bluuebunny/crossref_metadata_2025 huggingface dataset:
Review of methodologies and a protocol for the Agrobacterium-mediated transformation of wheat
Authors: Jones Huw D , Doherty Angela , Wu Huixia
Published: September 2005

Since the first report of wheat transformation by Agrobacterium tumefaciens in 1997, various factors that influence T-DNA delivery and regeneration in tissue culture have been further investigated and modified. This paper reviews the current methodology literature describing Agrobacterium transformation of wheat and provides a complete protocol that we have developed and used to produce over one hundred transgenic lines in both spring and winter wheat varieties.
Absence of autoantibodies against correctly folded recombinant fibrillin-1 protein in systemic sclerosis patients
Authors: Brinckmann Jürgen , Hunzelmann Nico , El-Hallous Ehab , Krieg Thomas , Sakai Lynn Y , Krengel Sven , Reinhardt Dieter P
Published: September 2005

Autoantibodies against short recombinant fragments of fibrillin-1 produced in bacterial expression systems have been found in tight-skin mouse, systemic sclerosis, mixed connective tissue disease, and primary pulmonary hypertension syndrome. In patients with scleroderma, the frequency of anti-fibrillin-1 antibodies was 42% in Caucasians. Until now it has been unclear whether this immune response has a primary function in disease pathogenesis or is a secondary phenomenon. In the present study we analyzed the frequency of autoantibodies against two overlapping recombinant polypeptides spanning the N-terminal and C-terminal halves of human fibrillin-1, which were produced in human embryonic kidney (HEK-293) cells. Correct three-dimensional structures of the recombinant fibrillin-1 polypeptides were shown by electron microscopy and immunoreactivity with antibodies. Screening of fibrillin-1 antibodies was performed in 41 sera from systemic sclerosis patients and in 44 healthy controls with a Caucasian background. Microtiter plates were coated with the recombinant polypeptides of fibrillin-1 and incubated with 1:100 diluted sera. Positive binding was defined as being more than 2 SD above the mean of the control group. ELISAs showed that none of the sera of patients with systemic sclerosis contained autoantibodies against the N-terminal or C-terminal recombinant fibrillin-1 polypeptide. The data show the absence of autoantibodies against recombinant fibrillin-1 protein in Caucasian systemic sclerosis patients. Because the correct three-dimensional folding of the recombinant proteins has been substantiated by several independent methods, we conclude that autoantibodies against correctly folded fibrillin are not a primary phenomenon in the pathogenesis of systemic sclerosis.
Optimizing the Supply Chain Configuration for New Products
Authors: Graves Stephen C. , Willems Sean P.
Published: September 2005

We address how to configure the supply chain for a new product for which the design has already been decided. The central question is to determine what suppliers, parts, processes, and transportation modes to select at each stage in the supply chain. There might be multiple options to supply a raw material, to manufacture or assemble the product, and to transport the product to the customer. Each of these options is differentiated by its lead time and direct cost added. Given these various choices along the supply chain, the configuration problem is to select the options that minimize the total supply chain cost. We develop a dynamic program with two state variables to solve the supply chain configuration problem for supply chains that are modeled as spanning trees. We illustrate the problem and its solution with an industrial example. We use the example to show the benefit from optimization relative to heuristics and to form hypotheses concerning the structure of optimal supply chain configurations. We conduct a computational experiment to test these hypotheses.
The Making of a “Hot Product”: A Signaling Explanation of Marketers’ Scarcity Strategy
Authors: Stock Axel , Balachander Subramanian
Published: September 2005

Every marketer’s dream is to create a “hot product” that customers would absolutely want to have, thus generating considerable profit to the marketer. According to one school of thought, marketers should make products hard to get in order to create really hot products. In this paper, using a game-theoretic model, we investigate if such scarcity strategies can indeed be optimal. While a scarcity strategy may appear to be a viable approach for making a firm’s product successful, further analysis raises some puzzling issues. In particular, it is not clear why a firm would not increase its price to get demand and supply in sync and increase its profit in the process. We therefore offer a signaling explanation for the optimality of such strategies and show that a high-quality seller may optimally choose to make the product scarce in order to credibly signal the quality of its product to uninformed customers. Our analysis indicates that a high-quality seller optimally employs scarcity as a signaling device in product markets that are characterized, ceteris paribus, by a small difference in marginal cost between high- and low-quality products, a low reservation price for a low-quality product, a greater heterogeneity in reservation prices for a high-quality product, and a moderate number of informed consumers. Our results provide a rationale for the fact that scarcity strategies are usually observed for discretionary or specialty products, but not for commodity products, staple products, or new-to-the-world products.
Inventory Management for an Assembly System with Product or Component Returns
Authors: DeCroix Gregory A. , Zipkin Paul H.
Published: September 2005

