A note on facultative kleptoparasitism in Prionyx kirbii (Hymenoptera: Sphecidae) as a consequence of multi-specific shared nesting site, with description of its prepupa

Observations of a female of Prionyx kirbii at an aggregation of Stizus continuus revealed an alternative nesting behaviour of the first wasp due to the presence of the second one. The overlap of some resources (prey, kind of soil) allowed P. kirbii to act as a kleptoparasite of S. continuus. The observed female often re-used as nests pre-existing S. continuus emergence holes, but no S. continuus nests. The prey were obtained sometimes by stealing the grasshoppers from S. continuus nests and/or by attacking the females while carrying the prey. From a review of interspecific kleptoparasitism among sphecoid wasps it appears that family Sphecidae includes the highest number of facultative parasitism cases and this finding is discussed. In addition, the description of the prepupa of P. kirbii is given and is shown to be in agreement with the description of the mature larvae of the other species of the genus

The Role of the Dorsolateral Prefrontal Cortex during Sequence Learning is Specific for Spatial Information

Many studies have implicated the dorsolateral prefrontal cortex in the acquisition of skill, including procedural sequence learning. However, the specific role it performs in sequence learning has remained uncertain. This type of skill has been intensively studied using the serial reaction time task. We used three versions of this task: a standard task where the position of the stimulus cued the response; a non-standard task where the color of the stimulus was related to the correct response; and a combined task where both the color and position simultaneously cued the response. We refer to each of these tasks based upon the cues available for guiding learning as position, color and combined tasks. The combined task usually shows an enhancement of skill acquisition, a result of being driven by two simultaneous and congruent cues. Prior to the performance of each of these tasks the function of the dorsolateral prefrontal cortex was disrupted using repetitive transcranial magnetic stimulation. This completely prevented learning within the position task, while sequence learning occurred to a similar extent in both the color and combined tasks. So, following prefrontal stimulation the expected learning enhancement in the combined task was lost, consistent with only a color cue being available to guide sequence learning in the combined task. Neither of these effects was observed following stimulation at the parietal cortex. Hence the critical role played by the dorsolateral prefrontal cortex in sequence learning is related exclusively to spatial cues. We suggest that the dorsolateral prefrontal cortex operates over the short term to retain and manipulate spatial information to allow cortical and subcortical structures to learn a predictable sequence of actions. Such functions may emerge from the broader role the dorsolateral prefrontal cortex has in spatial working memory. These results argue against the dorsolateral prefrontal cortex constituting part of the neuronal substrate responsible for general aspects of implicit or explicit sequence learning.Medicin

One-Dimensional Modeling of Mechanical and Friction Losses Distribution in a Four-Stroke Internal Combustion Engine

[EN] As the road transport accounts between 15%-18% of worldwide CO2 emissions, the automotive sector has a deep commitment to mitigate global warming. Consequently, stricter regulations have been adopted by the European Union and worldwide to reduce that big impact. Approximately, 10% of the energy generated by fuel combustion in the engine is destined to the auxiliaries components activation and the movement of mechanical elements with relative motion between themselves. A reduction on that figure or alternatively a mechanical efficiency improvement can be directly translated on target alignment. The aim of this work is developing a model to predict the mechanical and friction losses and its distribution in a four-stroke direct injection-diesel engine and simulating different strategies, which increment the engine efficiency. A 1D model has been developed and fitted in GT-SUITE based on the experimental results of a 1.6-L diesel engine. Additionally, a description of the tribological performance has been realized in different parts of the engine where friction is present. Finally, the engine friction maps have been broken down in order to quantify the friction losses produced in the piston ring assembly, crankshaft bearings, and valvetrainTormos, B.; Martín, J.; Blanco-Cavero, D.; Jiménez-Reyes, AJ. (2020). One-Dimensional Modeling of Mechanical and Friction Losses Distribution in a Four-Stroke Internal Combustion Engine. Journal of Tribology. 142(1). https://doi.org/10.1115/1.4044856S142

Complex-to-predict generational shift between nested and clustered organization of individual prey networks in digger wasps

