4,744 research outputs found
Intersection of race and religion for youth in foster care: examining policy and practice
Religion and race are primary forces affecting both individuals' identities and social relations. Consequently, their impacts on child welfare systems, and the clients of the system, are important to understand. In addition to protections against discrimination on the basis of religion and race, positive affirmations and connection to relevant communities are also needed to achieve client well-being. This analysis examines both historical and contemporary approaches to addressing religion and race in child welfare policy and practice, with a particular focus on adolescent youth. Our primary focus is on Blacks and Christians because these groups have received predominant attention in the literature. We argue that because racial/ethnic and religious identity development are critical to adolescent well-being, race and religion must receive explicit and consistent attention in child welfare practice. Moreover, the importance of religion has often been overlooked, particularly in its intersection with race. Quality practice needs more explicit attention to religion, but this also raises cautions in the current political environment.Accepted manuscrip
Alien Registration- Scott, Mary E. (Saint Agatha, Aroostook County)
https://digitalmaine.com/alien_docs/33358/thumbnail.jp
Vascular remodeling of the mouse yolk sac requires hemodynamic force
The embryonic heart and vessels are dynamic and form and remodel while functional. Much has been learned about the genetic
mechanisms underlying the development of the cardiovascular system, but we are just beginning to understand how changes in
heart and vessel structure are influenced by hemodynamic forces such as shear stress. Recent work has shown that vessel
remodeling in the mouse yolk sac is secondarily effected when cardiac function is reduced or absent. These findings indicate that
proper circulation is required for vessel remodeling, but have not defined whether the role of circulation is to provide mechanical
cues, to deliver oxygen or to circulate signaling molecules. Here, we used time-lapse confocal microscopy to determine the role of
fluid-derived forces in vessel remodeling in the developing murine yolk sac. Novel methods were used to characterize flows in
normal embryos and in embryos with impaired contractility (Mlc2a^(–/–)). We found abnormal plasma and erythroblast circulation in
these embryos, which led us to hypothesize that the entry of erythroblasts into circulation is a key event in triggering vessel
remodeling. We tested this by sequestering erythroblasts in the blood islands, thereby lowering the hematocrit and reducing shear
stress, and found that vessel remodeling and the expression of eNOS (Nos3) depends on erythroblast flow. Further, we rescued
remodeling defects and eNOS expression in low-hematocrit embryos by restoring the viscosity of the blood. These data show that
hemodynamic force is necessary and sufficient to induce vessel remodeling in the mammalian yolk sa
Using Social Network Analysis on classroom video data
We propose a novel application of Social Network Analysis (SNA) using
classroom video data as a means of quantitatively and visually exploring the
collaborations between students. The context for our study was a summer program
that works with first generation students and deaf/hard-of-hearing students to
engage in authentic science practice and develop a supportive community. We
applied SNA to data from one activity during the two-week program to test our
approach and as a means to begin to assess whether the goals of the program are
being met. We used SNA to identify groups that were interacting in unexpected
ways and then to highlight how individuals were contributing to the overall
group behavior. We plan to expand our new use of SNA to video data on a larger
scale
Analysis of somitogenesis using multiphoton laser scanning microscopy (MPLSM)
In order to study complex cellular interactions in the developing somite and nervous system, we have been refining techniques for labeling and imaging individual cells within the living vertebrate embryo. Most recently, we have been using MPLSM to analyze cellular behaviors, such as cell migration, filopodial extension, cell process collapse, and neuron pathfinding using time-lapse microscopy in 3-dimensions (3-d). To enhance the efficiency of two-photon excitation in these samples, we have been using a Zeiss LSM 510 NLO fiber delivery system with a Grating Dispersion Compensator (GDC). This system not only offers the convenience of fiber delivery for coupling our Ti:Sapphire laser to the microscope, but also affords us precise control over the pulsewidth of the mode- locked beam. In addition, we have developed a novel peptide/non-cationic lipid gene delivery system to introduce GFP plasmid into somite cells. This approach has allowed us to generate detailed 3-d images of somite cell morphologies at various stages of somite development in a way that best preserves the vitality of the cells being imaged
DIRECT ESTIMATION OF ABOVEGROUND FOREST PRODUCTIVITY THROUGH HYPERSPECTRAL REMOTE SENSING OF CANOPY NITROGEN