This paper considers an inventory system with an assembly structure. In addition to uncertain customer demands, the system experiences uncertain returns from customers. Some of the components in the returned products can be recovered and reused, and these units are returned to inventory. Returns complicate the structure of the system, so that the standard approach (based on reduction to an equivalent series system) no longer applies in general. We identify conditions on the item-recovery pattern and restrictions on the inventory policy under which an equivalent series system does exist. For the special case where only the end product (or all items used to assemble the end product) is recovered, we show that the system is equivalent to a series system with no policy restrictions. For the general case, we explain how and why the system becomes more problematic and propose two heuristic policies. The heuristics are easy to compute and practical to implement, and they perform well in numerical trials. Based on these numerical trials, we obtain insights into the impact of various factors on system performance. For example, we find that holding and backorder costs tend to increase when the average return rate, the variability of returns, or the number of components recovered increases. However, neither the product architecture nor the specific set of components being recovered seems to have a significant impact on these costs. Whether product recovery reduces total system costs depends on the magnitude of the additional holding and backorder costs relative to potential procurement cost savings.
Quality Implications of Warranties in a Supply Chain
Authors: Balachandran Kashi R. , Radhakrishnan Suresh
Published: September 2005

We examine a supply chain in which the final product consists of components made by a buyer and a supplier. In the single moral-hazard case, the buyer’s quality is observable, whereas in the double moral-hazard case, the buyer’s quality is not observable. The supplier’s quality is not observable in both the single and double moral-hazard cases. In each case, we examine a warranty/penalty contract between the buyer and the supplier based on information from incoming inspection and external failures. When the warranty contract is based on information from external failures in the single moral-hazard case, the first-best quality is achieved, whereas in the double moral-hazard case, the first-best quality is achieved if the supplier is not held responsible for the buyer’s defects. When the warranty contract is based on information from incoming inspection, the first-best is achieved in both the single and double moral-hazard cases, even when the incoming inspection does not identify all of the supplier’s defectives. An analysis of whether the penalty on the supplier in each case meets a fairness criterion—that is, the penalty does not exceed the manufacturer’s external failure cost—indicates that the fairness criterion is met by the warranty contract based on information from incoming inspection when the first-best incoming inspection is sufficiently high. However, if the first-best incoming inspection is low and the precision of pinpointing the supplier’s responsibility for external failure is sufficiently high, the warranty contract based on external failures could satisfy the fairness criterion.
Entry by Spinoffs
Authors: Klepper Steven , Sleeper Sally
Published: September 2005

Entry by spinoffs from incumbent firms is investigated for the laser industry. A model in which spinoffs exploit knowledge from their parents is constructed to explain the market conditions conducive to spinoffs, the types of firms that spawn spinoffs, and the relationship of spinoffs to their parents. The model is tested using detailed data on all laser entrants from the start of the industry through 1994. Our findings support the basic premise of the model that spinoffs inherit knowledge from their parents that shapes their nature at birth. Implications of our findings for organizational behavior, business strategy, entry and industry evolution, and technological change are discussed.
Selling and Leasing Strategies for Durable Goods with Complementary Products
Authors: Bhaskaran Sreekumar R. , Gilbert Stephen M.
Published: September 2005

It has been recognized that when a durable goods manufacturer sells its output, it has an incentive to produce at a rate that will drive down the market price of the product over time. Because anticipation of declining prices makes consumers less willing to invest in owning the durable good, selling can be self-defeating for the manufacturer. If the manufacturer instead leases the product, it can eliminate its own incentive to decrease the price over time, which allows it to extract larger rents from consumers. In this paper, we investigate how a durable goods manufacturer’s choice between leasing and selling is affected by a complementary product that is produced by an independent firm. We show that a durable goods manufacturer that leases its product has an incentive to increase prices (by limiting the availability of the product) in response to the availability of a complement. Because this potential for opportunistic behavior discourages output of the complement, leasing can also be problematic. As a result, the durable goods manufacturer faces a trade-off between leasing, which commits the manufacturer to not overproduce, and selling, which commits it to not underproduce. Our contribution is to identify this trade-off and show how a durable goods manufacturer can use a combination of leasing and selling to balance its strategic commitment across both its own market as well as the complementary market.
Allocating Spending Between Advertising and Information Technology in Electronic Retailing
Authors: Tan Yong , Mookerjee Vijay S.
Published: September 2005

This study examines coordination issues that occur in allocating spending between advertising and information technology (IT) in electronic retailing. Electronic retailers run the risk of overspending on advertising to attract customers but underspending on IT, thus resulting in inadequate processing capacity at the firm’s website. In this paper, we present a centralized, joint marketing-IT model to optimally allocate spending between advertising and IT, and we discuss an uncoordinated case where marketing and IT make suboptimal advertising and capacity decisions. We show how these decisions can be coordinated either by reducing the value of a customer session or by designing an optimal processing contract between marketing and IT. Both the coordination methods can be implemented with only local knowledge of the IT function, yet they generate a solution that almost matches the quality of the centralized solution. We extend our basic model to consider demand uncertainty, lagged advertising effects, and uncertainties in the lead time to acquire IT capacity. With demand uncertainty, electronic retailers should reduce spending on advertising and increase IT capacity if there is potential for a demand upswing and the cost of IT capacity is relatively low. The value of a customer session should be further reduced when uncertainties exist. This is required to share the risk of excess or inadequate IT capacity.
A Theoretical Approach to Web Design in E-Commerce: A Belief Reinforcement Model
Authors: Song Jaeki , Zahedi Fatemeh “Mariam”
Published: September 2005

