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We conducted aerial surveys of sea turtles in 2011 and 2012, incorporating corrections for perception and availability bias in Chesapeake Bay and near-shore continental shelf waters of the Mid-Atlantic Bight off the US states of Virginia and Maryland. Results of these surveys and ancillary research to determine surface times for loggerhead turtles provide us with a new baseline population estimate for turtles in the region. Prior surveys were conducted in Chesapeake Bay in the mid-1980s and early 2000s, and in ocean waters in the late 1970s and early 1980s. Although comparison of density estimates not corrected for availability between prior surveys and this effort suggests that the population of sea turtles, especially loggerhead turtles, is higher than previous estimates, differences between surveys may be the result of survey methodologies and cannot be assumed to be true changes in density. Surface time for availability corrections was calculated using dive summaries from satellite telemetry on 27 loggerhead turtles tracked between 2011 and 2015. We calculated stratified seasonal availability corrections for bay and ocean waters based on assumed differences in turtle behavior and water clarity between the 2 habitats. For each habitat, we provided seasonal corrections for 3 detection depth bins (shallow, moderate, and deep) to account for differences in sub-surface detection ranges. Differences and trends toward differences among availability corrections underscore the need to better understand the many variables that affect surface time for sea turtles in temperate waters, and the effect that availability has on abundance and density estimates.

Providing safe access to functional field experiences during the early stages of the COVID-19 pandemic was a distinct challenge. However, these experiences are critical to train students in ecological methods and provide an opportunity for open-ended, authentic research. Here, we report on a multiweek lab designed for an introductory ecology course, which was adapted for hybrid instruction during the pandemic. In the lab sequence, students independently surveyed basic phenological, population, and community dynamics of easily identifiable, cosmopolitan plant species in the genus "Plantago." Students used this crowd-sourced dataset to develop, analyze, and report on unique research questions regarding interactions between "Plantago" and the local environment. The new lab sequence effectively met course learning objectives in experimental design, field methods, statistics, and science communication, while being accessible to both in-person and online learners. We conclude by discussing the evolution of this design for other audiences.

The structures of three racemic (tetrahydro-[1,3]dioxino[5,4-d][1,3]dioxin-4-yl)methanol derivatives are reported, namely, 4-[(methylsulfonyloxy)methyl]-2,4,4a,6,8,8a-hexahydro-[1,3]dioxino[5,4-d][1,3]dioxine, C8H14O7S, 1, 4-[(benzyloxy)methyl]-2,4,4a,6,8,8a-hexahydro-[1,3]dioxino[5,4-d][1,3]dioxine, C14H18O5, 2, and 4-[(anilinocarbonyl)methyl]-2,4,4a,6,8,8a-hexahydro-[1,3]dioxino[5,4-d][1,3]dioxine, C14H17NO6, 3. Mesylate ester 1 at 173 K has triclinic P\overline{1} symmetry and both benzyl ether 2 at 173 K and phenyl urethane 3 have monoclinic P21/c symmetry. These structures are of interest because of the conformation of the cis-fused tetraoxadecalin ring system. This cis-bicyclo[4.4.0]decane ring system, i.e. cis-decalin, can undergo conformational equilibration. In the two most stable conformers, both six-membered rings adopt a chair conformation. However, there are significant consequences in these two stable conformers, with heteroatom substitution at the 1,3,5,7-ring positions as described. Only one conformation, denoted as `concave' or `inside', is found in these crystal structures. This is consistent with previously reported structures of the 1,1-geminal dihydroxy aldehyde and tosylate analogs.

Many studies of animal and plumage coloration use spectrometry to obtain objective measurements of colorful traits. Objective measurements of plumage color are particularly important as the avian visual system is distinct from our own and subjective color assessment by researchers can miss important color variation or signals. As spectrometry has become one of the preferred methods of color measurement, appropriate methodologies and reporting standards have refined and improved the technique as well as increased our ability to make comparisons across studies. Here, we investigate another important methodological decision by examining how the background color against which feather samples are measured impacts the reflectance spectra and color descriptors commonly extracted from those spectra. We used feather samples collected from Eastern Bluebirds (Sicilia siulis) and Barn Swallows (Hirundo rustica erythrogaster) to determine how black and white backgrounds influence color measurements. We measured the same feather sample in the same arrangement against a white index card and a piece of black cardstock and found that measurements taken against a white background tended to yield higher reflectance curves, which also resulted in significant differences in some color descriptors. Lightly colored, wispy, and small feathers seem to be particularly susceptible to background color effects. Thus, researchers using spectrometry to measure colorful traits should carefully consider the background against which they are taking measurements as white backgrounds tend to increase reflectance and certain feather colors or morphology (light and wispy) may be particularly susceptible to spectral contamination. Received 26 May 2022. Accepted 28 December 2022. Key words: animal coloration, color measurement, methods, plumage coloration, reflectance, spectrometry. Muchos cstudios sobre coloracion animal y del plumaje utilizan la espectrometria para obtener medidas objetivas de rasgos de color. Las medidas objetivas del color del plumaje son particularmente importantes debido a que el sistema visual de las aves es distinlo del nuestro y la evaluacion subjetiva del color por parte de los investigadores puede omitir algunas variaciones importantes del color o en senates de color. A medida que la cspectrometria se ha convcrtido en uno de los metodos preferidos para medir el color, las metodologias apropiadas y los estandares para reportarlo se han ido refinando y mejorando su teenica. ademas de incrementar nuestra capacidad para realizar comparaciones entre estudios. En este trabajo investigamos otra decision metodologica importante a la hora de examinar como el color del fondo contra el que se miden las muestras de afecta el espectro de reflectancia y a los descriptores de color comunmente extraidos de dichos espectros. Usamos muestras de plumaje recolectadas de azulejos (Sialia sialis) y golondrinas (Hirundo rustica erythrogaster) para determinar como un fondo blanco y uno negro influyen en las medidas de color. Medimos la misma muestra de plumas en la misma disposicion contra una tarjeta de cartulina blanca y una tarjeta negra. y encontramos que las medidas tomadas contra un fondo bianco tendian a producir curvas de reflectancia mas altas, lo que tambien produjo diferencias significativas en los descriptores de color. Las plumas pequenas. delgadas y de colores claros parecen ser particularmente susceptibles a los efectos del color del fondo. Por lo tanto, los investigadores que utilizan la cspectrometria para medir rasgos de color deben considerar con cuidado el fondo contra el cual estan tomando medidas, debido a que los fondos blancos tienden a aumentar la reflectancia y ciertos colores o morfologias (ligeras y tenues) de plumas pueden ser particularmente susceptibles a la contamination espectral. Palabras clave: coloracion animal, coloracion del plumaje, espectrometria. medicion del color, metodos. reflectancia., As spectrometers have become more affordable and portable, their use has become ubiquitous in animal coloration research, and particularly so in studies of plumage coloration. Spectrometers are powerful tools in [...]

