Health Care Workers at Risk

Health-care workers are at extreme risk not only of psychological but somatic disorders as well. Present paper - while presenting the outline of the poor situation of physicians and health-care professionals - strives to enumerate circumstantial factors that induce the probability of negative physical and biological consequences as well as occurrence and extent of burnout. It also aspires to cite all those features that can help diminish these negative outcomes.

Pattern generating role for motoneurons in a rythmically active neuronal network

The role of motoneurons in central motor pattern generation was investigated in the feeding system of the pond snail Lymnaea stagnalis, an important invertebrate model of behavioral rhythm generation. The neuronal network responsible for the three-phase feeding motor program (fictive feeding) has been characterized extensively and divided into populations of central pattern generator (CPG) interneurons, modulatory interneurons, and motoneurons. A previous model of the feeding system considered that the motoneurons were passive followers of CPG interneuronal activity. Here we present new, detailed physiological evidence that motoneurons that innervate the musculature of the feeding apparatus have significant electrotonic motoneuron¿interneuron connections, mainly confined to cells active in the same phase of the feeding cycle (protraction, rasp, or swallow). This suggested that the motoneurons participate in rhythm generation. This was assessed by manipulating firing activity in the motoneurons during maintained fictive feeding rhythms. Experiments showed that motoneurons contribute to the maintenance and phase setting of the feeding rhythm and provide an efficient system for phase-locking muscle activity with central neural activity. These data indicate that the distinction between motoneurons and interneurons in a complex CNS network like that involved in snail feeding is no longer justified and that both cell types are important in motor pattern generation. This is a distributed type of organization likely to be a general characteristic of CNS circuitries that produce rhythmic motor behavior

Multiple types of control by identified interneurons in a sensory-activated rhythmic motor pattern.

Modulatory interneurons that can drive central pattern generators (CPGs) are considered as good candidates for decision-making roles in rhythmic behaviors. Although the mechanisms by which such neurons activate their target CPGs are known in detail in many systems, their role in the sensory activation of CPG-driven behaviors is poorly understood. In the feeding system of the mollusc Lymnaea, one of the best-studied rhythmical networks, intracellular stimulation of either of two types of neuron, the cerebral ventral 1a (CV1a) and the slow oscillator (SO) cells, leads to robust CPG-driven fictive feeding patterns, suggesting that they might make an important contribution to natural food-activated behavior. In this paper we investigated this contribution using a lip-CNS preparation in which feeding was elicited with a natural chemostimulant rather than intracellular stimulation. We found that despite their CPG-driving capabilities, neither CV1a nor SO were involved in the initial activation of sucrose-evoked fictive feeding, whereas a CPG interneuron, N1M, was active first in almost all preparations. Instead, the two interneurons play important and distinct roles in determining the characteristics of the rhythmic motor output; CV1a by modulating motoneuron burst duration and SO by setting the frequency of the ongoing rhythm. This is an example of a distributed system in which (1) interneurons that drive similar motor patterns when activated artificially contribute differently to the shaping of the motor output when it is evoked by the relevant sensory input, and (2) a CPG rather than a modulatory interneuron type plays the most critical role in initiation of sensory-evoked rhythmic activity

The effective elastic thickness of the India Plate from receiver function imaging, gravity anomalies and thermomechanical modelling

The range and the meaning of the effective elastic thickness (EET) in continental areas have been subject to controversy over the last two decades. Here we take advantage of the new data set from the Hi-CLIMB seismological experiment to re-estimate the EET of the India Plate along a south-north profile extending from the Ganges basin to central Tibet. Receiver functions give a high-resolution image of the base of the foreland basin at similar to 5 km depth and constrain the crustal thickness, which increases northwards from similar to 35 km beneath the indo-gangetic plain to similar to 70 km in southern Tibet. Together with available data sets including seismic profiles, seismological images from both INDEPTH and HIMNT experiments, deep well measurements and Bouguer anomaly profiles, we interpret this new image with 2-D thermomechanical modelling solutions, using different type of crustal and mantle rheologies. We find that (1) the EET of the India Plate decreases northwards from 60-80 to 20-30 km as it is flexed down beneath Himalaya and Tibet, due to thermal and flexural weakening; (2) the only resistant layer of the India Plate beneath southern Tibet is the upper mantle, which serves as a support for the topographic load and (3) the most abrupt drop in the EET, located around 200 km south of the MFT, is associated with a gradual decoupling between the crust and the mantle. We show that our geometrical constraints do not allow to determine if the upper and lower crust are coupled or not. Our results clearly reveal that a rheology with a weak mantle is unable to explain the geometry of the lithosphere in this region, and they are in favour of a rheology in which the mantle is strong