Effective website design plays a critical role in attracting and maintaining customers’ interest. Despite the importance of websites as the major and, at times, sole channel of communication in e-business, little theoretical knowledge is available about how websites may influence online shoppers’ attitudes and behavior. In this paper, we develop a conceptual framework for measuring the impact of Web-design elements on the beliefs and behavior of Web customers. In developing the theoretical model (called the belief reinforcement model, or BRM), we synthesize the theory of planned behavior with theories in social psychology, consumer behavior, and management to categorize Web-design elements and conceptualize the salient aspects of Web shoppers’ behavior. The empirical examination of BRM indicates that various categories of Web-design elements reinforce Web customers’ beliefs, which in turn positively impact attitudinal constructs that lead to changes in their purchase intentions. BRM and its results provide an initial guideline for a rigorous approach to designing websites for e-business and testing their effectiveness before their full deployment.
Conceptual Bases of Christian, Faith-Based Substance Abuse Rehabilitation Programs
Authors: McCoy Lisa K. , Hermos John A. , Bokhourm Barbara G. , Frayne Susan M.
Published: September 2005

Faith-based substance abuse rehabilitation programs provide residential treatment for many substance abusers. To determine key governing concepts of such programs, we conducted semi-structured interviews with sample of eleven clinical and administrative staff referred to us by program directors at six, Evangelical Christian, faith-based, residential rehabilitation programs representing two large, nationwide networks. Qualitative analysis using grounded theory methods examined how spirituality is incorporated into treatment and elicited key theories of addiction and recovery. Although containing comprehensive secular components, the core activities are strongly rooted in a Christian belief system that informs their understanding of addiction and recovery and drives the treatment format. These governing conceptions, that addiction stems from attempts to fill a spiritual void through substance use and recovery through salvation and a long-term relationship with God, provide an explicit, theory-driven model upon which they base their core treatment activities. Knowledge of these core concepts and practices should be helpful to clinicians in considering referrals to faith-based recovery programs.
Risk/Protective Factors Associated with Substance Use among Runaway/Homeless Youth Utilizing Emergency Shelter Services Nationwide
Authors: Thompson Sanna J.
Published: September 2005

Rates of alcohol, tobacco, and marijuana use among runaway/homeless youth are substantially higher than found among American high school students. To understand the risk and protective factors associated with substance use, this study (1) assessed cigarette, alcohol, and marijuana use among a national sample of runaway/homeless youth, (2) identified risk/protective factors associated with lifetime substance use, and (3) examined risk/protective factors associated with six month frequency of substance use. Unduplicated cases (n = 11,841) from the 1997 Runaway/Homeless Youth Management Information System (RHY MIS) were analyzed. Results showed that substance use levels are greater than previously reported for this population. Predictors of cigarette, alcohol, and marijuana use and frequency were predominately individual youth risk factors and demographics rather than family risk factors. Providers in emergency youth shelters are in a prime position to assess substance use behaviors, as well as the associated risk factors. Provision of appropriate screening and referral to other services is essential to meet the needs of these youth.
Advanced experimental techniques in polymer thermodynamics
Authors: Grolier Jean-Pierre E.
Published: September 2005

Scanning transitiometry is at the center of several new developments to generate original unprecedented data over extended ranges of temperatures and pressures. Simultaneous in situ spectroscopic readings noticeably extend the performance of scanning transitiometry. The modulation of temperature superimposed to temperature scanning for thermal analysis is a major step forward to unambiguously identify glass transitions from other overlapping phenomena. The combination of a weighing technique (vibrating-wire technique) with a pressure decay technique (pVT technique) allows us to estimate simultaneously, in situ on the same polymer sample, the gas solubility and the concomitant polymer swelling.
The fascinating world of pure and mixed nonelectrolytes
Authors: Wilhelm Emmerich
Published: September 2005

In the first part of this work, the focus is on the molar heat capacity CV
at constant volume of fairly simple liquids. This quantity contains valuable information on the type of motion executed by the constituent molecules. Using the residual property formalism, the (hindered) rotational behavior of quasi-rigid molecules in the dense liquid phase will be discussed. To this end, the change of CV
determined for states along the saturation curve has to be resolved into the separated changes with temperature and volume, respectively. In the second part, the focus is on binary liquid mixtures containing one strongly polar component. Polar interactions constitute an important example of orientational forces between molecules, and substantial deviations of the properties of polar fluids from those of comparable nonpolar fluids are to be expected and indeed observed. At sufficiently low temperatures, these directional forces lead to significantly increased local structure. Extension of these ideas to liquid mixtures allows a semi-quantitative discussion of W-shaped excess molar heat capacities Cp

E at constant pressure and M-shaped excess molar enthalpies H
E.
Computer modeling in materials chemistry
Authors: Catlow C. R. A.
Published: September 2005

This short article concerns the application of computer modeling techniques to the growing field of materials chemistry, where modeling techniques are widely used in an increasingly predictive manner. The article focuses on modeling at the atomic and molecular level.
From colloidal dispersions to colloidal pastes through solid-liquid separation processes
Authors: Madeline J. B. , Meireles M. , Persello J. , Martin C. , Botet R. , Schweins R. , Cabane B.
Published: September 2005

Solid-liquid separation is an operation that starts with a dispersion of solid particles in a liquid and removes some of the liquid from the particles, producing a concentrated solid paste and a clean liquid phase. It is similar to thermodynamic processes where pressure is applied to a system in order to reduce its volume. In dispersions, the resistance to this osmotic compression depends on interactions between the dispersed particles.

