324 research outputs found
Structure and distribution of the slope fish community in the vicinity of the sub-Antarctic Prince Edward Archipelago
Demersal fish community structure, distribution and trophic relationships on the slope (depth range 200β1500 m) of the sub-Antarctic Prince Edward Islands and surrounding sea rises were investigated during a pilot survey conducted in April 2001 onboard fishing vessel MV Iris. A total of 56 fish taxa were collected during the survey, of which 44 were identified to the species level, seven to the genus level and five to the family level. Among the identified taxa, 36 constituted new records for the area investigated. Total catch per unit effort (cpue) during the survey ranged from 1β’1 to 241β’2 individuals h 1. Both average fish diversity and total cpue positively correlated with trawling depth. Overall, mean sampling depth and near-bottom temperature explained 56% of total fish cpue. Hierarchal cluster analysis identified three distinct fish assemblages with pronounced dominant species. Major shifts in fish community composition occurred at 500β600 m and 800β900 m depth strata and could probably be a result of physical and biological vertical zonation. Analysis of the diet of selected fish species showed that they were generalist feeders, consuming predominantly pelagic, including epipelagic, meso- and benthopelagic, prey. Diets of six species and nitrogen stable isotope signatures of 22 species revealed that with a few exceptions most fishes occupied the fourth trophic level and were tertiary consumers. Wide variability in carbon isotopic signatures is discussed with respect to alternative, e.g. possible importance of high Antarctic and chemoautotrophic v. photoautotrophic sub-Antarctic primary production, organic matter sources at the base of deep-sea food webs
Repolarization of ferroelectric superlattices BaZrO3/BaTiO3
The study was supported by Russian Science Foundation, project No. β 17-72-20105
Quantum Size Effect transition in percolating nanocomposite films
We report on unique electronic properties in Fe-SiO2 nanocomposite thin films
in the vicinity of the percolation threshold. The electronic transport is
dominated by quantum corrections to the metallic conduction of the Infinite
Cluster (IC). At low temperature, mesoscopic effects revealed on the
conductivity, Hall effect experiments and low frequency electrical noise
(random telegraph noise and 1/f noise) strongly support the existence of a
temperature-induced Quantum Size Effect (QSE) transition in the metallic
conduction path. Below a critical temperature related to the geometrical
constriction sizes of the IC, the electronic conductivity is mainly governed by
active tunnel conductance across barriers in the metallic network. The high 1/f
noise level and the random telegraph noise are consistently explained by random
potential modulation of the barriers transmittance due to local Coulomb
charges. Our results provide evidence that a lowering of the temperature is
somehow equivalent to a decrease of the metal fraction in the vicinity of the
percolation limit.Comment: 21 pages, 8 figure
Longitudinal and transversal piezoresistive response of granular metals
In this paper, we study the piezoresistive response and its anisotropy for a
bond percolation model of granular metals. Both effective medium results and
numerical Monte Carlo calculations of finite simple cubic networks show that
the piezoresistive anisotropy is a strongly dependent function of bond
probability p and of bond conductance distribution width \Delta g. We find that
piezoresistive anisotropy is strongly suppressed as p is reduced and/or \Delta
g is enhanced and that it vanishes at the percolation thresold p=p_c. We argue
that a measurement of the piezoresistive anisotropy could be a sensitive tool
to estimate critical metallic concentrations in real granular metals.Comment: 14 pages, 7 eps figure
Acquired hypopituitarism in a child with secondary hypocorticism after removal of intra-extraventricular (stem) craniophargeoma
