The human polyomavirus, JCV, uses serotonin receptors to infect cells

The human polyomavirus, JCV, causes the fatal demyelinating disease progressive multifocal leukoencephalopathy in immunocompromised patients. We found that the serotonergic receptor 5HT2AR could act as the cellular receptor for JCV on human glial cells. The 5HT2A receptor antagonists inhibited JCV infection, and monoclonal antibodies directed at 5HT2A receptors blocked infection of glial cells by JCV, but not by SV40. Transfection of 5HT2A receptor-negative HeLa cells with a 5HT2A receptor rescued virus infection, and this infection was blocked by antibody to the 5HT2A receptor. A tagged 5HT2A receptor colocalized with labeled JCV in an endosomal compartment following internalization. Serotonin receptor antagonists may thus be useful in the treatment of progressive multifocal leukoencephalopathy.     

Allometry of alarm calls: black-capped chickadees encode information about predator size

Many animals produce alarm signals when they detect a potential predator, but we still know little about the information contained in these signals. Using presentations of 15 species of live predators, we show that acoustic features of the mobbing calls of black-capped chickadees (Poecile atricapilla) vary with the size of the predator. Companion playback experiments revealed that chickadees detect this information and that the intensity of mobbing behavior is related to the size and threat of the potential predator. This study demonstrates an unsuspected level of complexity and sophistication in avian alarm calls.     

Biochar applications enhance the phytoextraction potential of Salix smithiana [Willd.] (willow) in heavily contaminated soil: potential for a sustainable remediation method?

Journal of Soils and Sediments - The combination of chemostabilization and phytoextraction provide an affordable and environmentally effective remediation technology for the heavy metals in...     

Seeing below the surface: making soil processes visible to Ugandan smallholder farmers through a constructivist and experiential extension approach

Ugandan smallholder farmers need to feed a growing population, but their efforts are hampered by declining soil fertility rates. Agricultural extension can facilitate farmers’ access to new practices and technologies, yet farmers are understandably often hesitant to adopt new behaviors. New knowledge assimilation is an important component of behavior change that is often overlooked or poorly addressed by current extension efforts. We implemented a Fertility Management Education Program (FMEP) in central Uganda to investigate smallholder farmers’ existing soil knowledge and their assimilation of new scientific concepts into their knowledge framework. Qualitative data were collected through participant observation, farmer interviews, and focus groups, and coded for using a priori and emergent themes. Our exploration revealed some notable similarities between farmers’ soil knowledge and scientific concepts, particularly in regards to soil health concepts, a discovery that could facilitate communication between extension agents and farmers. However, certain scientific concepts are either unknown to farmers or discordant with existing soil knowledge; these concepts are unlikely to be assimilated by farmers without convincing and concerted extension efforts. Importantly, we found that the combination of new scientific knowledge and hands-on experimentation with novel practices gave farmers far greater confidence in implementing improved soil management practices. Our study provides evidence that extension programs should engage directly with farmers’ existing soil knowledge to develop their understanding of key biological concepts and confidence in implementing improved practices.     

On (not) knowing where your food comes from: meat,mothering and ethical eating

Knowledge is a presumed motivator for changed consumption practices in ethical eating discourse: the consumer learns more about where their food comes from and makes different consumption choices. Despite intuitive appeal, scholars are beginning to illuminate the limits of knowledge-focused praxis for ethical eating. In this paper, we draw from qualitative interviews and focus groups with Toronto mothers to explore the role of knowledge in conceptions of ethical foodwork. While the goal of educating children about their food has become central to Canadian and American discourses of “good” mothering, we identify a paradoxical maternal expectation surrounding meat consumption: (1) to raise informed child consumers who know where their food comes from, and (2) to protect children from the harsh realities of animal slaughter. Rather than revealing the story behind the meat on a child’s plate, mothers seek to shield children from knowledge of meat production. Our analysis of the child consumer contributes to ethical eating scholarship and illuminates a larger paradox surrounding knowledge of meat in an industrialized food system. In the practice of feeding children, mothers confront the visceral discomforts of meat consumption; their reactions speak to discordant feelings involved with eating meat in a setting far-removed from the lives and deaths of animals. Ultimately, the paper illustrates the limits of consumer-focused strategies for food-system change that call on individual mothers to educate young consumers and protect childhood innocence, all while getting ethically-sourced meals on the table.     

Social Apoptosis in Varroa Mite Resistant Western Honey Bees (Apis mellifera)

Honey bees are eusocial animals that exhibit both individual and social immune responses, which influence colony health. This is especially well-studied regarding the mite Varroa destructor Anderson and Trueman (Parasitiformes: Varroidae), a parasite of honey bee brood and disease vector. Varroa was introduced relatively recently to Apis mellifera L. (Hymenoptera: Apidae) and is a major driver of the catastrophic die-off of honey bee colonies in the last decade. In contrast, the original host species, Apis cerana Fabricius (Hymenoptera: Apidae) is able to survive mite infestations with little effect on colony health and survival. This resilience is due in part to a newly identified social immune response expressed by developing worker brood. Varroa infested female A. cerana brood experience delayed development and eventually die in a process called ‘social apoptosis’. Here, an individual’s susceptibility to Varroa results in colony level resistance. We tested for the presence of the social apoptosis trait in two Varroa resistant stocks of A. mellifera (Pol-line and Russian) with different selection histories and compared them to a known Varroa-susceptible stock (Italian). We assessed the survival and development of worker brood reared in either highly or lightly infested host colonies, then receiving one of three treatments: uninfested, experimentally inoculated with a Varroa mite, or wounded to simulate Varroa damage. We found that response to treatment was only differentiated in brood reared in lightly infested host colonies, where experimentally infested Russian honey bees had decreased survival relative to the mite-susceptible Italian stock. This is the first evidence that social apoptosis can exist in Western honey bee populations.