julilili42/papers huggingface dataset:
Occlusion handling for medical augmented reality using a volumetric phantom model
2004-11-10

The support of surgical interventions has long been in the focus of application-oriented augmented reality research. Modern methods of surgery, like minimally-invasive procedures, can benefit from the additional information visualization provided by augmented reality. The usability of medical augmented reality depends on a rendering scheme for virtual objects designed to generate easily and quickly understandable augmented views. One important factor for providing such an accessible reality augmentation is the correct handling of the occlusion of virtual objects by real scene elements. The usually large volumetric datasets used in medicine are ill-suited for use as phantom models for static occlusion handling. We present a simple and fast preprocessing pipeline for medical volume datasets which extracts their visual hull volume. The resulting, significantly simplified visual hull iso-surface is used for real-time static occlusion handling in our AR system, which is based on off-the-shelf medical equipment.
CADASIL: underdiagnosed in psychiatric patients?
2004-11-10

Objective: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is exclusively related to symptoms of the central nervous system. Retrospectively in up to 15% the initial presentation is psychiatric disturbances. In these cases the diagnosis often is delayed or missed. Method: Two cases of CADASIL diagnosed in a psychiatric hospital are presented. Results: Both patients were admitted to the gerontopsychiatric department (one because of a suicidal attempt and a depressive episode, the other because of cognitive decline and progressive personal neglect). Brain magnetic resonance imaging (MRI) showed severe leukoencephalopathy in the absence of cardiovascular risk factors. In both cases, diagnosis of CADASIL was made by the identification of specific granular osmiophilic material in skin biopsies. Conclusion: Brain MRI should be performed in all cases of late onset of severe psychiatric symptoms. CADASIL should be considered as a possible differential diagnosis whenever a marked leukoencephalopathy is detectable. Diagnosis can be verified by taking a skin biopsy or by specific genetic testing.
Correlations and spectral functions in asymmetric nuclear matter
2004-11-11

The self-energy of nucleons in asymmetric nuclear matter is evaluated employing different realistic models for the nucleon-nucleon interaction. Starting from the Brueckner Hartree Fock approximation without the usual angle-average in the two-nucleon propagator the effects of the hole-hole contributions are investigated within the self-consistent Green's function approach. Special attention is paid to the isospin-dependence of correlations, which can be deduced from the spectral functions of nucleons in asymmetric matter. The strong components of the proton - neutron interaction lead in neutron-rich matter to a larger depletion for the occupation probability of proton states below the Fermi momentum.
Cognitive differentiation between self, ingroup, and outgroup: The roles of identification and perceived intergroup conflict
2004-11-12

Several models predict that persons ascribe opposite characteristics to self and ingroups on the one hand and outgroups on the other (outgroup contrast). However, only few studies have found this effect. This study explored its boundary conditions. Sixty-two students rated (a) characteristics of themselves, an ingroup (own study major), and an outgroup (other study major), (b) ingroup identification, and (c) perceived intergroup conflict. Participants who were relatively high in ingroup identification and who perceived relatively high levels of intergroup conflict displayed outgroup contrast, as indicated by negative correlations between trait ratings for self and ingroup and between trait ratings for ingroup and outgroup. The other participants showed weaker or no outgroup contrast. Thus, this study is one of the few empirical demonstrations of outgroup contrast and points to moderators that should be considered in future research on this effect. Copyright © 2004 John Wiley & Sons, Ltd.
How to evolve the head-tail pattern from reaction-diffusion systems
2004-11-12

The possible application of evolving artificial embryos to build functional machinery is a promising area of research. Unfortunately, there are still many fundamental problems to be solved before artificial embryology can be applied to such tasks, not to mention the necessary hardware. In this paper we address the problem of how to evolve the head-tail pattern for an artificial embryo endogenously, without predefined asymmetric cell division or external guide through polar cells or exogenous sources of morphogenes. We examine the performance of an evolutionary algorithm on two different fitness functions. Further, we examine the evolvability of several mathematical models for regulatory networks, controlling the behavior of the digital embryo.
Some results on majority quantifiers over words
2004-11-13

