LLukas22/scidocs huggingface dataset:
Sybil Guard: Defending Against Sybil Attacks via Social Networks

Peer-to-peer and other decentralized, distributed systems are known to be particularly vulnerable to Sybil attacks. In a Sybil attack, a malicious user obtains multiple fake identities and pretends to be multiple, distinct nodes in the system. By controlling a large fraction of the nodes in the system, the malicious user is able to ―out vote‖ the honest users in collaborative tasks such as Byzantine failure defenses. This paper presents Sybil Guard, a novel protocol for limiting the corruptive influences of Sybil attacks. Our protocol is based on the ―social network‖ among user identities, where an edge between two identities indicates a human-established trust relationship. Malicious users can create many identities but few trust relationships. Thus, there is a disproportionately-small ―cut‖ in the graph between the Sybil nodes and the honest nodes. Sybil Guard exploits this property to bound the number of identities a malicious user can create. We show the effectiveness of Sybil Guard both analytically and experimentally.
The use of intraarticular tramadol for postoperative analgesia after arthroscopic knee surgery: a comparison of different intraarticular and intravenous doses

We aimed to determine the optimal dose of tramadol when administered intraarticularly after arthroscopic knee surgery under general anesthesia in patients with an American Society of Anesthesiologists (ASA) physical status score of I-II. When the surgical procedure was completed, patients were assigned to one of seven groups (n=30 for each) in a double-blinded and randomized manner according to a table of random numbers. Group I received 100 mg tramadol, Group II received 50 mg tramadol, Group III received 20 mg tramadol and Group IV received 0.9% NaCl intraarticularly in 20 ml solutions. Group V received 100 mg tramadol, Group VI received 50 mg tramadol and Group VII received 20 mg tramadol intravenously. Pain was evaluated by using the Visual Analogue Scale (VAS) at 0 min (when the patient was cooperated after extubation), 30 min, 1 h, 4 h, 6 h, 12 h, 18 h and 24 h postoperatively. Patients were administered diclofenac sodium 75 mg intravenously (i.m.) when they experienced pain. The intraarticular tramadol groups had longer duration of analgesia than i.v. tramadol groups who were administered the same doses (I vs V; II vs VI; III vs VII; p <0.001). Group I had the longest duration of analgesia (p<0.001). Group II had a longer time to the first analgesic request than all other groups (p<0.001) except Group I. Consequently, Group I and II needed less analgesics than other groups (p<0.001). Pain scores were 0–3 on the VAS in Groups I, II and V at first assessment, in Groups I and II at 30 min and 1 h, and in Group I at 4 h and 6 h postoperatively (p<0.01). In Group V, vomiting was more a more frequent complication than with other groups (p<0.05). It is concluded that tramadol provides analgesia with a peripheral mechanism when administered intraarticularly. The side effects of intraarticular 100 mg tramadol were no more severe than those for intraarticular 50 mg tramadol. Moreover, intraarticular 100 mg tramadol provided excellent analgesia after arthroscopic surgery.
Effects of contrast material on computed tomographic measurements of lung volumes in patients with acute lung injury

BACKGROUND
Intravenous injection of contrast material is routinely performed in order to differentiate nonaerated lung parenchyma from pleural effusion in critically ill patients undergoing thoracic computed tomography (CT). The aim of the present study was to evaluate the effects of contrast material on CT measurement of lung volumes in 14 patients with acute lung injury.


METHOD
A spiral thoracic CT scan, consisting of contiguous axial sections of 10 mm thickness, was performed from the apex to the diaphragm at end-expiration both before and 30 s (group 1; n = 7) or 15 min (group 2; n = 7) after injection of 80 ml contrast material. Volumes of gas and tissue, and volumic distribution of CT attenuations were measured before and after injection using specially designed software (Lungview; Institut National des Télécommunications, Evry, France). The maximal artifactual increase in lung tissue resulting from a hypothetical leakage within the lung of the 80 ml contrast material was calculated.


