Previous Items Research Articles

Resource Management in the Orb‐Weaving Spider Zygiella x‐notata: I. Influence of Spider Behaviour and Available Prey

AbstractManagement of resource exploitation by the orb‐weaving spider Zygiella x‐notata was investigated in relation to available prey. Prey capture is studied according to prey type (cricket or fly), and the spider's behaviour (waiting without prey or consuming other prey), at the moment when a prey item was placed onto the web. Characteristics of the spider's exploitation of the previous item (feeding time, and quantities ingested) were analysed according to the type and quantity of prey presented, (1 or 2 items at 1‐h intervals). Capture time did not vary in relation to prey type, nor spider activity. However, duration and quantities of certain behavioural components (biting and wrapping) did vary according to prey type and the spider's behaviour, at the moment of presentation of prey. Whatever the type of prey received, if the first item consumed was a cricket, the spiders reduced time spent feeding on this prey without any decrease in the quantities ingested.

COMPUTER COST ESTIMATOR FOR LANDSCAPE INSTALLATION

Cost estimating and job bidding are among the most complex and time-consuming tasks of landscape professionals. A software package was developed to make cost estimating more accurate and efficient. HORT LAND, computer cost estimator for landscape installation, was developed for IBM compatible PC's using SuperCalc 5 spreadsheet software. The user builds a series of data bases, including an items listing of materials and equipment utilized in his operation along with their associated cost. Then, he defines a series of generic tasks, such as planting a 1-gallon size plant, and refers to the previous items list and associated code numbers for the materials and equipment necessary to install the plant. Once these initial data bases are constructed and saved, the user inputs a plant list, including size and price, then instructs the computer to translate the appropriate data from the initial data bases to arrive at a detailed listing of costs. The program then computes direct job cost and bid price, including overhead and profit.

Editorial

This issue of Animal Welfare, which also includes the Index to Volume I, successfully completes the first year of our new journal. The layout is largely as before; there are the usual five scrutinized articles and for the first time a short factual communication. There are reports and comments on matters of animal welfare interest and an extended book and video review section, as well as some relevant reaction to previous items in the letters section. This pattern fulfils our aim of publishing a thought provoking and widely based informative quarterly journal dedicated to highlighting the animal welfare implications of scientific and technical investigations and studies.

Effects of Rehearsal Instructions on the Primacy Effect in Free Recall

The effects of rehearsal on the primacy effect in the serial position curve were investigated. Subjects were instructed to either rehearse or not rehearse previous list items presented at the rate of 1 word/0.5 sec., 1 word/sec., and 1 word/2 sec. The differential rehearsal hypothesis predicted that primacy effects would be observed only in the rehearsal condition. An alternative explanation of the primacy effect in terms of the 1933 von Restorff effect and rehearsal predicted a primacy effect in both the rehearsal and nonrehearsal conditions, with a larger primacy effect in the former. Primacy effects were observed in all conditions but were not significantly larger in the rehearsal condition. The results supported the explanation which included the von Restorff effect.

Modalities of Feeding Behaviour in an Orb-Weaving Spider Zygiella X-Notata (Clerck) (Araneae: Araneidae)

Prey capture and ingestion by the orb-weaving spider Zygiella x-notata have been studied in relation to prey type and to prey density (number of prey items presented/time unit). Whatever the type or the weight of a prey item (11 mg fly, 11 mg or 15 mg cricket larva), the pattern of prey capture did not vary. Ingestion rate did not vary during a meal when the prey was a fly, but this rate decreased with time when the prey was a cricket larva. This decrease was not due to satiation. When several prey items of the same type were placed simultaneously on a web, the spiders subdued them all, chose one of them (generally the first item) and then returned to its retreat to ingest it. A spider presented 3 crickets larvae at one-hour intervals, interrupted feeding on the first item when the second prey was presented. The second item was subdued more rapidly than the first one had been, but the spider left the second prey in the web and returned to its previous item. The third prey item was treated in the same manner as the second one. Spiders spent less time feeding on the first cricket larva in multi-prey tests, whatever the interval between prey arrivals, than on a cricket larva in single-prey test. On the other hand, no difference was found between the single-prey test and the multi-prey test when the prey were flies. In addition, whatever the prey type, quantities ingested (fresh weight) did not vary significantly between the single and multi-prey tests. Data presented here suggest that Zygiella x-notata can modify trade-offs obtained during prey item ingestion and that ingestion curves are good predictions of the quantity ingested in relation of time spent feeding.

