On Logical Depth and the Running Time of Shortest Programs

The logical depth with significance $b$ of a finite binary string $x$ is the shortest running time of a binary program for $x$ that can be compressed by at most $b$ bits. There is another definition of logical depth. We give two theorems about the quantitative relation between these versions: the first theorem concerns a variation of a known fact with a new proof, the second theorem and its proof are new. We select the above version of logical depth and show the following. There is an infinite sequence of strings of increasing length such that for each $j$ there is a $b$ such that the logical depth of the $j$th string as a function of $j$ is incomputable (it rises faster than any computable function) but with $b$ replaced by $b+1$ the resuling function is computable. Hence the maximal gap between the logical depths resulting from incrementing appropriate $b$'s by 1 rises faster than any computable function. All functions mentioned are upper bounded by the Busy Beaver function. Since for every string its logical depth is nonincreasing in $b$, the minimal computation time of the shortest programs for the sequence of strings as a function of $j$ rises faster than any computable function but not so fast as the Busy Beaver function.Comment: 12 pages LaTex (this supercedes arXiv:1301.4451

Mineral composition of pollen using inductively coupled plasma atomic emission spectroscopy

Pollen collected by honey bees (bee pollen) is promoted as a health food supplement with a wide range of nutritional and health beneficial properties. While honey is an important source of proteins for the bee colony, pollen is the bees' main source for other important nutrients, such as minerals, fats, fibers, carbohydrates, and other substances. The composition of pollen is rather variable and depends on the botanical origin of the pollen. In this work we studied the mineral content of bee pollen of three botanical origins (Cistus ladanifer L., Rubus ulmifolius Schott, and Calluna vulgaris (L.) Hull) and two geographic sites in the central Portugal (Caniçal and Vale Grande). Inductively coupled plasma atomic emission spectrometry (ICP-AES) was used for the determination of cadmium, chromium, copper, iron, lead, manganese, and zinc. Prior to ICP-AES measurement, the samples were mineralized by treatment with HNO3 and H2O2 at 100 °C until complete digestion. The analyzed elements presented levels corresponding to the usual reference range [1]. The concentrations of micronutrients (Cu, Fe, Mn and Zn) presented characteristic profiles which differed between the three plant species, but where similar in the two geographic areas. The main minerals observed for R. ulmifolius and C. vulgaris were Fe and Mn, and Zn for C. ladanifer. Heavy metals (Cd, Cr and Pb) were present at low concentrations (Table 1), indicating that there were no sources of contamination. In conclusion, the determination of micronutrients in pollen could be suitable for the identification of botanical species. The investigation of element profile, in combination with modern statistical data evaluation techniques, can be a promising approach to identify the botanical source of pollen.info:eu-repo/semantics/publishedVersio

Thermoelectric response of Fe1+y_{1+y}Te0.6_{0.6}Se0.4_{0.4}: evidence for strong correlation and low carrier density

We present a study of the Seebeck and Nernst coefficients of Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ extended up to 28 T. The large magnitude of the Seebeck coefficient in the optimally doped sample tracks a remarkably low normalized Fermi temperature, which, like other correlated superconductors, is only one order of magnitude larger than T$_c$. We combine our data with other experimentally measured coefficients of the system to extract a set of self-consistent parameters, which identify Fe$_{1+y}$Te$_{0.6}$Se$_{0.4}$ as a low-density correlated superconductor barely in the clean limit. The system is subject to strong superconducting fluctuations with a sizeable vortex Nernst signal in a wide temperature window.Comment: 4 pages including 4 figure

Aerosol and precipitation chemistry in a remote site in Central Amazonia: the role of biogenic contribution

International audienceA long-term (2?3 years) measurement of aerosol and precipitation chemistry was carried out in a remote site in Central Amazonia, Balbina, (1°55' S, 59°29' W, 174 m above sea level), about 200 km north of Manaus city. Aerosols were sampled using stacked filter units (SFU), which separate fine (d<2.5 ?m) and coarse mode (2.5 ?

Técnicas alternativas no controle de podridões pós-colheita de pêssegos.

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Honey sugars analysis by ion chromatography method with Integrated Pulsed Amperometric Detection (IPAD)

Glucose and fructose are the most important monosaccharides in honey, these sugars combined in various forms comprise the di- and trisaccharide fractions of floral honey. Frutose/glucose ratio can influence the flavor of honey since fructose is sweeter than glucose. Honeys with higher fructose/glucose ratios remain liquid for longer periods. Several Chromatographic methods have been used to evaluate the sugar content of honey, although the Integrated Pulsed Amperometric Detection (IPAD) only recently became to be used. In order to characterize the sugar content in honey from different botanical origins a Dionex ICS3000 ion chromatograph was used. Separation was performed in a column “CarboPacTM PA20 3x150mm”, with a precolumn “CarboPacTM PA20 3x30mm”. Electrochemical detector in Integrated Pulsed Amperometric Detection (IPAD) mode was used. The elution was performed with a gradient with two NaOH solutions (10 and 200 mM). Standard solutions of glucose, fructose and sucrose, were used to identify and quantify the individual sugar components in the honey samples. The method showed a good separation between the compounds (resolution> 3.3 and more than 9000 theoretical plates). The response was linear in the range (0.05 to 1.00 mg/L for fructose and glucose and 0.01 to 0.20 mg/L for sucrose). The detection limits were 0.014 mg/L for glucose, 0.007 mg/L for fructose and 0.003 mg/L for sucrose. Twenty six monofloral honey samples from Erica, Citrus, Lavandula and Eucalyptus were tested. 5,000 g of each honey sample was diluted to 1 mg/L and filtered with a 0.45 m polypropylene filter prior to HPLC analysis. The results show that the fructose/glucose ratios are in accordance with the different honeys analyzed and the HPLC-IPAD is a good methodology to determine the sugar content in honey, with low solvent consumption and residues

