Lead-phase and Red-stripe Color Morphs of Red-backed Salamanders (Plethodon cinereus) Differ in Hematological Stress Indices: A Consequence of Differential Predation Pressure?

Throughout the animal kingdom there are species that have two or more phenotypic forms or ‘morphs’, and many of these are amphibians. In North America, the red-backed salamander Plethodon cinereus can have either a red dorsal stripe or no dorsal stripe (lead-phase form), and evidence to date indicates the lead-phase form incurs a greater number of attacks from predators. In a recent collection of 51 P. cinereus, blood smears of both color morphs (35 red-stripe, 16 lead-phase) were examined to obtain numbers of circulating leukocytes (via light microscopy), which can be used to indirectly estimate levels of stress hormones in vertebrates via a ‘hematological stress index’, which is the ratio between the number of two leukocyte types (neutrophils and lymphocytes). Our results showed that lead-phase salamanders tended to have greater numbers of circulating neutrophils and lower numbers of circulating lymphocytes than red-stripe morphs, leading to higher average neutrophil-lymphocyte ratios in lead-phase individuals. Since the salamanders were held (refrigerated) for 7 days before sampling, we cannot be certain if this effect is a stress reaction to the captivity or the normal level for this morph. However comparison with two sets of related salamanders that were captured and sampled immediately indicates the red-stripe salamanders were either not stressed from the captivity at all, or their white blood cell distributions had returned to normal after 7 days of captivity. Taken together, our results indicate that lead-phase forms of P. cinereus have higher stress levels than the red-stripe forms, which may be a consequence of their higher exposure to, and/or attacks from, predators. They may also indicate that the lead-phase form is less-suited to captivity than the red-stripe form of this species

Improving Natural History Research with Image Analysis: The Relationship Between Skin Color, Sex, Size and Stage in Adult Red-Spotted Newts

Natural history researchers are increasingly using digital cameras and computer software to measure their study animals. Adult Red-spotted Newts (Notophthalmus viridescens viridescens) are known to display a range of skin colors, from brown to green, but it has not been possible to quantify this variation until the advent of image analysis technology. We used an image analysis approach to compare skin color between sexes, across a range of sizes, and between aquatic and post-breeding (emigrating to the terrestrial habitat) stage adult newts. From 232 individuals (53% male, 47% female) we documented a wide but subtle range of skin colors, measured as the average hue value of all pixels in digital images of each newt body. We found that terrestrial post-breeding individuals were browner than aquatic individuals, consistent with the morphological adaptations of emigrating individuals for the terrestrial habitat. However, we also discovered that males were statistically greener than females but this effect depended on their stage. We suggest this difference may represent different degrees of adaptation for the terrestrial habitat between the sexes. Finally, we used image analysis to obtain measures of body length comparable to traditional snout-vent length and a measure of total body surface area, which provided a better correlation with newt mass than did body length and therefore could potentially serve as an alternative to mass or body condition. We suggest that image analysis methodology offers great promise for future questions relating to size and color in amphibians and provides researchers with an improved way to study aspects of the natural history of amphibians

Spots of Adult Male Red-Spotted Newts are Redder and Brighter than in Females: Evidence for a Role in Mate Selection?

As aquatic adults, eastern red-spotted newts (Notophthalmus v. viridescens) are generally green with two rows of dorsal spots, which vary in number between individuals and range in colour from orange to red. The function of these spots is unknown, but it is possible that they serve as sexual ornamentations and we examined this hypothesis by testing for sexual dimorphism in spot characteristics. We used an image analysis approach that has been used previously with this and other amphibian species to compare the number, size and colour – redness (hue score) and brightness – of spots in 100 male and 100 female aquatic adult newts captured during the breeding season in Virginia. While we found no apparent sex-related differences in the numbers of spots, and only a minor difference in spot sizes, we discovered that adult male red-spotted newts had significantly redder and more brightly coloured dorsal spots than did females. We also found that spot brightness is positively associated with body size. As male red-spotted newts entice females to mate in part with a highly visual display (the “hula dance”), the sexual dimorphism in spot colour we found could be associated with this display. Our results, taken together with current knowledge on the carotenoid pigments behind the red spot colour, suggest a role for spot coloration in the mating system of N. v. viridescens that should be examined further and considered in other studies of mate choice. In a more general sense, this discovery also leads us to question if this phenomenon is present in other amphibian species previously thought to be “monomorphic”

