cssi/SciSciGPT-SciSciNet huggingface dataset:
Customer response to intangible and tangible service factors

This research investigates the question: Does the physical environment of service delivery settings influence customers' evaluations of the service experience and subsequent behavioral intentions? Theoretical and empirical data from environmental psychology suggests that customer reactions to the tangible physical environment may be more emotional than cognitive, particularly when involving hedonic consumption. This article integrates environmental psychology into SERVQUAL (a current measure of service quality) to enable a fuller assessment of the role of the tangible aspects of service delivery. Based on consumer surveys in three leisure service settings, the findings are that the tangible physical environment plays an important role in generating excitement in leisure settings; excitement, in turn, plays a significant role in determining customers repatronage intentions and willingness to recommend. © 1999 John Wiley & Sons, Inc.
Comparability of Scores from Performance Assessments.

Why is comparability of forms important for performance assessments? Can traditional methods of form equating be used? What problems are likely to arise in equating? Can standards generalize across forms?
Isolated inferior rectus paresis secondary to a mesencephalic cavernous angioma.

Abstract PURPOSE: To report a case of recurrent binocular, vertical diplopia presenting as an isolated, unilateral inferior rectus paresis occurring in a patient with a mesencephalic tegmental cavernous angioma. METHOD: Case report. A 30-year-old man with recurrent vertical diplopia underwent neuro-ophthalmic examination, laboratory examination, pharmacologic testing, and magnetic resonance imaging and angiography. RESULTS: Magnetic resonance imaging disclosed a lesion in the mesencephalon consistent with a cavernous angioma. Magnetic resonance angiography was negative. CONCLUSIONS: Isolated inferior rectus paresis is a rare phenomenon. This unique case involved a patient with recurrent inferior rectus paresis secondary to a mesencephalic cavernous angioma. The disparity between the extent of the lesion and the neuro-ophthalmologic consequences is remarkable.
Melting and Resolidification of a Subcooled Mixed Powder Bed With Moving Gaussian Heat Source

Melting of a subcooled powder bed that contains a mixture of two powders with significantly different melting points under a moving Gaussian heat source was investigated numerically. Shrinkage induced by the density change on the melting process was taken into account in the physical model. The problem is formulated using a temperature transforming model and solved by the finite difference method. The results show that the effect of surface heat loss due to convection and radiation is not negligible regardless of whether the shrinkage phenomena is considered. The decrease of moving heat source intensity will result in decrease of the sintering depth and the volume of the liquid pool. The increase of the scanning velocity will decrease the sintering depth and the location and shape of the liquid pool is affectea significantly.
Trying Again: Power-Sharing in Post-Civil War Lebanon

The paper situates Lebanon in the context of consociationalist theorizing about politics in deeply divided societies. It suggests that none of the four prevailing models of Middle Eastern political systems (liberalism, patrimonial, nationalist-authoritarian, and corporatist) explicitly addresses vertical solidarist formations. Consociationalism attempts to do so, but Lebanon's experience with it has yielded negative as well as positive results. The paper reviews the contradictions of Lebanon's recent history, examining first ``the golden age'' and then the era of the civil war and the ``militia republic'' (1975–1990). It then analyzes the ``Ta'if Accord'' which provided the basis for a post-civil war reconstruction, and while it notes some institutional improvements (hence the designation of the agreement as ``consociationalism-plus'') it expresses skepticism whether the provisions in Ta'if that call for the gradual elimination of political confessionalism will be implemented. The paper draws attention to the presence of external players on the Lebanese scene, especially Israel and Syria, and discusses the two post-civil war parliamentary elections in 1992 and 1996. It concludes that Lebanon's political recovery has been only partly successful.
Impact ionization current in MOS devices

Abstract An impact ionization current flows in the substrate of an MOS device which is operated in the saturation region. This current results from hole-electron pairs created by impact ionization in the drain depletion region. This paper utilizes the transverse electric field across the depletion region and the probability of creating a hole-electron pair as a function of this field to calculate substrate current which is then compared with measured data.
smogd: software for the measurement of genetic diversity.

Software for the measurement of genetic diversity (SMOGD) is a web-based application for the calculation of the recently proposed genetic diversity indices G′ST and Dest. SMOGD includes bootstrapping functionality for estimating the variance, standard error and confidence intervals of estimated parameters, and SMOGD also generates genetic distance matrices from pairwise comparisons between populations. SMOGD accepts standard, multilocus Genepop and Arlequin formatted input files and produces HTML and tab-delimited output. This allows easy data submission, quick visualization, and rapid import of results into spreadsheet or database programs.
SIALOGLYCOPROTEIN AND GLYCOLIPIDS IN CULTURED FIBROBLASTS FROM PATIENTS WITH CYSTIC FIBROS IS

