Perception Of Environmental Cues Research Articles

Modeling antecedents of safety compliance of construction workers in Australia: a perspective of trait activation theory

PurposeConstruction workers’ safety compliance is attracting considerable critical attention as it plays a decisive role in improving safety on construction sites. This study applied the concept of differentiating safety compliance into deep compliance (DC) and surface compliance (SC) and relied on trait activation theory to investigate the effects of situational awareness (SA) and emotional intelligence (EI) on safety compliance.Design/methodology/approachCross-sectional survey data were collected from 239 construction workers in Australia, and these responses were statistically analyzed using the partial least squares structural equation modeling (PLS-SEM) to validate the proposed model.FindingsResults revealed that both EI and SA positively impacted DC and negatively impacted SC. Moreover, SA partially mediated the link between EI and two types of safety compliance (DC and SC). The outcomes showed that construction workers’ ability in regulating their emotions could influence their perception of environmental cues and the effectiveness of safety compliance behavior.Originality/valueThis study sheds light on investigating the antecedents of DC and SC from the perspective of trait activation theory. The findings also have practical implications, stating that construction site managers or safety professionals should consider providing training on construction workers’ EI and SA to enhance their willingness to expend conscious efforts in complying with safety rules and procedures, which can lead to improved safety outcomes.

Seasonality in Biological Rhythms in Scandinavian brown Bears.

Biological rhythms, such as rhythms in activity and body temperature, are usually highly synchronized and entrained by environmental conditions, such as photoperiod. However, how the expression of these rhythms changes during hibernation, when the perception of environmental cues is limited, has not yet been fully understood for all hibernators, especially in the wild. The brown bear (Ursus arctos) in Scandinavia lives in a highly seasonal environment and adapts to harsh winter conditions by exhibiting hibernation, characterized by reduced metabolism and activity. In this study, we aimed to explore the expression of biological rhythms in activity, body temperature and heart rate of free-ranging brown bears over the annual cycle, including active, hibernation and the transition states around den entry and exit. We found that rhythms in physiology and activity are mostly synchronized and entrained by the light-dark cycle during the bears’ active state with predominantly diel and ultradian rhythms for body temperature, activity and heart rate. However, during hibernation, rhythms in body temperature and heart rate were considerably slowed down to infradian rhythms, influenced by the amount of snow in the denning area, whereas rhythms in activity remained diel. Rhythms in the transition states when bears prepared for entering or coming out of hibernation state displayed a combination of infradian and diel rhythms, indicating the preparation of the body for the change in environmental conditions. These results reveal that brown bears adjust their biological rhythms to the seasonal environment they inhabit. Rhythms in physiology and activity show simultaneity during the active state but are partly disconnected from each other during hibernation, when bears are most sheltered from the environment.

Situation Awareness Levels to Evaluate the Usability of Augmented Feedback to Support Driving in an Unfamiliar Traffic Regulation

Driving in an unfamiliar traffic regulation using an unfamiliar vehicle configuration contributes to increase number of traffic accidents. In these circumstances, a driver needs to have what is referred to as ‘situation awareness’ (SA). SA is divided into (level 1) perception of environmental cues, (level 2) comprehension of the perceived cues in relation to the current situation and (level 3) projection of the status of the situation in the near future. On the other hand, augmented feedback (AF) is used to enhance the performance of a certain task. In Driving, AF can be provided to drivers via in-vehicle information systems. In this paper, we hypothesize that considering the SA levels when designing AF can reduce the driving errors and thus enhance road safety. To evaluate this hypothesis, we conducted a quantitative study to test the usability of a certain set of feedback and an empirical study using a driving simulator to test the effectiveness of that feedback in terms of improving driving performance, particularly at roundabouts and intersections in an unfamiliar traffic system. The results of the first study enhanced the ability of the in-vehicle information system to provide feedback considering SA levels. This information was incorporated into a driving simulator and provided to drivers. The results of the second study revealed that considering SA levels when designing augmented feedback significantly reduces the driving errors at roundabouts and intersections in an unfamiliar traffic regulation.

