Direct anthelmintic effects of condensed tannins from diverse plant sources against Ascaris suum

Ascaris suum is one of the most prevalent nematode parasites in pigs and causes significant economic losses, and also serves as a good model for A. lumbricoides, the large roundworm of humans that is ubiquitous in developing countries and causes malnutrition, stunted growth and compromises immunity to other pathogens. New treatment options for Ascaris infections are urgently needed, to reduce reliance on the limited number of synthetic anthelmintic drugs. In areas where Ascaris infections are common, ethno-pharmacological practices such as treatment with natural plant extracts are still widely employed. However, scientific validation of these practices and identification of the active compounds are lacking, although observed effects are often ascribed to plant secondary metabolites such as tannins. Here, we extracted, purified and characterised a wide range of condensed tannins from diverse plant sources and investigated anthelmintic effects against A. suum in vitro. We show that condensed tannins can have potent, direct anthelmintic effects against A. suum, as evidenced by reduced migratory ability of newly hatched third-stage larvae and reduced motility and survival of fourth-stage larvae recovered from pigs. Transmission electron microscopy showed that CT caused significant damage to the cuticle and digestive tissues of the larvae. Furthermore, we provide evidence that the strength of the anthelmintic effect is related to the polymer size of the tannin molecule. Moreover, the identity of the monomeric structural units of tannin polymers may also have an influence as gallocatechin and epigallocatechin monomers exerted significant anthelmintic activity whereas catechin and epicatechin monomers did not. Therefore, our results clearly document direct anthelmintic effects of condensed tannins against Ascaris and encourage further in vivo investigation to determine optimal strategies for the use of these plant compounds for the prevention and/or treatment of ascariosis.

Differential interference effects of negative emotional states on subsequent semantic and perceptual processing

Past studies have revealed that encountering negative events interferes with cognitive processing of subsequent stimuli. The present study investigates whether negative events affect semantic and perceptual processing differently. Presentation of negative pictures produced slower reaction times than neutral or positive pictures in tasks that require semantic processing, such as natural or man-made judgments about drawings of objects, commonness judgments about objects, and categorical judgments about pairs of words. In contrast, negative picture presentation did not slow down judgments in subsequent perceptual processing (e.g., color judgments about words, size judgments about objects). The subjective arousal level of negative pictures did not modulate the interference effects on semantic or perceptual processing. These findings indicate that encountering negative emotional events interferes with semantic processing of subsequent stimuli more strongly than perceptual processing, and that not all types of subsequent cognitive processing are impaired by negative events.

Effects of noise and by-catch on a Danish harbour porpoise population

Ships and wind turbines generate noise, which can have a negative impact on marine mammal populations by scaring animals away. Effective modelling of how this affects the populations has to take account of the location and timing of disturbances. Here we construct an individual-based model of harbour porpoises in the Inner Danish Waters. Individuals have their own energy budgets constructed using established principles of physiological ecology. Data are lacking on the spatial distribution of food which is instead inferred from knowledge of time-varying porpoise distributions. The model produces plausible patterns of population dynamics and matches well the age distribution of porpoises caught in by-catch. It estimates the effect of existing wind farms as a 10% reduction in population size when food recovers fast (after two days). Proposed new wind farms and ships do not result in further population declines. The population is however sensitive to variations in mortality resulting from by-catch and to the speed at which food recovers after being depleted. If food recovers slowly the effect of wind turbines becomes negligible, whereas ships are estimated to have a significant negative impact on the population. Annual by-catch rates ≥10% lead to monotonously decreasing populations and to extinction, and even the estimated by-catch rate from the adjacent area (approximately 4.1%) has a strong impact on the population. This suggests that conservation efforts should be more focused on reducing by-catch in commercial gillnet fisheries than on limiting the amount of anthropogenic noise. Individual-based models are unique in their ability to take account of the location and timing of disturbances and to show their likely effects on populations. The models also identify deficiencies in the existing database and can be used to set priorities for future field research.

Effects of high hydrostatic pressure and chemical reduction on the emulsification properties of gum arabic

Gum arabic is widely used in the food industry as an additive, both as a thickener and an emulsifier. This study has compared the emulsification properties of two types of gums, KLTA (Acacia senegal) and GCA (Acacia seyal), both in their native/untreated forms and after exposure to high pressure (800 MPa). Further studies were undertaken to chemically modify the disulphide linkages present and to investigate the effects of their reduction on the diffusion of the carbohydrate materials. The emulsification properties of the gum samples were examined by determining the droplet size distribution in a ‘‘model’’ oil-in-water system. Results showed that high pressure treatment and chemical reduction of gums changed the emulsification properties of both gums. The high molecular weight component in arabinogalactanproteins (AGP/GP), and more ‘‘branched’’ carbohydrates present in gum arabic, may be responsible for the emulsification properties of GCA gum, indicating that the emulsification mechanisms for KLTA and GCA were different.

