Lacerta kulzeri – filogenetički odnosi indicirani DNA sekvencijama

In order to resolve the relationships of Lacerta kulzeri, parts of mitochondrial genes for 12S rRNA and 16S rRNA of samples of the following species were sequenced: Gallotia stehlini (as an outgroup), Lacerta trilineata, L. cappadocica, L. fraasii, L. danfordi, L. rudis, Podarcis peloponnesiaca, as well as representatives of different populations of L. laevis and L. kulzeri. Sequence analysis clearly shows a close relation between L. laevis and L. kulzeri and no close relation of these species to any other representative of the lizards examined. The other species also show themselves to be representatives of very distinct lacertid groups. The resulting sequence differences within L. kulzeri and L. laevis, respectively, are very high in relation to those between the two species, and they are higher than one would expect for species with small areas.Da bi se razriješili odnosi Lacerta kulzeri, sekvencionirani su dijelovi mitohondrijskih gena za 12S rRNA i 16S rRNA uzoraka sljedećih vrsta: Gallotia stehlini (kao outgroup), Lacerta trilineata, L. cappadocica, L. fraasii, L. danfordi, L. rudis, Podarcis peloponnesiaca, kao i predstavnici različitih populacija L. laevis i L. kulzeri. Analiza sekvenci jasno pokazuje blisku vezu L. laevis i L. kulzeri, a nikakvu blisku vezu tih vrsta s ostalim ispitanim vrstama guštera. Ostale vrste također su se pokazale kao predstavnici vrlo različitih lacertidnih grupa. Konačne razlike u sekvencijama unutar L. kulzeri, odnosno, L. laevis su vrlo visoke u odnosu na one između dviju vrsta, i više su nego što bi se očekivalo za vrste s malim arealima

Raspodjela ekoloških niša između sedam simpatričkih lacertidnih gušterica u Peloponeškom gorju

All seven lacertid species recorded in the Peloponnese can be found in a very small area in the Arcadian highlands on the Peloponnese peninsula. Only one example of such unique diversity in such a small area has been described in the Mediterranean region before. This density requires the occupation of different restricted ecological and ethological niches by all seven species and therefore the habitats have to be diverse. Niche segregation, ecological demands and the ethological differences between the species are discussed in relation to this habitat diversity.Svih sedam lacertidnih vrsta zabilježenih za Peloponez mogu se naći na vrlo malom području u Arkadijskom gorju na poluotoku Peloponezu. Dosad je na području Sredozemlja poznat samo jedan primjer takve jedinstvene raznolikosti na tako malom prostoru. Takva gustoća zahtijeva zauzeće različitih ograničenih ekoloških i etoloških niša sa strane svih sedam vrsta i zbog toga staništa moraju biti raznolika. U radu se raspravlja o toj podijeljenosti niša, kao i o ekološkim zahtjevima i etološkim razlikama među vrstama, u odnosu na raznolikost staništa

Fish oil-containing lipid emulsions in patients with sepsis

Lipid emulsions based on soybean oil have been an integral part of parenteral nutrition supplying n-6 fatty acids, with possible negative effects in critically ill patients. Newer lipid emulsions supply less n-6 fatty acids. In addition, fish oil-based lipids may be included in the lipid component of parenteral nutrition. While clinical benefits of lipid emulsions with a reduced fraction in n-6 lipids and the addition of fish oil have been described in postoperative patients, data are less clear in critically ill or septic patients. Recent data suggest that beneficial effects may be achieved when used early but clearly more data are needed to come to a definitive conclusion. The present commentary will highlight current data in critically ill and septic patients and the use of fish oil as a part of parenteral nutrition

