Movement of Red Snapper, Lutjanus campechanus, in the North Central Gulf of Mexico: Potential Effects of Hurricanes

Site fidelity and movement of red snapper, Lutjanus campechanus, were estimated from a tagging study conducted off the coast of Alabama from March 1995 to January 1997. Red snapper were caught using rod and reel over nine artificial reef sites, with three reefs each located at 21-m, 27-m, and 32-m depths. During the study, 1,604 fish were tagged, and 174 recaptures were made of 167 individuals. On 4 October 1995, the eye of Hurricane Opal passed within 40 km of the artificial reef sites. When recaptures were stratified according to whether or not they were at liberty during Opal, storm effect was the most significant factor in predicting the likelihood of movement and magnitude of movement by tagged red snapper. Eighty percent of recaptured red snapper that were not at liberty during Opal were recaptured at their site of release. Fish that were at liberty during Opal, however, had a significantly higher likelihood of movement away from their site of release (P \u3c 0.001). These fish also moved significantly further than those that were not at liberty during Opal (P \u3c 0.001). Fish that were at liberty during Opal moved a mean distance (± SE) of 32.6 km (± 6.81), compared to a mean distance (± SE) of 2.5 km (± 1.10) for fish that were tagged and recaptured before Opal, and a mean distance (± SE) of 1.7 km (± 0.43) for fish that were tagged and recaptured after Opal. Heretofore, it has generally been accepted that adult red snapper demonstrate strong site fidelity and genetic homogeneity in the stock was hypothesized to result from larval drift or due to historic mixing on longer time scales. This study documents movement of adult red snapper on spatial scales that would facilitate stock mixing and implicates large-scale climatic events, such as hurricanes, as important factors in stock mixing dynamics

Thermal gradient strategy to improve seeding for high rate zero excess lithium metal batteries

Zero excess lithium metal batteries (LMBs) have traditionally suffered from short cycle life due to nonuniform processes that result in parasitic side reactions and a subsequent loss of lithium inventory and electrolyte. The experiments herein demonstrate that zero excess LMB cells cycled with a low thermal average and thermal gradient outperform cells cycled under isothermal conditions during early cycles. Specifically, a low thermal average of ∼6.4°C and thermal gradient of 4C) and mismatched charge/discharge rates. Optimal cycling behavior was observed with 2C charging (30 min) and 3C discharging (20 min). These advantages were translated to the system relevant form factor-pouch cell (20X capacity). Based on the performance enhancement observed with extended application of a thermal gradient, we demonstrate the use of the environment as a formation strategy, to perpetuate improved plating in stripping over the cycle life of zero excess LMBs operating in ambient conditions.This article is published as Raj, Abhi, Robert W. Atkinson III, Todd A. Kingston, Rachel Carter, and Corey T. Love. "Thermal gradient strategy to improve seeding for high rate zero excess lithium metal batteries." Frontiers in Energy Research 12 (2024): 1327955. doi: https://doi.org/10.3389/fenrg.2024.1327955. © 2024 Raj, Atkinson, Kingston, Carter and Love. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)

From Carriage Wheels to Interest Rates: The Evolution of Word Problems in Algebra Textbooks from 1901 to Today

In teaching algebra, extra-mathematical word problems can bridge the gap between questions about abstract numbers and questions about everyday life. Thus, more than other aspects of elementary algebra, we would expect word problems to have changed in the recent past. This paper documents the findings of a collective research project that examined the content of such word problems over the past century. Alongside amusing and provocative examples, this paper shows how students can participate in exploratory research with primary sources from the history of mathematics

Response and resilience of Spartina alterniflora to sudden dieback

We measured an array of biophysical and spectral variables to evaluate the response and recovery of Spartina alterniflora to a sudden dieback event in spring and summer 2004 within a low marsh in coastal Virginia, USA. S. alterniflora is a foundation species, whose loss decreases ecosystem services and potentiates ecosystem state change. Long-term records of the potential environmental drivers of dieback such as precipitation and tidal inundation did not evidence any particular anomalies, although Hurricane Isabel in fall 2003 may have been related to dieback. Transects were established across the interface between the dieback area and apparently healthy areas of marsh. Plant condition was classified based on ground cover within transects as dieback, intermediate and healthy. Numerous characteristics of S. alterniflora culms within each condition class were assessed including biomass, morphology and spectral attributes associated with photosynthetic pigments. Plants demonstrated evidence of stress in 2004 and 2005 beyond areas of obvious dieback and resilience at a multi-year scale. Resilience of the plants was evident in recovery of ground cover and biomass largely within 3 y, although a small remnant of dieback persisted for 8 y. Culms surviving within the dieback and areas of intermediate impact had modified morphological traits and spectral response that reflected stress. These morphometric and spectral differences among plant cover condition classes serve as guidelines for monitoring of dieback initiation, effects and subsequent recovery. Although a number of environmental and biotic parameters were assessed relative to causation, the reason for this particular dieback remains largely unknown, however

Architecture and Dynamics of Kepler's Candidate Multiple Transiting Planet Systems

About one-third of the ~1200 transiting planet candidates detected in the first four months of \ik data are members of multiple candidate systems. There are 115 target stars with two candidate transiting planets, 45 with three, 8 with four, and one each with five and six. We characterize the dynamical properties of these candidate multi-planet systems. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to be in resonance, particularly near the 2:1 resonance. We find that virtually all candidate systems are stable, as tested by numerical integrations that assume a nominal mass-radius relationship. Several considerations strongly suggest that the vast majority of these multi-candidate systems are true planetary systems. Using the observed multiplicity frequencies, we find that a single population of planetary systems that matches the higher multiplicities underpredicts the number of singly-transiting systems. We provide constraints on the true multiplicity and mutual inclination distribution of the multi-candidate systems, revealing a population of systems with multiple super-Earth-size and Neptune-size planets with low to moderate mutual inclinations.Comment: 27 pages, 19 figures, 8 tables, emulateapj style. Accepted to ApJ. This version includes several minor changes to the tex

Physiological Correlates of Volunteering

We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level