The first part of this work deals with dispersions of repelling particles, which are either silica nanoparticles or synthetic clay platelets, dispersed in aqueous solutions. In these conditions, each particle is surrounded by an ionic layer, which repels other ionic layers. This results in a structure with strong short-range order. At high particle volume fractions, the overlap of ionic layers generates large osmotic pressures; these pressures may be calculated, through the cell model, as the cost of reducing the volume of each cell. The variation of osmotic pressure with volume fraction is the equation of state of the dispersion.

The second part of this work deals with dispersions of aggregated particles, which are silica nanoparticles, dispersed in water and flocculated by multivalent cations. This produces large bushy aggregates, with fractal structures that are maintained through interparticle surface-surface bonds. As the paste is submitted to osmotic pressures, small relative displacements of the aggregated particles lead to structural collapse. The final structure is made of a dense skeleton immersed in a nearly homogeneous matrix of aggregated particles. The variation of osmotic resistance with volume fraction is the compression law of the paste; it may be calculated through a numerical model that takes into account the noncentral interparticle forces. According to this model, the response of aggregated pastes to applied stress may be controlled through the manipulation of interparticle adhesion.
Control of spiral instabilities in reaction-diffusion systems
Authors: Liao Hui-Min , Jiang Min-Xi , Wang Xiao-Nan , Zhou Lu-Qun , Ouyang Qi
Published: September 2005

Spiral instabilities and their controls are investigated in a reaction-diffusion system using the Belousov-Zhabotinsky reaction. Two spiral instabilities, the long-wavelength instability and the Doppler instability, are reported, which can lead to spatiotemporal chaos. The long-wavelength instability occurs in an oscillatory regime, while the Doppler instability occurs in an excitable regime. To control these two instabilities, two different strategies are proposed according to their defect-generating mechanisms. For the long-wavelength instability in an oscillatory system, the control can be achieved by introducing a local pacemaker, which emits stable traveling waves to sweep off the unstable spiral defects. For the Doppler instability, the control can be achieved by trapping the spiral tip with a local area of higher diffusion coefficient than its surroundings.
Critical evaluation of stability constants of metal complexes of complexones for biomedical and environmental applications* (IUPAC Technical Report)
Authors: Anderegg Giorgio , Arnaud-Neu Francoise , Delgado Rita , Felcman Judith , Popov Konstantin
Published: September 2005

Available experimental data on stability constants of proton (hydron) and metal complexes for seven complexones of particular biomedical and environmental interest: iminodiacetic acid [2,2'-azanediyldiacetic acid, IDA], (methylimino)diacetic acid [2,2'-(methylazanediyl)diacetic acid, MIDA]; 2,2',2'',2'''-{[(carboxymethyl)azanediyl]bis[(ethane-1,2-diyl)nitrilo]}tetraacetic acid (DTPA), 3,6,9,12-tetrakis(carboxymethyl)-3,6,9,12-tetraazatetradecanedioic acid (TTHA); 2,2',2''-(1,4,7-triazonane-1,4,7-triyl)triacetic acid (NOTA); 2,2',2'',2'''-(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrayl)tetraacetic acid (DOTA); 2,2',2'',2'''-(1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetrayl)tetraacetic acid (TETA), published in 1945-2000, have been critically evaluated. Some typical errors in stability constant measurements for particular complexones are summarized. Higher quality data are selected and presented as “Recommended” or “Provisional”.
Chronic Wasting Disease
Authors: Williams E. S.
Published: September 2005

Chronic wasting disease (CWD) is a unique transmissible spongiform encephalopathy (TSE) of mule deer ( Odocoileus hemionus), white-tailed deer ( O. virginianus), and Rocky Mountain elk ( Cervus elaphus nelsoni). The natural history of CWD is incompletely understood, but it differs from scrapie and bovine spongiform encephalopathy (BSE) by virtue of its occurrence in nondomestic and free-ranging species. CWD has many features in common with scrapie, including early widespread distribution of disease-associated prion protein (PrPd) in lymphoid tissues, with later involvement of central nervous system (CNS) and peripheral tissues. This distribution likely contributes to apparent efficiency of horizontal transmission and, in this, is similar to scrapie and differs from BSE. Clinical features and lesions of CWD are qualitatively similar to the other animal TSEs. Microscopically, marked spongiform lesions occur in the central nervous system (CNS) after a prolonged incubation period and variable course of clinical disease. During incubation, PrPd can be identified in tissues by antibody-based detection systems. Although CWD can be transmitted by intracerebral inoculation to cattle, sheep, and goats, ongoing studies have not demonstrated that domestic livestock are susceptible via oral exposure, the presumed natural route of exposure to TSEs. Surveillance efforts for CWD in captive and free-ranging cervids will continue in concert with similar activities for scrapie and BSE. Eradication of CWD in farmed cervids is the goal of state, federal, and industry programs, but eradication of CWD from free-ranging populations of cervids is unlikely with currently available management techniques.
Microarray Analysis of Differentially Expressed Genes of Primary Tumors in the Canine Central Nervous System
Authors: Thomson S. A. M. , Kennerly E. , Olby N. , Mickelson J. R. , Hoffmann D. E. , Dickinson P. J. , Gibson G. , Breen M.
Published: September 2005

