Complexity, Collective Effects and Modelling of Ecosystems: formation, function and stability

We discuss the relevance of studying ecology within the framework of Complexity Science from a statistical mechanics approach. Ecology is concerned with understanding how systems level properties emerge out of the multitude of interactions amongst large numbers of components, leading to ecosystems that possess the prototypical characteristics of complex systems. We argue that statistical mechanics is at present the best methodology available to obtain a quantitative description of complex systems, and that ecology is in urgent need of ``integrative'' approaches that are quantitative and non-stationary. We describe examples where combining statistical mechanics and ecology has led to improved ecological modelling and, at the same time, broadened the scope of statistical mechanics.Comment: 11 pages and 1 figur

The Plasma Structure of the Cygnus Loop from the Northeastern Rim to the Southwestern Rim

The Cygnus Loop was observed from the northeast to the southwest with XMM-Newton. We divided the observed region into two parts, the north path and the south path, and studied the X-ray spectra along two paths. The spectra can be well fitted either by a one-component non-equilibrium ionization (NEI) model or by a two-component NEI model. The rim regions can be well fitted by a one-component model with relatively low \kTe whose metal abundances are sub-solar (0.1--0.2). The major part of the paths requires a two-component model. Due to projection effects, we concluded that the low kTe (about 0.2 keV) component surrounds the high kTe (about 0.6 keV) component, with the latter having relatively high metal abundances (about 5 times solar). Since the Cygnus Loop is thought to originate in a cavity explosion, the low-kTe component originates from the cavity wall while the high-kTe component originates from the ejecta. The flux of the cavity wall component shows a large variation along our path. We found it to be very thin in the south-west region, suggesting a blowout along our line of sight. The metal distribution inside the ejecta shows non-uniformity, depending on the element. O, Ne and Mg are relatively more abundant in the outer region while Si, S and Fe are concentrated in the inner region, with all metals showing strong asymmetry. This observational evidence implies an asymmetric explosion of the progenitor star. The abundance of the ejecta also indicates the progenitor star to be about 15 M_sun.Comment: 24 pages, 9 figures, Astrophysical Journal in pres

Searching for the 3.5 keV Line in the Stacked Suzaku Observations of Galaxy Clusters

We perform a detailed study of the stacked Suzaku observations of 47 galaxy clusters, spanning a redshift range of 0.01-0.45, to search for the unidentified 3.5 keV line. This sample provides an independent test for the previously detected line. We detect only a 2sigma-significant spectral feature at 3.5 keV in the spectrum of the full sample. When the sample is divided into two subsamples (cool-core and non-cool core clusters), cool-core subsample shows no statistically significant positive residuals at the line energy. A very weak (2sigma-confidence) spectral feature at 3.5 keV is permitted by the data from the non-cool core clusters sample. The upper limit on a neutrino decay mixing angle from the full Suzaku sample is consistent with the previous detections in the stacked XMM-Newton sample of galaxy clusters (which had a higher statistical sensitivity to faint lines), M31, and Galactic Center at a 90% confidence level. However, the constraint from the present sample, which does not include the Perseus cluster, is in tension with previously reported line flux observed in the core of the Perseus cluster with XMM-Newton and Suzaku.Comment: ApJ in press, 9 pages, 3 figure

Counselor Allegiance and Client Expectancy in Neuroscience-Informed Cognitive-Behavior Therapy: A 12-Month Qualitative Follow-Up

This article presents summative findings from a 12-month multiphase mixed-methods pilot study examining counselor and client perceptions of neuroscience-informed cognitive-behavior therapy (nCBT) following clinical application. Results from the first 6 months of the study indicated that the counselor\u27s and client\u27s beliefs about the credibility and effectiveness of nCBT (i.e., expectancy) remained stable from pretreatment to 6 months into treatment. The fourth phase of data collection at the 12-month interval followed an explanatory sequential process whereby the qualitative data were connected to earlier merged quantitative data to better understand initial findings from the first 6 months of the study. Results indicate that counselors\u27 initial comprehension and familiarity with the model, counselor–client trust, counselor delivery and suggestion, and client willingness to practice outside of session were key components to the development of counselor and client belief (expectancy) in the model. Implications for nCBT theory development and application are discussed

Nitrogen availability and forest productivity along a climosequence on Whiteface Mountain, New York