RESULTS
Injection of contrast material significantly increased the apparent volume of lung tissue by 83 +/- 57 ml in group 1 and 102 +/- 80 ml in group 2, whereas the corresponding maximal artifactual increases in lung tissue were 42 +/- 52 ml and 31 +/- 18 ml.


CONCLUSION
Because systematic injection of contrast material increases the amount of extravascular lung water in patients with acute lung injury, it seems prudent to avoid this procedure in critically ill patients undergoing a thoracic CT scan and to reserve its use for specific indications.
Association of ocular disease and mortality in a diabetic population.

OBJECTIVE
To investigate the association of ocular disease with all-cause and cause-specific mortality in a diabetic population.


DESIGN
Geographically defined population-based cohort study.


SETTING
An 11-county area in Wisconsin.


STUDY POPULATION
Participants were all younger-onset diabetic persons (diagnosed as having diabetes at <30 years of age and taking insulin) and a random sample of older-onset diabetic persons (diagnosed as having diabetes at > or =30 years of age). Diabetic retinopathy, macular edema, visual acuity, and cataract were measured using standardized protocols at baseline examinations from 1980 to 1982, in which 996 younger-onset and 1370 older-onset persons participated. Participants were followed up for 16 years.


MAIN OUTCOME MEASURE
All-cause and cause-specific mortality as determined from death certificates.


RESULTS
In the younger-onset group, after controlling for age and sex, retinopathy severity, macular edema, cataract, history of cataract surgery, and history of glaucoma at baseline were associated with all-cause and ischemic heart disease mortality. In the older-onset group, after controlling for age and sex, retinopathy and visual impairment were related to all-cause, ischemic heart disease, and stroke mortality. No ocular variable under study was related to cancer mortality in the older-onset group. After controlling for systemic risk factors, visual impairment was associated with all-cause and ischemic heart disease mortality in the younger-onset group. In the older-onset group, retinopathy severity was related to all-cause and stroke mortality, and visual impairment was related to all-cause, ischemic heart disease, and stroke mortality.


CONCLUSIONS
Presence of more severe retinopathy or visual impairment in diabetic patients is a risk indicator for increased risk of ischemic heart disease death. Presence of these ocular conditions may identify individuals who should be under care for cardiovascular disease.
The Seattle Heart Failure Model predicts survival in patients with cardiac resynchronization therapy: a validation study.

BACKGROUND
The Seattle Heart Failure Model (SHFM) predicts mortality in patients with heart failure, but no study has investigated model performance in subjects with cardiac resynchronization therapy (CRT).


METHODS AND RESULTS
Prospectively collected registry data of 427 patients with CRT were used for the evaluation of the discrimination and calibration performance of the SHFM. The primary end point was all-cause mortality. Calibration profile was assessed with the use of Hosmer-Lemeshow tests, and discrimination was assessed by calculating areas under receiver operating characteristic curves (AUCs) derived from the model. Mean (SD) age of the study population was 61.2 (11.1) years (72.6% male). During a median follow-up of 24.7 months, 16.9% (72/427) of the patients reached the primary end point, with observed outcomes of 34/303, 54/234, and 72/97 at years 1, 2, and 5, respectively. No evidence of insufficient fit was found in any calibration tests. AUC estimates in all subjects were 0.7377 (95% CI 0.6575-0.8179) at year 1, 0.7936 (95% CI 0.7317-0.8556) at year 2, and 0.7572 (95% CI 0.6455-0.8689) at year 5.


