Genomic comparison between members of the Salinibacteraceae family,and description of a new species of Salinibacter (Salinibacter altiplanensis sp. nov.) isolated from high altitude hypersaline environments of the Argentinian Altiplano

The application of tandem MALDI-TOF MS screening with 16S rRNA gene sequencing of selected isolates has been demonstrated to be an excellent approach for retrieving novelty from large-scale culturing. The application of such methodologies in different hypersaline samples allowed the isolation of the culture-recalcitrant Salinibacter ruber second phylotype (EHB-2) for the first time, as well as a new species recently isolated from the Argentinian Altiplano hypersaline lakes. In this study, the genome sequences of the different species of the phylum Rhodothermaeota were compared and the genetic repertoire along the evolutionary gradient was analyzed together with each intraspecific variability. Altogether, the results indicated an open pan-genome for the family Salinibacteraceae, as well as the codification of relevant traits such as diverse rhodopsin genes, CRISPR-Cas systems and spacers, and one T6SS secretion system that could give ecological advantages to an EHB-2 isolate. For the new Salinibacter species, we propose the name Salinibacter altiplanensis sp. nov. (the designated type strain is AN15^T = CECT 9105^T = IBRC-M 11031^T).     

Effects of UV-C radiation on <Emphasis Type="Italic">Chlorella vulgaris</Emphasis>, a biofilm-forming alga

Photosynthetic biofilms proliferating on heritage monuments represent a major threat for curators leading to biodegradation and esthetic issues. Previous studies demonstrated that UV-C, used as a tool for biofilm eradication, is a promising avenue to combat microbial proliferation. In this study, this environmentally friendly method was tested on biofilm-forming Chlorella vulgaris suspension. Algal physiological response to UV-C was then assessed. Results showed that >?10 kJ m^?2 UV-C exposure was enough to directly kill cells whereas low UV-C exposure reduced quantum yield of photosystem II and inhibited both respiration and photosynthesis. Clear relationships between UV-C exposure times and physiological responses were found. In addition, the use of VIS-light after UV-C treatment enhances chlorophyll bleaching. Our findings contribute to a better understanding of the physiological responses of Chlorella vulgaris to UV-C radiation allowing thus an optimization of the UV-C treatment reported in our previous studies.     

Identification of a Microtubule-associated Motor Protein Essential for Dendritic Differentiation

The quintessential feature of the dendritic microtubule array is its nonuniform pattern of polarity orientation. During the development of the dendrite, a population of plus end–distal microtubules first appears, and these microtubules are subsequently joined by a population of oppositely oriented microtubules. Studies from our laboratory indicate that the latter microtubules are intercalated within the microtubule array by their specific transport from the cell body of the neuron during a critical stage in development (Sharp, D.J., W. Yu, and P.W. Baas. 1995. J. Cell Biol. 130:93– 104). In addition, we have established that the mitotic motor protein termed CHO1/MKLP1 has the appropriate properties to transport microtubules in this manner (Sharp, D.J., R. Kuriyama, and P.W. Baas. 1996. J. Neurosci. 16:4370–4375). In the present study we have sought to determine whether CHO1/MKLP1 continues to be expressed in terminally postmitotic neurons and whether it is required for the establishment of the dendritic microtubule array. In situ hybridization analyses reveal that CHO1/MKLP1 is expressed in postmitotic cultured rat sympathetic and hippocampal neurons. Immunofluorescence analyses indicate that the motor is absent from axons but is enriched in developing dendrites, where it appears as discrete patches associated with the microtubule array. Treatment of the neurons with antisense oligonucleotides to CHO1/MKLP1 suppresses dendritic differentiation, presumably by inhibiting the establishment of their nonuniform microtubule polarity pattern. We conclude that CHO1/MKLP1 transports microtubules from the cell body into the developing dendrite with their minus ends leading, thereby establishing the nonuniform microtubule polarity pattern of the dendrite.     

Kani: a QoS-aware hypervisor-level scheduler for cloud computing environments

Cloud computing environments (CCEs) are expected to deliver their services with qualities in service level agreements. On the other hand, they typically employ virtualization technology to consolidate multiple workloads on the same physical machine, thereby enhancing the overall utilization of physical resources. Most existing virtualization technologies are, however, unaware of their delivered quality of services (QoS). For example, the Xen hypervisor merely focuses on fair sharing of processor resources. We believe that CCEs have got married with traditional virtualization technologies without many traits in common. To bridge the gap between these two technologies, we have designed and implemented Kani, a QoS-aware hypervisor-level scheduler. Kani dynamically monitors the quality of delivered services to quantify the deviation between desired and delivered levels of QoS. Using this information, Kani determines how to allocate processor resources among running VMs so as to meet the expected QoS. Our evaluations of Kani scheduler prototype in Xen show that Kani outperforms the default Xen scheduler namely the Credit scheduler. For example, Kani reduces the average response time to requests to an Apache web server by up to \(93.6\,\%\); improves its throughput by up to \(97.9\,\%\); and mitigates the call setup time of an Asterisk media server by up to \(96.6\,\%\).     

