843 research outputs found
A fractional kinetic process describing the intermediate time behaviour of cellular flows
This paper studies the intermediate time behaviour of a small random perturbation of a periodic cellular flow. Our main result shows that on time scales shorter than the diffusive time scale, the limiting behaviour of trajectories that start close enough to cell boundaries is a fractional kinetic process: A Brownian motion time changed by the local time of an independent Brownian motion. Our proof uses the Freidlin-Wentzell framework, and the key step is to establish an analogous averaging principle on shorter time scales. As a consequence of our main theorem, we obtain a homogenization result for the associated advection-diffusion equation. We show that on intermediate time scales the effective equation is a fractional time PDE that arises in modelling anomalous diffusion
Mikroszatellita lokuszok evolúciója a görögdinnyében (Citrullus lanatus) a középkor óta; (CT)3 deléció a (CT)26 nSSR-ban.
Görögdinnye (Citrullus lanatus) magleletekből (13. sz.,
Debrecen; 15. sz. Buda; 18. sz. Pannonhalma) DNS-izolálást,
molekuláris (nSSR – nuclear simple sequence repeat; cpDNS –
kloroplasztisz DNS) elemzést és fenotípusos fajtarekonstrukciót
végeztünk 44 mai fajtával való összehasonlításban. Az elemzésben
47 primer-párt teszteltünk, ebből 26 primer-pár bizonyult
hatékonynak a mai fajtákban, amelyek közül csak 16 volt aktív a
középkori mintában. Az aktív primerek alkalmazásával szekvencia
elemzést végeztünk a (CT)26-30 nSSR lokuszon, és a clp-12 cpDNS
lokuszon. Megállapítottuk, hogy a középkori mintában még
megtalálható (CT)3 szakasz a mai fajtában már delécióval kiesett
az elmúlt 600 év során. Továbbá a cpDNS trnV (Jarret et al.,
1997) lokuszán (tRNS-Valin; 299 bp) két szubsztitúciót
azonosítottunk (102.196 és a 102.201 nt.-ben). A (CT)26-30 nSSR
lokusz (196 bp) 122-130 bp szakaszán egy további (CT)4 inverziót
is azonosítottunk, amely (CT)26-30 egyszerű mikroszatellita
lokuszból kialakuló (CT)17-C-(TC)3-T-(CT)5 összetett
mikroszatellita születését igazolja. Vizsgálataink során egy új
retrotranszpozont (Cila-1) azonosítottunk. A középkori minta
fajtarekonstrukciójához elkészítettük a 44 mai fajta morfológiai
dendrogramját 25 fenotípusos bélyeg alapján. | The evolution of water melon (Citrullus lanatus)
microsatellites from the 15th century (Debrecen); 13th (Buda); and
18th century, (Pannonhalma) were analyzed. Microsatellite (nSSR,
nuclear simple sequence repeat) and cpDNA profiles of the aDNA
(ancient DNA) of seed remains were compared to modern water
melon cultivars and landraces. Sixteen primer pairs were applied.
