1,156 research outputs found
Impact of horses on year around grazing without supplementary feeding on pastoral herbaceous plants
European grasslands and the biodiversity therein are lost as a result of changes in land use, which
has led to the necessity for the development of effective restoration strategies. This study
investigates the impact of reintroducing a Swedish national breed of horses (Gotland Russ) on
herbaceous plant diversity in abandoned agricultural landscapes in southeast Sweden. Twelve horses
were introduced into three 10-13 hectare enclosures in a three-year (2014-2016) rewilding
experiment. Plant species richness, evenness, and diversity were investigated in both grazed and ungrazed
areas. The results indicated that horse grazing significantly increased herbaceous plant
species diversity and richness, with higher Shannon and Simpson diversity indices in grazed areas.
In addition, the abundance of white clover (Trifolium repens), a signal species beneficial to
pollinators, increased significantly in grazed areas. These findings emphasise the necessity of
integrating large herbivore grazing into ecological restoration practices. In light of the recently
enacted EU restoration law, which aims to restore 20% of Europe's degraded ecosystems by 2030,
this research provides critical insights into scalable restoration methods. The implementation of
rewilding strategies that include large herbivores could enhance the resilience and biodiversity of
European grasslands and forests, thereby aligning with the EU's restoration goals
Underrepresented Students’ Perspectives on Higher Education Equity in the University of California’s Elimination of the Standardized Testing Requirement: A Critical Policy Analysis
In July 2022, the University of California (UC) permanently eliminated the standardized tests requirement for its freshman admissions in order to alleviate the severed socioeconomic gap and college access barriers that were heightened by the COVID-19 pandemic. This critical policy analysis research explored the immediate effects of UC’s policy reform on higher education equity. All 14 participants were underrepresented minority (URM) students who applied to at least one UC campus for fall 2022’s freshman admissions and were enrolled in four-year universities at the time of this study. From demographic surveys, focus groups, and in-depth interviews, I applied critical race theory (CRT) tenets and internalized oppression theory to explore, interpret, and provide counter-narratives of URM students’ college planning and application experiences after the policy reform. From analyzing these students’ perceptions of the elimination of the standardized tests requirement and UC’s admissions equity, I identified the following four findings: 1. Insidiousness of Higher Education Racism: The Role of Standardized Testing in Admissions 2. Enduring Internalized Oppression: The Lingering Effects of the Legitimization of Standardized test requirement 3. Intersectionality of Race, Income, First-Generation College Students’ Status, and Pandemic Impacts 4. Increased Trust in the Higher Education Admissions System After application and identification, I critically discussed the research findings and provided implications for future policies, practices, and research directions for higher education admissions equity based on the four findings. In conclusion and alignment with the CRT tenet of interest convergence, UC’s policy has increased opportunities for all students and has benefited both White and underrepresented minority URM students in terms of their acceptance into highly selective, four-year universities
Matching of orbits of certain -expansions with a finite set of digits
In this paper we consider a class of continued fraction expansions: the
so-called -expansions with a finite digit set, where is an
integer. These \emph{-expansions with a finite digit set} were introduced in
[KL,L], and further studied in [dJKN,S]. For fixed they are steered by a
parameter . In [KL], for an explicit interval
was determined, such that for all the entropy
of the underlying Gauss-map is equal. In this
paper we show that for all , , such plateaux exist. In
order to show that the entropy is constant on such plateaux, we obtain the
underlying planar natural extension of the maps , the
-invariant measure, ergodicity, and we show that for any two
from the same plateau, the natural extensions are metrically
isomorphic, and the isomorphism is given explicitly. The plateaux are found by
a property called matching
Stability of port-Hamiltonian systems with mixed time delays subject to input saturation
In this paper, we investigate the stability of port-Hamiltonian systems with mixed time-varying delays as well as input saturation. Three types of time delays, including state delay, input delay, and output delay, are all assumed to be bounded. By introducing the output feedback control law and utilizing serval Lyapunov–Krasovskii functionals, we present three delay-dependent stability criteria in terms of the linear matrix inequality. Meanwhile, we use Wirtinger’s inequality, constraint conditions, and Lyapunov–Krasovskii functionals of triple and quadruple integral form to obtain less conservative results. Some numerical examples demonstrate and support our results
GSAE: an autoencoder with embedded gene-set nodes for genomics functional characterization
Bioinformatics tools have been developed to interpret gene expression data at