The pathophysiologic similarities of many human and canine cancers support the role of the domestic dog as a model for brain tumor research. Here we report the construction of a custom canine brain-specific cDNA microarray and the analysis of gene expression patterns of several different types of canine brain tumor The microarray contained 4000 clones from a canine brain specific cDNA library including 2161 clones that matched known genes or expressed sequence tags (ESTs) and 25 cancer-related genes. Our study included 16 brain tumors (seven meningiomas, five glial tumors, two ependymomas, and two choroid plexus papillomas) from a variety of different dog breeds. We identified several genes previously found to be differentially expressed in human brain tumors. This suggests that human and canine brain tumors share a common pathogenesis. In addition, we also found differentially expressed genes unique to either meningiomas or the glial tumors. This report represents the first global gene expression analysis of different types of canine brain tumors by cDNA microarrays and might aid in the identification of potential candidate genes involved in tumor formation and progression.
Ultrastructural Changes of the Tracheal Epithelium after Vaccination of Day-Old Chickens with the La Sota Strain of Newcastle Disease Virus
Authors: Mast J. , Nanbru C. , van den Berg T. , Meulemans G.
Published: September 2005

The progression of tracheal lesions induced by vaccination of day-old specific pathogen-free chicks with the La Sota strain of Newcastle disease virus (NDV) was examined by relating surface changes as observed by scanning electron microscopy with subcellular changes seen by transmission electron microscopy. NDV infection resulted in hypertrophy of goblet cells, their rupture, and the formation of excess mucus. Activation of goblet cells peaked within 4 days postvaccination. Afterward, the activation levels gradually decreased. At the level of the ciliated cells, a marked increase in the proportion of nonciliated to ciliated cells and later an almost complete deciliation of the tracheal surface were observed because a simple squamous to cuboidal epithelium replaced the original pseudostratified epithelium. Fifteen days postvaccination, all epithelial damage was restored. Because the observed vaccination-induced lesions are detrimental to epithelial integrity and function as a barrier against invading microorganisms, they might explain at the ultrastructural level the secondary complications of vaccination with the La Sota strain against NDV
Locoweed (Oxytropis sericea)—induced Lesions in Mule Deer (Odocoileius hemionus)
Authors: Stegelmeier B. L. , James L. F. , Gardner D. R. , Panter K. E. , Lee S. T. , Ralphs M. H. , Pfister J. A. , Spraker T. R.
Published: September 2005

Locoweed poisoning has been reported in wildlife, but it is unknown whether mule deer ( Odocoileius hemionus)are susceptible. In areas that are heavily infested with locoweed, deer and elk ( Cervus elaphus nelsoni)have developed a spongiform encephalopathy, chronic wasting disease (CWD). Although these are distinct diseases, no good comparisons are available. The purpose of this study was to induce and describe chronic locoweed poisoning in deer and compare it with the lesions of CWD. Two groups of four mule deer were fed either a complete pelleted ration or a similar ration containing 15% locoweed ( Oxytropis sericea). Poisoned deer lost weight and developed a scruffy, dull coat. They developed reluctance to move, and movement produced subtle intention tremors. Poisoned deer had extensive vacuolation of visceral tissues, which was most severe in the exocrine pancreas. Thyroid follicular epithelium, renal tubular epithelium, and macrophages in many tissues were mildly vacuolated. The exposed deer also had mild neuronal swelling and cytoplasmic vacuolation that was most obvious in Purkinje cells. Axonal swelling and dystrophy was found in many white tracts, but it was most severe in the cerebellar peduncles and the gracilis and cuneate fasciculi. These findings indicate that deer are susceptible to locoweed poisoning, but the lesions differ in severity and distribution from those of other species. The histologic changes of locoweed poisoning are distinct from those of CWD in deer; however, the clinical presentation of locoweed poisoning in deer is similar. Histologic and immunohistochemical studies are required for a definitive diagnosis.
Renal Myxozoanosis in Crowned River Turtles Hardella thurjii: Description of the Putative Agent Myxidium hardella n. sp. by Histopathology, Electron Microscopy, and DNA Sequencing
Authors: Garner M. M. , Bartholomew J. L. , Whipps C. M. , Nordhausen R. W. , Raiti P.
Published: September 2005

