Division of labor in work shifts by leaf-cutting ants

Foraging rhythms in eusocial insects are determined by the colony´s overall pattern. However, in leaf-cutting ant workers, individual rhythms are not fully synchronized with the colonies’ rhythm. The colony as a whole is nocturnal, since most worker activity takes place at night; however some workers forage during the day. Previous studies in individualized ants suggest nocturnal and diurnal workers coexistence. Here observations within the colony, in leaf-cutting ants, showed that workers have differential foraging time preference, which interestingly is associated to body size and differential leaf transportation engagement. Nocturnal ants are smaller and less engaged in leaf transportation whereas diurnal ants are bigger and more engaged in leaf carriage. Mechanisms underlying division of labor in work shifts in ants are still unknown but much can be extrapolated from honeybees; another social system bearing a similar pattern. A collective organization like this favors constant exploitation of food sources while preserving natural individual rhythm patterns, which arise from individual differences, and thermal tolerance, given by the size polymorphism presented by this species.

“This Gig Is Not for Women”: Gender Stereotyping in Online Hiring

This study examines gender segregation in the context of the so-called gig economy. In particular, it explores the role that stereotypes about male and female occupations play in sorting men and women into different jobs in an online freelance marketplace. The findings suggest that gender stereotypes are particularly salient in online hiring because employers typically contract for short-term, relatively low-value jobs based on limited information about job applicants. These conditions trigger the use of cognitive shortcuts about intrinsic gender characteristics linked to different skills and occupations. The results corroborate that female candidates are less likely to be hired for male-typed jobs (e.g., software development) but more likely to be hired for female-typed jobs (e.g., writing and translation) than equally qualified male candidates. Further, the study investigates three mechanisms predicted to attenuate the female penalty in male-typed jobs. The penalty is found to be self-reinforcing, as it perpetuates gender imbalances in worker activity across job categories that strengthen the sex typing of occupations.

Machinic dispossession and augmented despotism: Digital work in an Amazon warehouse

Amazon e-commerce operations rely upon the living labor of thousands of workers. In the company’s warehouses, barcodes allow commodities to be construed as information to be managed. Work is thus mediated and organized digitally, as algorithms assign tasks and surveil workers. But it would be futile to analyze the technical organization of labor without studying the authoritarian nature of work under capitalist relations. Interviews with workers and managers unearth the material and cultural infrastructures that underpin Amazon labor. Early Italian operaismo, or workerist theory, offers a framework to analyze digital capitalism’s strategies to secure workers’ cooperation with machinery. Algorithms datafy worker activity and incorporate it in machinery. Management enacts a form of despotism mediated and augmented by digital tools and cultures. The technical and political rationalities deployed in the warehouse aim at satiating digital capitalism’s appetite for the labor of others.

Sources of intraspecific variation in the collective tempo and synchrony of ant societies

Populations of independently oscillating agents can sometimes synchronize. In the context of animal societies, conspicuous synchronization of activity is known in some social insects. However, the causes of variation in synchrony within and between species have received little attention. We repeatedly assessed the short-term activity cycle of ant colonies (Temnothorax rugatulus) and monitored the movements of individual workers and queens within nests. We detected persistent differences between colonies in the waveform properties of their collective activity oscillations, with some colonies consistently oscillating much more erratically than others. We further demonstrate that colony crowding reduces the rhythmicity (i.e., the consistent timing) of oscillations. Workers in both erratic and rhythmic colonies spend less time active than completely isolated workers, but workers in erratic colonies oscillate out of phase with one another. We further show that the queen’s absence can impair the ability of colonies to synchronize worker activity and that behavioral differences between queens are linked with the waveform properties of their societies.

Monitoring of Pathogenic Bioaerosols in Beef Slaughter Facilities Based on Air Sampling and Airflow Modeling

HighlightsSignificant bioaerosol concentrations were detected in beef slaughter facilitiesAirflow was modeled in beef facilities and potential pathogens were trackedResults indicate transport of bioaerosols toward chiller with final food productNew ventilation designs indicate that plant sanitation can be improvedAdditional studies are required to verify effectiveness of new ventilation Abstract. and Shiga toxin producing (STEC) have long been recognized as pathogens of concern in meat products due to the prevalence of these microorganisms in the gastrointestinal tract and hide of livestock. Bacterial ingestion due to contaminated food products causes a great economic burden from the hospitalization and death of those who become infected. Recently, aerosolized bacteria have been recognized as a threat to human health and shelf life of food. In beef processing facilities, the majority of harmful bacteria are introduced by the cattle. Heating, ventilation, and air conditioning (HVAC) systems can harbor and transport these microscopic organisms. Salmonella and STEC cause 78 billion dollars lost every year due to contaminated food. During the harvesting process, these pathogens may become aerosolized from the carcasses by various mechanisms, including worker activity and airflow from HVAC systems. Although bacteria are robust creatures, environmental conditions including ventilation can be manipulated to disrupt their proliferation. In this study, one rural and one small beef facility were examined. High air volume wetted wall cyclone bioaerosol samplers capable of collecting and concentrating bioaerosols in a liquid effluent were used during the entire processing at bleeding, de-limbing, de-hiding, washing, and chiller locations. Bioaerosols were analyzed using microbial plating, quantitative Polymerase Chain Reaction, and microbiome analysis. Total bacteria counts, STEC, and concentrations were enumerated in the air and critical areas were identified. and STEC were found to increase with each passing day in the facility, as well, total counts and STEC increased between morning and afternoon phases of processing. Significant differences in total counts and temperature were found at different locations in the facilities. Blueprints were obtained from the examined facilities and the cattle processing floors were modeled using computational fluid dynamics. The airflow created from the HVAC systems was found to have a significant effect on the spread of bioaerosols. Similarities were found between the collected concentrations of bioaerosols and particle traces in the modeled facilities. Finally, new ventilation models were generated to significantly increase the sanitation of the beef slaughtering process. Keywords: Airflow pattern, Beef processing facilities, Bioaerosols, Computational fluid dynamics modeling (CFD), Displacement ventilation, Wetted Wall Cyclone (WWC).