Implicit associative responses influence encoding in memory

In list-learning experiments, the orienting question asked of one item may influence the processing of, and memory for, later items in the list. Four experiments demonstrated that words that are not related to their own orienting question, but that are semantically related to the question asked of a previous item, are better recalled than are words that are not related to any question in the list. Factors that influence this memory enhancement include the number of times relevant orienting questions appear during study, as well as the retention interval. Experiment 4 revealed that this effect is contingent upon conscious awareness: Item-category relations do not enhance recall if the subject is not aware of them. The results of the four experiments imply that semantic categories can be primed as implicit associative responses to words, which influence memory.

Effects of Inspection Errors on Dorfman Screening Procedures with Random Group-Size: A Note on Kemp and Kemp's ‘Simple Inspection Scheme for Two Types of Defect’

Kemp and Kemp have proposed a scheme of inspection for two types (A and B) of non-conformity. There is serial inspection for type A, continuing until a sequence of k successive As is observed. These k items are discarded, and all previous items (since the last inspection for A) are subject to a Dorfman group-screening inspection procedure for B. We develop formulae for the properties of this scheme, when inspection (for both A and B) may not be perfect, allowing for both false negatives and false positives. Some numerical values given by the formulae are presented, with a view to assessing the robustness of Kemp and Kemp's scheme.

The effects of constrained rehearsal on judgments of temporal order

Tzeng and Cotton’s (1980) study-phase retrieval model holds that temporal encoding of words is acquired through the establishment of contextual associations among list items. Such associations are strengthened by a subject’s ability to rehearse previous items, that is, to engage in displaced rehearsals. Since displaced rehearsals are critical in the study-phase model, to place constraints on such rehearsals should alter performance for the memory of temporal order. Five different rehearsal strategies were employed within a distractor paradigm to test this prediction. Two distinct instructional sets were also administered, with one half of the subjects instructed that serial order information was important, while the remaining subjects were told only that a free recall test would be given. Differences were found for serial position scores among the different rehearsal strategies in support of the study-phase retrieval model. Informed and uninformed instructional groups did not differ in temporal memory.

The role of memory in attenuations of the suffix effect.

Various properties attenuate the auditory suffix effect. These properties may improve recall by allowing the suffix to be excluded from the auditory store (or stores) used for immediate ordered recall, or they may improve recall even though the suffix is included in the auditory store. Nine items were presented, with the last item being either a suffix or another item to be recalled. In Experiment 1, the impairment in recall of the previous items produced by presenting a to-be-recalled last item in a different voice was the same as the impairment produced by presenting a suffix in a different voice. The same result was found in Experiment 2 for presenting the last item in a different spatial location and in Experiment 3 for delaying the presentation of the last item. Apparently the attenuating properties improve recall through memorial factors, and not by allowing the suffix to be excluded from the auditory store.

A Provincial Bibliography on Names in the Works of Shakespeare

A Provincial Bibliography on Names in the Works of Shakespeare

The process of responding to personality items: Inconsistent responses to repeated presentation of identical items

A promising approach to understanding the processes involved when subjects respond to personality items is provided by the investigation of the causes of inconsistent responses when subjects answer the same item on two occasions. Among these causes are the properties of the item. Previous item research focused almost exclusively on properties which are not highly specific to the item, such as endorsement rate (ER) and social desirability scale value (SDSV). Although past studies found that items with ‘extreme’ SDSVs and/or ERs elicit fewer inconsistencies, these studies ignored more item-specific properties such as item content and item ambiguity. The present study demonstrates that contrary results regarding consistency may be obtained when more item-specific properties are taken into consideration. These results are interpreted as evidence that certain kinds of item content can increase the indecision and conflict that characterize some subjects' response processes.

