ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Digitale Medien

Interferon induction of (2′–5′) oligoisoadenylate synthetase in diploid and trisomy 21 human fibroblasts: Relation to dosage of the interferon receptor gene (IRFC) (1983)

Weil, J. ; Tucker, Georgianne ; Epstein, L. B. ; [weitere]

Springer

Human genetics 〈Berlin〉 65 (1983), S. 108-111

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1203

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie , Medizin

Notizen: Summary Trisomy 21 human fibroblasts are more sensitive to human interferon-α (IFN-α) than are diploid controls, consistent with the location of the gene (IFRC) which codes for the IFN-α receptor on chromosome 21. When compared in the antiviral assay, the difference in sensitivity is five-to tenfold, much greater then the 50% difference in IFRC gene dosage. An understanding of the mechanism by which this amplification of gene dosage occurs is relevant to the specific pathology of Down's syndrome and as a model system for studying the pathogenic effects of chromosomal aneuploidy. The enzyme (2′–5′) oligoisoadenylate synthetase (2–5A synthetase), which is believed to be central to the interferon-induced antiviral response, is induced 50% more in trisomy 21 fibroblasts than in diploid controls. Thus the amplification in response occurs subsequent to the binding of IFN-α to its receptor and the triggering of the first set of intracellular events, the latter exemplified by the induction of 2–5A synthetase. Similar results were obtained with IFN-γ, consistent with other evidence which indicates that a gene coding for a separate IFN-γ receptor is also located on chromosome 21.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00286644

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

2

Digitale Medien

Ouabain binding in rectal gland ofSqualus acanthias (1983)

Silva, Patricio ; Epstein, Jonathan A. ; Stevens, Arthur ; [weitere]

Springer

The journal of membrane biology 75 (1983), S. 105-114

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1424

Schlagwort(e): shark rectal gland ; ouabain binding ; (Na, K)-ATPase ; cyclic AMP ; slices ; isolated cells

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie , Chemie und Pharmazie

Notizen: Summary In an attempt to examine the mechanisms of activation of (Na, K)-ATPase when epithelial transport is stimulated, the binding of ouabain to rectal gland tissue was measured before and after stimulation with dibutyryl cAMP and theophylline. Stimulation significantly altered the characteristics of ouabain binding to slices ofSqualus acanthias rectal gland and to isolated rectal gland cells, accelerating the rate of binding and increasing the amount of ouabain bound at equilibrium when low concentrations of ouabain (10−9 to 10−7 m) were present in the medium. Scatchard plots of ouabain binding were nonlinear, suggesting at least two classes of binding sites, one of higher and one of lower affinity. Stimulation with cAMP and theophylline appeared to increase the affinity of the high-affinity site. Ouabain binding was increased by cAMP and theophylline even in the presence of furosemide (10−4 m) or bumetanide (10−5 m), and when Li+ was substituted for Na+, or NO 3 − for Cl−-maneuvers known to inhibit rectal gland secretion. The changes in ouabain binding induced by cAMP and theophylline do not appear, therefore, to be secondary to secretory activity but may reflect a change in the configuration, environment or location of existing enzyme so as to enhance its activity. Stimulation of ouabain binding cannot be demonstrated in whole homogenates of rectal gland, indicating that intact cells are necessary for the cyclic AMP-induced increase in ouabain binding to become manifest.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF01995630

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

3

Digitale Medien

Cyclic AMP stimulates ouabain-insensitive ion movement in shark rectal gland (1984)

Silva, Patricio ; Spokes, Kate ; Epstein, Jonathan A. ; [weitere]

