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Small-particle analysis is a highly promising emerging forensic tool for analysis of interdicted special nuclear materials. Integration of microstructural, morphological, compositional, and molecular impurity signatures could provide significant advancements in forensic capabilities. We have applied rapid, high-sensitivity, hard X-ray synchrotron chemical imaging to analyze impurity signatures in two differently fabricated fuel pellets from the 5th Collaborative Materials Exercise (CMX5) of the IAEA Nuclear Forensics International Working Group. The spatial distributions, chemical compositions, and morphological and molecular characteristics of impurities were evaluated using X-ray absorption near-edge structure (XANES) and X-ray fluorescence chemical imaging to discover principal impurities, their granularity, particle sizes, modes of occurrence (distinct grains vs incorporation in the UO

Approaches to treating heart failure (HF), understanding of the most timely and effective interventions, and identification of appropriate patient subpopulations must evolve. HF has emerged as a chronic condition that needs to be managed on multiple fronts. Hospital resources are more limited than ever due to various factors that directly impact staff and hospital space available to manage and treat patients with HF. As a result, there is increasing attention to the current state of this progressive disease and ways to improve patient outcomes.This paper examines HF and the current and future treatment landscape, the need to reevaluate terms and definitions, and the opportunity to treat HF with the right treatment at the right time. Treatments in development and potential new investigational therapies are also discussed.To meet the current challenge, HF treatment must adapt. For other disease states, we have more personalized, nimble, and timely treatment strategies that harness windows of opportunity to help maximize outcomes and reduce overwhelming costs to the health care system. HF treatment is evolving with new guidelines and treatments that hold the promise of greater personalization through additions to existing treatments that are directed by medical guidelines, since each patient is unique and requires more than a one-size-fits-all approach. In addition, advances in remote monitoring, in-home care, and telemedicine are creating a more individualized treatment approach. Therefore, it becomes critical for all health care decision makers to be aware of the tools and resources available in treatment guidelines, individualized treatment options, telemedicine, and other ways of expanding the existing toolbox to enhance patient centricity in HF treatment.

Across animal taxa, individuals eavesdrop upon courting conspecific males, often in an attempt to steal mating opportunities. While multimodal signals can increase the likelihood that choosers respond to courters, such multimodal signals might also attract the unwanted attention of conspecific eavesdroppers. Previous studies of the brush-legged wolf spider, Schizocosa ocreata, demonstrate that field-experienced males court in response to visual displays of conspecific male courtship more than do laboratory-raised males. Furthermore, other studies demonstrate that males can learn to associate visual signals with the presence of a nearby female. Male S. ocreata, however, use a combination of vibratory and visual signals in their multimodal courtship display. Whether such associative learning varies based on which signal modality is experienced or whether multimodal signals result in enhanced learning remains unknown. Consequently, we examined eavesdropping on courtship behaviours of S. ocreata, with added emphasis on learning to respond to unimodal versus multimodal playback. We used vibratory and video playback techniques to test whether associative learning results in varied courtship levels when males associate unimodal or multimodal courtship signals with the presence of a nearby female. Results show that male S. ocreata associated courtship playback with the presence of a nearby female (i.e. courted at higher levels), regardless of whether courtship playback was unimodal or multimodal, demonstrating that male S. ocreata are capable of learning in multiple modalities. Multimodal playback, however, did not appear to enhance males’ ability to associate conspecific courtship signals with female cues. Courtship behaviours were greater in response to vibratory playback, though, suggesting that male S. ocreata weight modalities differently than females do. We further discuss the implications of this result regarding the communication network of S. ocreata.

