Life Stage, Gender and Movement of Blue Crabs (Callinectis sapidus) in Lake Mattamuskeet and Connecting Canals

In their ranges on east and south coasts of the Americas as well as their established invasions in the Adriatic and Baltic, blue crabs, Callinectis sapidus, inhabit estuaries, sounds and coastal oceans and are commercially and ecologically important. How crabs move in response to physical variables is important to management. We monitored life stages at canal control structures, assessed gender ratios with recreational crabbing, learned from crabbers, and studied movements of tagged crabs in a canal connecting Lake Mattamuskeet to the Pamlico sound.  Juveniles enter the lake  through two of 4 canals connecting to the sounds.  Females migrate out through one canal. The lake standing population is about 70% male.  Movements of 240 crabs in August 2012 and 102 crabs in October 2014 were quantified using RFID tags with co-located meteorological and oceanographic devices. Non-spawning females and males are nomadic.  Crabs released in the canal move in response to changes in water depth and go with the flow, toward the Pamlico Sound (summer 76% and fall 78%). What crabbers describe as a fall migration  appears to be concentration of crabs in warmer deeper canals and then southern movement with flow generated by strong north winds. To be effective, management strategies like migratory corridors require understanding of crab movements

Effect of temperature on small-scale deformation of individual face-centered-cubic and body-centered-cubic phases of an Al_(0.7)CoCrFeNi high-entropy alloy

High-entropy alloys (HEAs) represent an important class of structural materials because of their high strength, ductility, and thermal stability. Understanding the mechanical response of isolated phases of a FCC/BCC dual-phase HEA is integral to understanding the mechanical properties of these alloys in the bulk. We investigate the compressive response of single-crystalline cylinders with diameters between 400 nm and 2 μm excised from individual grains within FCC and BCC phases of the dual-phase Al_(0.7)CoCrFeNi HEA at 295 K, 143 K, and 40 K. We observed a “smaller is stronger” size effect in the yield strength as a function of pillar diameter, D, of both alloy phases for all temperatures, with a power-law exponent, m, decreasing with temperature for the FCC phase, and remaining constant for all temperatures in the BCC phase. We found reduced work-hardening rates and more extensive strain bursts during deformation at lower temperatures in all samples. We performed molecular dynamics simulations of similar FCC and BCC HEA compression that displayed deformation dominated by dislocation slip at all temperatures. We discussed theories of low-temperature strengthening in HEAs, compared them to our experimental data and assessed how they manifest in the observed temperature-dependent size effect and work-hardening

Acute social isolation alters neurogenomic state in songbird forebrain

Prolonged social isolation has negative effects on brain and behavior in humans and other social organisms, but neural mechanisms leading to these effects are not understood. Here we tested the hypothesis that even brief periods of social isolation can alter gene expression and DNA methylation in higher cognitive centers of the brain, focusing on the auditory/associative forebrain of the highly social zebra finch. Using RNA sequencing, we first identified genes that individually increase or decrease expression after isolation and observed general repression of gene sets annotated for neurotrophin pathways and axonal guidance functions. We then pursued 4 genes of large effect size: EGR1 and BDNF (decreased by isolation) and FKBP5 and UTS2B (increased). By in situ hybridization, each gene responded in different cell subsets, arguing against a single cellular mechanism. To test whether effects were specific to the social component of the isolation experience, we compared gene expression in birds isolated either alone or with a single familiar partner. Partner inclusion ameliorated the effect of solo isolation on EGR1 and BDNF, but not on FKBP5 and UTS2B nor on circulating corticosterone. By bisulfite sequencing analysis of auditory forebrain DNA, isolation caused changes in methylation of a subset of differentially expressed genes, including BDNF. Thus, social isolation has rapid consequences on gene activity in a higher integrative center of the brain, triggering epigenetic mechanisms that may influence processing of ongoing experience.Peer reviewe

Reporting of Concussion Symptoms By a Nationwide Survey of United States Parents of Middle School Children

This cross-sectional study assessed concussion symptom knowledge of parents of middle school (MS) children (aged 10–15 years) through a free-response item that solicited concussion symptoms and compared findings to a pre-validated scale-based measure. A self-administered online questionnaire was sent to a panel of randomly selected United States residents who were recruited by a third-party company, aged ≥ 18 years, and identified as parents of MS children. Via a free-response item, parents listed what they believed were concussion symptoms. Multiple sections later, parents identified potential concussion symptoms via a scale measure, which featured 25 items (22 actual symptoms, three distractor symptoms) with three response options: yes, no, maybe. Free-response item responses were coded into specific symptoms. The 1062 eligible parents that provided complete data commonly identified the symptoms of dizziness (90.2%), blurred vision (87.4%), and balance problems (86.4%) on the scale-based measure. However, these and other symptoms were less commonly identified via the free-response item (dizziness: 44.4%; blurred vision: 16.5%; balance problems: 3.5%). Concussion symptoms commonly reported via the scale-based measure were reported less frequently within the free-response item. Future research must explore strategies to help clinicians working with parents and their children to measure and assess concussion symptom reporting and knowledge

Renal Hemodynamics During Sympathetic Activation Following Aerobic and Anaerobic Exercise