Springer

Journal of comparative physiology 154 (1984), S. 139-144

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-136X

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie , Medizin

Notizen: Summary When the active sodium-potassium pump (Na−K-ATPase) of shark rectal glands is blocked by ouabain, the concentration of intracellular ions changes in the direction of equilibrium with extracellular fluid. These changes were examined when isolated perfused glands were in the basal state and also when they were stimulated to secrete with cAMP and theophylline, to see whether stimulation affected the passive movement of sodium, potassium and chloride across cell membranes. In basal glands 10−4M ouabain induced an increase of 30 meq/l in intracellular [Na+] and a decrease in intracellular [K+] of about 50 meq/l after 30 min, while intracellular [Cl−] was unchanged. In stimulated glands, these movements were exaggerated. The increase in intracellular [Na+] averaged 112 meq/l, and the decrease in intracellular [K+], 96 meq/l (P〈0.01), while mean intracellular [Cl−] rose by 80 meq/l. Furosemide, 10−4M, partially reversed the accelerated changes in intracellular electrolytes seen after ouabain was added to stimulated glands. These results are consistent with an action of cAMP upon a ouabaininsensitive cotransport of sodium, potassium and chloride in the rectal gland, analogous to that described in avian erythrocytes.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00684137

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

4

Digitale Medien

Automatic rezeroing of drifting physiologic signals (1980)

Epstein, R. A. ; Epstein, M. A. F.

Springer

Medical & biological engineering & computing 18 (1980), S. 746-748

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1741-0444

Schlagwort(e): Autozeroing ; Barometric method ; Electronic circuit ; Instrumentation ; Plethysmography

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie , Chemie und Pharmazie , Medizin

Notizen: Abstract An electronic circuit is described which automatically rezeroes a physiologic signal whenever it reaches the limit of a display. This modified signal can be used for polygraph monitoring while the raw signal is processed by a wide-range high-resolution a.d. convertor. The device is currently used in conjunction with the barometric method for measuring tidal volume, but should find general use in plethysmography.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF02441900

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

5

Digitale Medien

Optical second-harmonic generation in atomic calcium vapour (1981)

Arkhipkin, V. G. ; Makarov, N. P. ; Popov, A. K. ; [weitere]

Springer

Optical and quantum electronics 13 (1981), S. 436-438

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1572-817X

Quelle: Springer Online Journal Archives 1860-2000

Thema: Elektrotechnik, Elektronik, Nachrichtentechnik , Physik

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00620280

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

6

Digitale Medien

A partially ordered extention of the integers (1995)

Epstein, George ; Rasiowa, Helena

Springer

Studia logica 54 (1995), S. 303-332

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1572-8730

Quelle: Springer Online Journal Archives 1860-2000

Thema: Mathematik , Philosophie

Notizen: Abstract This paper presents a monotonic system of Post algebras of order ω+ω* whose chain of Post constans is isomorphic with 0≤1≤2≤ ... ≤-3≤-2≤-1. Besides monotonic operations, other unary operations are considered; namely, disjoint operations, the quasi-complement, succesor, and predecessor operations. The successor and predecessor operations are basic for number theory.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF01053003

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

7

Digitale Medien

Learning Game-Specific Spatially-Oriented Heuristics (1998)

Epstein, Susan L. ; Gelfand, Jack ; Lock, Esther

Springer

Constraints 3 (1998), S. 239-253

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1572-9354

Schlagwort(e): machine learning ; game playing ; spatial cognition ; extensible architectures

Quelle: Springer Online Journal Archives 1860-2000

Thema: Informatik

Notizen: Abstract This paper describes an architecture that begins with enough general knowledge to play any board game as a novice, and then shifts its decision-making emphasis to learned, game-specific, spatially-oriented heuristics. From its playing experience, it acquires game-specific knowledge about both patterns and spatial concepts. The latter are proceduralized as learned, spatially-oriented heuristics. These heuristics represent a new level of feature aggregation that effectively focuses the program's attention. While training against an external expert, the program integrates these heuristics robustly. After training it exhibits both a new emphasis on spatially-oriented play and the ability to respond to novel situations in a spatially-oriented manner. This significantly improves performance against a variety of opponents. In addition, we address the issue of context on pattern learning. The procedures described here move toward learning spatially-oriented heuristics for autonomous programs in other spatial domains.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1023/A:1009734028965

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

8

Digitale Medien

Aligning simulation models: A case study and results (1996)

Axtell, Robert ; Axelrod, Robert ; Epstein, Joshua M. ; [weitere]

