A Note on the Shannon Entropy of Short Sequences

For source sequences of length L symbols we proposed to use a more realistic value to the usual benchmark of number of code letters by source letters. Our idea is based on a quantifier of information fluctuation of a source, F(U), which corresponds to the second central moment of the random variable that measures the information content of a source symbol. An alternative interpretation of typical sequences is additionally provided through this approach.Comment: 3 figure

Resource competition and ageism: a study of the influence of employment scarcity on the endorsement of ageist attitudes

2015 Spring.Includes bibliographical references.The major economic recession of 2007, which has disproportionately affected younger workers, and the rapid growth of the older population have created an environment where younger persons are economically disenfranchised and a highly visible older population persists in the labor force at a time when jobs are scarce. Intergenerational conflict may arise under these conditions due to perceived competition over economic resources, consistent with Realistic Group Conflict Theory, which posits that negative intergroup perceptions arise when the success of one group is threatened by another, potentially leading to intergroup hostility. Younger workers may perceive older workers as a threat to their economic well-being and thus harbor ageist perceptions about them. To test this hypothesis, survey data was collected from 395 participants using Amazon's Mechanical Turk. The survey collected information about current employment status, duration of longest unemployment, number of peers unemployed, underemployment, job insecurity, and endorsement of ageist beliefs. Work centrality was investigated as a potential moderator for these relationships and perception of threat felt from older persons as a potential mediator. Results indicated that underemployment and job insecurity were both significant predictors of ageism. Workers who experienced greater underemployment or job insecurity were more likely to harbor ageist beliefs. Additionally, work centrality moderated relationships between peer unemployment and ageism, and perception of threat from older persons mediated relationships between underemployment/job insecurity and ageism. This study provides insight into how perceptions of age are influenced by economic factors and how a vulnerable group in society is affected during periods of economic turmoil

Obtaining Au thin films in atmosphere of reactive nitrogen through magnetron sputtering

4d and 5d series of the transition metals are used to the obtaining nitrides metallic, due to the synthesis of PtN, AgN and AuN in the last years. Different nitrides are obtained in the Plasma Assisted Physics Vapour Deposition system, due to its ionization energy which is necessary for their formation. In this paper a Magnetron Sputtering system was used to obtain Au thin films on Si wafers in Nitrogen atmosphere. The substrate temperature was varied between 500 to 950°C. The samples obtained at high temperatures (>500°C) show Au, Si and N elements, as it is corroborated in the narrow spectrum obtained for X-Ray Photoelectron Spectroscopy; besides the competition of orientation crystallographic texture between (111) and (311) directions was present in the X-Ray Diffraction analysis to the sample heated at 950°C

Eigenvalue estimates for submanifolds of warped product spaces

We give lower bounds for the fundamental tone of open sets in minimal submanifolds immersed into warped product spaces of type $N^n \times_f Q^q$, where $f \in C^\infty(N)$. We also study the essential spectrum of these minimal submanifolds.Comment: 17 page

Patient centred diagnosis: sharing diagnostic decisions with patients in clinical practice.

Patient centred diagnosis is best practised through shared decision making; an iterative dialogue between doctor and patient, whichrespects a patient’s needs, values, preferences, and circumstances. Shared decision making for diagnostic situations differs fundamentally from that for treatment decisions. This has important implications when considering its practical application. The nature of dialogue should be tailored to the specific diagnostic decision; scenarios with higher stakes or uncertainty usually require more detailed conversation

Neotropical stingless bees display a strong response in cold tolerance with changes in elevation

Tropical pollinators are expected to experience substantial effects due to climate change, but aspects of their thermal biology remain largely unknown. We investigated the thermal tolerance of stingless honey-making bees, the most ecologically, economically and culturally important group of tropical pollinators. We assessed changes in the lower (CTMin) and upper (CTMax) critical thermal limits of 17 species (12 genera) at two elevations (200 and 1500 m) in the Colombian Andes. In addition, we examined the influence of body size (intertegular distance, ITD), hairiness (thoracic hair length) and coloration (lightness value) on bees’ thermal tolerance. Because stingless beekeepers often relocate their colonies across the altitudinal gradient, as an initial attempt to explore potential social responses to climatic variability, we also tracked for several weeks brood temperature and humidity in nests of three species at both elevations. We found that CTMin decreased with elevation while CTMax was similar between elevations. CTMin and CTMax increased (low cold tolerance and high heat tolerance) with increasing ITD, hair length and lightness value, but these relationships were weak and explained at most 10% of the variance. Neither CTMin nor CTMax displayed significant phylogenetic signal. Brood nest temperature tracked ambient diel variations more closely in the low-elevation site, but it was constant and higher at the high-elevation site. In contrast, brood nest humidity was uniform throughout the day regardless of elevation. The stronger response in CTMin, and a similar CTMax between elevations, follows a pattern of variation documented across a wide range of taxa that is commonly known as the Brett’s heat-invariant hypothesis. Our results indicate differential thermal sensitivities and potential thermal adaptations to local climate, which support ongoing conservation policies to restrict the long-distance relocations of colonies. They also shed light on how malleable nest thermoregulation can be across elevations

Nesting habitats and rates of cell parasitism in some bee species of the genera ancyloscelis, centris and euglossa (Hymenoptera: Apidae) from Colombia