Defense mechanisms of empathetic players in the spatial ultimatum game

Experiments on the ultimatum game have revealed that humans are remarkably fond of fair play. When asked to share an amount of money, unfair offers are rare and their acceptance rate small. While empathy and spatiality may lead to the evolution of fairness, thus far considered continuous strategies have precluded the observation of solutions that would be driven by pattern formation. Here we introduce a spatial ultimatum game with discrete strategies, and we show that this simple alteration opens the gate to fascinatingly rich dynamical behavior. Besides mixed stationary states, we report the occurrence of traveling waves and cyclic dominance, where one strategy in the cycle can be an alliance of two strategies. The highly webbed phase diagram, entailing continuous and discontinuous phase transitions, reveals hidden complexity in the pursuit of human fair play.Comment: 4 two-column pages, 5 figures; accepted for publication in Physical Review Letter

Critical time window for NO-cGMP-dependent long-term memory formation after one-trial appetitive conditioning

The nitric oxide (NO)-cGMP signaling pathway is implicated in an increasing number of experimental models of plasticity. Here, in a behavioral analysis using one-trial appetitive associative conditioning, we show that there is an obligatory requirement for this pathway in the formation of long-term memory (LTM). Moreover, we demonstrate that this requirement lasts for a critical period of ~5 hr after training. Specifically, we trained intact specimens of the snail Lymnaea stagnalis in a single conditioning trial using a conditioned stimulus, amyl-acetate, paired with a salient unconditioned stimulus, sucrose, for feeding. Long-term associative memory induced by a single associative trial was demonstrated at 24 hr and shown to last at least 14 d after training. Tests for LTM and its dependence on NO were performed routinely 24 hr after training. The critical period when NO was needed for memory formation was established by transiently depleting it from the animals at a series of time points after training by the injection of the NO-scavenger 2-phenyl-4,4,5,5-tetramethyl-imidazoline-1-oxyl 3-oxide (PTIO).By blocking the activity of NO synthase and soluble guanylyl cyclase enzymes after training, we provided further evidence that LTM formation depends on an intact NO-cGMP pathway. An electrophysiological correlate of LTM was also blocked by PTIO, showing that the dependence of LTM on NO is amenable to analysis at the cellular level in vitro. This represents the first demonstration that associative memory formation after single-trial appetitive classical conditioning is dependent on an intact NO-cGMP signaling pathway

Evolutionary prisoner's dilemma game on hierarchical lattices

An evolutionary prisoner's dilemma (PD) game is studied with players located on a hierarchical structure of layered square lattices. The players can follow two strategies [D (defector) and C (cooperator)] and their income comes from PD games with the ``neighbors.'' The adoption of one of the neighboring strategies is allowed with a probability dependent on the payoff difference. Monte Carlo simulations are performed to study how the measure of cooperation is affected by the number of hierarchical levels (Q) and by the temptation to defect. According to the simulations the highest frequency of cooperation can be observed at the top level if the number of hierarchical levels is low (Q<4). For larger Q, however, the highest frequency of cooperators occurs in the middle layers. The four-level hierarchical structure provides the highest average (total) income for the whole community.Comment: appendix adde

Evolutionary Prisoner's Dilemma game on the Newman-Watts networks

Maintenance of cooperation was studied for a two-strategy evolutionary Prisoner's Dilemma game where the players are located on a one-dimensional chain and their payoff comes from games with the nearest and next-nearest neighbor interactions. The applied host geometry makes possible to study the impacts of two conflicting topological features. The evolutionary rule involves some noise affecting the strategy adoptions between the interacting players. Using Monte Carlo simulations and the extended versions of dynamical mean-field theory we determined the phase diagram as a function of noise level and a payoff parameter. The peculiar feature of the diagram is changed significantly when the connectivity structure is extended by extra links as suggested by Newman and Watts.Comment: 4 figure