The Africa Bibliographic Centre in Dar es Salaam: Its Origins and Immediate Plans

The Africa Bibliographic Centre Secretariat, or ABCS, is based in Dar es Salaam, Tanzania. (it has no connection with the African Bibliographic Centre in Washington D.C., which is run by Daniel Matthews primarily as an information centre for American users.) The function of the ABCS is, for the time being, limited to propagandising the “ABC concept” through the medium of the ABC Newsletter, which is currently distributed gratis to a wide range of institutions and individuals within Africa and to a much smaller number outside. Although some previous news items in the professional literature have discussed the ABC's function and role, the following statement may be taken as reflecting the current situation.

The role of response confusion in proactive interference

In two experiments using the Brown-Peterson memory paradigm, various instructions to guess had small effects on recall, but sizeable effects on the incidence of prior list intrusions. Subjective confidence ratings indicated that prior list intrusions were generally known to be incorrect. In Experiment III, 24 subjects, who were required to recall items from the present and immediately preceding trial on each of 16 trials, recalled present trial items at the same level as subjects under normal conditions. Correlation analyses, intrusion analyses, and confidence rating analyses indicated no relation between recall of present and previous trial items. These results indicate that proactive interference is primarily the result of inability to generate correct items, rather than confusion between present and previous items.

Genetics and Morphometrics of Cerion at Pongo Carpet: A New Systematic Approach to this Enigmatic Land Snail

Gould, S. J., D. S. Woodruff, and J. P. Martin (Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts 02138; and Department of Zoology, Duke University, Durham, North Carolina 27708) 1975. Genetics and morphometrics of Cerion at Pongo Carpet: a new systematic approach to this enigmatic land snail. Syst. Zool. 23:518-535.Cerion displays an extraordinary range of phenetic diversity. This has led to the naming of several hundred species, though only a mere fraction of these are valid if, as we believe, morphological diversity does not reflect reproductive isolation in this genus. The taxonomic morass has precluded fruitful evolutionary study of these extremely plastic animals. We apply techniques of multivariate morphometrics and biochemical genetics to a local situation on the northeastern coast of Great Abaco, Bahamas. Here, a local population is semi-isolated along a strip of coastline near the settlement of Pongo Carpet; it is in contact with other populations only to the north. Its morphology is highly distinct and, on all previous criteria, it merits recognition as a separate species. We find, however, that its patterns of covariation (as revealed by factor analysis) cannot be distinguished from those of the only recognized taxon of northern Abaco, C. bendalli (while patterns in the southern Abaconian species, C. abacoense, are entirely different). Canonical analysis displays a cline towards standard morphology from the region of maximum isolation at Pongo Carpet to the northern area of potential contact with standard C. bendalli. Levels of morphological variation do not differ among samples; those of intermediate morphology show no increase in variability or other signs of hybridization. Starch-gel electrophoresis showed the pongo carpet samples to be genetically indistinguishable from standard bendalli at the 18 structural gene loci surveyed. No evidence for selfing or inbreeding was detected. The proportion of polymorphic loci in each population ranged between 16.6-22.2%; genic heterozygosity per individual was 5.25-6.79%. The only genetic anomaly within the area contrasts some standard and pongo carpet samples with C. bendalli from elsewhere on Abaco and Grand Bahama Island. We conclude that the pongo carpet population is a well-marked geographic variant within Cerion bendalli. The coordinated application of biochemical genetics and multivariate morphometrics can resolve many issues in the systematics of highly variable organisms. [Geographic variation; Cerion; morphometrics.] Cerion is a classic among evolutionary classics for its supposed protean speciation. Clench (1957) lists 302 recorded from the Bahama islands alone. Whether the plethora of specific names be justified or not, we may safely state that phenetic diversity within the genus can only be described as fantastic (Fig. 1). Moreover, variation within any local population is strictly average in extent; thus, local popu1 This is the third in a series of papers on The Natural History of Cerion. Previous items are Gould (1969a and 1971). 2 Department of Zoology, Duke University, Durham, North Carolina 27708. lations are strongly marked, and demes in close geographic proximity can be very different in mean morphologies. How can we deal with such a genus in a modern way? The old practice of erecting a name for each local variant does not, in all likelihood, reflect the biology of reproductive isolation. Yet this procedure has colored all previous approaches to Cerion. For example, the standard hypothesis (Clench, 1957; Mayr and Rosen, 1956) that of Cerion are haphazardly distributed by vagaries of hurricane transport depends upon the general validity of current specific nomenclature. If the species