The class of languages definable by majority quantifiers using the order predicate is investigated. It is shown that the additional use of first order or counting quantifiers does not increase this class. Further on, addition is in this connection a definable numerical predicate, while the converse does not hold. The emptiness problem for this class turns out to be undecidable.
The Hidden Equilibrium in Aqueous Sodium Carbonate Solutions − Evidence for the Formation of the Dicarbonate Anion
2004-11-15

Abstract Crossover 13 C NMR experiments between [ 13 C]carbonate and [ 18 O]carbonate in aqueous solution confirm the combined action of two oxygen‐exchange modes. The isotopomeric carbon dioxides formed in the hydrolysis equilibrium of the labeled carbonate anions react with hydroxide with formation of hydrogencarbonate and with isotopomeric carbonate anions yielding the corresponding dicarbonate species, which, in the back reaction, form carbon dioxide and carbonate anions with distributed oxygen. (© Wiley‐VCH Verlag GmbH &amp; Co. KGaA, 69451 Weinheim, Germany, 2005)
Business Cycle Volatility in Germany
2004-11-15

Abstract Stylized facts suggest that output volatility in OECD countries has declined in recent years. The causes and the nature of this decline have so far been analyzed mainly for the United States. In this paper, we analyze whether structural changes in output volatility in Germany can be detected. We report evidence that output volatility has declined in Germany. It is difficult to answer the question whether this decline in output volatility reflects good economic and monetary policy or merely ‘good luck’.
Automatic Semantic Activation Is No Myth
2004-11-16

The claim that semantic activation is an automatic process was recently called a myth, on the basis of the finding that if letter search is performed on a prime word, semantic priming effects on response time are eliminated, whereas repetition effects are preserved. The absence of semantic activation, however, cannot be validly inferred from the lack of response time effects, and converging evidence is needed. To this end, we examined the event-related potential correlate of priming, the N400 amplitude modulation, in a letter-search priming paradigm. Our experiment replicated the response time effects and demonstrated that the N400 amplitude successfully differentiates cross-case repetition priming, semantic priming, and neutral conditions. The results clearly indicate that the meaning of the prime word was processed and that semantic activation indeed was present in the letter-search task. The notion that semantic activation is an automatic process should not be abandoned prematurely.
Multiple sequence alignment with user-defined constraints at GOBICS
2004-11-16

Abstract Summary: Most multi-alignment methods are fully automated, i.e. they are based on a fixed set of mathematical rules. For various reasons, such methods may fail to produce biologically meaningful alignments. Herein, we describe a semi-automatic approach to multiple sequence alignment where biological expert knowledge can be used to influence the alignment procedure. The user can specify parts of the sequences that are biologically related to each other; our software program uses these sites as anchor points and creates a multiple alignment respecting these user-defined constraints. By using known functionally, structurally or evolutionarily related positions of the input sequences as anchor points, our method can produce alignments that reflect the true biological relationships among the input sequences more accurately than fully automated procedures can do. Availability: Our software is available online at GÖttingen BIoinformatics Compute Server (GOBICS), http://dialign.gobics.de/anchor/index.php Contact: burkhard@gobics.de
The influence of competition and vaccination on the coexistence of two pneumococcal serotypes
2004-11-16