CONCLUSIONS
SHFM offers an accurate prediction of survival in patients with CRT, with good observed calibration and AUC estimates indicating discrimination performance similar to those found by earlier validation studies.
Fast correspondence search for 3 D surface matching

An algorithm for least squares matching of overlapping 3D surfaces is presented. It estimates the transformation parameters between two or more fully 3D surfaces, using the Generalized Gauss-Markoff model, minimizing the sum of squares of the Euclidean distances between the surfaces. This formulation gives the opportunity of matching arbitrarily oriented 3D surfaces simultaneously, without using explicit tie points. Besides the mathematical model and execution aspects we pay particular interest to the reduction of the computational expenses. An efficient space partitioning method is implemented in order to speed up the correspondence search, which is the main portion of the computational efforts. The simultaneous matching of sub-surface patches is given as another strategy. It provides a computationally effective solution, since it matches only relevant multi-subpatches rather then the whole overlapping area. A practical example including computation times is given for the demonstration of the method. * Corresponding author. http://www.photogrammetry.ethz.ch
Quantum Gravity as Sum over Spacetimes

A major unsolved problem in theoretical physics is to reconcile the classical theory of general relativity with quantum mechanics. These lectures will deal with an attempt to describe quantum gravity as a path integral over geometries. Such an approach has to be non-perturbative since gravity is a non-renormalizable quantum field theory when the dimension of spacetime is four.
A trial of antiparasitic treatment to reduce the rate of seizures due to cerebral cysticercosis.

BACKGROUND
Neurocysticercosis is the main cause of adult-onset seizures in the developing world. Whether therapy with antiparasitic agents results in improved seizure control has been questioned because of the lack of adequate, controlled studies.


METHODS
We conducted a double-blind, placebo-controlled trial in which 120 patients who had living cysticerci in the brain and seizures treated with antiepileptic drugs were randomly assigned to receive either 800 mg of albendazole per day and 6 mg of dexamethasone per day for 10 days (60 patients) or two placebos (60 patients). The patients were followed for 30 months or until they had been seizure-free for 6 months after the doses of the antiepileptic drugs had been tapered. The efficacy of treatment was measured as the decrease in the number of seizures after treatment.


RESULTS
In the albendazole group, there was a 46 percent reduction in the number of seizures (95 percent confidence interval, -74 to 83 percent) during months 2 to 30 after treatment. This reduction, which was not statistically significant, was composed of a nonsignificant reduction of 41 percent in the number of partial seizures (95 percent confidence interval, -124 to 84 percent) and a significant 67 percent reduction in the number of seizures with generalization (95 percent confidence interval, 20 to 86 percent). Most of the difference in the number of partial seizures was attributable to a few patients who had many seizures during follow-up. The proportions of patients who had partial seizures during follow-up were similar in the two groups (19 of 57 in the albendazole group and 16 of 59 in the placebo group), but the patients in the placebo group had a greater tendency to have seizures with generalization (22 of 59, vs. 13 of 57 in the albendazole group; risk ratio, 1.63; 95 percent confidence interval, 0.91 to 2.92). More of the intracranial cystic lesions resolved in the albendazole group than in the placebo group. With the sole exception of abdominal pain, side effects did not differ significantly between the two groups.


CONCLUSIONS
In patients with seizures due to viable parenchymal cysts, antiparasitic therapy decreases the burden of parasites and is safe and effective, at least in reducing the number of seizures with generalization.
Methods for Sentence Compression

Sentence compression is the task of producing a summary of a single sentence. The compressed sentence should be shorter, contain the important content from the original, and itself be grammatical. The three papers discussed here take different approaches to identifying important content, determining which sentences are grammatical, and jointly optimizing these objectives. One family of approaches we will discuss is those that are tree-based, which create a compressed sentence by making edits to the syntactic tree of the original sentence. A second type of approach is sentence-based, which generates strings directly. Orthogonal to either of these two approaches is whether sentences are treated in isolation or if the surrounding discourse affects compressions. We compare a tree-based, a sentence-based, and a discourse-based approach and conclude with ideas for future work in this area. Comments University of Pennsylvania Department of Computer and Information Science Technical Report No. MSCIS-10-20. This technical report is available at ScholarlyCommons: http://repository.upenn.edu/cis_reports/929 Methods for Sentence Compression
Patient journey after admission for acute heart failure: length of stay, 30-day readmission and 90-day mortality.

