Issues and Observations on Applications of the Constrained-Path Monte Carlo Method to Many-Fermion Systems

We report several important observations that underscore the distinctions between the constrained-path Monte Carlo method and the continuum and lattice versions of the fixed-node method. The main distinctions stem from the differences in the state space in which the random walk occurs and in the manner in which the random walkers are constrained. One consequence is that in the constrained-path method the so-called mixed estimator for the energy is not an upper bound to the exact energy, as previously claimed. Several ways of producing an energy upper bound are given, and relevant methodological aspects are illustrated with simple examples.Comment: 28 pages, REVTEX, 5 ps figure

Correlated Wave-Functions and the Absence of Long Range Order in Numerical Studies of the Hubbard Model

We present a formulation of the Constrained Path Monte Carlo (CPMC) method for fermions that uses trial wave-functions that include many-body effects. This new formulation allows us to implement a whole family of generalized mean-field states as constraints. As an example, we calculated superconducting pairing correlation functions for the two-dimensional repulsive Hubbard model using a BCS trial state as the constraint. We compared the results with the case where a free-electron trial wave-function is used. We found that the correlation functions are independent of which state is used as the constraint, which reaffirms the results previously found by Zhang et. al regarding the suppression of long range pairing correlations as the system size increases.Comment: 15 pages, 3 figures, submitted to Phys. Rev.

Type-Specific Identification of Genital Human Papillomavirus Infection in Women with Cytological Abnormality

Objectives: To estimate the frequency of human papillomavirus (HPV) infection and the genotype distribution of HPV among women with a Pap smear showing atypical squamous cells of undetermined significance (ASC-US) attending the Program for the Detection and Control of Cervical Cancer in Bogotá, Colombia. Study Design: Cervical samples from 200 women with an ASC-US Pap smear were analyzed for the presence of HPV DNA and genotype distribution using a commercial molecular technique (Linear Array®; Roche Molecular Systems, USA). Results: HPV infection was found in 140 women (70%). High-risk HPV types were present in 46.4% of the samples; 16.4% showed a low-risk HPV type, and 37.1% showed both. Of the positive samples, 42.9% were infected with a single viral genotype, whereas 57.1% exhibited multiple HPV infections. The most common HPV genotypes were HPV 16, 53, and 52 with a prevalence of 26.4, 16.4, and 13.6%, respectively. Conclusion: The epidemiological characterization of HPV infections described in this study might guide actions for epidemiological surveillance to strengthen the program in Bogotá and to develop appropriate HPV vaccination programs.Instituto de Genética Veterinari

Quantum Algorithms for Fermionic Simulations

We investigate the simulation of fermionic systems on a quantum computer. We show in detail how quantum computers avoid the dynamical sign problem present in classical simulations of these systems, therefore reducing a problem believed to be of exponential complexity into one of polynomial complexity. The key to our demonstration is the spin-particle connection (or generalized Jordan-Wigner transformation) that allows exact algebraic invertible mappings of operators with different statistical properties. We give an explicit implementation of a simple problem using a quantum computer based on standard qubits.Comment: 38 pages, 2 psfigur

Effective nephroprotection against acute kidney injury with a star-shaped polyglutamate-curcuminoid conjugate