Efficient profiling of detergent-assisted membrane proteome in cyanobacteria

Membrane proteins play key roles in cellular functions like transport of molecules, perception of environmental cues, and signal transduction into the intracellular compartment. However, the profiling of membrane proteins is still a daunting task because of the hydrophobicity, restricting our knowledge of membrane proteins. Thus, we attempted to develop a novel detergent-based approach to uncover membrane proteins using cyanobacteria. We investigated the effect of five different detergents on the profiling of the cyanobacterial membrane proteome. The application of either amidosulfobetaine-14 (ASB14) or N-lauroylsarcosine (NL) doubled the number of the identified integral membrane proteins compared with the control. Extraction with ASB14 increased the number of transmembrane helices over four times. The quantitative index (mol%) of membrane proteins also increased from 13 to 22% when ASB14, NL, and benzyldimethyl-n-hexadecylammonium chloride (BAC) were used. ASB14 treatment was particularly useful for identifying membrane proteins with higher molecular weights (Mr), and the addition of BAC to the cyanobacterial membrane could identify the membrane proteins with acidic isoelectric points (pI). To validate the efficiency of the detergent-based proteomics, the functional membrane protein complexes involved in energy metabolism were selected as an example and shown to be successful with the combined data of ASB14, NL, and zwittergent 3-10 (ZW3-10). Taken together, we suggest that the use of a specific detergent and the subsequent combination of proteome data is critical for detailed profiling of cyanobacterial functional membrane proteins.

Calcium ions in the aquatic environment drive planarians to food

BackgroundEven subtle changes in environmental factors can exert behavioral effects on creatures, which may alter interspecific interactions and eventually affect the ecosystem. However, how changes in environmental factors impact complex behaviors regulated by neural processes is largely unknown. The freshwater planarian Dugesia japonica, a free-living flatworm, displays distinct behavioral traits mediated by sensitive perception of environmental cues. Planarians are thus useful organisms for examining interactions between environmental changes and specific behaviors of animals.ResultsHere we found that feeding behavior was suppressed when the concentration of ions in the breeding water was low, while other behaviors were unaffected, resulting in differences in population size. Notably, the decline in feeding behavior was reversed in an ion-concentration-dependent manner soon after the planarians were moved to ion-containing water, which suggests that ions in environmental water rapidly promote feeding behavior in planarians. Moreover, the concentration of ions in the environmental water affected the feeding behavior by modulating the sensitivity of the response to foods. Finally, we found that calcium ions in the aquatic environment were required for the feeding behavior, and exposure to higher levels of calcium ions enhanced the feeding behavior, showing that there was a good correlation between the concentration of calcium ions and the responsiveness of planarians to foods.ConclusionsEnvironmental calcium ions are indispensable for and potentiate the activity level of the feeding behavior of planarians. Our findings suggest that the ions in the aquatic environment profoundly impact the growth and survival of aquatic animals via modulating their neural activities and behaviors.

Molecular Mechanisms of Wing Polymorphism in Insects.

Many insects are capable of developing into either long-winged or short-winged (or wingless) morphs, which enables them to rapidly match heterogeneous environments. Thus, the wing polymorphism is an adaptation at the root of their ecological success. Wing polymorphism is orchestrated at various levels, starting with the insect's perception of environmental cues, then signal transduction and signal execution, and ultimately the transmitting of signals into physiological adaption in accordance with the particular morph produced. Juvenile hormone and ecdysteroid pathways have long been proposed to regulate wing polymorphism in insects, but rigorous experimental evidence is lacking. The breakthrough findings of ecdysone receptor regulation on transgenerational wing dimorphism in the aphid Acyrthosiphon pisum and of insulin signaling in the planthopper Nilaparvata lugens greatly broaden our understanding of wing polymorphism at the molecular level. Recently, the advent of high-throughput sequencing coupled with functional genomics provides powerful genetic tools for future insights into the molecular bases underlying wing polymorphism in insects.

