471 research outputs found

    Aggregation Bias in Price Indices for Multi-Family Rental Properties

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    This article examines aggregation bias in price index construction. Specifically, we test whether changes in values of 2- to 4-unit, multi-family rental housing properties vary systematically in the same market across property size. Moreover, we examine the time trend differences across locations within a geographic region for various sized multiplex properties, as well as investigate how size should be measured. Results suggest that absolute price changes are significantly different across property size, as determined by living area, and that the time trend does not differ across locations within a geographic region. Further research using this methodology is recommended for other property types.

    The Effects of Subdivision Design on Housing Values: The Case of Alleyways

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    Subdivision design likely impacts residential housing values. This study examines the sale prices of houses located in subdivisions utilizing rear-entry alleyways in the Greater Dallas-Fort Worth-Denton metroplex. Regression analysis on a sample of 1,672 home sales, some of which are located on alleyways, reveals statistically significant impacts. Consequently, developers, appraisers, New Urbanists and other real estate participants should consider subdivision design when estimating value for residential dwellings.

    Creating a Constant-Quality Index for Small Multifamily Rental Housing

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    Researchers since the early 1960s have constructed constant-quality price indices (CQIs) for single-family dwellings. This paper, however, applies the methodology to construct CQIs for a different property type - small multifamily rental housing with two to four units (MRH) - so that price changes can be measured. Over the period 1983 through 1988, MRH prices increased 70% in Connecticut, but decreased nearly 65% in Baton Rouge, Louisiana. These locations and the sample period are chosen because Connecticut's economy boomed, while Baton Rouge's collapsed; as well, Congress debated and passsed the 1986 Tax Reform Act (TR). TRA affected both regions' MRH prices, but other factors contributed to price changes, also.

    An Empirical Investigation of Federal Wetlands Regulation and Flood Delineation: Implications for Residential Property Owners

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    Since the early 1970s, the federal government has undertaken extensive efforts to stem the loss of wetlands by regulating the use of land. This paper investigates the extent to which residential property owners are affected by federal wetlands regulation, by presenting an empirical investigation of such economic consequences. Results suggest that because of the Supreme Court?s holding in United States v. Riverside Bayview Homes, Inc., sale prices of properties located in a wetlands area were discounted nearly eight percent, even after controlling for some sample properties being flood delineated.

    Contagion and REIT Stock Prices

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    This article investigates the contagious movement of real estate investment trust (REIT) stock prices in response to real estate news related to financial institutions' real estate portfolios. The basic hypothesis is that because real estate assets are traded infrequently, the market has incomplete information about their true value; thus, REIT stock prices react negatively to announcements of poorly performing real estate portfolios of financial institutions. Consistent with the hypothesis, significantly negative reactions to these announcements are found for a portfolio of sixty-nine REITs during the real estate crisis of 1989--91.

    A Heuristic Neural Network Structure Relying on Fuzzy Logic for Images Scoring

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    Traditional deep learning methods are sub-optimal in classifying ambiguity features, which often arise in noisy and hard to predict categories, especially, to distinguish semantic scoring. Semantic scoring, depending on semantic logic to implement evaluation, inevitably contains fuzzy description and misses some concepts, for example, the ambiguous relationship between normal and probably normal always presents unclear boundaries (normal − more likely normal - probably normal). Thus, human error is common when annotating images. Differing from existing methods that focus on modifying kernel structure of neural networks, this study proposes a dominant fuzzy fully connected layer (FFCL) for Breast Imaging Reporting and Data System (BI-RADS) scoring and validates the universality of this proposed structure. This proposed model aims to develop complementary properties of scoring for semantic paradigms, while constructing fuzzy rules based on analyzing human thought patterns, and to particularly reduce the influence of semantic conglutination. Specifically, this semantic-sensitive defuzzier layer projects features occupied by relative categories into semantic space, and a fuzzy decoder modifies probabilities of the last output layer referring to the global trend. Moreover, the ambiguous semantic space between two relative categories shrinks during the learning phases, as the positive and negative growth trends of one category appearing among its relatives were considered. We first used the Euclidean Distance (ED) to zoom in the distance between the real scores and the predicted scores, and then employed two sample t test method to evidence the advantage of the FFCL architecture. Extensive experimental results performed on the CBIS-DDSM dataset show that our FFCL structure can achieve superior performances for both triple and multiclass classification in BI-RADS scoring, outperforming the state-of-the-art methods

    The impact of narrative storytelling on cognitive re-composition in individuals struggling with eating disorders.

