NS5-Branes, T-Duality and Worldsheet Instantons

The equivalence of NS5-branes and ALF spaces under T-duality is well known. However, a naive application of T-duality transforms the ALF space into a smeared NS5-brane, de-localized on the dual, transverse, circle. In this paper we re-examine this duality, starting from a two-dimensional N=(4,4) gauged linear sigma model describing Taub-NUT space. After dualizing the circle fiber, we find that the smeared NS5-brane target space metric receives corrections from multi-worldsheet instantons. These instantons are identified as Nielsen-Olesen vortices. We show that their effect is to break the isometry of the target space, localizing the NS5-brane at a point. The contribution from the k-instanton sector is shown to be proportional to the weighted integral of the Euler form over the k-vortex moduli space. The duality also predicts the, previously unknown, asymptotic exponential decay coefficient of the BPS vortex solution.Comment: 26 pages. v2: Fourier modes of multi-vortex fermion zero mode corrected. Reference added. v3: typo correcte

Vortices, Instantons and Branes

The purpose of this paper is to describe a relationship between the moduli space of vortices and the moduli space of instantons. We study charge k vortices in U(N) Yang-Mills-Higgs theories and show that the moduli space is isomorphic to a special Lagrangian submanifold of the moduli space of k instantons in non-commutative U(N) Yang-Mills theories. This submanifold is the fixed point set of a U(1) action on the instanton moduli space which rotates the instantons in a plane. To derive this relationship, we present a D-brane construction in which the dynamics of vortices is described by the Higgs branch of a U(k) gauge theory with 4 supercharges which is a truncation of the familiar ADHM gauge theory. We further describe a moduli space construction for semi-local vortices, lumps in the CP(N) and Grassmannian sigma-models, and vortices on the non-commutative plane. We argue that this relationship between vortices and instantons underlies many of the quantitative similarities shared by quantum field theories in two and four dimensions.Comment: 32 Pages, 4 Figure

The Life and Death of Barn Beetles: Faunas from Manure and Stored Hay inside Farm Buildings in Northern Iceland

This research was funded by the Commonwealth Scholarship Commission and received support from the Research Budget of the Department of Archaeology at the University of Aberdeen. This project was undertaken as part of doctoral studies supervised by Dr Karen Milek, to whom V.F. is especially grateful for her support and advice. Thomas Birch, Sigrún Inga Garðarsdóttir, and Paul Ledger provided invaluable assistance during fieldwork. V.F. would like to dedicate this paper to Tom and Sía, who met during this fieldwork and are getting married this year. Many people from Fornleifastofnun Íslands – Garðar Guðmundsson, Ólöf Þorsteinsdóttir, Þóra Pétursdóttir, Adolf Friðriksson and Uggi Ævarsson – as well as Unnstein Ingason, Ágústa Edwald, and Mark Young, helped with fieldwork logistics. Special thanks are due to all the Icelandic farmers and their families who kindly allowed us to collect insects on their farms and provided help when needed: Hermann Aðalsteinsson, Hermína Fjóla Ingólfsdóttir, Guðmundur Skúlason, Sigrún Á. Franzdóttir, Dúna Magnúsdóttir, Sverrir Steinbergsson, Valgeir Þorvaldsson, Reynir Sveinsson, Jónas Þór Ingólfsson, and Ívar Ólafsson. Eva Panagiotakopulu, Jan Klimaszewski, Ales Smetana, Georges Pelletier, Gabor Pozsgai, and Jenni Stockham helped with some of the beetle identifications. A.J.D. acknowledges the support of National Science Foundation through ARC 1202692. Consultation of the BugsCEP database (Buckland & Buckland, 2006) aided the redaction of this paper. The authors would like to thank David Smith and two anonymous reviewers for insightful comments that helped improve the quality of this paper.Peer reviewedPostprin

Understanding and managing uncertainty and variability for wastewater monitoring beyond the pandemic : lessons learned from the United Kingdom national COVID-19 surveillance programmes

