Multisensor hyperspectral imaging approach for the microchemical analysis of ultramarine blue pigments

This work presents a multisensor hyperspectral approach for the characterization of ultramarine blue, a valuable historical pigment, at the microscopic scale combining the information of four analytical techniques at the elemental and molecular levels. The hyperspectral images collected were combined in a single hypercube, where the pixels of the various spectral components are aligned on top of each other. Selected spectral descriptors have been defined to reduce data dimensionality before applying unsupervised chemometric data analysis approaches. Lazurite, responsible for the blue color of the pigment, was detected as the major mineral phase present in synthetic and good quality pigments. Impurities like pyrite were detected in lower quality samples, although the clear identification of other mineral phases with silicate basis was more difficult. There is no correlation between the spatial distribution of the bands arising in the Raman spectra of natural samples in the region 1200–1850 cm−1 and any of the transition metals or rare earth elements (REE). With this information, the previous hypothesis (based on bulk analysis) attributing these bands to luminescence emissions due to impurities of these elements must be revised. We propose the consideration of CO2 molecules trapped in the cages of the aluminosilicate structure of sodalite-type. Additionally, correlation between certain Raman features and the combined presence of Ca, P, and REE, in particular Nd, was detected for the lowest quality pigment. Our results highlight the usefulness of fusing chemical images obtained via different imaging techniques to obtain relevant information on chemical structure and properties.

mazEF Homologue Has a Minor Role in Staphylococcus epidermidis 1457 Virulence Potential

Staphylococcus epidermidis biofilm cells are characterized by increased antimicrobial tolerance and improved ability to evade host immune system defenses. These features are, in part, due to the presence of viable but non-culturable (VBNC) cells. A previous study identified genes potentially involved in VBNC cells formation in S. epidermidis biofilms, among which SERP1682/1681 raised special interest due to their putative role as a toxin–antitoxin system of the mazEF family. Herein, we constructed an S. epidermidis mutant lacking the mazEF genes homologues and determined their role in (i) VBNC state induction during biofilm formation, (ii) antimicrobial susceptibility, (iii) survival in human blood and plasma, and (iv) activation of immune cells. Our results revealed that mazEF homologue did not affect the proportion of VBNC cells in S. epidermidis 1457, refuting the previous hypothesis that mazEF homologue could be linked with the emergence of VBNC cells in S. epidermidis biofilms. Additionally, mazEF homologue did not seem to influence key virulence factors on this strain, since its deletion did not significantly affect the mutant biofilm formation capacity, antimicrobial tolerance or the response by immune cells. Surprisingly, our data suggest that mazEF does not behave as a toxin–antitoxin system in S. epidermidis strain 1457, since no decrease in the viability and culturability of bacteria was found when only the mazF toxin homologue was being expressed.

Enzymatic digestion of luminescent albumin-stabilized gold nanoclusters under anaerobic conditions: clues to the quenching mechanism

Many of the potential applications of albumin-stabilized gold nanoclusters (AuNC) arise from the sensitivity of their luminescence to the presence of various ions and albumin-degrading proteases. However, the underlying photophysics and the mechanisms responsible for protease-induced quenching of AuNC luminescence are not fully understood. Here, we study proteinase K-induced digestion of bovine serum albumin (BSA)-AuNC conjugate under aerobic and anaerobic conditions. To this end, we adapt a Co(II)-catalyzed sulfite-based protocol enabling effective in situ deoxidization without deactivation of the enzyme. In the absence of proteinase K, the anaerobic conditions facilitate luminescence of BSA-AuNC reflected by a moderate increase in the red luminescence intensity. However, in the presence of proteinase K, we have observed a steeper decrease of emission intensity irrespective of whether the digestion was carried out under aerobic or anaerobic conditions. In both cases, the diminishing fluorescence occurred in phase with shifting of the emission maximum to longer wavelengths. These results contradict the previous hypothesis that protease-induced quenching of BSA-AuNC luminescence is a consequence of enhanced diffusion of oxygen to bare AuNC. Instead, aggregation of unprotected AuNCs and separation of nanoclusters from albumin’s side chains involved in energy transfers and luminescence-promoting electron donors may underlie the observed sensitivity of BSA-AuNC to protease treatment. Our findings are discussed in the context of mechanisms of formation and photophysics of BSA-AuNC conjugates.

