Thermophysical properties of H2O and D2O ice Ih with contributions from proton disorder, quenching, relaxation, and extended defects: A model case for solids with quenching and relaxation.

Application of the coherent thermodynamic model [W. Holzapfel and S. Klotz, J. Chem. Phys. 155, 024506 (2021)] for H2O ice Ih to the more detailed data for D2O ice Ih provides better insight into the contributions from quenched proton disorder and offers a new basis for understanding the apparent differences between the data for thermal expansion measured with neutron diffraction on polycrystalline samples [A. Fortes, Acta Crystallogr., Sect. B: Struct. Sci., Cryst. Eng. Mater. 74, 196 (2018) and A. Fortes, Phys. Chem. Chem. Phys 21, 8264 (2019)] and macroscopic dilatation measurements on single crystals [D. Buckingham et al., Phys. Rev. Lett. 121, 185505 (2018)]. The comparison points to contributions from defects effecting the two techniques in different ways. The uncertainties in thermodynamic data due to the contributions from proton disorder and additional defects are compared with the "reference data" [R. Feistel and W. Wagner, J. Phys. Chem. Ref. Data 35, 1021 (2006)] for H2O ice Ih.

An update on the taxonomy and functional properties of the probiotic Enterococcus faecium SF68.

Enterococcus faecium SF68 (SF68) is a well-known probiotic with a long history of safe use. Recent changes in the taxonomy of enterococci have shown that a novel species, Enterococcus lactis, is closely related with E. faecium and occurs together with other enterococci in a phylogenetically well-defined E. faecium species group. The close phylogenetic relationship between the species E. faecium and E. lactis prompted a closer investigation into the taxonomic status of E. faecium SF68. Using phylogenomics and ANI, the taxonomic analysis in this study showed that probiotic E. faecium SF68, when compared to other E. faecium and E. lactis type and reference strains, could be re-classified as belonging to the species E. lactis. Further investigations into the functional properties of SF68 showed that it is potentially capable of bacteriocin production, as a bacteriocin gene cluster encoding the leaderless bacteriocin EntK1 together with putative Lactococcus lactis bacteriocins LsbA, and LsbB-like putative immunity peptide (LmrB) were found located in an operon on plasmid pF9. However, bacteriocin expression was not studied. Competitive exclusion experiments in co-culture over 7 days at 37 °C showed that the probiotic SF68 could inhibit the growth of specific E. faecium and Listeria monocytogenes strains, while showing little or no inhibitory activity towards an entero-invasive Escherichia coli and a Salmonella Typhimurium strain, respectively. In cell culture experiments with colon carcinoma HT29 cells, the probiotic SF68 was also able to strain-specifically inhibit adhesion and/or invasion of enterococcal and L. monocytogenes strains, while such adhesion and invasion inhibition effects were less pronounced for E. coli and Salmonella strains. This study therefore provides novel data on the taxonomy and functional properties of SF68, which can be reclassified as Enterococcus lactis SF68, thereby enhancing the understanding of its probiotic nature.

Role of gastrointestinal microbial populations, a terra incognita of the human body in the management of intestinal bowel disease and metabolic disorders.

Intestinal bowel disease (IBD) is a chronic immune-mediated clinical condition that affects the gastrointestinal tract and is mediated by an inflammatory response. Although it has been extensively studied, the multifactorial aetiology of this disorder makes it difficult to fully understand all the involved mechanisms in its development and therefore its treatment. In recent years, the fundamental role played by the human microbiota in the pathogenesis of IBD has been emphasised. Microbial imbalances in the gut bacterial communities and a lower species diversity in patients suffering from inflammatory gastrointestinal disorders compared to healthy individuals have been reported as principal factors in the development of IBD. These served to support scientific arguments for the use of probiotic microorganisms in alternative approaches for the prevention and treatment of IBD. In a homeostatic environment, the presence of bacteria (including probiotics) on the intestinal epithelial surface activates a cascade of processes by which immune responses inhibited and thereby commensal organisms maintained. At the same time these processes may support activities against specific pathogenic bacteria. In dysbiosis, these underlying mechanisms will serve to provoke a proinflammatory response, that, in combination with the use of antibiotics and the genetic predisposition of the host, will culminate in the development of IBD. In this review, we summarised the main causes of IBD, the physiological mechanisms involved and the related bacterial groups most frequently associated with these processes. The intention was to enable a better understanding of the interaction between the intestinal microbiota and the host, and to suggest possibilities by which this knowledge can be useful for the development of new therapeutic treatments.