A kinematic study of central compact objects and their host supernova remnants

Context. Central compact objects (CCOs) are a peculiar class of neutron stars, primarily encountered close to the center of young supernova remnants (SNRs) and characterized by thermal X-ray emission. Aims. Our goal is to perform a systematic study of the proper motion of all known CCOs with appropriate data available. In addition, we aim to measure the expansion of three SNRs within our sample to obtain a direct handle on their kinematics and age. Methods. We analyze multiple archival Chandra data sets, consisting of HRC and ACIS observations separated by temporal baselines between 8 and 15 years. In order to correct for systematic astrometric uncertainties, we establish a reference frame using X-ray detected sources in Gaia DR2, to provide accurate proper motion estimates for our target CCOs. Complementarily, we use our coaligned data sets to trace the expansion of three SNRs by directly measuring the spatial offset of various filaments and ejecta clumps between different epochs. Results. In total, we present new proper motion measurements for six CCOs, among which we do not find any indication of a hypervelocity object. We tentatively identify direct signatures of expansion for the SNRs G15.9+0.2 and Kes 79, at estimated significance of $2.5\sigma$ and $2\sigma$, respectively. Moreover, we confirm recent results by Borkowski et al., measuring the rapid expansion of G350.1$-$0.3 at almost $6000\,{\rm km\,s^{-1}}$, which places its maximal age at $600-700$ years. The observed expansion, combined with the rather small proper motion of its CCO, implies the need for a very inhomogeneous circumstellar medium to explain the highly asymmetric appearance of the SNR. Finally, for the SNR RX J1713.7$-$3946, we combine previously published expansion measurements with our measurement of the CCO's proper motion to obtain a constraining upper limit of $1700$ years on the system's age.Comment: 22+8 pages, 16+3 figures. Accepted for publication in Astronomy & Astrophysic

Phylogeny of the nematode genus Pristionchus and implications for biodiversity, biogeography and the evolution of hermaphroditism

<p>Abstract</p> <p>Background</p> <p>The nematode <it>Pristionchus pacificus </it>has originally been developed as a satellite organism for comparison to <it>Caenorhabditis elegans</it>. A 10X coverage of the whole genome of <it>P. pacificus </it>is available, making <it>P. pacificus </it>the first non-<it>Caenorhabditis </it>nematode with a fully sequenced genome. The macroevolutionary comparison between <it>P. pacificus </it>and <it>C. elegans </it>has been complemented by microevolutionary studies of closely related strains and species within the genus <it>Pristionchus</it>. In addition, new understanding of the biology of <it>Pristionchus </it>from field studies, demonstrating a close association with various scarab beetles and the Colorado potato beetle, supports consideration of this nematode in studies of ecosystems. In the course of field studies on four continents more than 1,200 isolates were established from 15,000 beetle specimens representing 18 <it>Pristionchus </it>species. Two remarkable features of the <it>Pristionchus </it>– beetle association are the high species specificity of the interaction and the interception of the beetle's sex communication system for host recognition by the nematodes, as suggested by chemotaxis studies. Evolutionary interpretations of differences in developmental, behavioral and ecological patterns require a phylogenetic framework of the genus <it>Pristionchus</it>.</p> <p>Results</p> <p>Here, we provide a robust phylogeny of all 18 available <it>Pristionchus </it>species based on a set of 27 ribosomal protein genes encompassing a total of 10,971 bp. The phylogenetic tree provides evidence for North American and European clades, which are embedded in a deeper clade that includes Asian species. It also indicates putative invasion events. Of the 18 <it>Pristionchus </it>species, 13 are gonochoristic and five are hermaphroditic. The phylogeny indicates that all hermaphroditic species have arisen independently within the genus <it>Pristionchus</it>.</p> <p>Conclusion</p> <p>Combined ribosomal protein cDNA data can provide the basis for reconstruction of a robust phylogenetic framework for microevolutionary and biogeographic analyses. An additional major implication of our studies is the use of <it>Pristionchus </it>for nematode biodiversity assessments. While some species are represented by more than 100 isolates, others were found less than four times. Such patterns were observed on all continents and in all phylogenetic clades indicating that species asymmetry is a widespread phenomenon, which can now be further investigated by molecular tools.</p

Sex, bugs and Haldane's rule: the nematode genus Pristionchus in the United States

