Structuring Joint Action Routines: A Strategy for Facilitating Communication and Language Development in the Classroom

The study of early child language has produced a wealth of new data and con­comitant theories over the past decade, and these new perspectives offer important im­plications to those of us engaged in clinical practice. We have noted elsewhere that this current literature on early child language has specific implications for designing ap­propriate targets, contexts, and procedures for language therapy (McLean and Snyder-­McLean, 1978; McLean, Snyder-McLean, and Sack, 1983). In this article, we will con­centrate on these two latter areas: contexts and procedures for language intervention and, more specifically, on the combination of these elements in the form of structured joint action routines

A novel amniote model of epimorphic regeneration: the leopard gecko, Eublepharis macularius

<p>Abstract</p> <p>Background</p> <p>Epimorphic regeneration results in the restoration of lost tissues and structures from an aggregation of proliferating cells known as a blastema. Among amniotes the most striking example of epimorphic regeneration comes from tail regenerating lizards. Although tail regeneration is often studied in the context of ecological costs and benefits, details of the sequence of tissue-level events are lacking. Here we investigate the anatomical and histological events that characterize tail regeneration in the leopard gecko, <it>Eublepharis macularius</it>.</p> <p>Results</p> <p>Tail structure and tissue composition were examined at multiple days following tail loss, revealing a conserved pattern of regeneration. Removal of the tail results in a consistent series of morphological and histological events. Tail loss is followed by a latent period of wound healing with no visible signs of regenerative outgrowth. During this latent period basal cells of the epidermis proliferate and gradually cover the wound. An additional aggregation of proliferating cells accumulates adjacent to the distal tip of the severed spinal cord marking the first appearance of the blastema. Continued growth of the blastema is matched by the initiation of angiogenesis, followed by the re-development of peripheral axons and the ependymal tube of the spinal cord. Skeletal tissue differentiation, corresponding with the expression of Sox9, and muscle re-development are delayed until tail outgrowth is well underway.</p> <p>Conclusions</p> <p>We demonstrate that tail regeneration in lizards involves a highly conserved sequence of events permitting the establishment of a staging table. We show that tail loss is followed by a latent period of scar-free healing of the wound site, and that regeneration is blastema-mediated. We conclude that the major events of epimorphic regeneration are highly conserved across vertebrates and that a comparative approach is an invaluable biomedical tool for ongoing regenerative research.</p

1-1.4 Micron Spectral Atlas of Stars

We present a catalog of J-band (1.08 um to 1.35 um) stellar spectra at low resolution (R ~ 400). The targets consist of 105 stars ranging in spectral type from O9.5 to M7 and luminosity classes I through V. The relatively featureless spectra of hot stars, earlier than A4, can be used to remove the atmospheric features which dominate ground-based J-band spectroscopy. We measure equivalent widths for three absorption lines and nine blended features which we identify in the spectra. Using detailed comparison with higher resolution spectra, we demonstrate that low resolution data can be used for stellar classification, since several features depend on the effective temperature and gravity. For example The CN index (1.096 - 1.104 um) decreases with temperature, but the strength of a blended feature at 1.28 um (consisting of primarily P beta) increases. The slope of a star's spectrum can also be used to estimate its effective temperature. The luminosity class of a star correlates with the ratio of the Mg I (1.1831 um) line to a blend of several species at 1.16 um. Using these indicators, a star can be classified to within several subclasses. Fifteen stars with particularly high and low metal abundances are included in the catalog and some spectral dependence on metal abundance is also found.Comment: 35 pages, 10 figures (3a-e are in gif format. For complete high resolution figures, go to http://www.astro.ucla.edu/~malkan/newjspec/) ; Accepted for published in ApJS; For associated spectra files, see http://www.astro.ucla.edu/~malkan/newjspec

Hot Stars and Cool Clouds: The Photodissociation Region M16

We present high-resolution spectroscopy and images of a photodissociation region (PDR) in M16 obtained during commissioning of NIRSPEC on the Keck II telescope. PDRs play a significant role in regulating star formation, and M16 offers the opportunity to examine the physical processes of a PDR in detail. We simultaneously observe both the molecular and ionized phases of the PDR and resolve the spatial and kinematic differences between them. The most prominent regions of the PDR are viewed edge-on. Fluorescent emission from nearby stars is the primary excitation source, although collisions also preferentially populate the lowest vibrational levels of H2. Variations in density-sensitive emission line ratios demonstrate that the molecular cloud is clumpy, with an average density n = 3x10^5 cm^(-3). We measure the kinetic temperature of the molecular region directly and find T_H2 = 930 K. The observed density, temperature, and UV flux imply a photoelectric heating efficiency of 4%. In the ionized region, n_i=5x10^3 cm^(-3) and T_HII = 9500 K. In the brightest regions of the PDR, the recombination line widths include a non-thermal component, which we attribute to viewing geometry.Comment: 5 pages including 2 Postscript figures. To appear in ApJ Letters, April 200

K-Band Spectroscopy of an Obscured Massive Stellar Cluster in the Antennae Galaxies (NGC 4038/4039) with NIRSPEC

