Cancellation of UV Divergences in the N=4 SUSY Nonlinear Sigma Model in Three Dimensions

We study the UV properties of the three-dimensional ${\cal N}=4$ SUSY nonlinear sigma model whose target space is $T^*(CP^{N-1})$ (the cotangent bundle of $CP^{N-1}$) to higher orders in the 1/N expansion. We calculate the $\beta$-function to next-to-leading order and verify that it has no quantum corrections at leading and next-to-leading orders.Comment: 10 pages, 2 figures. references adde

Unrelated Helpers in a Primitively Eusocial Wasp: Is Helping Tailored Towards Direct Fitness?

The paper wasp Polistes dominulus is unique among the social insects in that nearly one-third of co-foundresses are completely unrelated to the dominant individual whose offspring they help to rear and yet reproductive skew is high. These unrelated subordinates stand to gain direct fitness through nest inheritance, raising the question of whether their behaviour is adaptively tailored towards maximizing inheritance prospects. Unusually, in this species, a wealth of theory and empirical data allows us to predict how unrelated subordinates should behave. Based on these predictions, here we compare helping in subordinates that are unrelated or related to the dominant wasp across an extensive range of field-based behavioural contexts. We find no differences in foraging effort, defense behaviour, aggression or inheritance rank between unrelated helpers and their related counterparts. Our study provides no evidence, across a number of behavioural scenarios, that the behaviour of unrelated subordinates is adaptively modified to promote direct fitness interests

Starting Ones Own Business What Motivates Entrepreneurs?

The purpose of this study was to determine the factors that motivate and challenge people when starting up their own small business. This paper includes the challenges that entrepreneurs encounter, advantages and disadvantages of owning ones own business, as well as highlighting the factors that are important to succeed in owning ones own business. The study was quantitative in nature and made use of an online survey questionnaire to collect data from entrepreneurs and potential entrepreneurs in KwaZulu Natal, South Africa. The results indicated that the most motivational factors include the desire to pursue a business idea and that they want to be their own boss. The results further highlighted that the main challenges for small business owners are financial in nature as well as support from the government

Pregnancy is detected via odour in a wild cooperative breeder

Among mammals, scent has long been known to encode oestrus, however in many species detecting pregnancy may also be important in terms of both competition and mate-choice. Here we show, through odour presentation experiments, that pregnancy is discernible via scent by both sexes in the cooperatively breeding banded mongoose. Males spent more time investigating and were more likely to scent mark the odours of non-pregnant females, compared to pregnant females. Females showed increased levels of scent marking when odours were of the same reproductive state as themselves. These results present the first direct demonstration that pregnancy is detectable via scent in wild cooperative breeders. Detecting pregnancy may be particularly important in cooperative breeders as, in addition to the competition between males for receptive mates, there is also intense competition between females for access to alloparental care. Consequently, dominant females benefit from targeting reproductive suppression towards subordinates that represent direct threats, such as pregnant females

Policing of reproduction by hidden threats in a cooperative mammal

The evolution of cooperation in animal and human societies is associated with mechanisms to suppress individual selfishness. In insect societies, queens and workers enforce cooperation by “policing” selfish reproduction by workers. Insect policing typically takes the form of damage limitation after individuals have carried out selfish acts (such as laying eggs). In contrast, human policing is based on the use of threats that deter individuals from acting selfishly in the first place, minimizing the need for damage limitation. Policing by threat could in principle be used to enforce reproductive suppression in animal societies, but testing this idea requires an experimental approach to simulate reproductive transgression and provoke out-of-equilibrium behavior. We carried out an experiment of this kind on a wild population of cooperatively breeding banded mongooses (Mungos mungo) in Uganda. In this species, each group contains multiple female breeders that give birth to a communal litter, usually on the same day. In a 7-y experiment we used contraceptive injections to manipulate the distribution of maternity within groups, triggering hidden threats of infanticide. Our data suggest that older, socially dominant females use the threat of infanticide to deter selfish reproduction by younger females, but that females can escape the threat of infanticide by synchronizing birth to the same day as older females. Our study shows that reproduction in animal societies can be profoundly influenced by threats that remain hidden until they are triggered experimentally. Coercion may thus extend well beyond the systems in which acts of infanticide are common

