As the U.S. Department of Housing and Urban Development (HUD) shifts its emphasis from project-based subsidies to housing
vouchers, a key question is the amount of relocation help that should be provided to voucher recipients. To address these
and related issues, this article examines the use of and influence of relocation counseling at four distressed federally subsidized
housing developments (in Baltimore, Maryland; Newport News, Virginia; Kansas City, Missouri; and San Francisco, California)
where families were provided with vouchers and relocation counseling in order to expedite moves into the private housing market.
Both qualitative and quantitative analysis techniques were used to examine the different approaches to relocation counseling
provided by four types of providers: 1) community-based non-profit housing agencies; 2) a private company and its subcontractor,
an out-of-town consultant specializing in relocation counseling; 3) a state housing agency; and 4) the on-site housing management
company.
Underutilization of relocation counseling was a problem: only two-fifths of the sample reported using relocation services.
Middle-aged tenants and those at the Baltimore site were most likely to take advantage of the services; those living in overcrowded
units were least likely. Programs need to be developed to increase participation rates while recognizing that tenant involvement
must remain voluntary in nature at such sites. Although there was some evidence that the more intensive relocation counseling
provided in Newport News opened up more housing options for residents, in general the counseling had limited impact. Those
who used relocation counseling did not consider more housing options than others, nor were they more likely to focus their
housing search on distant neighborhoods. Furthermore, residents depended on friends and relatives, rather than relocation
counselors, to learn about their new home.
Even though many respondents made short-distance moves (especially in Baltimore and Kansas City), they usually were able to
improve their housing and neighborhood conditions. These findings suggest that it may be unreasonable to expect families-particularly
those relying on public transportation—to relocate to new and unfamiliar neighborhoods without support, or without intensive
counseling, encouraging them to do so. Spatial deconcentration may not always be an appropriate goal for all voucher recipients.
David P. Varady co-principal investigator, Professor of Planning is Professor of Planning at the University of Cincinnati. Professor Varady
has written widely about community conservation and housing policy, both in the United States and the United Kingdom. His
most recent book, co-edited with Wolfgang F.E. Preiser and Francis P. Russell,New Directions in Urban Public Housing, was published by the Center for Urban Policy Research, Fall, 1988.
Carole C. Walker co-principal investigator, is Assistant Director of the Center for Urban Policy Research at Rutgers University. In her years
at the Center, she has studied a broad range of public policy issues, including program evaluation, affordable housing,subdivision
regulations, and land use development. She is the author of numerous research studies and co-author with David Listokin ofThe Subdivision and Site Plan Handbook.
Kirk McClure investigator, is an Associate Professor with the Graduate Program in Urban Planning at the University of Kansas. His teaching
and research interests are in the areas of housing and community development. He has recently completed research evaluating
the ten-year performance of the Low-Income Housing Tax Credit program and is now engaged in an examination of the secondary
mortgage market as an aid to affordable housing.
Janet Smith-Heimer, investigator, is the founding principal of Bay Area Economics (BAE), a national consulting firm specializing in urban and
real estate economics. She has been actively engaged in urban development since 1978 and has developed expertise in affordable
housing, economic development, and military base closure.
Sherry Larkins research assistant, is a Ph.D. candidate in sociology at Rutgers University. Her areas of interest are race relations, urban
sociology, and substance abuse. 相似文献
Mechanically milled FeCrNbB feedstock powders from commercial precursors were used to produce amorphous coatings through two different industrial thermal-spraying techniques: high-velocity oxygen fuel (HVOF) and flame spraying. Microstructure, thermal behavior, and hardness of the coatings and their corrosion resistances in acidic and alkaline chloride-rich media were comparatively studied. HVOF process was effective to produce ~ 200-µm-thick highly amorphous coatings with hardness over than 700 HV0.3 and low porosity (~ 5 pct). Flame-sprayed ~ 220-µm-thick coatings were nanocrystalline, composed of α-Fe, Fe2B, FeNbB, and Fe2O3 phases and presented hardness of 564 HV0.3 and ~ 10 pct porosity. Electrochemical measurements indicated that HVOF coatings exhibit higher corrosion resistance than flame-sprayed ones thanks to the higher amorphous content and lower porosity resulting from the former processing route. Electrochemical impedance spectroscopy results demonstrated that amorphous HVOF Fe60Cr8Nb8B24 (at. pct) coatings are interesting to protect mild steels such as the API 5L X80 against corrosion in chloride-rich environments.