Safety and beneficial properties of bacteriocinogenic Pediococcus acidilactici and Pediococcus pentosaceus isolated from silage.

The control of Listeria monocytogenes is a relevant goal for dairy products, a process that begins from the supply of feed and management of animals' health. In the present study, we evaluated the safety of two bacteriocinogenic Pediococcus strains and show that both can be considered as safe, based on their haemolytic activity, biogenic amine production and antibiotic resistance, all evaluated through phenotypical and biomolecular approaches. Both strains have shown potential as a producer of γ-aminobutiric acid (GABA) and carry an incomplete set of genes related to folate biosynthesis; both strains were able to adhere to Caco-2 cell lines with adhesion rates of 6·59% ± 3·73 and 0·84% ± 0·48. Laboratory prepared clover silage, inoculated with each bacteriocinogenic Pediococcus strain and contaminated with L. monocytogenes, proved the hypothesis for bioprotective effect of the tested strains, with the tested pathogen eliminated in the first 24 h of the experiment. These results indicate that evaluated strains can be potential beneficial candidates for application in silage production.

Bacteriocin production by Leuconostoc citreum ST110LD isolated from organic farm soil, a promising biopreservative.

AIMS: The objective of this study was to isolate a bacteriocin-producing strain and to characterize the expressed bacteriocin for the control of Listeria monocytogenes with aim of biopreservation application. METHODS AND RESULTS: Soil samples from a Korean organic farm were subjected to microbiological analysis for isolation of potential bacteriocinogenic LAB, based on a three-level approach, using L. monocytogenes ATCC 15313 as an indicator test micro-organism. From a total of 17 isolates with inhibitory potential, seven were confirmed to be bacteriocin producers. The selected isolates were differentiated based on their morphology, catalase reaction, sugar fermentation profile obtained by API50CHL and by RAPD-PCR generating two unique profiles. One of the isolates, ST110LD, a specific strong producer of anti-Listeria bacteriocins (12 800 AU ml-1 ) was identified as Leuconostoc citreum. The proteinaceous nature of the inhibitory compound produced by Leuc. citreum ST110LD was confirmed through treatment with pepsin and α-chymotrypsin. Bacteriocin activity was observed to be not affected by the presence of milk, NaCl, SDS, Tween 80 or glycerol. Bacteriocin ST110LD effectively inhibited the growth of exponentially growing L. monocytogenes ATCC 15313 during a 10-h incubation period in BHI at 37°C. In addition, this bacteriocin showed specific inhibition of only Listeria spp., but did not inhibit the growth of beneficial cultures included in the microbial test panel for assessment of the spectrum of activity. CONCLUSIONS: Leuconostoc citreum ST110LD was evaluated as safe bacterium strain, producing bacteriocin with high specificity against listerial and enterococcal species. Specificity of producer strain and expressed bacteriocin can be explored in biopreservation of different fermented food products or applied in biotherapy of antibiotic resistant listerial or enterococcal infections. SIGNIFICANCE AND IMPACT OF THE STUDY: To the best of our knowledge, this is the first report of bacteriocin produced by Leuc. citreum strain with highly specific antimicrobial activity against Listeria sp. and Enterococcus sp.

Broadband, millimeter-wave antireflection coatings for large-format, cryogenic aluminum oxide optics.