This article presents a case of manifestation of acquired hypopituitarism (STH deficiency, secondary hypocorticism, secondary hypothyroidism, diabetes insipidus), accompanied by morbid obesity and its complications: insulin resistance, impaired glucose tolerance, dyslipidemia, secondary arterial hypertension, non-hypertension, non-hypertension, and bilateral epiphysiolysis of the hip joints occurred after removal of the intra-extraventricular craniopharyngeoma in a child after removal after removal of the intraekstraventrikulyarnoy (after beating) kraniofaringeomyΠ Π΄Π°Π½Π½ΠΎΠΉ ΡΡΠ°ΡΡΠ΅ΠΉ ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½ ΡΠ»ΡΡΠ°ΠΉ ΠΌΠ°Π½ΠΈΡΠ΅ΡΡΠ°ΡΠΈΠΈ ΠΏΡΠΈΠΎΠ±ΡΠ΅ΡΠ΅Π½Π½ΠΎΠ³ΠΎ Π³ΠΈΠΏΠΎΠΏΠΈΡΡΠΈΡΠ°ΡΠΈΠ·ΠΌΠ° (Π‘Π’Π-Π΄Π΅ΡΠΈΡΠΈΡ, Π²ΡΠΎΡΠΈΡΠ½ΡΠΉ Π³ΠΈΠΏΠΎΠΊΠΎΡΡΠΈΡΠΈΠ·ΠΌ, Π²ΡΠΎΡΠΈΡΠ½ΡΠΉ Π³ΠΈΠΏΠΎΡΠΈΡΠ΅ΠΎΠ·, Π½Π΅ΡΠ°Ρ
Π°ΡΠ½ΡΠΉ Π΄ΠΈΠ°Π±Π΅Ρ), ΡΠΎΠΏΡΠΎΠ²ΠΎΠΆΠ΄Π°ΡΡΠ΅Π³ΠΎΡΡ ΠΌΠΎΡΠ±ΠΈΠ΄Π½ΡΠΌ ΠΎΠΆΠΈΡΠ΅Π½ΠΈΠ΅ΠΌ ΠΈ Π΅Π³ΠΎ ΠΎΡΠ»ΠΎΠΆΠ½Π΅Π½ΠΈΡΠΌΠΈ: ΠΈΠ½ΡΡΠ»ΠΈΠ½ΠΎΡΠ΅Π·ΠΈΡΡΠ΅Π½ΡΠ½ΠΎΡΡΡΡ, Π½Π°ΡΡΡΠ΅Π½ΠΈΠ΅ΠΌ ΡΠΎΠ»Π΅ΡΠ°Π½ΡΠ½ΠΎΡΡΠΈ ΠΊ Π³Π»ΡΠΊΠΎΠ·Π΅, Π΄ΠΈΡΠ»ΠΈΠΏΠΈΠ΄Π΅ΠΌΠΈΠ΅ΠΉ, Π²ΡΠΎΡΠΈΡΠ½ΠΎΠΉ Π°ΡΡΠ΅ΡΠΈΠ°Π»ΡΠ½ΠΎΠΉ Π³ΠΈΠΏΠ΅ΡΡΠ΅Π½Π·ΠΈΠ΅ΠΉ, Π½Π΅Π°Π»ΠΊΠΎΠ³ΠΎΠ»ΡΠ½ΠΎΠΉ ΠΆΠΈΡΠΎΠ²ΠΎΠΉ Π±ΠΎΠ»Π΅Π·Π½ΡΡ ΠΏΠ΅ΡΠ΅Π½ΠΈ, ΡΡΠ΅Π°ΡΠΎΠ³Π΅ΠΏΠ°ΡΠΈΡΠΎΠΌ, Π΄Π²ΡΡΡΠΎΡΠΎΠ½Π½ΠΈΠΌ ΡΠΏΠΈΡΠΈΠ·ΠΈΠΎΠ»ΠΈΠ·ΠΎΠΌ ΡΠ°Π·ΠΎΠ±Π΅Π΄ΡΠ΅Π½Π½ΡΡ
ΡΡΡΡΠ°Π²ΠΎΠ² Π²ΠΎΠ·Π½ΠΈΠΊΠ»Π° ΠΏΠΎΡΠ»Π΅ ΡΠ΄Π°Π»Π΅Π½ΠΈΡ ΠΈΠ½ΡΡΠ°-ΡΠΊΡΡΡΠ°Π²Π΅Π½ΡΡΠΈΠΊΡΠ»ΡΡΠ½ΠΎΠΉ ΠΊΡΠ°Π½ΠΈΠΎΡΠ°ΡΠΈΠ½Π³Π΅ΠΎΠΌΡ Ρ ΡΠ΅Π±Π΅Π½ΠΊΠ° ΠΏΠΎΡΠ»Π΅ ΡΠ΄Π°Π»Π΅Π½ΠΈΡ ΠΏΠΎΡΠ»Π΅ ΡΠ΄Π°Π»Π΅Π½ΠΈΡ ΠΈΠ½ΡΡΠ°-ΡΠΊΡΡΡΠ°Π²Π΅Π½ΡΡΠΈΠΊΡΠ»ΡΡΠ½ΠΎΠΉ (ΡΡΠ΅Π±Π΅Π»ΡΠ½ΠΎΠΉ) ΠΊΡΠ°Π½ΠΈΠΎΡΠ°ΡΠΈΠ½Π³Π΅ΠΎΠΌΡ
Linguistic and statistically derived features for cause of death prediction from verbal autopsy text
Automatic Text Classification (ATC) is an emerging technology with economic importance given the unprecedented growth of text data. This paper reports on work in progress to develop methods for predicting Cause of Death from Verbal Autopsy (VA) documents recommended for use in low-income countries by the World Health Organisation. VA documents contain both coded data and open narrative. The task is formulated as a Text Classification problem and explores various combinations of linguistic and statistical approaches to determine how these may improve on the standard bag-of-words approach using a dataset of over 6400 VA documents that were manually annotated with cause of death. We demonstrate that a significant improvement of prediction accuracy can be obtained through a novel combination of statistical and linguistic features derived from the VA text. The paper explores the methods by which ATC may leads to improved accuracy in Cause of Death prediction
Large Anomalous Hall effect in a silicon-based magnetic semiconductor
Magnetic semiconductors are attracting high interest because of their
potential use for spintronics, a new technology which merges electronics and
manipulation of conduction electron spins. (GaMn)As and (GaMn)N have recently
emerged as the most popular materials for this new technology. While Curie
temperatures are rising towards room temperature, these materials can only be
fabricated in thin film form, are heavily defective, and are not obviously
compatible with Si. We show here that it is productive to consider transition
metal monosilicides as potential alternatives. In particular, we report the
discovery that the bulk metallic magnets derived from doping the narrow gap
insulator FeSi with Co share the very high anomalous Hall conductance of
(GaMn)As, while displaying Curie temperatures as high as 53 K. Our work opens
up a new arena for spintronics, involving a bulk material based only on
transition metals and Si, and which we have proven to display a variety of
large magnetic field effects on easily measured electrical properties.Comment: 19 pages with 5 figure
Studying the impact of ocean eddies on the ecosystem of the Prince Edward Islands: DEIMEC ll
The Dynamics of Eddy Impacts on Marionβs Ecosystem Study (DEIMEC) programme was begun in 2002 with the aim of understanding the importance of the oceanic, upstream environment to the ecosystem of the Prince Edward Islands. This island group consists of two small volcanic islands and provides many opportunities for studying ecological and evolutionary processes, for monitoring ecological changes in relation to global climate change and for conserving a unique component of the planetβs biological diversity
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