Forest disturbance and recovery: A general review in the context of spaceborne remote sensing of impacts on aboveground biomass and canopy structure

Abrupt forest disturbances generating gaps \u3e0.001 km2 impact roughly 0.4–0.7 million km2a−1. Fire, windstorms, logging, and shifting cultivation are dominant disturbances; minor contributors are land conversion, flooding, landslides, and avalanches. All can have substantial impacts on canopy biomass and structure. Quantifying disturbance location, extent, severity, and the fate of disturbed biomass will improve carbon budget estimates and lead to better initialization, parameterization, and/or testing of forest carbon cycle models. Spaceborne remote sensing maps large-scale forest disturbance occurrence, location, and extent, particularly with moderate- and fine-scale resolution passive optical/near-infrared (NIR) instruments. High-resolution remote sensing (e.g., ∼1 m passive optical/NIR, or small footprint lidar) can map crown geometry and gaps, but has rarely been systematically applied to study small-scale disturbance and natural mortality gap dynamics over large regions. Reducing uncertainty in disturbance and recovery impacts on global forest carbon balance requires quantification of (1) predisturbance forest biomass; (2) disturbance impact on standing biomass and its fate; and (3) rate of biomass accumulation during recovery. Active remote sensing data (e.g., lidar, radar) are more directly indicative of canopy biomass and many structural properties than passive instrument data; a new generation of instruments designed to generate global coverage/sampling of canopy biomass and structure can improve our ability to quantify the carbon balance of Earth\u27s forests. Generating a high-quality quantitative assessment of disturbance impacts on canopy biomass and structure with spaceborne remote sensing requires comprehensive, well designed, and well coordinated field programs collecting high-quality ground-based data and linkages to dynamical models that can use this information

Using earth observation data to evaluate a land surface model in three Siberian catchments

In this paper, we analyse the ability of the JULES (Joint UK Land Environment Simulator) model to simulate the physical conditions in the terrestrial Arctic using satellite-based earth observation data products. Catchment-average seasonal surface temperatures and snow cover are constructed over the largest river basins of the Eurasian Arctic (the Ob, Lena and Yenisei) and compared with the modelled values. The results indicate that the modelled snow cover decreases too quickly in spring in all studied areas, and that the modelled surface temperature of snow-free areas is too high. There are several causes of uncertainty in both the model outputs and the earth observation products, and care has to be taken to ensure consistent use and sampling of the data. The results indicate that earth observation products provide important information that can assist in the diagnosis of problems in a land-surface model

Low-Cost Flow Visualization for a Supersonic Ejector

Shadowgraph techniques were applied to the cold flow ejector facility at the Propulsion Research Center at the University of Alabama in Huntsville. The setup for the experiments was relatively simple and was accomplished at very little cost. Series of shadowgraph images were taken of both dual nozzle and single nozzle strut based ejectors operating over a range of chamber pressures. The density gradient patterns in the shadowgraphs were compared to pressure data measured along the top and side walls of the mixing duct. The shadowgraph images showed the presence of barrel shocks emanating from the nozzles which at low pressures terminated in Mach disks and at higher pressures extended beyond the barrel shape and reflected off the walls of the duct. Based on pressure data from previous testing, reflected shocks were expected on the walls of the duct. The shadowgraph images confirmed the locations of these reflected shocks on the top wall of the duct. The shadowgraph images also showed the structure change which correlated to a change in pitch of the ejector noise, and corresponded to a change in trend of the duct wall pressure ratio distributions. The images produced from the setup provided insight into the complex flow behavior inside the ejector duct. In addition, the techniques were a valuable tool as an educational device for students

Supernova Remnants in the Fossil Starburst in M82

We report the discovery of ten compact H-alpha-bright sources in the post-starburst region northeast of the center of M82, ``M82 B.'' These objects have H alpha luminosities and sizes consistent with Type II supernova remnants (SNRs). They fall on the same H alpha surface brightness-diameter (Sigma-D) relation defined by SNRs in other nearby star-forming galaxies, with the M82 candidates lying preferentially at the small diameter end. These are the first candidates for optically-visible SNRs in M82 outside the heavily obscured central starburst within ~250 pc from the galactic center. If these sources are SNRs, they set an upper limit to the end of the starburst in region ``B2,'' about 500 pc from the galaxy's core, of ~50 Myr. Region ``B1,'' about 1000 pc from the core, lacks good SNR candidates and is evidently somewhat older. This suggests star formation in the galaxy has propagated inward toward the present-day intense starburst core.Comment: Re-submitted to AJ, referee's comments taken into account, 15 pages LaTeX preprint style, 4 postscript figures; full-resolution figures available from http://www.astro.virginia.edu/~rd7a/snrs/ Changes: minor textual changes and orientation/axes of Fig.

