1,193 research outputs found
Obpanonska prozodijska vzporednica na besedni ravni: paroksitoneza v jugozahodnem ÄeĆĄkem nareÄju
Slavists generally think of the Czecho-Slovak dialect area as having a wordprosody
configuration of fixed word-initial stress with contrastive length possible in any syllable. A notable exception is the Silesian dialect area, which typically has the Polish configuration with fixed penultimate stress and no contrastive length. Much less familiar is a small area in SW Bohemia (Pilsen, ÄeskĂ© BudÄjovice and environs) with what has been termed âparoxytonic stressâ and contrastive length, which at first blush may be considered akin to the Silesian configuration
k-Spectra of weakly-c-Balanced Words
A word is a scattered factor of if can be obtained from by
deleting some of its letters. That is, there exist the (potentially empty)
words , and such that and
. We consider the set of length- scattered
factors of a given word w, called here -spectrum and denoted
\ScatFact_k(w). We prove a series of properties of the sets \ScatFact_k(w)
for binary strictly balanced and, respectively, -balanced words , i.e.,
words over a two-letter alphabet where the number of occurrences of each letter
is the same, or, respectively, one letter has -more occurrences than the
other. In particular, we consider the question which cardinalities n=
|\ScatFact_k(w)| are obtainable, for a positive integer , when is
either a strictly balanced binary word of length , or a -balanced binary
word of length . We also consider the problem of reconstructing words
from their -spectra
Air-sea interaction in the tropical Pacific Ocean
Charts of 3-month sea surface temperature (SST) anomalies in the eastern tropical Pacific Ocean were produced for the period 1949 to 1970. The anomalies along the United States and South American west coasts and in the eastern tropical Pacific appeared to be oscillating in phase during this period. Similarly, the satellite-derived cloudiness for each of four quadrants of the Pacific Ocean (130 deg E to 100 deg W, 30 deg N to 25 deg S) appeared to be oscillating in phase. In addition, a global tropical cloudiness oscillation from 30 deg N to 30 deg S was noted from 1965 to 1970, by using monthly satellite television nephanalyses. The SST anomalies were found to have a good degree of correlation both positive and negative with the following monthly geophysical parameters: (1) satellite-derived cloudiness, (2) strength of the North and South Pacific semipermanent anticyclones, (3) tropical Pacific island rainfall, and (4) Darwin surface pressure. Several strong direct local and crossequatorial relationships were noted. In particular, the high degree of correlation between the tropical island rainfall and the SST anomalies (r = +0.93) permitted the derivation of SST's for the tropical Pacific back to 1905. The close occurrence of cold tropical SST and North Pacific 700-mb positive height anomalies with central United States drought conditions was noted
Report on a Symposium âIslam and the Changing Identity of Europeâ
In October 1998, The Middle East and West Europe Centers of the University of California at Berkeley jointly sponsored a two-day symposium, âIslam and the Changing Identity of Europe: Culture, Politics and Citizenship in an Era of Globalizationâ. The programme focused on the deep ideational changes which have been taking place in Europe due to the Muslim populations which have sprung up in the United Kingdom, France, Germany and elsewhere. The symposium explored political and cultural aspects of the emerging identities of these relatively new citizens Ă how they view themselves and how they are viewed by non-Muslim Europeans, as well as how the relatively indigenous populations of Europe are being forced to rethink their own collective identities, both as Europeans and as citizens of specific countries. In their symposium prospectus and introductory remarks the organizers argued that these are no longer migration issues in the traditional sense, because most Muslims in Europe are no longer migrants. Muslim populations have been present in Europe for several generations, although many Europeans have been slow to recognize that Islam is now a European religion
The molecular basis of host specialization in bean pathovars of Pseudomonas syringae
Biotrophic phytopathogens are typically limited to their
adapted host range. In recent decades, investigations have
teased apart the general molecular basis of intraspecific
variation for innate immunity of plants, typically involving
receptor proteins that enable perception of pathogen-associated
molecular patterns or avirulence elicitors from the
pathogen as triggers for defense induction. However, general
consensus concerning evolutionary and molecular factors
that alter host range across closely related phytopathogen
isolates has been more elusive. Here, through genome
comparisons and genetic manipulations, we investigate the
underlying mechanisms that structure host range across
closely related strains of Pseudomonas syringae isolated
from different legume hosts. Although type III secretionindependent
virulence factors are conserved across these
three strains, we find that the presence of two genes encoding
type III effectors (hopC1 and hopM1) and the absence
of another (avrB2) potentially contribute to host range differences
between pathovars glycinea and phaseolicola.
These findings reinforce the idea that a complex genetic
basis underlies host range evolution in plant pathogens.
