54 research outputs found
School Administrators’ and Regular Classroom Teachers’ Attitudes and Perceptions on In-Service Training Related to Mainstreaming Mildly Handicapped Pupils
P.L. 94-142 (The Education for All Handicapped Children Act of 1975) requires that a comprehensive system of in-service training must be implemented to assist regular educators meet the challenge of educating the mildly handicapped in the regular classroom. Relative to the required in-service as stated in P.L. 94-142, this study had two goals (1) to measure the attitudes and perceptions of school administrators and regular classroom teachers toward in-service development related to mainstreaming and (2) to study problem areas associated with conducting such in-service.
The study was conducted in a nine county rural area in North central Iowa. The population included all Northern Trails Area Education Agency II school administrators and a 10 percent random sample of AEA II regular classroom teachers at each the elementary and secondary level. The combined populations totaled 278.
A questionnaire was employed, soliciting educator responses to (1) attitudes and perceptions toward in-service activities
related to mainst:.eamin0, (2) the most appropriate length of in-service, (3) the most appropriate people to conduct the in-service, (4) the preferred format for in-service and (5) problems related to conducting such in-service. Chi-square results were obtained for sections of the questionnaire where Chi-square application was appropriate. Responses were tabulated by frequency and percentages for all sections of the questionnaire.
Results of the study, as taken from the selected population, indicated that (1} attitudinal and perceptual differences exist between school administrator and regular teachers on in-service training, (2} attitudinal and perceptual differences are minimal between elementary and secondary teachers related to in-service training, (3) both groups preferred in-service which is half-day or a full day in length, (4) both groups preferred in-service activities which are demonstration and activity-centered and {5} the most appropriate people preferred to conduct the in-service are AEA II personnel and special education teachers.
Problems verified by the findings of the study included teachers attending in-service: (1) with released time and pay, {2) in the evening with pay, (3) on weekends with pay, {4) during the summer with extended contract, and (5) the hiring of substitutes to allow teachers to attend in-service during the regular working hours.
The implications for further research suggested additional study be conducted in the areas of (1) comparative studies on a statewide basis, (2) actual knowledge of educators rather than perceived levels of in-service topics related to mainstreaming, and (3) the effects master contracts have on in-service training programs
Near-IR 2D-Spectroscopy of the 4''x 4'' region around the Active Galactic Nucleus of NGC1068 with ISAAC/VLT
We present new near-IR long slit spectroscopic data obtained with ISAAC on
VLT/ANTU (ESO/Paranal) of the central 4''x 4'' region surrounding the central
engine of NGC1068 . Bracket Gamma (Bg) and H2 emission line maps and line
profile grids are produced, at a spatial resolution~0.5" and spectral
resolution 35km/s. Two conspicuous knots of H2 emission are detected at about
1'' on each side of the central engine along PA=90deg, with a projected
velocity difference of 140km/s: this velocity jump has been interpreted in
Alloin et al (2001) as the signature of a rotating disk of molecular material.
Another knot with both H2 and Bg emission is detected to the North of the
central engine, close to the radio source C where the small scale radio jet is
redirected and close to the brightest [OIII] cloud NLR-B. At the achieved
spectral resolution, the H2 emission line profiles appear highly asymmetric
with their low velocity wing being systematically more extended than their high
velocity wing. A simple way to account for the changes of the H2 line profiles
(peak-shift with respect to the systemic velocity, width, asymmetry) over the
entire 4''x 4'' region, is to consider that a radial outflow is superimposed
over the emission of the rotating molecular disk. We present a model of such a
kinematical configuration and compare our predicted H2 emission profiles to the
observed ones.Comment: 15 pages, 11 figures, accepted for publication in A&
Molecular Hydrogen and [FeII] in Active Galactic Nuclei
(Abridge) Near-infrared spectroscopy is used to study the kinematics and
excitation mechanisms of the H2 and [FeII] gas in a sample of AGN. The H2 lines
are unresolved in all objects in which they were detected while the [FeII]
lines have widths implying gas velocities of up to 650 km/s. This suggests
that, very likely, the H2 and [FeII] emission does not originate from the same
parcel of gas. Molecular H2 were detected in 90% of the sample, including PG
