Skin-derived dendritic cells acquire and degrade the scrapie agent following in vitro exposure

The accumulation of the scrapie agent in lymphoid tissues following inoculation via the skin is critical for efficient neuroinvasion, but how the agent is initially transported from the skin to the draining lymph node is not known. Langerhans cells (LCs) are specialized antigen-presenting cells that continually sample their microenvironment within the epidermis and transport captured antigens to draining lymph nodes. We considered LCs probable candidates to acquire and transport the scrapie agent after inoculation via the skin. XS106 cells are dendritic cells (DCs) isolated from mouse epidermis with characteristics of mature LC cells. To investigate the potential interaction of LCs with the scrapie agent XS106 cells were exposed to the scrapie agent in vitro. We show that XS106 cells rapidly acquire the scrapie agent following in vitro exposure. In addition, XS106 cells partially degrade the scrapie agent following extended cultivation. These data suggest that LCs might acquire and degrade the scrapie agent after inoculation via the skin, but data from additional experiments demonstrate that this ability could be lost in the presence of lipopolysaccharide or other immunostimulatory molecules. Our studies also imply that LCs would not undergo maturation following uptake of the scrapie agent in the skin, as the expression of surface antigens associated with LC maturation were unaltered following exposure. In conclusion, although LCs or DCs have the potential to acquire the scrapie agent within the epidermis our data suggest it is unlikely that they become activated and stimulated to transport the agent to the draining lymph node

Developing and applying heterogeneous phylogenetic models with XRate

Modeling sequence evolution on phylogenetic trees is a useful technique in computational biology. Especially powerful are models which take account of the heterogeneous nature of sequence evolution according to the "grammar" of the encoded gene features. However, beyond a modest level of model complexity, manual coding of models becomes prohibitively labor-intensive. We demonstrate, via a set of case studies, the new built-in model-prototyping capabilities of XRate (macros and Scheme extensions). These features allow rapid implementation of phylogenetic models which would have previously been far more labor-intensive. XRate's new capabilities for lineage-specific models, ancestral sequence reconstruction, and improved annotation output are also discussed. XRate's flexible model-specification capabilities and computational efficiency make it well-suited to developing and prototyping phylogenetic grammar models. XRate is available as part of the DART software package: http://biowiki.org/DART .Comment: 34 pages, 3 figures, glossary of XRate model terminolog

Chiral tunneling and the Klein paradox in graphene

The so-called Klein paradox - unimpeded penetration of relativistic particles through high and wide potential barriers - is one of the most exotic and counterintuitive consequences of quantum electrodynamics (QED). The phenomenon is discussed in many contexts in particle, nuclear and astro- physics but direct tests of the Klein paradox using elementary particles have so far proved impossible. Here we show that the effect can be tested in a conceptually simple condensed-matter experiment by using electrostatic barriers in single- and bi-layer graphene. Due to the chiral nature of their quasiparticles, quantum tunneling in these materials becomes highly anisotropic, qualitatively different from the case of normal, nonrelativistic electrons. Massless Dirac fermions in graphene allow a close realization of Klein's gedanken experiment whereas massive chiral fermions in bilayer graphene offer an interesting complementary system that elucidates the basic physics involved.Comment: 15 pages, 4 figure

Psychotherapeutic practice in paediatric oncology: four examples

Psychotherapy, often used with children treated for a solid tumour, is seldom described. We present four examples of such therapies: a mother who refused enucleation for her 7-month-old boy; a boy's jealousy towards his sister who was being treated for a brain tumour; a teenager troubled by his scar; a 7-year-old boy embarrassed by the unconscious memory of his treatment when he was 5 months old. All names have been changed, for reasons of privacy. Psychotherapies aim to help children and parents to cope with the violent experience of having cancer, to recover their freedom of thought and decision-making concerning their life, their place in the family, their body image, their self-esteem, their identity. These descriptions of brief psychotherapy could help paediatricians to gain a more thorough understanding of the child's experience, to improve collaboration with psychotherapists and to confront clinical skills of psychotherapists. © 2000 Cancer Research Campaig