AIMS
The course of patients following admission for acute heart failure (AHF) is of major importance to patients and healthcare providers. We examined predictors and associations of length of stay (LOS), 30-day post-discharge readmission and 90-day post-discharge mortality in 1990 patients enrolled in the PROTECT study.


METHODS AND RESULTS
PROTECT was a randomized study that examined the effect of the adenosine blocker rolofylline in patients within 24 h of admission for AHF with mild to moderate renal impairment. Geographic-region-adjusted multivariable models showed that LOS was only partly explained by the severity of heart failure (HF), comorbidities (diabetes mellitus, renal impairment, ischaemic heart disease) and degree of metabolic dysfunction (cholesterol and albumin) at baseline (adjusted R(2) 0.27). Addition of in-hospital worsening heart failure (WHF) and changes in metabolic markers contributed significantly to prediction of LOS [R(2) difference 0.050, 95% confidence interval (CI) 0.0282-0.072]. Thirty-day HF readmission was associated with more severe HF and previous HF admission but not with LOS (odds ratios 1.00, 95% CI 0.97-1.04). Death within 90 days after discharge was associated with older age, more severe HF, worse renal function, and lower sodium and bicarbonate at admission; LOS was a strong predictor of 90-day post-discharge mortality.


CONCLUSIONS
In patients admitted for AHF, LOS is not well-predicted by traditional markers of disease severity, but strongly associated with the occurrence of in-hospital WHF. Longer LOS is a strong predictor of early mortality after discharge but not of readmission. These findings may help focus efforts to reduce LOS and post-discharge outcomes on patients' subgroups at increased risk.
Youth Unemployment in Korea : From a German and Transitional Labour Market Point of View

Youth Unemployment in Korea: From a German and Transitional Labour Market Point of View By conventional statistics, youth unemployment seems to be quite moderate in Korea: ‘only’ 9.6 percent of the ‘active’ youth labour force was unemployed compared to 21.4 percent in EU-27 in 2011. Germany, with a youth unemployment rate of 8.5 percent, is one of the very few European countries outperforming Korea. But the Korean case is in one respect unusual. From the perspective of intergenerational risk sharing Korea’s youth unemployment rate is 4.6 times higher than the unemployment rate of adults aged 45 to 54; in Germany, this figure is only 1.7. Further peculiarities come up if unemployment is measured by the number of youth not in employment, education or training (NEET) in percent of the total youth population. Korea’s NEET figures are at the top in OECD countries, especially for youth with tertiary education. This paper throws some light to explain this conundrum: It sketches, first, the main causes of youth unemployment and the general policy interventions; because a large part of the problem is structural, possible immediate measures to avoid long-term scar effects for the unemployed youth are briefly reviewed; differences between Europe and the United States show in particular the importance of automatic stabilizers like unemployment insurance in order to reduce the pressure on unfavourable risk sharing for youth in times of recession. The main part is devoted to possible lessons for Korea from Europe, in particular from Germany. Dual education and vocational training systems that emphasise middle level and market oriented skills are identified as institutional device both for fairer intergenerational risk sharing as well as for a smoother transition from school to work. In its outlook, the paper comes back to the puzzle of highly and academically inflated youth unemployment by referring to a possible hidden cause in Korea: A strong insurance motive might explain the overall striving for an academic degree inducing not only wasteful congestion at labour market entries but also unfair job allocation through credentialism. JEL Classification: E24, I24, J64
Prioritizing performance measurement for emergency department care: consensus on evidence-based quality of care indicators.

BACKGROUND
The evaluation of emergency department (ED) quality of care is hampered by the absence of consensus on appropriate measures. We sought to develop a consensus on a prioritized and parsimonious set of evidence-based quality of care indicators for EDs.


