Characterization and computation of ancestors in reaction systems

AbstractIn reaction systems, preimages and nth ancestors are sets of reactants leading to the production of a target set of products in either 1 or n steps, respectively. Many computational problems on preimages and ancestors, such as finding all minimum-cardinality nth ancestors, computing their size or counting them, are intractable. In this paper, we characterize all nth ancestors using a Boolean formula that can be computed in polynomial time. Once simplified, this formula can be exploited to easily solve all preimage and ancestor problems. This allows us to directly relate the difficulty of ancestor problems to the cost of the simplification so that new insights into computational complexity investigations can be achieved. In particular, we focus on two problems: (i) deciding whether a preimage/nth ancestor exists and (ii) finding a preimage/nth ancestor of minimal size. Our approach is constructive, it aims at finding classes of reactions systems for which the ancestor problems can be solved in polynomial time, in exact or approximate way

Pelotaris

La propuesta es reflexionar en torno a la construcción del documental Pelotaris, cómo se desarrolla a través de la indagación y la búsqueda de la cámara en las situaciones que lo rodean. De qué forma el encuadre actúa como pieza fundamental para la construcción de sentido componiendo la ventana cinematográfica que deja ver gestos, miradas, rostros y destrezas deportivas del universo que allí comulga. Y cómo se configura una estructura en el montaje a partir de la selección y manipulación del material; trabajando sobre el tiempo y en las conexiones dadas por la unión de planos, manifestando un recorrido particular, un relato que trasluce una mirada propia.pass para visualizar el video: navarroFacultad de Arte

Análisis de la recepción de un dispositivo digital sobre el estudio en matemática : Un caso de producción curricular para las escuelas primarias de la provincia de Buenos Aires

Tesis para optar por el grado de Especialista en Enseñanza de las Matemáticas para el Nivel Inicial y el Nivel Primario, dirigida por la Dra. Claudia Broitman. En este trabajo se analiza la recepción en territorio de un conjunto de podcast producidos por el Equipo Curricular de Matemática de la Dirección Provincial de Educación Primaria. Dicha serie de audios trata el popular tema del "estudio en matemática" desde una mirada apoyada en los aportes de la Didáctica de la Matemática de la escuela francesa. En mi TFI analizo la llegada que tuvo la serie a maestras, maestros, equipos directivos y formadoras o formadores de docentes en relación al nivel de difusión, así como al grado de acuerdo con las ideas planteadas y su percepción como novedosas. En cierto grado, el hecho que la difusión oficial se haya realizado por al canal virtual de la DGCyE (abc.gob.ar) se muestra como insuficiente para la masividad; cuestión que pretende ser central en las publicaciones oficiales destinadas a la mejora de la enseñanza.Facultad de Humanidades y Ciencias de la Educació

Laser assisted electrodeposition of binary metallic alloys from water-based electrolytes: The case of palladium‐platinum

The present work investigates the applicability of laser assisted electrodeposition (LAE) to the plating of binary metallic alloys from aqueous solutions and in absence of any external polarization. PdPt was chosen as proto-typical system and the deposition was carried out from phosphate-based electrolytes. The effect of electrolyte formulation and laser parameters on the composition, thickness and physical properties of the alloys was studied. In order to provide more insight on the LAE deposition process of alloys, the electrochemical properties of the electrolytes employed were correlated with the properties of the materials obtained. In analogy with standard alloy plating processes, a clear link between the currents observed for the reduction of the two single metals and the composition/thickness of the coated PdPt layers could be established. Compositionally tunable and continuous PdPt coatings were obtained and their chemical, morphological and mechanical properties were determined. Finally, the possibility to selectively deposit the PdPt alloy was demonstrated by patterning a complex figure

Nickel Phosphides Fabricated through a Codeposition–Annealing Technique as Low-Cost Electrocatalytic Layers for Efficient Hydrogen Evolution Reaction

Water splitting will be one of the most strategic techniques in the upcoming hydrogen-based economy. In this context, the development of efficient and low-cost Pt-free electrocatalysts is crucial t..

Subcutaneous tocilizumab in rheumatoid arthritis: findings from the common-framework phase 4 study programme TOZURA conducted in 22 countries

Objectives The aim of this pooled analysis of the TOZURA study programme was to evaluate the efficacy and safety of subcutaneous tocilizumab (TCZ-SC) as monotherapy or in combination with conventional synthetic DMARDs (csDMARDs) in patients with moderate to severe RA who had an inadequate response to csDMARD or anti-TNF agent therapy or who were MTX naïve. Methods TOZURA is a multinational, open-label, single-arm, common-framework, phase 4 study programme (11 protocols, 22 countries). Patients received TCZ-SC 162 mg each week for ⩾24 weeks, administered at the investigator’s discretion, as monotherapy or in combination with a csDMARD. Efficacy, safety and immunogenicity were evaluated; propensity score–based matching was used for between-group comparisons. Results Of 1804 patients, 353 (19.6%) received monotherapy and 1451 (80.4%) received combination therapy. The 28-joint DAS using ESR (DAS28-ESR) in both groups decreased significantly from baseline to week 24 (mean change: monotherapy −3.40, combination therapy −3.46), with no significant difference between groups (P = 0.46). The proportion of patients who achieved DAS28-ESR or Clinical Disease Activity Index remission or ACR 20/50/70/90 responses was similar between groups. Overall, 13.9% of patients withdrew—6.2% for safety reasons and 1.6% for insufficient therapeutic response; 5.8% of patients experienced one or more serious adverse events [14.6/100 patient-years (PY)]; six deaths occurred (0.64/100 PY). Conclusion In a common framework of 11 studies in 22 countries, this phase 4 study programme confirmed TCZ-SC’s known efficacy and safety profile with comparable effects as monotherapy and in combination with csDMARDs

