The Utility of Transient Sensitivity for Wildlife Management and Conservation: Bison as a Case Study

Developing effective management strategies is essential to conservation biology. Population models and sensitivity analyses on model parameters have provided a means to quantitatively compare different management strategies, allowing managers to objectively assess the resulting impacts. Inference from traditional sensitivity analyses (i.e., eigenvalue sensitivity methods) is only valid for a population at its stable age distribution, while more recent methods have relaxed this assumption and instead focused on transient population dynamics. However, very few case studies, especially in long-lived vertebrates where transient dynamics are potentially most relevant, have applied these transient sensitivity methods and compared them to eigenvalue sensitivity methods. We use bison (Bison bison) at Badlands National Park as a case study to demonstrate the benefits of transient methods in a practical management scenario involving culling strategies. Using an age and stage-structured population model that incorporates culling decisions, we find that culling strategies over short time-scales (e.g., 1–5 years) are driven largely by the standing population distribution. However, over longer time-scales (e.g., 25 years), culling strategies are governed by reproductive output. In addition, after 25 years, the strategies predicted by transient methods qualitatively coincide with those predicted by traditional eigenvalue sensitivity. Thus, transient sensitivity analyses provide managers with information over multiple time-scales in contrast to the long time-scales associated with eigenvalue sensitivity analyses. This flexibility is ideal for adaptive management schemes and allows managers to balance short-term goals with long-term viability

Experimental determination of line energies, line widths and relative transition probabilities of the Gadolinium L x ray emission spectrum

In this work the most intense x ray lines of the L emission spectrum of gadolinium with respect to line energies, natural line widths, and relative transition probabilities were investigated using monochromatized synchrotron radiation. The measurements were realized in the PTB laboratory at BESSY II by means of an in house built von Hamos spectrometer based on up to two full cylinder HAPG mosaic crystals. The von Hamos spectrometer is calibrated by means of elastically scattered photons from the employed synchrotron radiation beamline leading to a well defined energy scale and an experimentally determined spectrometer response. A selective excitation of the gadolinium L subshells was carried out to ensure a robust deconvolution of neighboring emission lines of different L subshells. The experimental results are discussed in the context of existing data from common databases and published values since significant deviations, especially for the L and L emission lines, are observed. We further substantiate and discuss two satellite lines at the low energy side of the L and L emission lines arising from the N4,5 subshel

Complementary methodologies for thin film characterization in one tool a novel instrument for 450 mm wafers

The scaling down of critical dimensions for the manufacturing of nanoelectronics requires the continuous introduction of new materials. The results of the analysis of thin high-k films made from Al2O3 as reference samples were used at multiple laboratories to show the power and strength of complementary metrology, e.g. using various techniques, such as synchrotron radiation X-ray spectrometry, 'table top' grazing incidence X-ray spectrometry and X-ray reflectometry, and spectroscopic ellipsometry. The layer thicknesses and material parameters validated by several analytical techniques demonstrate the successes of the use of complementary metrology. The requirement for validation, assurance, and support using differing analytical methods is driving the integration of multiple methods into one tool. This paper proposes an integrated metrology approach for reliable characterization of structure and composition. For the analysis of surfaces and materials, light sources in different spectral ranges, e. g. X-rays or infrared light, are used for diffraction, scattering, or excitation of fluorescence. The use of appropriate detectors in the scattering or fluorescence geometry is indispensable. Highly precise metrology requires accurate positioning of the sample with respect to the sources and the detectors. The handling unit for samples and automation are the main contributors to the cost of the semiconductor metrology equipment. For this reason, the approach of integrating multiple analytical techniques has advantages with respect to cost aspects and handling steps. A design study of the 450 mm analytical platform was performed. This design study integrates seven complementary analytical methods into one metrology chamber. Five methods rely on X-ray characterization methods, such as Total Reflection X-Ray Fluorescence Analysis (TXRF), Grazing Incidence X-Ray Fluorescence Analysis (GIXRF/XRF), X-Ray Reflectometry (XRR), X-Ray Diffractometry (XRD), and Grazing Incidence Small Angle X-Ray Scattering (GISAXS). Furthermore, the two methods of spectroscopic ellipsometry and vacuum UV reflectometry using the spectral range of ultra-violet to infrared were supplemented. A novel 5-axis positioning system was designed and patented, enabling the integration of all analytical methods into one chamber under vacuum or atmospheric conditions

Survival and Breeding Transitions for a Reintroduced Bison Population: A Multistate Approach

The iconic plains bison (Bison bison) have been reintroduced to many places in their former range, but there are few scientific data evaluating the success of these reintroductions or guiding the continued management of these populations. Relying on mark–recapture data, we used a multistate model to estimate bison survival and breeding transition probabilities while controlling for the recapture process. We tested hypotheses in these demographic parameters associated with age, sex, reproductive state, and environmental variables. We also estimated biological process variation in survival and breeding transition probabilities by factoring out sampling variation. The recapture rate of females and calves was high (0.78 ± 0.15 [SE]) and much lower for males (0.41 ± 0.23), especially older males (0.17 ± 0.15). We found that overall bison survival was high (\u3e0.8) and that males (0.80 ± 0.13) survived at lower rates than females (0.94 ± 0.04), but as females aged survival declined (0.89 ± 0.05 for F ≥15 yr old). Lactating and non-lactating females survived at similar rates. We found that females can conceive early (approx. 1.5 yr of age) and had a high probability (approx. 0.8) of breeding in consecutive years, until age 13.5 years, when females that were non-lactating tended to stay in that state. Our results suggest senescence in reproduction and survival for females. We found little support for the effect of climatic covariates on demographic rates, perhaps because the park\u27s current population management goals were predicated from drought-year conditions. This reintroduction has been successful, but continued culling actions will need to be employed and an adaptive management approach is warranted. Our demographic approach can be applied to other heavily managed large-ungulate systems with few or no natural predators