We describe a dense nest aggregation of Ancyloscelis aff. apiformis, two nests of Centris flavifrons, and six nests of Euglossa. We found a nest of E. analis built inside a cavity of a living tree, an aerial nest of E. cybelia attached under a leaf of a palm tree and four nests of E. nigropilosa associated with timber buildings and abandoned nests of carpenter bees (Xylocopa sp.). We report for the first time wasps of the family Eurytomidae (Hymenoptera: Chalcidoidea) and a cuckoo bee, Coelioxys (Rhinocoelioxys) sp. (Hymenoptera: Megachilidae), attacking the brood cells of E. cybelia and E. nigropilosa. We also briefly discuss the variation found in the nest structure of C. flavifrons; unlike those nests studied in Costa Rica and northeastern Brazil, the nests in Colombia were shallow (~12 cm) and consisted of a main tunnel with three short branches, each one ending in a single cell. Further data from other localities are needed to detect other variations in the nesting biology and if they are correlated with the morphological variation exhibited by this species or with local differences in parasite pressure

Nuevos registros de abejas megachilidas (Hymenoptera: Megachilidae) para Colombia

The bee family Megachilidae consists of solitary species, some of which are important pollinators of cultivated plants. Although literature records indicate the existence of about 50 species of 10 genera of megachilid bees in Colombia, taxonomic studies are lacking and thus limited information is available on their identity as well as their distribution in the country. Herein, we provide new geographical records for the following ten species: Anthidium sanguinicaudum Schwarz, Chelostomoides otomita (Cresson), Hoplostelis bilineolata (Spinola), Megachile amparo Gonzalez, M. kalina Gonzalez et al., M. lorenziensis Mitchell, M. moderata Smith, M. simillima Smith, Pseudomegachile lanata (Fabricius), and Stelis costaricensis Friese. We report M. kalina for the first time for the country.Las abejas de la familia Megachilidae son especies solitarias, algunas de ellas importantes polinizadores de cultivos. Aunque en la literatura se registran cerca de 50 especies de 10 géneros de abejas megachilidas en Colombia, faltan estudios taxonómicos y, por lo tanto, se dispone de información limitada sobre la identidad y la distribución de este grupo en el país. En este trabajo proporcionamos nuevos registros geográficos para 10 especies poco conocidas [Anthidium sanguinicaudum Schwarz, Chelostomoides otomita (Cresson), Hoplostelis bilineolata (Spinola), Megachile amparo Gonzalez, M. kalina Gonzalez et al., M. lorenziensis Mitchell, M. moderata Smith, M. simillima Smith, Pseudomegachile lanata (Fabricius), y Stelis costaricensis Friese]. Megachile kalina se registra por primera vez para Colombia

The genus Galeandra (Orchidaceae) in Argentina

Galeandra (Orchidaceae) comprende alrededor de 18 especies de hierbas epífitas y terrestres de distribución neotropical, las cuales son reconocidas por presentar las flores con el labelo en forma de embudo y espolonado en la base. Cuatro especies de Galeandra fueran citadas para la flora Argentina en previos trabajos taxonómicos: G. beyrichii, G. graminoides, G. hysterantha y G. styllomisantha. El objetivo de esta contribución fue realizar el estudio taxonómico de Galeandra en Argentina. Se reconocen a G. beyrichii y G. xerophila para el territorio argentino, esta última se cita por primera vez. Galeandra graminoides y G. stylomisantha, se consideran como citas dudosas para la flora Argentina. El tratamiento incluye una clave de identificación, descripciones, fotografías de campo, observaciones, distribución y hábitat para cada especie.Galeandra (Orchidaceae) comprises about 18 species of epiphytic and terrestrial neotropical herbs. The genus is recognized by its flowers with funnel-shaped lip and spurred at the base. Four species of Galeandra have been recognized for the Argentinean flora in previous taxonomics studies: G. beyrichii, G. graminoides, G. hysterantha and G. styllomysantha. The aim of this contribution was to do a taxonomic treatment of Galeandra for Argentina. We recognize to G. beyrichii and G. xerophila, the last one is a new record for the argentinean flora. Galeandra graminoides and G. stylomisantha, are considered a doubtful report. The treatment includes an identification key, descriptions, geographic distributions data and habitat, field photographs, observations and comments on each species.Fil: Zanotti, Christian Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Ospina Gonzalez, Juan Camilo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Monteiro, Silvana H. N.. Instituto de Pesquisas Jardim Botânico do Rio de Janeiro; Brasi

Discovery of Megachile (Pseudomegachile) lanata (Fabricius, 1775) (Hymenoptera, Megachilidae) in Colombia, an adventive bee species from the Old World

This work is licensed under a Creative Commons Attribution 4.0 International License.We record for the first time for Colombia Megachile (Pseudomegachile) lanata (Fabricius, 1775), a bee species from Southeast Asia. This is the first record of an adventive bee species for the country besides Apis mellifera Linnaeus, 1758, the European honey bee. Megachile lanata appears to have arrived to the Caribbean coast of Colombia nearly half a century ago, reaching the Orinoquia region recently. We provide comments on diagnostic features to facilitate the recognition of this bee species and discuss its possible establishment in Colombia