Possible compensation of structural and viscotropic properties in hepatic microsomes and erythrocyte membranes of rats with essential fatty acid deficiency

The effect of essential fatty acid deficiency on the structural and dynamic properties of the lipid matrix of rat liver microsomes and erythrocyte membranes was studied. The rate and range of the rotational mobility of 1,6-diphenyl-1,3,5-hexatriene and 2-, 7-, and 12-(9-anthroyloxy)stearate probes in the native membranes and in lipid vesicles prepared with the total lipid extracts of these membranes were evaluated by using differential polarized phase fluorometry. For the anthroyloxystearate probes, two modes of rotation (in and out of the plane of the aromatic anthracene ring) were partially resolved by measuring at different excitation wavelengths. The fat-free diet produces important changes in the fatty acid composition of the different glycerophospholipid classes without affecting the total double-bond number, the relative contents of cholesterol, phospholipid, and protein, and the glycerophospholipid class distribution. The principal changes, more pronounced in liver microsomes than in erythrocytes, are: an increase in nonessential monoene and triene (18:1n-9 and 20:3n-9) and a decrease in essential diene (18:2n-6) and tetraene (20:4n-6). These changes modify the double-bond distribution as a function of the distance from the interphase toward the bilayer interior, with a significant deficit (15% in erythrocytes and 30% in liver microsomes) in the double-bond density in the intermediate region of the membrane leaflet, corresponding to the carbon number 11-12 of an extended saturated acyl chain, and where the 12-anthroyloxystearate probe is located. In spite of the changes in fatty acid composition and double-bond distribution, with the only exception of a slight increase (about 15%) in the “out of the plane” rotation rate of the 7-(9-anthroyloxy)stearate probe in the erythrocyte lipid vesicles, no other significant change is observed. Thus, the changes in fatty acid composition would take place in such a way that at least the average structural and viscotropic properties of the lipid phase of the membrane, sensed by these probes, would be almost exactly compensated.Instituto de Investigaciones Bioquímicas de La Plat

Electrochemical treatment coupled with solar light-driven photocatalytic approach: A challenging process in cascade for hydrogen production and wastewater remediation

This study presents an innovative approach for simultaneous hydrogen production and wastewater remediation, integrating electrochemical treatment with solar light-driven photocatalysis. The research focuses on the use of a noble metal-free cathode, based on a electrodeposited composite of Co2P and elemental P, for efficient hydrogen generation from simulated wastewater through water splitting. This composite is characterized, in its optimized form, by an overpotential equal to 133.6 mV (at 10 mA cm-2) and by a Tafel slope of 60.5 mV dec-1. Challenges like the high potential required for the Oxygen Evolution Reaction (OER) and the use of expensive noble metals in electrodes are addressed by employing earth-abundant compounds for electrode fabrication. Additionally, the study explores the degradation of diclofenac (DCF) in wastewater, demonstrating that electrochemical treatment alone is insufficient for organic matter removal. Therefore, a coupled process involving a first electrochemical treatment step followed by a photocatalytic process using BiOCl is proposed. Thanks to the exposure of the (110) active face, BiOCl possesses excellent photocatalytic performances even under solar light irradiation. This hybrid approach not only enhances the efficiency of DCF degradation (about 90%) and reaches an organic matter removal of 59%, but it also improves hydrogen production, offering a sustainable solution for energy generation and water purification in the face of increasing global industrialization and water scarcity

Electrodeposition of zinc-nickel alloys from ethylene glycol-based electrolytes in presence of additives for corrosion protection

In the present work the electrodeposition of zinc-nickel alloys with 15-20 wt.% nickel from non-aqueous solutions based on ethylene glycol is investigated. Potentiostatic deposition conditions are used, which are found to offer optimal coating quality and superior control over composition. In addition, ammonium chloride is evaluated as additive to partially suppress zinc incorporation into the deposit and to enhance layer quality. Layers composition, surface morphology of the deposits and their anticorrosive properties are investigated. The electrochemical characteristics of the Zn-Ni electrolytes are studied using cyclic voltammetry measurements. From the phase composition point view, X-ray diffraction results confirm that a metastable γ phase is present in the as deposited Zn-Ni alloys with nickel content 16-18 wt.%. Corrosion tests show that the barrier behaviour against corrosion of Zn-Ni films electrodeposited from the NH4Cl containing bath is superior in comparison to layers plated from an additive-free bath. The use of the additive enlarges the grains and provides a compact surface structure, which upskills the anticorrosive behaviour of the deposit

ARCA. Semantic exploration of a bookstore

In this demo paper, we present ARCA, a visual-search based system that allows the semantic exploration of a bookstore. Navigating a domain-specific knowledge graph, students and researchers alike can start from any specific concept and reach any other related concept, discovering associated books and information. To achieve this paradigm of interaction we built a prototype system, flexible and adaptable to multiple contexts of use, that extracts semantic information from the contents of a books' corpus, building a dedicated knowledge graph that is linked to external knowledge bases. The web-based user interface of ARCA integrates text-based search, visual knowledge graph navigation, and linear visualization of filtered books (ordered according to multiple criteria) in a comprehensive coordinated view aimed at exploiting the underlying data while avoiding information overload and unnecessary cluttering. A proof-of-concept of ARCA is available online at http://arca.diag.uniroma1.i