Social Parasite Ants in the Alps: a New Site of the Vulnerable Myrmica myrmicoxena and New Uppermost Altitudinal Limit for M. microrubra

We conducted a survey on the Alpine fauna of one of the largest Natural Park of the Italian Alps (Stelvio National Park) in the framework of a broad ecological monitoring of Alpine biodiversity. A two-years standardized sampling employing pitfall traps along a 1200 m altitudinal gradient led to the discovery of two interesting inquiline social parasite ants of the genus Myrmica: M. myrmicoxena Forel, 1895 and M. microrubra Seifert, 1993. Myrmica myrmicoxena, which is classified as Vulnerable according to the IUCN Red List, was so far known from only three sites across a narrow geographic range between Italy and Switzerland. Our data support the previous hypothesis over its ecology and host association. Myrmica microrubra is considered an incipient species of high evolutionary interest, sometimes regarded as an intraspecific form of M. rubra. While having a wide distribution in Europe, its presence in Italy was hitherto known only from a single site, and our record extends its altitudinal distribution limit in Europe upwards by about 600 m.

Investigating the Reward Cycle of Play in Pigs (Sus scrofa)

Observations of play in animals have been suggested as a promising indicator of positive emotions and thus of positive animal welfare. However, if play can follow the proposed reward cycle concept where animals estimate and value reward differently in different phases of the cycle (anticipation, consummation and post-consummation) is unclear. To investigate if a reward cycle for play exists in growing pigs, we carried out an exploratory study where pigs were tested when they were naïve to a reward cycle test (first occasion) against when they were accustomed to going through the test after having the access to an open play arena with objects. Forty undocked pigs were housed in a weaner stable with two castrated males and two females per pen. Within each litter, we randomly selected and tested one male and one female test pig, each being tested as naïve or accustomed to the testing environment. The first week the pigs (n = 20) were tested four times and regarded as naïve during the first day. After that they were regarded as accustomed, and were tested twice a week for 3 weeks. We observed the behavior of the tested pairs in three subsequent stages: (1) in a holding pen 3 min, (2) in a play arena 15 min, and (3) in their home pen 10 min. When accustomed, pigs showed more locomotor play, social interactions and standing, and a tendency of more orientation toward the play arena and exploring bars facing the play arena (i.e., reward-seeking behavior) in the holding pen than when they were naïve, suggesting an anticipation to enter the play arena. Performing high numbers of object play in all sessions, and for accustomed pigs more exploration and social interaction, but less locomotor play and walking in the play arena may suggest consumption of play and exploration. Finding more lying and sitting in accustomed pigs, but less standing and walking in the home pen is in line with the previous hypothesis of the post-consummatory behaviors. Our study showed mixed results for the existence of a reward cycle for play in pigs and generated questions for future research.

Racemate Resolution of Alanine and Leucine on Homochiral Quartz, and Its Alteration by Strong Radiation Damage

Homochiral proteins orchestrate biological functions throughout all domains of life, but the origin of the uniform l-stereochemistry of amino acids remains unknown. Here, we describe enantioselective adsorption experiments of racemic alanine and leucine onto homochiral d- and l-quartz as a possible mechanism for the abiotic emergence of biological homochirality. Substantial racemate resolution with enantiomeric excesses of up to 55% are demonstrated to potentially occur in interstitial pores, along grain boundaries or small fractures in local quartz-bearing environments. Our previous hypothesis on the enhanced enantioselectivity due to uranium-induced fission tracks could not be validated. Such capillary tubes in the near-surface structure of quartz have been proposed to increase the overall chromatographic separation of enantiomers, but no systematic positive correlation of accumulated radiation damage and enantioselective adsorption was observed in this study. In general, the natural l-quartz showed stronger enantioselective adsorption affinities than synthetic d-quartz without any significant trend in amino acid selectivity. Moreover, the l-enantiomer of both investigated amino acids alanine and leucine was preferably adsorbed regardless of the handedness of the enantiomorphic quartz sand. This lack of mirror symmetry breaking is probably due to the different crystal habitus of the synthetic z-bar of d-quartz and the natural mountain crystals of l-quartz used in our experiments.

Tracking the Evolutionary Trends Among Small-Size Fishes of the Genus Pyrrhulina (Characiforme, Lebiasinidae): New Insights From a Molecular Cytogenetic Perspective

