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This paper studies two inverse eigenvalue problems for two kinds of acyclic matrices whose graphs are caterpillars. The spectral data of the first problem considers the minimal and maximal eigenvalues of all leading principal submatrices of the matrix. The second consists of an extremal eigenvalue of each leading principal submatrix and one eigenpair of the matrix. In the main results, we give sufficient conditions for the existence of such matrices, and their proofs provide algorithmic procedures for their construction. Finally, we present some numerical examples that illustrate the applicability of the solutions obtained. [ABSTRACT FROM AUTHOR]

Summary: Mechanisms underlying loss of consciousness following propofol administration remain incompletely understood. The objective of this study was to compare frontal lobe electroencephalography activity and brainstem reflexes during intravenous induction of general anaesthesia, in patients receiving a typical bolus dose (fast infusion) of propofol compared with a slower infusion rate. We sought to determine whether brainstem suppression ('bottom‐up') predominates over loss of cortical function ('top‐down'). Sixteen ASA physical status‐1 patients were randomly assigned to either a fast or slow propofol infusion group. Loss of consciousness and brainstem reflexes were assessed every 30 s by a neurologist blinded to treatment allocation. We performed a multitaper spectral analysis of all electroencephalography data obtained from each participant. Brainstem reflexes were present in all eight patients in the slow infusion group, while being absent in all patients in the fast infusion group, at the moment of loss of consciousness (p = 0.010). An increase in alpha band power was observed before loss of consciousness only in participants allocated to the slow infusion group. Alpha band power emerged several minutes after the loss of consciousness in participants allocated to the fast infusion group. Our results show a predominance of 'bottom‐up' mechanisms during fast infusion rates and 'top‐down' mechanisms during slow infusion rates. The underlying mechanisms by which propofol induces loss of consciousness are potentially influenced by the speed of infusion. [ABSTRACT FROM AUTHOR]

We consider two inverse eigenproblems for a real symmetric doubly arrowhead matrix An(q), which consist of constructing An(q) from two special kinds of spectra information. These problems were introduced in [11], where the principal results are sufficient conditions for both problems to have a real solution. In this paper, we improve such conditions, in the sense that one of the given conditions implies the rest. The results are constructive and generate one numerical procedure to construct the solution matrix An(q). [ABSTRACT FROM AUTHOR]

Dermal replacement materials bioactivated with cyanobacteria have shown promising potential for wound regeneration. To date, extraction of cyanobacteria RNA from seeded scaffolds has not been described. The aim of this study was to develop a method to isolate total RNA from bioactivated scaffolds and to propose a new approach in determining living bacteria based on real-time PCR. Transgenic Synechococcus sp. PCC 7002 (tSyn7002) were seeded in liquid cultures or scaffolds for dermal regeneration in vitro and in vivo for 7 days. RNA was extracted with a 260/280 ratio of ≥2. The small subunit of the 30S ribosome in prokaryotes (16S) and RNAse P protein (rnpA) were validated as reference transcripts for PCR analysis. Gene expression patterns differed in vitro and in vivo. Expression of 16S was significantly upregulated in scaffolds in vitro, as compared to liquid cultures, whilst rnpA expression was comparable. In vivo, both 16S and rnpA showed reduced expression compared to in vitro (16S: in vivo Ct value 13.21 ± 0.32, in vitro 12.44 ± 0.42; rnpA in vivo Ct value 19.87 ± 0.41, in vitro 17.75 ± 1.41). Overall, the results demonstrate rnpA and 16S expression after 7 days of implantation in vitro and in vivo, proving the presence of living bacteria embedded in scaffolds using qPCR., (© 2022 The Authors. Letters in Applied Microbiology published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology.)

The impact of pannexin-1 (Panx1) channels on synaptic transmission is poorly understood. Here, we show that selective block of Panx1 in single postsynaptic hippocampal CA1 neurons from male rat or mouse brain slices causes intermittent, seconds long increases in the frequency of sEPSC following Schaffer collateral stimulation. The increase in sEPSC frequency occurred without an effect on evoked neurotransmission. Consistent with a presynaptic origin of the augmented glutamate release, the increased sEPSC frequency was prevented by bath-applied EGTA-AM or TTX. Manipulation of a previously described metabotropic NMDAR pathway (i.e., by preventing ligand binding to NMDARs with competitive antagonists or blocking downstream Src kinase) also increased sEPSC frequency similar to that seen when Panx1 was blocked. This facilitated glutamate release was absent in transient receptor potential vanilloid 1 (TRPV1) KO mice and prevented by the TRPV1 antagonist, capsazepine, suggesting it required presynaptic TRPV1. We show presynaptic expression of TRPV1 by immunoelectron microscopy and link TRPV1 to Panx1 because Panx1 block increases tissue levels of the endovanilloid, anandamide. Together, these findings demonstrate an unexpected role for metabotropic NMDARs and postsynaptic Panx1 in suppression of facilitated glutamate neurotransmission. SIGNIFICANCE STATEMENT The postsynaptic ion and metabolite channel, pannexin-1, is regulated by metabotropic NMDAR signaling through Src kinase. This pathway suppresses facilitated release of presynaptic glutamate during synaptic activity by regulating tissue levels of the transient receptor potential vanilloid 1 agonist anandamide., (Copyright © 2020 the authors.)

Attention is a key cognitive phenomenon that is studied to understand cognitive disorders or even to estimate workloads to prevent accidents. Usually, it is studied using brain activity, even though it has many psychophysiological correlates. In the present study, we aim to evaluate if finger temperature, as a surrogate of peripheral vasoconstriction, can be used to obtain similar and complementary information to electroencephalography (EEG) brain activity measurements. To conduct this, 34 participants were recruited and submitted to performing four tasks-one as a baseline, and three attentional tasks. These three attentional tasks measured sustained attention, resilience to distractors, and attentional resources. During the tasks, the room, forehead, tympanic, and finger temperatures were measured. Furthermore, we included a 32-channel EEG recording. Our results showed a strong monotonic association between the finger temperature and the Alpha and Beta EEG spectral bands. When predicting attentional performance, the finger temperature was complementary to the EEG spectral measurements, through the prediction of aspects of attentional performance that had not been assessed by spectral EEG activity, or through the improvement of the model's fit. We also found that during the baseline task (non-goal-oriented task), the spectral EEG activity has an inverted correlation, as compared to a goal-oriented task. Our current results suggest that the psychophysiological assessment of attention is complementary to classic EEG approach, while also having the advantage of easy implementation of analysis tools in environments of reducing control (workplaces, student classrooms).