Geomorphological control on boulder transport and coastal erosion before, during and after an extreme extra-tropical cyclone

Extreme wave events in coastal zones are principal drivers of geomorphic change. Evidence of boulder entrainment and erosional impact during storms is increasing. However, there is currently poor time coupling between pre- and post-storm measurements of coastal boulder deposits. Importantly there are no data reporting shore platform erosion, boulder entrainment and/or boulder transport during storm events – rock coast dynamics during storm events are currently unexplored. Here, we use high-resolution (daily) field data to measure and characterise coastal boulder transport before, during and after the extreme Northeast Atlantic extra-tropical cyclone Johanna in March 2008. Forty-eight limestone fine-medium boulders (n = 46) and coarse cobbles (n = 2) were tracked daily over a 0.1 km2 intertidal area during this multi-day storm. Boulders were repeatedly entrained, transported and deposited, and in some cases broken down (n = 1) or quarried (n = 3), during the most intense days of the storm. Eighty-one percent (n = 39) of boulders were located at both the start and end of the storm. Of these, 92% were entrained where entrainment patterns were closely aligned to wave parameters. These data firmly demonstrate rock coasts are dynamic and vulnerable under storm conditions. No statistically significant relationship was found between boulder size (mass) and net transport distance. Graphical analyses suggest that boulder size limits the maximum longshore transport distance but that for the majority of boulders lying under this threshold, other factors influence transport distance. Paired analysis of 20 similar sized and shaped boulders in different morphogenic zones demonstrates that geomorphological control affects entrainment and transport distance – where net transport distances were up to 39 times less where geomorphological control was greatest. These results have important implications for understanding and for accurately measuring and modelling boulde

Comparing the effectiveness of polymer debriding devices using a porcine wound biofilm model

Objective: Debridement to remove necrotic and/or infected tissue and promote active healing remains a cornerstone of contemporary chronic wound management. While there has been a recent shift toward less invasive polymer-based debriding devices, their efficacy requires rigorous evaluation.Approach: This study was designed to directly compare monofilament debriding devices to traditional gauze using a wounded porcine skin biofilm model with standardized application parameters. Biofilm removal was determined using a surface viability assay, bacterial counts, histological assessment, and scanning electron microscopy (SEM).Results: Quantitative analysis revealed that monofilament debriding devices outperformed the standard gauze, resulting in up to 100-fold greater reduction in bacterial counts. Interestingly, histological and morphological analyses suggested that debridement not only removed bacteria, but also differentially disrupted the bacterially-derived extracellular polymeric substance. Finally, SEM of post-debridement monofilaments showed structural changes in attached bacteria, implying a negative impact on viability.Innovation: This is the first study to combine controlled and defined debridement application with a biologically relevant ex vivo biofilm model to directly compare monofilament debriding devices.Conclusion: These data support the use of monofilament debriding devices for the removal of established wound biofilms and suggest variable efficacy towards biofilms composed of different species of bacteria

Evaluating forecasts of the evolution of the cloudy boundary layer using diurnal composites of radar and lidar observations

Observations of boundary-layer cloud have been made using radar and lidar at Chilbolton, Hampshire, UK. These have been compared with output from 7 different global and regional models. Fifty-five cloudy days have been composited to reveal the mean diurnal variation of cloud top and base heights, cloud thickness and liquid water path of the clouds. To enable like-for-like comparison between model and observations, the observations have been averaged on to the grid of each model. The composites show a distinct diurnal cycle in observed cloud; the cloud height exhibits a sinusoidal variation throughout the day with a maximum at around 1600 and a minimum at around 0700 UTC. This diurnal cycle is captured by six of the seven models analysed, although the models generally under-predict both cloud top and cloud base heights throughout the day. The two worst performing models in terms of cloud boundaries also have biases of around a factor of two in liquid water path; these were the only two models that did not include an explicit formulation for cloud-top entrainment

Eyes that bind us: Gaze leading induces an implicit sense of agency

Humans feel a sense of agency over the effects their motor system causes. This is the case for manual actions such as pushing buttons, kicking footballs, and all acts that affect the physical environment. We ask whether initiating joint attention – causing another person to follow our eye movement – can elicit an implicit sense of agency over this congruent gaze response. Eye movements themselves cannot directly affect the physical environment, but joint attention is an example of how eye movements can indirectly cause social outcomes. Here we show that leading the gaze of an on-screen face induces an underestimation of the temporal gap between action and consequence (Experiments 1 and 2). This underestimation effect, named ‘temporal binding,’ is thought to be a measure of an implicit sense of agency. Experiment 3 asked whether merely making an eye movement in a non-agentic, non-social context might also affect temporal estimation, and no reliable effects were detected, implying that inconsequential oculomotor acts do not reliably affect temporal estimations under these conditions. Together, these findings suggest that an implicit sense of agency is generated when initiating joint attention interactions. This is important for understanding how humans can efficiently detect and understand the social consequences of their actions

