De novo head and neck cancer after liver transplant with antibody-based immunosuppression induction

Background Powerful antibody-based immunosuppression induction is now used routinely during organ transplantation, and may place patients at even higher risk of post-transplant cancer. Materials and Methods Incidence of de-novo head and neck cancer was extracted from the records of 1685 consecutive adult, deceased donor liver transplant recipients with a minimum 1-year follow-up from 2001 to 2015. There were 121 patients positively identified as having developed de-novo head and neck cancer post-liver transplant. Records of these patients were analyzed to determine demographics, history of cancer pre-liver transplant, de-novo cancer type and location, treatment modalities, and alcohol and tobacco exposure. Results Of the 121 patients who developed cancer of the head and neck (7%), there were 103 cutaneous (6%) and 25 non-cutaneous (1%). For non-cutaneous cancers, factors associated with increased risk of cancer included alcohol abuse (p<0.001), any smoking history (p=0.05), and increasing exposure to tobacco (p<0.01). Ten-year Cox regression patient survival demonstrates a survival disadvantage for patients who develop non-cutaneous cancer (p=0.06), but a survival advantage for patients who develop cutaneous cancer (p<0.01). Conclusions The incidence and pattern of head and neck cancer in this population of liver transplant patients was similar to those published previously, suggesting that induction immunosuppression does not increase risk of these types of cancers. Long term survival was worse for patients with non-cutaneous cancers, but better for those with cutaneous cancers, though the reason is unclear

Equivalent birational embeddings II: divisors

Two divisors in $\P^n$ are said to be Cremona equivalent if there is a Cremona modification sending one to the other. We produce infinitely many non equivalent divisorial embeddings of any variety of dimension at most 14. Then we study the special case of plane curves and rational hypersurfaces. For the latter we characterise surfaces Cremona equivalent to a plane.Comment: v2 Exposition improved, thanks to referee, unconditional characterization of surfaces Cremona equivalent to a plan

Quantum Monte Carlo estimators for the positron-electron annihilation rate in bound and low-energy scattering states

Variational and exact estimators for the positron-electron annihilation rate in bound states of systems containing a positron in the framework of quantum Monte Carlo methods are presented. The modification needed to compute the effective number of electrons Z(eff) when scattering states are concerned is also discussed. The algorithms are tested against four cases for which close to exact results are available, finding an overall good agreement. The systems are Ps(-), PsH, and the s-wave scattering component of e(+)H and e(+)He

ANALYSIS OF CRYPTOGRAPHIC ALGORITHMS AGAINST THEORETICAL AND IMPLEMENTATION ATTACKS

This thesis deals with theoretical and implementation analysis of cryptographic functions. Theoretical attacks exploit weaknesses in the mathematical structure of the cryptographic primitive, while implementation attacks leverage on information obtained by its physical implementation, such as leakage through physically observable parameters (side-channel analysis) or susceptibility to errors (fault analysis). In the area of theoretical cryptanalysis, we analyze the resistance of the Keccak-f permutations to differential cryptanalysis (DC). Keccak-f is used in different cryptographic primitives: Keccak (which defines the NIST standard SHA-3), Ketje and Keyak (which are currently at the third round of the CAESAR competition) and the authenticated encryption function Kravatte. In its basic version, DC makes use of differential trails, i.e. sequences of differences through the rounds of the primitive. The power of trails in attacks can be characterized by their weight. The existence of low-weight trails over all but a few rounds would imply a low resistance with respect to DC. We thus present new techniques to effciently generate all 6-round differential trails in Keccak-f up to a given weight, in order to improve known lower bounds. The limit weight we can reach with these new techniques is very high compared to previous attempts in literature for weakly aligned primitives. This allows us to improve the lower bound on 6 rounds from 74 to 92 for the four largest variants of Keccak-f. This result has been used by the authors of Kravatte to choose the number of rounds in their function. Thanks to their abstraction level, some of our techniques are actually more widely applicable than to Keccak-f. So, we formalize them in a generic way. The presented techniques have been integrated in the KeccakTools and are publicly available. In the area of fault analysis, we present several results on differential fault analysis (DFA) on the block cipher AES. Most DFA attacks exploit faults that modify the intermediate state or round key. Very few examples have been presented, that leverage changes in the sequence of operations by reducing the number of rounds. In this direction, we present four DFA attacks that exploit faults that alter the sequence of operations during the final round. In particular, we show how DFA can be conducted when the main operations that compose the AES round function are corrupted, skipped or repeated during the final round. Another aspect of DFA we analyze is the role of the fault model in attacks. We study it from an information theoretical point of view, showing that the knowledge that the attacker has on the injected fault is fundamental to mount a successful attack. In order to soften the a-priori knowledge on the injection technique needed by the attacker, we present a new approach for DFA based on clustering, called J-DFA. The experimental results show that J-DFA allows to successfully recover the key both in classical DFA scenario and when the model does not perfectly match the faults effect. A peculiar result of this method is that, besides the preferred candidate for the key, it also provides the preferred models for the fault. This is a quite remarkable ability because it furnishes precious information which can be used to analyze, compare and characterize different specific injection techniques on different devices. In the area of side-channel attacks, we improve and extend existing attacks against the RSA algorithm, known as partial key exposure attacks. These attacks on RSA show how it is possible to find the factorization of the modulus from the knowledge of some bits of the private key. We present new partial key exposure attacks when the countermeasure known as exponent blinding is used. We first improve known results for common RSA setting by reducing the number of bits or by simplifying the mathematical analysis. Then we present novel attacks for RSA implemented using the Chinese Remainder Theorem, a scenario that has never been analyzed before in this context

