861 research outputs found
Хвороби колосу у озимої пшениці лісостепу України
Наводяться результати вивчення видового складу збудників хвороб колосу і зерна озимої пшениці. В результаті мікологічного аналізу визначили, що мікофлора хворого колосся представлена такими видами грибів: Mucor mucedo, Penicilium viridicatum, P. expansum, Alternaria alternata, A. tenussima, Cladosporium herbarum, Fusarium sporotrichiella, F.oxysporum, F. moniliforme, F. culmorum, F. graminearum, F. gibbosum. Серед грибів роду Fusarium найбільш поширеним є F. graminearum. До даного захворювання виділені відносно стійкі сорти: Деметра, Ростиславна, Багіра, Сніжана.Приводятся результаты изучения видового состава возбудителей болезней колоса и семян озимой пшеницы. В результате микологического анализа определили, что микофлора больных колосьев представлена такими видами грибов: Mucor mucedo, Penicillium viridicatum, P. expansum, Alternaria alternata, A. tenussima, Cladosporium herbarum, Fusarium sporotrichiella, F. oxysporum, F. moniliforme, F culmorum, F. graminearum, F. gibbosum. Среди грибов рода Fusarium наиболее распространенным является F. graminearum. К даному заболеванию выделены относительно устойчивые сорта: Деметра, Ростиславна, Багира, Снижана.Results of studying specific composition of pathogens of winter wheat head and seeds are given. Resulted from mycological analyze it was determined that mycoflora of attacked ears consists of such fungi species as Mucor mucedo, Penicillium viridicatum, P. expansum, Alternaria alternata, A. tenussima, Cladosporium herbarum, Fusarium sporotrichiella, F. oxysporum, F. moniliforme, F. culmorum, F. graminearum, F. gibbosum. F. graminerum was the most widespread species among Fusarium genus. Comparatively resistant against these disease cultivars Demetra, Rostyslavna, Bagira, Snizhana were singled out
До проблеми вивчення весілля Шевченкового краю (за матеріалами передвесільної обрядовості)
While businesses may attract potential offenders and thus be conducive to
disorder, the number of employees could offset this by exercising social
control on offenders. This study uses data from different sources to test
this expectation across 278 Dutch neighborhoods in the four largest cities
of the Netherlands, using multivariate multilevel analysis to disentangle
individual perception differences of disorder and neighborhood effects.
Attention is paid to traditional explanations of disorder (i.e., poverty, residential
mobility, and ethnic heterogeneity). Results show a positive relationship
between business presence and neighborhood disorder. We do not find
consistent results of the number of employees (i.e., bigger businesses are
not always better or worse). Our research demonstrates that the presence of neighborhood businesses could rival the effects of social disorganization
theory
Local Surface Density of the Galactic Disk from a 3-D Stellar Velocity Sample
We have re-estimated the surface density of the Galactic disk in the solar
neighborhood within 0.4 kpc of the Sun using parallaxes and proper
motions of a kinematically and spatially unbiased sample of 1476 old bright red
giant stars from the Hipparcos catalog with measured radial velocities from
Barbier-Brossat & Figon (2000). We determine the vertical distribution of the
red giants as well as the vertical velocity dispersion of the sample, (14.4
0.26 km/sec), and combine these to derive the surface density of
gravitating matter in the Galactic disk as a function of the galactic
coordinate . The surface density of the disk increases from 10.5 0.5
/ pc within 50 pc to 42 6 / pc
within 350 pc. The estimated volume density of the galactic disk within
50 pc is about 0.1 / pc which is close to the volume
density estimates of the observed baryonic matter in the solar neighborhood.Comment: 24 pages, 15 figures, AJ in pres
Are Compact High-Velocity Clouds Extragalactic Objects?
Compact high-velocity clouds (CHVCs) are the most distant of the HVCs in the
Local Group model and would have HI volume densities of order 0.0003/cm^3.