The lack of efective pharmacological treatments for acute kidney injury (AKI) remains a signifcant public health problem. Given the involvement of apoptosis and regulated necrosis in the initiation and progression of AKI, the inhibition of cell death may contribute to AKI prevention/recovery. Curcuminoids are a family of plant polyphenols that exhibit attractive biological properties that make them potentially suitable for AKI treatment. Now, in cultured tubular cells, we demonstrated that a crosslinked self-assembled star-shaped polyglutamate (PGA) conjugate of bisdemethoxycurcumin (StPGA-CL-BDMC) inhibits apoptosis and necroptosis induced by Tweak/TNFα/IFNγ alone or concomitant to caspase inhibition. St-PGA-CL-BDMC also reduced NF-κB activation and subsequent gene transcription. In vivo, St-PGA-CL-BDMC prevented renal cell loss and preserved renal function in mice with folic acid-induced AKI. Mechanistically, St-PGA-CL-BDMC inhibited AKI-induced apoptosis and expression of ferroptosis markers and also decreased the kidney expression of genes involved in tubular damage and infammation, while preserving the kidney expression of the protective factor, Klotho. Thus, due to renal accumulation and attractive pharmacological properties, the application of PGAbased therapeutics may improve nephroprotective properties of current AKI treatmentsTis work was supported by grants from the Instituto de Salud Carlos III, FEDER funds: PI16/02057, PI16/01900, PI18/01133, PI19/00815, ISCIII RETIC REDINREN RD16/0009; Sociedad Española de Nefrología; FRIAT; Comunidad de Madrid en Biomedicina B2017/BMD-3686 CIFRA2-CM; ERA-PerMed-JTC2018 (AC18/00071; DTS18/00032); Spanish Ministry of Economy and Competitiveness (Grant numbers SAF2013-44848-R, SAF2016-80427-R). Partly co-funded by FEDER (PO FEDER Valencian Community - 2014–2020

Type-Specific Identification of Genital Human Papillomavirus Infection in Women with Cytological Abnormality

Objectives: To estimate the frequency of human papillomavirus (HPV) infection and the genotype distribution of HPV among women with a Pap smear showing atypical squamous cells of undetermined significance (ASC-US) attending the Program for the Detection and Control of Cervical Cancer in Bogotá, Colombia. Study Design: Cervical samples from 200 women with an ASC-US Pap smear were analyzed for the presence of HPV DNA and genotype distribution using a commercial molecular technique (Linear Array®; Roche Molecular Systems, USA). Results: HPV infection was found in 140 women (70%). High-risk HPV types were present in 46.4% of the samples; 16.4% showed a low-risk HPV type, and 37.1% showed both. Of the positive samples, 42.9% were infected with a single viral genotype, whereas 57.1% exhibited multiple HPV infections. The most common HPV genotypes were HPV 16, 53, and 52 with a prevalence of 26.4, 16.4, and 13.6%, respectively. Conclusion: The epidemiological characterization of HPV infections described in this study might guide actions for epidemiological surveillance to strengthen the program in Bogotá and to develop appropriate HPV vaccination programs.Instituto de Genética Veterinari

Hacia la construcción de la plataforma integrada de información para el sector salud de México

Objetivo. Estandarizar técnica, funcional y operativamente los principales sistemas de información en salud de la Subsecretaria de Promoción y Prevención de la Salud de México (SPPS) de la Secretaría de Salud Federal (SSA). Metodología. Se realizó el diagnóstico de los sistemas de información de la SPPS y se priorizaron los hallazgos con base en los requerimientos y necesidades, para llevar a cabo las acciones de estandarización, mantenimiento y actualización. Resultados. Se evaluaron y realizaron mejoras a nueve sistemas de información, mismos que se encuentran operando de manera regular o en fase pre-operativa para el apoyo del monitoreo de programas preventivos.Sociedad Argentina de Informática e Investigación Operativ

Hacia la construcción de la plataforma integrada de información para el sector salud de México

Objetivo. Estandarizar técnica, funcional y operativamente los principales sistemas de información en salud de la Subsecretaria de Promoción y Prevención de la Salud de México (SPPS) de la Secretaría de Salud Federal (SSA). Metodología. Se realizó el diagnóstico de los sistemas de información de la SPPS y se priorizaron los hallazgos con base en los requerimientos y necesidades, para llevar a cabo las acciones de estandarización, mantenimiento y actualización. Resultados. Se evaluaron y realizaron mejoras a nueve sistemas de información, mismos que se encuentran operando de manera regular o en fase pre-operativa para el apoyo del monitoreo de programas preventivos.Sociedad Argentina de Informática e Investigación Operativ