The cone of curves of Fano varieties of coindex four

We classify the cones of curves of Fano varieties of dimension greater or equal than five and (pseudo)index dim X -3, describing the number and type of their extremal rays.Comment: 27 pages; changed the numbering of Theorems, Definitions, Propositions, etc. in accordance with the published version to avoid incorrect reference

Magnon valley Hall effect in CrI3-based vdW heterostructures

Magnonic excitations in the two-dimensional (2D) van der Waals (vdW) ferromagnet CrI3 are studied. We find that bulk magnons exhibit a non-trivial topological band structure without the need for Dzyaloshinskii-Moriya (DM) interaction. This is shown in vdW heterostructures, consisting of single-layer CrI3 on top of different 2D materials as MoTe2, HfS2 and WSe2. We find numerically that the proposed substrates modify substantially the out-of-plane magnetic anisotropy on each sublattice of the CrI3 subsystem. The induced staggered anisotropy, combined with a proper band inversion, leads to the opening of a topological gap of the magnon spectrum. Since the gap is opened non-symmetrically at the K+ and K- points of the Brillouin zone, an imbalance in the magnon population between these two valleys can be created under a driving force. This phenomenon is in close analogy to the so-called valley Hall effect (VHE), and thus termed as magnon valley Hall effect (MVHE). In linear response to a temperature gradient we quantify this effect by the evaluation of the temperature-dependence of the magnon thermal Hall effect. These findings open a different avenue by adding the valley degrees of freedom besides the spin, in the study of magnons

FAKTOR-FAKTOR YANG MEMPENGARUHI KINERJA MANAJEMEN RISIKO PASOKAN DALAM RITEL BUKU DAN ALAT TULIS DI SURABAYA

This study aims to analyze factors which influence risk management performance. Variables which are used, supplier orientation, supplier dependency, customer orientation, and systemic purchasing toward the risk management performance in retail book and stationary at Surabaya. This research uses quantitative approach by using multiple linear regression. The sample of the study is the retail book and stationary at Surabaya. The total sample is 91. Research finding indicates that supplier orientation and supplier dependency give significantly positive effect to risk management performance. While customer orientation and systemic purchasing aren’t significant yet they give positive effect to risk management performance

Salud sexual en Chile: una aproximación descriptiva al comportamiento y la satisfacción sexual de los chilenos

Indexación: Web of Science; Scielo.Antecedentes: El año 2006, la Organización Mundial de la Salud definió a la "salud sexual" como un estado de bienestar físico, emocional, mental y social en relación a la propia sexualidad. De este modo, corresponde a un concepto más amplio que la ausencia de malestares, disfunciones o enfermedades, relacionándose con un nivel de bienestar general. Pese a la relevancia del concepto, aún es escasa la evidencia empírica al respecto a nivel local. Objetivos: El artículo analiza el concepto de "salud sexual" a nivel de población general en Chile. Métodos: Se diseñó una muestra probabilística, polietápica y estratificada en el Gran Santiago, encuestándose a 767 personas mayores de 18 años, siguiendo la metodología de autorreporte de hogares. Resultados: El estudio evidencia diferencias según género y edad en la mayor parte de las variables relativas a la satisfacción sexual y a conductas sexuales seguras. Conclusión: Se concluye que los hombres inician su vida sexual más tempranamente, tienen más parejas sexuales y reportan mayor satisfacción sexual que las mujeres, con excepción de la cohorte más joven. Ellas, a su vez, declaran mayores niveles de protección y cuidado de la vida sexual.Background: In 2006, the World Health Organization endorsed the concept of "sexual health" as a state of physical, emotional, mental and social well-being in relation to sexuality. Thus, it corresponds to a broader concept that the absence of disease, dysfunction or infirmity, being related to a general level of well-being. Despite the relevance of the concept, locally, there is still scarce empirical evidence about it. Aims: The article analyses the concept of "sexual health" among the Chilean general population. Methods: In order to achieve this objective, a probabilistic, polyphasic and stratified sample was designed for the province of Santiago, being surveyed 767 people over 18 years, through a self-reported method in their own households. Results: The study shows differences by gender and age in both sexual satisfaction and safe sexual behaviours. Conclusion: It is possible to conclude that men begin their sexual life earlier, have more sexual partners and report higher sexual satisfaction than women, except for the youngest cohort. Women, in turn, report higherhttp://ref.scielo.org/d57vg