Streptococcus pneumoniae (pneumococcus) is one of the most important bacterial pathogens and a leading cause of mucosal infections (e.g. otitis media) and various forms of serious diseases (e.g. pneumonia, meningitis, bacteraemia) in developing and developed countries. Based on the polysaccharide capsule, there are at least 90 different pneumococcal serotypes, which may compete with each other to colonize the nasopharynx. Newly developed protein–polysaccharide conjugated vaccines have been shown to provide protection against disease caused by the serotypes included in the vaccine, and also against colonization (carriage). It is feared that yet uncommon, but nonetheless pathogenic serotypes which have been suppressed by competition, may become more prevalent in carriage and disease after large-scale use of conjugate vaccines. In this paper, we use transmission models of pneumococcal carriage to study how competition and vaccination influence the coexistence of two serotypes. According to our results, direct (physical) competition between two pneumococcal serotypes only influences colonization if the duration of naturally acquired immunity is short. By contrast, indirect (antibody-mediated) competition is of influence only if naturally acquired immunity is long lasting. Vaccination reduces the prevalence of the target serotype – an effect that is enforced by the presence of directly competing bacteria. The emergence of a non-target serotype after vaccination is only observed if bacteria compete directly. These results emphasize the importance of studying whether bacteria compete directly or indirectly and for how long people are protected in order to assess the long-term effects of sero-competition.
Electrochemical Sensor Design Using Coplanar and Elevated Interdigitated Array Electrodes. A Computational Study
2004-11-16

Abstract The time dependent diffusion equation for an interdigitated array (IDA) of coplanar and elevated electrodes is solved numerically by extrapolation of the fully implicit method using a problem adapted space grid. The simulations are performed for IDA electrodes in generator‐collector mode. The influence of the electrode height and the height of the diffusion space on the sensitivity and the response time is investigated.
Combination Chemoimmunotherapy Using Alemtuzumab, Fludarabine, Cyclophosphamide, and Doxorubicin (Campath-FCD) Is an Effective First-Line Regimen in Peripheral T-Cell Lymphomas.
2004-11-16

Abstract Peripheral (mature) T-cell lymphomas (PTCL) are represented by distinct lymphoma entities, many of which with a rather unfavourable clinical outcome as compared to B-cell lymphomas. Standard treatment regimens have not been established, except in primary cutaneous T-cell lymphomas (PCTCL). With regard to the unfavourable prognosis we designed a treatment protocol using chemoimmunotherapy in peripheral T-cell lymphomas except PCTCL and ALK-positive large cell anaplastic T-cell lymphomas, consisting of alemtuzumab 3, 10, 30, 30 mg, days 1–4, fludarabine (Flu) 25 mg/m2 days 2–4, cyclophosphamide (CP) 600 mg/m2 day 3, and doxorubicin (Dox) 50 mg/m2 day 4. Included were patients with primary diagnosis or with first or second relapse. Rationales for this regimen were proven efficacy of CP and Dox in T-cell lymphomas, high efficacy of Flu and CP (FC) in other lymphomas and the possible synergism of antibodies with cytotoxic drugs. So far, 23 patients have been included, 18 are evaluable for response and toxicity. Of the latter, 10 patients were diagnosed with PTCL-NOS, 5 with AILD, one with enteropathy-associated T-cell lymphoma, one with NK-cell lymphoma, and one with T-PLL. 9 patients were enrolled with primary diagnosis and 9 patients in relapse. The median age was 60 years (range 21–77); the median non-age adjusted IPI 2.5 (0–4), 2 in patients with primary diagnosis and 3 in patients with relapse. The overall response rate was 61% (11/18). In patients with primary diagnosis the CR rate was 78% (7/9), one patient achieved no change, and one patient died from treatment associated complications before response could be evaluated. All responding patients are in ongoing CR at 2+, 2+, 6+, 11+, 15+,16+, and 17+ months. In the group of relapsed patients one CR and 3 PR (44%) were observed. The main toxicity was leukocytopenia (81% grade III and IV of all evaluable treatment cycles), other grade III and IV toxicities included anemia (18%), thrombocytopenia (39%), infections (18%) nausea/emesis (9%), and allergic reactions (4%). Ten (56%) patients reactivated CMV without CMV-related disease and one patient with suspected CMV-peumonia. In conclusion, this is the first study demonstrating that alemtuzumab can be integrated into a triple-agent chemotherapy regimen. The combination is effective in the first-line treatment of peripheral T-cell lymphomas, however, regarding the general outcome a longer follow-up period of a larger patient population is required.
Salvage Therapy of Progressive and Recurrent Hodgkin’s Disease: Results from a Multicenter Study of the Pediatric DAL/GPOH HD-Study Group.
2004-11-16

