Alarm Pheromones and Chemical Communication in Nymphs of the Tropical Bed Bug Cimex hemipterus (Hemiptera: Cimicidae)

The recent resurge of bed bug infestations (Cimex spp.; Cimicidae) and their resistance to commonly used pesticides calls for alternative methods of control. Pheromones play an important role in environmentally sustainable methods for the management of many pest insects and may therefore be applicable for the control of bed bugs. The tropical bed bug, Cimex hemipterus, is a temporary ectoparasite on humans and causes severe discomfort. Compared to the common bed bug, Cimex lectularius, little is known about the chemical signalling and pheromone-based behaviour of the tropical species. Here, we show that the antennal morphology and volatile emission of C. hemipterus closely resembles those of C. lectularius and we test their behavioural responses to conspecific odour emissions. Two major volatiles are emitted by male, female and nymph C. hemipterus under stress, (E)-2-hexenal and (E)-2-octenal. Notably, nymph emissions show contrasting ratios of these compounds to adults and are further characterized by the addition of 4-oxo-(E)-2-hexenal and 4-oxo-(E)-2-octenal. The discovery of this nymph pheromone in C. hemipterus is potentially the cause of a repellent effect observed in the bio-tests, where nymph odours induce a significantly stronger repellent reaction in conspecifics than adult odours. Our results suggest that pheromone-based pest control methods developed for C. lectularius could be applicable to C. hemipterus, with the unique nymph blend showing promising practical properties

Poverty related risk for potentially preventable hospitalisations among children in Taiwan

<p>Abstract</p> <p>Background</p> <p>This study investigated the incidence of potentially preventable hospitalisations in the first two years of life among children in the National Health Insurance (NHI) system of Taiwan. It also examined income disparities in potentially preventable hospitalisations across four economic categories: below a government-established poverty line and low-, middle-, and upper-income. Five major diseases causing potentially preventable hospitalisations were investigated: gastroenteritis and dehydration, asthma and chronic bronchitis, acute upper respiratory infections, lower respiratory infections, and acute injuries and poisonings.</p> <p>Methods</p> <p>NHI data on enrolee registrations and use of ambulatory and hospital care by all children born between July 1, 2003 and June 30, 2004 (n = 218,158) was used for the study. The negative binomial regression method was used to identify factors associated with total inpatient care and the severity level for various types of potentially preventable hospitalisations during the first two years of life.</p> <p>Results</p> <p>This study found high inpatient expenses for lower respiratory infections for children in all income categories. Furthermore, results from the multivariate analysis indicate that children in the lowest economic category used inpatient care to a much greater extent than better-off children for problems considered potentially avoidable through primary prevention or through timely outpatient care. This was especially true for acute injuries and poisonings and for lower respiratory infections. On average, and controlling for other variables, a child in poverty spent 6.1 times more days in inpatient care for acute injuries and poisonings (p < 0.01) and 2.7 times more days for lower respiratory infections (p < 0.01) before age two, compared with a similarly-aged high-income child. The results also suggest a connection between economic status and the severity of a condition causing a potentially avoidable hospital admission. On average, length of stay for each admission for gastroenteritis and dehydration for children in poverty was 1.3 times that for high-income children (p < 0.01). Both the ratios for lower respiratory infections and for acute upper respiratory infections were 1.2 (p < 0.01 for both).</p> <p>Conclusions</p> <p>There were high hospital admission rates and lengths of stays for lower respiratory infections among young children in all income categories. Hospital care use of young children in the poorest category was significantly higher for acute injuries and poisonings as well as for lower respiratory infections, compared with those of better-off children. The findings suggest the need for increased attention to these two disease types. It particularly calls for more research on the causes of high hospital care use for lower respiratory infections and on the reasons for large economic disparities in hospital care use for acute injuries and poisonings.</p

Functional identity versus species richness: herbivory resistance in plant communities

