Base-compositional biases and the bat problem. II. DNA-hybridization trees based on AT- and GC-enriched tracers

We conducted a series of parallel DNA-hybridization experiments on a small group of bats (species of Pteropus, Rhinolophus, Noctilio and Pteronotus) and outgroups (Lemur, Cynocephalus, Didelphis), using whole-genome labels and tracers made from extracts enriched with AT and two levels of GC content. FITCH (additive phylogenetic trees) topologies were constructed from the four sets of comparisons, indexed as both delta Tmode and delta NPHs (normalized percentage of hybridization). Based on our previous work showing that the shared AT bias of pteropodids and some microchiropterans may affect the rank-ordering of taxa based on either AT- or GC-rich labels, our expectation was that the resulting trees would show differing topologies when generated from tracers made with the variously enriched DNA extracts. Whereas there was some variation among the trees, most of them grouped the bats together, and almost all paired the representative megachiropteran and rhinolophoid microchiropteran as sister-taxa in contrast to the other microchiropterans. As the pteropodid-rhinolophoid relationship is an unexpected and unlikely one, we attribute this association to an AT bias that was not obviated even by our most GC-rich labels, and suggest that such a bias may compromise the truth of some molecular trees. Accordingly, we believe the broader issue of bat monophyly remains unresolved by DNA-hybridization and probably also by gene-sequencing studies.     

Computer assisted neurophysiology by a distributed Java program

The mere appearance of a tubular, epithelially-covered, bilateral structure, no matter how minuscule, on the anteroventral nasal septum of tetrapods, is generally called the vomeronasal organ (of Jacobson). However, considering the functionality of this chemosensory structure, the presence of a non-cilated (microvillar) neuroepithelium (and not just any odd type of epithelium) encased in a variously shaped vomeronasal cartilage, along with vomeronasal nerve bundles and above all an accessory olfactory bulb connected to the limbic vomeronasal amygdala, are the absolute essential neurostructural characteristics and anatomic requirement for a functional VNO and the accessory olfactory system in any tetrapod. The distribution of the vomeronasal organ is reported here in two mammalian orders: Chiroptera and Primates. An impressive data pool on the vomeronasal organ of bats is now available, pointing to the fact that at this time bats may be the only group in which this organ system is extremely variable, ranging from total absence (even in the embryo) to spectacular development with numerous intervening stages in different chiropteran species. Of the eighteen bat families, only one family of New World leaf-nosed bats, family Phyllostomidae, exhibits functional vomeronasal organs. The vespertilionid bat Miniopterus, and the mormoopid bat Pteronotus, present exceptions to this rule. Among Primates, very few species have been rigorously studied. As a result, developmental variability of the vomeronasal organ is almost unknown; either the vomeronasal organ is well developed (such as in New World monkeys) or absent (as in Old World monkeys and great apes) in the adult. The concept whether adult humans or embryonic and fetal forms are endowed with this so-called sixth sense, is a controversial one and is under intense study in our laboratory and by others. The general phylogenetic implications based on our cladistic analysis of bats are that the vomeronasal organ complex has evolved several times. Among the prosimians and platyrrhine primates, the organ is well developed, although to a varying degree. Among catarrhine primates, its loss has occurred only once, as it is generally absent in the adult forms.     

Bats, cats, and rabies in an urban community

Bats are the primary vectors of rabies in humans in the United States. In the urban environment they generally are found within buildings where they may bite people or be attacked by cats or dogs. Given the high probability that any bat that bites a person may be rabid, antirabies prophylaxis should be administered as soon as possible after the incident. This should not be delayed pending laboratory results on the bat. Children should be taught to avoid contact with moribund bats. Cats are more likely to be involved with rabid bats than dogs, but they are less likely to be vaccinated against rabies. The occasional rabid cat in an urban community may have acquired its infection from a bat. Therefore, it is vital that communities enforce rabies vaccination for cats as well as dogs.     