Clouds with these volume densities and the observed neutral hydrogen column
densities will be largely ionized, even if exposed only to the extragalactic
ionizing radiation field. Here we examine the implications of this process for
models of CHVCs. We have modeled the ionization structure of spherical clouds
(with and without dark matter halos) for a large range of densities and sizes,
appropriate to CHVCs over the range of suggested distances, exposed to the
extragalactic ionizing photon flux. Constant-density cloud models in which the
CHVCs are at Local Group distances have total (ionized plus neutral) gas masses
roughly 20-30 times larger than the neutral gas masses, implying that the gas
mass alone of the observed population of CHVCs is about 40 billion solar
masses. With a realistic (10:1) dark matter to gas mass ratio, the total mass
in such CHVCs is a significant fraction of the dynamical mass of the Local
Group, and their line widths would exceed the observed FWHM. Models with dark
matter halos fare even more poorly; they must lie within approximately 200 kpc
of the Galaxy. We show that exponential neutral hydrogen column density
profiles are a natural consequence of an external source of ionizing photons,
and argue that these profiles cannot be used to derive model-independent
distances to the CHVCs. These results argue strongly that the CHVCs are not
cosmological objects, and are instead associated with the Galactic halo.Comment: 30 pages, 14 figures; to appear in The Astrophysical Journa
Functional Polycentrism and Urban Network Development in the Greater South East UK: Evidence from Commuting Patterns, 1981-2001
In contemporary literature on changing urban systems, it is often argued that the traditional central place conceptualisation is outdated and should be replaced by a network view that emphasises the increasing criss-crossing pattern of interdependencies between spatial units. This paper tests for urban network development by looking at commuting patterns in the Greater South East UK. The analysis is based on census commuting interaction data for three points in time during the past three decades (1981, 1991, and 2001). Although the empirical results indicate that the Greater South East UK can still not be characterized as a polycentric urban region or integrated urban network, there is some evidence for urban network development at the local, intra-urban, level as well as a decentralization of the system at the regional, inter-urban, level
Childhood Characteristics of Adolescent Inpatients with Early-Onset and Adolescent-Onset Disruptive Behavior
Childhood characteristics are associated with life-course-persistent antisocial behavior in epidemiological studies in general population samples. The present study examines this association in an inpatient sample. The purpose is to identify easily measurable childhood characteristics that may guide choice of treatment for adolescent psychiatric inpatients with severe disruptive behavior. Patients (N = 203) were divided into two groups with either early-onset (EO) or adolescent-onset (AO) disruptive behavior, based on ages at which professional care was used for disruptive behavior, referral to special education, and criminal offences. Both groups differed on several childhood characteristics. No gender differences in these characteristics were found. Logistic regression analysis indicated that individuals with grade retention in primary school, childhood impulsive behavior, and a history of physical abuse, had the highest probability of being member of the EO group. These characteristics are reasonably easy to identify, likely apply to other clinical samples as well, and may help clinicians to target their treatment
High-resolution 21-cm observations of low-column density gas clumps in the Milky Way halo
We study the properties of low-column density gas clumps in the halo of the
Milky Way based on high-resolution 21-cm observations.
Using interferometric data from the WSRT and the VLA we study HI emission at
low-, intermediate- and high radial velocities along four lines of sight
towards quasars. Along these sightlines we previously detected weak CaII and
NaI absorbers in their optical spectra.
The analysis of the high-resolution HI data reveals the presence of several
compact and cold clumps of neutral gas at velocities similar to the optical
absorption. The clumps have narrow HI line widths in the range of 1.8 to 13
km/s, yielding upper limits for the kinetic temperature of the gas of 70 to
3700 K. The neutral gas has low HI column densities in the range of 5E18 to
3E19 1/cm^2. All clumps have angular sizes of only a few arcminutes.