Retrieval cues and release from proactive inhibition

The present experiment attempted to specify the locus and nature of the “release from PI” phenomenon. On the critical trial, the material to be remembered (word triads) shifted from one subset of a larger category to another subset. No release was found when subjects were provided with the general category name as a retrieval cue, but release was obtained when the appropriate subset name was given as a cue at presentation. A similar release effect was obtained when the subset cue was presented at retrieval. The results favor a retrieval explanation of the release phenomenon although it is unclear whether cues increase accessibility to the TBR material or, rather, help to discriminate current from previous items.

Invariance of forgetting rate with number of repetitions in verbal short-term recognition memory

Ss listened to a list of eight different three-digit numbers, presented at the rate of one three-digit number per second. In many of the lists, one of the three-digit numbers was repeated three times in immediate succession (in a 3-sec period) before going on to the next number. At the end of the list of eight different three-digit numbers, one three-digit number was presented as a recognition test item. The test item could have appeared at any of the eight serial positions or be a new item. Ss were instructed to rehearse only the current item in the list, not previous items. Under these conditions, repetition of an item led to greater degree of learning in short-term memory, but the forgetting rate appeared to be invariant with number of repetitions.

A Comparison of Computer-Simulated Conventional and Branching Tests

Abstract : In the usual testing situation, each examinee takes all the items, and item sequence is the same for each examinee. It is possible, however, to have sequential or branching tests in which all examinees do not take te same items and the sequence of item presentation for an individual is some function of his performance on previous items; that is, an item answered correctly is followed by a more difficult item, an item answer incorrectly, by a less difficult item. The rationale for the latter procedure is that presentation of items based on an examinee's past performance allows each individual to take items that are progressively more appropriate to his own level of ability. It is conceivable that such a procedure would reduce testing time, and for a given amount of time would permit more accurate measurement of an individual's ability, principally by reducing opportunities for chance success by low ability examinees' attempting items too difficult for them.

A perceptual isolation effect in short-term memory

Perceptually isolating a CCC by enclosing it in a rectangle improved STM for that item. No residual effects of this isolation were found on following nonisolated items. The possibility of accounting for improved STM of items involving conceptual class change in terms of enhancement through isolation, instead of reduction of semantic interference effects of previous items, was discussed.

Time, interference, and rate of presentation in short-term recognition memory for items

A list of 9 or 15 letters was presented at a rate of 1, 2, or 4 letters per second, followed by a test letter, followed by the subject's decision as to whether the test letter appeared in the previous list. The decay of trace strength was a simple exponential decay function of delay. However, the rate of decay was not constant for different rates of presentation, whether delay was measured in time or intervening items. Rather, time decay rate increased approximately linearly with presentation rate, but with a positive intercept, not a zero intercept as required by the hypothesis that delay is measured in intervening items. Decay rate for previous items appears to be greater during the time (less than 0.25 sec.) for acquisition of an item than during the time between acquisition of adjacent items.

The anterior subdivision block of the left bundle branch of his: 1. The ventricular activation process

After the interruption of the anterior subdivision of the left bundle branch, the following are the fundamental electrophysiologic changes: 1. The activation is delayed at the upper third of the left septal mass as well as at the high anterolateral regions of the free left ventricular wall. 2. The initial septal vector, due to the activation of the middle third of the interventricular septum, remains unchanged after blocking the anterior subdivision of the left bundle branch in two thirds of the cases, and it increases in voltage in the remaining third. 3. As a consequence of item 2, it can be stated that the left anterior subdivision is not the route for the stimulus which depolarizes the middle third of the interventricular septum. 4. As a consequence of the previous item the stimulus which activates the middle third of the interventricular septum arrives through the posterior subdivision of the left bundle branch. 5. RBBB superimposed on the interruption of the anterior subdivision, does not produce any further delay in the activation of the left ventricle. 6. The experiemtnal association of RBBB with interruption of the anterior subdivision of the left bundle branch can be found without any degree of A-V block. 7. The block of the anterior subdivision, isolated or combined with RBBB, causes characteristic electrocardiographic changes that permit its recognition under experimental as well as in clinical conditions.