Differential responses of vertebrate and invertebrate herbivores to traits of New Zealand subalpine shrubs

Plant traits are influenced by herbivore diet selection, but little is known about how traits are affected by different types of herbivores. We related eight traits of 27 subalpine shrub species in South Island, New Zealand, to damage of these shrubs by introduced red deer (Cervus elaphus) and native invertebrate herbivores using phylogenetically explicit modeling. Deer preferentially consumed species that grew quickly, were low in foliar tannins, or had high leaf area per unit mass. However, these traits did not trade off against each other; rather, they could be related to different multivariate defense strategies. Although the proportion of leaves damaged by leaf-chewing invertebrates also increased with stem growth, invertebrates did not damage the same fast growing species as those preferred by deer. Other traits may also be important in determining herbivore preferences, as suggested by the high proportion of variation in herbivory explained by phylogeny. Last, we found that the composition of invertebrate herbivore communities was more similar among closely related shrubs, and consequently, the range of invertebrate-plant associations may change if introduced deer shift plant composition toward slow-growing species. Overall, our results demonstrate the importance of herbivore type and coevolved interactions for the adaptive significance of plant traits.     

The evolution of sociality in small,carnivorous marsupials: the lek hypothesis revisited

One of the few mammal species reported to have a mating system of lek promiscuity is the tree-hollow nesting marsupial, the agile antechinus, Antechinus agilis. Past conclusions about its mating system have been based on seasonal changes in social group size, sex-specific nest switching and space use. Thermoregulation has also been suggested as an explanation for variation in social behaviour in this species and its relatives. We tested predictions of the lekking and thermoregulation hypotheses to explain sociality in cavity nesting antechinuses using published data, and new data on brown and subtropical antechinuses. We found that across four species, social group size is negatively correlated with daily minimum temperature, but not with timing of breeding. Females have a matrilineal fission–fusion social system, which continues during the brief mating season, and males range increasingly further throughout their lives, contacting as many females as possible in nests. Males show no indication of fission–fusion sociality. All evidence in species other than A. agilis, and some data on A. agilis, indicate a mating system of scramble polygyny, and not lek promiscuity. We conclude that across species, thermoregulation is the main reason for seasonal variation in nesting group size in both sexes.     

A comparative study of an innate immune response in Lamprologine cichlid fishes

Social interactions facilitate pathogen transmission and increase virulence. Therefore, species that live in social groups are predicted to suffer a higher pathogen burden, to invest more heavily in immune defence against pathogens, or both. However, there are few empirical tests of whether social species indeed invest more heavily in immune defence than non-social species. In the current study, we conducted a phylogenetically controlled comparison of innate immune response in Lamprologine cichlid fishes. We focused on three species of highly social cichlids that live in permanent groups and exhibit cooperative breeding (Julidochromis ornatus, Neolamprologus pulcher and Neolamprologus savoryi) and three species of non-social cichlids that exhibit neither grouping nor cooperative behaviour (Telmatochromis temporalis, Neolamprologus tetracanthus and Neolamprologus modestus). We quantified the innate immune response by injecting wild fishes with phytohaemagglutinin (PHA), a lectin that causes a cell-mediated immune response. We predicted that the three highly social species would show a greater immune reaction to the PHA treatment, indicating higher investment in immune defence against parasites relative to the three non-social species. We found significant species-level variation in immune response, but contrary to our prediction, this variation did not correspond to social system. However, we found that immune response was correlated with territory size across the six species. Our results indicate that the common assumption of a positive relationship between social system and investment in immune function may be overly simplistic. We suggest that factors such as rates of both in-group and out-group social interactions are likely to be important mediators of the relationship between sociality and immune function.     

Simultaneous Concentration of Bovine Viruses and Agricultural Zoonotic Bacteria from Water Using Sodocalcic Glass Wool Filters

Infiltration and runoff from manured agricultural fields can result in livestock pathogens reaching groundwater and surface waters. Here, we measured the effectiveness of glass wool filters to simultaneously concentrate enteric viruses and bacteria of bovine origin from water. The recovery efficiencies were determined for bovine viral diarrhea virus types 1 and 2, bovine rotavirus group A, bovine coronavirus, poliovirus Sabin III, toxigenic Escherichia coli ,and Campylobacter jejuni seeded into water with three different turbidity levels (0.5, 215, and 447 NTU). Twenty liters of dechlorinated tap water (pH 7) were seeded with the test organisms, and then passed through a glass wool filter using a peristaltic pump (flow rate = 1 liter min^?1). Retained organisms were eluted from the filters by passing beef extract-glycine buffer (pH 9.5) in the direction opposite of sample flow. Recovered organisms were enumerated by qPCR except for C. jejuni, which was quantified by culture. Mean recovery efficiencies ranged from 55 to 33 % for the bacteria and 58 to 16 % for the viruses. Using bootstrapping techniques combined with Analysis of Variance, recovery efficiencies were found to differ among the pathogen types tested at the two lowest turbidity levels; however, for a given pathogen type turbidity did not affect recovery except for C. jejuni. Glass wool filtration is a cost-effective method for concentrating several waterborne pathogens of bovine origin simultaneously, although recovery may be low for some specific taxa such as bovine viral diarrhea virus 1.     

