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War, in human and animal societies, can be extremely costly but can also offer significant benefits to the victorious group. We might expect groups to go into battle when the potential benefits of victory ( V ) outweigh the costs of escalated conflict ( C ); however, V and C are unlikely to be distributed evenly in heterogeneous groups. For example, some leaders who make the decision to go to war may monopolize the benefits at little cost to themselves (‘exploitative’ leaders). By contrast, other leaders may willingly pay increased costs, above and beyond their share of V (‘heroic’ leaders). We investigated conflict initiation and conflict participation in an ecological model where single-leader–multiple-follower groups came into conflict over natural resources. We found that small group size, low migration rate and frequent interaction between groups increased intergroup competition and the evolution of ‘exploitative’ leadership, while converse patterns favoured increased intragroup competition and the emergence of ‘heroic’ leaders. We also found evidence of an alternative leader/follower ‘shared effort’ outcome. Parameters that favoured high contributing ‘heroic’ leaders, and low contributing followers, facilitated transitions to more peaceful outcomes. We outline and discuss the key testable predictions of our model for empiricists studying intergroup conflict in humans and animals. This article is part of the theme issue ‘Intergroup conflict across taxa’.

Small, Micro and Medium Entreprises (SMMEs) in South African townships, as in many countries worldwide, has a high failure rate. Effective use of marketing and other initiatives made available by the South African government, can help to decrease the number of failures. In order to assist SMMEs effectively, it is necessary to know how they approach marketing, what their training needs are and if they are aware of the initiatives available to assist them with various business functions. A survey was conducted in this regard with small business owners across South African townships. It can be concluded from the research that marketing plays a vital role in the growth and sustainability of a SMME. SMMEs that experienced a decline in growth in the previous year required more marketing training. The growth decline ratio is 1:1.08. It is furthermore clear from the marketing approach in relation to turnover ratios, that SMMEs that grew in turnover over the past three years are almost twice as active in performing marketing functions as the SMMEs that experienced a decline in turnover in the past three years. The need for marketing training was also pointed out as the most poignant training required by SMMEs. It can thus be deduced that the role and importance thereof cannot be overstated since the need expressed warrants the importance. The majority of respondents also indicated that they are not aware of any governmental programmes to assist SMMEs with their marketing.

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.

An individual's ecological environment affects their mortality risk, which in turn has fundamental consequences for life-history evolution. In many species, social relationships are likely to be an important component of an individual's environment, and therefore their mortality risk. Here, we examine the relationship between social position and mortality risk in resident killer whales (Orcinus orca) using over three decades of social and demographic data. We find that the social position of male, but not female, killer whales in their social unit predicts their mortality risk. More socially integrated males have a significantly lower risk of mortality than socially peripheral males, particularly in years of low prey abundance, suggesting that social position mediates access to resources. Male killer whales are larger and require more resources than females, increasing their vulnerability to starvation in years of low salmon abundance. More socially integrated males are likely to have better access to social information and food-sharing opportunities which may enhance their survival in years of low salmon abundance. Our results show that observable variation in the social environment is linked to variation in mortality risk, and highlight how sex differences in social effects on survival may be linked to sex differences in life-history evolution.

Supplementary methods

Supplementary analysis

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.

Purpose: The primary purpose of this prospective study was to identify the level of risk for psychosocial distress in families of children newly diagnosed with cancer. Additional study aims were to examine concordance among family and staff reports of psychosocial risk, changes in risk status over time, and to predict the use of psychosocial resources during the first months of treatment. Patients and Methods: Caregivers of 125 children newly diagnosed with cancer completed the Psychosocial Assessment Tool (PAT) at diagnosis (t1) and 3 to 6 months later (t2). Primary oncologists and nurses completed an analogous measure of perceived family psychosocial risk at t1 and t2. At t2, oncology social workers reported types and intensity of psychosocial interventions provided. Results: The PAT identified three subsets of families who presented with increasing levels of psychosocial risk at diagnosis. In general, there was moderate concordance among family, oncologist, and nurse reports of psychosocial risk. PAT scores at t1 predicted t2 PAT scores and psychosocial resource use at t2 beyond demographic or disease factors. Conclusion: A brief screening tool (PAT) is valuable in identifying psychosocial risk factors at diagnosis and is predictive of later use of psychosocial resources. As a next step in this research, the development of psychosocial interventions to match family risk level may be an effective and cost-efficient approach to working with families to address their concerns and promote short- and long-term adjustment.

Insulin-Dependent Diabetes Mellitus (IDDM) is an illness that affects the central nervous system (CNS). Both acute and chronic metabolic abnormalities relate to poorer neuropsychological functionin...

Objective To replicate an anomalous psychometric profile previously documented in children with Type 1 diabetes living in the mainland United States with a cross-cultural sample selected from Puerto Rico. Methods Ninety-three Spanish-speaking children (M age = 12.8 years) with Type 1 diabetes living in Puerto Rico were administered the Puerto Rican version of the Wechsler Intelligence Scale for Children-Revised (WISC-R). The factor structure of the Puerto Rican sample's WISC-R was then compared to that of a United States sample (n = 95) in which an anomalous factor structure in children with diabetes was first documented. Results As in the United States sample, a four-factor IQ structure was obtained. Instead of the traditional three-factor structure of the WISC-R, the Perceptual Organization factor split into a Spatial Conceptual factor and an anomalous Visual Discrimination factor. Conclusions Results support previous findings and suggest anomalies in the psychometric profiles of children with Type 1 diabetes. Cross-cultural replication of the anomalous IQ factor structure, and atypical visual discrimination, suggests that differences are illness-related, and consideration may therefore be warranted when administering some subtests of the Wechsler scales to children with Type 1 diabetes.

Summary The ability of the commercial tree shelter Growtube® and a perforated sheet metal shelter (Mauri) to improve the growth and survival of seedlings of Casuarina cristata, Eucalyptus moluccana and Melaleuca linariifolia was tested on the Darling Downs in south-east Queensland. The 0.9 m high tree shelters were removed after 2 years and at this time tree survival was unaffected by shelter type for all 3 species. Over a 44-month period, neither shelter improved the height growth of C. cristata or E. moluccana. Growtubes significantly (P 0.05). The early deterioration of the growtubes would have decreased their ability to create a beneficial microclimate, leading to the absence of any height increases for C. cristata and E. moluccana and small and non...

Supplementary methods and discussion for Inzani et al. Spontaneous abortion in banded mongoose

Supplementary methods and discussion for Inzani et al. Spontaneous abortion in banded mongoose

FROM Prof. Jack's Review of Muller's “Physics and Meteorology,” in your issue of August 4, I infer that he is not aware that an earlier edition of that valuable book was translated into English more than than twenty years ago, and formed one of the volumes of Bailliere's Scientific Library.