Cystic fibrosis (CF) is an autosomal recessive disease affecting the exocrine glands and manifested by increased sweat electrolytes, viscous pancreas and lung secretions, leading to pancreatic and pulmonary insufficiency. Cultured skin fibroblasts from patients with CF and normal individuals were utilized for the study of glycoprotein and glycolipid metabolism. Cells were grown in modified Eagle's medium until confluency (2-3 weeks). Sialic acid content was determined in the CF fibroblasts and was compared to the normal controls. The levels of sialic acid were 3 to 8 fold increased in the CF fibroblasts. The incorporation of 14C-acetate in the glycoprotein and glycolipid fractions of cultured CF and normal fibroblasts was determined. CF fibroblasts showed 2 to 10 fold increase of the label in the glycolipid and glycoprotein fractions. Chlostridium sialidase released 30% of the label indicating incorporation of acetate into sialic acid. N-acetyl groups from glycoprotein of normal and CF cells were estimated, and found to be 18.5% and 14.0% respectively. The O-acetyl groups in the normal cells represented 13% of the total radioactivity while in the CF fibroblasts only 2.5%. Methanolysis of the deacetylated residue showed the incorporation of label into glycolic acid and the methylglycoside of sialic acid. Labeled glucosamine, mannosamine, mannose, fucose and galactose showed similar incorporation in CF and normal cells. The increased levels of sialic acid and the incorporation of acetate by CF cells may afford a new tool for the study of CF in tissue culture.
Office space allocation optimization

In large organizations, the allocation of buildings and office space to departments and employees is a challenging task. Optimal office space allocation has the potential to maximize synergies between employees within an organization. In this paper, we study the performance of a greedy search algorithm and a tabu search algorithm for generating high quality solutions to the office space allocation problem. The objectives are to maximize synergies in the organization, minimize the overusage of limited office space and maximize the number of buildings and rooms that can be completely closed. Computational experiments show that a tabu search algorithm generates higher quality solutions than a greedy local search algorithm with the same computational budget.
Visual servo control of an unmanned ground vehicle via a moving airborne monocular camera

The Euclidean position and orientation (i.e., pose) of an unmanned ground vehicle (UGV) is typically required for autonomous navigation and control. In this paper, a collaborative visual servo controller is developed with the objective to regulate an UGV to a desired pose utilizing the feedback from a moving airborne monocular camera system. In contrast to typical camera configurations used for visual servo control problems, the controller in this paper is developed using a moving on-board camera viewing a moving target. Multi-view photogrammetric methods are used to develop relationships between different camera frames and UGV coordinate systems. Lyapunov-based methods are used to prove asymptotic regulation.
Optical Particle Sizing For Hydrodynamics: Further Results

An Optical method for instantaneous measurement of suspended particle size distribution shows promise for the study of boundary layer dynamics in the ocean, where suspended particles affect boundary layer flow through stratification. The method is based on observing the an-gular distribution of scattered light from a sample, and inversion to produce the suspended particle size distribution, n(x). In a previous paper, an analytic inversion based on the Fraunhoffer approximation was examined. The function 03I(0) was found approximately to be related by a Fourier transform to xn(x), with the result that elementary signal processing concepts apply. In this work, the issues of uniqueness and stabilty of the inversion are considered. Instability of inversion for small particles is observed, and has the result that while matrix inversion algorithms show promise, those which manipulate small eigenvalues distort inversions for small sizes. Uniqueness in terms of sampling is revisited, yielding a refined Nyquist sampling criterion. The validity of these results, derived from approximate diffraction theory, is demonstrated for "exact" Mie theory.© (1986) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Representation as Shared Activity: Situated Cognition and Dewey's Cartography of Experience

Dewey described the continuity of experience and the interaction of individuals with their environments as longitude and latitude for locating educative experience. This article examines three aspects of Dewey's Pragmatist philosophy as intellectual roots for current work in situated cognition. These aspects are used to organize a case analysis of two teachers working together to solve and design instruction for a typical algebra problem. The analysis focuses on interactional phenomena and argues that these phenomena are usually left out of studies of cognition and that they are critically important for understanding effective teaching. A close analysis of interaction supports a view of representation as shared activity, as an alternative to traditional cognitive accounts that focus exclusively on an individual's mental structures. In the moment-to-moment production and explanation of inferences about the mathematical structure of a problem, representations are activities in which these teachers are joint...
Hand gesture recognition using ensembles of radial basis function (RBF) networks and decision trees

Hand gestures are the natural form of communication among people, yet human-computer interaction is still limited to mice movements. The use of hand gestures in the field of human-computer interaction has attracted renewed interest in the past several years. Special glove-based devices have been developed to analyze finger and hand motion and use them to manipulate and explore virtual worlds. To further enrich the naturalness of the interaction, different computer vision-based techniques have been developed. At the same time the need for more efficient systems has resulted in new gesture recognition approaches. In this paper we present an hybrid intelligent system for hand gesture recognition. The hybrid approach consists of an ensemble of connectionist networks — radial basis functions (RBF) — and inductive decision trees (AQDT). Cross Validation (CV) experimental results yield a false negative rate of 1.7% and a false positive rate of 1% while the evaluation takes place on a data base including 150 images corresponding to 15 gestures of 5 subjects. In order to assess the robustness of the system, the vocabulary of the gestures has been increased from 15 to 25 and the size of the database from 150 to 750 images corresponding now to 15 subjects. Cross Validation (CV) experimental results yield a false negative rate of 3.6% and a false positive rate of 1.8% respectively. The benefits of our hybrid architecture include (i) robustness via query by consensus as provided by ensembles of networks when facing the inherent variability of the image formation and data acquisition process, (ii) classifications made using decision trees, (iii) flexible and adaptive thresholds as opposed to ad hoc and hard thresholds and (iv) interpretability of the way classification and retrieval is eventually achieved.
General methods for enriching aldoses with oxygen isotopes