Behavioral biologists have long been fascinated with the diversity of animal signals produced in the contexts of courtship and same-sex competition. In these contexts many lizards engage in conspicuous bobbing displays, and numerous studies have been devoted to describing these displays. Traditionally, bobbing displays are partitioned into units whose durations (and sometimes head amplitudes) are measured. Recently, Macedonia et al. (2019) introduced use of the Discrete Fourier Transform (DFT) as an alternative to unit-based variables for characterizing species-specific traits in display structure of Galapagos Lava Lizards (Microlophus spp.). The relative success of the two methods was not compared directly, however, because the homology of display units among species was uncertain. Here we overcome this problem using the “grahami series” of Anolis lizards—a monophyletic radiation of seven species on Jamaica and Grand Cayman. Our study had three primary goals. Our first goal was to discover whether DFT-based measures, unit-based measures, or their combination provided the best means to capture taxon-specific distinctiveness in display structure. To this end, we quantified bobbing displays and used nested analyses of variance (ANOVAs) to determine if particular variables were reliably superior at differentiating populations within a species. We then used principal components analysis to reduce the number of measurement variables, and entered the components into discriminant function analyses to determine which approach best discriminated among taxa. Results showed that no one type of measurement, or measurement combination, emerged as being consistently better at discriminating taxa across comparisons. Our second goal was to test a hypothesis that arose from our findings in Galapagos Lava Lizards—that the DFT may decrease in effectiveness as bobbing display structure increases in complexity. For this test we used four simple and compound display types from the species Anolis reconditus. Results of discriminant function analyses provided mixed support for the hypothesis, and we suggest that a definitive test of DFT performance and display complexity should utilize synthetic displays in which attributes of display structure are varied systematically. Last, we show how bobbing display structure maps onto alternative DNA-based phylogenies of the grahami series anoles. Whereas some species produced derived display types unanticipated from displays of more basal species in this adaptive radiation, others exhibited features that linked them to a particular population of a species in their clade.

As a propaedeutic towards what I want eventually to call “a theory of the corpse,” my essay briefly considers images of Romantic remains—in particular, figures of desecrated, diminished, scorned, h...

Invasive species are a world-wide threat to biodiversity. Yet, our understanding of biological invasions remains incomplete, partly due to the difficulty of tracking and studying behavioural interactions in recently created species interactions. We tested whether the interactions between the recently introduced invasive lizard Anolis cristatellus and the native Anolis oculatus in Dominica have led to changes in species recognition and aggressive behaviour of the native species. The use of realistic robots allowed us to test the behavioural response of 131 A. oculatus males towards relevant and controlled conspecific versus heterospecific stimuli, directly in the field and in two contexts (allopatry vs. sympatry). Our results show that species recognition evolved prior to sympatry in A. oculatus. Moreover, interspecific competition resulted in an increase in the time spent displaying and a divergence in the aggressive behaviour of the native species towards conspecifics versus heterospecifics. Inherent species recognition and higher aggressive behaviour may limit species coexistence as they are expected to favour A. oculatus during territorial interactions with A. cristatellus. While more studies are needed to understand the causes of these behavioural shifts and their consequences on long-term species coexistence, the present study highlights the role of behaviour as a first response to interspecific interactions.

Complex signals of animals involve multiple sensory modes and contain multiple structural components, and teasing apart how these modes and components interact in receiver decision making is an experimental challenge. Females of many species have ordered preferences for increased size or expression of male indicator traits. However, studies also suggest other species may exhibit comparative evaluation of mates rather than absolute preference hierarchies. We examined mate assessment by female wolf spiders, Schizocosa ocreata, using digital playback of video and vibratory/seismic signals in preference and choice tests of male trait differences. In playback experiments, female wolf spiders showed ordered preferences for male condition indicating traits (leg tuft size, vibration signal amplitude) in both individual sensory modes and multimodal (combined) signals. Tests with single modes and multimodal signals showed that trait expression in either signal mode affects outcome of mate choice. Females exhibited transitive preferences, consistently choosing males with larger tuft size or higher amplitude vibration in no-choice and two-choice tests. Thus, female S. ocreata do not necessarily need to compare mates to exhibit preferences for particular traits. Choice tests with multimodal playback showed that females made predicted choices when male traits covaried positively, but in ‘cue-conflict’ (negative trait covariance) choice tests, females showed a bias for visual signal trait expression (tuft size), displaying priority for visual signals over vibratory signals when in conflict. These studies demonstrate that under controlled experimental conditions, differences in behavioural responses to manipulation of digital video and vibration playback can provide valuable insights about recognition and interpretation of complex signals and their components.

