Singing strategies are linked to perch use on foraging territories in heart-nosed bats

Acoustic communication allows animals to coordinate and optimize resource utilization in space. Cardioderma cor, the heart-nosed bat, is one of the few species of bats known to sing during nighttime foraging. Previous research found that heart-nosed bats react aggressively to song playback, supporting the territorial defense hypothesis of singing in this species. We further investigated the territorial defense hypothesis from an ecological standpoint, which predicts that singing should be associated with exclusive areas containing a resource, by tracking 14 individuals nightly during the dry seasons in Tanzania. We quantified the singing behavior of individuals at all perches used throughout the night. Using home range analysis tools, we quantified overall use, night ranges and singing ranges, as well as areas used in early and later time periods at night. Males sang back and forth from small (x over bar = 3.48 +/- 2.71 ha), largely exclusive areas that overlapped with overall night ranges used for gleaning prey. Individuals varied in singing effort; however, all sang significantly more as night progressed. Subsequently, areas used earlier at night and overall use areas were both larger than singing areas. Individuals varied in singing strategies. Some males sang for long periods in particular trees and had smaller core areas, while others moved frequently among singing trees. The most prolific singers used more perches overall. Our results support the hypothesis that acoustic communication repertoires evolved in support of stable foraging territory advertisement and defense in some bats

Assessment of Feigned Neurocognitive Impairment in Retired Athletes in a Monetarily Incentivized Forensic Setting

Compromised validity of test data due to exaggeration or fabrication of cognitive deficits inhibits the capacity to establish appropriate conclusions and recommendations in neuropsychological examinations. Detection of feigned neurocognitive impairment presents a formidable challenge, particularly for evaluations involving possibilities of significant secondary gain. Among specific populations examined in this domain, litigating mild traumatic brain injury (mTBI) samples are among the most researched. One subpopulation with potential to contribute significantly to this body of literature is that of retired athletes undergoing fixed-battery neuropsychological evaluations within an assessment program. Given the considerable prevalence of concussions sustained by athletes in this sport and the substantial monetary incentives within this program, a unique opportunity exists to establish rates of feigning within this population to be compared to similar forensic mTBI samples. Further, a fixed battery with multiple validity tests (VT) offers a chance to evaluate the classification accuracy of an aggregated VT failure paradigm, as uncertainty abounds regarding the optimal approach to the recommended use of multiple VTs for effort assessment. The current study seeks to examine rates of feigned neurocognitive impairment in this population, demonstrate prediction accuracy equivalence between models based on aggregated VT failures and logistic regression, and compare classification performance of various individual VTs

HiRel: Hybrid Automated Reliability Predictor (HARP) integrated reliability tool system, (version 7.0). Volume 1: HARP introduction and user's guide

The Hybrid Automated Reliability Predictor (HARP) integrated Reliability (HiRel) tool system for reliability/availability prediction offers a toolbox of integrated reliability/availability programs that can be used to customize the user's application in a workstation or nonworkstation environment. HiRel consists of interactive graphical input/output programs and four reliability/availability modeling engines that provide analytical and simulative solutions to a wide host of reliable fault-tolerant system architectures and is also applicable to electronic systems in general. The tool system was designed to be compatible with most computing platforms and operating systems, and some programs have been beta tested, within the aerospace community for over 8 years. Volume 1 provides an introduction to the HARP program. Comprehensive information on HARP mathematical models can be found in the references

The DECam Ecliptic Exploration Project (DEEP) IV: Constraints on the shape distribution of bright TNOs

We present the methods and results from the discovery and photometric measurement of 26 bright (VR $>$ 24 trans-Neptunian objects (TNOs) during the first year (2019-20) of the DECam Ecliptic Exploration Project (DEEP). The DEEP survey is an observational TNO survey with wide sky coverage, high sensitivity, and a fast photometric cadence. We apply a computer vision technique known as a progressive probabilistic Hough transform to identify linearly-moving transient sources within DEEP photometric catalogs. After subsequent visual vetting, we provide a photometric and astrometric catalog of our TNOs. By modeling the partial lightcurve amplitude distribution of the DEEP TNOs using Monte Carlo techniques, we find our data to be most consistent with an average TNO axis ratio b/a $<$ 0.5, implying a population dominated by non-spherical objects. Based on ellipsoidal gravitational stability arguments, we find our data to be consistent with a TNO population containing a high fraction of contact binaries or other extremely non-spherical objects. We also discuss our data as evidence that the expected binarity fraction of TNOs may be size-dependent

The lateral septum mediates kinship behavior in the rat

Kinship behavior in rodents has been documented in the laboratory setting but the neural mechanisms that mediate kinship behavior are not known. Here, the authors show that the lateral septum has a key role in organizing mammalian kinship behavior