Synthetic methods are described for enriching 4-, 5-, and 6-carbon aldoses with oxygen isotopes. The general approach includes exchange between H2(1)8O and the aldehyde group of an aldose, exchange of O-1 onto C-2 of both of the 2-epimeric aldoses formed by molybdate-resin epimerization, and chain extension using cyanide addition. These methods make possible the production of all 16 aldohexoses enriched at 5 of the 6 oxygen atoms, all 8 aldopentoses enriched at 4 of the 5 oxygen atoms, and the four aldotetroses enriched at 2 of the 4 oxygen atoms. The general applicability of these methods is illustrated by the synthesis of a group of 22 different, 18O-enriched, biologically important D-aldoses having 4, 5, and 6 carbon atoms. The group includes D-[1-, 2-, 3-, 4-, O]glucose, D-[1-, 2-, 3-, 4-, and 6-18O]mannose, D-[1-, 2-, 3-, and 5-18O]arabinose, D-[1- abd 2- 18O] erythorose, and D-[1- and 2-18O]threose. The g.l.c.-m.s. characterization of these sugars with respect to the position and degree of 18O-enrichment is reported. The potential of the methods for producing aldoses having oxygen labels at multiple positions, or aldoses labeled simultaneously with oxygen, hydrogen, and carbon isotopes is discussed.
Formation of Recombinant Triple-Helical [α1(IV)]2α2(IV) Collagen Molecules in CHO Cells

Abstract Collagen IV molecules represent a major structural component of basement membranes providing a network of support for the supramolecular structure. Like other collagens, collagen IV forms a triple-helical molecule composed of three α chains. Six different α chains exist for collagen IV, although the most common isoform consists of two α1(IV) and one α2(IV) chain. To understand the molecular mechanism of triple-helical formation of collagen IV, we expressed recombinant α1(IV) and α2(IV) mouse collagen chains in Chinese hamster ovary (CHO) cells. An expression vector containing the full length cDNA for the mouse α1(IV) chain was stably transfected into CHO cells and a cell line, A222, which expressed recombinant α1(IV) chains was selected. These A222 cells were then infected with a retroviral expression vector containing the mouse α2(IV) chain and a cell line, A222-A2, stably expressing both recombinant α1(IV) and α2(IV) chains was obtained. Immunoprecipitation of A222 cell lysates revealed a high level of α1(IV) chain monomer, which was unable to form a homotrimer. Analysis of A222-A2 cell lysates revealed the presence of both monomeric α2(IV) and α1(IV) chains as well as a higher molecular weight collagen IV species. Second dimensional SDS-PAGE analysis demonstrated that the high molecular weight species was a heterotrimer consisting of two α1(IV) and one α2(IV) chain. This heterotrimer collagen IV species was pepsin-resistant indicating the formation of a stable triple-helical structure. Pulse-chase experiments showed that the monomer α1(IV) chain was secreted, but at a much slower rate than the heterotrimer. Together these results demonstrate that the α1(IV) chain is not capable of forming homotrimers and suggest that the coexpression with the α2(IV) chain is necessary to form a triple-helical structure.
From Stereotype Threat to Stereotype Threats: Implications of a Multi-Threat Framework for Causes, Moderators, Mediators, Consequences, and Interventions

More than 100 articles have examined the construct of stereotype threat and its implications. However, stereotype threat seems to mean different things to different researchers and has been employed to describe and explain processes and phenomena that appear to be fundamentally distinct. Complementing existing models, the authors posit a Multi-Threat Framework in which six qualitatively distinct stereotype threats arise from the intersection of two dimensions--the target of the threat (the self/one's group) and the source of the threat (the self/outgroup others/ingroup others). The authors propose that these threats constitute the core of the broader stereotype threat construct and provide the foundation for understanding additional, as of yet uncharacterized, stereotype threats. The proposed threats likely differentially peril those with different stigmatizable characteristics, have different eliciting conditions and moderators, are mediated by somewhat different processes, are coped with and compensated for in different ways, and require different interventions to overcome.
Long-Lead Water Supply Forecast Using Large-Scale Climate Predictors and Independent Component Analysis

