Boise State University

About: Boise State University is a education organization based out in Boise, Idaho, United States. It is known for research contribution in the topics: Population & Computer science. The organization has 3698 authors who have published 8664 publications receiving 210163 citations. The organization is also known as: BSU & Boise State.

A Phylogeny of the Tropical Genus Piper Using Its and the Chloroplast Intron psbJ–petA

Abstract: Piper is one of the largest genera of flowering plants. The uniformity of its small flowers and the vast number of species in the genus has hindered the development of a stable infrageneric classification. We sampled 575 accessions corresponding to 332 species of Piper for the ITS region and 181 accessions for the psbJ-petA chloroplast intron to further test previous hypotheses about the major clades within Piper. Phylogenetic analyses were performed for each marker separately and in combination. The ITS region alone resolves eleven major clades within Piper, whereas the psbJ-petA intron fails to recover four of these major groupings and provides no resolution at the base of the phylogeny. The combined analysis provides support for ten monophyletic groups and offers the best hypothesis for relationships in Piper. Our massive ITS dataset allows us to assign confidently a large number of species in this "giant" genus to a major clade. Piper is here divided into ten major clades for which we provide a morphological description. Various clades and subclades are newly identified here: Peltobryon, Schilleria, Isophyllon, P. cinereum/P. sanctum. The clades described here provide a solid framework for future, and more focused, evolutionary studies. New names and combinations proposed herein include Piper bullulatum, P. hooglandii, and P. melchior.

Spatially distributed temperatures at the base of two mountain snowpacks measured with fiber-optic sensors

Abstract: Snowpack base temperatures vary during accumulation and diurnally. Their measurement provides insight into physical, biological and chemical processes occurring at the snow/soil interface. Recent advances in Raman-spectra instruments, which use the scattered light in a standard telecommunications fiber-optic cable to infer absolute temperature along the entire length of the fiber, offer a unique opportunity to obtain basal snow temperatures at resolutions of 1 m, 10 s, and 0.18C. Measurements along a 330 m fiber over 24 hours during late-spring snowmelt at Mammoth Mountain, California, USA, showed basal snow temperatures of 0 � 0.28C using 10 s averages. Where the fiber- optic cable traversed bare ground, surface temperatures approached 408C during midday. The durability of the fiber optic was excellent; no major damage or breaks occurred through the winter of burial. Data from the Dry Creek experimental watershed in Idaho across a small stream valley showed little variability of temperature on the northeast-facing, snow-covered slope, but clearly showed melting patterns and the effects of solar heating on southwest-facing slopes. These proof-of-concept experiments show that the technology enables more detailed spatial and temporal coverage than traditional point measurements of temperature.

Development of the Soil Moisture Index to Quantify Agricultural Drought and Its “User Friendliness” in Severity-Area-Duration Assessment

Abstract: This paper examines the role of soil moisture in quantifying drought through the development of a drought index using observed and modeled soil moisture. In Nebraska, rainfall is received primarily during the crop-growing season and the supply of moisture from the Gulf of Mexico determines if the impending crop year is either normal or anomalous and any deficit of rain leads to a lack of soil moisture storage. Using observed soil moisture from the Automated Weather Data Network (AWDN), the actual available water content for plants is calculated as the difference between observed or modeled soil moisture and wilting point, which is subsequently normalized with the site-specific, soil property–based, idealistic available water for plants that is calculated as the difference between field capacity and wilting point to derive the soil moisture index (SMI). This index is categorized into five classes from no drought to extreme drought to quantitatively assess drought in both space and time. Additional...

Frequency-dependent attenuation analysis of ground-penetrating radar data

Abstract: In the early 1990s, it was established empirically that, in many materials, ground-penetrating radar (GPR) attenuation is approximately linear with frequency over the bandwidth of a typical pulse. Further, a frequency-independent Q* parameter characterizes the slope of the band-limited attenuation versus frequency curve. Here, I derive the band-limited Q* function from a first-order Taylor expansion of the attenuation coefficient. This approach provides a basis for computing Q* from any arbitrary dielectric permittivity model. For Cole-Cole relaxation, I find good correlation between the first-order Q* approximation and Q* computed from linear fits to the attenuation coefficient curve over two-octave bands. The correlation holds over the primary relaxation frequency. For some materials, this relaxation occurs between 10 and 200 MHz , a typical frequency range for many GPR applications. Frequency-dependent losses caused by scattering and by the commonly overlooked problem of frequency-dependent reflection ...