Soil organic carbon and root distribution in a temperate arable agroforestry system

Aim To determine, for arable land in a temperate area, the effect of tree establishment and intercropping treatments, on the distribution of roots and soil organic carbon to a depth of 1.5 m. Methods A poplar (Populus sp.) silvoarable agroforestry experiment including arable controls was established on arable land in lowland England in 1992. The trees were intercropped with an arable rotation or bare fallow for the first 11 years, thereafter grass was allowed to establish. Coarse and fine root distributions (to depths of up to 1.5 m and up to 5 m from the trees) were measured in 1996, 2003, and 2011. The amount and type of soil carbon to 1.5 m depth was also measured in 2011. Results The trees, initially surrounded by arable crops rather than fallow, had a deeper coarse root distribution with less lateral expansion. In 2011, the combined length of tree and understorey vegetation roots was greater in the agroforestry treatments than the control, at depths below 0.9 m. Between 0 and 1.5 m depth, the fine root carbon in the agroforestry treatment (2.56 t ha-1) was 79% greater than that in the control (1.43 t ha-1). Although the soil organic carbon in the top 0.6 m under the trees (161 t C ha-1) was greater than in the control (142 t C ha-1), a tendency for smaller soil carbon levels beneath the trees at lower depths, meant that there was no overall tree effect when a 1.5 m soil depth was considered. From a limited sample, there was no tree effect on the proportion of recalcitrant soil organic carbon. Conclusions The observed decline in soil carbon beneath the trees at soil depths greater than 60 cm, if observed elsewhere, has important implication for assessments of the role of afforestation and agroforestry in sequestering carbon

Link-Prediction Enhanced Consensus Clustering for Complex Networks

Many real networks that are inferred or collected from data are incomplete due to missing edges. Missing edges can be inherent to the dataset (Facebook friend links will never be complete) or the result of sampling (one may only have access to a portion of the data). The consequence is that downstream analyses that consume the network will often yield less accurate results than if the edges were complete. Community detection algorithms, in particular, often suffer when critical intra-community edges are missing. We propose a novel consensus clustering algorithm to enhance community detection on incomplete networks. Our framework utilizes existing community detection algorithms that process networks imputed by our link prediction based algorithm. The framework then merges their multiple outputs into a final consensus output. On average our method boosts performance of existing algorithms by 7% on artificial data and 17% on ego networks collected from Facebook

Network Analysis on Incomplete Structures.

Over the past decade, networks have become an increasingly popular abstraction for problems in the physical, life, social and information sciences. Network analysis can be used to extract insights into an underlying system from the structure of its network representation. One of the challenges of applying network analysis is the fact that networks do not always have an observed and complete structure. This dissertation focuses on the problem of imputation and/or inference in the presence of incomplete network structures. I propose four novel systems, each of which, contain a module that involves the inference or imputation of an incomplete network that is necessary to complete the end task. I first propose EdgeBoost, a meta-algorithm and framework that repeatedly applies a non-deterministic link predictor to improve the efficacy of community detection algorithms on networks with missing edges. On average EdgeBoost improves performance of existing algorithms by 7% on artificial data and 17% on ego networks collected from Facebook. The second system, Butterworth, identifies a social network user's topic(s) of interests and automatically generates a set of social feed ``rankers'' that enable the user to see topic specific sub-feeds. Butterworth uses link prediction to infer the missing semantics between members of a user's social network in order to detect topical clusters embedded in the network structure. For automatically generated topic lists, Butterworth achieves an average top-10 precision of 78%, as compared to a time-ordered baseline of 45%. Next, I propose Dobby, a system for constructing a knowledge graph of user-defined keyword tags. Leveraging a sparse set of labeled edges, Dobby trains a supervised learning algorithm to infer the hypernym relationships between keyword tags. Dobby was evaluated by constructing a knowledge graph of LinkedIn's skills dataset, achieving an average precision of 85% on a set of human labeled hypernym edges between skills. Lastly, I propose Lobbyback, a system that automatically identifies clusters of documents that exhibit text reuse and generates ``prototypes'' that represent a canonical version of text shared between the documents. Lobbyback infers a network structure in a corpus of documents and uses community detection in order to extract the document clusters.PhDComputer Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133443/1/mattburg_1.pd

