Application of the semivariogram textural classifier (STC) for vegetation discrimination using SIR-B data of Borneo

Abstract

Classification of Shuttle Imaging Radar-B (SIR-B) data from a rainforest-covered portion of Borneo is performed using image texture. The algorithm used is the semivariogram textural classifier (STC). This is a deterministic, supervised parallelepiped type classifier which provides the option of combining textural and radiometric information. Textural information is expressed by the semivariogram function. Radiometric information is conveyed by the mean digital number (DN) value. Results of the classificaiion cmulale a previously published map obtained by visual interpretation of the same SIR-B data set.     

“GOOD” NEIGHBORHOODS IN PORTLAND,OREGON: FOCUS ON BOTH SOCIAL AND PHYSICAL ENVIRONMENTS

ABSTRACT: We conduct an empirical investigation of the social environment of “good” neighborhoods in physical form in a model of the “compact city,” Portland, Oregon and discuss the implications for design and evaluation of policies inspired by smart growth and new urbanist movements that focus on the urban form and transportation dimensions of neighborhoods, and of housing assistance policies designed to change the economic mix in neighborhoods. We conceptualize the physical and social dimensions of the “good” neighborhood environment and develop an approach to operationalization that uses publicly available data. Our findings indicate that for the most part, Portland has been successful in creating neighborhoods at several economic scales that feature not only the connectivity, accessibility, mixed land use, and access to public transit that characterize “good” neighborhoods from a physical perspective, but also a “good” social environment indicative of strong ties and collective efficacy. However, there are signs that in the process, Portland may be creating poverty areas that lack connectivity, accessibility, and access to public transit and a mix of destinations.     

Effect of Frozen Storage on the Gel-forming Properties of Hoki (Macruronus novaezelandiae)

The possibility of using frozen hoki to make surimi was investigated. At intervals, fish were thawed under controlled conditions and gels were then made from minces of the flesh. Both puncture and torsion tests showed the quality of gels declined with duration of storage of frozen hoki. This decline was matched by a decrease in pH and an increase in formaldehyde concentration in the frozen flesh. The data suggest a land-based surimi plant could not be operated outside the harvesting season to any appreciable extent using frozen hoki stored at -29°C.     

POTENTIAL FOR BACTERIAL GROWTH ON THE FRESH CUT TROPICAL SQUASH, CALABAZA (CURCUBITA MOSCHATA), DURING STORAGE

Calabaza (Curcubita moschata) is a tropical squash which is gaining popularity as a specialty crop for agricultural producers in the Northeast United States. It is commonly marketed by being cut in half, wrapped in plastic and may be held unrefrigerated until sold. This method of display is essential for consumer acceptance, yet unrefrigerated storage means that some potential for food safety problems exists. Experiments were conducted to determine the potential for bacterial growth during storage of cut calabaza. Freshly cut calabaza contained between 1.3 and 4.7 log₁₀CFU/g aerobic mesophiles. By 10 h, duplicate counts from some samples exceeded 4 log₁₀ CFU/g. After 24 h of room temperature storage, total aerobic plate counts ranged from 5.2 to 7.7 log₁₀ CFU/g. Rapid bacterial growth on cut calabaza stored at room temperature indicates that these products are highly perishable, and may be able to support the growth of pathogenic bacteria, should they be introduced during the slicing process.     

Effect of Water and Serum Absorption on Wear of Unirradiated and Crosslinked UHMWPE Orthopedic Bearing Materials

Abstract

In addition to confounding mass-based wear measurements in serum-lubricated hip simulator experiments, fluid absorption by the acetabular cups may simultaneously modify the wear resistance of the ultra-high molecular weight polyethylene (UHMWPE) from which they are composed. To decouple the fluid absorption and wear processes enabling clearer investigation of this effect, absorption was first imposed during an initial stage where UHMWPE was exposed to pressurized (10 MPa) fluid. This was followed by a second stage, where resultant wear behavior was assessed by a multidirectional pin-on-flat technique that, though still providing a serum-lubricating environment, does not promote the simultaneous fluid absorption occurring in hip simulator testing. Both unirradiated and highly crosslinked UHMWPE were investigated, each with both bovine calf serum and water soaking exposures of duration to 129 days. The pressurized soaking of a highly crosslinked UHMWPE decreased its wear resistance, causing an increase in wear rate by approximately 50% during subsequent serum-lubricated multidirectional pin-on-flat sliding tests as compared to non-soaked material. The magnitude of this effect did not appear to depend on whether the soaking fluid was water or serum, nor did it appear to depend on soak time provided it was at least of a 14-day duration, during which more rapid transient fluid absorption occurs. Such soaking did not produce as pronounced an effect on unirradiated UHMWPE, as its lack of wear resistance likely causes the absorption-affected surface region to be removed within the earliest stages of sliding contact.     