Our high-resolution 21-cm observations indicate that many of the CaII and NaI
absorbers seen in our optical quasar spectra are associated with low-column
density HI clumps at small angular scales. This suggests that next to the
massive, high-column density neutral gas clouds in the halo (the common 21-cm
LVCs, IVCs, and HVCs) there exists a population of low-mass, neutral gas
structures in the halo that remain mostly unseen in the existing 21-cm all-sky
surveys of IVCs and HVCs. The estimated thermal gas pressures of the detected
HI clumps are consistent with what is expected from theoretical models of gas
in the inner and outer Milky Way halo.Comment: 12 pages, 7 figure
Open cluster survival within the solar circle: Teutsch145 and Teutsch146
Teutsch145 and Teutsch146 are shown to be open clusters (OCs) orbiting well
inside the Solar circle, a region where several dynamical processes combine to
disrupt most OCs on a time-scale of a few 10^8yrs. BVI photometry from the
GALILEO telescope is used to investigate the nature and derive the fundamental
and structural parameters of the optically faint and poorly-known OCs
Teutsch145 and 146. These parameters are computed by means of field-star
decontaminated colour-magnitude diagrams (CMDs) and stellar radial density
profiles (RDPs). Cluster mass estimates are made based on the intrinsic mass
functions (MFs). We derive the ages 200+100-50Myr and 400+/-100Myr, and the
distances from the Sun 2.7+/-0.3kpc and 3.8+/-0.2kpc, respectively for
Teutsch145 and 146. Their integrated apparent and absolute magnitudes are m_V ~
12.4, m_V ~ 13.3, M_V ~- 5.6 and M_V ~- 5.3. The MFs (detected for stars with
m>1Msun) have slopes similar to Salpeter's IMF. Extrapolated to the H-burning
limit, the MFs would produce total stellar masses of ~1400Msun, typical of
relatively massive OCs. Both OCs are located deep into the inner Galaxy and
close to the Crux-Scutum arm. Since cluster-disruption processes are important,
their primordial masses must have been higher than the present-day values. The
conspicuous stellar density excess observed in the innermost bin of both RDPs
might reflect the dynamical effects induced by a few 10^8yrs of external tidal
stress.Comment: 8 pagas with 9 figs. Accepted by MNRA
Picosecond Fluorescence Relaxation Spectroscopy of the Calcium-Discharged Photoproteins Aequorin and Obelin
Addition of calcium ions to the Ca2+-regulated photoproteins, such as aequorin and obelin, produces a blue bioluminescence originating from a fluorescence transition of the protein-bound product, coelenteramide. The kinetics of several transient fluorescent species of the bound coelenteramide is resolved after picosecond-laser excitation and streak camera detection. The initially formed spectral distributions at picosecond-times are broad, evidently comprised of two contributions, one at higher energy (25000 cm-1) assigned as from the Ca2+-discharged photoprotein-bound coelenteramide in its neutral state. This component decays much more rapidly (t1/2 2 ps) in the case of the Ca2+-discharged obelin than aequorin (t1/2 30 ps). The second component at lower energy shows several intermediates in the 150-500 ps times, with a final species having spectral maxima 19400 cm-1, bound to Ca2+-discharged obelin, and 21300 cm-1, bound to Ca2+-discharged aequorin, and both have a fluorescence decay lifetime of 4 ns. It is proposed that the rapid kinetics of these fluorescence transients on the picosecond time scale, correspond to times for relaxation of the protein structural environment of the binding cavit
Proposals for evaluating the regularity of a scientist'sresearch output
Evaluating the career of individual scientists according to their scientific output is a common bibliometric problem. Two aspects are classically taken into account: overall productivity and overall diffusion/impact, which can be measured by a plethora of indicators that consider publications and/or citations separately or synthesise these two quantities into a single number (e.g. h-index). A secondary aspect, which is sometimes mentioned in the rules of competitive examinations for research position/promotion, is time regularity of one researcher's scientific output. Despite the fact that it is sometimes invoked, a clear definition of regularity is still lacking. We define it as the ability of generating an active and stable research output over time, in terms of both publications/ quantity and citations/diffusion. The goal of this paper is introducing three analysis tools to perform qualitative/quantitative evaluations on the regularity of one scientist's output in a simple and organic way. These tools are respectively (1) the PY/CY diagram, (2) the publication/citation Ferrers diagram and (3) a simplified procedure for comparing the research output of several scientists according to their publication and citation temporal distributions (Borda's ranking). Description of these tools is supported by several examples
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