Mosquitoes, particularly Aedes aegypti, pose significant public health risks by transmitting diseases like dengue, zika and chikungunya. Bacillus thuringiensis var. israelensis (BTI) is a crucial larvicide targeting mosquitoes while sparing other organisms and the environment. This study evaluated the effects of sublethal BTI doses on Ae. aegypti larvae regarding mortality, development, adult emergence and size, using a wide-area spray application in an urban neighbourhood. Laboratory experiments with four BTI concentrations (0, 0.008, 0.02 and 0.04 ppm) assessed compensatory and over compensatory responses. The spray achieved over 90% larval mortality within 48 h, but accumulating sublethal doses could trigger compensatory and over compensatory effects, enhancing the fitness of survivors. A dose–response relationship was evident, with higher BTI concentrations leading to increased mortality, reduced longevity and fewer pupae. BTI exposure also skewed the sex ratio towards males and altered adult sizes, potentially affecting population dynamics and vectorial capacity. These findings highlight the effectiveness of BTI in Ae. aegypti control and the importance of understanding compensation, overcompensation and density-dependent effects. While wide-area BTI applications can reach inaccessible breeding sites and offer potent mosquito control, careful consideration of ecological and evolutionary consequences is crucial.

Most studies of sex education center on local Anglo-Euro-American contexts, tracing the origin of sex education to a coordinated response to the spread of venereal diseases. These neglect the circumstances in which sex education developed in the developing world between the 1950s and 1980s: a growing collective anxiety about rising birth rates that culminated in the adoption of population control measures. This paper examines the “glocal” history of population-centered sex education in the developing world in the 1960s and 1970s, through the case study of Singapore. Examining the emergence of the first sex education curriculum in post-independence Singapore between 1966 and 1973, I argue that population-centered sex education that emerged in Singapore was intimately connected with global population politics. Analysis of how the policy was formulated shows that the Singapore state reacted to both domestic and global concerns. In connecting local developments to global contexts, this paper gestures toward the possibilities of studying the global history of population-centered sex education.

Following domestication of the cat about 5000 years ago, it followed man into many areas of the world. The vast resources available in urban environments have led to increasing numbers of free-roaming cats on the streets. The high population density of these cats and, in many cases, the lack of suitable nourishment and veterinary care, is conducive to their poor condition of health. They are frequently perceived as a nuisance to human society. This article surveys the different methods of management of free-roaming cat populations, focusing on the urban environment, and discusses the animal welfare implications and the advantages and disadvantages of each method.

Three types of fertility control, surgical sterilization, hormonal chemosterilization, and immunosterilization, are reviewed with regard to their potential for controlling problematic populations of carnivores. The fertility control agent and delivery protocol of choice may vary considerably according to: (i) the reason for control; (ii) the degree, urgency and duration of population reduction required; (iii) concerns about ethics and public opinion; and (iv) the status, population dynamics, social structure, mating system, size, behaviour and reproductive endocrinology of the target animals. Although they are often perceived and advocated as more preferable methods of population control than lethal approaches, it is important that wildlife managers as well as members of the public realize that the ethical acceptability of the various fertility control techniques may differ considerably - and that numerous questions regarding their effectiveness, humaneness and ecological safety remain unanswered.

In Callitrichid primates, offspring remain in their natal group beyond the age of sexual maturity, increasing the group's inclusive fitness by cooperatively rearing their siblings. Contraception of the dominant female in these groups may alter the associated costs and benefits of this cooperative rearing in such a way that offspring themselves attempt to breed when a period longer than the normal inter-birth interval of one year has elapsed. Contraception of the dominant female may also induce changes in socio-sexual interactions between group members, which can lead to increased aggression after a short period. In this study, we investigated the occurrence of aggression in 16 captive groups of golden-headed lion tamarins (Leontopithecus chrysomelas) under three conditions: 1) no contraception used; 2) contraception used and offspring younger than one year present within the group; and 3) contraception used and all offspring in the group older than one year. We found that the probability of aggression occurring in the groups was best predicted by logistic regression models containing the factors ‘group size ‘ and ‘overall proportion of males ‘ or ‘number of sons ‘. Aggression was more likely in larger groups with a high proportion of males or a large number of sons. This effect was significantly stronger for groups in which all offspring were older than one year. Absence of dispersal opportunities and differences in male and female reproductive strategies may explain the observed patterns. The increased instability of large non-breeding groups presents a problem when using long-term contraceptive methods and should be taken into account when making decisions on the most suitable population-control procedures.

