New ZZ Ceti stars from the LAMOST survey

The spectroscopic sky survey carried out by the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) provides the largest stellar spectra library in the world until now. A large number of new DA white dwarfs had been identified based on the LAMOST spectra. The effective temperature ($T_{\rm eff}$) and surface gravity ($\log g$) of most DA white dwarfs were determined and published in the catalogs, e.g. Zhao et al. (2013), Rebassa-Mansergas et al. (2015), Gentile Fusillo et al. (2015) and Guo et al. (2015). We selected ZZ Ceti candidates from the published catalogs by considering whether their $T_{\rm eff}$ are situated in the ZZ Ceti instability strip. The follow-up time-series photometric observations for the candidates were performed in 2015 and 2016. Four stars: LAMOST J004628.31+343319.90, LAMOST J062159.49+252335.9, LAMOST J010302.46+433756.2 and LAMOST J013033.90+273757.9 are finally confirmed to be new ZZ Ceti stars. They show dominant peaks with amplitudes rising above the 99.9% confidence level in the amplitude spectra. As LAMOST J004628.31+343319.90 has an estimated mass of $\sim$ 0.40 $M_{\odot}$ and LAMOST J013033.90+273757.9 has a mass of $\sim$ 0.45 $M_{\odot}$ derived from their $\log g$ values, these two stars are inferred to be potential helium-core white dwarfs.Comment: 15 pages, 8 figures, 3 tables, accepted for publication in Ap

Serum protein electrophoresis in healthy and injured southern white rhinoceros (<i>Ceratotherium simum simum</i>)

<div><p>Investigation of globulin fractions by serum protein electrophoresis (SPE) is the first step towards evaluation of the proteome in the southern white rhinoceros (<i>Ceratotherium simum simum</i>). Furthermore, identification of changes in globulins in animals with poaching and other injuries can guide discovery of potentially useful biomarkers of inflammation. The aim of this study was to develop reference intervals for agarose gel SPE in healthy white rhinoceros and to compare these serum protein electrophoresis results to those from animals with tissue trauma. Reference intervals for total serum protein and agarose gel electrophoretic albumin and globulin fractions were generated using serum samples from 49 healthy free-ranging adult white rhinoceros. A standardised gating system together with identification of specific proteins by mass spectrometry aided in fraction identification. Six globulin fractions were identified: α1a, α1b, α2, β1, β2 and γ. Reference intervals were generated for total serum protein (76–111 g/L), albumin (10–27 g/L) and globulin fractions (α1a: 1.6–3.2 g/L; α1b: 1.7–3.6 g/L; α2: 16.1–26.6 g/L; β1: 6.6–18.2 g/L; β2: 11.8–30.4 g/L; γ: 10.4–23.1 g/L; albumin: globulin ratio: 0.12–0.39). Results were compared to those from 30 animals with various degrees and chronicities of tissue trauma. Wounded animals had lower concentrations of total serum protein, albumin, total globulin, α and β1 globulins, lower percentages of α2 and β1 globulins, and higher percentages of β2 and γ globulins. These protein changes are similar to those seen in human patients with wounds rather than classic acute phase or chronic inflammatory responses.</p></div

Serum protein reference intervals for the white rhinoceros.

<p>Serum protein reference intervals for the white rhinoceros.</p

Estimates of imprecision and Rf values for different protein fractions in white rhinoceros serum on the Interlab Pretty electrophoresis platform.

<p>Estimates of imprecision and Rf values for different protein fractions in white rhinoceros serum on the Interlab Pretty electrophoresis platform.</p

Summarized signalment and clinical information for 30 white rhinoceros with tissue trauma.

<p>Summarized signalment and clinical information for 30 white rhinoceros with tissue trauma.</p

Comparison of results for total serum protein, albumin and globulin fractions for healthy and injured white rhinoceros.

<p>Comparison of results for total serum protein, albumin and globulin fractions for healthy and injured white rhinoceros.</p

Proteins identified in the candidate α1b and α2 bands, with their reported electrophoretic migration in other species, as previously reported [12–15, 28–30].