Strength of Gels Prepared from Washed and Unwashed Minces of Hoki (Macruronus novaezelandiae) Stored in Ice

Washed and unwashed fish minces were prepared from hoki that had been stored in ice. Gels were formed from the minces, cooked at both 60°C and 90°C and assessed by puncture, torsion and a folding test method. The strength of the gels decreased as the fish were stored. However, after 10 days, the strength of gels made from hoki minces still compared favorably with gels made from other commercial fish species without storage. This suggests that manufacture of hoki surimi on-shore may be practical. Fish freshness as evaluated by sensory methods was closely related to the K value and gel strength. Hence K values might provide the basis of a raw material quality control system for an on-shore surimi plant.     

The Evolution of Integrative Capability: Innovation in Cardiovascular Drug Discovery

Recent research has highlighted the ability to integrate fragmentedknowledge across boundaries within a firm as a potentially potentsource of competitive advantage. Yet this research raises apotent tally puzzling question: if these capabilities are socentral to competitive advantage, why do they not instantaneouslydiffuse across an industry? This paper draws on a detailed fieldstudy of the development of hypertensive drugs in 10 major Europeanand American firms to explore this issue. I suggest that anyparticular integrative competence rests on a complex set ofinterlinked factors that usually evolve only slowly over time.Those firms that were fortunate enough to have focused earlyon more 'rational' modes of drug discovery have been much moresuccesssful in developing the integrative capabilities fundamentalto modern drug discovery than those that initially achievedgreat success with the more traditional 'random' method of drugdiscovery. The results thus speak directly to evolutionary theoriesof competence development. They also raise intriguing questionsabout the relationship between the development of competenceand the larger institutional context of the industry, since- both the wealth and prominence of public sector biomedicalresearch and the use of mechanism of action as an integrativedevice appear to have shaped the formation of capability inthe industry.     

LOW‐INCOME HOMEOWNERSHIP: DOES IT NECESSARILY MEAN SACRIFICING NEIGHBORHOOD QUALITY TO BUY A HOME?

ABSTRACT: Questions have been raised about the wisdom of low‐income homeownership policies for many reasons. One potential reason to be skeptical: low‐income homebuyers perhaps may be constrained to purchase homes in disadvantaged neighborhoods. This is a potential problem because home purchases in such neighborhoods: (1) may limit appreciation; (2) may reduce quality of life for adults; and (3) may militate against reputed advantages of homeownership for children. Our study examines the neighborhood conditions of a group of 126 low‐income homebuyers who purchased their first home with assistance from the Home Ownership Program (HOP) operated by the Denver Housing Authority. Our approach is distinguished by its use of a comprehensive set of objective and subjective indicators measuring the neighborhood quality of pre‐move and post‐move neighborhoods. Do low‐income homebuyers sacrifice neighborhood quality to buy their homes? Our results suggest that the answer to this question is more complex than it might at first appear. On the one hand, HOP homebuyers purchased in a wide variety of city and suburban neighborhoods. Nonetheless, a variety of neighborhood quality indicators suggest that these neighborhoods, on average, were indeed inferior to those of Denver homeowners overall and to those in the same ethnic group. However, our analyses also revealed that their post‐move neighborhoods were superior to the ones they lived in prior to homeownership. Moreover, very few HOP destination neighborhoods evinced severe physical, environmental, infrastructural, or socioeconomic problems, as measured by a wide variety of objective indicators or by the homebuyers' own perceptions. Indeed, only 10% of HOP homebuyers perceived that their new neighborhoods were worse than their prior ones, and only 8% held pessimistic expectations about their new neighborhoods' quality of life. Finally, we found that Black homebuyers fared less well than their Latino counterparts, on average, in both objective and subjective measures.     

SUBURBAN DEVELOPMENT AND ECONOMIC SEGREGATION IN THE 1990s

ABSTRACT: Suburbanization is changing the face of urban America. A common claim is that suburban sprawl has contributed to increasing levels of economic segregation, but few studies have directly tested this hypothesis. Using U.S. Census data for 1990 and 2000, this paper examines the trends in and the relationship between suburban development patterns and economic segregation in U.S. metropolitan areas. We find that economic segregation, as measured by the Neighborhood Sorting Index (NSI), declined during the 1990s, reversing the earlier trend. However, results from cross‐sectional and fixed‐effects regression models at the metropolitan level suggest that suburbanization, as measured by five different indicators, was a countervailing influence during the decade. Metropolitan areas that were suburbanizing more rapidly had smaller declines in economic segregation than comparable metropolitan areas.