objects, indicating detectavel amounts of molecular material even in objects
with low levels of circumnuclear starburst activity. The data favors thermal
excitation for the H2 lines. Indeed, in NGC3227, Mrk766, NGC4051 and NGC4151,
the molecular emission is found to be purely thermal. This result is also
confirmed by the rather similar vibrational and rotational temperatures in the
objects for which they were derived. [FeII] lines are detected in all of the
AGN. The [FeII] 1.254mu/Pa-beta ratio is compatible with excitation of the
[FeII] by the active nucleus, but in Mrk 766 it implies a stellar origin. A
correlation between H2/Br-gamma and [FeII]/Pa-beta is found. We confirm that it
is a useful diagnostic tool in the NIR to separate emitting line objects by
their level of nuclear activity. X-ray excitation models are able to explain
the observed H2 and part of the [FeII] emission. Most likely, a combination of
X-ray heating, shocks driven by the radio jet, and circumnuclear star formation
contributes, in different proportions, to the H2 and [FeII] emission. In most
of our spectra, the [FeII] 1.257mu/1.644mu ratio is found to be 30% lower than
the intrinsic value based on current atomic data. This implies either than the
extinction towards the [FeII] emitting clouds is very similar in most objects
or there are possible inaccuracies in the A-values in the [FeII] transitions.Comment: 18 pages, 6 figures, Accepted for publication in Astronomy &
Astrophysic
Impaired Neurofilament Integrity and Neuronal Morphology in Different Models of Focal Cerebral Ischemia and Human Stroke Tissue
As part of the neuronal cytoskeleton, neurofilaments are involved in maintaining cellular integrity. In the setting of ischemic stroke, the affection of the neurofilament network is considered to mediate the transition towards long-lasting tissue damage. Although peripheral levels of distinct neurofilament subunits are shown to correlate with the clinically observed severity of cerebral ischemia, neurofilaments have so far not been considered for neuroprotective approaches. Therefore, the present study systematically addresses ischemia-induced alterations of the neurofilament light (NF-L), medium (NF-M), and heavy (NF-H) subunits as well as of α-internexin (INA). For this purpose, we applied a multi-parametric approach including immunofluorescence labeling, western blotting, qRT-PCR and electron microscopy. Analyses comprised ischemia-affected tissue from three stroke models of middle cerebral artery occlusion (MCAO), including approaches of filament-based MCAO in mice, thromboembolic MCAO in rats, and electrosurgical MCAO in sheep, as well as human autoptic stroke tissue. As indicated by altered immunosignals, impairment of neurofilament subunits was consistently observed throughout the applied stroke models and in human tissue. Thereby, altered NF-L immunoreactivity was also found to reach penumbral areas, while protein analysis revealed consistent reductions for NF-L and INA in the ischemia-affected neocortex in mice. At the mRNA level, the ischemic neocortex and striatum exhibited reduced expressions of NF-L- and NF-H-associated genes, whereas an upregulation for Ina appeared in the striatum. Further, multiple fluorescence labeling of neurofilament proteins revealed spheroid and bead-like structural alterations in human and rodent tissue, correlating with a cellular edema and lost cytoskeletal order at the ultrastructural level. Thus, the consistent ischemia-induced affection of neurofilament subunits in animals and human tissue, as well as the involvement of potentially salvageable tissue qualify neurofilaments as promising targets for neuroprotective strategies. During ischemia formation, such approaches may focus on the maintenance of neurofilament integrity, and appear applicable as co-treatment to modern recanalizing strategies
Feeding versus Feedback in NGC 4151 probed with Gemini NIFS. I. Excitation
We have used the Gemini Near-infrared Integral Field Spectrograph (NIFS) to
map the emission-line intensity distributions and ratios in the Narrow-Line
Region (NLR) of the Seyfert galaxy NGC 4151 in the Z, J, H and K bands at a
resolving power ~ 5000, covering the inner 200 pc x 300 pc of the galaxy at a
spatial resolution of 8 pc. We present intensity distributions I(r) in 14
emission lines. (1) For the ionized gas, I(r) is extended to ~ 100 pc from the
nucleus along pos. angle PA=60/240 deg-- NE--SW), consistent with an origin in
the known biconical outflow; while for the recombination lines I(r) ~ r^-1, for
the forbidden lines I(r) is flat (r^0). (2) The H_2 emission lines intensity
distributions avoid the region of the bicone, extending to r ~ 60 pc,
perpendicular to the bicone axis, supporting an origin for the H_2-emitting gas
in the galaxy plane. (3) The coronal lines show a steep intensity profile,
described by r^-2. Using the line-ratio maps [Fe II]1.644/1.257 and Pa_b/Br_g
we obtain a reddening of E(B-V)~0.5 along the NLR and E(B-V)>1 at the nucleus.