The COVID-19 pandemic has put unprecedented pressure on public health resources around the world. From adversity, opportunities have arisen to measure the state and dynamics of human disease at a scale not seen before. In the United Kingdom, the evidence that wastewater could be used to monitor the SARS-CoV-2 virus prompted the development of National wastewater surveillance programmes. The scale and pace of this work has proven to be unique in monitoring of virus dynamics at a national level, demonstrating the importance of wastewater-based epidemiology (WBE) for public health protection. Beyond COVID-19, it can provide additional value for monitoring and informing on a range of biological and chemical markers of human health. A discussion of measurement uncertainty associated with surveillance of wastewater, focusing on lessons-learned from the UK programmes monitoring COVID-19 is presented, showing that sources of uncertainty impacting measurement quality and interpretation of data for public health decision-making, are varied and complex. While some factors remain poorly understood, we present approaches taken by the UK programmes to manage and mitigate the more tractable sources of uncertainty. This work provides a platform to integrate uncertainty management into WBE activities as part of global One Health initiatives beyond the pandemic

Crescimento de eucalipto sob efeito de desfolhamento artificial

O objetivo deste trabalho foi avaliar os efeitos do desfolhamento total, realizado após o plantio e ao longo do primeiro ano de cultivo, sobre o crescimento de Eucalyptus grandis, desde a implantação até ao corte do povoamento. Foram avaliados cinco tratamentos: sem desfolhamento; um desfolhamento aos 56 dias após o plantio (DAP); dois desfolhamentos, aos 56 e 143 DAP; dois desfolhamentos, aos 56 e 267 DAP; e três desfolhamentos, aos 56, 143 e 278 DAP. Foram mensurados os diâmetros do tronco a 1,3 m e a altura total de 60 árvores por tratamento, em oito avaliações, do 21º ao 92º mês de cultivo. O crescimento médio em cada tratamento foi descrito por modelos de regressão não lineares e comparados por testes de identidade para comparar as tendências entre a testemunha e os demais tratamentos. O desfolhamento causou reduções significativas nas taxas de crescimento em diâmetro e altura das plantas, e diminuição expressiva no faturamento ao final da rotação, mesmo quando realizado uma única vez, no início do plantio. Maiores danos, no entanto, foram verificados após consecutivos desfolhamentos ao longo do primeiro ano de cultivo. A manutenção de áreas que tenham sofrido desfolhamento total na fase inicial de plantio pode tornar-se uma medida economicamente inviável.The objective of this work was to evaluate the effects of total defoliation at planting initial stages, and along the first year of cultivation, on Eucalyptus grandis growth, from planting to plantation cut. Five treatments were tested: without defoliation; one defoliation, at 56th day after planting (DAP); two defoliations, at 56th and 143th DAP; two defoliations, at 56th and 267th DAP; and three defoliations, at 56th, 143th and 278th DAP. Trunk diameter at 1.30-m height and the total height of 60 trees were measured from the 21st to the 92th cultivation months. The average growth of each treatment was described by nonlinear models and compared by identity tests in order to estimate the tendencies between control and the other treatments in each variable. Defoliation significantly reduces diameter of the trunk and height growth rates, and expressively decreases the income at the plantation cut. However, greater losses were verified after consecutive defoliation, along the first cultivation year. Maintaining areas that suffered severe defoliations at initial planting stages can become economically unfeasible

The adoption of agricultural practices for the development of heritable resistance to pests and pathogens in forest crops