The regulation of body temperature (Tb) is important for energy acquisition in ectotherms but may be challenging and costly. We studied the thermal biology of a north temperate population of Midland Painted Turtles (Chrysemys picta marginata) in a small pond in central Michigan. Cycling of mean daily body temperature (Tb) began as early as March and continued through October. The thermoregulatory setpoint range was 25–31°C, and turtles largely maintained Tb near or within the Tset range throughout the day between May and September. Mean hourly Tb was slightly (+0.5°C) higher on sunny days when compared to cloudy days. Turtles had relatively low investment in thermoregulation during the fall months potentially as an energy conservation measure prior to hibernation. Thermal exploitation values (Ex) indicated that our turtles spent as much, or more, time within the Tset range than individuals in other north temperate Painted Turtle populations and other reptile species studied to date, which was most likely ...

In many species, outcomes of male duels determine access to females and, ultimately, male reproductive success. Ritualization of behavior in male contests can reduce the probability of injury, which benefits both contestants. Components of ritualized combat often include postures and displays that showcase a male’s quality in a sequential assessment of fighting ability. Among the most common contest acts in iguanine lizards are bobbing displays. Investigations of bobbing display dynamics often include experimental “playbacks,” in which video or robotic representations of conspecifics are presented to subjects. In most “playback” research, pre-programmed stimuli exhibit behavior that is independent of subjects’ responses, despite the fact that actual animal contests are highly interactive. In the present study, we utilized a robotic Galapagos lava lizard (Microlophus bivittatus) to investigate the importance of interaction in simulated contests under field conditions. Using a matched pairs design where each subject experienced two behavioral variants of the robotic stimulus, we tested the effect of a robot that displayed immediately following a subject’s display versus when the same robot display was postponed 30 s. Results showed that immediate response from the robot stimulated subjects to display significantly more often than when the stimulus was delayed. We speculate that subjects perceived a rapid response from their robotic contestant as being more aggressive than a delayed response. We discuss our results in light of relevant previous work, and we suggest possibilities for future research using interactive lizard robots. Some of the most impressive examples of ritualized animal behavior can be observed in male contests for access to reproductive females. The use of stereotyped displays in such duels allows males to assess one another’s quality while avoiding dangerous fighting that can lead to injury. For example, males in many lizard species perform bobbing displays where contestants respond to each other in reciprocal fashion. In this study, we used a realistic lizard robot as a stand-in for a contestant in simulated contests. We found that an immediate display response by the robot to a subject’s bobbing display stimulated subjects to display significantly more often than when the robot’s response was delayed by 30 s. To our knowledge, this is the first interactive robot “playback” experiment with lizards. Future research will further explore the “rules” underlying display behavior in lizard contests.

Multimodal courtship signals may compensate for environmental interference or loss of signals in some sensory modes but may also increase detection by eavesdroppers. Studies on the wolf spider Schizocosa ocreata (Hentz) have demonstrated that males eavesdrop on visual courtship cues of other males and subsequently initiate courtship. Since S. ocreata males use multimodal courtship signals, we examined responses of males to playback of signals in different sensory modes (visual, vibration, multimodal) to test their relative importance for eavesdropping on courting male rivals. We used a recently developed technique to present male wolf spiders with video and/or vibratory stimuli: (1) a multimodal courting male stimulus, with synchronous visual and vibratory cues; (2) a visual-only courting male stimulus (minus the vibratory cues); (3) vibratory cues only (minus the visual cues); and (4) a control (visual background, no courtship). In single-presentation (no-choice) tests, males displayed more courtship bouts and longer durations of courtship bouts to the vibratory stimulus compared with either the visual or multimodal stimuli. However, in two-choice tests where isolated vibratory cues were paired against visual or multimodal stimuli, test males responded with more courtship bouts and longer durations of courtship bouts to the multimodal and visual stimuli. Results of these experiments suggest that male wolf spiders may vary eavesdropping courtship behaviors to compensate for missing sensory information concerning the location and other distinguishing characteristics of the rival male and the whereabouts of the female. Social eavesdropping is used to exploit information in signals of conspecifics, e.g., as a means of mate competition. Studies on Schizocosa ocreata wolf spiders have shown that males eavesdrop on visual courtship displays of other males and subsequently initiate multimodal courtship. We used video/vibration playback to examine responses of males to signals in different sensory modes (visual, vibration, both) and determine their relative importance for eavesdropping on courting male rivals. Results suggest that depending on sensory modes of their rivals’ signals, males may vary their own courtship displays to compensate for missing information. For example, when signals are presented individually, eavesdropping male response patterns are distinctly different from when presented a choice between modes. Males show more displays with isolated vibratory signals, but given a choice, males more often increase their tapping when multimodal cues were present. Ultimately, eavesdroppers that adjust behaviors in response to available sensory cues would be able to “level the playing field” with rivals and potentially increase the probability of gaining attention of females.

