction of Autoimmunity by Expansion of Autoreactive CD4+CD62Llow Cells In Vivo
2006-10-01

Abstract The prerequisites of peripheral activation of self-specific CD4+ T cells that determine the development of autoimmunity are incompletely understood. SJL mice immunized with myelin proteolipid protein (PLP) 139–151 developed experimental autoimmune encephalomyelitis (EAE) when pertussis toxin (PT) was injected at the time of immunization but not when injected 6 days later, indicating that PT-induced alterations of the peripheral immune response lead to the development of autoimmunity. Further analysis using IAs/PLP139–151 tetramers revealed that PT did not change effector T cell activation or regulatory T cell numbers but enhanced IFN-γ production by self-specific CD4+ T cells. In addition, PT promoted the generation of CD4+CD62Llow effector T cells in vivo. Upon adoptive transfer, these cells were more potent than CD4+CD62Lhigh cells in inducing autoimmunity in recipient mice. The generation of this population was paralleled by higher expression of the costimulatory molecules CD80, CD86, and B7-DC, but not B7-RP, PD-1, and B7-H1 on CD11c+CD4+ dendritic cells whereas CD11c+CD8α+ dendritic cells were not altered. Collectively, these data demonstrate the induction of autoimmunity by specific in vivo expansion of CD4+CD62Llow cells and indicate that CD4+CD62Llow effector T cells and CD11c+CD4+ dendritic cells may be attractive targets for immune interventions to treat autoimmune diseases.
Myofiber Degeneration in Autosomal Dominant Emery–Dreifuss Muscular Dystrophy (AD‐EDMD) (LGMD1B)
2006-10-01

Autosomal dominant Emery–Dreifuss muscular dystrophy is caused by mutations in the LMNA gene that code for the nuclear membrane protein lamin A/C. We investigated skeletal muscle fibers from several muscles for cytoplasmic degenerative changes in three patients with genetically confirmed Emery–Dreifuss muscular dystrophy. Methods included quantitative light and electron microscopy and PCR‐based mutational analysis. Results: The degenerative pathway was characterized by the gradual replacement of individual myofibers by connective tissue. Early stages of degeneration typically involved only a segment of the cross‐sectional area of a myofiber. Intermediate stages consisted of myofiber shrinkage due to “shedding” of peripheral cytoplasmic portions into the endomysial space, and fragmentation of the myofibers by interposed collagen fibrils. Empty basement membrane sheaths surrounded by abundant deposits of extracellular matrix marked the end stage of the degenerative process. The nuclear number‐to‐cytoplasmic area in myofibers of one patient increased with increasing cross‐sectional area, suggesting that satellite cell fusion with myofibers may have compensated for myofiber shrinkage. The pattern of degeneration described herein differs from muscular dystrophies with plasma membrane defects (dystrophinopathy, dysferlinopathy) and explains the frequently found absence of highly elevated serum creatine kinase levels in autosomal dominant Emery–Dreifuss muscular dystrophy.
The Biosynthetic Gene Clusters of Aminocoumarin Antibiotics
2006-10-01

Plants and microorganisms are the most important sources of secondary metabolites in nature. For research in the functional genomics of secondary metabolism, and for the biotechnological application of such research by genetic engineering and combinatorial biosynthesis, most microorganisms offer a unique advantage to the researcher: the biosynthetic genes for a specific secondary metabolite are not scattered over the genome, but rather are clustered in a well-defined, contiguous region - the biosynthetic gene cluster of that metabolite. This is exemplified in this review for the biosynthetic gene clusters of the aminocoumarin antibiotics novobiocin, clorobiocin and coumermycin A (1), which are potent inhibitors of DNA gyrase. Cloning, sequencing and analysis of the biosynthetic gene clusters of these three antibiotics revealed that the structural differences and similarities of the compounds are perfectly reflected by the genetic organisation of the biosynthetic gene clusters. The function of most biosynthetic genes could be identified by gene inactivation experiments as well as by heterologous expression and biochemical investigation. The prenylated benzoic acid moiety of novobiocin and clorobiocin, involved in the interaction with gyrase, is structurally similar to metabolites found in plants. However, detailed investigations of the biosynthesis revealed that the biosynthetic pathway and the enzymes involved are totally different from those identified in plants.
Familial Retinal Arterial Tortuosity Associated With Tortuosity in Nail Bed Capillaries
2006-10-01

the evaluation for CTX to support early definitive therapy.Moreover, the measurement of cholestanol levels when a subject is initially seen with presenile cataracts of questionable etiology could be a valuable clinical tool.
Simplified detection of microsatellite instability in colorectal cancer without the need for corresponding germline DNA analysis: Figure 1
2006-10-01

A panel of five quasimonomorphic mononucleotide repeats that dispenses with the need to analyse corresponding germline DNA was proposed by Suraweera et al for the detection of high-frequency microsatellite instability (MSI) in colorectal cancer. Using this panel, a simplified and a more sensitive (compared with the original) algorithm (p&lt;0.05) was developed to define the instability of each repeat by assessing the morphological shape of its plot and not its absolute length. 103 cases of colorectal tumours were investigated and the results compared with those obtained by the analysis of five consensus microsatellites (Bethesda reference panel). By the proposed method, a higher specificity, but no loss of sensitivity, was found. Thus, the use of the five mononucleotide repeats in combination with the modified assessment technique simplifies the assessment of MSI, while retaining the sensitivity of the Bethesda panel for the detection of high-frequency MSI.
Challenging the Advanced: Cardiac Surgery without Awareness of a Pheochromocytoma
2006-10-01