the gene set level, and these gene set based analyses improve the biologists'
capability to discover functional relevance of their experiment design. While
elucidating gene set individually, inter gene sets association is rarely taken
into consideration. Deep learning, an emerging machine learning technique in
computational biology, can be used to generate an unbiased combination of gene
set, and to determine the biological relevance and analysis consistency of
these combining gene sets by leveraging large genomic data sets. In this study,
we proposed a gene superset autoencoder (GSAE), a multi-layer autoencoder model
with the incorporation of a priori defined gene sets that retain the crucial
biological features in the latent layer. We introduced the concept of the gene
superset, an unbiased combination of gene sets with weights trained by the
autoencoder, where each node in the latent layer is a superset. Trained with
genomic data from TCGA and evaluated with their accompanying clinical
parameters, we showed gene supersets' ability of discriminating tumor subtypes
and their prognostic capability. We further demonstrated the biological
relevance of the top component gene sets in the significant supersets. Using
autoencoder model and gene superset at its latent layer, we demonstrated that
gene supersets retain sufficient biological information with respect to tumor
subtypes and clinical prognostic significance. Superset also provides high
reproducibility on survival analysis and accurate prediction for cancer
subtypes.Comment: Presented in the International Conference on Intelligent Biology and
Medicine (ICIBM 2018) at Los Angeles, CA, USA and published in BMC Systems
Biology 2018, 12(Suppl 8):14
MicroRNA-like RNAs from the same miRNA precursors play a role in cassava chilling responses
Abstract MicroRNAs (miRNAs) are known to play important roles in various cellular processes and stress responses. MiRNAs can be identified by analyzing reads from high-throughput deep sequencing. The reads realigned to miRNA precursors besides canonical miRNAs were initially considered as sequencing noise and ignored from further analysis. Here we reported a small-RNA species of phased and half-phased miRNA-like RNAs different from canonical miRNAs from cassava miRNA precursors detected under four distinct chilling conditions. They can form abundant multiple small RNAs arranged along precursors in a tandem and phased or half-phased fashion. Some of these miRNA-like RNAs were experimentally confirmed by re-amplification and re-sequencing, and have a similar qRT-PCR detection ratio as their cognate canonical miRNAs. The target genes of those phased and half-phased miRNA-like RNAs function in process of cell growth metabolism and play roles in protein kinase. Half-phased miR171d.3 was confirmed to have cleavage activities on its target gene P-glycoprotein 11, a broad substrate efflux pump across cellular membranes, which is thought to provide protection for tropical cassava during sharp temperature decease. Our results showed that the RNAs from miRNA precursors are miRNA-like small RNAs that are viable negative gene regulators and may have potential functions in cassava chilling responses
Supervised Sparsity Preserving Projections for Face Recognition
Recently feature extraction methods have commonly been used as a principled approach to understand the intrinsic structure hidden in high-dimensional data. In this paper, a novel supervised learning method, called Supervised Sparsity Preserving Projections (SSPP), is proposed. SSPP attempts to preserve the sparse representation structure of the data when identifying an efficient discriminant subspace. First, SSPP creates a concatenated dictionary by class-wise PCA decompositions and learns the sparse representation structure of each sample under the constructed dictionary using the least squares method. Second, by maximizing the ratio of non-local scatter to local scatter, a Laplacian discriminant function is defined to characterize the separability of the samples in the different sub-manifolds. Then, to achieve improved recognition results, SSPP integrates the learned sparse representation structure as a regular term into the Laplacian discriminant function. Finally, the proposed method is converted into a generalized eigenvalue problem. The extensive and promising experimental results on several popular face databases validate the feasibility and effectiveness of the proposed approach
Extremal results on degree powers in some classes of graphs
Let be a simple graph of order with degree sequence
. For an integer , let
and let be the maximum value of among all graphs with
vertices that do not contain as a subgraph (known as -free graphs). Caro
and Yuster proposed the problem of determining the exact value of
, where is the cycle of length . In this paper, we show
that if is a -free graph having vertices and edges and no isolated vertices, then ,
with equality if and only if is the friendship graph . This yields
that for , and is the unique
extremal graph, which is an improved complement of Caro and Yuster's result on
, where denotes the family of cycles of
even lengths. We also determine the maximum value of among all
minimally -(edge)-connected graphs with small or among all
-degenerate graphs, and characterize the corresponding extremal graphs. A
key tool in our approach is majorization
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