Early study of what is now called the Opohonga Limestone in west-central Utah indicated that it was part of a massive formation of Carboniferous age. Later studies identified fossils from the formation's older carbonates that were known to be Early Ordovician. A significant conodont fauna from a section on Gardison Ridge permits an even more precise definition of the formation which includes correlation with the classic North American Ibexian sequence of western Utah. While an important part of the earliest Ibexian sequence is missing on Gardison Ridge, the Opohonga Limestone there contains conodont elements representing seven zones and subzones of the type Ibexian and can be firmly correlated with conodont zones of the upper House and most of the Fillmore Formations of the Pogonip Group in the Ibex area. This correlation also confirms that the Sauk III–IV sequence boundary occurs in the lower part of the formation. The oldest conodont faunas of the Ibexian Series were not recovered from the lowe...

Males that search widely for females and perform conspicuous courtship displays run a high risk of being detected by their predators. Therefore, gains in reproductive success might be offset by increased mortality due to predation. Male brush-legged wolf spiders (Schizocosa ocreata) with larger decorative traits (foreleg tufts) are preferred by females as mates, but are more readily detected by predators. However, predation risk may also be influenced by the interaction between components of signals and the environment in which signaling occurs. Courting male spiders were readily accepted as prey by a sympatric predator, the American toad (Anaxyrus americanus). We used video playback to tease apart the interactive effect between visual signals and the signaling environment on the ability of toads to detect courting spiders as a function of distance, background contrast, the presence or absence of male foreleg tufts, and behavioral activity. The response of toads to video sequences of male spiders was similar to their response to live male spiders. Toad response varied over distance toward spiders displayed against high contrast (sunny) vs. low contrast (shaded) backgrounds. Beyond 30 cm, more toads detected courting male spiders against light, ‘sunny’ backgrounds and detected them faster when compared to the same spider stimulus against darker, ‘shady’ backgrounds. In choice tests, toads oriented more often toward courting males with leg tufts than those without. Toad responses also varied with male spider behavior in that only videos of moving males were attacked. Latency to orient and detection by toads was significantly greater for walking males than courting males, and this effect was most evident at distances between 30 cm and 50 cm. Results supported that courting wolf spiders are at significant risk of predation by visually acute predators. Distance, background contrast, and the presence of foreleg decorations influence detection probability. Thus, the same complex visual signals that make males conspicuous and are preferred by females can make males more vulnerable as prey to toads.

Thermal biology, and therefore energy acquisition and survival, of ectotherms can be affected by diel and seasonal patterns of environmental temperatures. Galapagos Lava Lizards live in seasonal environments that are characterized by a warm and wet period when reproductive activity is maximal, and cooler and drier period. With the use of radiotelemetric techniques to record lizard surface temperatures (Ts), we studied the thermal ecology of the San Cristobal Lava Lizard (Microlophus bivittatus) during both the warm and cool seasons over two years. During the diel activity period and when operative temperatures exceeded Tset-min, at least on rock faces without canopy, 52% or less of the Ts observations fell within the laboratory-determined Tset range (36–40 °C). Therefore, lizards may have avoided very warm midday temperatures in shaded microhabitats and the lag times in changes in Ts values occurred as operative temperatures rose rapidly during late morning warming phase. Lizards effectively thermoregulated during a year with moderate warm season temperatures and during a cool season that was unseasonably warm. In contrast, lizards less effectively thermoregulated during the warmest and coolest years of the study. We did not detect intersexual differences in thermoregulation although males may thermoregulate less effectively than do females during the cool season although we were unable to detect significant differences using our nonparametric statistical techniques.