The resistance of a plant community against herbivore attack may depend on plant species richness, with monocultures often much more severely affected than mixtures of plant species. Here, we used a plant–herbivore system to study the effects of selective herbivory on consumption resistance and recovery after herbivory in 81 experimental grassland plots. Communities were established from seed in 2002 and contained 1, 2, 4, 8, 16 or 60 plant species of 1, 2, 3 or 4 functional groups. In 2004, pairs of enclosure cages (1 m tall, 0.5 m diameter) were set up on all 81 plots. One randomly selected cage of each pair was stocked with 10 male and 10 female nymphs of the meadow grasshopper, Chorthippus parallelus. The grasshoppers fed for 2 months, and the vegetation was monitored over 1 year. Consumption resistance and recovery of vegetation were calculated as proportional changes in vegetation biomass. Overall, grasshopper herbivory averaged 6.8%. Herbivory resistance and recovery were influenced by plant functional group identity, but independent of plant species richness and number of functional groups. However, herbivory induced shifts in vegetation composition that depended on plant species richness. Grasshopper herbivory led to increases in herb cover at the expense of grasses. Herb cover increased more strongly in species-rich mixtures. We conclude that selective herbivory changes the functional composition of plant communities and that compositional changes due to selective herbivory depend on plant species richness

Diacylglycerol-Stimulated Endocytosis of Transferrin in Trypanosomatids Is Dependent on Tyrosine Kinase Activity

Small molecule regulation of cell function is an understudied area of trypanosomatid biology. In Trypanosoma brucei diacylglycerol (DAG) stimulates endocytosis of transferrin (Tf). However, it is not known whether other trypanosomatidae respond similarly to the lipid. Further, the biochemical pathways involved in DAG signaling to the endocytic system in T. brucei are unknown, as the parasite genome does not encode canonical DAG receptors (e.g. C1-domains). We established that DAG stimulates endocytosis of Tf in Leishmania major, and we evaluated possible effector enzymes in the pathway with multiple approaches. First, a heterologously expressed glycosylphosphatidylinositol phospholipase C (GPI-PLC) activated endocytosis of Tf 300% in L. major. Second, exogenous phorbol ester and DAGs promoted Tf endocytosis in L. major. In search of possible effectors of DAG signaling, we discovered a novel C1-like domain (i.e. C1_5) in trypanosomatids, and we identified protein Tyr kinases (PTKs) linked with C1_5 domains in T. brucei, T. cruzi, and L. major. Consequently, we hypothesized that trypanosome PTKs might be effector enzymes for DAG signaling. General uptake of Tf was reduced by inhibitors of either Ser/Thr or Tyr kinases. However, DAG-stimulated endocytosis of Tf was blocked only by an inhibitor of PTKs, in both T. brucei and L. major. We conclude that (i) DAG activates Tf endocytosis in L. major, and that (ii) PTKs are effectors of DAG-stimulated endocytosis of Tf in trypanosomatids. DAG-stimulated endocytosis of Tf may be a T. brucei adaptation to compete effectively with host cells for vertebrate Tf in blood, since DAG does not enhance endocytosis of Tf in human cells

Quantitative Computed Tomography in COPD: Possibilities and Limitations

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease that is characterized by chronic airflow limitation. Unraveling of this heterogeneity is challenging but important, because it might enable more accurate diagnosis and treatment. Because spirometry cannot distinguish between the different contributing pathways of airflow limitation, and visual scoring is time-consuming and prone to observer variability, other techniques are sought to start this phenotyping process. Quantitative computed tomography (CT) is a promising technique, because current CT technology is able to quantify emphysema, air trapping, and large airway wall dimensions. This review focuses on CT quantification techniques of COPD disease components and their current status and role in phenotyping COPD

Benefits for Dominant Red Deer Hinds under a Competitive Feeding System: Food Access Behavior, Diet and Nutrient Selection