BACKGROUND: The nematode Pristionchus pacificus has been developed as a satellite organism in evolutionary developmental biology for comparison to Caenorhabditis elegans. Comparative studies have revealed major differences in the regulation of developmental processes between P. pacificus and C. elegans. To place evolutionary developmental biology and the observed developmental differences between species in a comprehensive evolutionary context, such studies have to be complemented with ecological aspects. Knowledge about the ecology of the organism in question might indicate specific environmental conditions that can result in developmental adaptations and could account for species differences in development. To this end, we have started to investigate the ecology of Pristionchus nematodes. In recent field studies in Western Europe we found six Pristionchus species that are closely associated with scarab beetles and the Colorado potato beetle. This Pristionchus – beetle association provides the unique opportunity to combine research in evolutionary developmental biology with ecology. However, it remains unknown how general these findings from Europe are on a global scale. RESULTS: Here, we describe the Pristionchus species associated with scarab and Colorado potato beetles in the Eastern United States and show striking transatlantic differences and unexpected evolutionary and ecological patterns. Twohundredeighty of 285 (98%) isolates from American scarab beetles belong to five Pristionchus species, all of which are different from the European species. We describe four of them as novel Pristionchus species. The five American Pristionchus species fall into a single phylogenetic clade and have a male-female (gonochoristic) mode of reproduction, whereas the majority of European isolates are hermaphroditic. Crosses between the two most closely related species, P. aerivorus and P. pseudaerivorus n. sp., follow Haldane's rule in that heterogametic F1 males are inviable. We observed P. aerivorus and P. pseudaerivorus n. sp. coexisting on the same scarab beetle and obtained two cases of F1 hybrids from wild beetles. Finally, the Colorado potato beetle is associated with the same nematode, P. uniformis in the United States and Europe. Given the introduction of the Colorado potato beetle to Europe in 1877, our results suggest that P. uniformis was introduced together with its beetle vector. CONCLUSION: Taken together, the Pristionchus – beetle association provides a powerful tool for studying biodiversity, biogeography, speciation and species invasion on a global scale

Molecular phylogeny of beetle associated diplogastrid nematodes suggests host switching rather than nematode-beetle coevolution

<p>Abstract</p> <p>Background</p> <p>Nematodes are putatively the most species-rich animal phylum. They have various life styles and occur in a variety of habitats, ranging from free-living nematodes in aquatic or terrestrial environments to parasites of animals and plants. The rhabditid nematode <it>Caenorhabditis elegans </it>is one of the most important model organisms in modern biology. <it>Pristionchus pacificus </it>of the family of the Diplogastridae has been developed as a satellite model for comparison to <it>C. elegans</it>. The Diplogastridae, a monophyletic clade within the rhabditid nematodes, are frequently associated with beetles. How this beetle-association evolved and whether beetle-nematode coevolution occurred is still elusive. As a prerequisite to answering this question a robust phylogeny of beetle-associated Diplogastridae is needed.</p> <p>Results</p> <p>Sequences for the nuclear small subunit ribosomal RNA and for 12 ribosomal protein encoding nucleotide sequences were collected for 14 diplogastrid taxa yielding a dataset of 5996 bp of concatenated aligned sequences. A molecular phylogeny of beetle-associated diplogastrid nematodes was established by various algorithms. Robust subclades could be demonstrated embedded in a phylogenetic tree topology with short internal branches, indicating rapid ancestral divergences. Comparison of the diplogastrid phylogeny to a comprehensive beetle phylogeny revealed no major congruence and thus no evidence for a long-term coevolution.</p> <p>Conclusion</p> <p>Reconstruction of the phylogenetic history of beetle-associated Diplogastridae yields four distinct subclades, whose deep phylogenetic divergence, as indicated by short internal branch lengths, shows evidence for evolution by successions of ancient rapid radiation events. The stem species of the Diplogastridae existed at the same time period when the major radiations of the beetles occurred. Comparison of nematode and beetle phylogenies provides, however, no evidence for long-term coevolution of diplogastrid nematodes and their beetle hosts. Instead, frequent host switching is observed. The molecular phylogeny of the Diplogastridae provides a framework for further examinations of the evolution of these associations, for the study of interactions within the ecosystems, and for investigations of diplogastrid genome evolution.</p

High Dual Expression of the Biomarkers CD44v6/α2β1 and CD44v6/PD-L1 Indicate Early Recurrence after Colorectal Hepatic Metastasectomy

