bluuebunny/crossref_metadata_2025_split huggingface dataset:
Case‐Mix Adjusting Performance Measures in a Veteran Population: Pharmacy‐ and Diagnosis‐Based Approaches
Authors: Liu Chuan‐Fen , Sales Anne E. , Sharp Nancy D. , Fishman Paul , Sloan Kevin L. , Todd‐Stenberg Jeff , Paul Nichol W. , Rosen Amy K. , Loveland Susan 
Published: October 2003

Objective. To compare the rankings for health care utilization performance measures at the facility level in a Veterans Health Administration (VHA) health care delivery network using pharmacy‐ and diagnosis‐based case‐mix adjustment measures.Data Sources/Study Setting. The study included veterans who used inpatient or outpatient services in Veterans Integrated Service Network (VISN) 20 during fiscal year 1998 (October 1997 to September 1998; N=126,076). Utilization and pharmacy data were extracted from VHA national databases and the VISN 20 data warehouse.Study Design. We estimated concurrent regression models using pharmacy or diagnosis information in the base year (FY1998) to predict health service utilization in the same year. Utilization measures included bed days of care for inpatient care and provider visits for outpatient care.Principal Findings. Rankings of predicted utilization measures across facilities vary by case‐mix adjustment measure. There is greater consistency within the diagnosis‐based models than between the diagnosis‐ and pharmacy‐based models. The eight facilities were ranked differently by the diagnosis‐ and pharmacy‐based models.Conclusions. Choice of case‐mix adjustment measure affects rankings of facilities on performance measures, raising concerns about the validity of profiling practices. Differences in rankings may reflect differences in comparability of data capture across facilities between pharmacy and diagnosis data sources, and unstable estimates due to small numbers of patients in a facility.
Integrating R&D and Marketing: A Review and Analysis of the Literature
Authors: Griffin Abbie , Hauser John R. 
Published: October 2003

During the past 20 years, numerous studies have explored the R&D—marketing interface and its role in the new product development (NPD) process. Academics and practitioners (including a PDMA task force) have examined commonly used measures of success, the underlying reasons for the success or failure of NPD projects, and the effects of R&D—marketing integration on both project‐ and company‐level success. Does this mean we have all the answers when it comes to ensuring the necessary level of cooperation and interaction between R&D and marketing? Of course not.Abbie Griffin and John R. Hauser note that prior research on R&D—marketing integration is being reassessed in light of the movement toward flatter organizational structures and cross‐functional teams. To facilitate that reassessment, and to help guide future research in this area, they review recent research on the methods employed for integrating R&D and marketing, and they propose several hypotheses regarding those methods. They present their review and hypotheses within the framework of a causal map they have developed for studying functional integration.The causal map links cooperation to NPD success along situational dimensions, structural and process dimensions, and outcome dimensions. The desired outcome in any NPD effort is the timely commercialization of a profitable product. The situational dimensions address the amount and types of integration needed in a project, which depend on such factors as the project phase and the level of project uncertainty. The structural and process dimensions focus on the actions taken to achieve functional integration. These include relocation and physical facilities design, personnel movement, informal social systems, organizational structures, incentives and rewards, and formal integrative management processes.The proposed hypotheses focus on the methods for achieving functional integration—that is, the structural and process dimensions of the causal map. At first glance, these hypotheses seem to state the obvious. For example, few would challenge the notion that quality function deployment eliminates barriers to functional integration and improves information sharing between functions. However, achieving those benefits requires the presence of other factors such as senior management involvement. Rather than examine these hypotheses separately, researchers should explore the relative merits of the methods for achieving functional integration. In other words, future research must consider both the situational and the structural and process dimensions of this framework.
Costs and Pricing of Home Brokerage Services
Authors: Carney Michael 
Published: October 2003