We report the case of a 75-year-old male patient who underwent bypass surgery. Intraoperatively unstable hemodynamics with excessive arterial blood pressure was observed. This resulted in the tearing of an anastomosis, which subsequently required hemostasis for repeated bleeding. Postoperatively, laboratory findings and diagnostic imaging confirmed the diagnosis made intraoperatively of a pheochromocytoma. Any surgery without awareness of the possibility of a pheochromocytoma will dramatically increase intraoperative and postoperative morbidity and mortality, especially in cardiac surgery. The uncontrolled release of catecholamines raises arterial blood pressure which can become life-threatening and lead to serious intraoperative complications, as well as cerebrovascular and cardiac comorbidity.
Wasserstoffbrückenbindungen mit Cyanidionen? Die Strukturen von 1,3‐Diisopropyl‐4,5‐dimethylimidazoliumcyanid und 1‐Isopropyl‐3,4,5‐trimethylimidazoliumcyanid
2006-10-01

Abstract Hydrogen Bonds with Cyanide Ions? The Structures of 1,3‐Diisopropyl‐4,5‐dimethylimidazolium Cyanide and 1‐Isopropyl‐3,4,5‐trimethylimidazolium Cyanide 1,3‐Diisopropyl‐4,5‐dimethylimidazolium cyanide ( 2a ) and 1‐isopropyl‐3,4,5‐trimethylimidazolium cyanide ( 2b ) are obtained from the reaction of the corresponding 2,3‐dihydrodimethylimidazol‐2‐ylidenes ( 1 ) and hydrogen cyanide in excellent yield. Their crystal structure analyses reveal the presence of ion pairs linked by hydrogen bonds. The crystal structure analysis of 2a reveals a near colinear orientation of the C(1)‐H bond axis and the cyanide ion while in 2b this orientation is perpendicular. In both cases, the interionic distances are in the expected range for hydrogen bonds. Ab‐initio calculations of the total energy of the salts 2 indicate small differences in energy between the colinear and perpendicular orientation of the ions as well as between the colinear C‐H···C‐N and C‐H···N‐C orientations. The comparison of calculated and measured 13 C and 15 N NMR chemical shifts does not allow the distinction between the possible orientations.
Das neue ternäre Borid Mg8Pt4B und die neue intermetallische Verbindung PtMg2
2006-10-01

Abstract The New Ternary Boride Mg 8 Pt 4 B and the New Intermetallic Compound PtMg 2 The new magnesium platinum boride Mg 8 Pt 4 B was obtained from a reaction of the elements in sealed niobium tubes. It crystallizes isotypically with Mg 8 Rh 4 B in the cubic space group with a =12.2481(1) Å and can be structurally derived from the Ti 2 Ni structure type, where boron occupies cavities, which are formed by four magnesium and four platium atoms. The new intermetallic compound PtMg 2 was also prepared by reaction of the elements in a sealed Nb container and adopts the tetragonal CuAl 2 type structure, space group I 4/ mcm with a = 6.334(1) Å and c = 5.621(1) Å.
Organic Computing at the System on Chip Level
2006-10-01

The evolution of CMOS technologies leads to integrated circuits with ever smaller device sizes, lower supply voltage, higher clock frequency and more process variability. Intermittent faults effecting logic and timing are becoming a major challenge for future integrated circuit designs. This paper presents an organic computing inspired SoC architecture which applies self-organization and self-calibration concepts to build reliable SoCs with lower overheads and a broader fault coverage than classical fault-tolerance techniques. We demonstrate the feasibility of this approach by example on the processing pipeline of a public-domain RISC CPU core
An Automatic Approach to Online Color Training in RoboCup Environments
2006-10-01

Many approaches for extracting landmarks and objects from a camera image based on their color coding were published in the RoboCup domain. They are quite sophisticated and tuned to the typical RoboCup scenario of constant bright lighting using a static subdivision of the color space into different color classes. However, such algorithms would soon be of limited use, as the future requirements of RoboCup include the possibility to play under changing and finally natural lighting. This paper presents an algorithm for automatic online color training, which is able to robustly adapt the mapping of colors to color classes onto different lighting situations online. Using the ACT algorithm a robot will be able to play a RoboCup match while the illumination of the field varies
Abnormal Reactivity of the Primary Somatosensory Cortex During the Experience of Pain in Complex Regional Pain Syndrome: A Magnetoencephalograhic Case Study
2006-10-01

A 49-year-old male worker developed persistent pain in his left wrist after work strain injuries. Clinical symptoms met with criteria for Complex Regional Pain Syndrome (CRPS) type I. In the present study, the effect of the experience of pain on the somatotopy of the primary cortical hand representation was investigated. Somatosensory evoked magnetic fields (SEF) elicited by non-painful tactile stimulation at the index finger of the affected and the unaffected hand were recorded when experiencing pain elicited by a moderate physical load condition (holding a 1.6 kg object in the hand). It was shown that MEG and subjective responses to innocuous tactile stimuli were reduced when simultaneous nociceptive stimulation was applied. These findings suggest a gating effect in the central nervous system elicited by concurrent simultaneous information from two different somatosensory modalities (pain and tactile). The results revealed the existence of nociceptive-induced plastic changes in the central nervous system associated with CRPS type I.
EXOTIC NUCLEAR STRUCTURE PHENOMENA IN MEDIUM MASS NUCLEI
2006-10-01

Large scale nuclear structure studies within the complex Excited Vampir model involving rather large single particle basis systems as well as general two-body interactions are used to investigate exotic phenomena in medium mass nuclei. Results are presented on the influence of Coulomb induced isospin-mixing on the superallowed Fermi β decay in isovector triplets of nuclei, as well as the mechanism responsible for the generation of magnetic bands in the A ≃ 80 mass region.