We present two prescriptions for broadband ($ {\sim} 77 - 252\;{\rm GHz} $), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large-format (700 mm diameter) planar and plano-convex elements, the other for densely packed arrays of quasi-optical elements-in our case, 5 mm diameter half-spheres (called "lenslets"). The coatings comprise three layers of commercially available, polytetrafluoroethylene-based, dielectric sheet material. The lenslet coating is molded to fit the 150 mm diameter arrays directly, while the large-diameter lenses are coated using a tiled approach. We review the fabrication processes for both prescriptions, then discuss laboratory measurements of their transmittance and reflectance. In addition, we present the inferred refractive indices and loss tangents for the coating materials and the aluminum oxide substrate. We find that at 150 GHz and 300 K the large-format coating sample achieves $ (97 \pm 2)\% $ transmittance, and the lenslet coating sample achieves $ (94 \pm 3)\% $ transmittance.

Enterococcus faecium SF68 as a model for efficacy and safety evaluation of pharmaceutical probiotics.

As normal inhabitants of diverse ecosystems, including the human gastrointestinal tract, the enterococci, and especially the two species Enterococcus faecalis and Enterococcus faecium, can be considered ubiquitous with regard to our natural environment. E. faecium has gained special importance thanks to beneficial strains marketed as probiotics, and because of its beneficial role in traditional fermented foods such as artisanal cheeses in some Southern European countries. Yet, following reports on the increasing association of some enterococcal strains with nosocomial infections such as endocarditis and bacteraemia, it became evident that strains from clinical origin are frequently highly resistant to 'last-defence-line' antibiotics such as the glycopeptide derivatives. For this reason enterococci have been classified in risk group 2 in the European Directive 93/88. With this paper it is intended to clarify the uncertain situation around the safety of the species E. faecium, also with referring to intra-species heterogeneity. In fact, well established scientific and surveillance data support the safety of some probiotic E. faecium strains for both human and animal applications. As a model, summarising yet extensive information is provided on the efficacy and safety of E. faecium SF68®, a pharmaceutical probiotic with a long history of safe use. We propose the approach presented in this review as a model for the evaluation of safety of probiotic strains of this species.

Measurement of the cosmic microwave background polarization lensing power spectrum with the POLARBEAR experiment.

Gravitational lensing due to the large-scale distribution of matter in the cosmos distorts the primordial cosmic microwave background (CMB) and thereby induces new, small-scale B-mode polarization. This signal carries detailed information about the distribution of all the gravitating matter between the observer and CMB last scattering surface. We report the first direct evidence for polarization lensing based on purely CMB information, from using the four-point correlations of even- and odd-parity E- and B-mode polarization mapped over ∼30 square degrees of the sky measured by the POLARBEAR experiment. These data were analyzed using a blind analysis framework and checked for spurious systematic contamination using null tests and simulations. Evidence for the signal of polarization lensing and lensing B modes is found at 4.2σ (stat+sys) significance. The amplitude of matter fluctuations is measured with a precision of 27%, and is found to be consistent with the Lambda cold dark matter cosmological model. This measurement demonstrates a new technique, capable of mapping all gravitating matter in the Universe, sensitive to the sum of neutrino masses, and essential for cleaning the lensing B-mode signal in searches for primordial gravitational waves.

Evidence for gravitational lensing of the cosmic microwave background polarization from cross-correlation with the cosmic infrared background.

We reconstruct the gravitational lensing convergence signal from cosmic microwave background (CMB) polarization data taken by the Polarbear experiment and cross-correlate it with cosmic infrared background maps from the Herschel satellite. From the cross spectra, we obtain evidence for gravitational lensing of the CMB polarization at a statistical significance of 4.0σ and indication of the presence of a lensing B-mode signal at a significance of 2.3σ. We demonstrate that our results are not biased by instrumental and astrophysical systematic errors by performing null tests, checks with simulated and real data, and analytical calculations. This measurement of polarization lensing, made via the robust cross-correlation channel, not only reinforces POLARBEAR auto-correlation measurements, but also represents one of the early steps towards establishing CMB polarization lensing as a powerful new probe of cosmology and astrophysics.