This paper explores a simple economic search model, and various brokerage cost assumptions, to derive brokerage pricing implications for three dimensions of the home transaction: (1) level of home price, (2) new relative to existing home sales, and (3) co‐op relative to non‐co‐op sales. The model incorporates time‐on‐market (the price‐time tradeoff) as an important element in home brokerage (search)It is argued that relative search cost differences imply that commission rates will be lower (1) on sales of higher‐priced homes, (2) on sales of new relative to existing homes and (3) on non‐co‐op relative to co‐op sales. A main contribution of the paper is the presentation of considerable supporting evidence showing variation in actual home brokerage commission rates according to these three variables.
Home Equity Conversion Instruments with Fixed Term to Maturity: Alternatives to End of Term Pay‐Off
Authors: Weinrobe Maurice D. 
Published: October 2003

Standard reverse annuity mortgages obligate the lender to take on the risk that an elderly homeowner will desire to remain in a residence after the RAM has reached maturity. In this case, the best the lender can hope for is that the property will have appreciated sufficiently that the loan can be carried at interest only. There is a possibility for lender loss but not gain over contracted return.Alternatives to the standard RAM are explored in this paper with most attention devoted to shared appreciation and shared equity RAMs. These alternative instruments appear to solve the problem of maturity risk.
FNMA Mortgage Purchase Commitments As Put Options: An Empirical Examination
Authors: Berry Thomas D. , Gehr Adam K. 
Published: October 2003

The Federal National Mortgage Association (FNMA) auctions commitments to purchase mortgages. An examination of the terms of the commitment contract shows that these commitments are actually put options on mortgages. The contract is unusual, however, in that the price of the commitment is a fixed percentage of the value of the mortgages. In the auction, the dealers effectively bid the exercise price at which they would be willing to pay the fixed commitment price.In this paper, we study the economics of the FNMA auction. We use a two‐state approximation to the American put pricing model for interest‐dependent securities to examine the behavior of the auction results. We find that the model performs reasonably well for several years — giving results which are, on the average, correct — and then, quite abruptly, the performance of the model deteriorates. Some possible reasons for this result are then examined.
Measuring the Efficiency Cost of Rent Control
Authors: Vitaliano Donald F. 
Published: October 2003

This paper estimates the burden of lost producer surplus imposed on landlords by rent control. The approach employed measures the reduction in Marshallian quasi‐rent from the side of the derived demand for factors rather than the short‐run supply of housing.A constant elasticity of substitution production function is employed to derive the input demand equation. The equation is estimated using post‐war rent control data from five major New York State cities. It turns out that rent control reduced quasi‐rent about 15%. The deadweight loss is estimated at 1.5% of gross rental payments or about 5% of net income before debt charges.
Market Share in the Real Estate Brokerage Industry
Authors: Colwell Peter F. , Marshall David W. 
Published: October 2003

This paper is concerned with the factors that determine the market share of listings and the market share of sales for brokerage firms. Models are developed and tested in a SMSA that conveniently corresponds exactly to a particular Multiple Listing Service area. Indices of firm specialization and market concentration were computed in addition to more conventional characterizations of the market and the data used in the study.The regression results reveal a small degree of consistency in the impacts of the explanatory variables over the two years of the study and over the listing and sales markets. The number of salespeople is the most consistently significant variable. Indeed, market share per salesperson appears to be a non‐monotonic function of the number of salespeople. The presence of a franchise and the quantity of display advertising are occasionally significant. Classified advertising, Yellow Pages advertising, and open houses all do not significantly affect market share per salesperson.
The Impact of Interstate Foreclosure Cost Differences and the Value of Mortgages on Default Rates
Authors: Clauretie Terrence M. 
Published: October 2003

Previous research on mortgage default has focused on the costs, benefits, and characteristics of the mortgagor. In such studies default rates have been taken as a measure of mortgage risk. In this paper we present a model where the position of the lender affects the default‐foreclosure process. Important to the lender's decision to foreclose rather than renegotiate an existing loan are the value of mortgage and the legal costs associated with foreclosure.The empirical evidence supports the hypothesis that both the value of the mortgage and legal foreclosure costs affect the foreclosure rate. In those states where legal foreclosure costs are high rates are significantly less than where costs are low. This suggests that previous models which include only the costs and benefits of default to the borrower are incomplete and that foreclosure rates can not be taken as a strict measure of mortgage risk. That is, low foreclosure rates may indicate that losses occur in other forms of loan negotiation rather than in expensive legal costs.
Morphogenesis of
Bacillus
Spore Surfaces
Authors: Chada Venkata G. R. , Sanstad Erik A. , Wang Rong , Driks Adam 
Published: October 2003

