Committing to quantum resistance: a slow defence for Bitcoin against a fast quantum computing attack

Quantum computers are expected to have a dramatic impact on numerous fields due to their anticipated ability to solve classes of mathematical problems much more efficiently than their classical counterparts. This particularly applies to domains involving integer factorization and discrete logarithms, such as public key cryptography. In this paper, we consider the threats a quantum-capable adversary could impose on Bitcoin, which currently uses the Elliptic Curve Digital Signature Algorithm (ECDSA) to sign transactions. We then propose a simple but slow commit-delay-reveal protocol, which allows users to securely move their funds from old (non-quantum-resistant) outputs to those adhering to a quantum-resistant digital signature scheme. The transition protocol functions even if ECDSA has already been compromised. While our scheme requires modifications to the Bitcoin protocol, these can be implemented as a soft fork.

Histopathological Study on Conservatively Operated Breast Carcinomas

In this histopathological study we looked at 303 cases of breast carcinomas, managed though conservative breast surgery and later analysed with the help of a classical histopathological technique, paraffin embedding. The carcinomas were assessed in terms of tumor size, lymph node status, histological type, correlation between invasive tumors and an situ carcinoma component, resection margins, grading and patients age. Following assessment, we looked at associations between above morphological and clinical parameters and ipsilateral local recurrences. We concluded that more than half of our cases were carcinomas, measuring between 2 cm and 5 cm, with no associated lymph node involvement, in keeping with pTNM criteria for stage II. By far, in our study, the most frequent histopathological type was type NOS (63.37%) followed by invasive lobular carcinoma (10.56%) and mixed ducto-lobular invasive carcinoma (6.27%). Other types of invasive carcinoma were rarer, each representing less than 4% of cases. In regards to in situ carcinomas we noted the most common histological types to be both cribriform intraductal carcinoma and comedocarcinoma, each identified in 1.65% of cases. Amongst invasive breast carcinomas, infiltrating ductal carcinoma not otherwise specified (NOS) was found to be most commonly associated with in situ ductal carcinoma lesions. This was seen in 34.9% of cases, and was the only type associated with an extensive in situ component. Analysing the grading of mammary carcinomas in our study showed that the vast majority of cases (63.04%) were grade 3 tumors. In regards to surgical resection margins, ¾ of cases were noted to have negative margins. Tumor recurrences were noted in 12 cases. These cases were most commonly noted to reoccur following initial poorly differentiated, infiltrating ductal carcinomas, not otherwise specified (NOS), with positive resection margins, measuring less than 2 cm. Patiens tended to be under the age of 40 and had positive lymph nodes. The emergence of local recurrences after conservative surgery for early breast cancer is singnificantly linked to poorly differentiated primary tumors (p <0.05) but not correlated with histological type, presence of extensive intraductal carcinoma component, size of primary breast tumor or lymph node status ( p> 0.05). In terms of increasing the risk of ipsilateral recurrence the most important aspect highlighted in our sudy was the status of the resection margins. Patients with positive resection margins had a significantly high risk to develop recurrences after the conservative surgery, compared to those with negative margins (p <0.001).

Impact of pain in health related quality of life of patients with systemic sclerosis

OBJECTIVES

Systemic sclerosis (SSc) has an heterogenous clinical pattern, with variable organ involvement and degrees of severity. Like in other rheumatic diseases, the self-questionnaires have been used to evaluate SSc globally. The aim of the study is as to evaluate the quality of life (QoL) in patients with either diffuse or limited SSc, and to examine the impact of pain on the QoL scores.

METHODS

Patients with SSc, either diffuse or limited SSc, were included in a cross-sectional study. The QoL was evaluated with the short-form 36 (SF-36) and the functional repercussion with the SSc-modified Health Assessment Questionnaire (S-HAQ).

RESULTS

A total of 89 patients (67 with diffuse and 22 with limited SSc) were included. The SF-36 score values were lower in SSc patients than those reported in the general population. The physical component scores (PCS) of the SF-36 was significantly worse in diffuse compared with limited SSc (P < 0.05). The PCS was significantly negatively related to the number of clinical manifestations (ANOVA, P < 0.0001). The mental component score (MCS) was not influenced by the type of SSc or the number of clinical manifestations presented by the patient. The QoL of SSc patients was highly correlated with pain (R = 0.69) and disability (R = 0.70). Interestingly, the QoL of SSc patients was only slightly correlated with cutaneous (R = 0.42) and pulmonary involvement (R = 0.57).

CONCLUSION

The QoL of patients with SSc is strongly influenced by the type of SSc, the burden of clinical manifestations, the functional disability and by the pain, whatever its cause. The treatment of pain should be considered as priority to improve the QoL of SSc patients.

[Disseminated tuberculosis and profound thrombopenia]

Thrombocytopenia within the context of disseminated tuberculosis can lead to complications requiring rapid treatment. Although the origin is generally central, thrombocytopenia can arise from an immune disorder. We hereby report a case of disseminated tuberculosis associated with thrombocytopenia, which required, in addition to antituberculosis therapy initiated before bacteriological proof, corticosteroid treatment and multiple platelet transfusions. The discovery of anti-platelet antibodies along with the success of immunomodulator therapy confirmed the auto-immune origin of this thrombocytopenia.

