Transitions in coral reef accretion rates linked to intrinsic ecological shifts on turbid-zone nearshore reefs

Nearshore coral communities within turbid settings are typically perceived to have limited reef-building capacity. However, several recent studies have reported reef growth over millennial time scales within such environments and have hypothesized that depth-variable community assemblages may act as equally important controls on reef growth as they do in clear-water settings. Here, we explicitly test this idea using a newly compiled chronostratigraphic record (31 cores, 142 radiometric dates) from seven proximal (but discrete) nearshore coral reefs located along the central Great Barrier Reef (Australia). Uniquely, these reefs span distinct stages of geomorphological maturity, as reflected in their elevations below sea level. Integrated age-depth and ecological data sets indicate that contemporary coral assemblage shifts, associated with changing light availability and wave exposure as reefs shallowed, coincided with transitions in accretion rates at equivalent core depths. Reef initiation followed a regional ∼1 m drop in sea level (1200–800 calibrated yr B.P.) which would have lowered the photic floor and exposed new substrate for coral recruitment by winnowing away fine seafloor sediments. We propose that a two-way feedback mechanism exists where past growth history influences current reef morphology and ecology, ultimately driving future reef accumulation and morphological change. These findings provide the first empirical evidence that nearshore reef growth trajectories are intrinsically driven by changes in coral community structure as reefs move toward sea level, a finding of direct significance for predicting the impacts of extrinsically driven ecological change (e.g., coral-algal phase shifts) on reef growth potential within the wider coastal zone on the Great Barrier Reef

ORDINARY LEAST SQUARES REGRESSION OF ORDERED CATEGORICAL DATA: INFERENTIAL IMPLICATIONS FOR PRACTICE

Ordered categorical responses (OCRs) are frequently encountered in many disciplines. Examples of interest in agriculture include quality assessments, such as for soil or food products, and evaluation of lesion severity, such as teat ends status in dairy cattle. OCRs are characterized by multiple categories recorded on a ranked scale that, while apprising relative order, is not informative of absolute magnitude of or proportionality between the categories. A number of statistically sound models for OCRs are available in the statistical literature, such as logistic regression and probit models, but these are commonly underutilized in practice. Instead, the ordinary least squares linear regression (OLSLR) model is often employed despite violation of basic model assumptions. In this study, the inferential implications of OLSLR-based inference on OCRs were investigated using a simulation study that evaluated realized Type I error rate and empirical statistical power. The design of the simulation study was motivated by applications reported in the subject-matter literature. A variety of plausible scenarios were considered for simulation, including various shapes of the frequency distribution and number of categories of the OCR. Using survey data on frequency of antimicrobial use in cattle feedlots, we illustrated the inferential performance of OLSLR on OCRs relative to a probit model

Atoms and Quantum Dots With a Large Number of Electrons: the Ground State Energy

We compute the ground state energy of atoms and quantum dots with a large number N of electrons. Both systems are described by a non-relativistic Hamiltonian of electrons in a d-dimensional space. The electrons interact via the Coulomb potential. In the case of atoms (d=3), the electrons are attracted by the nucleus, via the Coulomb potential. In the case of quantum dots (d=2), the electrons are confined by an external potential, whose shape can be varied. We show that the dominant terms of the ground state energy are those given by a semiclassical Hartree-exchange energy, whose N to infinity limit corresponds to Thomas-Fermi theory. This semiclassical Hartree-exchange theory creates oscillations in the ground state energy as a function of N. These oscillations reflect the dynamics of a classical particle moving in the presence of the Thomas-Fermi potential. The dynamics is regular for atoms and some dots, but in general in the case of dots, the motion contains a chaotic component. We compute the correlation effects. They appear at the order N ln N for atoms, in agreement with available data. For dots, they appear at the order N.Comment: 30 pages, 1 figur

Solitary waves in clouds of Bose-Einstein condensed atoms

We consider the conditions under which solitary waves can exist in elongated clouds of Bose-Einstein condensed atoms. General expressions are derived for the velocity, characteristic size, and spatial profile of solitary waves, and the low- and high-density limits are examined.Comment: 6 pages, revtex, 1 ps figur