Pion-nucleus elastic scattering on 12C, 40Ca, 90Zr, and 208Pb at 400 and 500 MeV

Pion-nucleus elastic scattering at energies above the Delta(1232) resonance is studied using both pi+ and pi- beams on 12C, 40Ca, 90Zr, and 208Pb. The present data provide an opportunity to study the interaction of pions with nuclei at energies where second-order corrections to impulse approximation calculations should be small. The results are compared with other data sets at similar energies, and with four different first-order impulse approximation calculations. Significant disagreement exists between the calculations and the data from this experiment

Refuge-Deptford mortuary complex

179 p. : ill., maps ; 26 cm.AMNH Library's copies lack t.p.Includes bibliographical references (p. 173-179).Mortuary archaeology on the Georgia coast / David Hurst Thomas and Clark Spencer Larsen -- Archaeological techniques and procedures / David Hurst Thomas and Clark Spencer Larsen -- The Cunningham Mound group / David Hurst Thomas, Clark Spencer Larsen, and Ann Marie Lunsford -- Seaside Mound group / David Hurst Thomas, Clark Spencer Larsen, and Ann Marie Lunsford -- Ceramics / Chester B. DePratter -- Comparisons / David Hurst Thomas -- Implications and some speculations / David Hurst Thomas -- Appendix. Seasonal growth variations in the shells of recent and prehistoric specimens of Mercenaria mercenaria from St. Catherines Island, Georgia / George R. Clark II."Data and implications from nine burial mounds excavated by crews of the American Museum of Natural History on St. Catherines Island, Georgia, are given in this monograph. As a group, these nine sites define a surprisingly homogeneous pattern and these data comprise virtually all that is known regarding the mortuary customs practiced along the Georgia and Florida coast between ca. 1500 B.C. to A.D. 600. The sites are rather unspectacular sand mounds, which exhibit a remarkably consistent stratigraphic patterning. The skeletal materials recovered are poorly preserved, except in the rare case when shell was added to the interment. The radiocarbon evidence, consisting of 29 determinations from the nine mounds, strongly suggests a marked periodicity in the use of these sites. In all cases, the areas seem to have been visited for centuries - in some cases millenia - prior to the actual construction of the mortuary mound. Several graves were placed into this pre-mound surface, and mound-building activities occurred at all sites sometime during the first 600 years A.D. A number of intrusive burials were added shortly thereafter, and then ceremonial activities virtually ceased at all sites. Most cultural materials found inside the mounds were accidental inclusions which resulted from pre-mound sacred (and probably secular) activities. Very few deliberate grave offerings were found. The biocultural evidence suggests that the Refuge-Deptford population enjoyed good health, although they suffered from an extreme rate of dental attrition. Although the data are limited, these sites seem to reflect an egalitarian sociopolitical organization operative during Refuge-Deptford times. The relatively high proportion of bundle burials seems to suggest that the annual round of these peoples exploited both island and mainland resources. We offer a number of cautious speculations regarding the nature of ritual and symbolism during the Refuge and Deptford phases. These suggestions are a variety of hypotheses that require testing with data from both mortuary and habitation sites of this period"--P. 5

Chlorpromazine for schizophrenia: a Cochrane systematic review of 50 years of randomised controlled trials