Signalers must balance the benefits of detection by intended receivers with the costs of detection by eavesdroppers. This trade-off is exemplified by sexual signaling systems, in which signalers experience sexual selection for conspicuousness to mates as well as natural selection for crypsis to predators. In this study, we examined how courtship behavior and body coloration influenced the conspicuousness of males to avian predators in the well-studied brush-legged wolf spider system (Schizocosa ocreata (Hentz)). We focused on three behaviors (courtship, walking, and freezing) and two coloration schemes (natural coloration and idealized background-matching coloration). We presented captive blue jays (Cyanocitta cristata) with video playbacks of male spiders in a presence-absence detection task and characterized conspicuousness by measuring response latency and detectability. We found that any type of motion significantly increased detectability, and that body coloration and behavior interacted to determine detectability while the spiders were in motion. Among spiders in motion, courting spiders were detected faster than walking spiders. Stationary (frozen) spiders, in contrast, were rarely detected. These results illustrate that male S. ocreata can be both highly conspicuous and highly cryptic to avian predators. Thus, while we find that courtship is conspicuous to avian predators in this system, we suggest that behavioral plasticity may mitigate some of the predation costs of the sexual signal.

Differentiation in the structure of animal signals and displays among closely related species has intrigued biologists for centuries. Such divergence is often attributed to behavioural premating isolation, where sexual selection has favoured species recognition in environments containing sympatric congeners. However, in some cases closely related taxa have undergone speciation and display differentiation in isolation, in the apparent absence of benefits afforded by species recognition. Such is the case for the lava lizards (Microlophus spp.) endemic to the Galapagos Islands, where no two species overlap in distribution and all are thought to have evolved in allopatry from congeners. To test alternative evolutionary models, we used several phylogenetic comparative methods to assess how Microlophus displays have evolved. Results showed some potential for the influence of genetic drift, but little evidence of sexual selection (via male–male competition) or colonization history on the way displays have diverged among taxa. We then used lizard robots to test whether two representative Galapagos lava lizard species, Microlophus grayii and Microlophus indefatigabilis, would respond preferentially to a robot performing conspecific displays over those of the congener. We predicted that, in the absence of reinforcing selection, neither species would show a preference for conspecific displays. Results were mixed: whereas M. grayii showed no discrimination of conspecific over heterospecific displays, male M. indefatigabilis showed significantly stronger responses to their own displays than to those of the heterospecific. We then conducted the same experiment with a mainland congener, Microlophus occipitalis, to provide a broader view of potential responses across the group. Results revealed significant discrimination against heterospecific displays. We discuss our findings in light of hypotheses of signal differentiation, and suggest alternative interpretations for recognition of conspecific displays in species that are thought to have evolved in isolation.

When reproductive success is limited by mate search costs, males can reduce costs by eavesdropping and initiating displays if conspecific courtship is detected. Here, we examine eavesdropping by male Schizocosa ocreata wolf spiders, with field studies, laboratory studies using video playback and live exposure studies. In field enclosure experiments, introduced males responded with increased courtship signalling behaviour in the presence of a courting male. In the laboratory, field-collected males spent more time engaged in interaction behaviours and performed more bouts of courtship activity in response to a courting video male stimulus than did laboratory-reared males, suggesting that eavesdropping might arise as a consequence of field experience. To explore this further, we conducted associative learning studies on naive, laboratory-reared males, pairing video playback of male courtship with sensory cues indicating female presence. Results showed that males with no prior exposure learned to associate courtship of other males with cues indicating the presence of females. In subsequent video playback experiments, field-collected males recognized differences in male behaviour, responding with courtship more often and for longer periods to video stimuli of courting male spiders than to walking males or an empty leaf litter background (no spider). Additional studies showed that males spent significantly more time in courtship displays when presented with two to three live or video male stimuli simultaneously. Together, these findings confirm that male wolf spiders meet assumptions of eavesdropping behaviour, and suggest that social experience arising from exposure to courtship interactions of conspecifics may impact male eavesdropping and subsequent courtship behaviour.

