134 research outputs found
Evaluating space measures in P systems
P systems with active membranes are a variant of P systems where membranes can be created by division of existing membranes, thus creating an exponential amount of resources in a polynomial number of steps. Time and space complexity classes for active membrane systems have been introduced, to characterize classes of problems that can be solved by different membrane systems making use of different resources. In particular, space complexity classes introduced initially considered a hypothetical real implementation by means of biochemical materials, assuming that every single object or membrane requires some constant physical space (corresponding to unary notation). A different approach considered implementation of P systems in silico, allowing to store the multiplicity of each object in each membrane using binary numbers. In both cases, the elements contributing to the definition of the space required by a system (namely, the total number of membranes, the total number of objects, the types of different membranes, and the types of different objects) was considered as a whole. In this paper, we consider a different definition for space complexity classes in the framework of P systems, where each of the previous elements is considered independently. We review the principal results related to the solution of different computationally hard problems presented in the literature, highlighting the requirement of every single resource in each solution. A discussion concerning possible alternative solutions requiring different resources is presented
Innovative development of the Octopus (cf) tetricus fishery in Western Australia
In 2010 the broad-scale introduction of a new gear type, the trigger trap, saw a 260% (33 t in 2009 to 119 t in 2010) increase in octopus landings in the Western Australian Developmental Octopus Fishery (DOF). Deployed in waters previously unfished by the DOF, initial catches demonstrated that trigger traps were more efficient and captured a different component of the population, compared to open-ended shelter pots traditionally used in the fishery. This shift caused a surge of interest in commercial octopus fishing
Evaluación del negocio de la engorda bovina en predios adscritos al programa de planteles animales bajo certificación oficial en la zona de Chillán
El sector pecuario nacional ha experimentado cambios importantes durante los últimos años que lo han llevado a convertirse en una alternativa más, dentro de las opciones de exportación. En este contexto la implementación del programa de Planteles Animales Bajo Certificación Oficial (PABCO) ha planteado a todos los integrantes de la cadena de producción y comercialización desafíos en cuanto al cumplimiento de estándares de calidad exigidos por los distintos mercados de destino, como lo es la utilización de sustancias con efecto anabolizante y la alimentación del animal, prácticas que pueden ir de la mano y que tiene un peso importante en los costos productivos y por ende en el resultado exitoso del negocio Este estudio evalúa el negocio de la engorda bovina de productores pertenecientes al programa PABCO, mediante la conformación de una estructura de costos, con un especial enfoque en los costos de alimentación. La información se obtuvo mediante encuestas y entrevistas a productores de la zona de Chillán y por medio de entrevistas a profesionales de la zona. El análisis se basa en variables cualitativas y cuantitativas de los sistemas productivos, para evaluar los aspectos productivos, económicos y de negocio en la etapa de engorda. Los resultados revelan que al considerar todos los costos de la etapa de engorda, el costo promedio de un animal terminado es de 312.822 para los predios PABCO B. Existe una diferencia de 18.133 y $31.613 por animal para los productores PABCO A y PABCO B, respectivamente, lo que indica que los productores PABCO A, de este estudio, desarrollan una engorda ineficiente desde la perspectiva del negocio.