The two-wave-plate compensator (TWC) method is expanded for full-field retardation measurements by use of a polarization microscope. The sample image is projected onto a CCD camera connected to a computer, allowing the retardation to be measured at all pixels. The retardation accuracy of this implementation of the TWC is evaluated to be 0.06 nm. The method is applied to polarization-maintaining fibers and long-period fiber gratings. The measured retardation is in good agreement with the crossed-polarizer images of the fibers. The method achieves a spatial resolution of 0.45 microm and a retardation resolution of 0.07 nm. The full-field TWC method can thus be a useful tool for characterizing and monitoring the fabrication of optical devices. 相似文献
We present the characterizations performed at the Institut Fresnel for the Measurement Problem of the Optical Interference Coatings 2004 Topical Meeting. A single layer coated on a fused-silica substrate of unknown composition and parameters is analyzed in terms of optogeometrical parameters, uniformity, and scattering. We determine the refractive index and the average thickness of the coating, then provide the localized determination of the thickness with a 2 mm spatial resolution. Topography measurements include atomic force microscopy and angle-resolved scattering measurements. These results are completed thanks to a Taylor Hobson noncontact 3D surface profiler. 相似文献
Specular ellipsometry is a well-known and efficient technique to characterize surfaces and coatings. This technique has been extended to the measurement of scattered light. We present an experimental setup, using a polarization modulator, which permits us to characterize transition layers and roughness without a calibration procedure. Experimental results are presented concerning transition layers for damage threshold applications and for rough surfaces or bulks. 相似文献
In the present study a synthetic glycolipid system is presented that can be readily incorporated into phospholipid micelles and that allows the study of cell-surface-exposed carbohydrate units by high-resolution NMR techniques. Here, we present an efficient route for the synthesis of glycolipid compounds that contain mannose, mannobiose, or mannotriose coupled either directly to an alkyl chain or through a poly(ethylene glycol) linker. Furthermore, we have validated our model system by measuring the binding of cyanovirin N (CV-N), a cyanobacterial protein that binds with nanomolar affinity to the terminal arms of high-mannose structures of the HIV surface-envelope glycoprotein gp120, to glycolipids the carbohydrate portions of which comprise the corresponding high-mannose moieties. From the results of chemical-shift mapping with uniformly (15)N-labelled CV-N, we conclude that binding to the protein occurs at sites similar to those involved in binding the nonconjugated carbohydrates. We characterized the insertion of the glycolipids into dodecylphosphocholine (DPC) micelles by measuring translational diffusion, and we observed that the diffusion constants of the glycolipids were very similar to those of the DPC micelles themselves, but significantly deviated from those of the free glycolipids. We also present experimental proof that the glycolipids remain inserted in the micelles while binding to CV-N. Finally, by addition of a ligand that had a higher affinity to CV-N but which was not attached did not couple to a lipid anchor, CV-N could be released from the glycolipid and, hence, from the micelle-associated state. 相似文献
Recently, cancer stem cells (CSCs) have been identified in many types of cancers, such as colorectal cancer (CRC). CSCs seem to be involved in initiation, growth, and tumor metastasis, as well as in radio- and chemotherapy failures. CSCs appears as new biological targets for cancer therapy, requiring the development of noninvasive cell sorting methods. In this study, we used sedimentation field flow fractionation (SdFFF) to prepare enriched populations of CSCs from eight cell lines corresponding to different CRC grades. On the basis of phenotypic and functional characterizations, "hyperlayer" elution resulted in a fraction overexpressing CSC markers (CD44, CD166, EpCAM) for all cell lines. CSCs were eluted in the last fraction for seven out of eight cell lines, but in the first for HCT116. These results suggest, according to the literature, that two different pools of CSCs exist, quiescent and activated, which can both be sorted by SdFFF. Moreover, according to CSC properties, enriched fractions are able to form colonies. 相似文献
Under anaerobic conditions, such as those typically found in buried sediments, the primary metabolic pathway for polychlorinated biphenyls (PCBs) is reductive dechlorination in which chlorine removal and substitution with hydrogen by bacteria result in a reduced organic compound with fewer chlorines. Vertical sediment cores were collected from Lake Hartwell (Pickens County, SC) and analyzed in 5-cm intervals for 107 PCB congeners in a total of more than 280 samples from 18 sediment cores and surface samples. This paper reports on extensive PCB dechlorination measured in Lake Hartwell sediments and the characterization of dechlorination end-member (EM) patterns using chemical forensic methods. PCB congener fingerprinting and a multivariate receptor modeling method, polytopic vector analysis (PVA), were used for identification and characterization of weathered and dechlorinated PCB congener patterns. Dechlorination resulted in a substantial shift in buried sediments from tetra- through decachlorobiphenyl congeners to mono- through trichlorobiphenyl congeners. Mono- through trichlorobiphenyls comprised approximately 80% of the PCBs in buried sediments that underwent maximum dechlorination as compared to approximately 20% in surface sediments. The major concentration decreases were seen in the tetra- through hexachlorobiphenyl homologues, which accounted for over 90% of the dechlorination. Octa- through decachlorobiphenyl congeners also were dechlorinated, but their overall contribution to dechlorination was relatively small due to their low initial concentrations (< 5%). The net accumulation of 2-CB, 2,2'/2,6-DCBs, 2,4'-DCB, 2,2',4-TCB, and 2,2',6-TCB at Lake Hartwell matched characteristic PCB dechlorination products reported in the literature, such as those for Processes M, Q, and C; and the persistence of tetrachlorobiphenyls (TeCBs) that contained 24- and 25-congener groups resembled dechlorination Processes H or H'. Although dechlorination tended to be very extensive in most of the cores, it was not always consistent from core to core or at various depth intervals within a single core. The reason for this variability in dechlorination extent could not be determined from the existing data and did not appear to correlate with such factors as PCB concentration, total organic carbon, or age. The authors used fingerprinting analysis and a PVA multivariate receptor model as exploratory data analysis tools to characterize PCB sources and their alteration patterns. Dominant sources and alteration patterns were determined in this large data set by comparing PVA EM patterns with known source patterns (i.e., Aroclors or Aroclor mixtures) and literature-reported alteration patterns. PVA also afforded an opportunity to characterize the vertical and lateral distributions of the weathered and unweathered PCB source patterns and dechlorination patterns, a task that would have been much more difficult to accomplish through comparison of chromatograms alone. 相似文献