1,608 research outputs found
Studies in the catchment area of the Central Amazonian rain forest stream "Barro Branco" on the "terra firme". II. Discharge of the stream
Untersucht wurde die jΓ€hrliche AbfluΓspende des tropischen Waldbaches Barro Branco (Reserva Ducke, km 26 StraΓe Manaus - Itacoatiara, Amazonas, Brasilien) im Zeitraum von September 1976 bis September 1977. Dabei wurde eine AbfluΓspende aus dem Einzugsgebiet (1,30 kmΒ²) von 20 % ermittelt. Dies weist auf die groΓe Bedeutung der Evapotranspiration im tropischen Regenhochwald der "terra firme" hin. Eine Vernichtung des Waldes wird mit Sicherheit zu verstΓ€rkter Erosion fΓΌhren
Study of led lamp power supply
Π Π΄Π°Π½Π½ΠΎΠΉ ΡΡΠ°ΡΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΡΠ΅ΡΡΡ ΠΈΡΡΠΎΡΠ½ΠΈΠΊ ΠΏΠΈΡΠ°Π½ΠΈΡ ΡΠ²Π΅ΡΠΎΠ΄ΠΈΠΎΠ΄Π½ΠΎΠ³ΠΎ ΡΠ²Π΅ΡΠΈΠ»ΡΠ½ΠΈΠΊΠ° Ρ Π²ΡΡΠΎΠΊΠΈΠΌΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠΎΠΌ ΠΌΠΎΡΠ½ΠΎΡΡΠΈ. ΠΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½Π° ΠΌΠΈΠΊΡΠΎΡΡ
Π΅ΠΌΠ° ΠΊΠΎΡΡΠ΅ΠΊΡΠΎΡΠ° ΠΊΠΎΡΡΡΠΈΡΠΈΠ΅Π½ΡΠ° ΠΌΠΎΡΠ½ΠΎΡΡΠΈ ΠΊΠΎΠΌΠΏΠ°Π½ΠΈΠΈ STMicroelectronics L6561 Π² ΠΎΠ±ΡΠ°ΡΠ½ΠΎΡ
ΠΎΠ΄ΠΎΠ²ΠΎΠΉ ΡΠΎΠΏΠΎΠ»ΠΎΠ³ΠΈΠΈ. Π‘ ΠΏΠΎΠΌΠΎΡΡΡ ΡΡΠΎΠΉ ΠΌΠΈΠΊΡΠΎΡΡ
Π΅ΠΌΡ ΡΠΏΡΠΎΡΠ°Π΅ΡΡΡ ΠΏΠΎΡΡΡΠΎΠ΅Π½ΠΈΠ΅ ΠΈΡΡΠΎΡΠ½ΠΈΠΊΠ° ΠΏΠΈΡΠ°Π½ΠΈΡ, ΡΡΠΈΡΡΠ²Π°Ρ ΡΡΠ°Π½Π΄Π°ΡΡΡ ΡΠ½Π΅ΡΠ³ΠΎΡΠ±Π΅ΡΠ΅ΠΆΠ΅Π½ΠΈΡ ΠΈ ΡΡΠ΅Π±ΠΎΠ²Π°Π½ΠΈΡ ΠΊ ΡΡΠΎΠ²Π½Ρ Π²Π½ΠΎΡΠΈΠΌΡΡ
Π² ΠΏΠΈΡΠ°ΡΡΡΡ ΡΠ΅ΡΡ ΠΈΡΠΊΠ°ΠΆΠ΅Π½ΠΈΠΉ.In this article, we investigate the LED lamp power supply with a high power factor. To implement this, the power factor corrector of STMicroelectronics L6561 is used in the fly-back topology. With the help of this IC simplifies the construction of the power supply, considering energy-efficiency standards and requirements for the level introduced into the mains distortion.Fir filter design using frequency sampling method
Spike-phase coupling patterns reveal laminar identity in primate cortex
The cortical column is one of the fundamental computational circuits in the brain. In order to understand the role neurons in different layers of this circuit play in cortical function it is necessary to identify the boundaries that separate the laminar compartments. While histological approaches can reveal ground truth they are not a practical means of identifying cortical layers in vivo. The gold standard for identifying laminar compartments in electrophysiological recordings is current-source density (CSD) analysis. However, laminar CSD analysis requires averaging across reliably evoked responses that target the input layer in cortex, which may be difficult to generate in less well-studied cortical regions. Further, the analysis can be susceptible to noise on individual channels resulting in errors in assigning laminar boundaries. Here, we have analyzed linear array recordings in multiple cortical areas in both the common marmoset and the rhesus macaque. We describe a pattern of laminar spike-field phase relationships that reliably identifies the transition between input and deep layers in cortical recordings from multiple cortical areas in two different non-human primate species. This measure corresponds well to estimates of the location of the input layer using CSDs, but does not require averaging or specific evoked activity. Laminar identity can be estimated rapidly with as little as a minute of ongoing data and is invariant to many experimental parameters. This method may serve to validate CSD measurements that might otherwise be unreliable or to estimate laminar boundaries when other methods are not practical
Does a narrative retelling task improve the assessment of language proficiency in school-aged children born very preterm?