Our line-ratio map [Fe II] 1.257/[P II] 1.189 is the first such map of an
extragalactic source. Together with the [Fe II]/Pa_b map, these line ratios
correlate with the radio intensity distribution, mapping the effects of shocks
produced by the radio jet, which probably release the Fe locked in grains and
produce the enhancement of the [Fe II] emission observed at ~ 1 arcsec from the
nucleus. At these regions, we obtain densities N_e ~4000 cm^-3 and temperatures
T_e ~ 15000K for the [Fe II]-emitting gas. For the H_2-emitting gas we obtain T
~ 2100K. The distinct intensity distributions, physical properties and
locations of the ionized and molecular gas suggest that the H_2-emitting gas
traces the AGN feeding, while the ionized gas traces its feedback.Comment: 22 pages. 14 figures, accepted for publication in MNRA
Near-infrared [Fe II] emission from supernova remnants and the supernova rate of starburst galaxies
In an effort to better calibrate the supernova rate of starburst galaxies as
determined from near-IR [Fe II] features, we report on a [Fe II] 1.644 microns
line-imaging survey of a sample of 42 optically-selected SNRs in M33. A wide
range of [Fe II] luminosities are observed within our sample (from less than 6
to 695 L_sun). Our data suggest that the bright [Fe II] SNRs are entering the
radiative phase and that the density of the local ISM largely controls the
amount of [Fe II] emission. We derive the following relation between the [Fe
II] 1.644 microns line luminosity of radiative SNRs and the electronic density
of the postshock gas, n_e: L_[Fe II] (L_sun) ~ 1.1 n_e (cm^-3). We also find a
correlation in our data between L_[Fe II] and the metallicity of the
shock-heated gas, but the physical interpretation of this result remains
inconclusive, as our data also show a correlation between the metallicity and
n_e. The dramatically higher level of [Fe II] emission from SNRs in the central
regions of starburst galaxies is most likely due to their dense environments,
although metallicity effects might also be important. The typical [Fe
II]-emitting lifetime of a SNR in the central regions of starburst galaxies is
found to be of the order of 10^4 yr. On the basis of these results, we provide
a new empirical relation allowing the determination of the current supernova
rate of starburst galaxies from their integrated near-IR [Fe II] luminosity.Comment: 13 pages, 5 figures; accepted for publication in MNRA
Molecular gas chemistry in AGN. II. High-resolution imaging of SiO emission in NGC1068: shocks or XDR?
This paper is part of a multi-species survey of line emission from the
molecular gas in the circum-nuclear disk (CND) of the Seyfert 2 galaxy NGC1068.
Single-dish observations have provided evidence that the abundance of silicon
monoxide(SiO) in the CND of NGC1068 is enhanced by 3-4 orders of magnitude with
respect to the values typically measured in quiescent molecular gas in the
Galaxy. We aim at unveiling the mechanism(s) underlying the SiO enhancement. We
have imaged with the IRAM Plateau de Bure interferometer the emission of the
SiO(2-1) and CN(2--1) lines in NGC1068 at 150pc and 60pc spatial resolution,
respectively. We have also obtained complementary IRAM 30m observations of HNCO
and methanol (CH3OH) lines. SiO is detected in a disk of 400pc size around the
AGN. SiO abundances in the CND of (1-5)xE-09 are about 1-2 orders of magnitude
above those measured in the starburst ring. The overall abundance of CN in the
CND is high: (0.2-1)xE-07. The abundances of SiO and CN are enhanced at the
extreme velocities of gas associated with non-circular motions close to the AGN
(r<70pc). Abundances measured for CN and SiO, and the correlation of CN/CO and
SiO/CO ratios with hard X-ray irradiation, suggest that the CND of NGC1068 has
become a giant X-ray dominated region (XDR). The extreme properties of
molecular gas in the circum-nuclear molecular disk of NGC1068 result from the
interplay between different processes directly linked to nuclear activity.