Detection of B-mode polarization in the cosmic microwave background with data from the South Pole Telescope.

Gravitational lensing of the cosmic microwave background generates a curl pattern in the observed polarization. This "B-mode" signal provides a measure of the projected mass distribution over the entire observable Universe and also acts as a contaminant for the measurement of primordial gravity-wave signals. In this Letter we present the first detection of gravitational lensing B modes, using first-season data from the polarization-sensitive receiver on the South Pole Telescope (SPTpol). We construct a template for the lensing B-mode signal by combining E-mode polarization measured by SPTpol with estimates of the lensing potential from a Herschel-SPIRE map of the cosmic infrared background. We compare this template to the B modes measured directly by SPTpol, finding a nonzero correlation at 7.7σ significance. The correlation has an amplitude and scale dependence consistent with theoretical expectations, is robust with respect to analysis choices, and constitutes the first measurement of a powerful cosmological observable.

Dusty starburst galaxies in the early Universe as revealed by gravitational lensing.

In the past decade, our understanding of galaxy evolution has been revolutionized by the discovery that luminous, dusty starburst galaxies were 1,000 times more abundant in the early Universe than at present. It has, however, been difficult to measure the complete redshift distribution of these objects, especially at the highest redshifts (z > 4). Here we report a redshift survey at a wavelength of three millimetres, targeting carbon monoxide line emission from the star-forming molecular gas in the direction of extraordinarily bright millimetre-wave-selected sources. High-resolution imaging demonstrates that these sources are strongly gravitationally lensed by foreground galaxies. We detect spectral lines in 23 out of 26 sources and multiple lines in 12 of those 23 sources, from which we obtain robust, unambiguous redshifts. At least 10 of the sources are found to lie at z > 4, indicating that the fraction of dusty starburst galaxies at high redshifts is greater than previously thought. Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation.

Frequency multiplexed superconducting quantum interference device readout of large bolometer arrays for cosmic microwave background measurements.

A technological milestone for experiments employing transition edge sensor bolometers operating at sub-Kelvin temperature is the deployment of detector arrays with 100s-1000s of bolometers. One key technology for such arrays is readout multiplexing: the ability to read out many sensors simultaneously on the same set of wires. This paper describes a frequency-domain multiplexed readout system which has been developed for and deployed on the APEX-SZ and South Pole Telescope millimeter wavelength receivers. In this system, the detector array is divided into modules of seven detectors, and each bolometer within the module is biased with a unique ∼MHz sinusoidal carrier such that the individual bolometer signals are well separated in frequency space. The currents from all bolometers in a module are summed together and pre-amplified with superconducting quantum interference devices operating at 4 K. Room temperature electronics demodulate the carriers to recover the bolometer signals, which are digitized separately and stored to disk. This readout system contributes little noise relative to the detectors themselves, is remarkably insensitive to unwanted microphonic excitations, and provides a technology pathway to multiplexing larger numbers of sensors.

A massive, cooling-flow-induced starburst in the core of a luminous cluster of galaxies.

In the cores of some clusters of galaxies the hot intracluster plasma is dense enough that it should cool radiatively in the cluster's lifetime, leading to continuous 'cooling flows' of gas sinking towards the cluster centre, yet no such cooling flow has been observed. The low observed star-formation rates and cool gas masses for these 'cool-core' clusters suggest that much of the cooling must be offset by feedback to prevent the formation of a runaway cooling flow. Here we report X-ray, optical and infrared observations of the galaxy cluster SPT-CLJ2344-4243 (ref. 11) at redshift z = 0.596. These observations reveal an exceptionally luminous (8.2 × 10(45) erg s(-1)) galaxy cluster that hosts an extremely strong cooling flow (around 3,820 solar masses a year). Further, the central galaxy in this cluster appears to be experiencing a massive starburst (formation of around 740 solar masses a year), which suggests that the feedback source responsible for preventing runaway cooling in nearby cool-core clusters may not yet be fully established in SPT-CLJ2344-4243. This large star-formation rate implies that a significant fraction of the stars in the central galaxy of this cluster may form through accretion of the intracluster medium, rather than (as is currently thought) assembling entirely via mergers.