The Impact of Corporate Social Responsibility on Mergers and Acquisitions

This study examines the effects of corporate social responsibility (CSR) on merger and acquisitions (M&A). Using data from Kinder, Lyndeberg, and Domini (KLD) Research Analytics and Thomson’s Securities Data Corporation’s (SDC) Platinum Database, we empirically test if CSR scores effect a firm’s propensity to pursue M&A activity. Specifically, I examine how individual elements of CSR ratings (i.e. community relations, corporate governance, diversity, employee relations, environmental practices, and product quality and safety) might directly influence this relationship. The second part of this study examines the problems associated with integration that commonly arise during corporate acquisitions. We attempt to determine what dimensions of CSR increase integration periods by looking at the differences in bidder and target CSR scores

EMG Analysis of Neural Activation Patterns of the Gluteal Muscle Complex

Gluteal amnesia is described as a condition in which the neural recruitment patterns of the gluteal muscle complex are insufficient to activate muscle fibers, causing the hamstring and lower back muscles to take up the physical demand. Symptoms due to insufficient gluteal muscle activation include tight hamstrings post-exercise, anterior pelvic tilt, and knee valgus during squat or lunge performance. This could lead to compensation injuries of the lumbar, knee, and ankle joints. Many physical therapy rehabilitation programs of the lower back and lower extremity incorporate gluteal exercises which could potentially treat this condition and prevent compensation injuries. PURPOSE: To identify and test a person experiencing symptoms of gluteal amnesia to determine gluteal muscle activation before and after a therapy program designed to enhance muscle recruitment and function. METHODS: A 74-year-old male experiencing symptoms of unilateral gluteal amnesia was recruited for this case-study. Electromyographic (EMG) analysis of the gluteal muscle complex was recorded while the subject performed movements typically associated with gluteal muscle complex activation. Both the affected and unaffected side were analyzed while the subject performed movements, as well as submaximal and maximal voluntary isometric contractions (MVIC). After baseline testing, a daily, 3-week progressive resistance rehabilitation program consisting of exercises utilizing the gluteal muscle complex was completed. After completion of the rehabilitation program, EMG analysis of the affected and unaffected sides was performed as during the baseline measures. Integrated EMG signals of gluteal activation were compared between pre- and post-tests. Baseline EMG was considered to be 100% of muscle activation. The post-rehabilitation EMG during MVIC was a percentage of the maximal effort output. MVIC of the submaximal tests were obtained by comparing the quadruped hip extension and single leg glute bridge exercises to the standing gluteal squeeze, and the quadruped hip abduction and clam shell exercises to the side lying hip abduction. RESULTS: Increased gluteal complex activation post-rehabilitation was evident in both the affected and unaffected limbs. Specifically, the largest increases of the left and ride side were seen through the quadruped hip extension (18.7%, 52.4%) and quadruped hip abduction (54.1%, 98.8%) exercises, respectively. The left limb presenting with gluteal amnesia symptoms consistently gave lower output values. CONCLUSION: In this case-study, increased EMG activity in the affected muscles, progressive increases in resistance during daily rehabilitation and anecdotal improvements in movement patterns were observed. Based on the results of this case-study, treatment for conditions such as gluteal amnesia and other disorders of ineffective motor unit recruitment should include targeted rehabilitation exercises designed to isolate the affected musculature

High Dietary Iron and Radiation Exposure Increase Biomarkers of Oxidative Stress in Blood and Liver of Rats

Radiation exposure and increased iron (Fe) status independently cause oxidative damage that can result in protein, lipid, and DNA oxidation. During space flight astronauts are exposed to both increased radiation and increased Fe stores. Increased body Fe results from a decrease in red blood cell mass and the typically high Fe content of the food system. In this study we investigated the combined effects of radiation exposure (0.375 Gy of Cs-137 every other day for 16 days for a total of 3 Gy) and high dietary Fe (650 mg Fe/kg diet compared to 45 mg Fe/kg for controls) in Sprague-Dawley rats (n=8/group). Liver and serum Fe were significantly increased in the high dietary Fe groups. Likewise, radiation treatment increased serum ferritin and Fe concentrations. These data indicate that total body Fe stores increase with both radiation exposure and excess dietary Fe. Hematocrit decreased in the group exposed to radiation, providing a possible mechanism for the shift in Fe indices after radiation exposure. Markers of oxidative stress were also affected by both radiation and high dietary Fe, evidenced by increased liver glutathione peroxidase (GPX) and serum catalase as well as decreased serum GPX. We thus found preliminary indications of synergistic effects of radiation exposure and increased dietary Fe, warranting further study. This study was funded by the NASA Human Research Project