We studied broadleaf and needle-leaf forests along an elevation gradient (600–1200 m) at Whiteface Mountain, New York, to determine relationships among temperature, mineral N availability, and aboveground net primary productivity (ANPP) and controls on the latter two variables. We measured net N mineralization during the growing season, annual litterfall quantity and quality, aboveground woody biomass accumulation, and soil organic matter quality. Inorganic N deposition from cloudwater markedly increases mineral N availability above 1000 m in this region. Consequently, mineral N availability across the climosequence remains relatively constant because N mineralization decreases with increasing elevation. Across this climosequence, air temperature (as growing season degree-days) exerted the most control on ANPP. Nitrogen mineralization was most strongly related to soil growing season degree-days and less so to lignin to N ratios in litter. ANPP was correlated with N mineralization but not with mineral N availability. Combining our data with those from similar studies in other boreal and cool temperate forests shows that N mineralization and ANPP are correlated at local, regional, and interbiome scales. Regarding the persistent question concerning cause and effect in the N mineralization – forest productivity relationship, our data provide evidence that at least in this case, forest productivity is a control on N mineralization

Retrieval of Ocean Surface Windspeed and Rainrate from the Hurricane Imaging Radiometer (HIRAD) Brightness Temperature Observations

The Hurricane Imaging Radiometer (HIRAD) is a new airborne synthetic aperture passive microwave radiometer capable of wide swath imaging of the ocean surface wind speed under heavy precipitation e.g. in tropical cyclones. It uses interferometric signal processing to produce upwelling brightness temperature (Tb) images at its four operating frequencies 4, 5, 6 and 6.6 GHz [1,2]. HIRAD participated in NASA s Genesis and Rapid Intensification Processes (GRIP) mission during 2010 as its first science field campaign. It produced Tb images with ~70 km swath width and 3 km resolution from a ~ 20 km altitude. From this, ocean surface wind speed and column averaged atmospheric liquid water content can be retrieved across the swath. The column averaged liquid water then could be related to an average rain rate. The retrieval algorithm (and the HIRAD instrument itself) is a direct descendant of the nadir-only Stepped Frequency Microwave Radiometer that is used operationally by the NOAA Hurricane Research Division to monitor tropical cyclones [3,4]. However, due to HIRAD s slant viewing geometry (compared to nadir viewing SFMR) a major modification is required in the algorithm. Results based on the modified algorithm from the GRIP campaign will be presented in the paper

The SMC SNR 1E0102.2-7219 as a Calibration Standard for X-ray Astronomy in the 0.3-2.5 keV Bandpass

The flight calibration of the spectral response of CCD instruments below 1.5 keV is difficult in general because of the lack of strong lines in the on-board calibration sources typically available. We have been using 1E 0102.2-7219, the brightest supernova remnant in the Small Magellanic Cloud, to evaluate the response models of the ACIS CCDs on the Chandra X-ray Observatory (CXO), the EPIC CCDs on the XMM-Newton Observatory, the XIS CCDs on the Suzaku Observatory, and the XRT CCD on the Swift Observatory. E0102 has strong lines of O, Ne, and Mg below 1.5 keV and little or no Fe emission to complicate the spectrum. The spectrum of E0102 has been well characterized using high-resolution grating instruments, namely the XMM-Newton RGS and the CXO HETG, through which a consistent spectral model has been developed that can then be used to fit the lower-resolution CCD spectra. We have also used the measured intensities of the lines to investigate the consistency of the effective area models for the various instruments around the bright O (~570 eV and 654 eV) and Ne (~910 eV and 1022 eV) lines. We find that the measured fluxes of the O VII triplet, the O VIII Ly-alpha line, the Ne IX triplet, and the Ne X Ly-alpha line generally agree to within +/-10 % for all instruments, with 28 of our 32 fitted normalizations within +/-10% of the RGS-determined value. The maximum discrepancies, computed as the percentage difference between the lowest and highest normalization for any instrument pair, are 23% for the O VII triplet, 24% for the O VIII Ly-alpha line, 13% for the Ne IX triplet, and 19% for the Ne X Ly-alpha line. If only the CXO and XMM are compared, the maximum discrepancies are 22% for the O VII triplet, 16% for the O VIII Ly-alpha line, 4% for the Ne IX triplet, and 12% for the Ne X Ly-alpha line.Comment: 16 pages, 11 figures, to be published in Proceedings of the SPIE 7011: Space Telescopes and Instrumentation II: Ultraviolet to Gamma Ray 200