Sequence analysis at the (CT)26 and cpDNA trnV loci revealed a
(CT)3 and Adenin deletions, respectively, form the current water
melon cultivar compared to the medieval sample. Cila-1), a new
LTR retrotansposon has been described. For morphological
reconstruction, a dendrogram produced by SPSS11 based on the
presence versus absence of 24 phenotypic characters were also
analyzed
Comparative investigation of damage induced by diatomic and monoatomic ion implantation in silicon
The damaging effect of mono- and diatomic phosphorus and arsenic ions implanted into silicon was investigated by spectroscopic ellipsometry (SE) and high-depth-resolution Rutherford backscattering and channeling techniques. A comparison was made between the two methods to check the capability of ellipsometry to examine the damage formed by room temperature implantation into silicon. For the analysis of the spectroscopic ellipsometry data we used the conventional method of assuming appropriate optical models and fitting the model parameters (layer thicknesses and volume fractions of the amorphous silicon component in the layers) by linear regression. The depth dependence of the damage was determined by both methods. It was revealed that SE can be used to investigate the radiation damage of semiconductors together with appropriate optical model construction which can be supported or independently checked by the channeling method. However, in case of low level damage (consisting mainly of isolated point defects) ellipsometry can give false results, overestimating the damage using inappropriate dielectric functions. In that case checking by other methods like channeling is desirable
Morfológiai diverzitás sárgadinnyében (Cucumis melo); egy középkori típus fajtarekonstrukciója
47 mai sárgadinnye tájfajta illetve fajta morfológiai diverzitás
vizsgálatát végeztük el 23 fenotípusos bélyeg alapján, egy
középkori lelet (15. sz. eleje) rekonstrukciójához, valamint az eltet
600 év során végbement mikroevolúciós folyamatok
nyomonkövetésére. A vizsgálatok során felvételezett 47 mai
sárgadinnye fajta kivétel nélkül besorolható volt az Európában
elterjedt három fő terméstípusú csoportba: a cikkelyesen barázdás
Kantalup (cantalupensis), a hálózatos-recés terméshéjú
Retikulatusz (reticulatus), és a simahéjú Inodorusz (inodorus)
csoportba. A párhuzamosan végzett molekuláris vizsgálatok,
valamint az itt közölt morfológiai diagramm segítségével a
középkori minta fajta-típusa meghatározható volt, amely egy
inodorusz típusú, sima héjú, zöld húsú sárgadinnye lehetett,
átmeneti formával a „Hógolyó” és a „Kősárga” tájfajta között. | Morphological diversity of melon (Cucumis melo); phenotype
reconstruction of a medieval sample. Morphological diversity
among 47 melon (Cucumis melo) cultivars and landraces from
Hungarian germplasm collection (ABI, Tápiószele) were analyzed
with an ultimate aim to characterize morphologically cv. Hógolyó,
which showed the closest genetic similarity to a medieval melon
recovered from the 15th century. Cultivars based on fruit
morphology were grouped into the three main types of melon as
reticulatus, cantalupensis and inodorus. Cluster analysis (by
SPSS-11) based on 23 morphological (quantitative and
qualitative) traits recorded revealed an extreme diversity among
accessions, nevertheless cultivars were clustered into main melon
clusters with only two exceptions of inodorus type cv. Zimovka J.
and Afghanistan. Cultivars Sweet ananas and Ezüst ananász; and
two Hungarian landraces Kisteleki and Nagycserkeszi showed
close similarity. Cultivars Hógolyó and Túrkeve of inodorus type
were also grouped in one cluster, which provide insight into the
morphological reconstruction of the medieval melon recovered
from the 15th century. These results also indicate that old
Hungarian landraces could be re-introduced into breeding
programs for broadening genetic base of melon
CALIBRATION OF SIMS MEASUREMENTS BY ION IMPLANTATION
The paper reviews some joint results of the above institutions in quantitative SIMS
(Secondary Ion Mass Spectrometry) analysis of implanted dopants. Quantification of the SIMS
was achieved by implanting marker ions as standards prior to analysis. Feasibility of this
technique was first demonstrated by Giber et al. (1982). Further considerations will be presented
Kinetics of TiSi2 formation by thin Ti films on Si
Silicide formation with Ti deposited on single crystal Si and Ti deposited on amorphous Si layers sequentially without breaking the vacuum was investigated using backscattering spectrometry and glancing-angle x-ray diffraction. For Ti deposited on amorphous Si, TiSi2 was formed with a rate proportional to (time)^1/2 and an activation energy of 1.8±0.1 eV. For Ti deposited on single crystal Si, the reaction rate was slower and the silicide layer was nonuniform in thickness. We attribute the difference in behavior to the presences of interfacial impurities in the case where Ti was deposited on single crystal Si
SSR- and RAPD Analysis of a New Agropyron Repens Genotype
SSR-(single sequence repeat), and RAPD (randomly amplified polymorphic DNA) primer generated DNA fingerprints were used to distinguish a new genotype of quackgrass from its original type of Agropyron repenes L. Beauv. (= Elytrigia repens). Products of polymerase chain reactions (PCR) were separated by agarose (AGE) and denaturing gradient gel electrophoresis (DGGE). Although, both kinds of primers were found to be polymorphic, the microsatellite primer with sequence of 5í-AC(GACA)4-3í generated distinguishing fingerprints in the two types of quackgrasses. This result gives genetic evidence for the new genotype of quackgrass
Current practice of methotrexate use for psoriasis: results of a worldwide survey among dermatologists
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