Green Anoles (Anolis carolinensis) are comprised of red-dewlapped (RD) forms that are found throughout the southeastern USA and a gray-dewlapped (GD) form that is restricted to southwest Florida. Prior research has shown that RD A. carolinensis produce headbob displays of three distinct types that differ primarily in their temporal patterns. Based on known morphological, physiological, and genetic differences between GD and RD populations, we hypothesized that these populations also would differ in headbob display structure. To test this hypothesis we quantified 440 displays from 39 males (24 GD and 15 RD) and assigned displays to type using numerical decision criteria. Although comparison of the same display types between GD and RD males revealed differences in the durations of several homologous display units (i.e., bobs or interbob pauses), only one unit differed following statistical correction for multiple comparisons. By taking into account all display variation in both populations simult...

Understanding the nature of covalent (band-like) vs ionic (atomic-like) electrons in metal oxides continues to be at the forefront of research in the physical sciences. In particular, the development of a coherent and quantitative model of bonding and electronic structure for the lanthanide dioxides, LnO

Actinyl-tricarbonato anions [(AnO

The diverse colors of animals serve a variety of purposes, from acquiring mates to avoiding predators. Often, color patterns are not static throughout life, but change drastically during development, maturity, and senescence. While recent work has focused on the signaling value of vibrant colors in jumping spiders (Salticidae), we know very little about how colors change as spiders age; such information can provide a context for understanding the functions of and constraints on colorful traits. Focusing on Habronattus pyrrithrix Chamberlin 1924, our goals were to examine (1) the microscopic morphology of the colored body regions that males display to females during courtship (i.e., males' red faces, green legs, and white pedipalps), (2) how the colors of these regions as well as dorsal color patterns change during development prior to sexual maturity, and (3) how male condition-dependent red facial and green leg coloration changes as males age beyond sexual maturity. Although the bright white pedipalps and green legs of males appeared only upon sexual maturity, the sexes began to differentiate in facial coloration and dorsal patterning, with males developing red faces and conspicuous black and white dorsal patterning as young juveniles (ca. 2.5 mm in body length, or ca. 45% of their total mature adult body size). Even after maturity, color was not static; a male's green legs (but not red face) faded with age. Results are discussed in the context of potential functions of and constraints on color in salticids, and how they may change throughout an individual's lifetime.

In many animals, males display costly, condition-dependent ornaments to choosy females. Indicator models of sexual selection predict that females should choose mates based on natural variation in such traits. In Habronattus pyrrithrix jumping spiders, males have conspicuous, condition-dependent red faces and green legs that they display to cryptically coloured females during courtship. In a correlational study using field-collected spiders, we paired individual males with virgin females in the laboratory and found that natural variation in male coloration did not predict mating success (likelihood of copulation) or levels of female aggression. Rather, mating success was best predicted by male body condition. We then conducted an outdoor experiment under natural sunlight where we gave both virgin and mated females the choice between two simultaneously courting males, one with his facial coloration experimentally reduced and the other that received a sham treatment. Again, we found no relationship between male coloration and courtship success. Our previous studies have shown that the presence (versus absence) of red facial coloration improves courtship success, but here we found no evidence that more subtle natural variation in this trait has any effect on success. We discuss these findings in the context of complex signalling and species recognition in Habronattus. While many studies report negative results for condition-dependent quality signalling alongside positive ones, few discuss the implications of negative results. We argue that, as empirical data accumulate, we should move towards asking why some condition-dependent traits are consistently important to females while other equally condition-dependent traits are either ignored, or only matter in certain contexts.

Animal color signals evolve in response to selection by visual systems that perceive them, ambient light spectra that illuminate them, and features of the background against which they are juxtaposed. In Anolis lizards, males use a colorful dewlap, together with head-bobbing displays, to deter conspecific rivals and to attract females. As most anoles are both arboreal and sympatric with one or more congeners, selection should favor dewlap colors that contrast sufficiently with the visual background of foliage to be detectable, and that differ reliably from dewlaps of sympatric congeners to be discriminable. We used spectroradiometry and computational visual modeling for five species of closely related Jamaican anoles to calculate the detection probability of each species' dewlap in each of the species' light habitats. Despite substantial interspecific differences in dewlap colors, as well as moderate differences in habitat light spectra, results of our analyses did not support the prediction th...