BACKGROUND: Chlorpromazine (CPZ) remains one of the most common drugs used for people with schizophrenia worldwide, and a benchmark against which other treatments can be evaluated. Quantitative reviews are rare; this one evaluates the effects of chlorpromazine in the treatment of schizophrenia in comparison with placebo. METHODS: We sought all relevant randomised controlled trials (RCT) comparing chlorpromazine to placebo by electronic and reference searching, and by contacting trial authors and the pharmaceutical industry. Data were extracted from selected trials and, where possible, synthesised and random effects relative risk (RR), the number needed to treat (NNT) and their 95% confidence intervals (CI) calculated. RESULTS: Fifty RCTs from 1955–2000 were included with 5276 people randomised to CPZ or placebo. They constitute 2008 person-years spent in trials. Meta-analysis of these trials showed that chlorpromazine promotes a global improvement (n = 1121, 13 RCTs, RR 0.76 CI 0.7 to 0.9, NNT 7 CI 5 to 10), although a considerable placebo response is also seen. People allocated to chlorpromazine tended not to leave trials early in both the short (n = 945, 16 RCTs, RR 0.74 CI 0.5 to 1.1) and medium term (n = 1861, 25 RCTs, RR 0.79 CI 0.6 to 1.1). There were, however, many adverse effects. Chlorpromazine is sedating (n = 1242, 18 RCTs, RR 2.3 CI 1.7 to 3.1, NNH 6 CI 5 to 8), increases a person's chances of experiencing acute movement disorders, Parkinsonism and causes low blood pressure with dizziness and dry mouth. CONCLUSION: It is understandable why the World Health Organization (WHO) have endorsed and included chlorpromazine in their list of essential drugs for use in schizophrenia. Low- and middle-income countries may have more complete evidence upon which to base their practice compared with richer nations using recent innovations

Ursinus College Alumni Journal, November 1966

\u2770 is here • And \u2770 says: Centennial Fund, roll on! • From the President • For Alumni Association leaders, Homecoming Day was some work and plenty of play • An Ursinus specialty: Shaping the future physician • New placement service for alumni • Huck Finn\u27s dilemma is ours • The paradox of urbia • The theatre of the absurd emerges in Latin America • An age of reforming in liberal education: Trends at Ursinus compare with reforms proposed at Columbia University • Sporting scene: Women undefeated in hockey; Soccer; Cross country; Football • Campus clippings: Founders\u27 Day; Sigma Xi Club; Research at Ursinus; Student teachers; The Agency; Mr. Rue remembers; On army duty; Evening school grows; Neighbors come to dinner; Lindback scholar; Parents Day; Job opportunity; \u2767 Ruby underway • Class notebook • Weddings • Births • In memoriamhttps://digitalcommons.ursinus.edu/alumnijournal/1085/thumbnail.jp

Quasi-Periodic Occultation by a Precessing Accretion Disk and Other Variabilities of SMC X-1

We have investigated the variability of the binary X-ray pulsar, SMC X-1, in data from several X-ray observatories. We confirm the ~60-day cyclic variation of the X-ray flux in the long-term monitoring data from the RXTE and CGRO observatories. X-ray light curves and spectra from the ROSAT, Ginga, and ASCA observatories show that the uneclipsed flux varies by as much as a factor of twenty between a high-flux state when 0.71 second pulses are present and a low-flux state when pulses are absent. In contrast, during eclipses when the X-rays consist of radiation scattered from circumsource matter, the fluxes and spectra in the high and low states are approximately the same. These observations prove that the low state of SMC X-1 is not caused by a reduction in the intrinsic luminosity of the source, or a spectral redistribution thereof, but rather by a quasi-periodic blockage of the line of sight, most likely by a precessing tilted accretion disk. In each of two observations in the midst of low states a brief increase in the X-ray flux and reappearance of 0.71 second pulses occurred near orbital phase 0.2. These brief increases result from an opening of the line of sight to the pulsar that may be caused by wobble in the precessing accretion disk. The records of spin up of the neutron star and decay of the binary orbit are extended during 1991-1996 by pulse-timing analysis of ROSAT, ASCA, and RXTE PCA data. The pulse profiles in various energy ranges from 0.1 to >21 keV are well represented as a combination of a pencil beam and a fan beam. Finally, there is a marked difference between the power spectra of random fluctuations in the high-state data from the RXTE PCA below and above 3.4 keV. Deviation from the fitted power law around 0.06 Hz may be QPO.Comment: Accepted to ApJ. 33 pages including 11 figure