Modulation of the murine microbiome with a concomitant anti-obesity effect by Lactobacillus rhamnosus GG and Lactobacillus sakei NR28.

The microbiota of the gastrointestinal tract (GIT) constitutes the major part of the total human microbiome and is considered to be an important regulator of human health and host metabolism. Numerous investigations in recent years have focused on the connection between the human microbiota and metabolic diseases such as obesity, type II diabetes and atherosclerosis. Yet, little is known about the impact of probiotic consumption on the GIT microbial population and the potential effect on chronic diseases. In this study, the modulation of the microbial community in the murine small intestine resulting from probiotic feeding was investigated and was found to be associated with an anti-obesity effect. Changes in the microbiota of the mouse faeces and small intestine were monitored using quantitative real-time PCR and by following the mRNA expression levels of various obesity-related biomarkers following probiotic feeding in a mouse model. Lactobacillus rhamnosus GG and Lactobacillus sakei NR28 (a putative probiotic strain isolated from kimchi) were administered at a daily level of approximately 1×10(8) viable bacteria per mouse (C57BL/6J mice) for up to three weeks. Feeding these strains resulted in a significant reduction of epididymal fat mass, as well as obesity-related biomarkers like acetyl-CoA carboxylase, fatty acid synthase, and stearoyl-CoA desaturase-1 in the liver. The total number and ratio of the microbial groups, i.e. Firmicutes, Bacteroidetes, Clostridium cluster I and XIVab, and Lactobacillus spp. were modulated in the small intestine, and the Firmicutes:Bacteroidetes ratio was decreased. In contrast, no noticeable effect of probiotic feeding could be detected on the faecal microbiota, neither quantitatively, nor with regard to the bacterial groups (Firmicutes, Bacteroidetes, Clostridium cluster I and XIVab, and Lactobacillus spp.) studied.

Invited article: millimeter-wave bolometer array receiver for the Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument.

The Atacama pathfinder experiment Sunyaev-Zel'dovich (APEX-SZ) instrument is a millimeter-wave cryogenic receiver designed to observe galaxy clusters via the Sunyaev-Zel'dovich effect from the 12 m APEX telescope on the Atacama plateau in Chile. The receiver contains a focal plane of 280 superconducting transition-edge sensor (TES) bolometers instrumented with a frequency-domain multiplexed readout system. The bolometers are cooled to 280 mK via a three-stage helium sorption refrigerator and a mechanical pulse-tube cooler. Three warm mirrors, two 4 K lenses, and a horn array couple the TES bolometers to the telescope. APEX-SZ observes in a single frequency band at 150 GHz with 1' angular resolution and a 22' field-of-view, all well suited for cluster mapping. The APEX-SZ receiver has played a key role in the introduction of several new technologies including TES bolometers, the frequency-domain multiplexed readout, and the use of a pulse-tube cooler with bolometers. As a result of these new technologies, the instrument has a higher instantaneous sensitivity and covers a larger field-of-view than earlier generations of Sunyaev-Zel'dovich instruments. The TES bolometers have a median sensitivity of 890 µK(CMB)√s (NEy of 3.5 × 10(-4) √s). We have also demonstrated upgraded detectors with improved sensitivity of 530 µK(CMB)√s (NEy of 2.2 × 10(-4) √s). Since its commissioning in April 2007, APEX-SZ has been used to map 48 clusters. We describe the design of the receiver and its performance when installed on the APEX telescope.

South Pole Telescope optics.

The South Pole Telescope is a 10 m diameter, wide-field, offset Gregorian telescope with a 966-pixel, millimeter-wave, bolometer array receiver. The telescope has an unusual optical system with a cold stop around the secondary. The design emphasizes low scattering and low background loading. All the optical components except the primary are cold, and the entire beam from prime focus to the detectors is surrounded by cold absorber.