Almost half of the children born very preterm (VP) experience language difficulties at school-age, specifically with more complex language tasks. Narrative retelling is such a task. Therefore, we explored the value of narrative retelling assessment in school-aged children born VP, compared to item-based language assessment. In 63 children born VP and 30 age-matched full-term (FT) controls Renfrewβs Bus Story Test and Clinical Evaluation of Language Fundamentals were assessed. The retelling of the Bus Story was transcribed and language complexity and content measures were analyzed with Computerised Language Analysis software. Narrative outcomes of the VP group were worse than that of the FT group. Group differences were significant for the language complexity measures, but not for the language content measures. However, the mean narrative composite score of the VP group was significantly better than their mean item-based language score, while in the FT group the narrative score was worse than the item-based score. Significant positive correlations between narrative and item-based language scores were found only in the VP group. In conclusion, in VP children narrative retelling appears to be less sensitive to detecting academic language problems than item-based language assessment. This might be related to the mediating role of attention in item-based tasks, that appears not to affect more spontaneous language tasks such as retelling. Therefore, in school-aged children born VP we recommend using narrative assessment, in addition to item-based assessments, because it is more related to spontaneous language and less sensitive to attention problems
Structure of a robust bacterial protein cage and its application as a versatile biocatalytic platform through enzyme encapsulation
Using a newly discovered encapsulin from Mycolicibacterium hassiacum, several biocatalysts were packaged in this robust protein cage. The encapsulin was found to be easy to produce as recombinant protein. Elucidation of its crystal structure revealed that it is a spherical protein cage of 60 protomers (diameter of 23 nm) with narrow pores. By developing an effective coexpression and isolation procedure, the effect of packaging a variety of biocatalysts could be evaluated. It was shown that encapsulation results in a significantly higher stability of the biocatalysts. Most of the targeted cofactor-containing biocatalysts remained active in the encapsulin. Due to the restricted diameters of the encapsulin pores (5β9 Γ
), the protein cage protects the encapsulated enzymes from bulky compounds. The work shows that encapsulins may be valuable tools to tune the properties of biocatalysts such as stability and substrate specificity
How should a virtual agent present psychoeducation?
BACKGROUND AND OBJECTIVE: With the rise of autonomous e-mental health applications, virtual agents can play a major role in improving trustworthiness, therapy outcome and adherence. In these applications, it is important that patients adhere in the sense that they perform the tasks, but also that they adhere to the specific recommendations on how to do them well. One important construct in improving adherence is psychoeducation, information on the why and how of therapeutic interventions. In an e-mental health context, this can be delivered in two different ways: verbally by a (virtual) embodied conversational agent or just via text on the scree
Goal-Directed and Habitual Control in Smokers.
INTRODUCTION: Harmful behavior such as smoking may reflect a disturbance in the balance of goal-directed and habitual control. Animal models suggest that habitual control develops after prolonged substance use. In this study, we investigated whether smokers (N = 49) differ from controls (N = 46) in the regulation of goal-directed and habitual behavior. It was also investigated whether individual differences in nicotine dependence levels were associated with habitual responding. METHODS: We used two different multistage instrumental learning tasks that consist of an instrumental learning phase, subsequent outcome devaluation, and a testing phase to measure the balance between goal-directed and habitual responding. The testing phases of these tasks occurred after either appetitive versus avoidance instrumental learning. The appetitive versus aversive instrumental learning stages in the two different tasks modeled positive versus negative reinforcement, respectively. RESULTS: Smokers and nonsmoking controls did not differ on habitual versus goal-directed control in either task. Individual differences in nicotine dependence within the group of smokers, however, were positively associated with habitual responding after appetitive instrumental learning. This effect seems to be due to impaired stimulus-outcome learning, thereby hampering goal-directed task performance and tipping the balance to habitual responding. CONCLUSIONS: The current finding highlights the importance of individual differences within smokers. For future research, neuroimaging studies are suggested to further unravel the nature of the imbalance between goal-directed versus habitual control in severely dependent smokers by directly measuring activity in the corresponding brain systems. IMPLICATIONS: Goal-directed versus habitual behavior in substance use and addiction is highly debated. This study investigated goal-directed versus habitual control in smokers. The findings suggest that smokers do not differ from controls in goal-directed versus habitual control. Individual differences in nicotine dependence within smokers, however, were positively associated with habitual responding after appetitive instrumental learning. This effect seems to be due to impaired stimulus-outcome learning, thereby hampering goal-directed task performance and tipping the balance to habitual responding. These findings add to the ongoing debate on habitual versus goal-directed control in addiction and emphasize the importance of individual differences within smokers
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