Counteracting the climate effects of volcanic eruptions using short-lived greenhouse gases

A large volcanic eruption might constitute a climate emergency, significantly altering global temperature and precipitation for several years. Major future eruptions will occur, but their size or timing cannot be predicted. We show, for the first time, that it may be possible to counteract these climate effects through deliberate emissions of short-lived greenhouse gases, dampening the abrupt impact of an eruption. We estimate an emission pathway countering a hypothetical eruption 3 times the size of Mount Pinatubo in 1991. We use a global climate model to evaluate global and regional responses to the eruption, with and without counteremissions. We then raise practical, financial, and ethical questions related to such a strategy. Unlike the more commonly discussed geoengineering to mitigate warming from long-lived greenhouse gases, designed emissions to counter temporary cooling would not have the disadvantage of needing to be sustained over long periods. Nevertheless, implementation would still face significant challenges.

Organic and conventional fertilizer effects on a tritrophic interaction: parasitism, performance and preference of Cotesia vestalis

Interest in sustainable farming methods that rely on alternatives to conventional synthetic fertilizers and pesticides is increasing. Sustainable farming methods often utilize natural populations of predatory and parasitic species to control populations of herbivores, which may be potential pest species. We investigated the effects of several types of fertilizer, including those typical of sustainable and conventional farming systems, on the interaction between a herbivore and parasitoid. The effects of fertilizer type on percentage parasitism, parasitoid performance, parasitoid attack behaviour and responses to plant volatiles were examined using a model Brassica system, consisting of Brassica oleracea var capitata, Plutella xylostella (Lepidoptera) larvae and Cotesia vestalis (parasitoid). Percentage parasitism was greatest for P. xylostella larvae feeding on plants that had received either a synthetic ammonium nitrate fertilizer or were unfertilized, in comparison to those receiving a composite fertilizer containing hoof and horn. Parasitism was intermediate on plants fertilized with an organically produced animal manure. Male parasitoid tibia length showed the same pattern as percentage parasitism, an indication that offspring performance was maximized on the treatments preferred by female parasitoids for oviposition. Percentage parasitism and parasitoid size were not correlated with foliar nitrogen concentration. The parasitoids did not discriminate between hosts feeding on plants in the four fertilizer treatments in parasitoid behaviour assays, but showed a preference for unfertilized plants in olfactometer experiments. The percentage parasitism and tibia length results provide support for the preference–performance hypothesis

On the microphysical effects of observed cloud edge charging

Liquid layer clouds are abundant globally. Lacking strong convection, they do not become electrified by the usual thunderstorm mechanisms of collisional electrification between hydrometeors of different phases. Instead, the background global circuit current flow in fair weather is largely unaffected by the layer cloud’s presence, and, if the layer cloud is extensive horizontally, the vertical fair weather conduction current passes through the cloud. A consequence of the vertical current flow is that, at the cloud-air boundary where there is a conductivity transition and droplets form or evaporate, droplet charging occurs. Charge can affect both droplet evaporation and droplet-droplet collisions. Using new radiosonde instrumentation, the charge observed at layer cloud edges is evaluated for both these microphysical droplet processes. This shows that the charging is more likely to affect collision processes than activation, for small droplets. Enhancing the collection efficiency of small droplets modifies their evolution and propagates through the size distribution to shorten the autoconversion timescale to rain drops, and the cloud radiative properties. Because the conduction current density is influenced by both external (e.g. solar modulation of high energy particles) and internal (e.g. ENSO) factors, current flow leading to layer cloud edge charging provides a possible route for expressing solar influences on the climate system and a teleconnection mechanism for communicating internal climate variability.

Local and landscape effects on bee functional guilds in pigeon pea crops in Kenya

Pollinators face many challenges within agricultural systems due to landscape changes and intensification which can affect resource availability that can impact pollination services. This paper examines pigeon pea pollination and considers how landscape context and agricultural intensification in terms of pesticide use affects the abundance of bees characterized by species guilds on crops. The study was conducted on six paired farms across a gradient of habitat complexity based on the distance of each farm from adjacent semi-natural vegetation in Kibwezi Sub-county, Kenya. The study found that farms which do not use insecticides in farm management, but are in close proximity to natural habitat have greater bee guild abundance, but at further distances, overall abundance is reduced with or without insecticide use. At 1 km landscape radius, the complexity of habitats but not patch size had a positive impact on the abundance of cavity nesting bees and mason bees, which can be attributed to the interspersion of the small-holder farms with semi-natural habitats across the landscapes producing mosaics of heterogeneous habitats. The study revealed the strongest relationships between fruit set and bee abundance to be with the carpenter bee, social bee and solitary bee guilds, which are among the most abundant bees visiting pigeon pea flowers in this system. Our findings provide the foundation for conservation efforts by identifying which bee guilds pollinated pigeon peas. From this study, we suggest managing the floral and nesting resources that would best support the most abundant crop pollinators, and also reducing insecticide application to the crop.