A Group-1 Grass Pollen Allergen Influences the Outcome of Pollen Competition in Maize

Worldwide, 400 million people suffer from hay fever and seasonal asthma. The major causative agents of these allergies are pollen specific proteins called the group-1 grass pollen allergens. Although details of their antigenicity have been studied for 40 years with an eye towards immunotherapy, their function in the plant has drawn scant attention. Zea m 1 constitutes a class of abundant grass pollen allergens coded for by several genes that loosen the walls of grass cells, including the maize stigma and style. We have examined the impact of a transposon insertion into one of these genes (EXPB1, the most abundant isoform of Zea m 1) on the production of Zea m 1 protein, pollen viability, and pollen tube growth, both in vitro and in vivo. We also examined the effect of the insertional mutation on the competitive ability of the pollen by experimentally varying the sizes of the pollen load deposited onto stigmas using pollen from heterozygous plants and then screening the progeny for the presence of the transposon using PCR. We found that the insertional mutation reduced the levels of Zea m 1 in maize pollen, but had no effect on pollen viability, in vitro pollen tube growth or the proportion of progeny sired when small pollen loads are deposited onto stigmas. However, when large pollen loads are deposited onto the stigmas, the transposon mutation is vastly underrepresented in the progeny, indicating that this major pollen allergen has a large effect on pollen tube growth rates in vivo, and plays an important role in determining the outcome of the pollen-pollen competition for access to the ovules. We propose that the extraordinary abundance (4% of the extractable protein in maize pollen) of this major pollen allergen is the result of selection for a trait that functions primarily in providing differential access to ovules

The Nandewar Volcano

The Miocene Nandewar Volcano in north-eastern New South Wales is composed of a suite of transitional alkaline eruptives and minor associated intrusives. The volcanics include minor hawaiites but are dominated by a mildly potassic lineage extending from hy-normative trachyandesites to comendites via tristanites and mafic to peralkaline trachytes. Although the trachyandesites, tristanites and trachytes (the main shield-forming sequence) are collectively the most abundant volcanics, alkali rhyolites comprise the most voluminous 'evolved' eruptive type. Peralkaline trachytes and comendites are relatively insignificant volumetrically. Olivine, Ca-rich pyroxene and amphibole display marked decreases in their 100 Mg/(Mg+Fe) ratios in the transition from trachyandesite to comendite, reflecting variation in host-rock compositions. The presence of tschermakitic Ca-rich pyroxenes and aluminian bronzite megacrysts in several trachyandesites indicates that their hosts experienced intratelluric crystallization at elevated pressures (~6 to 8 kb). Some plagioclase, olivine and titanomagnetite phenocrysts may also represent moderate-pressure cognate precipitates. Groundmass pyroxenes in some trachytes and comendites may be strongly acmitic, and this reflects the peralkaline character of those melts. Titanomagnetite is the dominant Fe-Ti oxide phase throughout the series, and only occasionally does it coexist with ilmenite. Fe-Ti oxide compositional data indicate that magmas spanning the spectrum trachyandesite to comendite generally crystallized under conditions of decreasing T and ƒo₂ which were broadly parallel with the FMQ synthetic buffer curve. However, some alkali rhyolites appear to have crystallized under significantly more oxidizing conditions. Crystallization of aenigmatite in the groundmass of peralkaline trachytes and comendites also reflects relatively strongly reducing conditions in the more 'evolved' variants and ns-bearing melts. In several specimens the presence of aenigmatite rimming titanomagnetite and ilmenite microphenocrysts provides some support for the existence of a 'no-oxide' field in T-ƒo₂ space

From gaze perception to social cognition: The shared-attention system

When two people look at the same object in the environment and are aware of each other’s attentional state, they find themselves in a shared-attention episode. This can occur through intentional or incidental signaling and, in either case, causes an exchange of information between the two parties about the environment and each other’s mental states. In this article, we give an overview of what is known about the building blocks of shared attention (gaze perception and joint attention) and focus on bringing to bear new findings on the initiation of shared attention that complement knowledge about gaze following and incorporate new insights from research into the sense of agency. We also present a neurocognitive model, incorporating first-, second-, and third-order social cognitive processes (the shared-attention system, or SAS), building on previous models and approaches. The SAS model aims to encompass perceptual, cognitive, and affective processes that contribute to and follow on from the establishment of shared attention. These processes include fundamental components of social cognition such as reward, affective evaluation, agency, empathy, and theory of mind