84 research outputs found

    Aging out of the child welfare system in Allegheny County: Descriptive analysis, challenges, and implications

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    National research indicates that 80 percent of youth in foster care leave the child welfare system within six months of their 18th birthday. The reasons for, and implications of, this statistic are myriad. While age 18 was considered at one time to be the age when adulthood began, the transition from childhood to adulthood in American life has become increasingly complex. Youth who age out of the system face ongoing challenges; on average, youth who age out of child welfare systems have lower levels of educational attainment and employment and higher levels of public assistance receipt, juvenile justice involvement, and material hardships than other youth. Programs permitting continued involvement in the system until the age of 21 are increasing in number and scope

    Long-term functional outcome and quality of life following rotationplasty for treatment of malignant tumors

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    Background: Malignant bone tumors of the lower extremity are more frequently found in children and adolescents than in adults. Modern treatment regimens led to high limb salvage rates and offer the choice between endoprosthetic replacement and rotationplasty in many cases. Rotationplasty has proven to be an effective, highly functional option in short-and mid-term studies. Aim of this study was to assess long-term results regarding quality of life and functionality after rotationplasty and to compare the obtained results to a representative healthy German sample cohort. Methods: In total 12 patients who underwent rotationplasty between 1991 and 2001 were enrolled in this study. After physical examination, they were evaluated regarding health related quality of life, functional outcome and psychosocial status. While quality of life was mainly assessed using the SF-36 (The Short Form (36) Health Survey v2),functional outcome was measured using the musculoskeletal tumor society score (MSTS) as well as the Tegner activity level scale. Results: Average age at the time of surgery was 19 +/- 10 year. and 32 +/- 11 year. at the time of follow up. Mean follow-up was 14 +/- 9 years. The SF-36 scores accounted for 80.4 +/- 15.7 regarding physical functioning, for 78.1 +/- 24.1 regarding the physical role functioning, for 74.1 +/- 17.6 regarding bodily pain and for 71.8 +/- 26.1 regarding general health. SF-36 score for vitality was 75.0 +/- 12.8, for social functioning 98.9 +/- 3.6, 88.2 +/- 23.9 for emotional role functioning and 89.6 +/- 10.1 for the mental health. Comparison to a representative German sample cohort revealed significantly higher patient's scores for vitality, social functioning and mental health (p < 0.05). The overall MSTS resulted in an average of 64 +/- 12 % and the Tegner activity level scale accounted for 4.1 +/- 0.6 pts. Conclusions: The presented long-term results indicate that rotationplasty provides a high quality of life. Patients are satisfied with a good functional outcome regarding activities of daily life and even sports

    Improving NFS for the Discrete Logarithm Problem in Non-prime Finite Fields

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    International audienceThe aim of this work is to investigate the hardness of the discrete logarithm problem in fields GF(pn)(p^n) where nn is a small integer greater than 1. Though less studied than the small characteristic case or the prime field case, the difficulty of this problem is at the heart of security evaluations for torus-based and pairing-based cryptography. The best known method for solving this problem is the Number Field Sieve (NFS). A key ingredient in this algorithm is the ability to find good polynomials that define the extension fields used in NFS. We design two new methods for this task, modifying the asymptotic complexity and paving the way for record-breaking computations. We exemplify these results with the computation of discrete logarithms over a field GF(p2)(p^2) whose cardinality is 180 digits (595 bits) long

    Standard‐space atlas of the viscoelastic properties of the human brain

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    Standard anatomical atlases are common in neuroimaging because they facilitate data analyses and comparisons across subjects and studies. The purpose of this study was to develop a standardized human brain atlas based on the physical mechanical properties (i.e., tissue viscoelasticity) of brain tissue using magnetic resonance elastography (MRE). MRE is a phase contrast-based MRI method that quantifies tissue viscoelasticity noninvasively and in vivo thus providing a macroscopic representation of the microstructural constituents of soft biological tissue. The development of standardized brain MRE atlases are therefore beneficial for comparing neural tissue integrity across populations. Data from a large number of healthy, young adults from multiple studies collected using common MRE acquisition and analysis protocols were assembled (N = 134; 78F/ 56 M; 18–35 years). Nonlinear image registration methods were applied to normalize viscoelastic property maps (shear stiffness, μ, and damping ratio, ξ) to the MNI152 standard structural template within the spatial coordinates of the ICBM-152. We find that average MRE brain templates contain emerging and symmetrized anatomical detail. Leveraging the substantial amount of data assembled, we illustrate that subcortical gray matter structures, white matter tracts, and regions of the cerebral cortex exhibit differing mechanical characteristics. Moreover, we report sex differences in viscoelasticity for specific neuroanatomical structures, which has implications for understanding patterns of individual differences in health and disease. These atlases provide reference values for clinical investigations as well as novel biophysical signatures of neuroanatomy. The templates are made openly available (github.com/mechneurolab/mre134) to foster collaboration across research institutions and to support robust cross-center comparisons