Chelonian myxozoanosis is rarely reported and has previously not been documented to cause disease. This report describes myxozoanosis associated with significant renal disease in two Crowned River turtles ( Hardella thurjii). One turtle presented with emaciation and died. The cage mate presented with emaciation and was euthanized. Histologically, renal intratubular myxozoan spores were associated with renal tubular necrosis, tubular mineralization, and chronic interstitial nephritis, with membranoproliferative and mes-angioproliferative glomerulopathy. Both turtles also had disseminated metastatic mineralization. On the basis of these findings, chronic renal insufficiency from myxozoanosis and subsequent metastatic mineralization were considered the primary problems. By light and electron microscopy, the myxozoan spores had features of the genus Myxidium. Maximum parsimony analysis of small-subunit rDNA sequences placed the turtle myxozoan basal to a clade containing Myxidium truttae and a Myxidium sp. with strong bootstrap support. This myxozoan agent appears to be a significant pathogen in H. thurjii on the basis of morphologic changes in the kidneys of in the infected turtles.
Expression of Connexins 26 and 43 in Canine Hyperplastic and Neoplastic Mammary Glands
Authors: Torres L. N. , Matera J. M. , Vasconcellos C. H. , Avanzo J. L. , Hernandez-Blazquez F. J. , Dagli M. L. Z.
Published: September 2005

Gap junctions are the only communicating junctions found in animal tissues and are composed of proteins known as connexins. Alterations in connexin expression have been associated with oncogenesis; reported studies in rodent and human mammary glands, which normally express connexins 26 and 43, confirm these alterations in malignancies. Mammary neoplasms represent the second most frequent neoplasm in dogs, and since there are no reports on the study of connexins in canine mammary glands, the present study investigated the expression of connexins 26 and 43 in normal, hyperplastic, and neoplastic mammary glands of this species, to verify if altered patterns of connexin staining are related to higher cell proliferation and malignant phenotypes. A total of 4 normal, 8 hyperplastic mammary glands, 9 benign, and 51 malignant mammary gland neoplasms were submitted for the immunostaining of connexins 26 and 43, E-cadherin, and proliferating cell nuclear antigen (PCNA). Normal, hyperplastic, and benign neoplastic mammary glands showed a punctate pattern for connexin 26 and 43 staining and an intercellular E-cadherin staining. Malignant neoplasms, especially the most aggressive cases with high cell proliferation rates, presented either fewer gap junction spots on the cell membranes or increased cytoplasmic immunostaining. Malignant tumors also expressed a less intense immunostaining of E-cadherin; the expression of this adhesion molecule is important for the transportation of connexins to cell membranes and in forming communicating gap junctions. Deficient expression of E-cadherin could be related to the aberrant connexin localization and may contribute to the malignant phenotype. In conclusion, the expression and distribution of connexins and E-cadherin are inversely correlated to cell proliferation in malignant mammary neoplasms of dogs and may well be related to their more aggressive histologic type and biologic behavior.
Hypertensive Encephalopathy in Cats with Reduced Renal Function
Authors: Brown C. A. , Munday J. S. , Mathur S. , Brown S. A.
Published: September 2005

The clinical, hemodynamic, and pathologic features of hypertensive encephalopathy in two cats with reduced renal mass are described. The cats developed a progressive syndrome of lethargy, ataxia, blindness, stupor, and seizures following an abrupt increase in blood pressure associated with a surgical reduction in renal mass. The cats had severe gross brain edema, evidenced by cerebellar changes of caudal coning and cranial displacement over the corpora quadrigemina and cerebral changes of widening and flattening of the gyri. Histologically, interstitial edema was most pronounced in the cerebral white matter. Hypertensive vascular lesions were present as hyaline arteriolosclerosis in one cat and hyperplastic arteriolosclerosis in the other. Rare foci of parenchymal microhemorrhages and necrosis were also observed. Systemic hypertension (especially severe or rapidly developing) accompanied by neurologic signs and the pathologic findings of diffuse brain edema with cerebral arteriolosclerosis are consistent with an etiologic diagnosis of hypertensive encephalopathy.
Genital Lesions Associated with Visceral Leishmaniasis and Shedding of Leishmania sp. in the Semen of Naturally Infected Dogs
Authors: Diniz S. A. , Melo M. S. , Borges A. M. , Bueno R. , Reis B. P. , Tafuri W. L. , Nascimento E. F. , Santos R. L.
Published: September 2005