Abstract To evaluate the efficacy of a salvage therapy (ST-HD-86) developed for children and adolescents with progressive or relapsed Hodgkin’s disease (HD) who were primarily treated in the pediatric DAL/GPOH studies. The essential chemotherapeutic elements were ifosfamide, etoposide, prednisone (IEP) and doxorubicine, bleomycin, vinblastine, dacarbazine (ABVD). 176 patients with progression (N=51) or first relapse (N=125) were enrolled by 67 centers from six countries between 1986 and 2003. The median time from initial diagnosis to progression/relapse was 1.1 (range, 0.02–17.1) years and the median patients age at the diagnosis of progression/relapse was 14.7 (range, 4.3–24.5) years. Salvage therapy consisted of 3–5 alternating cycles of IEP and ABVD, supplemented in part by 1–2 cycles of cyclophosphamide, vincristine, procarbazine, prednisone (COPP) or CCNU, etoposide, prednimustine (CEP). Radiotherapy was given to involved areas using individualized dosages. In the 1990ies, high-dose high dose chemotherapy with stem cell support was introduced for patients with unfavorable prognostic criteria. Disease-free survival (DFS) and overall survival (OS) at 10 years after initiation of salvage therapy are 63±4% and 74±4%. Second events occurred in 70 of 176 pts (40%). Risk factor analysis revealed the time until progression/relapse as the most discriminating prognostic factor (p=.0001). Patients with progression had an inferior outcome (DFS 41±7%, OS 51±8%), whereas patients with late relapses (&gt;12 months after end of therapy) do very well (DFS 87±4%, OS 90±4%). The result of study ST-HD-86 with a long-term survival of 74% in this large cohort of patients with progressive or relapsed HD can be considered favorable. While the salvage strategy for patients with progression has to be further optimized, a reduction of intensity might be considered for those patients with late relapses following HD in childhood or adolescence.
PCR-Based Liposomal Amphotericin B Treatment Following Allogeneic Stem Cell Transplantation Is a Safe Treatment Strategy: Preliminary Results of a Prospective Study.
2004-11-16

Abstract A prospective randomized multi-center trial was initiated comparing PCR-based preemptive and empirical antifungal therapy with AmBisome in patients after allogeneic stem cell transplantation. A total of 408 patients were randomized at the time of transplant to the antifungal treatment strategy. PCR screening was planned twice weekly during stay in hospital and once weekly after discharge until day 100 post-transplantation. Antifungal prophylaxis consisted of up to 200 mg fluconazole/day. Antifungal therapy was initiated in the PCR group in PCR+ patients with signs of infection and patients with 2 consecutive positive PCR results, and in the empirical treatment group (group B) after 120 hours of febrile neutropenia not responding to broad-spectrum antibacterial therapy. Antifungal treatment consisted of AmBisome at 3 mg/kg for 3 days (loading dose) followed by AmBisome at 1 mg/kg in clinically stable patients, AmBisome at 3 mg/kg was continued in clinically unstable patients. Treatment was stopped according to pre-defined study rules. The two arms were well balanced with regard to age, gender, donor type, underlying disease and stage, and conditioning regimens applied. Out of 403 evaluable patients 196 were randomized to group A and 207 to group B. AmBisome therapy was initiated in 109 patients in group A and in 76 patients in group B (P&lt;0.05). Eleven patients in group A and 16 patients in group B developed proven invasive fungal infections (IFI), overall mortality at 100 and 180 days was not different. Survival curves demonstrated a lower mortality until day 30 post-transplantation for patients receiving PCR-based antifungal therapy with AmBisome (deaths in group A, n=4; group B, n=13; P=0.03). During this early time period when regular PCR-screening was performed, only 1 patient in group A (candidiasis) and 5 patients in group B (invasive aspergillosis, n=1; candidiasis, n=4) succumbed to IFI (P=0.1). This study prospectively compared PCR-based versus empirical antifungal therapy with AmBisome after allogeneic SCT. A reduction in early mortality and a trend for a lower rate of proven invasive fungal infections was documented until day 30 post-transplantation indicating that close fungal PCR monitoring allows to stratify patients at high risk for the subsequent development of invasive fungal infections. Survival at day 100 and 180 post-transplantation was not different.
Single High-Dose Chemoradiotherapy Versus Tandem High Dose Melphalan Followed by Auto-SCT for Advanced Multiple Myeloma. Preliminary Analysissis.
2004-11-16