TRITIUM AND DECAY HELIUM EFFECTS ON THE FRACTURE TOUGHNESS PROPERTIES OF STAINLESS STEEL WELDMENTS

J-Integral fracture toughness tests were conducted on tritium-exposed-and-aged Types 304L and 21-6-9 stainless steel weldments in order to measure the combined effects of tritium and its decay product, helium-3 on the fracture toughness properties. Initially, weldments have fracture toughness values about three times higher than base-metal values. Delta-ferrite phase in the weld microstructure improved toughness provided no tritium was present in the microstructure. After a tritium-exposure-and-aging treatment that resulted in {approx}1400 atomic parts per million (appm) dissolved tritium, both weldments and base metals had their fracture toughness values reduced to about the same level. The tritium effect was greater in weldments (67 % reduction vs. 37% reduction) largely because the ductile discontinuous delta-ferrite interfaces were embrittled by tritium and decay helium. Fracture toughness values decreased for both base metals and weldments with increasing decay helium content in the range tested (50-200 appm)

Regenerative capacity in the lamprey spinal cord is not altered after a repeated transection

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 14(1), (2019):e0204193, doi: 10.1371/journal.pone.0204193.The resilience of regeneration in vertebrates is not very well understood. Yet understanding if tissues can regenerate after repeated insults, and identifying limitations, is important for elucidating the underlying mechanisms of tissue plasticity. This is particularly challenging in tissues, such as the nervous system, which possess a large number of terminally differentiated cells and often exhibit limited regeneration in the first place. However, unlike mammals, which exhibit very limited regeneration of spinal cord tissues, many non-mammalian vertebrates, including lampreys, bony fishes, amphibians, and reptiles, regenerate their spinal cords and functionally recover even after a complete spinal cord transection. It is well established that lampreys undergo full functional recovery of swimming behaviors after a single spinal cord transection, which is accompanied by tissue repair at the lesion site, as well as axon and synapse regeneration. Here we begin to explore the resilience of spinal cord regeneration in lampreys after a second spinal transection (re-transection). We report that by all functional and anatomical measures tested, lampreys regenerate after spinal re-transection just as robustly as after single transections. Recovery of swimming, synapse and cytoskeletal distributions, axon regeneration, and neuronal survival were nearly identical after spinal transection or re-transection. Only minor differences in tissue repair at the lesion site were observed in re-transected spinal cords. Thus, regenerative potential in the lamprey spinal cord is largely unaffected by spinal re-transection, indicating a greater persistent regenerative potential than exists in some other highly regenerative models. These findings establish a new path for uncovering pro-regenerative targets that could be deployed in non-regenerative conditions.The authors would like to thank Dr. Cristina Roman-Vendrell and Louie Kerr, Director of the Central Microscopy Facility at the MBL, for technical support. We also thank Dr. Juan Diaz-Quiroz for helpful comments on the manuscript. EG was supported in part by an NSF REU Award (#1659604: Biological Discovery in Woods Hole at the Marine Biological Laboratory)

Black Vulture Conflict and Management in the United States: Damage Trends, Management Overview, and Research Needs

Contrary to rapid declines of many vulture (Accipitridae, Cathartidea) species worldwide, black vulture (Coragyps atratus) populations are increasing and expanding their range in North America. Vultures exhibit complex behaviors and can adapt to any human-dominated landscape or land use. These traits, combined with population growth and range expansion, have contributed to increased human–vulture conflicts. Our goal was to summarize the current status and trends in human–black vulture conflicts (hereafter human–vulture conflicts), review available management strategies, identify knowledge gaps, and provide recommendations to enhance management and understanding of this species and the associated conflicts. We found human–vulture conflicts are increasing in agriculture (livestock), private and public property (both personal and infrastructure-based), and threats to human health and safety. The greatest increases in conflicts were reported in agriculture and private and public property damage. Regarding livestock depredation, good progress has been made toward assessing producer perceptions of the conflicts, including estimates of economic damage and mitigation strategies, but a basic understanding of the underlying mechanism driving the conflict and advancing strategies to mitigate damage is lacking. For damaged property, little information is available regarding economic losses and perceptions of stakeholders who are experiencing the damage, and most of the tools recommended for mitigating this damage have not been rigorously evaluated. Regarding human health and safety, recent research quantifying flight behavior of black vultures has direct implications for reducing aircraft collision risks. However, it is unclear what factors influence roost site selection and the most effective means to leverage the sensory ecology of the species to mitigate risks. We identify additional knowledge gaps and research needs that if addressed could increase managers’ understanding of black vulture ecology and facilitate enhanced management of this species while simultaneously allowing for the species to provide valuable ecosystem services