Forest management, particularly plantation development, arose largely in response to the erosion of natural forest resources by agriculture. The objectives, skills and methods of farmer and forester have often conflicted yet the rapid rate of improvement possible with annual crops provides lessons and guidance for the development of perennial crops... The farmer is concerned mainly with intensive management of single crops on good sites yielding one product in which uniformity is at a premium and for which the value per unit of volume is high. In contrast the forester commonly acts as an ecologist maintaining annual yields of low value products by extensive management of variable crops on poorer sites with several objectives including protection and amenity as well as production which itself includes a range of properties for a range of uses. The evolution, domestication and some 50 years of intensive breeding of many annual crops have reduced the genetic base, attaining a selection plateau beyond which further gain requires introduction of genes from wild populations in the .natural origins. Forest trees are only two or three generations removed from the wild type and, with the exceptions of some intra-specific, natural population variants and some restricted national breeding populations, tree species have considerable genetic variation available. Nevertheless conservation of genetic resources is essential and, for many species, it is in process. The comparative testing of populations or individual genotypes is more difficult in perennial crops because the extended rotation period and large size of individuals complicate the design, management, assessment and analysis of field trials. The long rotation period and the physical size provide many opportunities in time and space for a range of pests to attack trees, and trees contain large proportions of dead material, such as heartwood, which are subject to types of pest that do not occur in annual crops. Cost-benefit analysis of perennial crops does not encourage the use of artificial pest control measures and the extended commercial rotations and reproductive cycles of forest trees make it essential to develop early testing methods for heritable pest resistance, within the constraints of breeding for several other traits. The bulk of forest plantations are based on introductions of exotic species for which there may be delays in the adaptation of local pests and in the accidental introduction of pests from the trees' natural source. Growth characters, however, may be rapidly changed in new and often sub-optimal environments. Also the adoption of monocultures, even with indigenous species, has provided ideal conditions for establishment and spread of pests. The practice of selective tree breeding and the use of clonal plantations intensify the risk of outbreak. The development of heritable resistance requires knowledge of the biology and life-cycle of the pest (often lacking in tree pests) and it requires at least several years in perennial crops. For trees it is thus of little value in an emergency. Further, prediction of pest problems is less certain with trees than with agricultural crops, since pests of exotic plantations are far from being stabilized. A much higher proportion of important tree pests is likely to be due to facultative, unspecialised organisms. Further, the nature of the problems force the forester to seek resistance mechanisms that are often more complex than those already understood and exploited for annual crops. The possibility of breakdown of resistance and the long generation interval of trees makes vertical resistance unattractive, even though several kinds of major gene resistance may occur in a single host and even with recycling and clonal mixtures. The most appropriate type of resistance is the polygenic horizontal resistance with its conceptual extension to generalised resistance to a wide range of pest species.</p

The adoption of agricultural practices for the development of heritable resistance to pests and pathogens in forest crops

Forest management, particularly plantation development, arose largely in response to the erosion of natural forest resources by agriculture. The objectives, skills and methods of farmer and forester have often conflicted yet the rapid rate of improvement possible with annual crops provides lessons and guidance for the development of perennial crops... The farmer is concerned mainly with intensive management of single crops on good sites yielding one product in which uniformity is at a premium and for which the value per unit of volume is high. In contrast the forester commonly acts as an ecologist maintaining annual yields of low value products by extensive management of variable crops on poorer sites with several objectives including protection and amenity as well as production which itself includes a range of properties for a range of uses. The evolution, domestication and some 50 years of intensive breeding of many annual crops have reduced the genetic base, attaining a selection plateau beyond which further gain requires introduction of genes from wild populations in the .natural origins. Forest trees are only two or three generations removed from the wild type and, with the exceptions of some intra-specific, natural population variants and some restricted national breeding populations, tree species have considerable genetic variation available. Nevertheless conservation of genetic resources is essential and, for many species, it is in process. The comparative testing of populations or individual genotypes is more difficult in perennial crops because the extended rotation period and large size of individuals complicate the design, management, assessment and analysis of field trials. The long rotation period and the physical size provide many opportunities in time and space for a range of pests to attack trees, and trees contain large proportions of dead material, such as heartwood, which are subject to types of pest that do not occur in annual crops. Cost-benefit analysis of perennial crops does not encourage the use of artificial pest control measures and the extended commercial rotations and reproductive cycles of forest trees make it essential to develop early testing methods for heritable pest resistance, within the constraints of breeding for several other traits. The bulk of forest plantations are based on introductions of exotic species for which there may be delays in the adaptation of local pests and in the accidental introduction of pests from the trees' natural source. Growth characters, however, may be rapidly changed in new and often sub-optimal environments. Also the adoption of monocultures, even with indigenous species, has provided ideal conditions for establishment and spread of pests. The practice of selective tree breeding and the use of clonal plantations intensify the risk of outbreak. The development of heritable resistance requires knowledge of the biology and life-cycle of the pest (often lacking in tree pests) and it requires at least several years in perennial crops. For trees it is thus of little value in an emergency. Further, prediction of pest problems is less certain with trees than with agricultural crops, since pests of exotic plantations are far from being stabilized. A much higher proportion of important tree pests is likely to be due to facultative, unspecialised organisms. Further, the nature of the problems force the forester to seek resistance mechanisms that are often more complex than those already understood and exploited for annual crops. The possibility of breakdown of resistance and the long generation interval of trees makes vertical resistance unattractive, even though several kinds of major gene resistance may occur in a single host and even with recycling and clonal mixtures. The most appropriate type of resistance is the polygenic horizontal resistance with its conceptual extension to generalised resistance to a wide range of pest species.</p