Although diet has traditionally been considered to be a property of the species or populations as a whole, there is nowadays extensive knowledge that individual specialization is widespread among animal populations. Nevertheless, the factors determining the shape of interactions within food webs remain largely undiscovered, especially in predatory insects. We used an aggregation of the digger wasp Bembix merceti to 1) analyse patterns of individual prey use across three flying seasons in a network-based context; and 2) test the effect of four potential factors that might explain network topologies (wasp mass, nest spatial distribution, simultaneous nest-provisioning, prey availability). Inter-individual diet variation was found in all three years, under different predator-prey network topologies: Individuals arranged in dietary clusters and displayed a checkerboard pattern in 2009, but showed nestedness in 2008 and 2010. Network topologies were not fully explained by the tested factors. Larger females consumed a higher proportion of the total number of prey species captured by the population as a whole, in such a way that nested patterns may arise from mass-dependent prey spectrum width. Conversely, individuals with similar body mass didn't form clusters. Nested patterns seemed to be associated with a greater availability of the main prey species (a proxy for reduced intra-specific competition). Thus, according with theory, clusters seemed to appear when competition increased. On the other hand, the nests of the individuals belonging to a given cluster were not more closely located, and neither did individuals within a cluster provision their nests simultaneously. Thus, a female-female copying behaviour during foraging was unlikely. In conclusion, wasp populations can maintain a considerable individual variation across years under different food web organizations. The tested factors only partially accounted for the shift in network properties, and new analyses should be carried out to elucidate how diet network topologies arise in wasp populations. © 2014 Ballesteros et al.This work was supported by the Projects SA094A09 and SA010A06 (Junta de Castilla y León) and CGL2010-16730 (MICINN). CP was funded by a post-doctoral contract within the Program JAE-Doc ‘‘Junta para la Ampliacio´n de Estudios,’’ funded by the Spanish Research Council (CSIC) and the FSE.Peer Reviewe

Time to reconcile research findings and clinical practice on upper limb neurorehabilitation

The problemIn the field of upper limb neurorehabilitation, the translation from research findings to clinical practice remains troublesome. Patients are not receiving treatments based on the best available evidence. There are certainly multiple reasons to account for this issue, including the power of habit over innovation, subjective beliefs over objective results. We need to take a step forward, by looking at most important results from randomized controlled trials, and then identify key active ingredients that determined the success of interventions. On the other hand, we need to recognize those specific categories of patients having the greatest benefit from each intervention, and why. The aim is to reach the ability to design a neurorehabilitation program based on motor learning principles with established clinical efficacy and tailored for specific patient's needs. Proposed solutionsThe objective of the present manuscript is to facilitate the translation of research findings to clinical practice. Starting from a literature review of selected neurorehabilitation approaches, for each intervention the following elements were highlighted: definition of active ingredients; identification of underlying motor learning principles and neural mechanisms of recovery; inferences from research findings; and recommendations for clinical practice. Furthermore, we included a dedicated chapter on the importance of a comprehensive assessment (objective impairments and patient's perspective) to design personalized and effective neurorehabilitation interventions. ConclusionsIt's time to reconcile research findings with clinical practice. Evidence from literature is consistently showing that neurological patients improve upper limb function, when core strategies based on motor learning principles are applied. To this end, practical take-home messages in the concluding section are provided, focusing on the importance of graded task practice, high number of repetitions, interventions tailored to patient's goals and expectations, solutions to increase and distribute therapy beyond the formal patient-therapist session, and how to integrate different interventions to maximize upper limb motor outcomes. We hope that this manuscript will serve as starting point to fill the gap between theory and practice in upper limb neurorehabilitation, and as a practical tool to leverage the positive impact of clinicians on patients' recovery

Interindividual variability of the modulatory effects of repetitive transcranial magnetic stimulation on cortical excitability

Repetitive transcranial magnetic stimulation (rTMS) appears to have effects on cortical excitability that extend beyond the train of rTMS itself. These effects may be inhibitory or facilitatory and appear to depend on the frequency, intensity, duration and intertrain interval of the rTMS. Many studies assume facilitatory effects of high-frequency rTMS and inhibitory effects of low-frequency rTMS. Nevertheless, the interindividual variability of this modulation of cortical excitability by rTMS has not been systematically investigated. In this study, we applied 240 pulses of rTMS at 90% of the subjects' motor threshold to their motor cortex at different frequencies (1, 10, 15 and 20 Hz) and examined the effects on motor evoked potentials (frequency tuning curve). Although the averaged group data showed a frequency-dependent increase in cortical excitability, each subject had a different pattern of frequency tuning curve, i.e. a different modulatory effect on cortical excitability at different rTMS frequencies. The interindividual variability of these modulatory effects was still high, though less so, when the number of rTMS pulses was increased to 1600. These findings illustrate the degree of variability of the rTMS effects in the human brain.Supported in part by grants from the Cellular Science Research Foundation, Yoshida Science Foundation, Japan North America Medical Exchange Foundation, the Stanley Vada Foundation, the National Alliance for Research and Schizophrenia and Depression, and the National Institute of Mental Health (RO1MH57980)Medicin