Detection and isolation of black hole attack in mobile ad hoc networks: A review

© 2020 SPIE. Mobile Ad hoc Network or MANET is a wireless network that allows communication between the nodes that are in range of each other and are self-configuring. The distributed administration and dynamic nature of MANET makes it vulnerable to many kind of security attacks. One such attack is Black hole attack which is a well known security threat. A node drops all packets which it should forward, by claiming that it has the shortest path to the destination. Intrusion Detection system identifies the unauthorized users in the system. An IDS collects and analyses audit data to detect unauthorized users of computer systems. This paper aims in identifying Black-Hole attack against AODV with Intrusion Detection System, to analyze the attack and find its countermeasure

Efficacy and safety of cabozantinib for patients with advanced hepatocellular carcinoma based on albumin-bilirubin grade

BACKGROUND: Albumin-bilirubin (ALBI) grade is an objective measure of liver function for patients with hepatocellular carcinoma (HCC). The tyrosine kinase inhibitor cabozantinib is approved for patients with advanced HCC who have received prior sorafenib based on the phase 3 CELESTIAL trial (NCT01908426). Cabozantinib improved overall survival (OS) and progression-free survival (PFS) versus placebo in patients with previously treated HCC. METHODS: Patients were randomised 2:1 to receive cabozantinib 60 mg or placebo orally every day. Clinical outcomes in patients with ALBI grade 1 or 2 at baseline were evaluated in CELESTIAL. ALBI scores were retrospectively calculated based on baseline serum albumin and total bilirubin, with an ALBI grade of 1 defined as  ≤ -2.60 score and a grade of 2 as a score of > -2.60 to  ≤ -1.39. RESULTS: Cabozantinib improved OS and PFS versus placebo in both ALBI grade 1 (hazard ratio [HR] [95% CI]: 0.63 [0.46-0.86] and 0.42 [0.32-0.56]) and ALBI grade 2 (HR [95% CI]: 0.84 [0.66-1.06] and 0.46 [0.37-0.58]) subgroups. Adverse events were consistent with those in the overall population. Rates of grade 3/4 adverse events associated with hepatic decompensation were generally low and were more common among patients in the ALBI grade 2 subgroup. DISCUSSION: These results provide initial support of cabozantinib in patients with advanced HCC irrespective of ALBI grade 1 or 2. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov number, NCT01908426

Effects of growth rate, size, and light availability on tree survival across life stages: a demographic analysis accounting for missing values and small sample sizes.

The data set supporting the results of this article is available in the Dryad repository, http://dx.doi.org/10.5061/dryad.6f4qs. Moustakas, A. and Evans, M. R. (2015) Effects of growth rate, size, and light availability on tree survival across life stages: a demographic analysis accounting for missing values.Plant survival is a key factor in forest dynamics and survival probabilities often vary across life stages. Studies specifically aimed at assessing tree survival are unusual and so data initially designed for other purposes often need to be used; such data are more likely to contain errors than data collected for this specific purpose

Ipl1/aurora kinase suppresses S-CDK-driven spindle formation during prophase I to ensure chromosome integrity during meiosis

Cells coordinate spindle formation with DNA repair and morphological modifications to chromosomes prior to their segregation to prevent cell division with damaged chromosomes. Here we uncover a novel and unexpected role for Aurora kinase in preventing the formation of spindles by Clb5-CDK (S-CDK) during meiotic prophase I and when the DDR is active in budding yeast. This is critical since S-CDK is essential for replication during premeiotic S-phase as well as double-strand break induction that facilitates meiotic recombination and, ultimately, chromosome segregation. Furthermore, we find that depletion of Cdc5 polo kinase activity delays spindle formation in DDR-arrested cells and that ectopic expression of Cdc5 in prophase I enhances spindle formation, when Ipl1 is depleted. Our findings establish a new paradigm for Aurora kinase function in both negative and positive regulation of spindle dynamics