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PubMed1996

[Effect of weight of feature and frequency on recognition of butterfly patterns].

Three experiments are reported which deal with the nature of categorization of natural objects. Stimulus materials were schematic butterfly patterns. Systematic transformations were given to the original pattern to make stimulus instance. In Experiment 1, subjects were given a recognition memory task with recognition ratings. Recognition ratings were found to be related to family resemblance score (FRS: the sum of feature frequency in the category) rather than to transformation or subjective similarity to the original. In Experiment 2, subjects were given the recognition memory task while the FRS was kept constant. Weight of each feature affected recognition ratings differently, when FRS was kept constant. In Experiment 3, subjects were given the same task as in Experiment 2 while the FRS and the component frequency of each feature were kept constant. Again each feature affected recognition ratings differently. These findings suggest that both the frequency and weight of feature itself affect recognition ratings.

Adult↗
PubMed1968

Effect of cell moisture on the thermal inactivation rate of bacterial spores.

Thermal inactivation rates were determined for two strains of Bacillus subtilis var. niger spores after equilibration to various relative humidity (RH) levels. In these tests, small thin stainless-steel squares were each inoculated with a drop of spore suspension and equilibrated to 11, 33, or 85% RH. Following equilibration, the squares were placed on a hot plate preheated to 108, 125, 136, 164, or 192 C for various exposure times and then assayed for surviving organisms. The results revealed that spores of the A strain of B. subtilis were least resistant if preequilibrated to 11% RH and most resistant if preequilibrated to 85% RH. The same trend was obtained at all temperatures except 192 C, at which, no difference was noted, probably because the rapid kill time approaches the heat-up time of the stainless-steel square. The B strain of B. subtilis spores showed an opposite RH effect; that is, the cells preequilibrated to 11% RH were the most resistant. Because the two strains of spores were grown on different media, further studies were conducted at 136 C after subculturing the cells on different media. When the B strain was subcultured on the A strain medium, the pattern was reversed; the cells preequilibrated to low RH were then least resistant. Although it was not possible to reverse these cells to the original pattern by subculturing on the original B strain medium again, the pattern was altered to the point that there was no significant difference in heat resistance of these cells regardless of the preequilibration RH. The same result was obtained when the A strain was grown on the B strain medium; that is, the thermal resistance could not be reversed, but it was altered from the point where the low RH equilibrated cells were least resistant initially to the point where there was no significant difference in any of the cells regardless of what RH was used for preequilibration. The thermal resistance of spores seemed to be dependent on (i) the medium on which the spores are grown, (ii) the RH on which they are exposed before heating, and (iii) some genetic characteristic of the cell.

Bacillus subtilis↗
PubMed1994

External four-channel tocography during delivery.

OBJECTIVE: A four-channel tocographic technique was developed in order to improve present knowledge of spatial uterine motility. METHOD: Fifty-four women were monitored during labor. Four pressure transducers were attached in a square around the umbilicus. RESULTS: The origin of uterine contractions was generally determined to be in the upper right segment of the uterus. The rate of operative deliveries was decreased in the case of predominant upper right origin of labor. Most of the contractions with clear propagation patterns originated on the upper right side, continued to the left and then spread to the lower right part of the uterus. The highest relative intensity was also measured on the upper right side. CONCLUSION: Predominant upper right origin of labor may be important for unassisted or spontaneous delivery.

Adult↗
PubMed1991

Individuality of DNA denaturation patterns in human sperm as measured by the sperm chromatin structure assay.

Eight monthly semen samples from 45 men not known to be exposed to industrial toxicants were measured by the flow cytometric sperm chromatin structure assay (SCSA). This assay determines susceptibility of sperm DNA to in situ, acid-induced denaturation and is quantitated by the metachromatic shift of acridine orange fluorescence from green (native DNA) to red (denatured DNA). The observed green versus red fluorescence scattergram (cytogram) patterns were generally unique between donors and homogeneous within a donor over time. Within a donor, the cytogram patterns were the same whether intact sperm cells or detached nuclei were measured. For some individuals the cytogram patterns differed for some months and then returned to the original pattern. Intraclass correlations for mean and standard deviation of alpha t [alpha t = red/(red + green) fluorescence] were higher (.67 to .90) than any classically measured semen variables, suggesting that SCSA results within an individual were more consistent than other measures. Furthermore, average within-donor CV of alpha t parameters expressed as a percent of any given individual's means was around 10%, which is significantly lower than those derived from common semen measures. The SCSA is an objective, technically sound, biologically stable, sensitive, and feasible measure of semen quality.

Chromatin↗
PubMed1989

Memory and age differences in spatial manipulation ability.

Young and old adults were asked, in 3 experiments, to make decisions about the identity of line segment patterns after either adding or subtracting line segments from the original pattern. On some of the trials, the line segments from the initial display were presented again in the second display to minimize the necessity of remembering early information during the processing of later information. Although this manipulation presumably reduced the importance of memory in the tasks, it had little effect on the magnitude of the age differences in any of the experiments. Because the 2 groups were equivalent in accuracy of simple recognition judgments, but older adults were less accurate when the same types of decisions were required in the context of an ongoing task, the results suggested that older adults may be impaired in the ability to retain information while simultaneously processing the same or other information.

Adolescent↗
PubMedDate not supplied

[Significance of the site of uterine contraction for labor progress and duration of pregnancy].

A four-channel topographic technique was developed in order to improve information about spatial uterine motility. 54 women were monitored during delivery. Four pressure transducers were attached in a square around the umbilicus. Most frequently the origin of labour could be determined in the upper right segment of the uterus. The rate of operative deliveries was decreased in case of predominant upper right origin of labour. The majority of contractions with clear propagation patterns originated at the upper right site, continued to the left and then to the lower right part of the uterus. The highest relative intensity was also measured at the upper right site. Predominant upper right origin of labour may be important for undisturbed delivery. The probability of a preterm delivery is increased in case of an upper right origin of labour.

Adult↗
PubMed1996

A comparative evaluation of the in vitro penetration performance of the improved Crest complete toothbrush versus the Current Crest complete toothbrush, the Colgate Precision toothbrush and the Oral-B P40 toothbrush.

Removal of plaque and debris from interproximal surfaces during toothbrushing has generally been difficult to achieve, in large part because traditional flat-bristled toothbrushes do not offer good interproximal penetration. As a result, a number of varying bristle designs have been developed, with the rippled-design brush shown to be particularly effective at removing interproximal plaque. Recently, an existing brush, the original Crest Complete, was modified to offer a more deeply rippled version. This study evaluated the interproximal penetration of four bristle designs: rippled pattern (original Crest Complete), deeper rippled pattern (improved Crest Complete), multi-level (Colgate Precision), and flat-tufted (Oral-B P40). The study used a previously reported in vitro model for determining interproximal penetration of manual toothbrushes (J Clin Dent 5:27-33, 1994). In order to effectively mimic the in-use characteristics of toothbrushing, this model is based on analysis of videotaped consumer brushing habits, tooth morphology, and in vivo plaque tenacity characteristics and uses the three most predominantly used brushing techniques (circular, up-and-down, and back-and-forth, with the brush held at both 45 and 90 degrees to the tooth surface). In addition, the model's brush stroke length, brush force, and brush speed are likewise based on analysis of consumer brushing patterns. The results of the study indicate that the new Crest Complete with deeper rippled bristles provided significantly superior (p < or = 0.05) interproximal penetration than the Colgate Precision and Oral-B brushes overall and for three of the four brush strokes tested. In addition, the new Crest Complete was found to provide significantly superior interproximal penetration to the original Crest Complete overall and in circular and up-and-down strokes, and the original Crest Complete provided superior overall interproximal penetration to the Colgate and Oral-B brushes.

Analysis of Variance↗
PubMed1995

Is transposed skin transformed in major head and neck mucosal reconstruction?

We used histological and histochemical methods to investigate the possible changes with time in skin transposed into the oropharynx and oral cavity of patients whose surgical wounds were reconstructed with the classic pectoralis major flap. We found histological evidence that skin morphology was maintained (keratinization with reduced, but the desquamating layer, hair follicles, sweat and sebaceous glands were identifiable), and noted an intense inflammatory reaction in the dermis. Histochemical studies confirmed the progressive flattening of the basal interdigitations between the epithelium and dermis, and the gradual reconstruction of the basement membrane. Although skin-mucosa continuity developed fairly quickly without scar reactions, the two epithelia maintained their original patterns of keratin production, i.e., their textural peculiarities. We propose an original method for the transposition of muscular flaps implanted with autologous culture of keratinocytes, an approach developed in an attempt to ensure more satisfactory rehabilitation of the removed mucosal structures.

Carcinoma↗
PubMed1989

On the visual orientation of random dot Moiré patterns.

We studied the orientation perception of dot patterns with Moiré effect. The Moiré effect was achieved by rotating the original patterns over small angles. When the angle was increased the effect disappeared while the characteristics of orientation estimation remained unchanged. For relatively small angles the subjects performance can be described by a model based on the concept of least squared distance axis. For large angles of rotation this model has began to be insufficient and a more refined model is proposed here.

Adult↗
PubMed1995

Spatial organization of transport domains and subdomain formation in the plasma membrane of Chara corallina.

Pattern formation mechanisms in developing organisms determine cellular differentiation and function. However, the components that interact during the manifestation of a spatial pattern are in general unknown. Characean algae represent a model system to study pattern formation. These algae develop alternating acid and alkaline transport domains that influence the pattern of growth. In the present study, it will be demonstrated that a diffusion mechanism is implicated in acid and alkaline domain formation and this growth pattern. Experiments on the characean growth pattern were performed that resulted in pronounced, however, unpredictable modifications in the original pattern. A major component involved in this pattern-forming mechanism emerged from the nonlinear kinetics of the H(+)-ATPase that is located in the plasma membrane of these algae. Based on these kinetics, a mathematical model was developed and numerically analyzed. As a result, the contribution of a diffusional component to the characean acid/alkaline pattern appeared most likely.

Biological Transport↗
PubMed1989

Instability of integrated hepatitis B virus DNA with inverted repeat structure in a transgenic mouse.

We established four cell lines, from the liver cells of a transgenic mouse, constructed with hepatitis B virus DNA that had an inverted repeat structure. The integrated DNA patterns of the four established cell lines were different from one another and from the original pattern. These data show that the instability of integrated hepatitis B virus DNA would also occur in somatic cells during replication, apart from meiosis, which was previously reported.

Animals↗
PubMed1991

Patterns of DNA methylation in selected human genes in different Hodgkin's lymphoma and leukemia cell lines and in normal human lymphocytes.

The human genome, like many other genomes, harbors highly specific patterns of DNA methylation which have not yet been systematically studied. In a limited investigation on the genes for tumor necrosis factors-alpha and -beta, a surprising interindividual concordance in the patterns of DNA methylation at the nucleotide level has been demonstrated earlier by using the genomic sequencing method on DNA from individuals of very different ethnic origins. Patterns of DNA methylation could perhaps serve as indicators for genetic activities. These activities would not have to be restricted to gene transcription but could relate to other genetic activities in the cell. DNA methylation patterns are known to be cell type-specific. We have now initiated a study of these DNA patterns in human lymphocytes and in human cell lines of different malignant origins. Several of the proto-oncogenes, parts of the genes for tumor necrosis factor-alpha and -beta, the insulin receptor and lamin C have been used as hybridization probes. We have relied to some extent on the documented observation that the methylation patterns at 5'-CCGG-3' (HpaII/MspI) sequences yield a reflection of patterns at all 5'-CG-3' sequences. Three main types of patterns have been observed. Some of the probed segments are completely unmethylated; others are fully methylated, most of the areas are partly methylated exhibiting complex patterns at the 5'-CCGG-3' sites. In different tumor cell lines, different DNA methylation patterns are apparent for the same DNA probes. Comparisons of the methylation patterns in a given DNA segment between DNA from primary normal human lymphocytes and DNA from different tumor cell lines reveal changes in these patterns in several instances.

Base Sequence↗
PubMed1998

Representation of objective similarity among three-dimensional shapes in the monkey.

Humans have been recently shown to represent parameterized three-dimensional objects in a manner that preserves relative similarities (as measured by parameter-space distances) among the objects (Cutzu and Edelman 1996). We show that the representation of objects in the monkey visual system is similarly faithful to the parametric variation built into the stimulus set. A monkey (Macaca fuscata) performed a delayed matching-to-sample task with 28 images (4 views x 7 objects). Stimuli in each of the two experiments were seven computer-rendered parameterized animal-like shapes, arranged in a low-dimensional configuration (namely, a two-dimensional TRIANGLE) in a common 56-dimensional parameter space. The monkey's task was to match objects (not views). Each experiment lasted for 3-4 weeks after the introduction of the stimulus set to the subject. Error rates were entered into a 7 x 7 object confusion matrix and submitted to nonmetric multidimensional scaling (MDS). In both experiment 1 (mean correct rate 69.7%) and experiment 2 (mean correct rate 59.9%), the MDS solutions resembled closely the low-dimensional parameter-space patterns built into the stimuli, in the sense that the point corresponding to the central one in the original pattern was inside the other six points and that the order of the six points in angular positions around the center point was preserved. A simulation study showed that the resemblance could not be due to chance. These results demonstrate the possibility of veridical representation of parametric similarity among complex objects in the monkey.

Animals↗
PubMed1998

Detection of suspected malignant patterns in three-dimensional magnetic resonance breast images.

In this article, a Boolean Neural Network (BNN) is used for the detection of suspected malignant regions in 3D breast magnetic resonance (MR) images. The BNN is characterized by fast learning and classification, guaranteed convergence, and simple, integer weight calculations. The BNN learning algorithm is incremental, which allows the addition and deletion of training patterns without unlearning those already learned. The incremental learning algorithm automatically reduces the training set and trains the network only with those examples estimated to be useful. The architecture is suitable for parallel hardware implementation using available Very Large Scale Integration (VLSI) technology. The BNN was trained by using a set of malignant, benign, and false-positive patterns, extracted by experts, from selected MR studies, by using an incremental learning algorithm. After training, the network was tested by means of a consistency checking test, cross validation techniques, and patterns from actual MR breast images. During the consistency test, the BNN was tested by using the same patterns used for training. The BNN classification accuracy in this case was 99.75%, proving the ability of the BNN to select useful patterns from the training set. Then, a leave one out cross-validation (LOOCV) test was done by using patterns from the training set and the classification accuracy was 90%. Next, an extended training set was created by shifting the original patterns in different directions. A cross-validation test was then performed by dividing the set of patterns into a training and a test set. Classification accuracy was compared to the nearest neighbor classifier. Results showed that the BNN achieved an average of 77% classification accuracy while requiring only 34% of the original training set. On the other hand, the nearest neighbor classifier achieved an accuracy of 57.9% while retaining the whole training set. Another test using actual MR slices different from the training set was done and results compared favorably to a radiologist's findings. Test results show the BNN's capability to detect suspected malignant regions in 3D MR images of the breast. The proposed BNN architecture can save the radiologist a great deal of time browsing MR slices searching for suspected malignancies.

Algorithms↗
PubMed1989

Development of the rat thalamus: IV. The intermediate lobule of the thalamic neuroepithelium, and the time and site of origin and settling pattern of neurons of the ventral nuclear complex.

Short-survival, sequential, and long-survival thymidine radiograms of rat embryos, fetuses, and young pups were analyzed in order to examine the time of origin, settling pattern, migratory route, and site of origin of neurons of the ventral nuclear complex of the thalamus. Quantitative examination of long-survival radiograms established that the bulk of the neurons of the ventral nuclear complex are generated between days E14 and E16 but with statistically significant differences between its three nuclei. The ventrobasal nucleus is the oldest component (97% of the cells are generated on days E14 and E15); the ventrolateral nucleus is next (82% of the cells are generated on days E14 and E15); and the ventromedial nucleus is last (51% of the cells are generated on days E14 and E15). In addition to this caudal-to-rostral (from the ventrobasal nucleus to the ventrolateral nucleus) and lateral-to-medial (from the ventrobasal nucleus to the ventromedial nucleus) internuclear gradients, there are lateral-to-medial and ventral-to-dorsal intranuclear neurogenetic gradients within the ventrobasal and ventrolateral nuclei. Qualitative examination of short and sequential survival thymidine radiograms indicate that the neurons of the ventral nuclear complex originate in the unique intermediate thalamic neuroepithelial lobule, which is distinguished from the rest of the thalamic neuroepithelium by the presence of a mitotically active secondary neuroepithelial matrix. Two sublobules can be distinguished in the intermediate lobule during the early stages of thalamic development. On the basis of their location and chronological pattern of cell production and differentiation, it is inferred that the neurons of the ventrobasal nucleus originate in the earlier differentiating, posteroventrally situated inverted sublobule, and the neurons of the ventrolateral nucleus are produced in the later differentiating, anterodorsally situated everted sublobule. The neurons of the ventromedial nucleus appear to originate from the intermediate neuroepithelial lobule after its two sublobules are no longer distinguishable. The heavily labeled neurons generated soon after injection on day E15 form a wave front that translocates in a lateral direction at a steady rate of 215 microns/day. Examination of methacrylate-embedded materials showed that, in day E15 rats the actively migrating cells are spindle-shaped, with their long axis oriented horizontally. The far-laterally situated differentiating cells (the oldest neurons) become vertically oriented by day E16. Associated with this change in polarity, vertically oriented fibers appear among the cells. These fibers can be traced to the inte

Animals↗
PubMed1993

Restoration of motor unit properties and fiber type distribution in reinnervated axolotl skeletal muscle.

The contractile properties of functionally isolated motor units and the muscle fiber type distribution of reinnervated iliotibialis posterior muscles were examined in axolotls (Ambystoma mexicanum) 7 to 12 months after complete transection of the hind limb nerve trunks. Motor units were continuously distributed with respect to size and contractile speeds and there was a positive correlation between motor unit size and twitch:tetanus ratio. The degree of overlap between motor units was positively correlated with motor unit size and inversely correlated with similarity of contractile speeds. In addition, the muscle fiber type distribution within the reinnervated muscles, as revealed by immunocytochemical localization of tonic, slow, and fast myosin isoforms, was indistinguishable from that in the contralateral unoperated muscles, with no evidence of fiber type grouping. Thus, the motor organization after reinnervation was very similar to that of normal muscles examined previously. The only difference found was that a small number of motor units contracted unusually rapidly in reinnervated muscles. The absence of muscle fiber type redistribution and the essentially normal motor unit characteristics suggest that the original pattern of synaptic connections was reestablished following reinnervation. These observations are consistent with the returning motor neurons selectively reinnervating their original muscle fiber types.

Ambystoma mexicanum↗
PubMed1988

Development of the rat thalamus: II. Time and site of origin and settling pattern of neurons derived from the anterior lobule of the thalamic neuroepithelium.

Short-survival, sequential, and long-survival thymidine radiograms of rat embryos, fetuses, and young pups were analyzed in order to examine the time of origin, settling pattern, and neuroepithelial site of origin of the anterior thalamic nuclei--the lateral dorsal (lateral anterior), anterodorsal, anteroventral and anteromedial nuclei--and of two rostral midline structures--the anterior paraventricular and paratenial nuclei. The neurons of the lateral dorsal nucleus are generated over a 3-day period between days E14-E16 and their settling pattern displays a combined lateral-to-medial and dorsal-to-ventral neurogenetic gradient. The bulk of the neurons of the anteroventral nucleus are generated over a 3-day period between days E15-E17 and settle with an oblique lateral-to-medial and ventral-to-dorsal neurogenetic gradient. The bulk of the neurons of the anteromedial nucleus are generated over a 2-day period between days E16-E17 and show the same settling pattern as the anteroventral nucleus. The neurons of the anterodorsal nucleus are generated over a 3-day period between days E15-E17 and show a lateral-to-medial neurogenetic gradient. The bulk of the neurons of the central part and lateral part of the paraventricular nucleus are generated over a 2-day period (E16-E17 and E17-E18, respectively) and each part displays a ventral-to-dorsal neurogenetic gradient. Finally, the bulk of the neurons of the paratenial nucleus are generated over a 4-day period between days E15-E18 and settle with a lateral-to-medial neurogenetic gradient. Observations are presented that the anterior thalamic nuclei, constituting the distinct "limbic thalamus," derive from a discrete neuroepithelial source. This is the crescent-shaped germinal matrix lining the diencephalic (medial) wall of the hitherto unrecognized anterior transitional promontory, which we call the anterior thalamic neuroepithelial lobule. On day E16 three migratory streams leave the anterior neuroepithelial lobule and, on the basis of their labeling pattern in relation to the neurogenetic gradients of the anterior thalamic nuclei, they are identified, from dorsal to ventral, as the putative migratory streams of the anterodorsal, anteroventral, and lateral dorsal nuclei. On day E17 the putative migratory stream of the anteromedial nucleus appears to leave the same neuroepithelial region that on the previous days was the source of the anteroventral nucleus. Dorsally, two neuroepithelial patches persist after day E17 and these are identified as the putative cell lines of the anterior paraventricular and paratenial nuclei.

Animals↗
PubMed1975

Amphetamine stereotypy: the influence of environmental factors and prepotent behavioral patterns on its topography and development.

This report describes a series of experiments, all of which demonstrate a strong contribution of the behavioral pattern manifested at the time of initial amphetamine injection to the topography and development of the stereotypy that develops with chronic amphetamine intoxication. These initial behavioral patterns reflect (i) learned behaviors, (ii) species-specific behaviors, (iii) behaviors associated with amphetamine arousal, and (iv) novel behaviors reflecting unique environmental circumstances prevailing at the time of administration. In an experiment using eight dogs administered amphetamine in a situation which allowed interaction between the animals, the behavioral stereotypies that developed were comprised of the social interaction patterns ongoing at the time of initial drug effects. Experiments with rats have demonstrated that the configuration of the enclosure in which they are injected influences the initial behavioral reactions to amphetamine and thus modifies the stereotypy. In experiments with cats pressing a lever to self-administer amphetamine, investigatory behavior at the lever-press operandi becomes incorporated as does the learned behavior response into the stereotypy. The behavioral patterns originally associated with amphetamine arousal eventually supersede the learned response component of the stereotypy. Finally, monkeys incorporate components of the initial behaviors associated with amphetamine administration into a wider range of stereotype patterns over months of chronic intoxication, and eventually the stereotypy may evolve into a specific dyskinesia involving movements of the original behavioral component.

Animals↗