181 MOUSE TRIPLETS DEVELOPED FROM SINGLE BLASTOMERES OF AN 8-CELL-STAGE EMBRYO SUPPORTED WITH TETRAPLOID EMBRYOS

Chimera production using altered ES cells became a key tool for generating transgenic mice. However, chimeras are more than just a tool for making mouse mutants; they play a crucial role in analyzing the biological effects of genetic changes. Chimeras can be made by combining two whole 8-cell embryos or by combining subsets of blastomeres of two cleavage stage embryos. Because, at these stages, the early embryonic cells are not yet restricted in their lineage potency, they are equally capable of contributing to the inner cell mass or the trophectoderm. Pluripotency of single blastomeres of the 4-cell and 8-cell mouse embryo has been proved indirectly by aggregating them with carrier blastomers of a different genotype, giving rise to chimeric blastocyst (Tarkowski et al. 1967 J. Embryol. Exp. Morphol. 18, 155-180). In our study we wanted to demonstrate that a single blastomere of an 8-cell stage embryo, supported with tetraploid embryos at the 4-cell stage, is capable of developing into a healthy animal. When tetraploid embryos are used to make chimeras together with diploid cells, tetraploid cells rarely contribute to the embryo itself, but contribute mainly to the primitive endoderm and the trophectoderm, so in this case the newborns will be derived only from the diploid blastomers used (Nagy et al. 1990 Development 110, 815-821). We produced chimeras by aggregating a single blastomere [(2n)(1-cell)] derived by combining sexed, GFP-expressing, diploid 8-cell stage embryo (Hadjantonakis et al. 1998 Nat. Genet. 19, 220-222) with either a sexed diploid 7-cell embryo [(2n)(7-cells)] (one of the 8-cells was taken for sexing) or a non-sexed tetraploid embryo [(4n)(4-cells)]. The aggregates were cultured in vitro and transferred as blastocysts to the uteruses of pseudo-pregnant females. Fetuses were removed by Caesarian section and raised by lactating foster mothers. From the transferred 84 [XY(2n)(1-cell)]/[XX(2n)(7-cells)] aggregates we obtained 12 (14.3%) newborns, 11 (91.7%) males and one (8.3%) female. From the transferred 27 [XY(2n)(1-cell)]/[(4n)(4-cells)] aggregates, where one XY blastomere was combined with a tetraploid embryo, we obtained 7 (25.9%) male newborns: 1 triplet and 2 pairs of twins. We also transferred four [XX(2n)(1-cell)]/[(4n)(4-cells)] chimera embryos, where an XX-blastomere was aggregated with a tetraploid embryo; we obtained a set of living female triplets (75%) from this aggregate. We demonstrated that a single blastomere of the 8-cell-stage embryo is capable of developing into a living newborn. We obtained identical pups from three blastomeres isolated from the same embryo (triplets). This way we produced single blastomere clones and could control the sex of the new generation. This research was supported by grants from OTKA T037582 and RO-1/2002 Intergovernmental S&T cooperation program.

[Cardiopulmonary function before and after cyclophosphamide treatment in severe systemic sclerosis: comparison of monthly intravenous bolus and autologous haematopoietic stem cell transplantation]

PURPOSE

Cyclophosphamide in monthly intravenous bolus is used to treat severe forms of systemic sclerosis with pulmonary involvement. Since 1996, cyclophosphamide therapeutic intensification with autologous haematopoietic stem cells transplantation allowed significant improvement in skin and functional scores in severe systemic sclerosis. Cyclophosphamide potential cardiotoxicity in this setting has been questioned.

METHODS

To analyse cyclophosphamide potential cardiopulmonary toxicity (as graded with WHO classification), we retrospectively studied all severe systemic sclerosis patients treated with cyclophosphamide either during autologous haematopoietic stem cells transplantation procedure (group A) or intravenous cyclophosphamide (group B) recruited in 7 French centers volunteers for the study. Parameters to evaluate heart and lung functions at inclusion, then at last follow-up between 6 and 12 months after start of treatment, were compared using the Mann-Whitney test.

RESULTS

(Mean+/-standard deviation): Groups A (N=14) and B (N=13) were similar at the beginning of the study in terms of skin, renal, heart and lung involvement. Cyclophosphamide total dose (/m(2)) received in group A was superior (P=0.02) to the one in group B. After respective follow-up of 10+/-2.8 (group A) and 9.9+/-2.7 (group B) months, cyclophosphamide cardio toxicity (group A: N=3; group B: N=2), evolution of the left ventricular ejection fraction and arterial and pulmonary pressures did not differ in the two groups.

CONCLUSION

In spite of higher cyclophosphamide doses during autologous haematopoietic stem cells transplantation than bolus treatment, cardiopulmonary toxicity appeared not increased. The ongoing European ASTIS trial will compare the respective benefits of these 2 cyclophosphamide regimens in severe Systemic sclerosis.

Évaluation de la qualité de vie par le MOS-SF36 dans la sclérodermie systémique

OBJECTIVE

To investigate the metric properties and the validity of the Medical Outcome Study Short Form 36 (SF-36), a questionnaire to assess the quality of life, in patients with either diffuse or limited systemic sclerosis (SS), and to examine the effect of the disease on quality of life.

METHODS

Cross sectional study of 86 patients with a SS (64 diffuse SS, 22 limited SS). Disease severity was assessed by clinical examination, pulmonary functional tests and Health Assessment Questionnaire (HAQ) modified for scleroderma.

RESULTS

The SF-36 scores values were lower in diffuse than in limited sclérodermie systémique. The Physical Component Score was worse in patients with than without any clinical involvement. This score increased in relation with the number of clinical involvements. The quality of life of patients with SS was correlated to its functional repercussion.

CONCLUSION

The quality of life in SS patients is correlated with the clinical severity of the disease. The use of SF-36 to measure the quality of life is useful for the clinical evaluation of patients with SS.