Detection of continuous variable entanglement without coherent local oscillators

We propose three criteria for identifying continuous variable entanglement between two many-particle systems with no restrictions on the quantum state of the local oscillators used in the measurements. Mistakenly asserting a coherent state for the local oscillator can lead to incorrectly identifying the presence of entanglement. We demonstrate this in simulations with 100 particles, and also find that large number fluctuations do not prevent the observation of entanglement. Our results are important for quantum information experiments with realistic Bose-Einstein condensates or in optics with arbitrary photon states.Comment: 7 Pages, 4 Figure

Wing Color of Monarch Butterflies ( Danaus plexippus

Monarch butterflies are famous among insects for their unique migration in eastern North America to overwinter sites in Mexico and their bright orange wing color, which has an aposematic function. While capturing migrating monarchs in northeast Georgia, USA, I noticed that many appeared to have unusually deep orange wings. I initiated the current study to compare wing hues (obtained using image analysis of scanned wings) of migrants (captured in 2005 and 2008) to samples of breeding and overwintering monarchs. Consistent with initial observations, migrants had significantly lower orange hues (reflecting deeper, redder orange colors) than breeding and overwintering monarchs. There was also a difference in hue between sexes and a relationship with wing size, such that larger monarchs had deeper, redder hues. The reasons for the color difference of migrants are not apparent, but one possibility is that the longer-lived migrant generation has denser scalation to allow for scale loss over their lifespan. Alternatively, this effect could be confined to the subpopulation of monarchs in the Southeastern United States, which may not be well represented at the Mexican overwintering sites. In any case, this discovery highlights the many questions emerging on the significance of wing color variation in this species

De novo Assembly and Analysis of the Northern Leopard Frog Rana pipiens Transcriptome

The northern leopard frog Rana (Lithobates) pipiens is an important animal model, being used extensively in cancer, neurology, physiology, and biomechanical studies. R. pipiens is a native North American frog whose range extends from northern Canada to southwest United States, but over the past few decades its populations have declined significantly and is now considered uncommon in large portions of the United States and Canada. To aid in the study and conservation of R. pipiens, this paper describes the first R. pipiens transcriptome. The R. pipiens transcriptome was annotated using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Eukaryotic Orthologous Groups (KOG). Differential expression analysis revealed universal and tissue specific genes, and endocrine-related genes were identified. Transcriptome assemblies and other sequence data are available for download

Our Comeback Story: Impostor Syndrome in the Archival Profession

In 2019, a group of archivists participated in two conference sessions focused on impostor syndrome in the archives field. Though no comprehensive study on impostor syndrome has been undertaken in the archives profession, the authors listened to numerous stories of the phenomenon among audience members. This perspectives article considers the presence and impact of impostor syndrome in the archives field. The authors define the phenomenon, review literature on its influences in the information science profession, include stories of archives professionals working with impostor syndrome, and offer suggestions for working through impostor syndrome

Blip glitches in Advanced LIGO data

Blip glitches are short noise transients present in data from ground-based gravitational-wave observatories. These glitches resemble the gravitational-wave signature of massive binary black hole mergers. Hence, the sensitivity of transient gravitational-wave searches to such high-mass systems and other potential short duration sources is degraded by the presence of blip glitches. The origin and rate of occurrence of this type of glitch have been largely unknown. In this paper we explore the population of blip glitches in Advanced LIGO during its first and second observing runs. On average, we find that Advanced LIGO data contains approximately two blip glitches per hour of data. We identify four subsets of blip glitches correlated with detector auxiliary or environmental sensor channels, however the physical causes of the majority of blips remain unclear