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    Externalization is the separation of the person from the problem. This narrative based research used a mixed method research design conducted with 16 participants. Participants engaged in writing stories from an externalized perspective of the eating disorder. Relevant themes emerged from the externalized writing process. Themes included: self concept, family/social relationships, eating disorder character, allies to eating disorder, deification of eating disorder, sexuality, inner strength, and voice of eating disorder. Although quantitative analysis did not yield significant results, qualitative findings yielded information that may facilitate understanding and psychological treatment of persons struggling with eating disorders

    Detection of HER2 amplification in circulating free DNA in patients with breast cancer.

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    BACKGROUND: Human epidermal growth factor receptor 2 (HER2) is amplified and overexpressed in 20-25% of breast cancers. This study investigated circulating free DNA (cfDNA) for detection of HER2 gene amplification in patients with breast cancer. METHODS: Circulating free DNA was extracted from plasma of unselected patients with primary breast cancer (22 before surgery and 68 following treatment), 30 metastatic patients and 98 female controls using the QIAamp Blood DNA Mini Kit (Qiagen). The ratio of HER2 to an unamplified reference gene (contactin-associated protein 1 (CNTNAP1)) was measured in cfDNA samples by quantitative PCR (qPCR) using SK-BR-3 cell line DNA as a positive control. RESULTS: We validated the qPCR assay with DNA extracted from 23 HER2 3+ and 40 HER2-negative tumour tissue samples; the results agreed for 60 of 63 (95.2%) tumours. Amplification was detected in cfDNA for 8 of 68 patients following primary breast cancer treatment and 5 of 30 metastatic patients, but was undetected in 22 patients with primary breast cancer and 98 healthy female controls. Of the patients with amplification in cfDNA, 10 had HER2 3+ tumour status by immunohistochemistry. CONCLUSIONS: The results demonstrate for the first time the existence of amplified HER2 in cfDNA in the follow-up of breast cancer patients who are otherwise disease free. This approach could potentially provide a marker in patients with HER2-positive breast cancer

    Influence of plasma processing on recovery and analysis of circulating nucleic acids.

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    Circulating nucleic acids (CNAs) are under investigation as a liquid biopsy in cancer. However there is wide variation in blood processing and methods for isolation of circulating free DNA (cfDNA) and microRNAs (miRNAs). Here we compare the extraction efficiency and reproducibility of 4 commercially available kits for cfDNA and 3 for miRNA using spike-in of reference templates. We also compare the effects of increasing time between venepuncture and centrifugation and differential centrifugation force on recovery of CNAs. cfDNA was quantified by TaqMan qPCR and targeted deep sequencing. miRNA profiles were assessed with TaqMan low-density arrays and assays. The QIAamp(®) DNA Blood Mini and Circulating nucleic acid kits gave the highest recovery of cfDNA and efficient recovery (>90%) of a 564bp spike-in. Moreover, targeted sequencing revealed overlapping cfDNA profiles and variant depth, including detection of HER2 gene amplification, using the Ion AmpliSeq™Cancer Hotspot Panel v2. Highest yields of miRNA and the synthetic Arabidopsis thaliana miR-159a spike-in were obtained using the miRNeasy Serum/Plasma kit, with saturation above 200 µl of plasma. miRNA profiles showed significant variation with increasing time before centrifugation (p 12 years, highlighting the potential for analysis of stored sample biobanks. In the era of the liquid biopsy, standardisation of methods is required to minimise variation, particularly for miRNA

    Plasmodium P-Type Cyclin CYC3 Modulates Endomitotic Growth during Oocyst Development in Mosquitoes

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    Cell-cycle progression and cell division in eukaryotes are governed in part by the cyclin family and their regulation of cyclin-dependent kinases (CDKs). Cyclins are very well characterised in model systems such as yeast and human cells, but surprisingly little is known about their number and role in Plasmodium, the unicellular protozoan parasite that causes malaria. Malaria parasite cell division and proliferation differs from that of many eukaryotes. During its life cycle it undergoes two types of mitosis: endomitosis in asexual stages and an extremely rapid mitotic process during male gametogenesis. Both schizogony (producing merozoites) in host liver and red blood cells, and sporogony (producing sporozoites) in the mosquito vector, are endomitotic with repeated nuclear replication, without chromosome condensation, before cell division. The role of specific cyclins during Plasmodium cell proliferation was unknown. We show here that the Plasmodium genome contains only three cyclin genes, representing an unusual repertoire of cyclin classes. Expression and reverse genetic analyses of the single Plant (P)-type cyclin, CYC3, in the rodent malaria parasite, Plasmodium berghei, revealed a cytoplasmic and nuclear location of the GFP-tagged protein throughout the lifecycle. Deletion of cyc3 resulted in defects in size, number and growth of oocysts, with abnormalities in budding and sporozoite formation. Furthermore, global transcript analysis of the cyc3-deleted and wild type parasites at gametocyte and ookinete stages identified differentially expressed genes required for signalling, invasion and oocyst development. Collectively these data suggest that cyc3 modulates oocyst endomitotic development in Plasmodium berghei
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