Identification of marker chromosomes and translocations in man using a computerized diagnostic database and fluorescent in situ hybridization

BACKGROUND: Many species of bats have two sets of submandibular glands, principal and accessory. The accessory gland may resemble the principal one but more often shows wide morphological divergence. The free-tailed bat, Tadarida thersites, is very unusual in that it has two sets of parotid glands rather than binary submandibular glands. We studied the ultrastructure of the principal parotid gland to establish a baseline for comparison with the accessory parotid. METHODS: Two specimens of adult free-tailed bats, one male and one female, were live-trapped in western Kenya. Parotid glands were fixed for electron microscopy using a protocol expressly designed for field fixation and then embedded by conventional means. RESULTS: Histologically, the principal parotid is a typical serous gland. The secretory granules of the endpiece cells have an unusual substructure in that they contain variable numbers of lucent halos and one or several spherules. Intercalated duct cells contain a significant number of dense, serous-like granules. Striated ducts have the usual basal configuration of mitochondria and folded plasma membranes, but the supranuclear cytoplasm contains many small, dense granules, so that these ducts resemble the granular convoluted tubules found in the submandibular glands of many families of rodents. The apices of the duct cells have a peculiar contour--the luminal surfaces obliquely invaginate into the apical cytoplasm, so that in thin section the luminal membranes appear to be underlaid by a layer of vacuoles. CONCLUSION: Although the principal parotid gland of the free-tailed bat shows some distinctive, species-specific ultrastructural features, it basically is similar to the parotid gland in two other molossid bats, Tadarida brasiliensis and Molossus molossus. The distinctive features in the principal parotid gland of T. thersites might relate to its feeding on hard-bodied insects and perhaps to the production of lysozyme.     

Complex sound analysis in the FM bat Eptesicus fuscus, correlated with structural parameters of frequency modulated signals

Big brown bats, Eptesicus fuscus, were presented with artificial frequency modulated (FM) echoes that simulated an object becoming progressively closer to the bat. A stereotyped approach phase behavioral response of the bat to the virtual approaching target was used to determine the ability of the bat to analyze FM signals for target distance information. The degree to which the bats responded with approach phase behavior to a virtual approaching target was similar when they were presented with either a naturally structured artificial FM echo or an artificial FM echo constructed from a series of brief pure tone steps. The ability of the bats to respond to an FM signal structured from a sequence of pure tone elements depended on the number of pure tone steps in the series; the bats required the presentation of tone-step FM signals containing about 83 or greater pure tone elements. Moreover, the duration of the individual tone steps of the tone-step FM signals could not exceed a specific upper limit of about 0.05 ms. Finally, it appears that the bats were able to independently resolve individual tone steps within the tone-step FM signals that were separated by about 450 Hz or more.     

Classification of virtual objects in the echolocating bat, Megaderma lyra.

Using echolocation, bats can not only locate objects in space but also discriminate objects of different shape. The acoustic image of an object is its impulse response (IR). The current experiments investigate whether bats just perceive changes in echo composition or whether bats perceive the IR itself through a detailed comparison of the emitted sound with the echo. The bat Megaderma lyra was trained to classify unknown virtual objects according to learned reference objects of different temporal and spectral composition. The bats' spontaneous classification was compared to predictions based on various physical and simulated peripheral auditory representations of the objects. The results show that the bats developed an accurate internal representation of the objects' IRs. In the auditory periphery, the IRs of small objects (     

An outbreak of vampire bat bite in a Brazilian village

An outbreak of 26 cases of vampire bat bite in one month in the rural area of Honorópolis, a Brazilian village, is reported. All patients were bitten during the night, when they were asleep, and most bites were on their toes. No complication attributed to the bite was reported. The patients were given prophylactic antirabies serum and rabies vaccine. Control of the outbreak was achieved by visiting bat roosting sites, smearing captured vampire bats (Desmodus rotundus) with a paste of 2% warfarin in vaseline, and releasing them. No case of human or animal rabies was diagnosed in a 5-month follow-up. A possible explanation for the outbreak of bat bite is that, because of man-induced environmental modifications in their habitats, vampire bats in Honorópolis now live in the peridomiciliar area, where people are more exposed to their bites. An alternative explanation is related to the use in cattle of a pyrethroid insecticide to control the horn fly, Haematobia irritans, as both events were temporally related. The insecticide could have had a repellent effect on bats, that then started to seek alternative food sources.     