ABSTRACT

Spores produced by bacilli are encased in a proteinaceous multilayered coat and, in some species (including
Bacillus anthracis
), further surrounded by a glycoprotein-containing exosporium. To characterize bacillus spore surface morphology and to identify proteins that direct formation of coat surface features, we used atomic-force microscopy (AFM) to image the surfaces of wild-type and mutant spores of
Bacillus subtilis
, as well as the spore surfaces of
Bacillus cereus
569 and the Sterne strain of
Bacillus anthracis
. This analysis revealed that the coat surfaces in these strains are populated by a series of bumps ranging between 7 and 40 nm in diameter, depending on the species. Furthermore, a series of ridges encircled the spore, most of which were oriented along the long axis of the spore. The structures of these ridges differ sufficiently between species to permit species-specific identification. We propose that ridges are formed early in spore formation, when the spore volume likely decreases, and that when the spore swells during germination the ridges unfold. AFM analysis of a set of
B. subtilis
coat protein gene mutants revealed three coat proteins with roles in coat surface morphology: CotA, CotB, and CotE. Our data indicate novel roles for CotA and CotB in ridge pattern formation. Taken together, these results are consistent with the view that the coat is not inert. Rather, the coat is a dynamic structure that accommodates changes in spore volume.
Requirement of theListeria monocytogenesBroad-Range Phospholipase PC-PLC during Infection of Human Epithelial Cells
Authors: Gründling Angelika , Gonzalez Mark D. , Higgins Darren E. 
Published: October 2003

ABSTRACTIn this study, we investigated the requirement of theListeria monocytogenesbroad-range phospholipase C (PC-PLC) during infection of human epithelial cells.L. monocytogenesis a facultative intracellular bacterial pathogen of humans and a variety of animal species. After entering a host cell,L. monocytogenesis initially surrounded by a membrane-bound vacuole. Bacteria promote their escape from this vacuole, grow within the host cell cytosol, and spread from cell to cell via actin-based motility. Most infection studies withL. monocytogeneshave been performed with mouse cells or an in vivo mouse model of infection. In all mouse-derived cells tested, the pore-forming cytolysin listeriolysin O (LLO) is absolutely required for lysis of primary vacuoles formed during host cell entry. However,L. monocytogenescan escape from primary vacuoles in the absence of LLO during infection of human epithelial cell lines Henle 407, HEp-2, and HeLa. Previous studies have shown that the broad-range phospholipase C, PC-PLC, promotes lysis of Henle 407 cell primary vacuoles in the absence of LLO. Here, we have shown that PC-PLC is also required for lysis of HEp-2 and HeLa cell primary vacuoles in the absence of LLO expression. Furthermore, our results indicated that the amount of PC-PLC activity is critical for the efficiency of vacuolar lysis. In an LLO-negative derivative ofL. monocytogenesstrain 10403S, expression of PC-PLC has to increase before or upon entry into human epithelial cells, compared to expression in broth culture, to allow bacterial escape from primary vacuoles. Using a system for inducible PC-PLC expression inL. monocytogenes, we provide evidence that phospholipase activity can be increased by elevated expression of PC-PLC or Mpl, the enzyme required for proteolytic activation of PC-PLC. Lastly, by using the inducible PC-PLC expression system, we demonstrate that, in the absence of LLO, PC-PLC activity is not only required for lysis of primary vacuoles in human epithelial cells but is also necessary for efficient cell-to-cell spread. We speculate that the additional requirement for PC-PLC activity is for lysis of secondary double-membrane vacuoles formed during cell-to-cell spread.
A Mutant of
Paracoccus denitrificans
with Disrupted Genes Coding for Cytochrome
c
550
and Pseudoazurin Establishes These Two Proteins as the In Vivo Electron Donors to Cytochrome
cd
1
Nitrite Reductase
Authors: Pearson Isobel V. , Page M. Dudley , van Spanning Rob J. M. , Ferguson Stuart J. 
Published: October 2003