In central Utah, the major pre-Mississippian unconformity is fairly well understood at most of the localities where it is recognized. However, the unconformity is more enigmatic in Rock Canyon of the central Wasatch Range. At this locality, dolomitization of most pre-Mississippian rocks obscures stratigraphic identification of Devonian and older units. The absence of any identifiable angular relationship further complicates resolution. Because of this, both identification of the stratigraphic level of the unconformity and, consequently, its magnitude remain controversial. Large-size dolomite samples taken in Rock Canyon at closely spaced intervals for the 3.6-m directly below definite Upper Devonian rocks yield microfossils, including conodonts, in the uppermost 1.6-m of that interval that indicate no unconformity exists between the Cambrian Maxfield Limestone and the Upper Devonian-Lower Mississippian Fitchville Dolomite at the horizon previously identified as unconformable. Rather, an unknown thickness of dolomitized Upper Devonian Pinyon Peak Formation and probable older rock (possibly Bluebell Dolomite and Victoria Formation) occurs between the top of definite Maxfield and base of the Fitchville. The identification of the unconformity horizon remains unknown. Our preliminary work outlines a promising procedure for future understanding of the magnitude and stratigraphic level of the unconformity.

The capacity for an ectothermic reptile to thermoregulate has implications for many components of its life history. Over two years, we studied thermoregulation in a population of Midland painted turtles (Chrysemys picta marginata) in a shallow, thermally variable wetland during summer in Northern Michigan. Mean body temperature (Tb) of free-ranging turtles was greater in 2008 (25.8 °C) than in 2010 (19.7 °C). Laboratory determined thermoregulatory set point (Tset) ranged from 25 °C (Tset-min) to 31 °C (Tset-max) and was lower during the fall (17–26 °C). Deviations of Tb distributions from field measured operative temperatures (Te) and indices of thermoregulation indicated that C. picta marginata were capable of a limited degree of thermoregulation. Operative temperatures and thermal quality (de=|Tset-min−Te| and |Te−Tset-max|) cycled daily with maximal thermal quality occurring during late morning and late afternoon. The accuracy of thermoregulation (db=|Tset-min−Tb| and |Tb−Tset-max|) was maximal (db values were minimal) as Tb declined and traversed Tset during the late afternoon–early evening hours and was higher on cloudy days than on sunny days because relatively low Te values decreased the number of Tb values that were above Tset. Our index of thermal exploitation (Ex=frequency of Tb observations within Tset) was 36%, slightly lower than that reported for an Ontario population of C. picta marginata. Regression of db (thermal accuracy) on de (thermal quality) indicated that turtles invested more in thermoregulation when thermal quality was low and when water levels were high than when they were low. There were no intersexual differences in mean Tb throughout the year but females had relatively high laboratory determined Tb values in the fall, perhaps reflecting the importance of maintaining ovarian development prior to winter.

Astronomical images are typically thought of as two-dimensional rectangular projections onto the celestial sphere. Such images may be defined by the right ascension (α) and declination (δ) of the four corners of the image, or by the α and δ of the image center, width and height of the image, and the rotation around the image center. The computations involved in determining the location of a moving object in relation to an image exposure involves several conversions of the object's position into observer centered α and δ as both the object and observer move over time. These conversions, although not complex, are computationally expensive as they involve trigonometric transformations. Since the position of an object is relative to the observer, there is little opportunity to optimize this heavy computation against multiple images, or against multiple image collections. The viewing frustum, the three-dimensional volume of space covered by an observer's view of a scene, is a long-used computer scene-rendering tool that allows world object positions to be transformed and clipped to a viewing port. This tool has been adapted to represent astronomical images as image frustums, supporting a one-time presearch optimization of individual image representations, while dramatically reducing object-image intersection detection complexity.

An animal’s coloration can be involved in communication and crypsis and change dynamically over time. We studied spectral reflectance of color pattern and substrate color-induced melanization in adult Midland Painted Turtles (Chrysemys picta marginata). Spectral reflectance of the carapace and plastron ground colors and of the red, yellow, and black markings of the head and limbs did not vary between the sexes. Therefore, yellow and red markings of the head and forelimbs seem unlikely to be sexually-selected traits as would be evidenced by differences in brightness between the sexes. Perhaps the color patterns of the head, neck, and shell margins function to break up the outline of an individual. However, we cannot rule out that the markings of the head and neck function in species recognition or evaluation of mate quality. After being laboratory reared for 150 days, the ground color and the spots or stripes of the head and limbs increased in intensity (turtles lightened) but more so in turtles reared on a white substrate when compared to those reared on a black substrate. At day 150, the ground colors of the carapace and plastron and the black blotches of the marginal scutes of the carapace were darker in individuals reared on a black substrate than in those reared on a white substrate. Therefore, adult turtles that travel among habitats with differing substrate colors could shift the degree of darkness of the carapace and skin ground color, thus more closely matching their backgrounds and reducing predation rates.