Mechanics of the exceptional anuran ear

The anuran ear is frequently used for studying fundamental properties of vertebrate auditory systems. This is due to its unique anatomical features, most prominently the lack of a basilar membrane and the presence of two dedicated acoustic end organs, the basilar papilla and the amphibian papilla. Our current anatomical and functional knowledge implies that three distinct regions can be identified within these two organs. The basilar papilla functions as a single auditory filter. The low-frequency portion of the amphibian papilla is an electrically tuned, tonotopically organized auditory end organ. The high-frequency portion of the amphibian papilla is mechanically tuned and tonotopically organized, and it emits spontaneous otoacoustic emissions. This high-frequency portion of the amphibian papilla shows a remarkable, functional resemblance to the mammalian cochlea

A Role for Strain Differences in Waveforms of Ultrasonic Vocalizations during Male–Female Interaction

Male mice emit ultrasonic vocalizations (USVs) towards females during male–female interaction. It has been reported that USVs of adult male mice have the capability of attracting females. Although the waveform pattern of USVs is affected by genetic background, differences among strains with respect to USV and the effects of these differences on courtship behavior have not been analyzed fully. We analyzed USV patterns, as well as actual social behavior during USV recording, in 13 inbred mouse strains, which included laboratory and wild-derived strains. Significant effects of strain were observed for the frequency of USV emission, duration, and frequency of the waveform category. Principal component (PC) analysis showed that PC1 was related to frequency and duration, and PC2–4 were related to each waveform. In the comparison of USV patterns and behaviors among strains, wild-derived KJR mice displayed the highest scores for PC2–4, and female mice paired with KJR males did not emit rejection-related click sounds. It is assumed that the waveforms emitted by KJR males have a positive effect in male–female interaction. Therefore, we extracted waveforms in PC2–4 from the USV recordings of KJR mice to produce a sound file, "HIGH2-4". As a negative control, another sound file ("LOW2-4") was created by extracting waveforms in PC2-4 from strains with low scores for these components. In the playback experiments using these sound files, female mice were attracted to the speaker that played HIGH2-4 but not the speaker that played LOW2-4. These results highlight the role of strain differences in the waveforms of male USVs during male–female interaction. The results indicated that female mice use male USVs as information when selecting a suitable mate

Versatility and Stereotypy of Free-Tailed Bat Songs

In mammals, complex songs are uncommon and few studies have examined song composition or the order of elements in songs, particularly with respect to regional and individual variation. In this study we examine how syllables and phrases are ordered and combined, ie “syntax”, of the song of Tadarida brasiliensis, the Brazilian free-tailed bat. Specifically, we test whether phrase and song composition differ among individuals and between two regions, we determine variability across renditions within individuals, and test whether phrases are randomly ordered and combined. We report three major findings. First, song phrases were highly stereotyped across two regions, so much so that some songs from the two colonies were almost indistinguishable. All males produced songs with the same four types of syllables and the same three types of phrases. Second, we found that although song construction was similar across regions, the number of syllables within phrases, and the number and order of phrases in songs varied greatly within and among individuals. Last, we determined that phrase order, although diverse, deviated from random models. We found broad scale phrase-order rules and certain higher order combinations that were highly preferred. We conclude that free-tailed bat songs are composed of highly stereotyped phrases hierarchically organized by a common set of syntactical rules. However, within global species-specific patterns, songs male free-tailed bats dynamically vary syllable number, phrase order, and phrase repetitions across song renditions

The Neural Substrates of Infant Sleep in Rats

Sleep is a poorly understood behavior that predominates during infancy but is studied almost exclusively in adults. One perceived impediment to investigations of sleep early in ontogeny is the absence of state-dependent neocortical activity. Nonetheless, in infant rats, sleep is reliably characterized by the presence of tonic (i.e., muscle atonia) and phasic (i.e., myoclonic twitching) components; the neural circuitry underlying these components, however, is unknown. Recently, we described a medullary inhibitory area (MIA) in week-old rats that is necessary but not sufficient for the normal expression of atonia. Here we report that the infant MIA receives projections from areas containing neurons that exhibit state-dependent activity. Specifically, neurons within these areas, including the subcoeruleus (SubLC), pontis oralis (PO), and dorsolateral pontine tegmentum (DLPT), exhibit discharge profiles that suggest causal roles in the modulation of muscle tone and the production of myoclonic twitches. Indeed, lesions in the SubLC and PO decreased the expression of muscle atonia without affecting twitching (resulting in “REM sleep without atonia”), whereas lesions of the DLPT increased the expression of atonia while decreasing the amount of twitching. Thus, the neural substrates of infant sleep are strikingly similar to those of adults, a surprising finding in light of theories that discount the contribution of supraspinal neural elements to sleep before the onset of state-dependent neocortical activity