Context Matching Research Articles

Identification of a nef allele that causes lymphocyte activation and acute disease in Macaque monkeys

Residues 17 and 18 In nef of SIVmac239 were changed from RQ to YE to create a translated sequence of SRP-SGDLYERLLRARGETYGRLLGEVEDGYSOSP from residues 10–43. The YXXL motifs In this context match very well with consensus sequences for SH2 binding domains and are similar to ones present In nef of the acutely lethal pathogen SIVpbj14. The YE variant of SIVmac239, unlike SIVmac239 but like SIVpbj14, replicated well in resting peripheral blood mononuclear cell cultures, caused extensive T lymphocyte activation, and produced an acute disease in rhesus and pigtailed monkeys characterized by severe diarrhea, rash, and extensive lymphoid proliferation In the gastrointestinal tract. The YEnef gene transformed NIH 3T3 cells in culture. Both 239nef and YEnef were found to associate with arc In cotransfected COS cells, and both 60 kDa arc and 34 kDa nef were phosphorylated at tyrosine in these cells. The extent of tyrosine phosphorylation of 239nef was considerably less than that of YEnef in these assays. These findings identify an important determinant of the SIVpbj14 phenotype, and they provide evidence of a role for nef in signal transduction and cellular activation.

Why was the macalot collection (Ps 120-134) written?

Why was the macalot collection (Ps 120-134) written? A dose reading of the macalot collection (Ps 120-134) proves that it is a work of unity and poetic worth. I f the ‘answer’ communicated by the text is ‘trust in Yahweh’, what might the ‘question’ or ‘problem’ be? How does the social context illuminate the text? With the sociological insights of C Geertz and W Brueggemann the sociological function of the collection is determined. Relevant sociohistoric data are used in reconstructing the possible social setting of the collection. Text and context match! The first in fact ‘mirrors’ the latter. The (macro-) context is that of disconsolation (ca 445-350 B C in Jerusalem) and a dire need for a message of trust and hope - which the text does provide. The theme of trust is given substance within the world view and ethos of Zion, national and Godwith- us-theology.

Alleviation of infantile amnesia in rats by internal and external contextual cues.

A previous study [Richardson, R., Riccio, D.C., and Jonke, T. (1983). Alleviation of infantile amnesia in rats by means of a pharmacological contextual state. Devel. Psychobiol., 16:511-518] found that ontogenetic forgetting ("infantile amnesia") in rats was attenuated by a "contextual matching" manipulation: Subjects trained in a distinct pharmacological state and tested in that state retained learned fear better than saline controls. To determine whether improved retention could be obtained with salient but nonpharmacological contexts, two experiments were conducted employing fear conditioning in preweanling rats. In Experiment 1, an internal context (illness induced by lithium chloride) present at training and testing reduced infantile forgetting. In Experiment 2, matching an exteroceptive context (home nest shavings) at training and testing was also found to be sufficient to alleviate infantile amnesia. In both experiments, retention was not improved in controls exposed to the context at training only or testing only, indicating that the contextual effect is not on acquisition or retrieval processes per se. These findings provide indirect support for views that emphasize the role of contextual cues in retrieval (Spear, 1978). In addition, they indicate that contextual matching is not limited to a state dependent drug, but may include a wide range of "distinctive" stimuli.

Latent inhibition from context-dependent retrieval of conflicting information

Rats were trained to lick and were tested for lick suppression to a tone in one apparatus/context. They were conditioned (tone-shock) in a different apparatus/context. Prior to conditioning, they received unreinforced preexposure to the tone (PCE) in the lick test box (Group A), in the conditioning box (Group X), or in a box different from both the test and conditioning boxes (Group B), or they received no PCE (Group N). In both Experiments 1 and 2, Group A was the only group to show latent inhibition (i.e., to show less conditioned lick suppression than did Group N). Context-dependent retrieval of “this CS signals nothing” information acquired during PCE reduces lick suppression when PCE and test contexts match, but not when PCE and conditioning contexts match.

Contextual Template Matching: A Distance Measure for Patterns with Hierarchically Dependent Features

Contextual template matching refers to situations where the feature sets of the two templates under consideration may not be identical, but are rather contingent on the context within which these templates are observed. This paper addresses context-dependent template matching where the relevancy of certain features to a given object is contingent on the value of higher level features. In such situations portions of the patterns for two objects X and Y may not be comparable, and therefore classical distance measures are not applicable. A framework for describing pattern spaces with hierarchically dependent features-named conditional pattern spaces (CPS)-is presented, and a distance measure for comparing objects in a CPS is developed and illustrated on archaeological objects. This measure satisfies several desired properties of distance measures, such as the metric requirements.

Pitch of components of complex tones.

Subjects made pitch matches to individual components in complex tones consisting of either the 4th to 7th or the 1st to 7th harmonics of a 200-Hz fundamental. All components were at equal levels (either 31-, 51-, or 71-dB SPL per component) and the matching pure tone was equal in level to the component being matched. Attention was drawn to the component to be matched either by giving the matching tone an initial frequency close to that of the component (standard condition) or by suppressing and then introducing the component (emergent condition). The pitch matches did not differ significantly for the two conditions, and did not change with overall level. For two subjects, matches to components in the context of the complexes were very close to matches obtained for the components presented in isolation. For a third subject, matches in context were shifted slightly upwards for the lowest component, and downwards for the highest component. A control condition showed that subjects were able accurately to match a small shift in frequency of one component in a four-tone complex. An adaptive forced-choice method described by Jesteadt [Percept. Psychophys. 28, 85-88 (1980)] was also used to estimate the pitches of the components. A very slight bias was apparent in the results, but the pitches of components in context were again found to be very close to those of components in isolation.