In southwestern England, red deer, Cervus elaphus, are culled by rifle (‘stalking’) or by hunting with hounds (‘hunting’). We compare the welfare costs of the two culling methods. Observations of hunts revealed that likely stressors such as close proximity to humans and hounds, active pursuit, noise, obstruction and physical restraint prior to despatch were very common. Other stressors, such as wounding, were rare. The blood profiles of hunted deer were compared both with injured deer, which were put down because they were thought to be suffering, and with stags stalked in the rutting season, when mature males rapidly lose weight and may be damaged in fights. Extensively hunted deer did not differ from severely injured deer in measures of muscle disruption: in hunted deer measures of red blood cell damage and psychological stress were higher. Hunted stags killed during the rut showed markedly higher levels of measures of blood and muscle cell disruption, psychological stress and fat reserve mobilization than stalked stags killed during this season. Estimates of wounding rates by stalkers showed that 11 per cent of deer required two or more shots to kill, 7 per cent took 2—15 min to die and 2 per cent escaped wounded. Overall, we judged that the welfare costs associated with hunting red deer were higher than those associated with stalking, and reducing the welfare costs associated with hunting was much less feasible than reducing those associated with stalking.

The self-replicating machine has high utility by virtue of its universal construction properties and its productive capacity for exponential growth. Their capacity is unrivalled. They can be deployed to the Moon to industrialize it using local in-situ resources in the short term to open up the solar system and thence deployed on interstellar spacecraft to explore the entire Galaxy by exploiting in-situ stellar system resources. Nevertheless, there are significant concerns regarding the inherent safety of self-replicating machines. We consider the general problem of runaway population growth in physical self-replicating machines to prevent the grey goo problem, the number of offspring spawned by self-replicating machines may be controlled at a genetic level. We adopt a biologically-inspired approach based on telomeres, DNA endcaps that are progressively shortened during cellular replication. This acts as a counter that imposes a limit to the number of replication cycles (Hayflick limit). By examining the biological process in detail, we can obtain some insights in implementing similar mechanisms in self-replicating machines. In particular, we find that counting mechanisms are vulnerable to cancerous runaway.

This article moves past high politics and the most prominent activists to explore the daily, intimate practice of international movement building by mid-level fieldworkers within the International Planned Parenthood Federation (IPPF) during its first decade of existence (1952–62). It illustrates how fieldworkers and the IPPF’s practitioner-oriented newsletter Around the World attempted to bridge the ideological and geographic diversity of the family planning movement and connect with advocates around the world through an emotive narrative of suffering, love, and global humanity, reinforced by affective bonds and women’s volunteerism. The story of global family planning must thus be seen not only as part of the history of eugenics, population control, and feminism, but also as part of the longer trajectory of maternalist humanitarianism. This mid-twentieth century version of maternalist humanitarianism built on earlier traditions but also incorporated concepts of human rights, critiques of dominant gender and sexual norms, and an official commitment to local self-determination in the context of decolonization movements. Still, the organization was plagued by the problems that shape humanitarianism more broadly, including the difficulty of moving past colonialist discourses, deeply rooted feelings of racial superiority, and the contradictions inherent in attempts to impose an impossible ideal of political neutrality in a politically complex world. Looking at the history of global family planning from this perspective thus helps us understand how the different traditions, intimate relationships, and practical experiences mid-level actors bring to their work shape the broader process of international movement building, beyond high-level political and ideological activism.

This article explores the discursive functioning of education policies, bringing into consideration community perspectives regarding policy enactment in contemporary China. With the intention of building upon ongoing discussions surrounding both the conceptions and purposes of policy sociology, we critically analyse policies directly related to the education of migrant children living in and around China's largest urban centres, with a specific focus on those implemented in Beijing. We emphasize two important aspects that previous studies of China's education policies have tended to underplay given their focus on social-economic perspectives. The first argument is that education policies have an underlying agenda that extends beyond that of simply addressing the educational needs of migrant children – evidenced through the discursive functions of policy texts. The second argument is related and seeks to raise questions about who is best served by these policies and for whom these policies are intended.

Addressing what affects predation among caterpillars, we conducted an experiment in a Bornean rain forest on 212 clay models of Tortricidae caterpillars (the herbivore) and 53 trees of Kopsia pauciflora (the host), located either in the open or under closed canopies. We predicted that the frequency of predatory attacks towards caterpillars increases (1) in canopy gaps and (2) on leaves damaged by herbivory, but (3) decreases among caterpillars that wrap their body in leaves. Each plant with caterpillar models was consecutively allocated to one of four treatments: caterpillars artificially rolled in leaves vs caterpillars on unrolled leaves, and caterpillars on artificially damaged vs undamaged leaves. Each time, caterpillar models were placed on the plants for 48 h, and then replaced with new models that were subjected to a new treatment. On average, our caterpillar models had a 21% chance of being attacked per 24 h. More attacks were performed by insects (81.6%) than birds. The attack frequency did not depend on the canopy cover or on leaf damage, but decreased among models rolled in leaves. This pattern was mainly attributable to insect attacks, which were also more frequent than bird attacks. Overall, the Tortricidae caterpillars seem to suffer comparable predation rates in the open and under closed canopies irrespective of the herbivory damage of leaves, but their leaf-rolling behaviour might reduce predation.