Babesia sp. in Colombian bats (Microchiroptera)

Two leaf-chinned bats (Mormoops megalophylla) collected in 1963 in central Colombia were heavily infected with Babesia sp., probably Babesia vesperuginis. Both bats had pronounced splenomegaly. This is the first report of a Babesia sp. infection of a bat in the Americas.     

Neural computations for sound pattern recognition: evidence for summation of an array of frequency filters in an echolocating bat

Microchiropteran bats use an auditory sonar system for orientation and prey capture. Many bats use highly structured constant-frequency (CF) and frequency-modulated (FM) sonar orientation signals. Mechanisms for sound pattern recognition are important for the perception of these and other types of auditory signals. The processing and recognition of FM sound components appears to be important for certain complex perceptual tasks, including target distance perception. I have conducted behavioral studies using artificial echoes to simulate the conditions of a bat flying toward a target. An innate vocalization response of the bat to the simulated approaching target was used to assess the ability of the bat to analyze the structure of and extract distance information from different types of synthetic FM sound patterns. The bat's performance depended on the structure of the artificial echo. The pattern recognition performance of the bats was similar when they were presented with either a naturally structured artificial CF/FM echo or an artificial CF/FM echo containing an FM component consisting of a series of pure tone steps. The ability of the bats to recognize appropriately the structure of an FM signal constructed from a sequence of pure tones depended on the number of pure tone steps in the series. Noctilio was able to recognize FM sound patterns containing 99 or greater pure tone steps. The minimum required number of pure tone steps could be distributed over different frequency ranges. The bats were able to resolve individual tone steps in the series that were separated by at least 100 Hz.(ABSTRACT TRUNCATED AT 250 WORDS)     

Megachiropteran bats (pteropus) utilize human referential stimuli to locate hidden food.

Spontaneous point-following behavior has been considered an indicator of advanced social cognition unique to humans. Recently, it has been suggested that a close evolutionary relationship with humans could result in similar social skills in domesticated species. An alternative view is that the mechanism is not genetic domestication alone but instead a combination of phylogenetic and ontogenetic variables. Here we test the necessity of phylogenetic domestication by investigating the point-following behavior of a captive population of nondomesticated megachiropteran bats (Pteropus pumilus, Pteropus rodricensis, Pteropus conspicillatus, Pteropus vampyrus). Three of five subjects were highly successful in following an unfamiliar human's point to a target location, providing the first empirical evidence of cross-species social referencing in bats. The three successful bats were all born in captivity and socialized to humans early in life, whereas unsuccessful bats were wild-born individuals. This study provides evidence that referential point following is not restricted to domesticated animals and indicates that early experience may be important. Megachiropteran bats may prove to be a useful model for studying social behaviors. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Hearing in a megachiropteran fruit bat (Rousettus aegyptiacus).

The Egyptian fruit bat (Rousettus aegyptiacus) is one of the few megachiropteran bats capable of echolocation. However, it uses rudimentary tongue clicks rather than laryngeally produced echo calls. We determined the audiogram of 2 bats using a conditioned avoidance procedure with fruit puree reward. At an intensity of 60 dB sound pressure level, the bats' hearing extended from 2.25 kHz to 64 kHz, with a region of good sensitivity between 8 kHz and 45 kHz. A dip in sensitivity at 32 kHz appears to be due to pinna directionality. The hearing of Egyptian fruit bats is typical for a mammal of that size and is not as limited as previously reported. Methodological issues, specifically training an animal to listen for low-intensity signals and imposing a significant cost for failing to report signals (i.e., misses), are discussed as the basis for the discrepancy between our results and earlier reports. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conformational investigation of alpha,beta-dehydropeptides. IX. N-Acetyl-(E)-alpha,beta-methylamide: stereoelectronic properties from infrared and theoretical studies