Interest in water supply forecasting has grown prominently due to population growth and increasing demands for water. One important aspect of successfully managing the supply of water is accurate and reliable forecasts of seasonal streamflow volumes. Much of the streamflow in mountainous regions is a result of the collection of seasonal snowpack over the winter months and the melting of this snowpack over the spring and summer. However, there has been increasing pressure on operational agencies to issue longer-lead water supply forecasts that would be released in late fall or early winter preceding the runoff season. Longer-lead forecasts are difficult to make due to the uncertainty in future winter and spring climate conditions and the lack of snowpack information. During the late fall and early winter, large-scale oceanic and atmospheric information can provide insight into future climate conditions and spring runoff and have shown to be useful in developing long-lead forecast. In this study, statistica...
Comparative vs. Noncomparative Advertising: Perspectives on Memory

Abstract This research begins by offering a transfer appropriate processing (TAP) view of memory to explain the conflicting findings in the comparative advertising literature involving the potential memory differences between comparative and noncomparative advertising. TAP theory proposes that memory can be explained by the interaction between encoding and retrieval. This study then tests memory from a TAP perspective in a comparative versus noncomparative context. The findings suggest that one form of advertising is not necessarily superior to another in enhancing memory. Additionally, the two broader perspectives of memory, passive versus active, are discussed in relation to the findings. In the process, the question of appropriateness is discussed through which the possibility for conjoining the passive and active views of memory becomes evident. A reconciled view of memory is offered and implications of the research are discussed. Future directions for consumer memory research are also provided.
Relationship of outcomes of methotrexate/misoprostol abortion to prior pregnancy experience∗

Objective: Prior pregnancy has been associated with increased rates of suction curettage in previous analysis of early medical abortion using methotrexate and misoprostol (P <0.004). However, neither the mechanism nor the contribution of subgroups to outcome differences has been clarified. Methods: Information from 1,973 patients in a multicenter case series of women undergoing abortion with methotrexate and misoprostol at 49 days or less was used. We used χ2 statistics and logistic regression (SAS, Inc.); P <0.05 was considered significant. Results: Suction curettage rates ranged from 9.6% to 17.7%; the lowest rate (9.6%) was among never-pregnant women. Women with prior abortion, but no prior births, had higher rates of curettage than never-pregnant women (12.1%). Women with prior induced abortion only (n = 412) had rates of curettage of 11.4%, and women with prior spontaneous abortion only (n = 31) had rates of 12.9% (NS). Women with prior birth had the highest rates of suction curettage (15.6%). Women with prior vaginal birth only (n = 767) had rates of curettage of 15.0%, whereas women with prior abdominal deliveries only (n = 113) had rates of 17.7% (NS). Curettage and parity (para 1, 14.4%; para 2, 16.4%; para 3, 14%; para 4, 10%) did not show a trend with increasing parity. Conclusion: The observed increase in curettage with prior pregnancy and birth compared with never-pregnant women does not appear to be influenced by mode of delivery, cause of abortion, or increasing parity.
Heritable ectopic mineralization disorders: the paradigm of pseudoxanthoma elasticum.

Skin diseases characterized by aberrant accumulation of mineral deposits comprise a heterogeneous group of disorders, often associated with inflammation (Sprecher, 2010). Examples of such conditions are systemic autoimmune disorders, for example, dermatomyositis, lupus erythematosus, and systemic sclerosis. Localized inflammatory lesions, such as those in acne and skin cancers, can also develop localized foci of mineralization. The mechanisms of ectopic mineralization in these relatively common conditions are largely unknown. However, clues to the mineralization processes affecting the skin have emerged from studies on rare heritable single gene disorders with profound mineralization of the skin. The paradigm of such mineralization disorders is pseudoxanthoma elasticum (PXE), a multi-system disease with protean manifestations in the skin, the eyes, and the cardiovascular system (Neldner, 1988). In fact, the significant milestones of progress made in understanding this disorder serve as examples of the power of molecular genetics towards identification of the candidate genes and pathogenic mutations, with translational implications (Uitto et al., 2010, 2011).
High-frequency reflections in granite? delineation of the weathering front in granodiorite at Pinon Flat, California

We analyze data from two orthogonal seismic lines 336 m in length collected at Pinon Flat, California, over weathered granodiorite bedrock. Each line was made up of 10 reversed segments 84 m in length. We analyzed the first arrivals from these data and found dramatic variations in velocity along the profiles. An upper layer (approximately 2-m thick) known from trenching to be composed of soil and sandy grus had measured velocities ranging from 400 to 700 m/s. Velocities inferred from refraction analysis of first arrivals of the reversed lines revealed a heterogeneous lower layer below the soil with measured velocities of 1600–2700 m/s by a depth of 15 m. We interpret these data to be measuring velocities of a deeply weathered unit characterized by granodiorite corestones embedded in a matrix of saprolite. The most remarkable feature of these data emerged from attempting to process the same data as reflection data. Simple bandpass filtering in the 250–400 Hz band revealed a bright, impulsive arrival with t...
Are Cognitive Changes Progressive in Prediagnostic HD