<p>Proteins identified in the candidate α1b and α2 bands, with their reported electrophoretic migration in other species, as previously reported [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0200347#pone.0200347.ref012" target="_blank">12</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0200347#pone.0200347.ref015" target="_blank">15</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0200347#pone.0200347.ref028" target="_blank">28</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0200347#pone.0200347.ref030" target="_blank">30</a>].</p

Study design and results for iTRAQ^® protocol.

<p>A—the iTRAQ^® reagent is designed as an isobaric stable tag consisting in a charged reporter group that retains charge (N,N-dimethylpiperazine), a peptide reactive group (N-hydoxy-succinimide) that is amide-linked to the N-terminus and the ε-amino side chains of all the peptides got from prior tryptic digestion, and a neutral balance portion (carbonyl) to maintain an overall mass of 305 kDa by the means of differential isotopic enrichment with ¹³C, ¹⁵N and ¹⁸O atoms. The selection of the reporter region in the low mass area enables keeping the additive mass to the fragments as negligible as possible in order to minimize any side effect during chromatographic separation and to avoid any interference with other fragment ions during mass spectrometry analysis, thus allowing for the highest degree of confidence; B—rabbit blood samples were pooled according to their clinical status. Some of them were represented in different groups (<i>e</i>.<i>g</i>. convalescent rabbits with past <i>E</i>. <i>cuniculi</i> disease but that currently underwent active inflammation due to bacteria), while other were rejected because clinical course was not clear enough. Overabundant proteins, like albumin and immunoglobulins, were removed through a commercial kit before mass spectrometry analysis. During this latter, the reporter-balance peptides remained intact, so that for one given common protein, the five samples had an identical <i>m/z</i>: the peptide fragments were equal, only the reporter ions were different. Indeed, the precursor ions and all the internal fragment ions, <i>i</i>.<i>e</i>., type b- and y-ions respectively, contain all five members of the tag set, but remain isobaric, <i>i</i>.<i>e</i>. <i>t</i>he five species have the same atomic mass but different arrangements. Thus, after collision in the mass spectrometry instrument, the five reporter group ions appeared as distinct masses ranging between <i>m/z</i> 113–117, while the remainder of the sequence-informative b- and—y ions remain isobaric and their individual current signal intensities were additive. The relative concentration of the peptides in every samples pool was then deduced from the relative signal intensities of the corresponding reporter ions; C—the hierarchical cluster diagram was constructed on the basis that, as they were considered as positive controls, non-<i>E</i>. <i>cuniculi</i> diseased rabbits with miscellaneous inflammatory processes (114-iTRAQ^® tag) were used as baseline. Data are visualized colorimetrically with heat plots, ‘red’ representing elevated gene expression, and ‘green’ decreased protein representation; D—the forest plot diagram shows expression levels for the 11 proteins that were found to be significantly overrepresented in <i>E</i>. <i>cuniculi</i> diseased rabbits with neurological signs (117-iTRAQ^® tag) in comparison with <i>E</i>. <i>cuniculi</i> diseased individuals with renal signs only (116-iTRAQ^® tag). Abbreviations: b-ion, precursor ion; C, Carbon; Da, Dalton; MS, Mass spectrometry; <i>m/z</i>, mass-to-charge ratio; O, Oxygen; N, azote; y-ion, internal ion.</p

Example of negative and positive Western blot (WB) patterns for extracted <i>Encephalitozoon cuniculi</i> proteins using goat anti-rabbit IgG conjugate.

<p>The identification of the proteins in the SDS-PAGE gel (right panel) corresponding to the bands of interest on the WB (left panel) are listed on the right. In brackets: the respective sensitivity and specificity for IgG and IgM detection for each WB band. The protein identified as spore wall and anchoring disk complex protein EnP1 at 17–19 kDa was actually a fragment of the one found in 40 kDa. Abbreviations: -, Negative; +, Positive; kDa, Kilodalton; WB, Western blot.</p

List of the microsporidian proteins which were located in regions of the Coomassie-blue SDS-PAGE gel that corresponded to the bands detected in Western blotting analysis using sera from the rabbits infected with <i>Encephalitozoon cuniculi</i>.

<p>List of the microsporidian proteins which were located in regions of the Coomassie-blue SDS-PAGE gel that corresponded to the bands detected in Western blotting analysis using sera from the rabbits infected with <i>Encephalitozoon cuniculi</i>.</p