The Effects of Habitat Alterations on Growth and Vitality of \u3cem\u3eTorreya taxifolia\u3c/em\u3e Arn. in Northern Florida, U.S.A.: a Dendroecological Study

Torreya taxifolia has thrived in the bluffs and moist hammocks along the Apalachicola River in northern Florida and southern Georgia for thousands of years. This species underwent a drastic decline in the mid-1950s. A stem and needle blight, similar to that which destroyed the American chestnut, has resulted in widespread mortality and a virtual halt in sexual reproduction in Torreya throughout its natural range. Because no single invasive, lethal pathogen has been isolated, possible environmental factors that would cause decreased growth and resistance to disease are being examined. Among these factors are changes in local climate and land use regimes. A study of the climate history within the habitat of T. taxifolia may identify the change(s) that have initiated and are currently causing the decline of this species. In addition a climate/growth model for this species should benefit restoration and reintroduction programs. Increment cores and cross sections were taken throughout the range of T. taxifolia. Because T. taxifolia is an endangered species, no samples were taken from live trees. Cross sections were cut from remnant logs of Torreya, and increment cores were extracted from nearby pines. A total of 29 Torreya cross sections and 150 pine increment cores were taken from the collection sites at Woodruff Dam, Torreya State Park, and the Apalachicola Bluffs and Ravines Preserve (ARBP). The samples were prepared and measures using standard dendrochronological techniques. Correlation analyses were conducted using local climate data, including precipitation, temperature, and drought (PHDI) for the purpose of modeling tree-growth response to local climate. Early period and late period growth patterns were compared to determine if a certain mechanism in the local environment weakened these trees making them more susceptible to the stem and needle blight. Historical accounts of change in the habitat and surrounding area were also reviewed to determine if anthropogenic habitat changes, such as the construction of Woodruff Dam near Chattahoochee or local clear-cutting operations, contributed to the increase in mortality of T. taxifolia. A master chronology extending back to 1896 was established using 125 pine cores. Twenty of the T. taxifolia cross sections were successfully dated, extending the chronology back to 1814. I found a significant positive relationship between growth and spring precipitation and an inverse relationship between growth and summer drought severity and summer temperature. The climate-growth response of T. taxifolia mirrored that of the pines, but was not as intense, possibly because of the protected understory habitat. The correlation between tree growth and precipitation suggests that moisture is the strongest determining factor of growth in this area. The inverse relationship with temperature illustrates the effect of higher temperatures on available moisture. A drought and warm period occurred simultaneously during the mid-1950s in combination with heightened clear-cutting practices and the construction of Woodruff Dam. It is my conclusion that habitat deconstruction occurring as early as the turn of the 20th century began weakening the Torreya. The unfavorable climate conditions and rapid degradation of the habitat occurred during the mid-1950s further weakened the Torreya and allowed them to succumb to terminal infection by the blight

Estimation of subsurface porosities and thermal conductivities of polygonal tundra by coupled inversion of electrical resistivity, temperature, and moisture content data

Studies indicate greenhouse gas emissions following permafrost thaw will amplify current rates of atmospheric warming, a process referred to as the permafrost carbon feedback. However, large uncertainties exist regarding the timing and magnitude of the permafrost carbon feedback, in part due to uncertainties associated with subsurface permafrost parameterization and structure. Development of robust parameter estimation methods for permafrost-rich soils is becoming urgent under accelerated warming of the Arctic. Improved parameterization of the subsurface properties in land system models would lead to improved predictions and a reduction of modeling uncertainty. In this work we set the groundwork for future parameter estimation (PE) studies by developing and evaluating a joint PE algorithm that estimates soil porosities and thermal conductivities from time series of soil temperature and moisture measurements and discrete in-time electrical resistivity measurements. The algorithm utilizes the Model-Independent Parameter Estimation and Uncertainty Analysis toolbox and coupled hydrological-thermal-geophysical modeling. We test the PE algorithm against synthetic data, providing a proof of concept for the approach. We use specified subsurface porosities and thermal conductivities and coupled models to set up a synthetic state, perturb the parameters, and then verify that our PE method is able to recover the parameters and synthetic state. To evaluate the accuracy and robustness of the approach we perform multiple tests for a perturbed set of initial starting parameter combinations. In addition, we varied types and quantities of data to better understand the optimal dataset needed to improve the PE method. The results of the PE tests suggest that using multiple types of data improve the overall robustness of the method. Our numerical experiments indicate that special care needs to be taken during the field experiment setup so that (1) the vertical distance between adjacent measurement sensors allows the signal variability in space to be resolved and (2) the longer time interval between resistivity snapshots allows signal variability in time to be resolved

Mie scattering from a sonoluminescing air bubble in water

Applied Optics, Volume 34, No. 15, pp. 2648-2654 (20 May 1995)A single bubble of air in water can emit pulses of blue-white light that have durations of less than 50 ps while it is oscillating in an acoustic standing wave. The emission is called sonoluminescence. A knowledge of the bubble diameter throughout the cycle, and in particular near the time of sonoluminescence emission, can provide important information about the phenomenon. A new Mie scattering technique is developed to determine the size of the bubble through its expansion and collapse during the acoustic cycle. The technique does not rely on an independent means of calibration or on accurate measurements of the scattered intensity.This work was supported in part by the Naval Postgraduate School Research Program and the Office of Naval Research

