Positive correlation of responsiveness to catecholamines of the rat liver glycogenolytic receptor with other α-receptor responses

Zusammenfassung Durch die vollständige Dosis-Wirkungskurve der Katecholamin-i.p.-induzierten Leber-Glykogenolyse an der Ratte konnte deren Einfluss auf die -Rezeptoren nachgewiesen werden. Da eine Wirkung auf die -Rezeptoren (Lipolyse) ausschied, konnte es sich nur um einen -Effekt handeln.     

Additive and synergistic inhibition of mammalian microsomal enzyme functions by piperonyl butoxide,safrole and other methylenedioxyphenyl derivatives

Zusammenfassung Piperonylbutoxyd, Methylendioxylanilin, Methyleugenol, Safranol und Vanillylamin bewirken eine additive Hemmung der Funktion mikrosomaler Enzyme in Mäusen, wenn sie zusammen in Dosen verabreicht werden, die einzeln inaktiv sind. Piperonylbutoxyd und Safranol induzieren synergistisch die Hemmung von Aminopyrenedemethylase-Aktivität. Es erfolgte keine synergistische Hemmung nach kombinierter Behandlung mit Pib. und hohen Dosen der strukturell verwandten, aber inaktiven Piperonylsäure.

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Supported by N.I.H. Grants No. C-6516 and No. Fr-05526.

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We thank Mrs.M. Sengupta and Mr.E. Greene for their technical assistance.     

Activities of catecholamines on the rat muscle glycogenolytic (β-2) receptor

Zusammenfassung Es wird gezeigt, dass der Glykogen-Rezeptor im Rattenmuskel vom Standpunkt der Reaktion mit den Katecholaminen als-2 anzusehen ist.     

Mutations in Rab3a alter circadian period and homeostatic response to sleep loss in the mouse

Rab3a is the most abundant Rab (ras-associated binding) protein in the brain and has a regulatory role in synaptic vesicle trafficking. Mice with a targeted loss-of-function mutation in Rab3a have defects in Ca(2+)-dependent synaptic transmission: the number of vesicles released in response to an action potential is greater than in wildtype mice, resulting in greater synaptic depression and the abolishment of CA3 mossy-fiber long term potentiation. The effect of these changes on behavior is unknown. In a screen for mouse mutants with abnormal rest-activity and sleep patterns, we identified a semidominant mutation, called earlybird, that shortens the circadian period of locomotor activity. Sequence analysis of Rab3a identified a point mutation in the conserved amino acid (Asp77Gly) within the GTP-binding domain of this protein in earlybird mutants, resulting in significantly reduced levels of Rab3a protein. Phenotypic assessment of earlybird mice and a null allele of Rab3a revealed anomalies in circadian period and sleep homeostasis, providing evidence that Rab3a-mediated synaptic transmission is involved in these behaviors.     

Motion-induced spatial conflict

Borders defined by small changes in brightness (luminance contrast) or by differences in colour (chromatic contrast) appear to move more slowly than those defined by strong luminance contrast. As spatial coding is influenced by motion, if placed in close proximity, the different types of moving border might appear to drift apart. Using this configuration, we show here that observers instead report a clear illusory spatial jitter of the low-luminance-contrast boundary. This visible interaction between motion and spatial-position coding occurred at a characteristic rate (approximately 22.3 Hz), although the stimulus motion was continuous and invariant. The jitter rate did not vary with the speed of movement. The jitter was not due to small involuntary movements of the eyes, because it only occurred at a specific point within the stimulus, the low-luminance-contrast boundary. These findings show that the human visual system contains a neural mechanism that periodically resolves the spatial conflict created by adjacent moving borders that have the same physical but different perceptual speeds.     

Presence of hepcidin-25 in biological fluids: Bile,ascitic and pleural fluids

AIM: To examine body fluids such as ascitic fluid (AF),saliva,bile and pleural effusions for the presence of hepcidin using a novel radioimmunoassay (RIA).METHODS: Serum samples were collected from 25 healthy volunteers (mean age: 36 ± 11.9 years,11 males,14 females).In addition bile was obtained from 12 patients undergoing endoscopic retrograde cholangiopancreatography (mean age: 66.9 ± 16.7 years,M:F = 5:7).Saliva was collected from 17 healthy volunteers (mean age: 35 ± 9.9 years,M:F = 8:9).Pleural and AF...     

Computing the variance of the forecast error for the holt-winters seasonal models

This paper presents expressions for the variance of the forecast error for arbitrary lead times for both the additive and multiplicative Holt-Winters seasonal forecasting models. It is shown that even when the smoothing constants are chosen to have values between zero and one, when the period is greater than four, the variance may not be finite for some values of the smoothing constants. In addition, the regions where the variance becomes infinite are almost the same for both models. These results are of importance for practitioners, who may choose values for the smoothing constants arbitrarily, or by searching on the unit cube for values which minimize the sum of the squared errors when fitting the model to a data set. It is also shown that the variance of the forecast error for the multiplicative model is nonstationary and periodic.     

Structure of a human common cold virus and functional relationship to other picornaviruses

We report the first atomic resolution structure of an animal virus, human rhinovirus 14. It is strikingly similar to known icosahedral plant RNA viruses. Four neutralizing immunogenic regions have been identified. These, and corresponding antigenic sequences of polio and foot-and-mouth disease viruses, reside on external protrusions. A large cleft on each icosahedral face is probably the host cell receptor binding site.     

Breeding ecology of White-faced Ibis ( Pleagadis chihi ) in the Upper Klamath Basin, California

The White-faced Ibis ( Plegadis chihi ) is a California state and U.S. Fish and Wildlife Service species of special management concern. We studied White-faced Ibis breeding ecology from May through July 1995 on Lower Klamath National Wildlife Refuge (NWR) in the upper Klamath Basin of California. A total of 2029 pairs nested in 3 colonies exclusively in early-successional hardstem bulrush ( Scirpus acutus ). Nest initiation dates ranged from 10 May to 12 June, and mean clutch size was 3.16. Reproductive success averaged 87% apparent nest success ( n = 115), 82% hatchability, 97% whole and partial brood survival, and 2.39 fledglings per successful nest. Mayfield estimates of nest survival were 79.1% during the laying and incubation period and 95% during the nestling period. Overall nest success as estimated by the Mayfield method was 75.4%. Our estimates of nest success are some of the highest reported anywhere in the literature for White-faced Ibis. Therefore, Lower Klamath NWR may maintain preferred White-faced Ibis breeding habitats in years of otherwise poor habitat conditions across the Intermountain West.