BACKGROUND: Basal folds are slender plications at the basal surface of acinar cells in the salivary glands of many mammalian species. These largely organelle-free folds increase the surface area of the basal plasmalemma manyfold and are unquestionably involved in the translocation of organic and inorganic molecules and water into the acinar cells. METHODS: Specimens of salivary glands were obtained from over 230 species of live-trapped bats from major areas of the globe. Tissues for electron microscopy were fixed and processed by conventional means. RESULTS: A number of the bat species examined had dense material in the intercellular spaces between basal and lateral folds of serous cells in the parotid gland. This intercellular material was particularly prominent in three species of New World bats, viz., Pteronotus parnellii, P quadridens, and Phyllostomus latifolius, and in one species of Old World bats, Chalinolobus argentatus. This dense material, which has a farinaceous texture, appears not to pass through tight junctions, so it is excluded from the lumina of intercellular canaliculi and acini. The dense material originates in the acinar cells--it is carried to the membranes of the folds via coated vesicles, which empty their dense content by exocytosis into the intercellular space. Similar dense material is present in the intercellular spaces of the basal labyrinth of striated ducts in the two species of Pteronotus. The manner in which this material accumulates in the striated duct is unclear. CONCLUSIONS: Although the function of the intracellular dense material is undetermined, it appears to be placed strategically to influence molecular traffic into acinar cells or to modulate the paracellular pathway. From a comparative evolutionary perspective, we hypothesize that, in bats, the combination of basal folds and extracellular densities is associated with insectivory. Similar morphologies appear to be lacking in frugivorous or nectarivorous species.     

Outbreak of vampire bat biting in a Venezuelan village

An outbreak of 154 cases of vampire bat biting in a four-month period in the gold mine of Payapal, a Venezuelan village, is reported. All patients were bitten during the night and the most bites were on their toes. No complication attributed to the bite was reported. Diagnoses of rabies virus made by means of immunofluorescence were negative. A possible reason for this outbreak may been the development of mining areas, with the inhabitants providing an alternative food source for the bats.     

Use of binaural cues for sound localization in two species of Phyllostomidae: The Greater spear-nosed bat (Phyllostomus hastatus) and the Short-tailed fruit bat (Carollia perspicillata).

Unlike humans, not all mammals use both of the binaural cues for sound localization. Whether an animal uses these cues can be determined by testing its ability to localize pure tones; specifically, low frequencies are localized using time-difference cues, and high frequencies are localized using intensity-difference cues. We determined the ability to use binaural cues in 2 New World bats, Phyllostomus hastatus, large omnivores, and Carollia perspicillata, small frugivores, by testing their tone-localization ability using a conditioned avoidance procedure. Both species easily localized high-frequency tones, indicating that they could use the interaural intensity-difference cue. However, neither species was able to use the phase-difference cue to localize either low-frequency pure tones or amplitude-modulated tones (which provided an envelope for additional time analysis). We now know of 3 bat species that cannot use binaural time cues and 2 that can. Further exploration of localization in bats may provide insight into the neural analysis of time cues in species that do not hear low frequencies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Collective narcissism and its social consequences.

This article introduces the concept of collective narcissism—an emotional investment in an unrealistic belief about the in group’s greatness—aiming to explain how feelings about an ingroup shape a tendency to aggress against outgroups. The results of 5 studies indicate that collective, but not individual, narcissism predicts intergroup aggressiveness. Collective narcissism is related to high private and low public collective self-esteem and low implicit group esteem. It predicts perceived threat from outgroups, unwillingness to forgive outgroups, preference for military aggression over and above social dominance orientation, right-wing authoritarianism, and blind patriotism. The relationship between collective narcissism and aggressiveness is mediated by perceived threat from outgroups and perceived insult to the ingroup. In sum, the results indicate that collective narcissism is a form of high but ambivalent group esteem related to sensitivity to threats to the ingroup’s image and retaliatory aggression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social perception as induction and inference: An integrative model of intergroup differentiation, ingroup favoritism, and differential accuracy.

Three general properties of social stereotypes are the perception of differences between ingroups and outgroups (intergroup differentiation), the perception of ingroups as having more desirable attributes than outgroups (ingroup favoritism), and the greater accuracy of ingroup perceptions (differential accuracy). We present and test an inductive-reasoning model that accounts for all 3 phenomena, and we explicate the relations among them. Based on empirical evidence, the model assumes that most people have a positive self-image, that they project these self-images more strongly to ingroups than to outgroups, and that their self-images are valid cues for judgments about social groups. Two minimal-group experiments using a crossed-categorization paradigm support the model and provide new evidence for underlying psychological processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emergenesis: Genetic traits that may not run in families.

