18,400 research outputs found

    Invasive Weeds, Wildfire, and Rancher Decision Making in the Great Basin

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    In this article, a numerical stochastic dynamic programming model (SDP) is developed to characterize the decision problem of a rancher operating on rangelands in northern Nevada that are affected by invasive annual grasses and wildfire. The model incorporates decisions about herd size management of a cow-calf operation and fuels treatment to reduce the size of rangeland wildfires. Currently, high transactions costs to obtain permits to implement land treatments on federally-owned rangelands appear to limit rancher involvement. The results of the model suggest that ranch income motives alone are likely insufficient for private ranchers to adopt preventative land treatments. The current treatment cost ($20 per acre at the minimum) appears to be prohibitively expensive relative to the benefits derived from the treatments under the low-productivity, semi-arid rangeland conditions.stochastic dynamic programming, cow-calf operation, rangeland, ecosystem, Livestock Production/Industries, Resource /Energy Economics and Policy,

    Can the ICC Consider Quesztions on Jus Ad Bellum in a War Crimes Trial?

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    War has forever been considered the utmost necessary evil. Nevertheless, international law has for some time sought to limit the right to wage war (jus ad bellum), as well as the means and methods employed amid war (jus in bello). Although these two branches of law now share humanitarian purposes the prevention of war and its effects -- they have generally been kept separate throughout history. However, confronted with widespread violations of jus in bello, resulting in appalling humanitarian disasters, some have suggested amending their relationship. This was notably sought at the Nuremberg Trials, where prosecutors failed to contend that jus in bello was inapplicable due to the illegal use of force by Germany. More recently, calls are being made to grant the legitimate belligerent more leeway in their application of jus in bello when responding to terrorism and the increasing use of lawfare (abuse of jus in bello to achieve strategic military or political ends). The ICC, as the only permanent criminal court with potentially worldwide jurisdiction, would be best suited to reconsider the relationship between jus ad bellum and jus in bello, potentially discriminating against the illegal belligerent in its assessment of proportionality in attack. In response to these calls for aggressor discrimination, this article will demonstrate that the ICC is prohibited from considering jus ad bellum in a war crimes trial, therefore precluding such discrimination. Suggestions of fighting fire with fire ignore the very principles and rationale of the two branches of law and put innocent civilians at risk. Lowering the humanitarian bar can surely not be the answer to ultimate humanitarian concerns

    Can the ICC Consider Quesztions on Jus Ad Bellum in a War Crimes Trial?

    Get PDF
    War has forever been considered the utmost necessary evil. Nevertheless, international law has for some time sought to limit the right to wage war (jus ad bellum), as well as the means and methods employed amid war (jus in bello). Although these two branches of law now share humanitarian purposes the prevention of war and its effects -- they have generally been kept separate throughout history. However, confronted with widespread violations of jus in bello, resulting in appalling humanitarian disasters, some have suggested amending their relationship. This was notably sought at the Nuremberg Trials, where prosecutors failed to contend that jus in bello was inapplicable due to the illegal use of force by Germany. More recently, calls are being made to grant the legitimate belligerent more leeway in their application of jus in bello when responding to terrorism and the increasing use of lawfare (abuse of jus in bello to achieve strategic military or political ends). The ICC, as the only permanent criminal court with potentially worldwide jurisdiction, would be best suited to reconsider the relationship between jus ad bellum and jus in bello, potentially discriminating against the illegal belligerent in its assessment of proportionality in attack. In response to these calls for aggressor discrimination, this article will demonstrate that the ICC is prohibited from considering jus ad bellum in a war crimes trial, therefore precluding such discrimination. Suggestions of fighting fire with fire ignore the very principles and rationale of the two branches of law and put innocent civilians at risk. Lowering the humanitarian bar can surely not be the answer to ultimate humanitarian concerns

    The Inner Halo of M87: A First Direct View of the Red-Giant Population

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    An unusually deep (V,I) imaging dataset for the Virgo supergiant M87 with the Hubble Space Telescope ACS successfully resolves its brightest red-giant stars, reaching M_I(lim) = -2.5. After assessing the photometric completeness and biasses, we use this material to estimate the metallicity distribution for the inner halo of M87, finding that the distribution is very broad and likely to peak near [m/H] ~ -0.4 and perhaps higher. The shape of the MDF strongly resembles that of the inner halo for the nearby giant E galaxy NGC 5128. As a byproduct of our study, we also obtain a preliminary measurement of the distance to M87 with the TRGB (red-giant branch tip) method; the result is (m-M)_0 = 31.12 +- 0.14 (d = 16.7 +- 0.9 Mpc). Averaging this result with three other recent techniques give a weighted mean d(M87) = (16.4 +- 0.5) Mpc.Comment: In press for Astronomy and Astrophysic

    Developing a partcipatory approach to seed production and varietal selection

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    The performance of UK winter wheat varieties was tested under organic conditions involving farmer participation. Three breadmaking varieties (Hereward, Solstice and Xi19) and their mixture (1:1:1) were grown at 19 UK farms in 2003/04 and 2004/05. The variability of productivity on organic farms was illustrated with more variation among farm sites than among varieties. Seed health was generally high over all sites. Although the trials were successful, more time was needed at project initiation to improve farmer involvement. Some farmers expected more researcher visits, and were reticent about assessing the trials themselves. In contrast, some participants valued the variety performance data on their farms particularly when related to that of other growers. The balance between the goals of the researchers relative to the farmers needs to be defined at project initiation