Blow Your Nose, Shrimp! Unexpectedly Dense Bacterial Communities Occur on the Antennae and Antennules of Hydrothermal Vent Shrimp

In crustaceans, as in other animals, perception of environmental cues is of key importance for a wide range of interactions with the environment and congeners. Chemoreception involves mainly the antennae and antennules, which carry sensilla that detect water-borne chemicals. The functional importance of these as exchange surfaces in the shrimp's sensory perception requires them to remain free of any microorganism and deposit that could impair the fixation of odorant molecules on sensory neurons. We report here the occurrence of an unexpected dense bacterial colonization on surface of the antennae and antennules of four hydrothermal vent shrimp species. Microscopic observation, qPCR and 16S rRNA barcoding reveal the abundance, diversity and taxonomic composition of these bacterial communities, that are compared with those found on a related coastal shrimp. Bacterial abundances vary among species. Bacteria are almost absent in coastal shrimp, meanwhile they fully cover the antennal flagella in some hydrothermal vent species. Epsilon- and Gammaproteobacteria dominate the hydrothermal shrimp-associated communities, whereas Alphaproteobacteria and Bacteroidetes are dominant in the coastal ones. Bacteria associated with vent shrimp species are most similar to known chemoautotrophic sulfur-oxidizers. Potential roles of these bacteria on the hydrothermal shrimp antennae and antennules and on sensory functions are discussed.

Development of antennal sensilla of Tetragonisca angustula Latreille, 1811 (Hymenoptera: Meliponini) during pupation.

The antennal sensilla are sensory organs formed by a group of neurons and accessory cells, which allow perception of environmental cues, which play a role as mechanoreceptors and chemoreceptors. This study describes the post-embryonic development of the antennal sensilla of the stingless Tetragonisca angustula (Hymenoptera: Meliponini) workers. The development of the antennal sensilla begins in the transition stage of the pre-pupae to white-eyed pupae. The sensilla are completely developed at the black-eyed pupae stage, but they are covered by the old cuticle. The sensilla are exposed to the environment only in newly emerged workers of T. angustula, but it is possible that environmental stimuli can be recognized due to the pores in the old cuticle.

A comparative study of the antennal sensilla in corbiculate bees

SummarySensilla are the basic structures that allow the perception of environmental cues that play a role as mechanoreceptors, chemoreceptors, thermoreceptors and hygroreceptors associated with their morphology. Because bees have different degrees of sociability, they are a good model for the study of sensilla types and distribution linked with behaviour. This work identifies the types of sensilla in the antennae of bees with different degrees of sociability. The antennae of 18 species of bee were analysed with a scanning electron microscope. Trichoid and placoid sensilla are present in all antennomers of the species studied. The honey bee Apis mellifera and bumble bee Bombus pauloensis workers have higher diversity and sensillum distribution in comparison with males. In stingless bees, species of Meliponaare representative of a homogeneous group for sensilla types and distribution. The types and distribution of sensilla in the antennae of bees seems to be associated with the degree of sociability.

SKB1/PRMT5‐mediated histone H4R3 dimethylation of Ib subgroup bHLH genes negatively regulates iron homeostasis in Arabidopsis thaliana

Histone modifications play critical roles in the perception of environmental cues by plants. Here, we report that Shk1 binding protein 1 (SKB1/AtPRMT5), which catalyzes the symmetric dimethylation of histone H4R3 (H4R3sme2), is involved in iron homeostasis in Arabidopsis. The SKB1 lesion mutant exhibited higher iron accumulation in shoots and greater tolerance to iron deficiency than the wild type. The expression of SKB1 was not affected by iron, but the level of H4R3sme2 mediated by SKB1 was related to iron status in plants. We showed by chromatin immunoprecipitation (ChIP) and genome-wide ChIP-seq that SKB1 associated with the chromatin of the Ib subgroup bHLH genes (AtbHLH38, AtbHLH39, AtbHLH100 and AtbHLH101), and symmetrically dimethylated histone H4R3. The quantity of SKB1 that associated with chromatin of the Ib subgroup bHLH genes and the level of H4R3sme2 corresponded to the iron status of plants (higher with increased iron supply and lower when iron was removed). We conclude that SKB1-mediated H4R3sme2 regulates iron homeostasis in Arabidopsis in the context of increasing or decreasing expression of Ib subgroup bHLH genes. Iron deficiency may cause an increase in the disassociation of SKB1 from chromatin of the bHLH genes and a decrease in the level of H4R3sme2, thereby elevating their transcription and enhancing iron uptake. Our findings provide new insight into the molecular mechanisms of iron homeostasis in strategy I plants.