The concentration of nitrogen in foliage has been related to rates of net photosynthesis across a wide range of plant species and functional groups and thus represents a simple and biologically meaningful link between terrestrial cycles of carbon and nitrogen. Although foliar N is used by ecosystem models to predict rates of leaf‐level photosynthesis, it has rarely been examined as a direct scalar to stand‐level carbon gain. Establishment of such relationships would greatly simplify the nature of forest C and N linkages, enhancing our ability to derive estimates of forest productivity at landscape to regional scales. Here, we report on a highly predictive relationship between whole‐canopy nitrogen concentration and aboveground forest productivity in diverse forested stands of varying age and species composition across the 360 000‐ha White Mountain National Forest, New Hampshire, USA. We also demonstrate that hyperspectral remote sensing can be used to estimate foliar N concentration, and hence forest production across a large number of contiguous images. Together these data suggest that canopy‐level N concentration is an important correlate of productivity in these forested systems, and that imaging spectrometry of canopy N can provide direct estimates of forest productivity across large landscapes
An optical coherence microscope for 3-dimensional imaging in developmental biology
An optical coherence microscope (OCM) has been designed and constructed to acquire 3-dimensional images of highly scattering biological tissue. Volume-rendering software is used to enhance 3-D visualization of the data sets. Lateral resolution of the OCM is 5 mm (FWHM), and the depth resolution is 10 mm (FWHM) in tissue. The design trade-offs for a 3-D OCM are discussed, and the fundamental photon noise limitation is measured and compared with theory. A rotating 3-D image of a frog embryo is presented to illustrate the capabilities of the instrument
Four-dimensional cardiac imaging in living embryos via postacquisition synchronization of nongated slice sequences
Being able to acquire, visualize, and analyze 3D time series
(4D data) from living embryos makes it possible to understand complex
dynamic movements at early stages of embryonic development.
Despite recent technological breakthroughs in 2D dynamic imaging,
confocal microscopes remain quite slow at capturing optical sections
at successive depths. However, when the studied motion is periodic—
such as for a beating heart—a way to circumvent this problem is to
acquire, successively, sets of 2D+time slice sequences at increasing
depths over at least one time period and later rearrange them to recover
a 3D+time sequence. In other imaging modalities at macroscopic
scales, external gating signals, e.g., an electro-cardiogram,
have been used to achieve proper synchronization. Since gating signals
are either unavailable or cumbersome to acquire in microscopic
organisms, we have developed a procedure to reconstruct volumes
based solely on the information contained in the image sequences.
The central part of the algorithm is a least-squares minimization of an
objective criterion that depends on the similarity between the data
from neighboring depths. Owing to a wavelet-based multiresolution
approach, our method is robust to common confocal microscopy artifacts.
We validate the procedure on both simulated data and in vivo
measurements from living zebrafish embryos
Dishevelled genes mediate a conserved mammalian PCP pathway to regulate convergent extension during neurulation
The planar cell polarity (PCP) pathway is conserved throughout evolution, but it mediates distinct developmental processes. In Drosophila, members of the PCP pathway localize in a polarized fashion to specify the cellular polarity within the plane of the epithelium, perpendicular to the apicobasal axis of the cell. In Xenopus and zebrafish, several homologs of the components of the fly PCP pathway control convergent extension. We have shown previously that mammalian PCP homologs regulate both cell polarity and polarized extension in the cochlea in the mouse. Here we show, using mice with null mutations in two mammalian Dishevelled homologs, Dvl1 and Dvl2, that during neurulation a homologous mammalian PCP pathway regulates concomitant lengthening and narrowing of the neural plate, a morphogenetic process defined as convergent extension. Dvl2 genetically interacts with Loop-tail, a point mutation in the mammalian PCP gene Vangl2, during neurulation. By generating Dvl2 BAC (bacterial artificial chromosome) transgenes and introducing different domain deletions and a point mutation identical to the dsh1 allele in fly, we further demonstrated a high degree of conservation between Dvl function in mammalian convergent extension and the PCP pathway in fly. In the neuroepithelium of neurulating embryos, Dvl2 shows DEP domain-dependent membrane localization, a pre-requisite for its involvement in convergent extension. Intriguing, the Loop-tail mutation that disrupts both convergent extension in the neuroepithelium and PCP in the cochlea does not disrupt Dvl2 membrane distribution in the neuroepithelium, in contrast to its drastic effect on Dvl2 localization in the cochlea. These results are discussed in light of recent models on PCP and convergent extension
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