Contracting Productivity Growth

In this paper, we analyze the interactions between growth and the contracting environment in the production sector. Allowing incompleteness in contracting implies that viable production relationships for firms and workers, and therefore the profitability of industries, depend on the rates of innovation and growth. The speed at which new innovations arrive in turn depends on the profitability of production, for the usual reasons examined in the endogenous growth literature. We show that these interactions can have important implications which are consistent with observed phenomena in both the micro and macro environment. In particular, we demonstrate how this interaction can lead to a productivity slowdown and a shift in labour market contracts toward more short term arrangements. We show the consistency of an increase in the proportion of the labour force under short term employment, unchanged turnover, increased relative returns of workers in high productivity sectors, and increased income inequality, with a productivity slowdown of finite duration.Endogenous Growth, Incomplete Contracting

The Transversal Relative Equilibria of a Hamiltonian System with Symmetry

We show that, given a certain transversality condition, the set of relative equilibria \mcl E near p_e\in\mcl E of a Hamiltonian system with symmetry is locally Whitney-stratified by the conjugacy classes of the isotropy subgroups (under the product of the coadjoint and adjoint actions) of the momentum-generator pairs $(\mu,\xi)$ of the relative equilibria. The dimension of the stratum of the conjugacy class (K) is $\dim G+2\dim Z(K)-\dim K$, where Z(K) is the center of K, and transverse to this stratum \mcl E is locally diffeomorphic to the commuting pairs of the Lie algebra of $K/Z(K)$. The stratum \mcl E_{(K)} is a symplectic submanifold of P near p_e\in\mcl E if and only if $p_e$ is nondegenerate and K is a maximal torus of G. We also show that there is a dense subset of G-invariant Hamiltonians on P for which all the relative equilibria are transversal. Thus, generically, the types of singularities that can be found in the set of relative equilibria of a Hamiltonian system with symmetry are those types found amongst the singularities at zero of the sets of commuting pairs of certain Lie subalgebras of the symmetry group.Comment: 18 page

Deformation and diagenetic histories around foreland thrust faults

This thesis is concerned with the relationship between deformation and fluid flow along thrust zones. The study was carried out in the Vercors, French Sub-Alpine Chains foreland thrust belt. Study of the thermal alteration of organic matter within the area suggests that prior to west-north-west directed thrusting within the Vercors basin in post middle Miocene times, the rocks now exposed at the surface had not been buried beneath a large thickness of foredeep sediments and remained within the diagenetic realm. Deeper buried levels within the stratigraphy passed into the hydrocarbon generation window prior to thrusting within the Vercors basin. The rocks presently exposed at the surface also remained in the diagenetic realm during and after the thrusting which suggests that thrust sheet loading did not significantly contribute to thermal alteration of organic matter. The structures of the thrust belt may have been possible structural traps for any hydrocarbons which underwent re-migration during the thrusting. The structures have been exhumed by erosion during isostatic uplift. The Rencurel Thrust and overlying Rencurel Thrust Sheet were selected for special study as they are of regional structural importance. The thrust emplaces Urgonian limestones onto Miocene molasse sediments at present erosion levels. The thrust sheet is internally deformed by thrusts and folds. Structural data indicate that the deformation within the thrust sheet and within the Rencurel Thrust Zone occurred during one kinematically linked phase of thrusting. The Rencurel Thrust Zone itself is around 100 metres thick. The higher part of the thrust zone is composed of an array of minor faults developed within the Urgonian. These fault zones are generally less than 10cm wide and are coated in fault gouge. This array of faults is underlain by a gouge zone along the thrust contact between the Urgonian and the Miocene which is several metres thick. The gouge zones were all formed during the action of diffusive mass transfer (DMT) and cataclasis as deformation mechanisms. The wall-rocks to the gouge zones are relatively undeformed by the action of cataclasis. Cataclasis is dilatant and produces fracture porosity which increases the permeability of the fault zones whilst DMT reduces the porosity and permeability of the fault zones due to cement precipitation and pressure dissolution. Cross- cutting relationships between the microstructures indicating the action of cataclasis and DMT, suggest that the porosity and permeability of the fault rocks changed in a complex manner during the incremental deformation. This has important implications for assessing syn-kinematic fluid migration through fault zones. The fault rocks exposed at the surface today are relatively impermeable compared to undeformed wall-rocks away from the fault zone which have permeabilities comparable to those found within hydrocarbon reservoirs. The thrust zone may have been a seal in the sub-surface after the cessation of thrusting but prior to uplift and erosion. Early distributed deformation produced an array of minor faults within the Urgonian. Cataclasis had ceased along these faults before later deformation became localised along the gouge zone which exists along the thrust contact between the Urgonian and the Miocene rocks. Early deformation was accompanied by the migration through fracture porosity of pore waters which were saturated with respect to calcite and had interacted with organic matter which was being thermally altered. This fluid flow system was not connected to fluid flow higher in the stratigraphy which resulted in the precipitation of ferroan calcite within fracture porosity in the Senonian limestones. Late deformation within the thrust zone was accompanied by the migration of hydrocarbons and pore waters saturated with respect to calcite and pyrite. All the pore waters involved in migration through the active thrust zone seem to have migrated up-dip. They migrated from levels in the stratigraphy where organic metamorphism and the maturation of hydrocarbons were occurring to levels in the deformed section which have always remained within the diagenetic realm. Ferroan calcite, pyrite and traces of hydrocarbons have not been found outside the gouge zone along the thrust contact between the Urgonian and Miocene. The fracturing which occurred to open this migration pathway did not re- fracture the inactive minor faults which were impermeable at this time. Fluid migration at this time was confined to beneath the zone of impermeable minor faults in the Urgonian and did not contribute to the diagenesis of the rocks above the thrust zone. Hydrocarbons could not have entered the hanging-wall anticline above the thrust zone from this migration pathway. The fracturing at this time did not produce connected fracture networks pervasively throughout the thrust zone which suggests that the deformation may not have released large amounts of energy in the form of seismic waves