Although visceral leishmaniasis is primarily transmitted by a biological invertebrate vector, transmission in the absence of the vector has been reported, including venereal transmission in humans. Considering the possibility of venereal transmission, we studied genital lesions in dogs naturally infected with visceral leishmaniasis and shedding of Leishmania sp. in the semen. Approximately 200 dogs were serologically tested for anti-Leishmania antibodies and divided into three groups: 1) serologically negative dogs ( n = 20), 2) asymptomatic serologically positive dogs ( n = 20), and 3) symptomatic serologically positive dogs ( n = 20). Samples from both testes, all segments of both epididymes, prostate gland, glans penis, and prepuce were histologically evaluated and processed for immunodetection of Leishmania sp. Semen samples were obtained from 22 symptomatic serologically positive dogs and processed for detecting Leishmania DNA by polymerase chain reaction. A significantly higher frequency of inflammation was observed in the epididymes, glans penis, and prepuce of dogs with visceral leishmaniasis, which was associated with a high frequency of immunohistochemically positive tissues (up to 95% of tissues from symptomatic dogs were positive by immunohistochemistry). Leishmania DNA was detected in eight of 22 semen samples from symptomatic dogs. Together these findings indicate that genital lesions and shedding of Leishmania sp. (donovani complex) in the semen are associated with visceral leishmaniasis. Additional studies should address the possibility of venereal transmission of the disease in the dog.
Funisitis Associated with Leptospiral Abortion in an Equine Placenta
Authors: Sebastian M. , Giles R. , Roberts J. , Poonacha K. , Harrison L. , Donahue J. , Benirschke K.
Published: September 2005

Funisitis, inflammation of the umbilical cord, is well recognized in human placentas. This report describes a case of funisitis associated with leptospiral infection in the placenta of a Thoroughbred foal born prematurely. The umbilical cord had diffuse superficial yellow discoloration along its entire length. Microscopic evaluation showed an exudate of neutrophils admixed with fibrin on the surface. Warthin-Starry staining showed spirochetes in the Wharton's jelly of the umbilical cord. A locally extensive, severe placentitis not involving the star and allantoic cystic hyperplasia were the other lesions observed in the allantochorion. Leptospira funisitis is similar to the funisitis of congenital syphilis in humans, although there are some major microscopic differences. in Leptospira funisitis, lesions were limited to the cord surface, whereas in lesions in human umbilical cords with Treponema pallidum infection, the changes are observed mostly around the vessels and in the Wharton's jelly.
Two Cases of Feline Malignant Craniopharyngioma
Authors: Nagata T. , Nakayama H. , Uchida K. , Uetsuka K. , Yasoshima A. , Yasunaga S. , Masuda K. , Tsujimoto H. , Kuwajima E. , Nishimura R. , Sasaki N. , Doi K.
Published: September 2005

Tumors at the cranial base in 2 cats (a 9 1/2-year-old, castrated male Chinchilla and a 7-year-old, castrated male American shorthair) were diagnosed as malignant craniopharyngioma. The tumor lesion was histopathologically divided into four parts: 1) a small acinus part, in which relatively large cells with a pale cytoplasm composed small acini; 2) a duct part, in which small cuboidal cells composed ducts; 3) a cyst part, in which there were large cysts lined with flat cells; and 4) a pavement part, in which large multiangular-shaped cells proliferated in a pavement pattern. The epithelial cells of some parts were positive for keratin by immunohistochemistry. Histopathologic findings of the present feline cases were identical to those of malignant craniopharyngioma in other animal species.
Putative Metronidazole Neurotoxicosis in a Cat
Authors: Olson E. J. , Morales S. C. , McVey A. S. , Hayden D. W.
Published: September 2005

A presumptive case of metronidazole toxicity in a 3.4-kg adult cat is described. The cat had been treated for suspected inflammatory bowel disease with an anti-inflammatory dose of prednisone and metronidazole (73.5-147 mg/kg PO q24h) for approximately 40 days prior to presentation. Clinical signs were primarily related to the central nervous system, including acute tetraparesis, unresponsiveness, tremors, and vocalization. The patient was euthanatized after 12 days of supportive care. Necropsy revealed no significant macroscopic lesions. Histologic evaluation revealed multifocal, fairly well-demarcated foci of necrosis in the brainstem, extending from the diencephalon to the medulla oblongata. To our knowledge, this is the first report to document histologic lesions associated with metronidazole administration in a cat.
Efficient production of native actin upon translation in a bacterial lysate supplemented with the eukaryotic chaperonin TRiC
Authors: Stemp Markus J. , Guha Suranjana , Hartl F. Ulrich , Barral José M.
Published: September 2005

Recombinant expression of actin in bacteria results in non-native species that aggregate into inclusion bodies. Actin is a folding substrate of TRiC, the chaperonin of the eukaryotic cytosol. By employing bacterial in vitro translation lysates supplemented with purified chaperones, we have found that TRiC is the only eukaryotic chaperone necessary for correct folding of newly translated actin. The actin thus produced binds deoxyribonuclease I and polymerizes into filaments, hallmarks of its native state. In contrast to its rapid folding in the eukaryotic cytosol, actin translated in TRiC-supplemented bacterial lysate folds with slower kinetics, resembling the kinetics upon refolding from denaturant. Lysate supplementation with the bacterial chaperonin GroEL/ES or the DnaK/DnaJ/GrpE chaperones leads to prevention of actin aggregation, yet fails to support its correct folding. This combination of in vitro bacterial translation and TRiC-assisted folding allows a detailed analysis of the mechanisms necessary for efficient actin folding in vivo. In addition, it provides a robust alternative for the production of substantial amounts of eukaryotic proteins that otherwise misfold or lead to cellular toxicity upon expression in heterologous hosts.
Hypothyroidism induces expression of the peptide transporter PEPT2
Authors: Döring Frank , Schmitt Roland , Bernhardt Wanja M. , Klapper Maja , Bachmann Sebastian , Daniel Hannelore , Groneberg David A.
Published: September 2005