Miniature fishes have always been a challenge for cytogenetic studies due to the difficulty in obtaining chromosomal preparations, making them virtually unexplored. An example of this scenario relies on members of the family Lebiasinidae which include miniature to medium-sized, poorly known species, until very recently. The present study is part of undergoing major cytogenetic advances seeking to elucidate the evolutionary history of lebiasinids. Aiming to examine the karyotype diversification more deeply in Pyrrhulina, here we combined classical and molecular cytogenetic analyses, including Giemsa staining, C-banding, repetitive DNA mapping, comparative genomic hybridization (CGH), and whole chromosome painting (WCP) to perform the first analyses in five Pyrrhulina species (Pyrrhulina aff. marilynae, Pyrrhulina sp., P. obermulleri, P. marilynae and Pyrrhulina cf. laeta). The diploid number (2n) ranged from 40 to 42 chromosomes among all analyzed species, but P. marilynae is strikingly differentiated by having 2n = 32 chromosomes and a karyotype composed of large meta/submetacentric chromosomes, whose plesiomorphic status is discussed. The distribution of microsatellites does not markedly differ among species, but the number and position of the rDNA sites underwent significant changes among them. Interspecific comparative genome hybridization (CGH) found a moderate divergence in the repetitive DNA content among the species’ genomes. Noteworthy, the WCP reinforced our previous hypothesis on the origin of the X1X2Y multiple sex chromosome system in P. semifasciata. In summary, our data suggest that the karyotype differentiation in Pyrrhulina has been driven by major structural rearrangements, accompanied by high dynamics of repetitive DNAs.

On the scarcity of redshifted OH and millimetre-band molecular absorption

ABSTRACT Despite much searching, redshifted decimetre- and millimetre-band absorption by molecular gas remains very rare, limited to just six systems at zabs ≳ 0.05. Detection of these transitions can yield precise diagnostics of the conditions of the star-forming gas in the earlier Universe, the hydroxyl (OH) radical being of particular interest as in the λ = 18 cm ground state there are four different transitions located close to neutral hydrogen 21- cm and thus detectable with the Square Kilometre Array and its pathfinders. The four transitions of OH have very different dependences on the fundamental constants, thus having much potential in testing for any evolution in these over large look-back times. By collating the photometry in a uniform manner, we confirm our previous hypothesis that the normalized OH absorption strength is correlated with the optical–near-infrared red colour of the sightline. Applying this to the published searches, we find that all, but one (J0414+054), have simply not been searched sufficiently deeply. We suggest that this is due to the standard selection of sources with reliable optical redshifts introducing a bias against those with enough dust with which to shield the molecular gas. For the single source searched to sufficient depth, we have reason to suspect that the high degree of reddening arises from another system along the sightline, thus not being inconsistent with our hypothesis. We also show that the same optical redshift bias can account for the scarcity of millimetre-band absorption.

Levels of serum IL6, TNF-α and sLAG3 are changed and correlated with clinical characteristics in Parkinson’s disease patients: A case-control study

Objective: An increasing body of studies have proved that inflammation plays a crucial role in Parkinson’s disease (PD) pathogenesis. IL-6, TNF-α and sLAG3 are associated with immune disorder. This study aimed to examine the expression of serum IL-6, TNF-α and sLAG3 in PD patients from China. Methods: Forty six PD patients and 42 age and gender-matched healthy controls (HC) were recruited. clinical data, disease assessment scale and serum IL-6, TNF-α and sLAG3 were assessed in PD patients. The levels of inflammatory factors were determined by enzyme-linked immunosorbent assay (ELISA). Results: The levels of serum IL-6 and TNF-α were significantly higher in PD patients compared to HC. Serum IL-6 and TNF-α were independent risk factors for PD. The levels of serum sLAG3 and TNF-α were higher in female patients than those of male patients. Significant positive correlation was found between serum TNF-α and H-Y, UPDRS III and HAMA in PD patients. Serum sLAG3 positively correlated with HAMA. Conclusion: Changes in serum inflammatory factors were observed in PD patients, which were correlated with the clinical characteristics. The study supports the previous hypothesis that inflammation is involved in the pathogenesis of PD.

Some Infections May Be Endogenous

This paper advances a previous hypothesis “Human body may produces bacteria”, and proposes that some infections may be endogenous. It has been demonstrated that the Christensenellaceae, a family in the phylum Firmicutes, is heritable suggesting that human genetic material and gut bacterial material are related and human cells may generate some gut microbes It has also been shown that the fetus is exposed to bacteria prior to birth -without any evidence that they are contaminants or acquired from the environment -suggesting a possible endogenous origin of bacteria in breast milk, meconium, placenta , umbilical cord blood and amniotic fluid. Malassezia yeasts are not contagious, not culturable from the environment, cannot colonize human skin by inoculation without occlusion and neonate skin is free of Malassezia but is colonized in the first month of life suggesting that they may be endogenous. Human stem cells seem to be the most likely candidates to produce microbes: This is because they differentiate to epithelial cells and cancer cells and contain the essentials to transform to microorganisms. Future experimental studies are necessary to validate this hypothesis which may offer a new paradigm to combat opportunistic infections of possible endogenous origin.