Systems approach to the concept of niche

Conclusion The systems approach to niche presented herein stands as an example of the unifying potential of mathematical system theory when applied to concepts and principles of ecology. Beginning with subjective concepts from the naturalistic tradition, the niche was framed in the formalism of general system theory. So modeled, it appeared as a restriction of a more general construct, the environ. Both niches and environs are implementable in the context of ecosystem models, and with the growing ability of ecologists to construct such models, system theoretic niches and environs both should serve in the future to clarify old problems of ecology, and make it possible to raise new classes of problems. The nature of niches, always difficult conceptually for the ecologist, may now give way to further development, both theoretical and empirical.     

Equationally definable implication algebras for orthomodular lattices

The fact that it is possible to define three different material conditionals in orthomodular lattices suggests that there exist three different orthomodular logics whose conditionals are material conditionals and whose models are orthomodular lattices. The purpose of this paper is to provide equationally definable implication algebras for each of these material conditionals.     

Representation of inflected nouns in the internal lexicon

The lexical representation of Serbo-Croatian nouns was investigated in a lexical decision task. Because Serbo-Croatian nouns are declined, a noun may appear in one of several grammatical cases distinguished by the inflectional morpheme affixed to the base form. The grammatical cases occur with different frequencies, although some are visually and phonetically identical. When the frequencies of identical forms are compounded, the ordering of frequencies is not the same for masculine and feminine genders. These two genders are distinguished further by the fact that the base form for masculine nouns is an actual grammatical case, the nominative singular, whereas the base form for feminine nouns is an abstraction in that it cannot stand alone as an independent word. Exploiting these characteristics of the Serbo-Croatian language, we contrasted three views of how a noun is represented: (1) the independent-entries hypothesis, which assumes an independent representation for each grammatical case, reflecting its frequency of occurrence; (2) the derivational hypothesis, which assumes that only the base morpheme is stored, with the individual cases derived from separately stored inflectional morphemes and rules for combination; and (3) the satellite-entries hypothesis, which assumes that all cases are individually represented, with the nominative singular functioning as the nucleus and the embodiment of the noun’s frequency and around which the other cases cluster uniformly. The evidence strongly favors the satellite-entries hypothesis.     

Accessibility of the voicing distinction for learning phonological rules

In three experiments a series of nonsense syllables ending in consonants was presented to adult subjects who had to discover or learn a rule classifying the syllables into two groups. The rule was based either on the voicing of the final consonants or on an arbitrary division of them. Subjects performed better with the voicing than with the arbitrary rule only when there was a straightforward relationship between the voicing rule and the plural formation rule in English or, more generally, when voicing assimilation with an added consonant was involved and attention was focused on the sound and articulation of the syllables. We conclude that the voicing distinction is not ordinarily accessible and that individuals easily learn and use phonological rules involving voicing assimilation because of articulatory constraints on the production of consonant clusters.     

Auditory processing of brain-damaged adults under competitive listening conditions

Right CVAs, mild left CVAs, and non-brain-damaged adults received the Token Test under three conditions: quiet, white noise, and speech babble. Left CVAs performed most poorly of all groups in all conditions experiencing difficulty with subtests III, IV, and V. Right CVAs were inferior to controls on each of these three subtests in the speech babble condition only. Thus, right CVA difficulty with both memory and syntactic tasks was demonstrated in speech babble. These results are explained by the hypothesis that both hemispheres are necessary to process auditory information under complex listening conditions. Total brain capacity of right CVA patients may be overloaded if either memory load or linguistic complexity is increased in the presence of certain types of listening competition.     

The communication disorder in dialysis dementia: A case report

The communication disorder in dialysis dementia is an integral feature of the syndrome. This report describes the communication disorder in a 67-year-old man over a period of 4 months from his admission to the hospital to his death. In the early stage of the syndrome, the most prominent feature was a speech problem, the characteristics of which may vary among cases. In the middle stage, it was difficult to distinguish among aphemia, aphasia, or a combination of dysarthria and confusional state. The severity of the problems in these stages was temporally related to the dialysis treatments. The final stage was characterized by constant mutism and was unrelated to the dialysis treatments. Death occurred 10 months after the communication problems emerged. Communication studies of dialysis dementia patients may offer a systematic method to monitor the course of the syndrome, its response to therapeutic trials, and a clinical model for the study of communication disorders in general.     

Word-finding as a function of stimulus context: Children compared with aphasic adults

A study of object naming in 202 children, aged 5–11 years, demonstrated that varying the stimulus context affected the level of response accuracy. From age 6 to 10, completing a sentence with a noun (auditory) yielded the lowest error scores, naming objects upon hearing a definition (also auditory) produced most errors, while responding with names to pictured objects was of intermediate difficulty. This is the same order of object naming difficulty found in adult aphasic patients. Children older than 10 do not appear to be affected by stimulus context in their object naming. Results are discussed in terms of the relative syntactic difficulty of the two auditory conditions, the unexpected sex differences, and the “aphaseoid” naming errors of children.     

Individual and organizational correlates of promotion refusal

Individual and organizational correlates of employees who refuse seniority-based promotions in union lines of progression are examined. The sample consisted of 313 production employees of a large manufacturing complex. Correlational and discriminant analyses revealed that age, being female, and number of employees in the department related positively to promotion refusal, while years of education and pay showed a negative relationship. Of these variables, years of education was the strongest predictor. Potential explanations for the results relate to stress avoidance, perceived inabilities, and equity theory. Areas for future research are suggested.     

Treatment of urinary urgency and excessive frequency: a case study

A 39-year-old male presenting with a 5 year history of excessive urinary frequency and urgency was treated first with scheduling of urination, use of external urinary catheter and progressive muscular relaxation and then with a urinary retention training procedure. After the first set of procedures, urinary frequency decreased, whereas urgency increased slightly. After completion of retention training, both symptoms were alleviated. Overall, urinary frequency decreased from a baseline average of 14 urinations daily to a post-treatment average of 6.5 urinations per day. Urinary urgency decreased from a baseline average of 35 urges per day to a post-treatment average of 9.3 urges per day. Gains were maintained at 3 and 5 month follow-up.     

Measurement of sexual arousal in several paraphilias: The effects of stimulus modality,instructional set and stimulus content on the objective

The effects of instructional set (become aroused or suppress arousal), stimulus modality (videotape, audiotape, slides, free fantasy) and stimulus content (paraphilic or non-paraphilic) on sexual arousal, as measured by penile plethysmograph, of six different groups of paraphilics, pedophiles, rapists, exhibitionists, homosexuals, sado-masochists and fetishists, were determined. The results showed significant main effects of instructional set and of stimulus modality (videotape was clearly more arousing) as well as several complex interactions of diagnostic group with the other independent variables.