Abstract The overall survival of patients with advanced MM undergoing high-dose chemotherapy depends mainly on the quality of response. Thus, to improve the response rate, modifications of high dose therapy have been evaluated to prolong survival. In this randomised phase III study 2 strategies to improve response rates were compared: tandem high dose melphalan and an intensified chemoradiotherapy. Tandem high dose chemotherapy was shown to be superior to single high dose chemotherapy in a recent study. In a phase I/II study we showed modified total body irradiation, busulfan and cyclophosphamide to induce a high CR rate (48%). Thus, in this phase III study, tandem high dose melphalan was compared to radiochemotherapy with TMI/Bu/Cy. 294 patients with age Thus, the higher organ toxicity following the intensified conditioning regimen does not result in a higher TRM when compared to tandem-melphalan. With a still short follow up of 4 years no significant difference in PFS is demonstrated between a single course of high dose chemoradiotherapy and tandem high dose melphalan therapy.
Sphingosine 1-Phosphate (S1P) Is a Chemotactic Factor for CD34+ Progenitors and CD34+ Cell Lines Expressing the S1P1 Receptor: Possible Contribution to Progenitor Cell Trafficking.
2004-11-16

Abstract Trafficking of hematopoietic stem and progenitor cells (HPC) is controlled by G protein coupled receptors (GPRs), particularly by the chemokine receptor CXCR4. However, homing of HPC does not exclusively depend on CXCR4 and its ligand SDF-1. In addition to chemokine receptors, also GPRs for non-peptide lipid mediators may be involved in HPC migration. In the present study, we demonstrate that sphingosine 1-phosphate (S1P) is chemotactic for human CD34+ HPC (optimum dose 5 μM), as measured in a modified Boyden chamber system. In CD34+ cell lines, the chemotactic response was even stronger and occurred at lower S1P concentrations (e.g., optimum dose 100 nM for Jurkat cells, 2-fold stronger migration compared to HPC). By RT-PCR, we measured mRNA expression of the 5 different S1P receptors (S1P1,2,3,4,5). All CD34+ hematopoietic cell lines analyzed (KG1, KG1a, Jurkat) expressed S1P1, a S1P receptor with known chemotactic activity, while CD34- cell lines (HL-60, THP-1) were negative for S1P1. In HL-60 cells, chemotaxis in response to S1P was even reduced compared to spontaneous migration, which might be due to the expression of S1P receptors other than S1P1 with known inhibitory effects, particularly S1P2. In mobilized peripheral blood CD34+ progenitor cells from different donors, S1P1 was consistently expressed in both CD34+CD38+ and more primitive CD34+CD38- HPC, while expression of S1P2,3,4,5 was variable. S1P induced also other typical responses of GPR-mediated signaling in CD34+ cell lines and HPC, such as polymerization of filamentous actin, as measured by flow cytometry after labeling of the cells with FITC-phalloidin. We conclude that S1P is a chemotactic factor for CD34+ HPC and CD34+ cell lines due to expression of the GPR S1P1. As megakaryocytes and platelets represent an abundant source of S1P in the bone marrow, our results suggest that S1P and its receptor S1P1 may contribute to trafficking and spatial distribution of HPC in the hematopoietic microenvironment.