Heterogeneity of KRAS Mutation Status in Rectal Cancer

IntroductionAnti-EGFR targeted therapy is of increasing importance in advanced colorectal cancer and prior KRAS mutation testing is mandatory for therapy. However, at which occasions this should be performed is still under debate. We aimed to assess in patients with locally advanced rectal cancer whether there is intra-specimen KRAS heterogeneity prior to and upon preoperative chemoradiotherapy (CRT), and if there are any changes in KRAS mutation status due to this intervention.ResultsFor 20 (43%) out of the 47 patients, a KRAS mutation was detected. With 12 out of 20, the majority of these mutations affected codon 35. We did not obtained evidence that CRT results in changes of the KRAS mutation pattern. In addition, no intratumoral heterogeneity in the KRAS mutational status could be proven. This was true for both the biopsies prior to CRT and the resection specimens thereafter. The discrepancy observed in some samples when using the SNaPshot™ assay was due to insufficient sensitivity of this technique upon massive tumor regression by CRT as application of the therascreen® KRAS test revealed concordant results.ConclusionOur results indicate that the KRAS mutation status at the primary tumor site of rectal cancer is homogenous. Its assessment for therapeutic decisions is feasible in pre-therapeutic biopsies as well as in post-therapeutic resected specimens. The amount of viable tumor cells seems to be an important determinant for assay sensitivity and should thus be considered for selection of the analytical method.     

Incorporation and activation of a membrane-bound enzyme in bilayers of liposomes

Summary The effects of lipid composition and fluidity of lipid bilayers on incorporation and activation of membrane-bound d-fructose dehydrogenase are described in this study. The incorporation of the enzyme into bilayers of small unilamellar vesicles (SUV) made of several phospholipids resulted in enzyme activation with magnitudes higher than that observed in the presence of Triton X-100, indicating that this higher activation is due to lipid-protein interaction. The activity was highest in the presence of SUV formed by the addition of 10% dl--dipalmitoylphosphatidylethanolamine to l--dimyristoylphosphatidylcholine, which resulted in eightfold higher activation compared with that of the enzyme in its free state. This activation did not appear to be due to the degree of incorporation of the enzyme, indicating that incorporation is distinct from the activation event. Thus, it is probably the lipid environment that leads to higher activation of the enzyme. A break in the Arrhenius plot of the activity of the membrane-bound enzyme at temperatures close to the phase transition of the phospholipid implies that changes in the physical state of the lipid bilayer influence the enzyme activity. Furthermore, immobilization of d-fructose dehydrogenase, previously adsorbed to SUV, on urethane prepolymer also resulted in about eightfold higher activation than that of the free enzyme. Offprint requests to: S. Katoh     

The association between low-carbohydrate diet score and sleep duration among Iranian adults

Sleep and Biological Rhythms - Sleep disorders are linked to obesity, type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). The evidence suggests that dietary carbohydrate content may...     

Distribution of chigger mites (Acari: Trombiculidae) over hosts,parasitopes, collection localities,and seasons in northern Iran

We studied the distribution of chigger mite species over mammal hosts, attachment sites on the host body, habitats, and seasons in Iran. The study was based on 2155 specimens of 36 chigger species collected from 10 species of Muridae, Cricetidae, and Soricidae across six provinces of northern Iran. A high level of mixed infestation by chiggers was recorded—76% of hosts parasitized by chiggers were infested by more than one (2–8) species. Statistically significant differences in the preference for anterior and posterior parts of the host body were found. Three species—Neotrombicula lubrica, N. delijani, and Cheladonta firdousii—preferred the posterior part of the host body; 12 species were characterized by the occurrence in the anterior part and differed from one another by the frequency of presence in the posterior part. One species, Hirsutiella alpina, was found only in the anterior part of the host body (inside the ears of rodents). The most diverse chigger fauna was on the fringe of Golestan National Park (species richness?=?21, Shannon–Wiener index?=?2.823). The chigger fauna of the high-mountain localities on the Alborz Range was the least diverse (species richness?=?16, Shannon–Wiener index?=?2.439). The seasonal aspect of activity was evident for Neotrombicula elegans, which exposed the autumn–winter period of the occurrence on hosts, and N. vernalis, with the winter-spring peak of abundance.