Colorado State University

About: Colorado State University is a education organization based out in Fort Collins, Colorado, United States. It is known for research contribution in the topics: Population & Laser. The organization has 31430 authors who have published 69040 publications receiving 2724463 citations. The organization is also known as: CSU & Colorado Agricultural College.

Landscape genetics: where are we now?

Abstract: Landscape genetics has seen rapid growth in number of publications since the term was coined in 2003. An extensive literature search from 1998 to 2008 using keywords associated with landscape genetics yielded 655 articles encompassing a vast array of study organisms, study designs and methodology. These publications were screened to identify 174 studies that explicitly incorporated at least one landscape variable with genetic data. We systematically reviewed this set of papers to assess taxonomic and temporal trends in: (i) geographic regions studied; (ii) types of questions addressed; (iii) molecular markers used; (iv) statistical analyses used; and (v) types and nature of spatial data used. Overall, studies have occurred in geographic regions proximal to developed countries and more commonly in terrestrial vs. aquatic habitats. Questions most often focused on effects of barriers and/or landscape variables on gene flow. The most commonly used molecular markers were microsatellites and amplified fragment length polymorphism (AFLPs), with AFLPs used more frequently in plants than animals. Analysis methods were dominated by Mantel and assignment tests. We also assessed differences among journals to evaluate the uniformity of reporting and publication standards. Few studies presented an explicit study design or explicit descriptions of spatial extent. While some landscape variables such as topographic relief affected most species studied, effects were not universal, and some species appeared unaffected by the landscape. Effects of habitat fragmentation were mixed, with some species altering movement paths and others unaffected. Taken together, although some generalities emerged regarding effects of specific landscape variables, results varied, thereby reinforcing the need for species-specific work. We conclude by: highlighting gaps in knowledge and methodology, providing guidelines to authors and reviewers of landscape genetics studies, and suggesting promising future directions of inquiry.

Surface roughness at the Si(100)-SiO 2 interface

Abstract: We have studied the statistical properties of random surface roughness at the Si-${\mathrm{SiO}}_{2}$ interface using high-resolution transmission electron microscopy (HRTEM). The spectral properties of the HRTEM roughness on normally prepared and intentionally roughened samples appears to be well characterized as a first-order autoregressive or Markovian process which corresponds to an exponential decay in the autocovariance function rather than the usual Gaussian approximation which has been widely used. Such an exponential decay is characterized by tails in the spectrum which are directly attributable to the discrete or steplike nature of the interface roughness which is restricted to occur on crystalline atomic sites. Using a simplified model, we have estimated the effect of projecting the two-dimensional interface roughness through the cross-section thickness to form the one-dimensional boundary studied here. For an isotropic medium, we find that the statistical character of the roughness is preserved during this transformation, but that the rms fluctuation of the roughness is attenuated so that the actual interface is rougher than indicated by the HRTEM technique. After correcting for such averaging, the parameters estimated from the HRTEM are more in agreement with the same parameters used to fit the surface-roughness-limited Hall mobility in metal-oxide-semiconductor field-effect transistor devices.

An unambiguous nomenclature for xyloglucan‐derived oligosaccharides

Abstract: A revised system of abbreviated names is proposed for xyloglucan-derived oligosaccharides. Each (1→4)-linked β-D-glucosyl residue (and the reducing terminal n-glucose moiety) of the backbone is given a one-letter code according to its substituents. The name of the oligosaccharide consists of these code letters listed in sequence from non-reducing to reducing terminus of the backbone

Inorganic Carbon Analysis by Modified Pressure-Calcimeter Method

Abstract: Soil organic C (SOC) analyses using high temperature induction furnace combustion methods have become increasing popular because of advances in instrumentation. Combustion methods, however, also include C from CaCO 3 and CaMg(CO 3 ) 2 found in calcareous soils. Separate analysis of the inorganic C (IC) must be done to correct C data from combustion methods. Our objective was to develop a efficient and precise IC method by modification of the pressure-calcimeter method. We modified the method by using Wheaton serum bottles (20-mL and 100-mL) sealed with butyl rubber stoppers and aluminum tear-off seals as the reaction vessel and a pressure transducer monitored by a digital voltmeter. Our gravimetric IC determination of six soils showed a strong correlation when regressed against IC from the modified pressure-calcimeter method (slope of 0.99, r 2 = 0.998). The method detection limit (MDL) was 0.17 g IC kg -1 for the 20-mL serum bottles and the limit of quantification (LOQ) was 0.30 g IC kg -1 . The 100-mL serum bottle had a MDL of 0.42 with a LOQ of 2.4 g IC kg -1 . When using a 100-mL Wheaton serum bottle as the reaction vessel with a 0.50-g sample size, soils containing up to 120 g IC kg -1 , which represent a 100 % CaCO 3 equivalent, can be analyzed within the V output range of the pressure transducer. Soil organic C determined by subtraction of IC from total C from combustion analysis correlated well with SOC determined by the Walkley-Black.