ABSTRACT

In
Paracoccus denitrificans
, electrons pass from the membrane-bound cytochrome
bc
1
complex to the periplasmic nitrite reductase, cytochrome
cd
1
. The periplasmic protein cytochrome
c
550
has often been implicated in this electron transfer, but its absence, as a consequence of mutation, has previously been shown to result in almost no attenuation in the ability of the nitrite reductase to function in intact cells. Here, the hypothesis that cytochrome
c
550
and pseudoazurin are alternative electron carriers from the cytochrome
bc
1
complex to the nitrite reductase was tested by construction of mutants of
P. denitrificans
that are deficient in either pseudoazurin or both pseudoazurin and cytochrome
c
550
. The latter organism, but not the former (which is almost indistinguishable in this respect from the wild type), grows poorly under anaerobic conditions with nitrate as an added electron acceptor and accumulates nitrite in the medium. Growth under aerobic conditions with either succinate or methanol as the carbon source is not significantly affected in mutants lacking either pseudoazurin or cytochrome
c
550
or both these proteins. We concluded that pseudoazurin and cytochrome
c
550
are the alternative electron mediator proteins between the cytochrome
bc
1
complex and the cytochrome
cd
1
-type nitrite reductase. We also concluded that expression of pseudoazurin is mainly controlled by the transcriptional activator FnrP.
Increasing the Ratio of Soj to Spo0J Promotes Replication Initiation inBacillus subtilis
Authors: Ogura Yoshitoshi , Ogasawara Naotake , Harry Elizabeth J. , Moriya Shigeki 
Published: October 2003

ABSTRACTThe ParA and ParB protein families are well conserved in bacteria. However, their functions are still unclear. InBacillus subtilis, Soj and Spo0J are members of these two protein families, respectively. A previous report revealed that replication initiated early and asynchronously inspo0Jnull mutant cells, as determined by flow cytometry. In this study, we examined the cause of this promotion of replication initiation. Deletion of both thesojandspo0Jgenes restored the frequency of replication initiation to almost the wild-type level, suggesting that production of Soj in the absence of Spo0J leads to early and asynchronous initiation of replication. Consistent with this suggestion, overproduction of Soj in wild-type cells had the same effect on replication initiation as in thespo0Jnull mutant, and overproduction of both Soj and Spo0J did not. These results indicate that when the ratio of Soj to Spo0J increases, Soj interferes with tight control of replication initiation and causes early and asynchronous initiation. Whereas replication initiation also occurred significantly earlier in the twospo0Jmutants,spo0J14andspo0J17, it occurred only slightly early in thesojK16Qmutant and was delayed in thesojG12Vmutant. Although Soj localized to nucleoids in thespo0Jmutants, the two Soj mutant proteins were distributed throughout the cell or localized to cell poles. Thus, interestingly, the promotion of replication initiation seems to correlate with localization of Soj to nucleoids. This may suggest that Soj inhibits transcription of some cell cycle genes and leads to early and asynchronous initiation of replication. In wild-type cells Spo0J counteracts this Soj function.
Biochemical Properties and Regulated Gene Expression of the Superoxide Dismutase from the Facultatively Aerobic Hyperthermophile
Pyrobaculum calidifontis
Authors: Amo Taku , Atomi Haruyuki , Imanaka Tadayuki 
Published: October 2003

