Chondrosarcoma of the Chest Wall: A Review of 53 Cases from Two Institutions

Background/Aim: Chondrosarcomas (CS) of the chest wall are rare, but present an aggressive biological behavior compared to CS of the extremities. The aims of the present study were to determine factors associated with oncological outcomes as well as complications. Patients and Methods: We retrospectively analyzed 53 patients (42 primary, 11 recurrent tumors). In total, 39 central CS, 10 peripheral CS, 3 dedifferentiated CS and 1 mesenchymal CS were included. The ribs were most commonly affected (68%). Overall survival and disease-free survival were estimated with Kaplan-Meier analyses and compared with log-rank test. Results: Mean follow-up was 7 years. Negative margins were achieved in 87% of patients. Thirty patients (57%) remained continuously disease-free (NED), three (5%) NED after treatment of relapse, seven (13%) were alive with disease, twelve (23%) were dead with disease and one of other cause. The 10-year survival rate was 81% and 45% in primary and recurrent tumors, respectively. Survival was significantly affected by tumor stage (p<0.001), local recurrence (p=0.025) and metastases (p=0.002). Six complications (16%) were observed. Conclusion: The outcome is rather poor, especially in patients with local recurrence. Presumably due to a high biological aggressiveness, a stricter definition of surgical margins should be considered for this location

Report of the FELASA-EFAT Working Group

Publisher Copyright: © The Author(s) 2023.Competent, confident and caring laboratory animal caretakers, technicians and technologists (LAS staff) are vital for good animal welfare, high-quality science and a secure Culture of Care. This requires high-quality education, training, supervision and continuing professional development (CPD) of LAS staff. However, there is a lack of harmonisation regarding how this education and training is conducted among European countries, and nor are there recommendations adapted to Directive 2010/63/EU. Therefore, FELASA and EFAT established a working group with the task of establishing recommendations for education, training and CPD for LAS staff. The working group established five different levels (LAS staff levels 0–4), defining the required level of competence and attitude, as well as suggesting educational requirements for reaching each level. Defining these levels should help to ensure that appropriate educational and CPD activities are in place, and to enable employers and LAS staff to determine the level and career stage attained. Furthermore, proper assessment of competencies and effective CPD schemes for all relevant staff should be established. Regulators should support this by setting standards for competence assessment and ensuring that they are consistently applied. In addition, establishments should involve the LAS staff in defining and developing the Culture of Care. The Animal Welfare Body should be involved and have oversight of education, training and CPD. These recommendations will contribute to harmonisation and increased quality of education, training and CPD, as well as provide clearer career pathways for LAS staff, helping to ensure high standards of animal welfare and science.publishersversionepub_ahead_of_prin

Fooling primality tests on smartcards

We analyse whether the smartcards of the JavaCard platform correctly validate primality of domain parameters. The work is inspired by the paper Prime and prejudice: primality testing under adversarial conditions, where the authors analysed many open-source libraries and constructed pseudoprimes fooling the primality testing functions. However, in the case of smartcards, often there is no way to invoke the primality test directly, so we trigger it by replacing (EC)DSA and (EC)DH prime domain parameters by adversarial composites. Such a replacement results in vulnerability to Pohlig-Hellman style attacks, leading to private key recovery. Out of nine smartcards (produced by five major manufacturers) we tested, all but one have no primality test in parameter validation. As the JavaCard platform provides no public primality testing API, the problem cannot be fixed by an extra parameter check, %an additional check before the parameters are passed to existing (EC)DSA and (EC)DH functions, making it difficult to mitigate in already deployed smartcards

Counting points on hyperelliptic curves over finite fields

International audienceWe describe some algorithms for computing the cardinality of hyperelliptic curves and their Jacobians over finite fields. They include several methods for obtaining the result modulo small primes and prime powers, in particular an algorithm à la Schoof for genus 2 using Cantor's division polynomials. These are combined with a birthday paradox algorithm to calculate the cardinality. Our methods are practical and we give actual results computed using our current implementation. The Jacobian groups we handle are larger than those previously reported in the literature

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

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

A heuristic quasi-polynomial algorithm for discrete logarithm in finite fields of small characteristic

International audienceIn the present work, we present a new discrete logarithm algorithm, in the same vein as in recent works by Joux, using an asymptotically more efficient descent approach. The main result gives a quasi-polynomial heuristic complexity for the discrete logarithm problem in finite field of small characteristic. By quasi-polynomial, we mean a complexity of type $n^{O(\log n)}$ where $n$ is the bit-size of the cardinality of the finite field. Such a complexity is smaller than any $L(\varepsilon)$ for $\epsilon>0$. It remains super-polynomial in the size of the input, but offers a major asymptotic improvement compared to $L(1/4+o(1))$

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

The $e$-th power residue symbol $\left(\frac{\alpha}{\mathfrak{p}}\right)_e$ is a useful mathematical tool in cryptography, where $\alpha$ is an integer, $\mathfrak{p}$ is a prime ideal in the prime factorization of $p\mathbb{Z}[\zeta_e]$ with a large prime $p$ satisfying $e \mid p-1$, and $\zeta_e$ is an $e$-th primitive root of unity. One famous case of the $e$-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 $e$-th power residue symbol and its applications. In particular, we prove that computing the $e$-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 $e$ 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 $e$-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

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

Tight Reductions for Diffie-Hellman Variants in the Algebraic Group Model

Fuchsbauer, Kiltz, and Loss~(Crypto\u2718) gave a simple and clean definition of an ¥emph{algebraic group model~(AGM)} that lies in between the standard model and the generic group model~(GGM). Specifically, an algebraic adversary is able to exploit group-specific structures as the standard model while the AGM successfully provides meaningful hardness results as the GGM. As an application of the AGM, they show a tight computational equivalence between the computing Diffie-Hellman~(CDH) assumption and the discrete logarithm~(DL) assumption. For the purpose, they used the square Diffie-Hellman assumption as a bridge, i.e., they first proved the equivalence between the DL assumption and the square Diffie-Hellman assumption, then used the known equivalence between the square Diffie-Hellman assumption and the CDH assumption. In this paper, we provide an alternative proof that directly shows the tight equivalence between the DL assumption and the CDH assumption. The crucial benefit of the direct reduction is that we can easily extend the approach to variants of the CDH assumption, e.g., the bilinear Diffie-Hellman assumption. Indeed, we show several tight computational equivalences and discuss applicabilities of our techniques