Objective: To characterize neurocognitive signs of disease progression in prediagnosis and early Huntington disease (HD) and compare the sensitivity of 2 disease staging classification schemes for detecting these signs. Methods: Three hundred and six individuals at-risk for or recently diagnosed with HD completed the Unified Huntington's Disease Rating Scale, genetic testing, and a neurocognitive battery. Two schemes were used to estimate latency to onset of disease. One was based on genetic information (CAG repeat length) and the other was based on the extent of motor signs. Effect sizes were compared to assess the relative sensitivity of the 2 schemes for detecting signs of disease progression. Results: CAG-expanded participants far from estimated diagnosis performed similarly to controls, whereas those near to estimated diagnosis were impaired relative to controls. Overall, the method employing genetic information yielded larger effect sizes than the motor scheme, particularly for strategic and executive function measures; the motor scheme resulted in a larger effect size for a measure of motor/psychomotor function. Conclusions: Neurocognitive function is not uniformly affected in prediagnosis and early HD; individuals near to their estimated age of diagnosis have cognitive signs similar to HD, whereas individuals far from estimated diagnosis appear cognitively normal. Classification schemes that incorporate both genetic and phenotypic information may be more sensitive for tracking neurocognitive signs of disease progression.
Effect of CH4-starvation on atmospheric CH4 oxidizers in Taiga and temperate forest soils

Abstract The soil organisms that consume atmospheric CH 4 in upland ecosystems have not been identified. Whether these organisms benefit from oxidizing atmospheric CH 4 or whether CH 4 is cooxidized fortuitously is uncertain. We investigated the general nutritional physiology of atmospheric CH 4 oxidizers occurring in three forest soils by starving them of CH 4 for 1–2 months and monitoring their abilities to consume atmospheric CH 4 over time. In two Alaskan taiga forest soils, CH 4 starvation caused the atmospheric CH 4 oxidizers to lose their ability to consume CH 4 , indicating that they benefitted from oxidizing atmospheric CH 4 , possibly requiring it for maintenance and growth. In contrast, the organisms in a temperate hardwood forest soil from Massachusetts maintained their ability to consume atmospheric CH 4 despite prolonged CH 4 deprivation, suggesting that they either cooxidized CH 4 fortuitously, or that they used alternative substrates for maintenance and growth. These results may point to diverse nutritional physiologies among atmospheric CH 4 oxidizers.
Comparison of optimal controls for a model in cancer chemotherapy with L 1- and L 2-type objectives

We consider a two-compartment model for cancer chemotherapy as optimal control problems with drug dosages as controls and with objectives which are linear, respectively quadratic. While optimal controls are bang-bang in case of an L 1-objective, they are continuous in the L 2-case; but they still ‘switch’ between values in the interior and values in the boundary of the control set. On the basis of sufficient conditions for strong local optimality developed earlier in this article for various cases of L 1- and L 2-objective, the advantages and disadvantages of using these type of objectives in cancer chemotherapy are discussed. E-mail: hms@wustl.edu This material is based on work supported by the National Science Foundation under grant No. 0205093. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
Standardization of neutron spectrum unfolding codes: Tests using idealized, calculated response functions

Abstract There exists a variety of methodologies and computer codes for analyzing proton recoil spectra from fast neutron scintillation spectrometers. To evaluate these procedures a series of tests have been performed using idealized, calculated response functions. These tests have been designed to eliminate inherent differences usually involved in comparisons between matrix “inversion” and “derivative” method codes. The tests indicate that some codes give significantly more accurate results than others. In particular, several derivative method codes seem to be consistently more accurate than matrix “inversion” codes, although this result must be interpreted cautiously. These results give, for the first time, a systematic methodology to test a wide variety of proton recoil unfolding codes and provide a basis for further tests using “real” proton recoil response functions.
Use of animal studies in risk assessment for immunotoxicology

Abstract We have previously reported on the design and content of a screening battery involving a ‘tier’ approach for detecting potential immunosuppressive compounds in mice. This battery has been used to examine a variety of compounds, and the database generated from these studies, which consists of over 50 compounds, has been collected and analyzed in an attempt to improve the accuracy and efficiency of screening chemicals for immunosuppression and to identify better those tests that predict experimentally-induced, immune-mediated diseases. Specifically, these analyses attempted to develop an improved testing configuration for the accurate prediction of immunotoxic agents and to provide insight into the qualitative and quantitative relationships between a number of immune and host resistance assays commonly employed to examin potential immunotoxic chemicals in experimental animals. While a number of limitations existed in the analyses, several conclusions were drawn from the results which will be discussed.
Should Medicare Compensate Hospitals for Administratively Necessary Days

Days that a patient remains in a hospital due to inability to secure nursing home placement are termed administratively necessary days (ANDs). Some hospitals under Medicare's prospective payment system have incurred discharge delays of this kind. Nursing home bed supply is one major problematic factor; others include adequacy of Medicare nursing home reimbursement rates relative to nursing home costs in an area, the willingness of facilities in an area to serve those needing skilled care, and stringency of relevant Medicaid reimbursement policy. Two promising approaches for dealing with ANDs are increasing nursing home reimbursement rates, and adjusting Medicare payments for exceptionally long-staying patients or those requiring exceptionally intensive care in hospitals.
Transport Coefficients in Degenerate Fermi Systems