Genetic networks involved in poplar root response to low nitrogen

Perception of environmental cues and adaptation to changing environmental conditions are crucial for survival of sessile organisms like plants. This is even more important for woody perennial species like trees that can occupy a site for thousands of years. We have previously shown that under low nitrogen (LN), poplar trees display a vigorous and long-lasting root growth associated with global transcriptomic reprogramming and an activation of hierarchical genetic networks. Here we use computational analysis to better understand the network among the genes showing distinct chronological patterns of expression during the response. Our analyses confirm the previous findings, define new potential signaling pathways and the possible downstream targets of these signaling events.

The role of the nervous system in aging and longevity

The role of the nervous system in aging and longevity

Altered stomatal dynamics in ascorbate oxidase over-expressing tobacco plants suggest a role for dehydroascorbate signalling

Control of stomatal aperture is of paramount importance for plant adaptation to the surrounding environment. Here, we report on several parameters related to stomatal dynamics and performance in transgenic tobacco plants (Nicotiana tabacum L., cv. Xanthi) over-expressing cucumber ascorbate oxidase (AO), a cell wall-localized enzyme of uncertain biological function that oxidizes ascorbic acid (AA) to monodehydroascorbic acid which dismutates yielding AA and dehydroascorbic acid (DHA). In comparison to WT plants, leaves of AO over-expressing plants exhibited reduced stomatal conductance (due to partial stomatal closure), higher water content, and reduced rates of water loss on detachment. Transgenic plants also exhibited elevated levels of hydrogen peroxide and a decline in hydrogen peroxide-scavenging enzyme activity. Leaf ABA content was also higher in AO over-expressing plants. Treatment of epidermal strips with either 1 mM DHA or 100 microM hydrogen peroxide resulted in rapid stomatal closure in WT plants, but not in AO-over-expressing plants. This suggests that signal perception and/or transduction associated with stomatal closure is altered by AO over-expression. These data support a specific role for cell wall-localized AA in the perception of environmental cues, and suggest that DHA acts as a regulator of stomatal dynamics.

Live Analysis of Endodermal Layer Formation Identifies Random Walk as a Novel Gastrulation Movement

During gastrulation, dramatic movements rearrange cells into three germ layers expanded over the entire embryo [1-3]. In fish, both endoderm and mesoderm are specified as a belt at the embryo margin. Mesodermal layer expansion is achieved through the combination of two directed migrations. The outer ring of precursors moves toward the vegetal pole and continuously seeds mesodermal cells inside the embryo, which then reverse their movement in the direction of the animal pole [3-6]. Unlike mesoderm, endodermal cells internalize at once and must therefore adopt a different strategy to expand over the embryo [7, 8]. With live imaging of YFP-expressing zebrafish endodermal cells, we demonstrate that in contrast to mesoderm, internalized endodermal cells display a nonoriented/noncoordinated movement fit by a random walk that rapidly disperses them over the yolk surface. Transplantation experiments reveal that this behaviour is largely cell autonomous, induced by TGF-beta/Nodal, and dependent on the downstream effector Casanova. At midgastrulation, endodermal cells switch to a convergence movement. We demonstrate that this switch is triggered by environmental cues. These results uncover random walk as a novel Nodal-induced gastrulation movement and as an efficient strategy to transform a localized cell group into a layer expanded over the embryo.