Survival rate analysis of freeze-dried lactic acid bacteria using the arrhenius and z-value models.

The survival rate of five freeze-dried bacteria species, Lactobacillus plantarum, Lactobacillus pentosus, Weisella paramesenteroides, Leuconostoc mesenteroides, and Lactobacillus fermentum, was described in terms of reaction rate constants (D or k) and temperature sensitivity of rate constants (z or Ea). The freeze-dried strains were stored under vacuum at 55, 37, and 4 degrees C for 168 h, 17 days, and 2 months, respectively. D-values decreased and k increased with an increase of the storage temperature. Neither the z-value nor the inactivation energy (Ea) of the reaction was significantly different (P > 0.05) for all the strains, suggesting that thermal inactivation of the freeze-dried lactic acid bacteria may occur by the same mechanism. Therefore, it was possible to compare rate constants of survival for the freeze-dried strains studied.

Boza, a natural source of probiotic lactic acid bacteria.

AIMS: To evaluate the probiotic properties of strains isolated from boza, a traditional beverage produced from cereals. METHODS AND RESULTS: The strains survived low pH conditions (pH 3.0), grew well at pH 9.0 and were not inhibited by the presence of 0.3% (w/v) oxbile. Cytotoxicity levels of the bacteriocins, expressed as CC(50), ranged from 38 to 3776 microg ml(-1). Bacteriocin bacST284BZ revealed high activity (EC(50) = 735 microg ml(-1)) against herpes simplex virus type 1. Growth of Mycobacterium tuberculosis was 69% repressed after 5 days in the presence of bacST194BZ. Various levels of auto-cell aggregation and co-aggregation with Listeria innocua LMG 13568 were observed. Adhesion of the probiotic strains to HT-29 cells ranged from 18 to 22%. CONCLUSIONS: Boza is a rich source of probiotic lactic acid bacteria. All strains survived conditions simulating the gastrointestinal tract and produced bacteriocins active against a number of pathogens. Adherence to HT-29 and Caco-2 cells was within the range reported for Lactobacillus rhamnosus GG, a well-known probiotic. In addition, the high hydrophobicity readings recorded define the strains as good probiotics. SIGNIFICANCE AND IMPACT OF THE STUDY: Boza contains a number of different probiotic lactic acid bacteria and could be marketed as a functional food product.

Anti-listerial activity of bacteriocin-producing Lactobacillus curvatus CWBI-B28 and Lactobacillus sakei CWBI-B1365 on raw beef and poultry meat.

AIM: The study aimed to evaluate the effect of the bacteriocins produced by Lactobacillus sakei CWBI-B1365 and Lactobacillus curvatus CWBI-B28 on the growth and survival of Listeria monocytogenes in raw beef and poultry meat. METHODS AND RESULTS: The sakacin P and sakacin G structural genes were identified in Lact. curvatus CWBI-B28 and Lact. sakei CWBI-B1365 using PCR amplification, respectively. The effect of the two bacteriocinogenic strains either alone or together, and that of the nonbacteriocin-producing strain Lact. sakei LMG17302, on the growth of L. monocytogenes was evaluated in beef and poultry meat. In raw beef, the pathogenic bacteria were inhibited by the bacteriocinogenic strains. The bacteriocinogenic strains had no activity in raw chicken meat when inoculated separately, while they showed a clear anti-Listeria effect when applied together. CONCLUSION: Sakacin G producing Lact. sakei and sakacin P producing Lact. curvatus may be applied in raw beef to inhibit L. monocytogenes. In poultry meat, the inhibition of L. monocytogenes could only be achieved by a combined application of these bacteriocin-producing strains. SIGNIFICANCE AND IMPACT OF THE STUDY: In some meat products, the combined application of different class IIa bacteriocin producing lactic acid bacterium can enhance the anti-listerial activity.