Kin discrimination via odour in the cooperatively breeding banded mongoose

Kin discrimination is often beneficial for group-living animals as it aids in inbreeding avoidance and providing nepotistic help. In mammals, the use of olfactory cues in kin discrimination is widespread and may occur through learning the scents of individuals that are likely to be relatives, or by assessing genetic relatedness directly through assessing odour similarity (phenotype matching). We use scent presentations to investigate these possibilities in a wild population of the banded mongoose Mungos mungo, a cooperative breeder in which inbreeding risk is high and females breed communally, disrupting behavioural cues to kinship. We find that adults show heightened behavioural responses to unfamiliar (extra-group) scents than to familiar (within-group) scents. Interestingly, we found that responses to familiar odours, but not unfamiliar odours, varied with relatedness. This suggests that banded mongooses are either able to use an effective behavioural rule to identify likely relatives from within their group, or that phenotype matching is used in the context of within-group kin recognition but not extra-group kin recognition. In other cooperative breeders, familiarity is used within the group and phenotype matching may be used to identify unfamiliar kin. However, for the banded mongoose this pattern may be reversed, most likely due to their unusual breeding system which disrupts within-group behavioural cues to kinship

Tomographic image reconstruction from continuous projections

An important design aspect in tomographic image reconstruction is the choice between a step-and-shoot protocol versus continuous X-ray tube movement for image acquisition. A step-and-shoot protocol implies a perfectly still tube during X-ray exposure, and hence involves moving the tube to its next position only in between exposures. In a continuous movement protocol, the tube is in a constant motion. The angular integration of the rays inherently produces blurred projections. Conventional reconstruction from such projections leads to blurred reconstructed images, and therefore the projection angles are kept small. Important advantages of a continuous scanning protocol are shorter acquisition times and less demands on modality construction from a mechanical point of view. In this work, the continuous protocol is extended with continuous projections, in which the X-ray source is continuously emitting X-rays over larger angles. The focal spot motion can no longer be ignored and is modeled in the reconstruction. The reconstruction quality is compared with the equivalent step-and-shoot counterpart showing improved results for region of interest tomography

Diffuse continuum transfer in H II regions

We compare the accuracy of various methods for determining the transfer of the diffuse Lyman continuum in HII regions, by comparing them with a high-resolution discrete-ordinate integration. We use these results to suggest how, in multidimensional dynamical simulations, the diffuse field may be treated with acceptable accuracy without requiring detailed transport solutions. The angular distribution of the diffuse field derived from the numerical integration provides insight into the likely effects of the diffuse field for various material distributions.Comment: 12 pages, 7 figures, to be published in MNRA

Social polarisation at the local level: a four-town comparative study on the challenges of politicising inequality in Britain

This paper examines how intensifying inequality in the UK plays out at a local level, in order to bring out the varied ways polarisation takes place ‘on the ground’. It brings a community analysis buttressed by quantitative framing to the study of economic, spatial and relational polarisation in four towns in the United Kingdom. We distinguish differing dynamics of ‘elite-based’ polarisation (in Oxford and Tunbridge Wells) and ‘poverty-based’ polarisation (in Margate and Oldham). Yet there are also common features. Across the towns, marginalised communities express a sense of local belonging. But tensions between social groups also remain strong and all towns are marked by a weak or ‘squeezed middle’. We argue that the weakness of intermediary institutions, including but not limited to the ‘missing middle’, and capable of bridging gaps between various social groups, provides a major insight into both the obstacles to, and potential solutions for, re-politicizing inequality today