Influence of hand position on the near-effect in 3D attention

Voluntary reorienting of attention in real depth situations is characterized by an attentional bias to locations near the viewer once attention is deployed to a spatially cued object in depth. Previously this effect (initially referred to as the ‘near-effect’) was attributed to access of a 3D viewer-centred spatial representation for guiding attention in 3D space. The aim of this study was to investigate whether the near-bias could have been associated with the position of the response-hand, always near the viewer in previous studies investigating endogenous attentional shifts in real depth. In Experiment 1, the response-hand was placed at either the near or far target depth in a depth cueing task. Placing the response-hand at the far target depth abolished the near-effect, but failed to bias spatial attention to the far location. Experiment 2 showed that the response-hand effect was not modulated by the presence of an additional passive hand, whereas Experiment 3 confirmed that attentional prioritization of the passive hand was not masked by the influence of the responding hand on spatial attention in Experiment 2. The pattern of results is most consistent with the idea that response preparation can modulate spatial attention within a 3D viewer-centred spatial representation

Evaluating Evidence for the Role of Sleep in Fibromyalgia: A Test of the Sleep and Pain Diathesis Model

The Sleep and Pain Diathesis (SAPD) Model predicts that sleep quality is related to Fibromylagia (FM) outcomes such as disability and depression and that these relationships are mediated by both pain and impaired emotional dysregulation. The purpose of this paper is to provide a preliminary test of this model using cross-sectional data. 35 adult women, who had been living with FM for an average of 13 years, completed a battery of questionnaires that included reports of pain, sleep, affect, and disability. Consistent with this model, FM patients who reported more disrupted sleep also reported higher levels of psychological disability (i.e., BDI depression symptoms) and physical disability. Moreover, the trajectory of the relationship between sleep and pain appears to be mediated by cognitive processes such as increased pain helplessness and, thus, the relationship between sleep and disability appears to be mediated via pain. These data are consistent with the SAPD model, and lend support for the need to include sleep related factors as a critical contributor to our understanding of FM

Identification of direct residue contacts in protein-protein interaction by message passing

Understanding the molecular determinants of specificity in protein-protein interaction is an outstanding challenge of postgenome biology. The availability of large protein databases generated from sequences of hundreds of bacterial genomes enables various statistical approaches to this problem. In this context covariance-based methods have been used to identify correlation between amino acid positions in interacting proteins. However, these methods have an important shortcoming, in that they cannot distinguish between directly and indirectly correlated residues. We developed a method that combines covariance analysis with global inference analysis, adopted from use in statistical physics. Applied to a set of >2,500 representatives of the bacterial two-component signal transduction system, the combination of covariance with global inference successfully and robustly identified residue pairs that are proximal in space without resorting to ad hoc tuning parameters, both for heterointeractions between sensor kinase (SK) and response regulator (RR) proteins and for homointeractions between RR proteins. The spectacular success of this approach illustrates the effectiveness of the global inference approach in identifying direct interaction based on sequence information alone. We expect this method to be applicable soon to interaction surfaces between proteins present in only 1 copy per genome as the number of sequenced genomes continues to expand. Use of this method could significantly increase the potential targets for therapeutic intervention, shed light on the mechanism of protein-protein interaction, and establish the foundation for the accurate prediction of interacting protein partners.Comment: Supplementary information available on http://www.pnas.org/content/106/1/67.abstrac

Neural Processing of Emotional Musical and Nonmusical Stimuli in Depression

Background Anterior cingulate cortex (ACC) and striatum are part of the emotional neural circuitry implicated in major depressive disorder (MDD). Music is often used for emotion regulation, and pleasurable music listening activates the dopaminergic system in the brain, including the ACC. The present study uses functional MRI (fMRI) and an emotional nonmusical and musical stimuli paradigm to examine how neural processing of emotionally provocative auditory stimuli is altered within the ACC and striatum in depression. Method Nineteen MDD and 20 never-depressed (ND) control participants listened to standardized positive and negative emotional musical and nonmusical stimuli during fMRI scanning and gave subjective ratings of valence and arousal following scanning. Results ND participants exhibited greater activation to positive versus negative stimuli in ventral ACC. When compared with ND participants, MDD participants showed a different pattern of activation in ACC. In the rostral part of the ACC, ND participants showed greater activation for positive information, while MDD participants showed greater activation to negative information. In dorsal ACC, the pattern of activation distinguished between the types of stimuli, with ND participants showing greater activation to music compared to nonmusical stimuli, while MDD participants showed greater activation to nonmusical stimuli, with the greatest response to negative nonmusical stimuli. No group differences were found in striatum. Conclusions These results suggest that people with depression may process emotional auditory stimuli differently based on both the type of stimulation and the emotional content of that stimulation. This raises the possibility that music may be useful in retraining ACC function, potentially leading to more effective and targeted treatments

1987: Abilene Christian College Bible Lectures - Full Text

THE MIND OF CHRIST Being the Abilene Christian University Annual Bible Lectures 1987 Published by A.C.U. Press 1634 Campus Court Abilene, Texas 7960

Primate modularity and evolution: first anatomical network analysis of primate head and neck musculoskeletal system

Network theory is increasingly being used to study morphological modularity and integration. Anatomical network analysis (AnNA) is a framework for quantitatively characterizing the topological organization of anatomical structures and providing an operational way to compare structural integration and modularity. Here we apply AnNA for the first time to study the macroevolution of the musculoskeletal system of the head and neck in primates and their closest living relatives, paying special attention to the evolution of structures associated with facial and vocal communication. We show that well-defined left and right facial modules are plesiomorphic for primates, while anthropoids consistently have asymmetrical facial modules that include structures of both sides, a change likely related to the ability to display more complex, asymmetrical facial expressions. However, no clear trends in network organization were found regarding the evolution of structures related to speech. Remarkably, the increase in the number of head and neck muscles – and thus of musculoskeletal structures – in human evolution led to a decrease in network density and complexity in humans