A method of calculating the transport coefficients of a degenerate Fermi system is described and compared with previous approaches. Applications to dilute mixtures of ${\mathrm{He}}^{3}$ in liquid ${\mathrm{He}}^{4}$ and to nearly ferromagnetic Fermi liquids are given.
Efficient modification of the APRT gene by FLP/FRT site-specific targeting

The FLP/FRT site-specific recombination system was established and characterized at the APRT gene in CHO cells. Targeting frequencies with FLP-stimulation were about 1 to 5×10−5, which were 6–22-fold above gene targeting frequencies in the absence of FLP. Fifty two APRT+ cell lines were analyzed by Southern blotting: 56% were FLP-targeted integrants; 33% were APRT target convertants; 11% gave undefined patterns. In separate experiments we first enriched for integrants by screening for two additional markers carried on the targeting vector; 18 of 19 (95%) of the resulting cell lines were integrants. Intrachromosomal site-specific recombination was tested by reexposing integrants to FLP. Intrachromosomal popouts were stimulated over 200-fold, while homologous recombination in an adjacent interval was unchanged. The utility of this system was demonstrated by one-step FLP targeting to generate chromosomal substrates for homologous recombination, and by a two-step, FLP-and-run procedure to construct a chromosomal substrate for illegitimate recombination.
Intrafamilial child sexual abuse: predictors of postdisclosure maternal belief and protective action.

The two purposes of this study were to determine the percentage of nonoffending, biological mothers who were concordant for belief and protection of their sexually abused children and to examine maternal, child, and situational characteristics that predict such concordance. Data were collected on a sample of 435 mothers. Descriptive statistics and logistic regression were utilized to identify the proportion and the predictors of maternal belief and protective action. Findings indicated that mothers were more likely to believe and protect when they postponed the birth of their first child until reaching adulthood, when they were not a current sexual partner of the offender, when they did not have knowledge of the sexual abuse prior to the child's disclosure, and when the victim did not exhibit sexualized behavior. These findings have the potential to enhance the efficacy of child welfare interventions by underscoring the importance of maternal belief and protection. Further empirical study is recommended to investigate predictors of ambivalent maternal responses to her child's sexual victimization. Language: en
Healing response of normal canine aorta and iliac artery to a nitinol stent encapsulated in carbon-lined ePTFE.

PURPOSE To evaluate the healing response of normal canine arteries to a self-expanding nitinol stent encapsulated in carbon-lined expanded polytetrafluoroethylene (ePTFE). METHODS Twenty-eight dogs were divided into aortic (n = 18) or iliac (n = 10) groups. In the latter, 2 animals were assigned to implantation intervals of 7, 30, and 90 days, respectively; 4 were designated for 180-day implantation. Half of the animals in each subgroup received a second overlapping stent-graft in one iliac artery. In the aortic cohort, 6 animals were assigned to the 180-day implantation group (2 with dual devices) and 3 to each of the others (1 dual implantation in each group). The devices were evaluated with angiography and intravascular ultrasound at implantation and explantation. After harvesting and gross examination, the specimens were examined microscopically and with scanning electron microscopy. RESULTS The 49 implanted devices (24 aortic and 25 common iliac) were all widely patent at explantation, save for 2 iliac stents that had moderate (<40%) stenosis. No neointima was present at the 7-day interval. All stents were covered by thin neointima (<150 microm) at 30 days. At 180 days, an endothelial lining was present in the proximal and distal segments of all stents; in 4 of the 6 aortic stents, this endothelial lining was complete, whereas none of the iliac devices had endothelium in the midsegment at 180 days. At 1 year, 2 of the aortic specimens had an incomplete endothelial lining, whereas the lining was complete in the third. There was no evidence of stent-graft migration or inflammation associated with any device. CONCLUSIONS The carbon-lined ePTFE-encapsulated stent is a novel approach to arterial stenting. The progressive endothelialization and lack of inflammatory reaction may provide improved long-term patency. Further study of this stent-graft design is warranted.
Estrogenic activity of coumestrol and related compounds

Abstract A study was made of the estrogenic activity of 29 compounds related to the plant estrogen, coumestrol. A number of correlations of structure with activity were observed. Acetylation of both hydroxyl groups did not decrease activity. Etherification of both hydroxyl groups decreased estrogenic activity by 2 3 . The 4′-O-methylcoumestrol was less active than the 7-O-methylcoumestrol, and neither was as active as coumestrol. Opening the lactone ring of coumestrol to form the potassium salt of the resulting o-hydroxycinnamic acid did not decrease activity. Formation of the o-methoxycinnamic acid derivative decreased activity greatly. Opening of the furan ring also greatly decreased estrogenic activity. Removal of one of the two hydroxyl groups of coumestrol decreased activity to about 1 6 of the original, and removal of both hydroxyl groups completely eliminated the estrogenic response. The presence of additional hydroxyl groups on the coumestrol molecule greatly diminished estrogenic activity.
Soluble stromal factors enhance gene transfer in primitive human hematopoietic cells in mobilized peripheral blood