Utilização do teor em metais pesados no pólen como marcador ambiental : estudo preliminar

Este trabalho apresenta os resultados preliminares sobre a avaliação de metais pesados no pólen de plantas que vegetam em locais com diferentes níveis de poluição. Foram recolhidas amostras de pólen diretamente das plantas em zonas onde havia suspeita de contaminações diversas, nomeadamente junto a estradas, em solos com alguma contaminação e num pomar. Foi também recolhido pólen apícola em zonas consideradas mais poluídas. Analisaram-se um total de 10 amostras e para cada uma delas foram determinadas as concentrações em Cádmio(Cd), Crómio(Cr), Ferro(Fe), Zinco(Zn), Manganês(Mn), Cobre(Cu) e Chumbo(Pb). As amostras de pólen foram secas a 50ºC/24 horas e ulteriormente mineralizadas com uma mistura de HNO3 e H2O2. As concentrações dos metais referidos foram determinadas por espectrometria de emissão de plasma (ICP-OES). Nas amostras recolhidas junto a uma estrada, num pomar e num terreno perto de uma antiga lixeira verificaram-se níveis elevados de Fe, Mn e Pb enquanto que para os restantes metais analisados os níveis estavam dentro dos valores de referência para o pólen. Estes resultados preliminares fazem parte de um estudo mais completo onde se pretende correlacionar os níveis de metais pesados no pólen com os contaminantes presentes nos solos, e para já foi possível verificar que pode ser assim contaminado por eles dependendo do meio onde vegetam as plantas, confirmando a hipótese de pode ser usado como marcador ambiental

Surgery for pulmonary aspergiloma: curative?

Introduction.In lhe last few decades, there has been an increase in fungal diseases, especially in those caused by Aspergillus.The aim of this retrospective study was to confirm or ascertain whether surgical intervention to pulmonary aspergiloma can result in a cure or long term palliative treatment with improvement of quality of life. Methods and materiais. From 1989 to 2001, 23 patients with mean age of 44.1 years (18-69 years) were submitted to pulmonary surgery for excision of aspergilloma. Sixteen patients were mate (70%). The most frequent indication for surgery was haemoptysis in 16 patients (70%) followed by abundant sputum in 3 patients (3%). Four patients (17%) were asymptomatic. Old tuberculosis lesions (87%) or pulmonary abscesses (13%) were lhe basic conditions for lhe aspergilloma. Pre-operative evaluation of respiratory function showed a mean vital capacity of 69.8% (61-84% limits) and lhe mean Fevl was 66% (53-82% limits). Results. This group of patients were submitted to 18 lobectomies (82%), 2 bilobectomies (7%), 2 wedge resections and 1 pneumonectomy (4%). There was no operative mortality and lhe morbidity in lhe post-operative period was: persistent air leak in 7 patients (30%), post-operative bleeding in 2 patients (7%) and residual cavities in 2 patients (7%). The mean time of follow-up was 7.2 years (limits 1.5-14 years) and 3 deaths were registered. Two deaths were related to intestinal neoplasia and 1 related to lhe original disease, 5 years after surgery. All surviving patients referred good improvement of symptoms and quality of life. Conclusions. The resection of pulmonary aspergilloma could be performed with a low morbidity and mortality. The patients referred good improvement of symptoms and quality of life after surgery. Consequently, we suggest that surgical therapy is an option for both symptomatic and asymptomatic patient

Mechanical and tribological characterization of four commercial braking formulation materials

Organic friction materials for brake linings, namely brake pads are polymer matrix composites usually containing numerous macroscopic as well as microscopic constituents such as filamentary reinforcements, solid lubricants, abrasives and fillers. Their main objective of the these composite system are that a constant and stable coefficient of friction (COF) is provided irrespective of environmental conditions such as pressure, sliding velocity, temperature, humidity etc. Brake pads performance should be maintained over a wide range of stress conditions. Although the wear of the brake pad is inevitable, it should be minimized as far as possible. While cast iron has been the dominant material for brake discs, brake pad materials are constantly evolving into more complex composites. The main objectives of the present work is to characterize the physical and the tribological behavior of four commercial braking pads material formulations. For all compositions the studied factors are normal pressure and sliding speed, considering one braking-test protocol designed with temperature and friction load data acquisition. A double pad-on-disc tribological test configuration was used to determine tribological properties of brake pad for heavy vehicles commercial. Three wear tests via increased severity of rubbing conditions for a constant braking distance.The authors acknowledge Auto Travões Viseu-recondicionamento de Travões e embraiagens Lda the support through the provision of the frictrion linning materials presented in the study