The Vastness of Small Spaces: Self-Portraits of the Artist as a Child Enclosed

A tent of bed sheets, a furniture fort, a corner of the closet surrounded by chosen objects--the child finds or fashions these spaces and within them daydreaming begins. What do small spaces signify for the child, and why do scenes of enclosure emerge in autobiographical self-portraits of the artist? Sigmund Freud\u27s theory that the literary vocation can be traced to childhood experiences is at the heart of this project, especially his observation that the child at play behaves like a writer, in that he creates a world of his own, or rather, re-arranges the things of this world in a new way. Gaston Bachelard\u27s exploration of space and poetic reverie is also foundational, and I situate Freud\u27s child at play within Bachelard\u27s spatial topography in order to examine the ways in which enclosures facilitate the discovery and development of the child\u27s creative capacity. The paradoxical relation between smallness and vastness is a central theme in this dissertation; as the child imagines a world of her own within the small space, spatial constraints dissolve or vanish. My first chapters consider representations of childhood space in the work of two British memoirists at midcentury, Virginia Woolf and Denton Welch, and in the third chapter, I analyze lyric self-portraits by three American poets of the postwar period: Frank O\u27Hara, Anne Sexton, and Robert Duncan. Others have suggested that childhood enclosures are symbolic of womb or cave, but these interpretations fail to capture the complexity of meanings at play within these scenes. I argue that this recurring figure is less about a lost union with the maternal body or some atavistic memory of the beginning of history; rather, for the author tracing the origins of her creative vocation to childhood, the small space is where the artist is born

Legitimate concern: the assault on the concept of rape

In this piece, I will explore the efforts of the Right to delegitimize the legal gains made by women in the fight against rape. I will begin with a brief context of rape law in America, and then explain exactly what precedent the judicial system in Michigan set for a woman’s ability to achieve justice legally in terms of rape. Then, I will show the response of the New Right (through multi-faceted means) to fight against the credibility of women who both legally and politically. Finally, I will show the manifestation of this response in the present-day rise of Men\u27s Rights Activists, amorphous and ambiguous movements which seek to dismantle rape laws online

A Study of the Clinical and Hemodynamic Derangements Associated With Isolated Ventricular Septal Defect

Abstract Not Provided

The St. Lawrence Islanders Of Northwest Cape: Patterns Of Resource Utilization

Thesis (Ph.D.) University of Alaska Fairbanks, 197

Field dynamics and tunneling in a flux landscape

We investigate field dynamics and tunneling between metastable minima in a landscape of Type IIB flux compactifications, utilizing monodromies of the complex structure moduli space to continuously connect flux vacua. After describing the generic features of a flux-induced potential for the complex structure and Type IIB axio-dilaton, we specialize to the Mirror Quintic Calabi--Yau to obtain an example landscape. Studying the cosmological dynamics of the complex structure moduli, we find that the potential generically does not support slow-roll inflation and that in general the landscape separates neatly into basins of attraction of the various minima. We then discuss tunneling, with the inclusion of gravitational effects, in many-dimensional field spaces. A set of constraints on the form of the Euclidean paths through field space are presented, and then applied to construct approximate instantons mediating the transition between de Sitter vacua in the flux landscape. We find that these instantons are generically thick-wall and that the tunneling rate is suppressed in the large-volume limit. We also consider examples where supersymmetry is not broken by fluxes, in which case near-BPS thin-wall bubbles can be constructed. We calculate the bubble wall tension, finding that it scales like a D- or NS-brane bubble, and comment on the implications of this correspondence. Finally, we present a brief discussion of eternal inflation in the flux-landscape.Comment: 23 PRD-style pages with 11 embedded figures. Added refs, corrected typos, and clarified Sec. V. Replaced to match published versio

Gene of the issue: ANO6 and Scott Syndrome.

Scott Syndrome is a very rare inhibited bleeding disorder characterised by an isolated deficit in procoagulant activity in platelets and other blood cells, caused by a lack of phosphatidylserine (PS) exposure following activation.[1,2] It results from mutations in ANO6, which encodes the phospholipid scramblase protein, TMEM16F.[3]British Heart Foundation FS/15/62/3203