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A challenging problem in the computational modeling of meaning is representing abstract words and emotional connotations. Three simulations are presented that demonstrate that the Hyperspace Analogue to Language (HAL) model of memory encodes the meaning of abstract and emotional words in a cognitively plausible fashion. In this paper, HAL's representations are used to predict human judgements from word meaning norms for concreteness, pleasantness, and imageability. The results of a single-word priming experiment that utilized emotional and abstract words was replicated. These results suggest that it is unnecessary to posit separate lexicons to account for dissociations in priming results. HAL uses global co-occurrence information from a large corpus of text to develop word meaning representations. Representations of words that are abstract or emotional are formed no differently than concrete words.

The Hyperspace Analogue to Language (HAL) model is a methodology for capturing semantics from a corpus by analysis of global co-occurrence. A priming experiment from Lund et al. (1995) which did not produce associative priming with humans or in the HAL simulation is repeated with rearranged control trials. Our experiment now finds associative priming with human subjects, while the HAL simulation again does not produce associative priming. Associative word norms are examined in relation to HAL's semantics in an attempt to illuminate the semantic bias of the model. Correlations with association norms are found in the temporal sequence of words within the corpus. When the associative norm data are split according to simulation semantic distances, a minority of the associative pairs that are close semantic neighbors are found to be responsible for this correlation. This result suggests that most associative information is not carried by temporal word sequence in language. This methodology is found to be useful in separating typical "associative" stimuli into pure-associative and semantic-associative subsets. The notion that associativity can be characterized by temporal association in language receives little or no support from our corpus analysis and priming experiments. The extent that "word associations" can be characterized by temporal association seems to be more a function of semantic neighborhood which is a reflection of semantic similarity in HAL's vector representations.

We present a model of semantic memory that utilizes a high-dimensional semantic space constructed from a co-occurrence matrix. This matrix was formed by analyzing a 160 million word corpus. Word vectors were then obtained by extracting rows and columns of this matrix. These vectors were subjected to multidimensional scaling. Words were found to cluster semantically, suggesting that interword distance may be interpretable as a measure of semantic similarity. In attempting to replicate with our simulation the semantic and associative priming experiment by Shelton and Martin (1992), we found that semantic similarity plays a larger role in priming than what they would suggest. Vectors were formed for three different types of related words that may more orthogonally control for association and similarity, and interpair distances were computed for both related and unrelated prime-target pairs. A priming effect was found for pairs that were only semantically related, as well as for word pairs that were both semantically and associatively related. No priming was found for word pairs which were strictly associatively related (no semantic overlap). This finding was replicated in a single-word priming experiment using a lexical decision procedure with human subjects. The lack of associative priming is discussed in relation to prior experiments that have found robust associative priming. W e conclude that our priming results are driven by semantic overlap rather than by associativity, and that prior results finding associative priming are due, at least in part, to semantic overlap within the associated word pairs.

We implement a constraint satisfaction connectionist style model that accounts for data from three psycholinguistics experiments investigating the gardenpaih effect with reduced relative constructions. Normative data was collected on the stimuli used in experiments by Burgess and Tanenhaus (1992) and Ferreira and Clifton (1986) and this data served as the input for the simulation. W e have demonstrated with this set of simulations that a plausible theoretical framework for a range of these results is a hierarchical connectionist network which is sensitive to a number of constraints inherent in the input stimuli. The model accounts for the top-down effect of context, the contribution of the bottom-up morphological frequency asymmetry of the verb, and the probabilistic nature of the disambiguating preposition. These effects are sensitive to the timecourse of processing as well. The pattern of results from the psycholinguistic data suggest that syntactic processing is a confluence of multiple constraints that represent both bouomup and top-down influences in processing. These results are incompatible with a deterministic parsing model. The hierarchical connectionist style model presented in this paper is sensitive to the range of constraints discussed above and is offered as a more adaptive theoretical model that can capture the domain of effects found in the literature encompassing local syntactic ambiguity resolution.

Describes a computational model of high-dimensional context space: the Hyperspace Analog to Language (HAL). Shows that HAL provides sufficient information to make semantic, grammatical, and abstract distinctions. Demonstrates the cognitive compatibility of the representations with human processing; and introduces a new methodology that extracts conceptual intersections from the high-dimensional context space. (SR)

Presents a model of high-dimensional context space, the Hyperspace Analogue to Language (HAL), with a series of simulations modelling human empirical results. Proposes that HAL's context space can be used to provide a basic categorization of semantic and grammatical concepts; model certain aspects of morphological ambiguity in verbs; and provide an account of semantic context effects in syntactic processing. (77 references) (Author/CK)

A study was done on the cyclization reactions of molybdenum and chromium carbene complexes with 1,6 and 1,7 enynes. It was shown that the reactions of the enynes with pentacarbonyl(butylmethoxycarbene)molybdenum produce vinylcyclopropanes while reactions with chromium carbene complexes produce a lesser yield of vinylcylclopropanes. Other pathways also form different products.

Systolic (SP), diastolic (DP), and mean arterial blood pressures (MAP) and pulse rate (PR) were recorded on treated and untreated conscious cynomolgus monkeys by the oscillometric method (Dinamap 1846SX/P). Each monkey was placed in a restraining tube with the cuff placed on the base on the shaved tail. Measurements were taken on untreated animals once or twice a day for 4 weeks. The mean and standard deviations for SP, DP, MAP, and PR were approximately 121 ± 17, 60 ± 14, and 84 ± 17 mm Hg and 193 ± 18 pulses/min, respectively. One male and one female cynomolgus monkey were treated with isoproterenol, norepinephrine, and nitropmsside. Blood pressure was measured indirectly with the cuff on the tail and directly with an indwelling catheter in the descending thoracic aorta. Although the oscillometric method was not as sensitive as the catheter, the oscillometric method detected a change in the same direction of SP, DP, MAP, and PR compared with the direct method for all drugs administered. The monitor was reliable and sufficiently accurate to conclude that it may be useful in toxicology studies for evaluation of blood pressure parameters in Conscious Cynomolgus monkeys. [ABSTRACT FROM PUBLISHER]

Immobilization of proteins and other biological macromolecules on solid supports is a method suitable for purification or screening applications in life science research. Prolinx, Inc. has developed a novel chemical affinity system that can be used for specific immobilization of proteins and other macromolecules via interaction of two small synthetic molecules, phenyldiboronic acid (PDBA) and salicylhydroxamic acid (SHA). This report describes immobilization applications of activated microporous membranes that have been functionalized with SHA derivatives. These SHA-membranes exhibit high capacity and specificity for binding of PDBA-labeled nucleic acids and proteins. Conjugation of active protein with PDBA is performed in solution independent of the immobilization step on SHA membranes. The resulting PDBA-protein conjugate is immobilized directly without purification and retains biological activity. PDBA conjugates may also be released from these SHA-affinity membranes in a controlled manner. Capture and release of PBA-modified oligonucleotides is also demonstrated. SHA-membranes can be used as surfaces for microarrays, and are therefore compatible with high-throughput analyses. These properties make them useful for development of numerous preparative or screening applications.