METHODS
The process was led by a nationally representative steering committee and expert panel (representatives from hospital administration, emergency medicine, health information, government, and provincial quality councils). A comprehensive review of the scientific literature was conducted to identify candidate indicators. The expert panel reviewed candidate indicators in a modified Delphi panel process using electronic surveys; final decisions on inclusion of indicators were made by the steering committee in a guided nominal group process with facilitated discussion. Indicators in the final set were ranked based on their priority for measurement. A gap analysis identified areas where future indicator development is needed. A feasibility study of measuring the final set of indicators using current Canadian administrative databases was conducted.


RESULTS
A total of 170 candidate indicators were generated from the literature; these were assessed based on scientific soundness and their relevance or importance. Using predefined scoring criteria in two rounds of surveys, indicators were coded as "retained" (53), "discarded" (78), or "borderline" (39). A final set of 48 retained indicators was selected and grouped in nine categories (patient satisfaction, ED operations, patient safety, pain management, pediatrics, cardiac conditions, respiratory conditions, stroke, and sepsis or infection). Gap analysis suggested the need for new indicators in patient satisfaction, a healthy workplace, mental health and addiction, elder care, and community-hospital integration. Feasibility analysis found that 13 of 48 indicators (27%) can be measured using existing national administrative databases.


DISCUSSION
A broadly representative modified Delphi panel process resulted in a consensus on a set of 48 evidence-based quality of care indicators for EDs. Future work is required to generate technical definitions to enable the uptake of these indicators to support benchmarking, quality improvement, and accountability efforts.
A Formal Syntax of Natural Languages and the Deductive Grammar

Streszczenie.This paper presents a formal syntax framework of natural languages for computational linguistics. The abstract syntax of natural languages, particularly English, and their formal manipulations are described. On the basis of the abstract syntax, a universal language processing model and the deductive grammar of English are developed toward the formalization of Chomsky’s universal grammar in linguistics. Comparative analyses of natural and programming languages, as well as the linguistic perception on software engineering, are discussed. A wide range of applications of the deductive grammar of English have been explored in language acquisition, comprehension, generation, and processing in cognitive informatics, computational intelligence, and cognitive computing.
The FimH Gene in Uropathogenic Escherichia coli Strains Isolated From Patients With Urinary Tract Infection

BACKGROUND
Urinary tract infections (UTIs) are one of main health problems caused by many microorganisms, including uropathogenic Escherichia coli (UPEC). UPEC strains are the most frequent pathogens responsible for 85% and 50% of community and hospital acquired UTIs, respectively. UPEC strains have special virulence factors, including type 1 fimbriae, which can result in worsening of UTIs.


OBJECTIVES
This study was performed to detect type 1 fimbriae (the FimH gene) among UPEC strains by molecular method.


MATERIALS AND METHODS
A total of 140 isolated E. coli strains from patients with UTI were identified using biochemical tests and then evaluated for the FimH gene by polymerase chain reaction (PCR) analysis.


RESULTS
The UPEC isolates were identified using biochemical tests and were screened by PCR. The fimH gene was amplified using specific primers and showed a band about 164 bp. The FimH gene was found in 130 isolates (92.8%) of the UPEC strains. Of 130 isolates positive for the FimH gene, 62 (47.7%) and 68 (52.3%) belonged to hospitalized patients and outpatients, respectively.


CONCLUSIONS
The results of this study indicated that more than 90% of E. coli isolates harbored the FimH gene. The high binding ability of FimH could result in the increased pathogenicity of E. coli; thus, FimH could be used as a possible diagnostic marker and/or vaccine candidate.
Computational origami: from flapping birds to space telescopes

In this paper, I discuss developments in computational origami, the application of computation geometry to the creation of art and technology. Origami, the Japanese art of paperfolding, is a tightly constrained art form (one sheet, no cuts in the most common form) and techniques and concepts from CG have revolutionized the art and have led to remarkable practical applications.