Whereas XDR chemistry offers a simple explanation for CN and SiO in NGC1068,
the relevance of shocks deserves further scrutiny. The inclusion of dust grain
chemistry would help solve the controversy regarding the abundances of other
molecular species, like HCN, which are under-predicted by XDR models.Comment: 18 pages, 13 figures, 2 tables; accepted for publication in A&
Is IRAS 01072+4954 a True-Seyfert 2? Hints from Near Infrared Integral Field Spectroscopy
In contrast to the predictions of the unified model, some X-ray unobscured
Seyfert 2 galaxies have been discovered in the last decade. One of them, the
starburst/Seyfert composite galaxy IRAS 01072+4954 (z=0.0236), has a typical
Type~1 X-ray emission, while its optical spectrum resembles an HII galaxy and
lacks the expected broad lines. We performed near-infrared integral-field
observations of this object with the aim to determine the nature of its nuclear
emission and to find indications for the existence or absence of a broad-line
region. Several reasons have been proposed to explain such peculiar emission.
We studied the validity of such hypotheses, including the possibility for it to
be True-Seyfert~2. We found little obscuration towards the nucleus A_V = 2.5
mag, and a nuclear star-formation rate Sigma_SFR < 11.6 Msun yr^{-1} kpc^{-2},
which is below the average in Seyferts. Unresolved hot-dust emission with T ~
1150 K seems to indicate the presence of a torus with its axis close to the
line of sight. We found that IRAS 01072+4954 hosts a low mass black hole with
an estimated mass of M_BH ~ 10^5 Msun and an upper limit of 2.5x10^6 Msun. Its
bolometric luminosity is L_bol ~ 2.5x10^{42} erg/s, which yields a high
accretion rate with an Eddington ratio ~ 0.2. If the relations found in more
massive systems also apply to this case, then IRAS 01072+4954 should show broad
emission lines with FWHM_{broad} ~(400-600) km/s. Indeed, some indications for
such narrow broad-line components are seen in our data, but the evidence is not
yet conclusive. This source thus seems not to be a True-Seyfert 2, but an
extreme case of a narrow line Seyfert 1, which, due to the faintness of the
active nucleus, does not have strong FeII emission in the optical.Comment: 16 pages, 11 figures. A&A Accepted versio
Impaired Neurofilament Integrity and Neuronal Morphology in Different Models of Focal Cerebral Ischemia and Human Stroke Tissue
As part of the neuronal cytoskeleton, neurofilaments are involved in maintaining cellular integrity. In the setting of ischemic stroke, the affection of the neurofilament network is considered to mediate the transition towards long-lasting tissue damage. Although peripheral levels of distinct neurofilament subunits are shown to correlate with the clinically observed severity of cerebral ischemia, neurofilaments have so far not been considered for neuroprotective approaches. Therefore, the present study systematically addresses ischemia-induced alterations of the neurofilament light (NF-L), medium (NF-M), and heavy (NF-H) subunits as well as of u-internexin (INA). For this purpose, we applied a multi-parametric approach including immunofluorescence labeling, western blotting, qRT-PCR and electron microscopy. Analyses comprised ischemia-affected tissue from three stroke models of middle cerebral artery occlusion (MCAO), including approaches of filament-based MCAO in mice, thromboembolic MCAO in rats, and electrosurgical MCAO in sheep, as well as human autoptic stroke tissue. As indicated by altered immunosignals, impairment of neurofilament subunits was consistently observed throughout the applied stroke models and in human tissue. Thereby, altered NF-L immunoreactivity was also found to reach penumbral areas, while protein analysis revealed consistent reductions for NF-L and INA in the ischemia-affected neocortex in mice. At the mRNA level, the ischemic neocortex and striatum exhibited reduced expressions of NF-L- and NF-H-associated genes, whereas an upregulation for Ina appeared in the striatum. Further, multiple fluorescence labeling of neurofilament proteins revealed spheroid and bead-like structural alterations in human and rodent tissue, correlating with a cellular edema and lost cytoskeletal order at the ultrastructural level. Thus, the consistent ischemia-induced affection of neurofilament subunits in animals and human tissue, as well as the involvement of potentially salvageable tissue qualify neurofilaments as promising targets for neuroprotective strategies. During ischemia formation, such approaches may focus on the maintenance of neurofilament integrity, and appear applicable as co-treatment to modern recanalizing strategies
- …