Production of milk foams by steam injection: the effects of steam pressure and nozzle design

Foam properties depend on the physico-chemical characteristics of the continuous phase, the method of production and process conditions employed; however the preparation of barista-style milk foams in coffee shops by injection of steam uses milk as its main ingredient which limits the control of foam properties by changing the biochemical characteristics of the continuous phase. Therefore, the control of process conditions and nozzle design are the only ways available to produce foams with diverse properties. Milk foams were produced employing different steam pressures (100-280 kPa gauge) and nozzle designs (ejector, plunging-jet and confined-jet nozzles). The foamability of milk, and the stability, bubble size and texture of the foams were investigated. Variations in steam pressure and nozzle design changed the hydrodynamic conditions during foam production, resulting in foams having a range of properties. Steam pressure influenced foam characteristics, although the net effect depended on the nozzle design used. These results suggest that, in addition to the physicochemical determinants of milk, the foam properties can also be controlled by changing the steam pressure and nozzle design.

Effects of a web-based personalized intervention on physical activity in European adults: a randomized controlled trial

Background: The high prevalence of physical inactivity worldwide calls for innovative and more effective ways to promote physical activity (PA). There are limited objective data on the effectiveness of Web-based personalized feedback on increasing PA in adults. Objective: It is hypothesized that providing personalized advice based on PA measured objectively alongside diet, phenotype, or genotype information would lead to larger and more sustained changes in PA, compared with nonpersonalized advice. Methods: A total of 1607 adults in seven European countries were randomized to either a control group (nonpersonalized advice, Level 0, L0) or to one of three personalized groups receiving personalized advice via the Internet based on current PA plus diet (Level 1, L1), PA plus diet and phenotype (Level 2, L2), or PA plus diet, phenotype, and genotype (Level 3, L3). PA was measured for 6 months using triaxial accelerometers, and self-reported using the Baecke questionnaire. Outcomes were objective and self-reported PA after 3 and 6 months. Results: While 1270 participants (85.81% of 1480 actual starters) completed the 6-month trial, 1233 (83.31%) self-reported PA at both baseline and month 6, but only 730 (49.32%) had sufficient objective PA data at both time points. For the total cohort after 6 months, a greater improvement in self-reported total PA (P=.02) and PA during leisure (nonsport) (P=.03) was observed in personalized groups compared with the control group. For individuals advised to increase PA, we also observed greater improvements in those two self-reported indices (P=.006 and P=.008, respectively) with increased personalization of the advice (L2 and L3 vs L1). However, there were no significant differences in accelerometer results between personalized and control groups, and no significant effect of adding phenotypic or genotypic information to the tailored feedback at month 3 or 6. After 6 months, there were small but significant improvements in the objectively measured physical activity level (P<.05), moderate PA (P<.01), and sedentary time (P<.001) for individuals advised to increase PA, but these changes were similar across all groups. Conclusions: Different levels of personalization produced similar small changes in objective PA. We found no evidence that personalized advice is more effective than conventional “one size fits all” guidelines to promote changes in PA in our Web-based intervention when PA was measured objectively. Based on self-reports, PA increased to a greater extent with more personalized advice. Thus, it is crucial to measure PA objectively in any PA intervention study.

Effects of coastal managed retreat on mercury biogeochemistry

We investigated the impact of managed retreat on mercury (Hg) biogeochemistry at a site subject to diffuse contamination with Hg. We collected sediment cores from an area of land behind a dyke one year before and one year after it was intentionally breached. These sediments were compared to those of an adjacent mudflat and a salt marsh. The concentration of total mercury (THg) in the sediment doubled after the dyke was breached due to the deposition of fresh sediment that had a smaller particle size, and higher pH. The concentration of methylmercury (MeHg) was 27% lower in the sediments after the dyke was breached. We conclude that coastal flooding during managed retreat of coastal flood defences at this site has not increased the risk of Hg methylation or bioavailability during the first year. As the sediment becomes vegetated, increased activity of Hg-methylating bacteria may accelerate Hg-methylation rate.

