Localization and traces in open-closed topological Landau-Ginzburg models

We reconsider the issue of localization in open-closed B-twisted Landau-Ginzburg models with arbitrary Calabi-Yau target. Through careful analsysis of zero-mode reduction, we show that the closed model allows for a one-parameter family of localization pictures, which generalize the standard residue representation. The parameter $\lambda$ which indexes these pictures measures the area of worldsheets with $S^2$ topology, with the residue representation obtained in the limit of small area. In the boundary sector, we find a double family of such pictures, depending on parameters $\lambda$ and $\mu$ which measure the area and boundary length of worldsheets with disk topology. We show that setting $\mu=0$ and varying $\lambda$ interpolates between the localization picture of the B-model with a noncompact target space and a certain residue representation proposed recently. This gives a complete derivation of the boundary residue formula, starting from the explicit construction of the boundary coupling. We also show that the various localization pictures are related by a semigroup of homotopy equivalences.Comment: 36 page

On the boundary coupling of topological Landau-Ginzburg models

I propose a general form for the boundary coupling of B-type topological Landau-Ginzburg models. In particular, I show that the relevant background in the open string sector is a (generally non-Abelian) superconnection of type (0,1) living in a complex superbundle defined on the target space, which I allow to be a non-compact Calabi-Yau manifold. This extends and clarifies previous proposals. Generalizing an argument due to Witten, I show that BRST invariance of the partition function on the worldsheet amounts to the condition that the (0,<= 2) part of the superconnection's curvature equals a constant endomorphism plus the Landau-Ginzburg potential times the identity section of the underlying superbundle. This provides the target space equations of motion for the open topological model.Comment: 21 page

Responses to stimulation of coronary and carotid baroreceptors and the coronary chemoreflex at different ventricular distending pressures in anaesthetised dogs

Stimulation of left ventricular mechanoreceptors was believed not only to exert important effects on the circulation, but also to influence the responses to baroreceptor reflexes. However, most previous work is flawed due to inadequate localisation of stimuli to specific reflexogenic areas. In this study, we applied a discrete stimulus to left ventricular mechanoreceptors to examine other reflexes known to effect the circulation. Dogs were anaesthetised, artificially ventilated and a cardiopulmonary bypass established. The pressure distending the left ventricle was controlled through an apical cannula with the aortic valve obstructed by a balloon. Changes in ventricular systolic and end-diastolic pressure had only a small effect on vascular resistance, assessed as perfusion pressure in the systemic circulation (flow constant). Responses to changes in carotid or coronary pressure or to stimulation of chemosensitive afferents by injecting veratridine into the coronary circulation were always much larger. Responses to stimulation of these reflexes were little affected by the level of stimulus to the ventricular receptors. These experiments confirm that responses to stimulation of ventricular mechanoreceptors are very small and show that they remain small at different levels of input to other baroreceptive regions. There was no evidence of interaction between ventricular mechanoreceptor reflexes and carotid or coronary baroreceptors or ventricular chemosensitive reflexes

Luminescence dating of ditch fills from the Headland Archaeology Ltd. excavation of Newry Ring Fort, Northern Ireland

This study supports a new investigation into the construction, occupation and utilisation history of a Mediaeval ring fort near Newry, southwest Northern Ireland (section 2). Optically stimulated luminescence (OSL) profiling and age determinations have been made for two sequences of sediments accumulated in the ring ditch surrounding the fort, and potential has been assessed for TL dating of a Souterrain-Ware sherd from a pit feature within the site complex (section 3). The archaeological significance of the age determinations has been reviewed in the light of the luminescence results and the samples’ depositional contexts, to constrain the deposition/formation dates of the sampled sediments (section 6).&lt;p&gt;&lt;/p&gt; A total of 31 profiling (sections 5.1, 5.2) and 12 age (section 5.5) determinations were made. Profiling measurements were made using simplified equivalent dose determination procedures on polymineral coarse and hydrofluoric etched sand-sized mineral grains (sections 4.2.2). Dose rate determinations were made using thick source beta counting, high-resolution gamma spectrometry, field gamma spectrometry, measured water contents and calculated cosmic dose rates (sections 4.2.1 and 5.3). Equivalent dose determinations were made (sections 4.2.2, 5.4) using the OSL signals from sand sized grains of quartz separated from each sample.&lt;p&gt;&lt;/p&gt; The luminescence behaviour of the Newry Ringfort samples was generally very good. Profiling indicated variable levels of residual luminescence signal through the sections (sections 5.1, 5.2), but OSL on the etched fraction was found to be least affected, and measurements on fully prepared quartz for dating appeared even less so (sections 6.1, 6.2). Dose rates ranged from 2.6 to 3.9 mGy/a, De values from the dating samples ranged from 0.7 to 5.0 Gy. Estimates of sediment accumulation date ranged from 410AD to 1750AD (section 5.5). Uncertainties on the age estimates were commonly around 3%, but young samples with scattered equivalent dose distributions had estimated age uncertainties of up to 11%.&lt;p&gt;&lt;/p&gt; The external dose rate to the sherd was estimated to be 1.33 mGy/a ± 0.12 (sections 6.3, 7). Precision was limited by uncertainties in average water content during burial rather than heterogeneity in the gamma radiation field: providing the range of sediment radioactivity at a site can be assessed, and the average burial water contents of sherds excavated from it can be well constrained, then it is likely that sherds from around a site could be dated with sufficient precision to establish a broad chronology for Souterrain-Ware.&lt;p&gt;&lt;/p&gt; The earliest sediments in the ditch of the ringfort indicated that its construction predates the end of the 6th Century AD (sections 6.4, 7). These and other OSL age estimates indicated continued occupation until the mid 11th Century, or phases of occupation in the 7th, 9th and 11th Centuries. Results from the base of a colluvial soil sealing these layers indicate that the site was set to cultivation at or around the time of the Norman invasion of Ireland (1169AD), rather than in the post Mediaeval period. Abandonment of the ringfort must have occurred at the time of the invasion or in the century before it. Samples from throughout the colluvial soil also indicated that it continued to accumulate until at least the 18th Century, and probably into the 20th Century