    Secure and scalable deduplication of horizontally partitioned health data for privacy-preserving distributed statistical computation

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    Background Techniques have been developed to compute statistics on distributed datasets without revealing private information except the statistical results. However, duplicate records in a distributed dataset may lead to incorrect statistical results. Therefore, to increase the accuracy of the statistical analysis of a distributed dataset, secure deduplication is an important preprocessing step. Methods We designed a secure protocol for the deduplication of horizontally partitioned datasets with deterministic record linkage algorithms. We provided a formal security analysis of the protocol in the presence of semi-honest adversaries. The protocol was implemented and deployed across three microbiology laboratories located in Norway, and we ran experiments on the datasets in which the number of records for each laboratory varied. Experiments were also performed on simulated microbiology datasets and data custodians connected through a local area network. Results The security analysis demonstrated that the protocol protects the privacy of individuals and data custodians under a semi-honest adversarial model. More precisely, the protocol remains secure with the collusion of up to N − 2 corrupt data custodians. The total runtime for the protocol scales linearly with the addition of data custodians and records. One million simulated records distributed across 20 data custodians were deduplicated within 45 s. The experimental results showed that the protocol is more efficient and scalable than previous protocols for the same problem. Conclusions The proposed deduplication protocol is efficient and scalable for practical uses while protecting the privacy of patients and data custodians

    New Assumptions and Efficient Cryptosystems from the ee-th Power Residue Symbol

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    The ee-th power residue symbol (αp)e\left(\frac{\alpha}{\mathfrak{p}}\right)_e is a useful mathematical tool in cryptography, where α\alpha is an integer, p\mathfrak{p} is a prime ideal in the prime factorization of pZ[ζe]p\mathbb{Z}[\zeta_e] with a large prime pp satisfying ep1e \mid p-1, and ζe\zeta_e is an ee-th primitive root of unity. One famous case of the ee-th power symbol is the first semantic secure public key cryptosystem due to Goldwasser and Micali (at STOC 1982). In this paper, we revisit the ee-th power residue symbol and its applications. In particular, we prove that computing the ee-th power residue symbol is equivalent to solving the discrete logarithm problem. By this result, we give a natural extension of the Goldwasser-Micali cryptosystem, where ee is an integer only containing small prime factors. Compared to another extension of the Goldwasser-Micali cryptosystem due to Joye and Libert (at EUROCRYPT 2013), our proposal is more efficient in terms of bandwidth utilization and decryption cost. With a new complexity assumption naturally extended from the one used in the Goldwasser-Micali cryptosystem, our proposal is provable IND-CPA secure. Furthermore, we show that our results on the ee-th power residue symbol can also be used to construct lossy trapdoor functions and circular and leakage resilient public key encryptions with more efficiency and better bandwidth utilization

    Cardiac Alterations in Human African Trypanosomiasis (T.b. gambiense) with Respect to the Disease Stage and Antiparasitic Treatment

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    In Human African Trypanosomiasis (HAT), neurological symptoms dominate and cardiac involvement has been suggested. Because of increasing resistance to the available drugs for HAT, new compounds are desperately needed. Evaluation of cardiotoxicity is one parameter of drug safety, but without knowledge of the baseline heart involvement in HAT, cardiologic findings and drug-induced alterations will be difficult to interpret. The electrocardiogram (ECG) is a tool to evaluate cardiac involvement and the risk of arrythmias. We analysed the ECG of 465 HAT patients and compared them with the ECG of 61 healthy volunteers. In HAT patients the QTc interval was prolonged. This comprises a risk of fatal arrhythmias if new drugs with antiarrhythmic potential will be used. Further, repolarization changes and low voltage were more frequent than in healthy controls. This could be explained by an inflammation of the heart. Treatment of HAT was associated with appearance of repolarization changes but not with a QTc prolongation. These changes appear to be associated with the disease, but not with a specific drug. The main conclusion of this study is that heart involvement is frequent in HAT and mostly well tolerated. However, it can become relevant, if new compounds with antiarrhythmic potential will be used

    Die Behandlung des kongenitalen Tibiadefekts. Eine Analyse von 67 Fällen

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