The kidney is a target organ for thyroid hormone action and a variety of renal transport processes are altered in response to impaired thyroid functions. To investigate the effect of thyroid hormone on the expression of the renal proximal tubular high-affinity-type H+-peptide cotransporter (PEPT2) in rats, hypothyroidism was induced in animals by administration of methimazole (0.05%) via drinking water. After 7 weeks of treatment, hypothyroidism was confirmed by determining serum free T3 and free T4 concentrations. Northern blotting was used to examine the expression of PEPT2 mRNA in kidney tissues from hypothyroid rats compared to control rats. Hypothyroidism resulted in an increased level of total renal PEPT2 mRNA (121.1±3.3% vs. control 100±2.8%; p=0.008). The mRNA results were confirmed by immuno-blotting, which demonstrated significantly increased protein levels (162% vs. control 100%; p<0.01). Immunohistochemistry also revealed increased PEPT2 protein levels in the proximal tubules of treated compared to non-treated rats. In summary, PEPT2 is the first proximal tubule transporter protein that shows increased expression in states of hypothyreosis. As PEPT2 reabsorbs filtered di- and tripeptides and peptide-like drugs, the present findings may have important implications in nutritional amino acid homeostasis and for drug dynamics in states of altered thyroid function.
Heritability of Life History and Morphological Traits in a Wild Pink Salmon Population Assessed by DNA Parentage Analysis
Authors: Dickerson Bobette R. , Willson Mary F. , Bentzen Paul , Quinn Thomas P.
Published: September 2005

Heritability estimates were calculated for body size and shape, day of entry onto the spawning grounds, and egg size for two brood years (1997 and 1998) of a wild population of pink salmon Oncorhynchus gorbuscha based on parentage analysis of DNA samples from breeding adults and their mature offspring in a small creek in Southeast Alaska. The majority of heritability estimates for size and shape were not significantly different from zero, probably as a result of the close association of these variables with fitness. The even‐ and odd‐year brood lines are genetically isolated but heritability estimates from the two lines were significantly correlated, suggesting similar selection histories. Consistent with heritability estimates from controlled breeding and captive rearing of pink and other species of salmon, day of entry onto the spawning grounds had the highest heritabilities of the traits examined in this study, especially for males (h2 = 0.6– 1.38). One plausible method for the maintenance of genetic variation in entry timing (a trait important to fitness) is variation in the optimal spawning and emigration date from year to year owing to changes in flow rate, predation pressure, ocean conditions, and food availability for progeny.
An Argument for Pragmatism as a Foundational Philosophy of Occupational Therapy
Authors: Ikiugu Moses N. , Schultz Sally
Published: September 2005

Background. In 1986, Estelle Breines argued that occupational therapy identity problems could be resolved by acquiring tools that enable therapists to analyze their profession in a sophisticated manner. Breines identified philosophical inquiry as one of these tools. Purpose. This study examined how pragmatism can provide a philosophical framework for occupational therapy practice and knowledge. Method. An analysis of a sample of occupational therapy literature, philosophy of pragmatism literature, and Slagle lectures delivered between 1955 and 1995 was completed. Themes underlying the assumptions, principles, and values articulated in the literature and the Slagle lectures were identified and compared. Results. Findings of the analysis indicate that some of the core assumptions, principles, and values of occupational therapy as identified in occupational therapy literature and the Slagle lectures are conceptually consistent with those of the philosophy of pragmatism. Practice Implications. Pragmatism may provide a philosophical framework to organize the knowledge and practice of occupational therapy and assist with clarifying the profession's identity.
Mysteries and Mazes: Parents' Experiences of Children with Developmental Coordination Disorder
Authors: Missiuna Cheryl , Moll Sandra , Law Mary , King Susanne , King Gillian
Published: September 2005

Background. Children with Developmental Coordination Disorder (DCD) represent 5 to 6% of the school-aged population and are often seen by occupational therapists in the school system. Although a family-centred approach has been identified as best practice in pediatric care, the perspective of parents is often overlooked both in research and in practice. Purpose and Method. In this study, a qualitative, phenomenological approach was adopted to explore the insights and experiences of 13 parents of children with DCD. Each parent participated in two in-depth interviews and completed a set of questionnaires. Results. Analysis of the study findings led to three primary themes that captured the experience of parents as they attempted to understand and get help for their child. The theme of unravelling the mystery highlights parents' impressions of their child's difficulties. The second theme of negotiating the maze refers to the many pathways followed by families as they sought to affirm their perceptions and obtain services for their child and the final theme of parenting dilemmas underscores some of the common challenges faced by parents in trying to deal with their child's limitations. Practice Implications. For occupational therapists, the study findings illustrate the importance of focusing on occupational performance issues for children with DCD, facilitating the understanding of parents, and the need for early intervention.