Traits that are influenced by a configuration, rather than by a simple sum, of polymorphic genes may not be seen to be genetic unless one studies monozygotic twins (who share all their genes and thus all gene configurations) because such "emergenic" traits will tend not to run in families. Personal idiosyncrasies that have been found to be surprisingly concordant among monozygotic twins separated in infancy and reared apart may be emergenic traits. More speculatively, important human traits like leadership, genius in its many manifestations, being an effective therapist or parent, as well as certain psychopathological syndromes may also be emergenic. These ideas reemphasize the importance of the role played in human affairs by genetic variation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of c-Fos and glial fibrillary acidic protein (GFAP) expression following topical application of potassium chloride (KCl) to the brain surface

The mustached bat, Pteronotus p. parnellii, has a finely tuned cochlea that rings at its resonant frequency in response to an acoustic tone pip. The decay time (DT) and frequency of these damped oscillations can be measured from the cochlear microphonic potential (CM) to study changes in cochlear mechanics. In this report, we describe phasic changes that occur in synchrony with communication sound vocalizations of the bat. Three animals with chronically implanted electrodes were studied. During the experiments, 1-2 ms tone pips were emitted from a speaker every 200 ms. This triggered a computer analysis of the resulting CM to determine the DT and cochlear resonance frequency (CRF) of the ringing. The time relative to vocalizations was determined by monitoring the output of a microphone placed near a bat's mouth. Similar results were obtained from all three bats tested. In a representative case, the average DT was 2.33 +/- 0.25 ms while the bat was quiet, but it decreased by 46% to 1.26 +/- 0.75 during vocalizations, which indicates a greater damping of the cochlear partition. Sometimes, DT started decreasing immediately before the bat vocalized. After the end of a vocalization, the return to baseline values varied from rapid (milliseconds) to gradual (1-2 seconds). The CRF also changed from baseline values during vocalization, although the amount and direction of change were not predictable. When gentamicin was administered to block the action of medial olivocochlear (MOC) efferents, DT reduction was still evident during vocalization but less pronounced. We conclude that phasic changes in damping occur in synchrony with vocalization, and that the MOC system plays a role in causing suppression. Since suppression can begin prior to vocalization, this may be a synkinetic effect, mediated by neural outflow to the ear in synchrony with neural outflow to the middle ear muscles and the muscles used for vocalization.     

Marital conflict, maternal and paternal parenting, and child adjustment: A test of mediation and moderation.

Parenting was examined as a mediator of associations between marital and child adjustment, and parent gender was examined as a moderator of associations among marital, parental, and child functioning in 226 families with a school-age child (146 boys). Parenting fully mediated associations between marital conflict and child internalizing and externalizing behaviors. Parent gender did not moderate associations when data from the full sample or families with girls only were evaluated. Parent gender did moderate associations when families with boys were evaluated, with the association between marital conflict and parenting stronger for fathers than mothers. A trend suggested fathers' parenting may be more strongly related to internalizing behavior and mothers' parenting may be more strongly related to externalizing behavior in boys. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Molecular systematics of Phlebotominae: a pilot study. Paraphyly of the genus Phlebotomus

Phylogenetic relationships among Phlebotominae were inferred through a pilot study using parsimony analysis of the D2 domain of ribosomal DNA sequences: 455 pairs of bases were sequenced in nine species of Phlebotomine sandflies which belong to the genera Lutzomyia, Phlebotomus and Sergentomyia. Two taxa are used as outgroups: Psychoda sp. and Nemapalpus flavus which is the sister group of the Phlebotominae. The South American genus Lutzomyia appears to be monophyletic. The Mediterranean species Sergentomyia dentata is its sister group and is not clustered with the Old World genus Phlebotomus. The latter is a paraphyletic genus with an early individualization of the branch including the closely related subgenera Phlebotomus and Paraphlebotomus, and a late individualization of the subgenus Larroussius. These results have some consequences on the biogeography of the leishmaniasis in the Old World.