Post-mating shift towards longer-chain cuticular hydrocarbons drastically reduces female attractiveness to males in a digger wasp

[EN]Females of most aculeate Hymenoptera mate only once and males are therefore under a strong competitive pressure which is expected to favour the evolution of rapid detection of virgin females. In several bee species, the cuticular hydrocarbon (CHC) profile exhibited by virgin females elicits male copulation attempts. However, it is still unknown how widespread this type of sexual communication is within Aculeata. Here, we investigated the use of CHCs as mating cues in the digger wasp Stizus continuus, which belongs to the family (Crabronidae) from within bees arose. In field experiments, unmanipulated, recently emerged virgin female dummies promptly elicit male copulation attempts, whereas 1–4 days old mated females dummies were still attractive but to a much lesser extent. In contrast, old (10–15 days) mated female dummies did not attract males at all. After hexane-washing, attractiveness almost disappeared but could be achieved by adding CHC extracts from virgin females even on hexane-washed old mated females. Thus, the chemical base of recognition of females as appropriate mating partner by males is coded in their CHC profile

Antidepressant Effects of High and Low Frequency Repetitive Transcranial Magnetic Stimulation to the Dorsolateral Prefrontal Cortex

Repetitive transcranial magnetic stimulation(rTMS) has antidepressant effects in patients withmajor depressive disorder. The mechanisms of ac-tion and optimal stimulation parameters remainunclear. To test the hypothesis that rTMS exertsantidepressant effects either by enhancing left dor-solateral prefrontal cortex (DLPFC) excitability orby decreasing right DLPFC excitability, the au-thors studied 45 patients with unipolar recurrentmajor depressive disorder in a double-blind, ran-domized, parallel group, sham-controlled trial. Pa-tients were randomized to receive 1 Hz or 10 HzrTMS to the left DLPFC, 1 Hz to the rightDLPFC or sham TMS. Left 10 Hz and right 1 HzrTMS showed similar significant antidepressanteffects. Other parameters led to no significantantidepressant effectThis study was supported in part by grants from the Spanish Ministerio de Educacion y Cienca (DGICYT), the Milton Fund, the Stanley Vada NAMI Foundation, the National Alliance for Research in Schizophrenia and Depression, and NIMHMedicin

Two Better Than One? Potential Effects of Intraguild Predation on the Biological Control of Ceratitis capitata (Diptera: Tephritidae) by the Parasitoid Aganaspis daci (Hymenoptera: Figitidae) and the Predator Pseudoophonus rufipes (Coleoptera: Carabidae)

The use of more than one species to manage a single insect pest is a common practice among biological control programs. However, the beneficial effects of natural enemies are not always additive, which in many cases may be attributed to interspecific interactions such as intraguild predation (IGP). Herein, we investigated the potential IGP between two relevant natural enemies of the Medfly (Ceratitis capitata), the predator Pseudoophonus rufipes and the parasitoid Aganaspis daci, as well as the possible implications of this phenomenon in their efficiency as biocontrol agents. To this end, we assessed their functional responses and different demographic parameters when acting alone and together against C. capitata under laboratory conditions. Coexistence led to a switch in the functional response of both species, from type III to type II in A. daci and the opposite in P. rufipes. Regarding demographic parameters, coexistence resulted in higher parasitoidism and population reduction by A. daci only at low host densities, probably due to competition pressure. In the same circumstances, P. rufipes reduced its predatory activity, rejecting those larvae that were presumably parasitized and causing negligible IGP. At high Medfly densities, A. daci efficiency decreased, and the reduced encounter probability enhanced the predatory activity by P. rufipes. As a result of these trends, Medfly population reduction reached almost 100% at all densities, which suggests an additive effect of both natural enemies and recommends combined releases of these agents as a strategy for the control of the Medfly