This complexity is present even in hostâmicrobe interactions
featuring relatively little divergence among both hosts
and their adapted pathogens
Natural history of Arabidopsis thaliana and oomycete symbioses
Molecular ecology of plantâmicrobe interactions has immediate significance for filling a gap in knowledge between the laboratory discipline of molecular biology and the largely theoretical discipline of evolutionary ecology. Somewhere in between lies conservation biology, aimed at protection of habitats and the diversity of species housed within them. A seemingly insignificant wildflower called Arabidopsis thaliana has an important contribution to make in this endeavour. It has already transformed botanical research with deepening understanding of molecular processes within the species and across the Plant Kingdom; and has begun to revolutionize plant breeding by providing an invaluable catalogue of gene sequences that can be used to design the most precise molecular markers attainable for marker-assisted selection of valued traits. This review describes how A. thaliana and two of its natural biotrophic parasites could be seminal as a model for exploring the biogeography and molecular ecology of plantâmicrobe interactions, and specifically, for testing hypotheses proposed from the geographic mosaic theory of co-evolution
On Maximal Unbordered Factors
Given a string of length , its maximal unbordered factor is the
longest factor which does not have a border. In this work we investigate the
relationship between and the length of the maximal unbordered factor of
. We prove that for the alphabet of size the expected length
of the maximal unbordered factor of a string of length~ is at least
(for sufficiently large values of ). As an application of this result, we
propose a new algorithm for computing the maximal unbordered factor of a
string.Comment: Accepted to the 26th Annual Symposium on Combinatorial Pattern
Matching (CPM 2015
Chestnut-crowned babbler calls are composed of meaningless shared building blocks
A core component of human language is its combinatorial sound system: meaningful signals are built from different combinations of meaningless sounds. Investigating whether non-human communication systems are also combinatorial is hampered by difficulties in identifying the extent to which vocalizations are constructed from shared, meaningless building blocks. Here we present a novel approach to circumvent this difficulty and show that a pair of functionally distinct chestnut-crowned babbler (Pomatostomus ruficeps) vocalizations can be decomposed into perceptibly distinct, meaningless entities that are shared across the two calls. Specifically, by focusing on the acoustic distinctiveness of sound elements using a habituation-discrimination paradigm on wild-caught babblers under standardized aviary conditions, we show that two multi-element calls are composed of perceptibly distinct sounds that are reused in different arrangements across the two calls. Furthermore, and critically, we show that none of the five constituent elements elicits functionally relevant responses in receivers, indicating that the constituent sounds do not carry the meaning of the call; so are contextually meaningless. Our work, which allows combinatorial systems in animals to be more easily identified, suggests that animals can produce functionally distinct calls that are built in a way superficially reminiscent of the way that humans produce morphemes and words. The results reported lend credence to the recent idea that languageâs combinatorial system may have been preceded by a superficial stage where signalers neither needed to be cognitively aware of the combinatorial strategy in place, nor of its building blocks
Determinants of polyp Size in patients undergoing screening colonoscopy
<p>Abstract</p> <p>Background</p> <p>Pre-existing polyps, especially large polyps, are known to be the major source for colorectal cancer, but there is limited available information about factors that are associated with polyp size and polyp growth. We aim to determine factors associated with polyp size in different age groups.</p> <p>Methods</p> <p>Colonoscopy data were prospectively collected from 67 adult gastrointestinal practice sites in the United States between 2002 and 2007 using a computer-generated endoscopic report form. Data were transmitted to and stored in a central data repository, where all asymptomatic white (n = 78352) and black (n = 4289) patients who had a polyp finding on screening colonoscopy were identified. Univariate and multivariate analysis of age, gender, performance site, race, polyp location, number of polyps, and family history as risk factors associated with the size of the largest polyp detected at colonoscopy.</p> <p>Results</p> <p>In both genders, size of the largest polyp increased progressively with age in all age groups (<it>P </it>< .0001). In subjects â„ 80 years the relative risk was 1.55 (95% CI, 1.35-1.79) compared to subjects in the youngest age group. With the exception of family history, all study variables were significantly associated with polyp size (<it>P </it>< .0001), with multiple polyps (â„ 2 versus 1) having the strongest risk: 3.41 (95% CI, 3.29-3.54).</p> <p>Conclusions</p> <p>In both genders there is a significant increase in polyp size detected during screening colonoscopy with increasing age. Important additional risk factors associated with increasing polyp size are gender, race, polyp location, and number of polyps, with polyp multiplicity being the strongest risk factor. Previous family history of bowel cancer was not a risk factor.</p
Unusual cage rearrangements in 10-vertex nido-5,6-dicarbaborane derivatives : An interplay between theory and experiment
The reaction between selected X-nido-5,6-C2B8H11 compounds (where X = Cl, Br, I) and "Proton Sponge" [PS; 1,8-bis(dimethylamino)naphthalene], followed by acidification, results in extensive rearrangement of all cage vertices. Specifically, deprotonation of 7-X-5,6-C2B8H11 compounds with one equivalent of PS in hexane or CH2Cl2 at ambient temperature led to a 7 â 10 halogen rearrangement, forming a series of PSH+[10-X-5,6-C2B8H10]- salts. Reprotonation using concentrated H2SO4 in CH2Cl2 generates a series of neutral carbaboranes 10-X-5,6-C2B8H11, with the overall 7 â 10 conversion being 75%, 95%, and 100% for X = Cl, Br, and I, respectively. Under similar conditions, 4-Cl-5,6-C2B8H11 gave âŒ66% conversion to 3- Cl-5,6-C2B8H11. Since these rearrangements could not be rationalized using the Bvertex swing mechanism, new cage rearrangement mechanisms, which are substantiated using DFT calculations, have been proposed. Experimental 11B NMR chemical shifts are well reproduced by the computations; as expected ÎŽ(11B) for B(10) atoms in derivatives with X = Br and I are heavily affected by spin-orbit coupling
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