The Schwinger Variational Method

Variational methods have proven invaluable in theoretical physics and chemistry, both for bound state problems and for the study of collision phenomena. For collisional problems they can be grouped into two types: those based on the Schroedinger equation and those based on the Lippmann-Schwinger equation. The application of the Schwinger variational (SV) method to e-molecule collisions and photoionization has been reviewed previously. The present chapter discusses the implementation of the SV method as applied to e-molecule collisions

25th annual computational neuroscience meeting: CNS-2016

The same neuron may play different functional roles in the neural circuits to which it belongs. For example, neurons in the Tritonia pedal ganglia may participate in variable phases of the swim motor rhythms [1]. While such neuronal functional variability is likely to play a major role the delivery of the functionality of neural systems, it is difficult to study it in most nervous systems. We work on the pyloric rhythm network of the crustacean stomatogastric ganglion (STG) [2]. Typically network models of the STG treat neurons of the same functional type as a single model neuron (e.g. PD neurons), assuming the same conductance parameters for these neurons and implying their synchronous firing [3, 4]. However, simultaneous recording of PD neurons shows differences between the timings of spikes of these neurons. This may indicate functional variability of these neurons. Here we modelled separately the two PD neurons of the STG in a multi-neuron model of the pyloric network. Our neuron models comply with known correlations between conductance parameters of ionic currents. Our results reproduce the experimental finding of increasing spike time distance between spikes originating from the two model PD neurons during their synchronised burst phase. The PD neuron with the larger calcium conductance generates its spikes before the other PD neuron. Larger potassium conductance values in the follower neuron imply longer delays between spikes, see Fig. 17.Neuromodulators change the conductance parameters of neurons and maintain the ratios of these parameters [5]. Our results show that such changes may shift the individual contribution of two PD neurons to the PD-phase of the pyloric rhythm altering their functionality within this rhythm. Our work paves the way towards an accessible experimental and computational framework for the analysis of the mechanisms and impact of functional variability of neurons within the neural circuits to which they belong

High pressure processing for dark-firm-dry beef: effect on physical properties and oxidative deterioration during refrigerated storage

Objective Study on the application of high pressure processing (HPP) for dark-firm-dry (DFD) beef was conducted to observe whether HPP has any impact on physical properties and to evaluate oxidative deterioration during refrigerated storage under vacuum. Methods The longissimus lumborum muscles obtained from Friesian Holstein steers (33±0.5 months old) with 24-h postmortem pH higher than 6.0 were vacuum-packed and subjected to pressurization at 200, 400, and 600 MPa for 180 s at 15°C±2°C; the samples were then stored for 9 days at 4°C±1°C and compared with control (0.1 MPa). Results HPP increased meat pH by 0.1 to 0.2 units and the tenderness of cooked DFD beef significantly with no significant effects on meat texture profile. The stability of meat pH was well maintained during refrigerated storage under vacuum. No clear effects were found on the activity of catalase and superoxide dismutase, however, glutathione peroxidase activity was significantly reduced by high pressure. HPP and storage time resulted in aroma changes and the increasing amount of malondialdehyde and metmyoglobin relative composition. Conclusion Although the increasing amount of malondialdehyde content, metmyoglobin formation and aroma changes in HPP-treated samples could not be avoided, HPP at 200 MPa increased L* and a* values with less discoloration and oxidative deterioration during storage

Kiloniella antarctica sp. nov., isolated from a polynya of Amundsen Sea in Western Antarctic Sea

A taxonomic study was conducted on strain soj2014T, which was isolated from the surface water of a polynya in the Antarctic Sea. Comparative 16S rRNA gene sequence analysis showed that strain soj2014T belongs to the family Kiloniellaceae and is closely related to Kiloniella spongiae MEBiC09566T, ‘ Kiloniella litopenaei ’ P1-1T and Kiloniella laminariae LD81T (98.0 %, 97.8 % and 96.2 % 16S rRNA gene sequence similarity, respectively). The DNA–DNA hybridization values between strain soj2014T and closely related strains were below 28.6 %. The G+C content of the genomic DNA of strain soj2014T was 45.5 mol%. The predominant cellular fatty acids were summed feature 8 (composed of C18 : 1ω6c/C18  : 1ω7c, 57.0 %) and summed feature 3 (composed of C16 : 1ω6c/C16  : 1ω7c, 23.5 %). Strain soj2014T was Gram-stain-negative, slightly curved, spiral-shaped, and motile with a single polar flagellum. The strain grew at 0–30 °C (optimum, 25 °C), in 1.5–5.1 % (w/v) NaCl (optimum, 2.1–2.4 %) and at pH 5.5–9.5 (optimum, 7.5–8.0). It also had differential carbohydrate utilization traits and enzyme activities compared with closely related strains. Based on these phylogenetic, phenotypic and chemotaxonomic analyses, strain soj2014T represents a distinct species, separable from the reference strains, and is, therefore, proposed as a novel species, Kiloniella antarctica sp. nov. The type strain is soj2014T (=KCTC 42186T=JCM 30386T)

Reactivation of Hepatitis B Virus in HBsAg-Negative Patients with Hepatocellular Carcinoma - Fig 2

<p>A, Kaplan-Meier curves of HBV reactivation for the HCC and control groups. Patients with HCC undergoing TACE had significantly more frequent episodes of HBV reactivation during follow-up than controls without TACE, with estimated 12- and 24-month rates of 7.7% vs. 0% and 15.9% vs. 2.0%, respectively (<i>P</i> = 0.006, log-rank test). B, Comparison of HBV reactivation between the HCC and control groups. The risk of HBV reactivation was highest with combo + RT, followed by combo-TACE and mono-TACE, with estimated 24-month rates of 44.3%, 37.8%, and 6.2%, respectively (<i>P</i> = 0.001, log-rank test). C, Comparison of HBV reactivation according to prior CHB status. Patients with prior CHB had a significantly higher incidence of HBV reactivation than those without, with estimated 24-month rates of 53.7% and 7.5%, respectively (<i>P</i> < 0.001, log-rank test).</p

Patient enrollment and assessment.

<p>Patient enrollment and assessment.</p

Clinical features of 13 HBsAg-negative patients who developed HBV reactivation during the follow-up.

<p>HBsAg, hepatitis B surface antigen; HBV, hepatitis B virus; Pt, patient; M, male; F, female; TACE, transarterial chemoembolization; Mono, mono-drug TACE; Combo, combination-drug TACE; RT, radiotherapy; mo, months; UD, undetectable; No, number; Tx, treatment; ALT, alanine aminotransferase; SDH, subdural hemorrhage; PD, progressive disease; FU, follow-up.</p><p>Clinical features of 13 HBsAg-negative patients who developed HBV reactivation during the follow-up.</p