ABSTRACT

Superoxide dismutase (SOD) was purified from a facultatively aerobic hyperthermophilic archaeon,
Pyrobaculum calidifontis
VA1. The purified native protein from aerobically grown cells exhibited 1,960 U of SOD activity/mg and contained 0.86 ± 0.04 manganese and <0.01 iron atoms per subunit. The gene encoding SOD was cloned and expressed in
Escherichia coli
. Although the recombinant protein was soluble, little activity was observed due to the lack of metal incorporation. Reconstitution of the enzyme by heat treatment with either Mn or Fe yielded a highly active protein with specific activities of 1,970 and 434 U/mg, respectively. This indicated that the SOD from
P. calidifontis
was a cambialistic SOD with a preference toward Mn in terms of activity. Interestingly, reconstitution experiments in vitro indicated a higher tendency of the enzyme to incorporate Fe than Mn. When
P. calidifontis
was grown under anaerobic conditions, a majority of the native SOD was incorporated with Fe, indicating the cambialistic property of this enzyme in vivo. We further examined the expression levels of SOD and a previously characterized Mn catalase from this strain in the presence or absence of oxygen. Northern blot, Western blot, and activity measurement analyses revealed that both genes are expressed at much higher levels under aerobic conditions. We also detected a rapid response in the biosynthesis of these enzymes once the cells were exposed to oxygen.
Genome-Wide Transcriptional Profiling Analysis of Adaptation ofBacillus subtilisto High Salinity
Authors: Steil Leif , Hoffmann Tamara , Budde Ina , Völker Uwe , Bremer Erhard 
Published: October 2003

ABSTRACTThe gram-positive soil bacteriumBacillus subtilisoften faces increases in the salinity in its natural habitats. A transcriptional profiling approach was utilized to investigate both the initial reaction to a sudden increase in salinity elicited by the addition of 0.4 M NaCl and the cellular adaptation reactions to prolonged growth at high salinity (1.2 M NaCl). Following salt shock, asigBmutant displayed immediate and transient induction and repression of 75 and 51 genes, respectively. Continuous propagation of this strain in the presence of 1.2 M NaCl triggered the induction of 123 genes and led to the repression of 101 genes. In summary, our studies revealed (i) an immediate and transient induction of the SigW regulon following salt shock, (ii) a role of the DegS/DegU two-component system in sensing high salinity, (iii) a high-salinity-mediated iron limitation, and (iv) a repression of chemotaxis and motility genes by high salinity, causing severe impairment of the swarming capability ofB. subtiliscells. Initial adaptation to salt shock and continuous growth at high salinity share only a limited set of induced and repressed genes. This finding strongly suggests that these two phases of adaptation require distinctively different physiological adaptation reactions by theB. subtiliscell. The large portion of genes with unassigned functions among the high-salinity-induced or -repressed genes demonstrates that major aspects of the cellular adaptation ofB. subtilisto high salinity are unexplored so far.
Genome-Scale Analysis of the Uses of the
Escherichia coli
Genome: Model-Driven Analysis of Heterogeneous Data Sets
Authors: Allen Timothy E. , Herrgård Markus J. , Liu Mingzhu , Qiu Yu , Glasner Jeremy D. , Blattner Frederick R. , Palsson Bernhard Ø. 
Published: October 2003

ABSTRACT

The recent availability of heterogeneous high-throughput data types has increased the need for scalable in silico methods with which to integrate data related to the processes of regulation, protein synthesis, and metabolism. A sequence-based framework for modeling transcription and translation in prokaryotes has been established and has been extended to study the expression state of the entire
Escherichia coli
genome. The resulting in silico analysis of the expression state highlighted three facets of gene expression in
E. coli
: (i) the metabolic resources required for genome expression and protein synthesis were found to be relatively invariant under the conditions tested; (ii) effective promoter strengths were estimated at the genome scale by using global mRNA abundance and half-life data, revealing genes subject to regulation under the experimental conditions tested; and (iii) large-scale genome location-dependent expression patterns with approximately 600-kb periodicity were detected in the
E. coli
genome based on the 49 expression data sets analyzed. These results support the notion that a structured model-driven analysis of expression data yields additional information that can be subjected to commonly used statistical analyses. The integration of heterogeneous genome-scale data (i.e., sequence, expression data, and mRNA half-life data) is readily achieved in the context of an in silico model.