Speaking without words: A meta-analysis of over 70 years of research on the power of nonverbal cues in job interviews

What candidates say in an interview is important—but so is how they say it. We draw on dual-process theory to explain why interviewers rely on individuals' dynamic and static nonverbal cues to evaluate performance with quick, implicit inferences (System 1 processing). Yet, it remains unclear which cues most influence interviewers' judgments and whether moderators affecting interviewers' reliance on System 1 thinking (e.g., interview structure, modality, duration, and interviewee gender) impact the relationship between nonverbal cues and interview ratings. We performed the first meta-analysis to address these questions, integrating findings across 63 studies (N = 4868). The nonverbal cues demonstrating the strongest association with interview performance were professional appearance (ρ = .62), eye contact (ρ = .45), and head movement (ρ = .43). Moderator analyses highlight the persistent power of nonverbal cues, as the results were largely unaffected by interview structure, modality, or duration. Experimental design did play a role, as did interviewees' gender, with stronger effects for certain nonverbal cues (e.g., facial expressions and professional appearance) for women than men, conveying interviewers' reliance on gender-based stereotypes when judging their performance. Overall, these results suggest nonverbal cues and characteristics are an important influence on job applicants' success in employment interviews.     

Ammonia and greenhouse gas emissions from a subtropical wheat field under different nitrogen fertilization strategies

Minimizing soil ammonia (NH₃) and nitrous oxide (N₂O) emission factors (EFs) has significant implications in regional air quality and greenhouse gas (GHG) emissions besides nitrogen (N) nutrient loss. The aim of this study was to investigate the impacts of different N fertilizer treatments of conventional urea, polymer-coated urea, ammonia sulfate, urease inhibitor (NBPT, N-(n-butyl) thiophosphoric triamide)-treated urea, and nitrification inhibitor (DCD, dicyandiamide)-treated urea on emissions of NH₃ and GHGs from subtropical wheat cultivation. A field study was established in a Cancienne silt loam soil. During growth season, NH₃ emission following N fertilization was characterized using active chamber method whereas GHG emissions of N₂O, carbon dioxide (CO₂), and methane (CH₄) were by passive chamber method. The results showed that coated urea exhibited the largest reduction (49%) in the EF of NH₃-N followed by NBPT-treated urea (39%) and DCD-treated urea (24%) over conventional urea, whereas DCD-treated urea had the greatest suppression on N₂O-N (87%) followed by coated urea (76%) and NBPT-treated urea (69%). Split fertilization of ammonium sulfate-urea significantly lowered both NH₃-N and N₂O-N EF values but split urea treatment had no impact over one-time application of urea. Both NBPT and DCD-treated urea treatments lowered CO₂-C flux but had no effect on CH₄-C flux. Overall, application of coated urea or urea with NPBT or DCD could be used as a mitigation strategy for reducing NH₃ and N₂O emissions in subtropical wheat production in Southern USA.     

A balancing act: Optimizing free chlorine contact time to minimize iodo-DBPs, NDMA, and regulated DBPs in chloraminated drinking water

Many drinking water treatment plants in the U.S. have switched from chlorination to chloramination to lower levels of regulated trihalomethane (THM) and haloacetic acid (HAA) disinfection byproducts (DBPs) in drinking water and meet the current regulations. However, chloramination can also produce other highly toxic/carcinogenic, unregulated DBPs: iodo-acids, iodo-THMs, and N-nitrosodimethylamine (NDMA). In practice, chloramines are generated by the addition of chlorine with ammonia, and plants use varying amounts of free chlorine contact time prior to ammonia addition to effectively kill pathogens and meet DBP regulations. However, iodo-DBPs and nitrosamines are generally not considered in this balancing of free chlorine contact time. The goal of our work was to determine whether an optimal free chlorine contact time could be established in which iodo-DBPs and NDMA could be minimized, while keeping regulated THMs and HAAs below their regulatory limits. The effect of free chlorine contact time was evaluated for the formation of six iodo-trihalomethanes (iodo-THMs), six iodo-acids, and NDMA during the chloramination of drinking water. Ten different free chlorine contact times were examined for two source waters with different dissolved organic carbon (DOC) and bromide/iodide. For the low DOC water at pH 7 and 8, an optimized free chlorine contact time of up to 1 h could control regulated THMs and HAAs, as well as iodo-DBPs and NDMA. For the high DOC water, a free chlorine contact time of 5 min could control iodo-DBPs and NDMA at both pHs, but the regulated DBPs could exceed the regulations at pH 7.