Social dominance is widely known to facilitate access to food resources in many animal species such as deer. However, research has paid little attention to dominance in ad libitum access to food because it was thought not to result in any benefit for dominant individuals. In this study we assessed if, even under ad libitum conditions, social rank may allow dominant hinds to consume the preferred components of food. Forty-four red deer hinds (Cervus elaphus) were allowed to consume ad libitum meal consisting of pellets of sunflower, lucerne and orange, and seeds of cereals, corn, cotton, and carob tree. The meal was placed only in one feeder, which reduced accessibility to a few individuals simultaneously. During seven days, feeding behavior (order of access, time to first feeding bout, total time spent feeding, and time per feeding bout) were assessed during the first hour. The relative abundance of each meal component was assessed at times 0, 1 and 5 h, as well as its nutritional composition. Social rank was positively related to the amount of time spent feeding during the 1st h (P = 0.048). Selection indices were positively correlated with energy (P = 0.018 during the 1st h and P = 0.047 from 1st to 5th) and fat (only during the 1st h; P = 0.036), but also negatively with certain minerals. Thus, dominant hinds could select high energy meal components for longer time under an ad libitum but restricted food access setting. Selection indices showed a higher selectivity when food availability was higher (1st hour respect to 1st to 5th). Finally, high and low ranking hinds had longer time per feeding bout than mid ones (P = 0.011), suggesting complex behavioral feeding tactics of low ranking social ungulates

Passive and Motivated Perception of Emotional Faces: Qualitative and Quantitative Changes in the Face Processing Network

Emotionally expressive faces are processed by a distributed network of interacting sub-cortical and cortical brain regions. The components of this network have been identified and described in large part by the stimulus properties to which they are sensitive, but as face processing research matures interest has broadened to also probe dynamic interactions between these regions and top-down influences such as task demand and context. While some research has tested the robustness of affective face processing by restricting available attentional resources, it is not known whether face network processing can be augmented by increased motivation to attend to affective face stimuli. Short videos of people expressing emotions were presented to healthy participants during functional magnetic resonance imaging. Motivation to attend to the videos was manipulated by providing an incentive for improved recall performance. During the motivated condition, there was greater coherence among nodes of the face processing network, more widespread correlation between signal intensity and performance, and selective signal increases in a task-relevant subset of face processing regions, including the posterior superior temporal sulcus and right amygdala. In addition, an unexpected task-related laterality effect was seen in the amygdala. These findings provide strong evidence that motivation augmentsco-activity among nodes of the face processing network and the impact of neural activity on performance. These within-subject effects highlight the necessity to consider motivation when interpreting neural function in special populations, and to further explore the effect of task demands on face processing in healthy brains

Linking Employee Stakeholders to Environmental Performance: The Role of Proactive Environmental Strategies and Shared Vision

Drawing on the natural-resource-based view (NRBV), we propose that employee stakeholder integration is linked to environmental performance through firms’ proactive environmental strategies, and that this link is contingent on shared vision. We tested our model with a cross-country and multi-industry sample. In support of our theory, results revealed that firms’ proactive environmental strategies translated employee stakeholder integration into environmental performance. This relationship was pronounced for high levels of shared vision. Our findings demonstrate that shared vision represents a key condition for advancing the corporate greening agenda through proactive environmental strategies. We discuss implications for the CSR and the environmental management literatures, with a particular focus on the NRBV and stakeholder integration debates

A systematic review on integration mechanisms in human and animal health surveillance systems with a view to addressing global health security threats

Lymphatic filariasis and onchocerciasis are neglected tropical diseases (NTDs) targeted for elimination by mass (antifilarial) drug administration. These drugs are predominantly active against the microfilarial progeny of adult worms. New drugs or combinations are needed to improve patient therapy and to enhance the effectiveness of interventions in persistent hotspots of transmission. Several therapies and regimens are currently in (pre-)clinical testing. Clinical trial simulators (CTSs) project patient outcomes to inform the design of clinical trials but have not been widely applied to NTDs, where their resource-saving payoffs could be highly beneficial. We demonstrate the utility of CTSs using our individual-based onchocerciasis transmission model (EPIONCHO-IBM) that projects trial outcomes of a hypothetical macrofilaricidal drug. We identify key design decisions that influence the power of clinical trials, including participant eligibility criteria and post-treatment follow-up times for measuring infection indicators. We discuss how CTSs help to inform target product profiles