Neuromodulatory inputs are known to strongly influence the intrinsic excitability of individual neurons and the networks in which the targets of modulation are found. It is therefore important to understand how nervous systems respond to altered neuromodulatory environments.

Each animal alive in the world is different from all other individuals, while sharing most attributes of form and function with others of the same species. Still other attributes are shared within a phylum, and still others are common to most eukaryotic organisms. All animals have mechanisms that modulate the strength of their synapses or alter the intrinsic excitability of component neurons. What animal-to-animal variability in behavior arises from differences in neuronal structure, ion channel expression, or connectivity, and what variability arises from neuromodulation of brain states? Conversely, can robust behavior be maintained despite variability in circuit components by the action of neuromodulatory inputs? These are fundamental issues relevant to all nervous systems that have been illuminated by many years of study of the small, rhythmic motor circuits found in the crustacean stomatogastric nervous system.

Hamood AW, Marder E. Consequences of acute and long-term removal of neuromodulatory input on the episodic gastric rhythm of the crab Cancer borealis. J Neurophysiol 114: 1677-1692. First published July 8, 2015 doi:10.1152/jn.00536.2015.-For decades, the episodic gastric rhythm of the crustacean stomatogastric nervous system (STNS) has served as an important model system for understanding the generation of rhythmic motor behaviors. Here we quantitatively describe many features of the gastric rhythm of the crab Cancer borealis under several conditions. First, we analyzed spontaneous gastric rhythms produced by freshly dissected preparations of the STNS, including the cycle frequency and phase relationships among gastric units. We find that phase is relatively conserved across frequency, similar to the pyloric rhythm. We also describe relationships between these two rhythms, including a significant gastric/ pyloric frequency correlation. We then performed continuous, dayslong extracellular recordings of gastric activity from preparations of the STNS in which neuromodulatory inputs to the stomatogastric ganglion were left intact and also from preparations in which these modulatory inputs were cut (decentralization). This allowed us to provide quantitative descriptions of variability and phase conservation within preparations across time. For intact preparations, gastric activity was more variable than pyloric activity but remained relatively stable across 4 -6 days, and many significant correlations were found between phase and frequency within animals. Decentralized preparations displayed fewer episodes of gastric activity, with altered phase relationships, lower frequencies, and reduced coordination both among gastric units and between the gastric and pyloric rhythms. Together, these results provide insight into the role of neuromodulation in episodic pattern generation and the extent of animal-to-animal variability in features of spontaneously occurring gastric rhythms.

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Most projects fail due to information overload. However, the project management information system (PMIS) and other technological support help the project managers (PM) make better decisions. This study looks at the issues of overloaded project information in Omani construction companies that the project managers must deal with. The study was based on quantitative data. The data is based on a survey through a structured questionnaire adopted from previous studies. The target population was the project managers (PMs) leading different construction companies in Oman, and about 296 PMs were approached. Two-stage sampling approach was adopted to collect the data and use SPSS software to analyse the data. The findings indicated that project managers can benefit from using a project management information system (PMIS), and project information overload had no adverse effects. The information system for project management favourably influences decisions. This research benefits project managers, especially those handling complex construction projects.   Multiple factors affect the decision-making process in construction companies; therefore, the research recommends exploring the contextual factors regarding the construction industry in Oman and assessing their impact on decision-making processes and project performance.

Figure 5. (A,B) Example lvn recordings from two intact preparations of the STNS showing highly similar pyloric rhythms. (C,D) Following decentralization, after 30 min these same two preparations show highly divergent responses to the perturbation, with dissimilar pyloric rhythms.Corrigendum

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