Abstract Hematopoietic stem cells present mobilized peripheral blood (MPB) are attractive targets for retroviral gene therapy. Previously, we have found that in contrast to primitive hematopoietic cells in umbilical cord blood, primitive cells in G-CSF MPB are not efficiently transduced. Based on earlier studies demonstrating a positive effect of the fetal liver stromal cell line AFT024 on the maintenance of primitive hematopoietic cells ex vivo , we hypothesized that AFT024 may enhance the level of gene transfer (GT) into these cells. To test this hypothesis, CD34 + cells from G-CSF MBP were cultured in the presence or absence of irradiated AFT024 cells using trans-well (non-contact) cultures for 4 days with either G-CSF, SCF and TPO (GST; 100 ng/mL) or Flt3-L, SCF, IL-7 and TPO (FS7T; 10-20 ng/mL), followed by infection on two consecutive days with a GALV-pseudotyped MFG-EGFP retroviral vector on fibronectin fragment FN CH-296 (Retronectin®, Takara Shuzo). Cultured and transduced cells were evaluated for the level of expansion as well as for the level of GT in CFC and LTC-IC assays. AFT024 enhanced the expansion of CFC and LTC-IC (1.5 to 2-fold). The level of GT in CFC (ranging from 1 to 26% in BFU-E and CFU-GM; n=10) was higher in the groups pre-stimulated with GST as compared to FS7T. In contrast, the level of GT in LTC-IC (ranging from 1.5 to 47%) was higher with FS7T (n=6), but only in the presence of AFT024. Finally, the overall recovery of transduced LTC-IC in the presence of AFT024 with FS7T was 6-fold higher as compared to our previously used strategy using GST in the absence of stroma (p
Promoting Participation? An Examination of Rulemaking Notification and Access Procedures

This study documents state implementation of mechanisms designed to promote public participation in agency rulemaking. Many scholars have questioned the effectiveness of such mechanisms, arguing that they fail to encourage greater participation or that increased participation does not affect the substance of administrative rules. Using data from a unique survey of state administrators, the author employs multivariate analyses to assess the relationship between these measures and the perceived influence of external actors. The results suggest that critics may understate the importance of public notification and access procedures. These devices are associated with increases in the impact that a wide variety of actors are perceived to have on the content of agency rules.
A CAMAC/NIM system for data acquisition and monitoring of drift chambers

Abstract We describe a CAMAC/NIM system for the calibration and readout of drift chambers. The basic system consists of 2 CAMAC and 2 NIM modules and is easily extendable.
Membrane potentials of BHK (baby hamster kidney) cell line: ionic and metabolic determinants.

The transmembrane potential of cells from a continuous cell line (BHK-21) has been investigated by a combination of electrophysiological and flame photometric techniques. The ratio of sodium permeability to potassium permeability (PNa/PK) determined from membrane potentials recorded at varying external potassium concentrations was 0.082; from membrane potential measurements and the intracellular sodium and potassium concentrations of cells in 6.8 mM K+ media the value was 0.075. The PNa/PK ratio was not temperature dependent. Dinitrophenol (1 mM) did not significantly alter the membrane potential of cells incubated for one hour with the inhibitor. However, iodoacetate (1 mM) and sodium fluoride (30 mM) caused a significant depolarization during a one-hour incubation. Measurements of sodium and potassium concentrations during incubation at 4°C showed a decrease in internal potassium and an increase in internal sodium accompanied by a decreased membrane potential. Ion concentrations and membrane potentials were measured in cells recovering at 37°C following 24 hours at 4°C. Membrane potentials in excess of EK during the first ten minutes of recovery may indicate electrogenic pumping.
The projection of three extrathalamic cell groups to the cerebral cortex of the turtle Pseudemys.

Three extrathalamic subcortical inputs to the part of the cerebral cortex that is known to receive thalamic fibers in the turtle were examined in the present study. Direct projections from the locus coeruleus, the superior medial raphe nucleus, and a wide area of the basal telencephalon that lies ventromedial to the globus pallidus were demonstrated with the horseradish peroxidase method. Fluorescence histochemistry confirmed the presence of catecholamine-containing fibers in the rostral half of dorsal cortex and also demonstrated a dense network of serotoninergic fibers. Biochemical analysis showed the concentration of both monoamines to be relatively high; the norepinephrine concentration was 709 ng/g and the serotonin concentration was 1,750 ng/g. No evidence was found to suggest the existence of either a dopamine fiber projection to cortex comparable to that of mammalian neocortex or the presence of an epinephrine pathway to turtle cortex equivalent to the epinephrine-containing fibers in the pallium of amphibians. The coexistence of the projections from the thalamus with (1) noradrenergic projections from the locus coeruleus, (2) serotoninergic projections from the superior medial raphe nucleus, and (3) presumably cholinergic projections from the basal telencephalon provide at least four distinct subcortical inputs to the reptilian dorsal cortex. Neither thalamic nor similar extrathalamic inputs have been demonstrated in the dorsal pallium of amphibia. Mammalian neocortex, in contrast, has even more elaborately differentiated inputs of both types. These results support the idea that thalamic and extrathalamic inputs to cortex appear at the same time in vertebrate evolution, and that both types of inputs are required for the normal development and function of neocortex.
Posttranscriptional Silencing of Effector Cytokine mRNA Underlies the Anergic Phenotype of Self-Reactive T Cells