We present infrared spectroscopy of the Antennae Galaxies (NGC 4038/4039) with NIRSPEC at the W. M. Keck Observatory. We imaged the star clusters in the vicinity of the southern nucleus (NGC 4039) in 0.39" seeing in K-band using NIRSPEC's slit-viewing camera. The brightest star cluster revealed in the near-IR (M_K(0) = -17.9) is insignificant optically, but coincident with the highest surface brightness peak in the mid-IR (12-18 um) ISO image presented by Mirabel et al (1998). We obtained high signal-to-noise 2.03-2.45 um spectra of the nucleus and the obscured star cluster at R = 1900. The cluster is very young (age ~ 4 Myr), massive (M ~ 16E6 M_sun), and compact (density ~ 115 M_sun pc^(-3) within a 32 pc half-light radius), assuming a Salpeter IMF (0.1-100 M_sun). Its hot stars have a radiation field characterized by T_eff ~ 39,000 K, and they ionize a compact HII region with n_e ~ 10^4 cm^(-3). The stars are deeply embedded in gas and dust (A_V = 9-10 mag), and their strong FUV field powers a clumpy photodissociation region with densities n_H > 10^5 cm^(-3) on scales of ~ 200 pc, radiating L{H_2 1-0 S(1)}= 9600 L_sun.Comment: 4 pages, 4 embedded figures, uses emulateapj.sty. To appear in ApJL. Also available at http://astro.berkeley.edu/~agilber

Influence of pore-scale disorder on viscous fingering during drainage

We study viscous fingering during drainage experiments in linear Hele-Shaw cells filled with a random porous medium. The central zone of the cell is found to be statistically more occupied than the average, and to have a lateral width of 40% of the system width, irrespectively of the capillary number $Ca$. A crossover length $w_f \propto Ca^{-1}$ separates lower scales where the invader's fractal dimension $D\simeq1.83$ is identical to capillary fingering, and larger scales where the dimension is found to be $D\simeq1.53$. The lateral width and the large scale dimension are lower than the results for Diffusion Limited Aggregation, but can be explained in terms of Dielectric Breakdown Model. Indeed, we show that when averaging over the quenched disorder in capillary thresholds, an effective law $v\propto (\nabla P)^2$ relates the average interface growth rate and the local pressure gradient.Comment: 4 pages, 4 figures, submitted to Phys Rev Letter

ISTRAŽIVANJE MOGUĆNOSTI RASTA KOMARČI DRŽANIH U KOMERCIJALNOM RECIRKULACIJSKOM SISTEMU I TRETIRANIH NUSPROIZVODOM INDUSTRIJSKE PROIZVODNJE GOVEĐEG HORMONA RASTA

Gilthead sea bream, maintained in a commercial scale recirculation system, were subjected to three injections (0,5 and 10 µg -1 body weight) with a by-product from the industrial production of recombinant bovine growth hormone (rbGH). Injections were provided at experiment start and at 3 and 6 weeks. Growth performance of animals was evaluated over a period of 8 weeks (n = 171 per treatment). At trial end fish were examined for proximate composition, fillet yield and visceral indices. No differences were recorded in individual growth performance between the three treatment groups (P > 0.05). Examination of protein productive value and protein efficiency ratio indicated approximately 20% of dietary protein was incorporated into animals irrespective of treatment. However incorporation of dietary lipid decreased with increasing dose of rbGH. High dose GH decreased liver weight (P 0,05). Istraživanje vrijednosti produktivnog proteina i količine efikasnosti proteina pokazalo je da je približno 20% proteina bilo inkorporirano u životinje neovisno o tretmanu. No inkorporacija lipida bila je smanjena povećanjem doze hormona rasta (rbGH). Visoka doza hormona rasta smanjila je težinu jetre (P < 0,05) u usporedbi s kontrolom s istodobnim smanjenjem hepatosomatskog indeksa (P < 0,05). Težina i postotak fileta bili su viši u životinja tretiranih dozom od 10 µg g -1 tjelesne težine u usporedbi s niskom dozom rbGH tretiranih riba (P < 0,05)

ISTRAŽIVANJE MOGUĆNOSTI RASTA KOMARČI DRŽANIH U KOMERCIJALNOM RECIRKULACIJSKOM SISTEMU I TRETIRANIH NUSPROIZVODOM INDUSTRIJSKE PROIZVODNJE GOVEĐEG HORMONA RASTA

Gilthead sea bream, maintained in a commercial scale recirculation system, were subjected to three injections (0,5 and 10 µg -1 body weight) with a by-product from the industrial production of recombinant bovine growth hormone (rbGH). Injections were provided at experiment start and at 3 and 6 weeks. Growth performance of animals was evaluated over a period of 8 weeks (n = 171 per treatment). At trial end fish were examined for proximate composition, fillet yield and visceral indices. No differences were recorded in individual growth performance between the three treatment groups (P > 0.05). Examination of protein productive value and protein efficiency ratio indicated approximately 20% of dietary protein was incorporated into animals irrespective of treatment. However incorporation of dietary lipid decreased with increasing dose of rbGH. High dose GH decreased liver weight (P 0,05). Istraživanje vrijednosti produktivnog proteina i količine efikasnosti proteina pokazalo je da je približno 20% proteina bilo inkorporirano u životinje neovisno o tretmanu. No inkorporacija lipida bila je smanjena povećanjem doze hormona rasta (rbGH). Visoka doza hormona rasta smanjila je težinu jetre (P < 0,05) u usporedbi s kontrolom s istodobnim smanjenjem hepatosomatskog indeksa (P < 0,05). Težina i postotak fileta bili su viši u životinja tretiranih dozom od 10 µg g -1 tjelesne težine u usporedbi s niskom dozom rbGH tretiranih riba (P < 0,05)