We tested the hypotheses that prior aerobic (Study 1) or anaerobic (Study 2) exercise attenuates the increase in renal vascular resistance (RVR) during sympathetic stimulation. Ten healthy young adults (5 females) participated in both Study 1 (aerobic exercise) and Study 2 (anaerobic exercise). In Study 1, subjects completed three minutes of face cooling pre- and post- 30 min of moderate intensity aerobic exercise (68 ± 1% estimate maximal heart rate). In Study 2, subjects completed two minutes of the cold pressor test pre- and post- the completion of a 30 s maximal effort cycling test (Wingate Anaerobic Test). Both face cooling and the cold pressor test stimulate the sympathetic nervous system and elevate RVR. The primary dependent variable in both Studies was renal blood velocity, which was measured at baseline and every minute during sympathetic stimulation. Renal blood velocity was measured via the coronal approach at the distal segment of the right renal artery with pulsed wave Doppler ultrasound. RVR was calculated from the quotient of mean arterial pressure and renal blood velocity. In Study 1, renal blood velocity and RVR did not differ between pre- and post- aerobic exercise (P ≥ 0.24). Face cooling decreased renal blood velocity (P < 0.01) and the magnitude of this decrease did not differ between pre- and post- aerobic exercise (P = 0.52). RVR increased with face cooling (P < 0.01) and the extent of these increases did not differ between pre- and post- aerobic exercise (P = 0.74). In Study 2, renal blood velocity was 2 ± 2 cm/s lower post- anaerobic exercise (P = 0.02), but RVR did not differ (P = 0.08). The cold pressor test decreased renal blood velocity (P < 0.01) and the magnitude of this decrease did not differ between pre- and post- anaerobic exercise (P = 0.26). RVR increased with the cold pressor test (P < 0.01) and the extent of these increases did not differ between pre- and post- anaerobic exercise (P = 0.12). These data indicate that 30 min of moderate intensity aerobic exercise or 30 s of maximal effort anaerobic exercise does not affect the capacity to increase RVR during sympathetic stimulation following exercise

Thermochemistry, Morphology, and Optical Characterization of Germanium Allotropes

A thermochemical study of three germanium allotropes by differential scanning calorimetry (DSC) and oxidative high-temperature drop solution calorimetry with sodium molybdate as the solvent is described. Two allotropes, microcrystalline allo-Ge (m-allo-Ge) and 4H-Ge, have been prepared by topotactic deintercalation of Li_7Ge_(12) with methanol (m-allo-Ge) and subsequent annealing at 250 °C (4H-Ge). Transition enthalpies determined by differential scanning calorimetry amount to 4.96(5) ± 0.59 kJ/mol (m-allo-Ge) and 1.46 ± 0.55 kJ/mol (4H-Ge). From high-temperature drop solution calorimetry, they are energetically less stable by 2.71 ± 2.79 kJ/mol (m-allo-Ge) and 5.76 ± 5.12 kJ/mol (4H-Ge) than α-Ge, which is the stable form of germanium under ambient conditions. These data are in agreement with DSC, as well as with the previous quantum chemical calculations. The morphology of the m-allo-Ge and 4H-Ge crystallites was investigated by a combination of scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. Even though the crystal structures of m-allo-Ge and 4H-Ge cannot be considered as truly layered, these phases retain the crystalline morphology of the layered precursor Li_7Ge_(12). Investigation by diffuse reflectance infrared Fourier transform spectroscopy and UV–vis diffuse reflectance measurements reveal band gaps in agreement with quantum chemical calculations

Militarization and social development in the Third World

In this study we integrated the modernization and dependency theories of development to suggest the ways whereby militarization can affect development. We examined the effects of three components of militarization highlighted in these theories on the social development of ninety-two developing countries. Overall, our findings support the dependency theory's emphasis on the detrimental impact of international trade on disadvantaged nations. There is a significant negative correlation between arms import and social development. Arms export and indigenous spending are correlated with social development in the expected directions but their beta coefficients are not significant. The diverse ways these three aspects of militarization have been shown to affect social development help to explain some of the conflicting findings in the literature and point to the need to study these variables in their disaggregated form.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69141/2/10.1177_144078339503100105.pd

Izu-Bonin-Mariana Rear Arc: The Missing Half of the Subduction Factory

4GT) lies in the western part of the Izu fore-arc basin, ~60 km east of the arc-front volcano Aogashima, ~170 km west of the axis of the Izu-Bonin Trench, 1.5 km west of Ocean Drilling Program (ODP) Site 792, and at 1776 meters below sea level (mbsl). It was drilled as a 150 m deep geotechnical test hole for potential future deep drilling (5500 meters below seafloor [mbsf]) at proposed Site IBM-4 using the D/V Chikyu. Core from Site U1436 yielded a rich record of Late Pleistocene explosive volcanism, including distinctive black glassy mafic ash layers that may record large-volume eruptions on the Izu arc front. Because of the importance of this discovery, Site U1436 was drilled in three additional holes (U1436B, U1436C, and U1436D), as part of a contingency operation, in an attempt to get better recovery on the black glassy mafic ash layers and enclosing sediments and to better constrain the thickness of the mafic ash layers. IODP Site U1437 is located in the Izu rear arc, ~330 km west of the axis of the IzuBonin Trench and ~90 km west of the arc-front volcanoes Myojinsho and Myojin Knoll, at 2117 mbsl. The primary scientific objective for Site U1437 was to characterize “the missing half of the subduction factory”; this was because numerous ODP/Integrated Ocean Drilling Program sites had been drilled in the arc to fore-arc region (i.e., ODP Site 782A Leg 126), but this was the first site to be drilled in the rear part of the Izu arc. A complete view of the arc system is needed to understand the formation of oceanic arc crust and its evolution into continental crust. Site U1437 on the rear arc had excellent core recovery in Holes U1437B and U1437D, and we succeeded in hanging the longest casing ever in the history of R/V JOIDES Resolution scientific drilling (1085.6 m) in Hole U1437E and cored to 1806.5 mbsf