Considering the biology of CRC, distant metastases might support the identification of high-risk patients for early recurrence and targeted therapy. Expression of a panel of druggable, metastasis-related biomarkers was immunohistochemically analyzed in 53 liver (LM) and 15 lung metastases (LuM) and correlated with survival. Differential expression between LM and LuM was observed for the growth factor receptors IGF1R (LuM 92.3% vs. LM 75.8%, p = 0.013), EGFR (LuM 68% vs. LM 41.5%, p = 0.004), the cell adhesion molecules CD44v6 (LuM 55.7% vs. LM 34.9%, p = 0.019) and α2β1 (LuM 88.3% vs. LM 58.5%, p = 0.001) and the check point molecule PD-L1 (LuM 6.1% vs. LM 3.3%, p = 0.005). Contrary, expression of HGFR, Hsp90, Muc1, Her2/neu, ERα and PR was comparable in LuM and LM. In the LM cohort (n = 52), a high CD44v6 expression was identified as an independent factor of poor prognosis (PFS: HR 2.37, 95% CI 1.18–4.78, p = 0.016). High co-expression of CD44v6/α2β1 (HR 4.14, 95% CI 1.65–10.38, p = 0.002) and CD44v6/PD-L1 (HR 2.88, 95% CI 1.21–6.85, p = 0.017) indicated early recurrence after hepatectomy, in a substantial number of patients (CD44v6/α2β1: 11 (21.15%) patients; CD44v6/PD-L1: 12 (23.1%) patients). Dual expression of druggable protein biomarkers may refine prognostic prediction and stratify high-risk patients for new therapeutic concepts, depending on the metastatic location

A detailed look at the thermal and non-thermal X-ray emission from the Vela supernova remnant with SRG/eROSITA

Aims. Our goal is the characterization of the hot ejecta and shocked interstellar medium (ISM) associated to the Vela supernova remnant (SNR), as well as the relativistic electrons injected into the ambient medium by its central pulsar. To achieve this, we analyze the X-ray data set of Vela acquired by SRG/eROSITA during its first four all-sky surveys. Methods. Apart from multi-band imaging, a quantitative view of the physical parameters affecting the observed thermal and non-thermal emission is obtained by performing spatially resolved X-ray spectroscopy of over 500 independent regions using multi-component spectral models. Results. Imaging demonstrates that the X-ray emission of the Vela SNR consists of at least three morphologically distinct components, with shell-like structures dominating below 0.6 keV, radial outward-directed features becoming apparent at medium energies, and the pulsar wind nebula (PWN) dominating the hard emission above 1.4 keV. Our spectroscopy reveals a highly structured distribution of X-ray absorption column densities, which intriguingly appears anticorrelated with optical extinction measurements. We find evidence for multiple ejecta clumps inside and outside the shell, within which we find a strongly supersolar concentration of neon and magnesium relative to oxygen. This includes the bright shrapnel D, in which we separate shocked ISM in the soft bow-shock from a hot, ejecta-rich clump at its apex, based on the new data. Finally, we find an extremely extended, smoothly decreasing distribution of synchrotron emission from the PWN, which extends up to 14 pc from the pulsar, with a total X-ray luminosity of $1.5\times10^{-3}$ of the pulsar's spin-down power. The extended emission likely traces a relativistic electron population in an ISM-level magnetic field, which requires the existence of a TeV counterpart powered by inverse Compton radiation.Comment: 24+3 pages, 13+4 figures, accepted for publication in Astronomy & Astrophysics; Abstract abridge

A Comprehensive Study about the Role of Crosslink Density on the Tribological Behavior of DLC Coated Rubber

The friction and wear behavior of coated rubber components is strongly dependent on the substrate properties. This work deals with the impact of the crosslink density, i.e., the hardness of the rubber substrate on the tribological performance of uncoated and coated rubber. The hardness of nitrile butadiene rubber (NBR) is varied altering the sulfur content. Both the uncoated and coated rubber samples are characterized in terms of surface and mechanical properties. Tribological tests comprise the examination of the macroscopic contact area and the temperature in the contact zone. It was found that the functional layer enhances the wear resistance significantly. Apparently, the wear and friction behavior of the coated rubber correlates with the hardness and the bulk properties of the substrate material