Springer

Computational & mathematical organization theory 1 (1996), S. 123-141

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1572-9346

Schlagwort(e): Simulation ; replication ; computational models ; alignment ; culture

Quelle: Springer Online Journal Archives 1860-2000

Thema: Mathematik

Notizen: Abstract This paper develops the concepts and methods of a process we will call “alignment of computational models” or “docking” for short. Alignment is needed to determine whether two models can produce the same results, which in turn is the basis for critical experiments and for tests of whether one model can subsume another. We illustrate our concepts and methods using as a target a model of cultural transmission built by Axelrod. For comparison we use the Sugarscape model developed by Epstein and Axtell. The two models differ in many ways and, to date, have been employed with quite different aims. The Axelrod model has been used principally for intensive experimentation with parameter variation, and includes only one mechanism. In contrast, the Sugarscape model has been used primarily to generate rich “artificial histories”, scenarios that display stylized facts of interest, such as cultural differentiation driven by many different mechansims including resource availability, migration, trade, and combat. The Sugarscape model was modified so as to reproduce the results of the Axelrod cultural model. Among the questions we address are: what does it mean for two models to be equivalent, how can different standards of equivalence be statistically evaluated, and how do subtle differences in model design affect the results? After attaining a “docking” of the two models, the richer set of mechanisms of the Sugarscape model is used to provide two experiments in sensitivity analysis for the cultural rule of Axelrod's model. Our generally positive experience in this enterprise has suggested that it could be beneficial if alignment and equivalence testing were more widely practiced among computational modelers.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF01299065

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

9

Digitale Medien

How hiring: Dogs and humans need not apply (1999)

Epstein, Richard G.

Springer

Ethics and information technology 1 (1999), S. 227-236

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1572-8439

Quelle: Springer Online Journal Archives 1860-2000

Thema: Informatik , Philosophie

Notizen: Abstract This is a review of Hans Moravec's book, Robot: Mere Machine to Transcendent Mind. This review raises three categories of questions relating to Moravec's vision of the future. First, there are the ethical and social implications issues implicit in robotics research. Second, there are the soul issues, which especially relate to the prospect of the demoralization of human beings. Third, there is the issue as to whether a robot could ever be a sentient being.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1023/A:1010064106064

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

10

Digitale Medien

Evidence for abnormal regulation of circulating 1α,25-dihydroxyvitamin D in patients with pulmonary tuberculosis and normal calcium metabolism (1984)

Epstein, Sol ; Stern, Paula H. ; Bell, Norman H. ; [weitere]

Springer

Calcified tissue international 36 (1984), S. 541-544

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-0827

Schlagwort(e): 1α25(OH)2D ; Hypercalcemia ; Normocalcemia ; Pulmonary tuberculosis

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie , Medizin , Physik

Notizen: Summary Available evidence indicates that hypercalcemia in pulmonary tuberculosis results from increases in circulating 1α,25-dihydroxyvitamin D [1α,25(OH)2D]. To further characterize vitamin D metabolism in this disorder, the effects of vitamin D, 100,000 units a day for 4 days, were compared in 25 normal subjects and 11 patients with active pulmonary tuberculosis who were normocalcemic and had not had hypercalcemia. Serum calcium, phosphorus, 25-hydroxyvitamin D (25-OHD) and 1α,25(OH)2D were measured. Whereas vitamin D increased mean serum 25-OHD from 20±2 (±SE) to 40±5 ng/ml (P〈0.001) and did not change mean serum 1α,25(OH)2D in the normals (33±2 vs. 31±2 pg/ml), it increased mean serum 25-OHD from 21±4 to 55±13 ng/ml (P〈0.05) and mean serum 1α,25(OH)2D from 28±2 to 35±3 pg/ml (P〈0.05) in the patients. Serum calcium was normal and remained within the normal range in all subjects and patients. The findings indicate that there is a modest but significant abnormality in the regulation of circulating 1α,25(OH)2D in normocalcemic patients with pulmonary tuberculosis. The results are similar to those previously reported by us in normocalcemic patients with sarcoidosis.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF02405362

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext