True handedness in the cotton-top tamarin (Saguinus oedipus)?

Hand use for 8 activities was studied in 20 captive cotton-top tamarins (Saguinus oedipus). The purpose of the study was to discover if hand preferences existed across tasks and across subjects, and, if so, whether these followed the patterns of preference inMacNeilage et al.'s (1987) “postural origins” theory of the evolution of hand preference and hemispheric specialization in primates. This theory suggests that, for haplorines, the right hand is used preferentially for manipulative acts while the left hand is used preferentially for visually guided acts. The study showed statistically significant right hand preferences for six of the seven actions which produced sufficient data to be tested. The strength and consistency of this preference makes this study the first to suggest true handedness in a non-human primate species. Deviations from the pattern were seen in scratching and other actions when performed in a vertical posture, but these deviations took the form of a weakening of the right hand preference rather than a reversal. The findings of the study may be seen as supportingMacNeilage et al.'s (1987) theoryonly if the actions studied are all considered to be manipulative, which can be argued to be the case, though some of the actions were also visually guided.     

Distinct haptic cues do not reduce interference when learning to reach in multiple force fields

Background

Previous studies of learning to adapt reaching movements in the presence of novel forces show that learning multiple force fields is prone to interference. Recently it has been suggested that force field learning may reflect learning to manipulate a novel object. Within this theoretical framework, interference in force field learning may be the result of static tactile or haptic cues associated with grasp, which fail to indicate changing dynamic conditions. The idea that different haptic cues (e.g. those associated with different grasped objects) signal motor requirements and promote the learning and retention of multiple motor skills has previously been unexplored in the context of force field learning.

Methodology/Principle Findings

The present study tested the possibility that interference can be reduced when two different force fields are associated with differently shaped objects grasped in the hand. Human subjects were instructed to guide a cursor to targets while grasping a robotic manipulandum, which applied two opposing velocity-dependent curl fields to the hand. For one group of subjects the manipulandum was fitted with two different handles, one for each force field. No attenuation in interference was observed in these subjects relative to controls who used the same handle for both force fields.

Conclusions/Significance

These results suggest that in the context of the present learning paradigm, haptic cues on their own are not sufficient to reduce interference and promote learning multiple force fields.     

The acetic acid bacteria, 1941–1961

Summary Leifson's (1954) differentiation of the acetic acid bacteria into (1)Acetobacter—peritrichously flagellated and acetate oxidising, and (2)Acetomonas—polarly flagellated and acetate non-oxidising, has, by various workers, been (a) fully confirmed, (b) doubted, or only partly accepted, and (c) denied altogether. Also the priority ofAcetomonas overGluconobacter has been questioned, as has also facile mutability inAcetobacter. By a critical comparative review of all the publications concerned, and by the experimental examination of the various cultures claimed to contraveneLeifson's correlation, we have attempted to clarify the confusion, and to give a clear picture of the true position, which is really quite simple. The result of so doing has been to vindicateLeifson's findings in every case, to refute criticism of facile mutability inAcetobacter, and to show whyGluconobacter Asai cannot claim priority overAcetomonas Leifson.     

A phenetic comparison of someFumaria spp. (Fumariaceae)

The taxonomy of the genusFumaria has not been considered in detail sincePugsley's work in 1919 ff., and few modern methods have been applied to it. In a phenetic study, 33 populations of 11Fumaria spp. were grown in uniform conditions, and seven morphological characters measured. After re-expression and transformation the data were analysed by cluster analysis and principal components analysis. Alternative analyses did not indicate contradictory taxonomic conclusions. Artificial crosses gave some evidence on interfertility, and suggestedF. occidentalis to be an allopolyploid ofF. bastardii ×F. capreolata. Pugsley's subsectional classification is supported within sect.Parviflora, but not within sect.Grandiflora. His two sections are seen to be meaningful, but not discrete.     

Antígenos del paracoccidioides brasiliensis para las Reacciones serológicas

Summary The sera from normal subjects gave negative results with the following antigens used in the complement-fixation tests: 1) polysaccharide prepared according toFava Netto's technic; 2) a filtrate of shaked cultures followingAjello et al.'s technic; 3) an aqueous extract of mechanically disrupted yeast cells ofP. brasiliensis.The sera from patients of S.A. blastomycosis gave positive c.f. tests with the three antigens with titer ranging from 1/20 to 1/5, 160. Antigen No 2 gave in 11/18 cases higher titers than the other antigens.Immunodiffusion tests gave positive results with the antigen no 2. The sera from 10 cases of histoplasmosis gave cross reactions with the antigen No 3, in 5/10 cases with the antigen No 2 and in not any case with the antigen No 1.     

Learning how to learn: The significance and current status of learning set formation

In honor of the memory ofHarry F. Harlow, this paper reviews the current status of learning set formation, the discovery of which represents one ofHarlow's major contributions to behavioral science. Learning set formation or “learning how to learn” refers to the learning of visual and other types of discrimination problems progressively more quickly as a function of training on a series of such problems. The general procedure thatHarlow used, his original learning set finding, and its significance are described first. A brief review of theories of learning set formation follows. Lastly, the attempt to use learning set formation as a tool for studying comparative behavior is discussed. This article is based on a paper by the author delivered at:A. M. Schrier andS. J. Suomi (cochairs),Primate Behavior: A Symposium in Memory of Harry F. Harlow. Symposium presented at the IXth Congress of the International Primatological Society, Atlanta, Georgia, August 1982.     

Automatic imitation in budgerigars

A fully automated procedure, involving computer-controlled stimulus presentation and computer-recorded response measurement, was used for the first time to study imitation in non-human animals. After preliminary training to peck and step on a manipulandum, budgerigars were given a discrimination task in which they were rewarded with food for pecking during observation of pecking and for stepping during observation of stepping (Compatible group), or for pecking while observing stepping and for stepping while observing pecking (Incompatible group). The Incompatible group, which had to counter-imitate for food reward, showed weaker discrimination performance than the Compatible group. This suggests that, like humans, budgerigars are subject to 'automatic imitation'; they cannot inhibit online the tendency to imitate pecking and/or stepping, even when imitation of these behaviours interferes with the performance of an ongoing task. The difference between the two groups persisted over 10 test sessions, but the Incompatible group eventually acquired the discrimination, making more counter-imitative than imitative responses in the final sessions. These results are consistent with the associative sequence learning model, which suggests that, across species, the development of imitation and the mirror system depends on sensorimotor experience and phylogenetically ancient mechanisms of associative learning.     

Selfing inNarthecium ossifragum (Melanthiaceae)

Hagerup's (1950) observations of rain pollination inNarthecium ossifragum are commonly admitted. Nevertheless,Daumann (1970) stated that pollen and stigmas suffer considerable damage from rain impact. Experimental pollinations and pollen observations were conducted at a single site in the Upper Ardennes, Belgium, during three years. Rain water had a deleterious effect on both fruit and seed set and on pollen germination. Fruit and seed set differed among years mainly due to rainy weather. Fruit set also varied among experimental treatments. Pollination trials showed thatNarthecium ossifragum is self-compatible and autofertile. Emasculation had a deleterious effect and caging had no effect on fertility.     

Evaluation ofDrosophila melanogaster as an alternative animal for studying the neurotoxicity of heavy metals

Heavy metals cause irreversible neurobehavioral damage in many developing mammals, but the mechanisms of this damage are unknown. The influence of three heavy metal compounds, triethyllead chloride, lead acetate and cadmium chloride, on lethality, development, behavior and learning was studied using the fruit fly,Drosophila melanogaster. This animal was used because it allows hundreds of subjects to be assayed very easily in individual experiments and because it is a system in which toxicological questions might be answered by using the techniques of modern molecular genetics. When triethyllead chloride, lead acetate or cadmium chloride was placed in the medium, the larval LC₅₀ (± standard error) was found to be 0.090±0.004, 6.60±0.64 and 0.42±0.04mm, respectively. Each of the tested compounds produced a dose-related delay in development. In particular, they caused a delay in the development of larvae to pupae. When larvae were reared on medium containing triethyllead chloride (0.06mm), lead acetate (3.07mm) or cadmium chloride (0.11mm), phototaxis, locomotion and learning were not inhibited. Since significant neurobehavioral effects were not observed under the experimental conditions used,Drosophila does not appear to be an appropriate animal for the genetic dissection of such effects of heavy metals during development.     

Genetic variation of blood proteins within and between local populations of grivet monkey (Cercopithecus aethiops aethiops) in central Ethiopia

A population genetic study by blood protein electrophoresis revealed that populations of wild grivet monkeys in central Ethiopia show a comparatively low level of variability and less differentiation among local populations over broad geographical areas. This is evaluated by comparison with other wild primate studies using the same electrophoretic technique. A total of 196 blood samples, collected from 10 local populations comprising 11 troops distributed along approximately 600 km of the Awash River, were examined for 33 genetic loci. The low level of variability was indicated by the proportion of polymorphic loci (P_poly), which was on average 11% with an average heterozygosity (H) of 3%. A tendency for lower genetic differentiation among local populations was shown by theG _ST value of 0.09, an averageF _ST of 0.08, andNei's genetic distance; ranging from 0.002 to 0.023. Considering paleoclimatological studies of the area and ecological traits of this species, these findings can be explained as a consequence of a comparatively recent and repeated series of rapid habitat expansions following severe climatic conditions.     

Researches on the etiological agents of the american blastomycosis

Summary and conclusion We have been able to establish typical characteristics of the species, in artificial culture media, of the fungus causingPosadas-Wernicke's disease. Our work is base on the study of ten strains of the fungus and on their retrocultures — obtianed by inoculation of these strains in laboratory animals — in variosu culture media, among them cornmeal agar (Emmons media) which in our opinion is a medium indispensable for the differencing and for the classification of the fungus from other agents which produce syndromes of a like nature.A revision was made of the literature of the morphology of the causal agent ofPosadas-Wernicke's disease and an analysis of the predominant and characteristic fructification of the fungus. In attention to the above facts, we think that the fungus in question should be included in the genusAleurisma Link, 1809. Therefore, admitting the validity of this genus, we believe that the name of the etiological agent ofPosadas-Wernicke's disease should be changed toAleurisma immitis, the diagnosis being justified by the microscopic study inEmmons media and completed by the forms found in a medium rich in glycides. The diagnoses is the following: Aleurisma immitis. — In substratis pauperibus gignuntur hyphis mycelicis hyalinis, septatis, satis ramosis, ramulis in angulo pene recto; aleuriis abundantissimis, valde simplicibus, centralibus et regulariter seriatis, vel apicalibus, rarissime lateralibus, sessilibus, rare pedicellatis, rectangularibus, hyalinis, aliquoties in racemis et thyrsis dispositis. Spirae saepe videntur. In substratis carbohydratis plenis, chlamydosporis intercalaribus et apicalibus abundantibus; aleuriis et spiris nec numerosis aut typicis quam in pauperibus substratis.(so called Coccidioidomycosis)     

The Zbinden method for the micro-estimation of copper after preliminary deposition of the metal by electrolysis

Summary Zbinden's method for estimating micro quantities of electrolytically separated copper by reversal of current has been investigated. Though the theoretical basis of the method proved to be more intricate than was to be expected fromZbinden's papers, standardization of the experimental conditions resulted in the development of a simple method for the determination of from 10–100g of copper. This method is very well adapted to routine work and may be carried out by untrained or hardly trained personnel.Without doubt essentially the same procedure may be used for the estimation of greater quantities of copper. In that case standardization at a higher amperage of the dissolving current seems advisable.     

Electrophoretically estimated genetic distance and divergence time between chimpanzee and man

Amount of genetic differentiation between chimpanzee and man was estimated from the result of comparative electrophoretic screening of blood protein variations at 32 independent genetic loci. TheNei's genetic distance (D) was calculated as 0.4514, and from this value the divergence time between the two species was estimated as 2.26 million years; considering the variation among amino-acid substitution rate in different proteins, the corrected figures were given as genetic distance of 0.5706 and divergence time of 2.85 million years. This genetic difference is considered too small the two species to be allocated in different families, in accordance with the results of the similar kind of analyses byKing andWilson (1975) and Bruce andAyala (1979). Discussions were made for a discrepancy between the divergence times estimated by using and not by using the splitting time recognized by paleoprimatologists as a reference, and for the difference in the estimations made in different laboratories.     

S-100 protein subunits in bovine oviduct epithelium:In situ distribution and changes during primary cell culture

Summary Cultures of bovine oviduct epithelial cells are widely used in co-culture systems to improve the results ofin vitro fertilization. The aim of the present study was to evaluate the suitability of S-100 protein as a differentiation marker for bovine oviduct epithelial cellsin vitro. The distribution of S-100α and S-100β was examined immunohistochemically in bovine oviduct epitheliumin situ and in primary cell cultures derived from it. Three segments of the Fallopian tube (isthmus, ampulla and fimbriae) were compared and analysed during different stages of the oestrus cycle (luteal phase and follicular phase). Ciliated and non-ciliated cells of the epithelium reacted with anti-S-100α, S-100a(αβ) and S-100β antibodies, except for isthmic non-ciliated cells, which did not bind anti-S-100β or anti-S-100a(αβ). In addition, basal cells never showed immunoreactivity for S-100. In confluent monolayers of cultured oviduct epithelial cells, disappearance of reactivity for S-100 paralleled morphological signs of dedifferentiation (loss of cilia, cytoplasmic vacuolization). Free-floating oviduct epithelial cells, in contrast, retained morphological differentiation and still expressed S-100 antigen even after seven daysin vitro. The immunohistochemical findings were confirmed by polyacrylamide gel electrophoresis and Western blotting. The results indicate that the presence of S-100 is closely connected to morphological differentiation and to the specific functional condition of bovine oviduct epithelial cells.     

Stochastic development of cell populations under non-homogeneous conditions

Studies on the development of cell populations are often based on results of the theory of stochastic birth- and death-processes (continuous or discrete (seee.g. references inVogel, Niewisch &Matioli (1969), in some cases, death may be interpreted not as actual death of the cell bute.g. as a recruitment of the cell considered into another cell compartment, etc.). It is usually assumed that the conditions for the development are homogeneous,i.e. that the probabilities of births and deaths are independent on the time. However, in most situations, this assumption is not fulfilled (owing to the maturation and differentiation of cells, changes of the microenvironment, inducing factors, etc.). Then it is necessary to study the development of cell populations under non-homogeneous conditions. In this paper, some properties of appropriate birth- and death-processes under nonhomogeneous conditions are studied; formulae given in section 4 permit calculation of some characteristics describing the cell population size distribution at individual discrete epochs (at individual generations) during the development of the cell population considered.     

Performance of mice in an automated olfactometer: odor detection, discrimination and odor memory

Mice were trained on a variety of odor detection and discrimination tasks in 100- or 200-trial sessions using a go, no-go discrete trials operant conditioning procedure. Odors, presented for 1 s on each trial, were generated by an air dilution olfactometer (for threshold tests) and an easily constructed eight-channel liquid dilution unit (for two- and multiple-odor discrimination tasks). Mice rapidly acquired the operant task and demonstrated excellent stimulus control by odor vapors. Their absolute detection threshold for ethyl acetate was similar to that obtained with rats using similar methods. They readily acquired four separate two-odor discrimination tasks and continued to perform well when all eight odors were presented in random order in the same session and when reinforcement probability for correct responding was decreased from 1 to 0.5. Memory for these eight odors, assessed under extinction after a 32 day rest period, was essentially perfect. Time spent sampling the odor on S+ and S- trials was highly correlated with response accuracy. When accuracy was at chance levels (e.g. initial trials on a novel task), stimulus sampling time on both S+ and S- trials was approximately 0.5-0.7 s. As response accuracy increased, sampling time on S+ trials tended to increase and remain higher than sampling time on S- trials.     

Intra- and interspecific genetic differentiation in closely related pines fromPinus subsectionSylvestres (Pinaceae) in the former Soviet Union

Thirty-seven natural populations of four closely related species ofPinus subsect.Sylvestres, P. mugo, P. funebris, P. pallasiana, andP. sylvestris, occurring in the former Soviet Union were investigated by starch-gel electrophoresis. In the populations assayed 127 allelic variants at 25 loci were revealed.Nei's distance coefficient (Dn) was used to estimate the level of genetic differentiation amongP. sylvestris races and among closely related species. A dendrogram constructed using Dn values shows that of the fiveP. sylvestris races analyzed only the geographically isolated var.hamata exhibited sufficient differences at theDia-2 locus (a mean Dn value relative to the other four races is 0.025) to recognize it as a distinct taxon. The remaining races, sylvestris, cretacea, lapponica, and sibirica, have a similar gene pool (Dn values are not greater than 0.010), and they should be regarded as a single taxon,P. sylvestris var.sylvestris. Interspecific comparisons revealed thatP. sylvestris andP. mugo have the closest genetic affinities to each other withNei's genetic distance of 0.108. The dendrogram demonstrates thatP. funebris is closer toP. sylvestris andP. mugo thanP. pallasiana. The available paleontologic data allowed us to conclude thatNei's (1975) time scale estimate for the time of divergence of the taxa was more accurate thanNei's (1971) time scale estimate.     

Allozyme divergence among four species ofPodaechmea s. l. and the status ofUrsulaea (Bromeliaceae, Bromelioideae)

The genetic relationships ofAechmea mexicana, A. lueddemanniana, A. macvaughii andA. tuitensis were investigated using starch gel electrophoresis. Eight enzyme systems encoded by ten putative gene loci were resolved in seventeen populations.Nei's (1978) genetic distances were obtained from allelic frequencies and used with UPGMA algorithm. Results indicate that some populations belonging to different species display genetic similarities closer to each other than to some conspecific populations. Our results do not support the proposed genusUrsulaea (Read & Baensch 1994), sinceA. tuitensis was closer toA. lueddemanniana andA. mexicana than toA. macvaughii.     

Morphological and cytological investigations ofUlothrix zonata and taxonomy of the related species

The present communication deals with the observations made on the morphology, reproduction and cytology ofUlothrix zonata (Weber & Mohr)Kütz. in culture. The alga displays a remarkable phenotypic plasticity in nature as well as in culture. The present study provides additional evidence of karyology in support ofLokhorst andVroman's treatment ofU. zonata which merges a number of earlier described species in it. The cytological details and chromosome number (n = 10) determined for the Indian isolates ofU. zonata agree with those ofSarma for the British material.NBRI Research Publication No. 63 (N.S.)     

A novel N-carbamoyl-L-amino acid amidohydrolase of Pseudomonas sp. strain ON-4a: purification and characterization of N-carbamoyl-L-cysteine amidohydrolase expressed in Escherichia coli

N-carbamoyl-l-cysteine amidohydrolase (NCC amidohydrolase) was purified and characterized from the crude extract of Escherichia coli in which the gene for NCC amidohydrolase of Pseudomonas sp. strain ON-4a was expressed. The enzyme was purified 58-fold to homogeneity with a yield of 16.1% by three steps of column chromatography. The results of gel filtration on Sephacryl S-300 and SDS-polyacrylamide gel electrophoresis suggested that the enzyme was a tetramer protein of identical 45-kDa subunits. The optimum pH and temperature of the enzyme activity were pH 9.0 and 50°C, respectively. The enzyme required Mn²⁺ ion for activity expression and was inhibited by EDTA, Hg²⁺ and sulfhydryl reagents. The enzyme was strictly specific for the l-form of N-carbamoyl-amino acids as substrates and exhibited high activity in the hydrolysis of N-carbamoyl-l-cysteine as substrate. These results suggested that the NCC amidohydrolase is a novel l-carbamoylase, different from the known l-carbamoylases.