    Wind tunnel tests of an NACA 23021 airfoil equipped with a slotted extensible and a plain extensible flap

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    An investigation has been made in the NACA 7- by 10-foot wind tunnel of a large chord NACA 23021 airfoil equipped with two arrangements of a completely extended 15 percent chord extensible flap. One of the flaps had a faired juncture, without a gap; the other was provided with a slot between the trailing edge of the airfoil and the nose of the flap. The results showed that the basic airfoil gave the lowest profile-drag coefficients over the low lift range, the airfoil with the plain extensible flap gave the lowest profile-drag coefficients over the moderate lift range, and the airfoil with the slotted extensible flap gave the lowest profile-drag coefficients over the high lift range. The airfoil with the slotted extensible flap had the same maximum lift at a flap deflection of 25 degrees as the airfoil with the plain extensible flap had at a flap deflection of 60 degrees. The results of comparisons of the airfoil pitching-moment coefficients obtained with the two types of flap are dependent upon the basis chosen for comparison. Complete aerodynamic section characteristics are presented for the various flap deflections for both flap arrangements in the completely extended portion

    Structural and Mutational Analysis of Escherichia coli AlkB Provides Insight into Substrate Specificity and DNA Damage Searching

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    Background: In Escherichia coli, cytotoxic DNA methyl lesions on the N1 position of purines and N3 position of pyrimidines are primarily repaired by the 2-oxoglutarate (2-OG) iron(II) dependent dioxygenase, AlkB. AlkB repairs 1-methyladenine (1meA) and 3-methylcytosine (3-meC) lesions, but it also repairs 1-methylguanine (1-meG) and 3-methylthymine (3-meT) at a much less efficient rate. How the AlkB enzyme is able to locate and identify methylated bases in ssDNA has remained an open question. Methodology/Principal Findings: We determined the crystal structures of the E. coli AlkB protein holoenzyme and the AlkBssDNA complex containing a 1-meG lesion. We coupled this to site-directed mutagenesis of amino acids in and around the active site, and tested the effects of these mutations on the ability of the protein to bind both damaged and undamaged DNA, as well as catalyze repair of a methylated substrate. Conclusions/Significance: A comparison of our substrate-bound AlkB-ssDNA complex with our unliganded holoenzyme reveals conformational changes of residues within the active site that are important for binding damaged bases. Sitedirected mutagenesis of these residues reveals novel insight into their roles in DNA damage recognition and repair. Our data support a model that the AlkB protein utilizes at least two distinct conformations in searching and binding methylated bases within DNA: a ‘‘searching’ ’ mode and ‘‘repair’ ’ mode. Moreover, we are able to functionally separate these mode

    An Introduction to the Inverse Quantum Bound State Problem in One Dimension

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    A technique to reconstruct one-dimensional, reflectionless potentials and the associated quantum wave functions starting from a finite number of known energy spectra is discussed. The method is demonstrated using spectra that scale like the lowest energy states of standard problems encountered in the undergraduate curriculum such as: the infinite square well, the simple harmonic oscillator, and the one-dimensional hydrogen atom.Comment: 10 pages, 10 figures, Submitted to Am. J. Phys. August 201

    Bioresorbable Polylactide Interbody Implants in an Ovine Anterior Cervical Discectomy and Fusion Model: Three-Year Results

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    Study Design. In vivo study of anterior discectomy and fusion using a bioresorbable 70:30 poly(l-lactide-co-d,l-lactide) interbody implant in an ovine model. Objective. To evaluate the efficacy of the polylactide implant to function as an interbody fusion device, and to assess the tissue reaction to the material during the resorption process. Summary of Background Data. The use of polylactide as a cervical interbody implant has several potential advantages when compared with traditional materials. Having an elastic modulus very similar to bone minimizes the potential for stress shielding, and as the material resorbs additional loading is transferred to the developing fusion mass. Although preclinical and clinical studies have demonstrated the suitability of polylactide implants for lumbar interbody fusion, detailed information on cervical anterior cervical discectomy and fusion (ACDF) with polylactide devices is desirable. Methods. Single level ACDF was performed in 8 skeletally mature ewes. Bioresorbable 70:30 poly (l-lactide-co-d,l-lactide) interbody implants packed with autograft were used with single-level metallic plates. Radiographs were made every 3 months up to 1 year, and yearly thereafter. The animals were killed at 6 months (3 animals), 12 months (3 animals), and 36 months (2 animals). In addition to the serial plain radiographs, the specimens were evaluated by nondestructive biomechanical testing and undecalcified histologic analysis. Results. The bioresorbable polylactide implants were effective in achieving interbody fusion. The 6-month animals appeared fused radiographically and biomechanically, whereas histologic sections demonstrated partial fusion (in 3 of 3 animals). Radiographic fusion was confirmed histologically and biomechanically at 12 months (3 of 3 animals) and 36 months (2 of 2 animals). A mild chronic inflammatory response to the resorbing polylactide implant was observed at both 6 months and 12 months. At 36 months, the operative levels were solidly fused and the implants were completely resorbed. No adverse tissue response was observed in any animal at any time period. Conclusion. Interbody fusion was achieved using bioresorbable polylactide implants, with no evidence of implant collapse, extrusion, or adverse tissue response to the material. The use of polylactide as a cervical interbody device appears both safe and effective based on these ACDF animal model results
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