A review of the cognitive effects observed in humans following acute supplementation with flavonoids, and their associated mechanisms of action

Flavonoids are polyphenolic compounds found in varying concentrations in many plant-based foods. Recent studies suggest that flavonoids can be beneficial to both cognitive and physiological health. Long term flavonoid supplementation over a period of weeks or months has been extensively investigated and reviewed, particularly with respect to cognitive ageing and neurodegenerative disease. Significantly less focus has been directed towards the short term effects of single doses of flavonoids on cognition. Here, we review 21 such studies with particular emphasis on the subclass and dose of flavonoids administered, the cognitive domains affected by flavonoid supplementation, and the effect size of the response. The emerging evidence suggests that flavonoids may be beneficial to attention, working memory, and psychomotor processing speed in a general population. Episodic memory effects are less well defined and may be restricted to child or older adult populations. The evidence also points towards a dose-dependent effect of flavonoids, but the physiological mechanisms of action remain unclear. Overall, there is encouraging evidence that flavonoid supplementation can benefit cognitive outcomes within an acute time frame of 0–6 h. But larger studies, combining cognitive and physiological measures, are needed to strengthen the evidence base.

The relationship between size of living space and subjective well-being

Against a background of shrinking new homes and forebodings of “rabbit hutch Britain”, the relationship between size of living space and subjective well-being has never been more topical in the UK. Using the British Household Panel Survey (BHPS) and fixed effects regressions, this paper is the first to examine this relationship comprehensively. Two pathways are proposed between space and subjective well-being. First, space facilitates values and activities. Second, space signals wealth which in turn influences social status. It is proposed that wealth is a more important determinant of status for men than women, and that pathway two is therefore gendered. Part one of the paper examines the effect of a change in number of rooms per person on housing satisfaction and subjective well-being in the BHPS as a whole. Despite having a similar effect on the housing satisfaction of both genders, an increase in living space has only a (weak) positive linear effect on the life satisfaction and mental health of men. This suggests that space affects subjective well-being through pathway two, status. Part two of the paper tracks the housing satisfaction and subjective well-being over time of those individuals who move for “larger accommodation”. Consistent with various theories of adaptation, housing satisfaction increases in the year of the move; then decreases slightly before levelling out. Moving for “larger accommodation” has no positive impact on subjective well-being. Overall the results imply a weak positive relationship between size of living space and subjective well-being, but only for men.

Size matters: body size determines functional responses of ground beetle interactions

Understanding patterns in predator:prey systems and the mechanisms that underlie trophic interactions provides a basis for predicting community structure and the delivery of natural pest control services. The functional response of predators to prey density is a fundamental measure of interaction strength and its characterisation is essential to understanding these processes. We used mesocosm experiments to quantify the functional responses of five ground beetle species that represent common generalist predators of north-west European arable agriculture. We investigated two mechanisms predicted to be key drivers of trophic interactions in natural communities: predator:prey body size ratio and multiple predator effects. Our results show regularities in foraging patterns characteristic of similarly sized predators. Ground beetle attack rates increased and handling times decreased as the predator:prey body-mass ratio rose. Multiple predator effects on total prey consumption rates were sensitive to the identity of the interacting species but not prey density. The extent of interspecific interactions may be a result of differences in body mass between competing beetle species. Overall these results add to the growing evidence for the importance of size in determining trophic interactions and suggest that body mass could offer a focus on which to base the management of natural enemy assemblages.

Larger brain size indirectly increases vulnerability to extinction in mammals

Although previous studies have addressed the question of why large brains evolved, we have limited understanding of potential beneficial or detrimental effects of enlarged brain size in the face of current threats. Using novel phylogenetic path analysis, we evaluated how brain size directly and indirectly, via its effects on life-history and ecology, influences vulnerability to extinction across 474 mammalian species. We found that larger brains, controlling for body size, indirectly increase vulnerability to extinction by extending the gestation period, increasing weaning age, and limiting litter sizes. However, we found no evidence of direct, beneficial or detrimental, effects of brain size on vulnerability to extinction, even when we explicitly considered the different types of threats that lead to vulnerability. Order-specific analyses revealed qualitatively similar patterns for Carnivora and Artiodactyla. Interestingly, for Primates, we found that larger brain size was directly (and indirectly) associated with increased vulnerability to extinction. Our results indicate that under current conditions the constraints on life-history imposed by large brains outweigh the potential benefits, undermining the resilience of the studied mammals. Contrary to the selective forces that have favoured increased brain size throughout evolutionary history, at present, larger brains have become a burden for mammals.