1,156 research outputs found

    Impact of horses on year around grazing without supplementary feeding on pastoral herbaceous plants

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    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

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    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 NN-expansions with a finite set of digits

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    In this paper we consider a class of continued fraction expansions: the so-called NN-expansions with a finite digit set, where N2N\geq 2 is an integer. These \emph{NN-expansions with a finite digit set} were introduced in [KL,L], and further studied in [dJKN,S]. For NN fixed they are steered by a parameter α(0,N1]\alpha\in (0,\sqrt{N}-1]. In [KL], for N=2N=2 an explicit interval [A,B][A,B] was determined, such that for all α[A,B]\alpha\in [A,B] the entropy h(Tα)h(T_{\alpha}) of the underlying Gauss-map TαT_{\alpha} is equal. In this paper we show that for all NNN\in \mathbb N, N2N\geq 2, 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 TαT_{\alpha}, the TαT_{\alpha}-invariant measure, ergodicity, and we show that for any two α,α\alpha,\alpha' 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

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    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

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    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

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    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

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    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

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    Let GG be a simple graph of order nn with degree sequence (d1,d2,,dn)(d_1,d_2,\cdots,d_n). For an integer p>1p>1, let ep(G)=i=1ndipe_p(G)=\sum_{i=1}^n d^{p}_i and let exp(n,H)ex_p(n,H) be the maximum value of ep(G)e_p(G) among all graphs with nn vertices that do not contain HH as a subgraph (known as HH-free graphs). Caro and Yuster proposed the problem of determining the exact value of ex2(n,C4)ex_2(n,C_4), where C4C_4 is the cycle of length 44. In this paper, we show that if GG is a C4C_4-free graph having n4n\geq 4 vertices and m3(n1)/2m\leq \lfloor 3(n-1)/2\rfloor edges and no isolated vertices, then ep(G)ep(Fn)e_p(G)\leq e_p(F_n), with equality if and only if GG is the friendship graph FnF_n. This yields that for n4n\geq 4, exp(n,C)=ep(Fn)ex_p(n,\mathcal{C}^*)=e_p(F_n) and FnF_n is the unique extremal graph, which is an improved complement of Caro and Yuster's result on exp(n,C)ex_p(n,\mathcal{C}^*), where C\mathcal{C}^* denotes the family of cycles of even lengths. We also determine the maximum value of ep()e_p(\cdot) among all minimally tt-(edge)-connected graphs with small tt or among all kk-degenerate graphs, and characterize the corresponding extremal graphs. A key tool in our approach is majorization
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