Factors Influencing Shrubland Bird and Native Bee Communities in Forest Openings

Once prevalent on the landscape, early-successional habitats are now increasingly threatened in the northeastern United States. As a result, many species that rely on or require habitats dominated by shrubs, young trees, grasses, and forbs have experienced precipitous population declines, leading many organizations to list shrubland habitats and constituent wildlife as a conservation priority. Even-aged forest management (e.g. clearcutting) has been shown to be an efficient and effective means for creating early-successional habitat for certain taxa such as shrubland birds, but it is unfeasible in many situations in southern New England due to public opinion and increased parcelization. Group selection harvests create shrubland conditions in the form of relatively small forest openings (\u3c 1 ha); however, limited attention has been directed toward understanding the extent to which these methods contribute to conservation of early-successional species. In order to assess the conservation value of small forest openings for wildlife in southern New England, I studied two distinct communities associated with early-successional habitats, shrubland birds and bees (Hymenoptera: Apiformes), in openings created by group selection harvests and patch-cutting. In 2014 and 2015, birds were surveyed in small forest openings in western Massachusetts in an effort to describe relationships between species occurrence and patch area as well as other microhabitat-, patch-, and landscape-level variables. Black-and-white warblers, common yellowthroats, chestnut-sided warblers, eastern towhees, and gray catbirds were likely to be present in openings at least 0.3 ha in size, while indigo buntings and prairie warblers had minimum area requirements of 0.55 and 1.07 ha, respectively. Variables within microhabitat-, patch-, and landscape-levels were important for predicting species occurrence. Most notably, prairie warblers were more likely to occur in openings closer to large patches of habitat such as powerline corridors, even if those openings were small in size. I conclude that, despite their inability to support the entire community of shrubland birds in this region, small forest openings can provide habitat for several species of conservation concern if proper attention is given to promoting suitable microhabitat, patch, and landscape characteristics. Bees were sampled in openings as well as adjacent mature forest in an effort to describe the bee community, identify environmental variables influencing bee abundance and diversity, and examine the extent to which openings created by forest management may support bees, as well as potentially augment bee populations within adjacent unmanaged forest. Bees were significantly more abundant and diverse in forest openings than mature forest, but species composition was indistinguishable between openings and forest. Abundance and diversity displayed no relationship with opening size in either openings or forest, but were generally positively related to the amount of early-successional habitat on the landscape. Vegetation characteristics within openings were important in shaping bee communities in openings, with abundance and diversity decreasing with vegetation height and increasing with floral abundance. Notably, eusocial, soft-wood-nesting, and small bees exhibited the opposite pattern in adjacent forest, increasing with the succession of openings and decreasing with greater floral abundance within openings. These results suggest that the creation of small forest openings may help to promote bees both in openings and adjacent mature forest, but certain guilds may be negatively affected

Creativity and Illness: An anecdotal exploration of a writing practice; Coming Undone: A collection of poems & a thesis as an anecdotal exploration of a writing practice

This thesis combines both creative and critical writing in an exploration of creativity and illness. When I began my candidature, I started writing a novel but found with the diagnosis of chronic illness I could no longer write narrative and was irresistibly drawn to poetry. The collection of poems was written during the period immediately following the diagnosis of, and during my subsequently living with, a chronic autoimmune illness, and is an expression of the lived experience of both being ill and being a writer. The poems have been separated into three chronological parts, each reflective of the emotional changes throughout the disease. That the poems do not focus solely on illness is in part to do with my inability to confront my condition, and in part a reflection that my illness, while influencing my creative practice, is not the same as my creative practice. In the critical portion of the thesis the intersection of creativity and illness is further examined. It explains the themes of my abandoned novel and the subject of grief as seen through Freud’s early work ‘Mourning and Melancholia’, and how that came to be an aspect of my new lived experience as a writer with a chronic illness. It then engages with Jacques Derrida’s theory of différance and discusses how this theory speaks to my switch from prose to poetry. The exegesis explores the nature of writing while ill, and of writing being separate from, as much as informed by, illness. Through an exploration of the work of a number of writers who have recorded their own illness (such as Donald Hall, Siri Hustvedt), or recorded the illness of those close to them (David Rieff, Simone de Beauvoir), the exegetical essay attempts to draw writing into a meaningful interaction with illness. Arthur Frank, Louise DeSalvo, Gregory Orr and others cast writing as a tool for healing; while this may have wider merit, I look at the implications in regards to my own circumstances. Underlying most of the topics explored are some key aspects of the personal versus the universal evident in Terry Eagleton’s How to Read a Poem. The coda looks at how, in a final twist, my illness seems to have been misdiagnosed and so, in many ways, I experienced it metaphorically. This is explored in response to Susan Sontag’s ideas, initially expressed in Illness as Metaphor (2002), regarding illness as a literal experience that becomes complicated by metaphorical language. The coda discusses how my illness seems to have dissipated and what that revision may mean for a discussion of illness and creativity

Wave Functions of the Proton Ground State in the Presence of a Uniform Background Magnetic Field in Lattice QCD

We calculate the probability distributions of quarks in the ground state of the proton, and how they are affected in the presence of a constant background magnetic field. We focus on wave functions in the Landau and Coulomb gauges. We observe the formation of a scalar u-d diquark clustering. The overall distortion of the quark probability distribution under a very large magnetic field, as demanded by the quantisation conditions on the field, is quite small. The effect is to elongate the distributions along the external field axis while localizing the remainder of the distribution.Comment: 15 pages, 18 figure