Stratigraphy of Lower Cretaceous Trinity Deposits of Central Texas

UT Librarie

Gauge-fixing, semiclassical approximation and potentials for graded Chern-Simons theories

We perform the Batalin-Vilkovisky analysis of gauge-fixing for graded Chern-Simons theories. Upon constructing an appropriate gauge-fixing fermion, we implement a Landau-type constraint, finding a simple form of the gauge-fixed action. This allows us to extract the associated Feynman rules taking into account the role of ghosts and antighosts. Our gauge-fixing procedure allows for zero-modes, hence is not limited to the acyclic case. We also discuss the semiclassical approximation and the effective potential for massless modes, thereby justifying some of our previous constructions in the Batalin-Vilkovisky approach.Comment: 46 pages, 4 figure

Organizational Culture and Network Embeddedness

A question that has been neglected in network research is where differences in network embeddedness come from.The network literature reveals that there are three key characteristics of embedded relationships: trust, open communication, and joint problem solving.On the basis of the sparse empirical studies of factors leading to network embeddedness, we identify organizational culture as a potentially important organizational-level factor.Building on empirical organizational culture studies we select ten dimensions of organizational culture that for theoretical and/or empirical reasons can be linked to network embeddedness, and formulate propositions concerning their effects.corporate culture;networks

Organizational Culture and Relationship Skills

While both the strategic management and the network literature recognize the importance of inter-firm relationships for explaining competitive advantage, the question why firms differ in their ability to benefit from these relationships is rarely addressed.This paper aims to begin to fill this gap in the literature. We argue that organizational culture is an important factor influencing the relationship skills of a firm, defined as a firm s ability to manage its ties with other firms, whether these are customers, suppliers, or service providers. We assume relationship skills to be especially relevant for the formation and maintenance of close and durable transaction ties.We test our model on a dataset of 127 Dutch inter-firm relations and find general support.Specifically, we find that firms with organizational cultures characterized by an orientation towards stability and predictability, a positive orientation towards innovation, and not characterized by a strong focus on immediate results, score high on relationship skills.Relationship skills, in turn, are found to have a positive influence on the outcomes of inter-firm relationships in terms of learning, achieving innovations and gaining new contacts, but not in terms of immediate (financial) results.corporate culture;interorganizational relations;networks;strategic management;stability;alliance;Netherlands

EFFECT OF TRADITIONAL PROCESSING METHODS ON THE NUTRITIONAL AND ANTINUTRITIONAL COMPOSITION OF TURMERIC (Curcuma longa)

Turmeric (Curcuma longa)in the past was consumed in small quantity as a spice, but in recent times, it's beingconsumed in large quantities because of the several reported health benefits associated with it. However, thepresence of some antinutrients may pose health challenge and therefore prevent harnessing of the full nutritionalbenefits of turmeric. The research therefore, was conducted to determine the best method amongst the currenttraditional methods of processing turmeric practiced, that will reduce the antinutients and at the same time retainmuch of the macro and micronutrients. The commonly practiced processing methods evaluated were boiling plussundrying, shade drying and sundrying alone. The elements evaluated include: antinutrients(oxalate, alkaloids,flavonoids, saponins, tannins and phenols), macronutrients (protein, fat, fibre and carbohydrate) and themicronutrients which include: vitamin C, vitamin A and mineral elements (calcium, magnesium, potassium andsodium). The results obtained showed that all processing methods significantly (p˂0.5) reduced the antinutrientcontents, but, boiling plus sundrying was most efficient, followed by shade drying. However, shade dryingretained more of the micronutrients while sun drying alone showed the least efficiency in both antinutrientreduction and nutrient retention. Therefore, from the results obtained, boiling and shade drying is recommendedas more efficient processing methods that will reduce the antinutrients and retain much of the macro andmicronutrients

The relationship between population growth and poverty in Africa: a view from the south

The apparent intractability of the problem posed by widespread poverty in Africa has made it an international issue. Thus discussions and debates on the subject have been dominated by bilateral aid agencies, international Non-Government Organizations (NGOs) and development banks. The mainstream view from these debates and discussions is that rapid population growth in Africa has put pressure on the environment, leading to environmental degradation which translates into shortfall in food production and atrophied development. This view is as a result of ritualistic adherence to narrow ideological considerations and predetermined stereotypes about Africa. From a political economy perspective, this paper re-appraises the relationship between population growth and poverty in Africa. Quantitative and qualitative evidence are drawn from the relationship between the ever-increasing complexities of the social dynamics that shape livelihood on the African continent and the wider global context of poverty in Africa. This paper locates the source of poverty in Africa outside the increase in population which should actually be viewed as on advantage to the economy of Africa where machines have not replaced manual labour. Key words; Population growth, Poverty, Political economy, Degradatio