Climate change adaptation cycle for pilot projects development in small municipalities: The northwestern Italian regions case study
More than half of the European population live in small and medium size municipalities, where climate adaptation planning is an under-researched topic within the climate change field. Many constraints might hinder the implementation of adaptation pilot projects due to lack of economic, knowledge, and technical available resources. Local institutions find difficulties in building a coherent local adaptation planning and design processes with international and national frameworks. In this context, this article proposes a methodology based on the available international frameworks to support the small communities with the aim to implement adaptation pilot projects within different sectors. In doing so, this paper tests a climate change adaptation cycle for pilot projects development in small municipalities; the first in Italy for small municipalities under 20.000 inhabitants. The proposed methodology could lead local adaptation initiatives in climate change risk assessment by supporting the research communities in developing a coherent vision for the local territories and to identify proper oriented measures to enhance demonstrative pilot projects and to increase the level of resilience in small municipalities, avoiding maladaptation
Fredkin Gates for Finite-valued Reversible and Conservative Logics
The basic principles and results of Conservative Logic introduced by Fredkin
and Toffoli on the basis of a seminal paper of Landauer are extended to
d-valued logics, with a special attention to three-valued logics. Different
approaches to d-valued logics are examined in order to determine some possible
universal sets of logic primitives. In particular, we consider the typical
connectives of Lukasiewicz and Godel logics, as well as Chang's MV-algebras. As
a result, some possible three-valued and d-valued universal gates are described
which realize a functionally complete set of fundamental connectives.Comment: 57 pages, 10 figures, 16 tables, 2 diagram
Raman spectroscopy reveals that biochemical composition of breast microcalcifications correlates with histopathologic features
Breast microcalcifications are a common mammographic finding. Microcalcifications are considered suspicious signs of breast cancer and a breast biopsy is required, however, cancer is diagnosed in only a few patients. Reducing unnecessary biopsies and rapid characterization of breast microcalcifications are unmet clinical needs. In this study, 473 microcalcifications detected on breast biopsy specimens from 56 patients were characterized entirely by Raman mapping and confirmed by X-ray scattering. Microcalcifications from malignant samples were generally more homogeneous, more crystalline, and characterized by a less substituted crystal lattice compared with benign samples. There were significant differences in Raman features corresponding to the phosphate and carbonate bands between the benign and malignant groups. In addition to the heterogeneous composition, the presence of whitlockite specifically emerged as marker of benignity in benign microcalcifications. The whole Raman signature of each microcalcification was then used to build a classification model that distinguishes microcalcifications according to their overall biochemical composition. After validation, microcalcifications found in benign and malignant samples were correctly recognized with 93.5% sensitivity and 80.6% specificity. Finally, microcalcifications identified in malignant biopsies, but located outside the lesion, reported malignant features in 65% of in situ and 98% of invasive cancer cases, respectively, suggesting that the local microenvironment influences microcalcification features. This study confirms that the composition and structural features of microcalcifications correlate with breast pathology and indicates new diagnostic potentialities based on microcalcifications assessment. Significance: Raman spectroscopy could be a quick and accurate diagnostic tool to precisely characterize and distinguish benign from malignant breast microcalcifications detected on mammography
Tyrosinase expression in the peripheral blood of stage III melanoma patients is associated with a poor prognosis: a clinical follow-up study of 110 patients
The aim of this study is to define the relationship between the tyrosinase expression in the peripheral blood and the clinical course of the disease in stage III disease-free melanoma patients after radical lymph node dissection. RT-PCR techniques were used to identify tyrosinase mRNA in 110 patients; a total of 542 blood samples were investigated. In all, 54 patients (49%) showed at least one positive result; 13 patients (11.8%) showed baseline positive results: six became negative thereafter, whereas seven showed follow-up positive results until disease progression occurred. One or more positive determinations were found during follow-up in 41 patients with negative baseline tyrosinase. No correlation was found between baseline results and the relapse rate or disease-free survival (DFS), whereas a significant correlation was found between positive tyrosinase results and disease recurrence during follow-up. In fact, 72.9% of positive patients relapsed, but only 19.3% of negative cases did so. The median interval between the positive results and the clinical demonstration of the relapse was 1.9 months (range 1-6.6). Disease-free survival multivariate analysis selected, as independent variables, Breslow thickness (P=0.05), lymph node involvement according to the AJCC classification (P=0.05) and tyrosinase expression (P=0.0001). In conclusion, RT-PCR tyrosinase mRNA expression is a reliable and reproducible marker associated with a high risk of melanoma progression and we encourage its clinical use in routine follow-up
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