Some of the most striking behaviors of animals are displays used in courtship, territorial behavior, and in defense against predators. Among reptiles, lizards exhibit enormous diversity in...

Crypsis can be facilitated by dynamic color changes that are mediated by chromatophores of the integument. The histological bases of dynamic color changes are well understood for some reptiles, such as lizards, but less so for turtles. We used pixel counts from digital images of tail-tip sections to study histological changes that occur during substrate color-induced melanization, and reversal of melanization, in Midland painted turtles (Chrysemys picta marginata) during 2 companion studies. Melanization in C. picta marginata can be induced in light-skinned individuals when placed on a dark substrate and can be reversed in dark-skinned individuals when placed on a white substrate but without the shedding of scutes. Therefore, we predicted that color change would involve variations in intracellular melanosome concentrations within melanophores, in the deepest living epidermal cells, or both. At hatching, and in individuals that were reared on a white substrate, mean pixel density was relatively lo...

Multimodal signals may compensate for environmental constraints on communication, as signals in different modalities vary in efficacy. We examined the influence of complex microhabitats on transmission of vibratory and visual signals of courting male Schizocosa ocreata wolf spiders (Araneae: Lycosidae) with laser Doppler vibrometry (LDV) and behavioral observations in lab and field. We measured maximum potential detection distance of visual and vibratory signals by females in laboratory mesocosms, recorded vibration signal attenuation on different substrates, and estimated transmission distances for male vibration signals in the field. We also determined effective line-of-sight visual detection distances in the field with laser distance measures. Together, these data were used to estimate the potential and effective active space of multimodal signals. LDV measures show leaves are highly conductive substrates for wolf spider vibratory signals compared to others (soil, wood, rock). For both visual and vibratory modes, lab estimates of maximum potential distance for signal transmission and detection (behavior studies) exceeded estimates of effective active space (signal attenuation, “vanishing point,” and “line-of-sight” measures). Field estimates of transmission distance for signal modes overlap, such that in close range (

Male Anolis lizards exhibit an impressive diversity of dewlap color patterns and motion displays. These traits are thought to mediate species recognition, but direct experimental support is limited. It is also unclear if and how color and display behavior each may contribute to the signaling of species identity. We used a programmable robotic lizard to manipulate these signal components independently in Anolis grahami. Four robot variants were used: a control treatment that displayed the conspecific (orange) dewlap color and headbobbing sequence, 2 treatments that differed from the control only in dewlap coloration (light or dark blue), and a fourth treatment that differed from the control only in headbob display pattern (reversed headbob display structure). Artificial dewlaps were calibrated in color and brightness to the A. grahami visual system using a computational model. We presented robots to 102 adult male subjects and quantified their responses for durations of dewlap pulsing and headbob displays. Subjects spent significantly more time pulsing their dewlaps in response to control (conspecific) robot displays than to treatments that deviated from the control either in dewlap color or in headbob display structure. Our findings implicate both morphology and behavior as functional components of social signaling in A. grahami, thus underscoring the complex, multicomponent nature of anoline displays.

Clark meditates on the Spanish artist’s “unsparing vision of the degradation of humanity.” Clark not only revisits the images of humiliation, torture, and horror that engraved in this series, he asks what it means to “think Goya” today, a Goya who “imagines the worst and dwells with it.” Clark not only looks at the artist’s images but reads them, including the simple but arresting caption about seeing that Goya affixes to the engravings: “I saw it” (Yo lo vi). Clark’s Goya is the artist who not only confronts us with a horror to behold but who demands that we tarry uncomfortably with the images we behold and with the act of beholding. Clark concludes with a reflection on the notion of the political funeral of ACT UP as a form of mobilization profoundly proximate to the kind of thinking that Goya allows.