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A survey of bat communities in Grand Teton National Park in relation to anthropogenic structures and light
No full textBats (order Chiroptera) are increasingly recognized as critical in diverse ecosystems around the world. However, there have been relatively few studies of bats in Grand Teton National Park (GRTE), such that a great deal remains to be learned about bat communities in the region. We recorded bat echolocation calls with acoustic monitoring device and analyzed recordings with species identification software to characterize bat communities in GRTE. These data, along with data on human-made structures and lightscapes around the park will be used to analyze relationships between bat communities and anthropogenic infrastructure within the park.
Featured photo by Shawna Wolf, taken from the AMK Ranch photo collection
Investigating movement and population genetic structure of Parnassius clodius butterflies in Grand Teton National Park
No full textNumerous species are responding to warming climate by shifting distributions northward and poleward. Butterflies have been instrumental in documenting such climate-induced range shifts. Parnassius clodius is a montane butterfly found throughout the Greater Yellowstone Ecosystem in metapopulations of disconnected dry, gravelly sagebrush meadows. Dispersal among metapopulations will likely strongly determine whether the species can move in response to changing climate. We collected P. clodius in 41 study sites spread throughout the GYE for which we also have occupancy data. Future analysis of genotyping-by-sequencing data for these 209 samples will help describe population structure across the landscape and identify potential landscape features that are barriers to movement for this species.
Featured photo by U. S. Forest Service - Pacific Northwest Region on Flickr. https://flic.kr/p/U7HmLm 
Flowering phenology and bumblebee activity in early summer in Grand Teton National Park
No full textFrom late May through late June we monitored flowering phenology of all plants in four transects in Grand Teton National Park. We identified and collected blooming data on 25 species. In addition, we assessed both bumblebee species composition and foraging activity in the same transects. We captured queens from five different bumblebee species in vane traps. Observations of transects for forager activity yielded little data, and we recommend future studies employ walking transects.
Featured photo by Michael Dillon, taken from the AMK Ranch photo collection
A note on a conjecture for the distance Laplacian matrix
No full textIn this note, the graphs of order n having the largest distance Laplacian eigenvalue of multiplicity n â2 are characterized. In particular, it is shown that if the largest eigenvalue of the distance Laplacian matrix of a connected graph G of order n has multiplicity n â 2, then G = S_n or G = K_(p,p), where n = 2p. This resolves a conjecture proposed by M. Aouchiche and P. Hansen in [M. Aouchiche and P. Hansen. A Laplacian for the distance matrix of a graph. Czechoslovak Mathematical Journal, 64(3):751â761, 2014.]. Moreover, it is proved that if G has P_5 as an induced subgraph then the multiplicity of the largest eigenvalue of the distance Laplacian matrix of G is less than n â 3
An inverse eigenproblem for generalized reflexive matrices with normal -potencies
No full textLet be two normal -potent matrices, i.e., , , . A matrix is referred to as generalized reflexive with two normal -potent matrices and if and only if . The set of all generalized reflexive matrices which rely on the matrices and is denoted by . The left and right inverse eigenproblem of such matrices ask from us to find a matrix containing a given part of left and right eigenvalues and corresponding left and right eigenvectors. In this paper, first necessary and sufficient conditions such that the problem is solvable are obtained. A general representation of the solution is presented. Then an expression of the solution for the optimal Frobenius norm approximation problem is exploited. A stability analysis of the optimal approximate solution, which has scarcely been considered in existing literature, is also developed
Notes on two recent results of Audenaert
No full textIn this article we prove some inequalities for -measurable operators which are related to two recent results of Audenaert
On Energy and Laplacian Energy of Graphs
No full textLet be a simple graph of order with edges. The energy of a graph , denoted by , is defined as the sum of the absolute values of all eigenvalues of . The Laplacian energy of the graph is defined as where are the Laplacian eigenvalues of graph . In this paper, some lower and upper bounds for are presented in terms of number of vertices, number of edges, maximum degree and the first Zagreb index, etc. Moreover, a relation between energy and Laplacian energy of graphs is given
Trees with given maximum degree minimizing the spectral radius
No full textThe spectral radius of a graph is the largest eigenvalue of the adjacency matrix of the graph. Let be the tree which minimizes the spectral radius of all trees of order with exactly vertices of maximum degree . In this paper, is determined for , and for and large enough. It is proven that for sufficiently large , is a caterpillar with (almost) uniformly distributed legs, is a dumbbell, and is a tree consisting of three distinct stars of order connected by three disjoint paths of (almost) equal length from their centers to a common vertex. The unique tree with the largest spectral radius among all such trees is also determined. These extend earlier results of Lov\' asz and Pelik\'an, Simi\' c and To\u si\' c, Wu, Yuan and Xiao, and Xu, Lin and Shu
Optimal Gersgorin-style estimation of the largest singular value. II
No full textIn estimating the largest singular value in the class of matrices equiradial with a given -by- complex matrix , it was proved that it is attained at one of sparse nonnegative matrices (see C.R.~Johnson, J.M.~Pe{\~n}a and T.~Szulc, Optimal Gersgorin-style estimation of the largest singular value; {\em Electronic Journal of Linear Algebra Algebra Appl.}, 25:48--59, 2011). Next, some circumstances were identified under which the set of possible optimizers of the largest singular value can be further narrowed (see C.R.~Johnson, T.~Szulc and D.~Wojtera-Tyrakowska, Optimal Gersgorin-style estimation of the largest singular value, {\it Electronic Journal of Linear Algebra Algebra Appl.}, 25:48--59, 2011). Here the cardinality of the mentioned set for -by- matrices is further reduced. It is shown that the largest singular value, in the class of matrices equiradial with a given -by- complex matrix, is attained at one of sparse nonnegative matrices. Finally, an inequality between the spectral radius of a -by- nonnegative matrix and the spectral radius of a modification of is also proposed
Signal Processing based on Stable radix-2 DCT I-IV Algorithms having Orthogonal Factors
No full textThis paper presents stable, radix-2, completely recursive discrete cosine transform algorithms DCT-I and DCT-III solely based on DCT-I, DCT-II, DCT-III, and DCT-IV having sparse and orthogonal factors. Error bounds for computing the completely recursive DCT-I, DCT-II, DCT-III, and DCT-IV algorithms having sparse and orthogonal factors are addressed. Signal flow graphs are demonstrated based on the completely recursive DCT-I, DCT-II, DCT-III, and DCT-IV algorithms having orthogonal factors. Finally image compression results are presented based on the recursive 2D DCT-II and DCT-IV algorithms for image size 512 by 512 pixels with transfer block sizes 8 by 8, 16 by 16, and 32 by 32 with 93.75% absence of coefficients in each transfer block