SUMMARY Self-reactive T cell clones that escape negative selection are either deleted or rendered functionally unresponsive (anergic), thus preventing them from propagating host tissue damage. By using an in vivo model, we investigated molecular mechanisms for T cell tolerance, finding that despite a characteristic inability to generate effector cytokine proteins, self-reactive T cells express large amounts of cytokine mRNAs. This disconnect between cytokine message and protein was not observed in T cells mounting productive responses to foreign antigens but, instead, was seen only in those responding to self, where the block in protein translation was shown to involve conserved AU-rich elements within cytokine 3 0 UTRs. These studies reveal that translation of abundant cytokine mRNAs is limited in selfreactive T cells and, thus, identify posttranscriptional silencing of antigen-driven gene expression as a key mechanism underlying theanergicphenotypeofselfreactive T cells.
Spontaneous Desorption: Field Assisted Ion-Induced Desorption Mass Spectrometry.

Abstract Spontaneous desorption (SD) has been studied as a function of field strengths and sputtering energies. Accordingly, the mechanism of SD is proposed to be a two step process. The first step is the field desorption of ions from a grid or aperture. This step is evidenced by the dependence of the electron count rate versus the electric field strength. The first step is also the ‘rate determining step’. The second step is the sputtering of the sample surface by the field desorbed ions. This step is evidenced by the large difference in ion yields at the same field strength but different incident ion energies. The SD effect is also present in other techniques that rely on a potential difference between the sample and a grid to extract desorbed or ionized particles.
Observations on the abdominal stretch receptor and the fine structure of associated axo-dendritic synapses and neuromuscular junctions in homarus.

The abdominal stretch receptor of lobster has been examined. Fine structural details of the receptor nerves are presented and neurophysiological correlations are suggested. Both axo-dendritic synapses and neuromuscular junctions were examined. Axo-dendritic synapses are of one type only, possessing elongated, or flattened, presynaptic vesicles approximately 200 A in diameter and 400–600 A long. In contrast two distinct types of neuromuscular junctions were observed. The first possesses spherical synaptic vesicles 500–900 A in diameter. The second possesses synaptic vesicles of dimensions similar to those of axo-dendritic synapses. It is suggested that synapses, both axo-dendritic and neuromuscular, with elongated or flattened vesicles, are inhibitory, and that neuromuscular junctions with spherical vesicles are excitatory.
A little help from my friends: quality control of presecretory proteins in bacteria.

All organisms, including bacteria, localize a fraction of all of their proteins partially or completely outside of the cytosol. Along the way, these proteins must cross at least one hydrophobic lipid membrane. The remarkable feat of delivering proteins across tightly sealed membranes is achieved largely by complex secretion machineries known as translocons. These machines recognize their substrates via signal sequences, which are required for proper targeting to the translocon. The bulk of protein transport across the inner cytoplasmic membrane is facilitated by the well-known general secretory (Sec) pathway, but additional categories for transport into or across the inner membrane, including the recently discovered twin-arginine translocation (Tat) pathway, exist. More-specialized mechanisms for targeting proteins to the inner membrane, the outer membrane, or the extracellular environment also exist and are reviewed elsewhere (19, 31, 71). Proteins targeted to the Sec pathway achieve membrane translocation through the Sec translocon, a proteinaceous conduit formed by an oligomeric assembly of the heterotrimeric membrane protein complex SecYEG (7, 79) and the peripheral ATPase SecA as a molecular motor (26). Sec substrates traverse the membrane in a largely unfolded state and effectively thread their way through the pore. In stark contrast to the Sec-dependent threading of unstructured substrates, the Tat pathway has the unique ability to transport proteins that have attained a substantial degree of tertiary or even quaternary structure in the cytoplasm prior to membrane translocation (13, 22, 35, 66, 70). This process is enabled by a translocon consisting of the TatA, TatB, TatC, and TatE proteins, which share little homology with the components of the Sec translocon. Consistent with these distinct modes of translocation, both the Sec and Tat pathways have evolved unique measures for surveying the quality of their respective substrates. This minireview will discuss how the proper structural integrity of proteins to be transported (hereinafter referred to as preproteins) is ensured during the early stages of Sec and Tat targeting so that these proteins remain compatible with their respective macromolecular transport machineries.
Quantitative study of large composite-fermion systems

Quantitative investigations of the fractional quantum Hall effect (FQHE) have been limited in the past to systems containing typically fewer than 10{endash}12 particles, except for the 1/(2p+1) Laughlin states. We develop a method, using the framework of the composite-fermion theory, that enables a treatment of much bigger systems and makes it possible to obtain accurate quantitative information for other incompressible states as well. After establishing the validity of this method by comparison with few-particle exact-diagonalization results, we compute the ground-state energies and transport gaps for a number of FQHE states. {copyright} {ital 1997} {ital The American Physical Society}