Non-invasive methods such as Transcranial Magnetic Stimulation (TMS) and magnetoencephalography (MEG) aid in the pre-surgical evaluation of patients with epilepsy or brain tumor to identify sensorimotor cortices. MEG requires sedation in children or patients with developmental delay. However, TMS can be applied to awake patients of all ages with any cognitive abilities. In this study, we compared the efficacy of TMS with MEG (in awake and sedated states) in identifying the hand sensorimotor areas in patients with epilepsy or brain tumors. We identified 153 patients who underwent awake- (n = 98) or sedated-MEG (n = 55), along with awake TMS for hand sensorimotor mapping as part of their pre-surgical evaluation. TMS involved stimulating the precentral gyrus and recording electromyography responses, while MEG identified the somatosensory cortex during median nerve stimulation. Awake-MEG had a success rate of 92.35 % and TMS had 99.49 % (p-value = 0.5517). However, in the sedated-MEG cohort, TMS success rate of 95.61 % was significantly higher compared to MEG’s 58.77 % (p-value = 0.0001). Factors affecting mapping success were analyzed. Logistic regression across the entire cohort identified patient sedation as the lone significant predictor, contrary to age, lesion, metal, and number of antiseizure medications (ASMs). A subsequent analysis replaced sedation with anesthetic drug dosage, revealing no significant predictors impacting somatosensory mapping success under sedation. This study yields insights into the utility of TMS and MEG in mapping hand sensorimotor cortices and underscores the importance of considering factors that influence eloquent cortex mapping limitations during sedation.

Abstract Cetaceans have shown a potential to be used as sentinel species for tracking environmental change in marine ecosystems, yet our assessment of change is typically limited to recent decades and lacks ecological baselines. Using historical museum specimens, we compared community niche metrics and degree of individual dietary specialization in groups of Pacific Arctic beluga (Delphinapterus leucas) from the 1800s (n = 5) to 1900s (n = 10) using stable carbon and nitrogen isotopes drilled from teeth. Beluga occupied a broader trophic niche and demonstrated a higher degree of individual specialization in the 1800s than in the 1900s. The cause of this shift is difficult to confirm given long timescales and constraints of specimen‐based research but could indicate changes in the prey base or competition. The scale and nature of this detected shift provide perspective for continued research on these climate‐vulnerable species.

Julia Prest's book, "Public Theatre and the Enslaved People of Colonial Saint-Domingue," offers new insights into the history of slavery and enslaved individuals in eighteenth-century Saint-Domingue. The book examines the role of public theaters in displaying, resisting, and denying the violence of slavery. Prest's interdisciplinary approach draws on diverse fields and analyzes a range of sources, including theatrical works, performance records, newspapers, and legal documents. The book highlights the presence and contributions of enslaved people in the theater, complicating the narrative of white enslavers as the sole participants. Prest's work encourages further research and opens up new avenues for studying theater in French colonies and the francophone world. [Extracted from the article]

The spindle segregates chromosomes at cell division, and its task is a mechanical one. While we have a nearly complete list of spindle components, how their molecular-scale mechanics give rise to cellular-scale spindle architecture, mechanics, and function is not yet clear. Recent in vitro and in vivo measurements bring new levels of molecular and physical control and shed light on this question. Highlighting recent findings and open questions, we introduce the molecular force generators of the spindle, and discuss how they organize microtubules into diverse architectural modules and give rise to the emergent mechanics of the mammalian spindle. Throughout, we emphasize the breadth of space and time scales at play, and the feedback between spindle architecture, dynamics, and mechanics that drives robust function.