The upgrade of the LHCb trigger system

The LHCb experiment will operate at a luminosity of $2\times10^{33}$ cm$^{-2}$s$^{-1}$ during LHC Run 3. At this rate the present readout and hardware Level-0 trigger become a limitation, especially for fully hadronic final states. In order to maintain a high signal efficiency the upgraded LHCb detector will deploy two novel concepts: a triggerless readout and a full software trigger.Comment: Proceedings of the Workshop on Intelligent Trackers, 14-16 May 2014, University of Pennsylvani

The decrease in growth hormone (GH) response after repeated stimulation with GH-Releasing hormone is partly caused by an elevation of somatostatin tonus.

Repeated injection of GHRH leads to a decrease in the GH response in normal subjects. Arginine (Arg) stimulates GH secretion by suppression of hypothalamic somatostatin. To confirm these findings, eight normal men were examined in a series of five settings: test 1 (GHRH/GHRH-TRH), 100 micrograms GHRH injected iv, followed by 100 micrograms GHRH, iv, after 120 min and 200 micrograms TRH, iv, after 150 min; test 2 (GHRH/Arg-TRH), like test 1, but instead of the second GHRH injection, a 30 g Arg infusion over 30 min; test 3 (GHRH/GHRH-Arg-TRH), like test 1, but additionally a 30 g Arg infusion after 120 min; test 4 (GHRH-Arg-TRH), iv GHRH and Arg infusion initially, followed by iv TRH after 30 min; and test 5 (TRH), 200 micrograms TRH, iv, at 0 min. For statistical evaluation, the area under the GH curve (AUC) from 0-120 min was compared with the AUC from 120-240 min. The GH response to the second administration of GHRH was significantly lower (P < 0.02) than the first increase [AUC, 0.5 +/- 0.01 min.mg/L (mean +/- SE) vs. 1.2 +/- 0.3]. No significant differences were found between the GH responses to either GHRH or Arg alone (AUC, 0.9 +/- 0.2 min.mg/L vs. 0.9 +/- 0.2). A larger GH increase (P < 0.02) was seen after GHRH-Arg compared to GHRH alone (AUC, 1.9 +/- 0.4 min.mg/L vs. 1.2 +/- 0.3). The GH response (P < 0.02) to GHRH-Arg stimulation was lower after previous GHRH injection than after GHRH-Arg stimulation alone (AUC, 1.9 +/- 0.4 min.mg/L vs. 3.5 +/- 0.9). There was a statistically significant difference between the TRH-stimulated TSH response in test 4 compared to that in test 5. We could show that decreasing GH responses to repeated GHRH can be avoided by a combined stimulation with GHRH/Arg. These findings suggest that the decreased GH response to a second GHRH bolus may be partly due to an elevated hypothalamic somatostatin secretion, which can be suppressed by Arg. The lower GH response to GHRH-Arg stimulation after a previous GHRH bolus suggests, furthermore, that the readily available GH pool in the human pituitary may be limited

Var transcription profiling of Plasmodium falciparum 3D7: assignment of cytoadherent phenotypes to dominant transcripts

Background\ud Cytoadherence of Plasmodium falciparum -infected red blood cells is mediated by var gene-encoded P. falciparum erythrocyte membrane protein-1 and host receptor preference depends in most cases on which of the 50–60 var genes per genome is expressed. Enrichment of phenotypically homogenous parasites by panning on receptor expressing cells is fundamental for the identification of the corresponding var transcript.\ud \ud \ud Methods\ud P. falciparum 3D7 parasites were panned on several transfected CHO-cell lines and their var transcripts analysed by i) reverse transcription/PCR/cloning/sequencing using a universal DBLα specific oligonucleotide pair and ii) by reverse transcription followed by quantitative PCR using 57 different oligonucleotide pairs.\ud \ud \ud Results\ud Each cytoadherence selected parasite line also adhered to untransfected CHO-745 cells and upregulation of the var gene PFD995/PFD1000c was consistently associated with cytoadherence to all but one CHO cell line. In addition, parasites panned on different CHO cell lines revealed candidate var genes which reproducibly associated to the respective cytoadherent phenotype. The transcription profile obtained by RT-PCR/cloning/sequencing differed significantly from that of RT-quantitative PCR.\ud \ud \ud Conclusion\ud Transfected CHO cell lines are of limited use for the creation of monophenotypic cytoadherent parasite lines. Nevertheless, 3D7 parasites can be reproducibly selected for the transcription of different determined var genes without genetic manipulation. Most importantly, var transcription analysis by RT-PCR/cloning/sequencing may lead to erroneous interpretation of var transcription profiles.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) [06/51873-0]CNP

Charakterisierung der essentiellen Eisen-Schwefel-Cluster Biosynthesekomponenten des Suf-Systems in Bacillus subtilis

Eisen-Schwefel-Cluster gehören zu den wichtigsten und vielseitigsten Cofaktoren in der Natur. Viele essentielle Stoffwechselwege, wie der Citratzyklus oder die Atmungskette sind direkt abhängig von Eisen-Schwefel-Enzymen. Durch die Toxizität von freiem Eisen und Sulfid sind die Organismen auf eine streng regulierte Biosynthese der Fe/S-Cluster angewiesen. Hierfür haben sich verschiedene Maschinerien entwickelt, die in allen Fällen auf drei essentiellen Kernkomponenten aufbauen: Einem Scaffoldprotein, auf dem der Cluster assembliert wird, eine Cysteindesulfurase zur Mobilisierung von Schwefel aus Cystein und ein Eisendonor, vermutlich ein Homologes von Frataxin. In dieser Arbeit wurden die Kernkomponenten des Eisen-Schwefel-Cluster-Biosynthese-systems von Bacillus subtilis untersucht. Nach der Identifizierung des potentiellen SufCDSUB-Systems durch BLAST-Analyse, wurde durch in vivo Untersuchungen an Deletionsmutanten zunächst das putative Scaffoldprotein SufU identifiziert. Es konnte gezeigt werden, dass eine verringerte Expression von SufU drastische Auswirkungen auf das Wachstum sowie eine reduzierte Aktivität von Eisen-Schwefel-Proteinen in Bacillus subtilis zur Folge hat. Weiterhin konnte in vitro gezeigt werden, dass SufU in der Lage ist, einen Fe/S-Cluster zu binden und diesen auf apo-Fe/S-Proteine zu transferieren. Neben dem Scaffoldprotein wurde die zweite Kernkomponente der Fe/S-Cluster Biosynthese charakterisiert: die Cysteindesulfurase SufS. Hier konnte gezeigt werden, dass SufS nur sehr geringe Aktivität aufweist und erst durch das Scaffoldprotein SufU aktiviert wird. Die Aktivierung von SufS ist dabei sowohl von der Cystein- als auch von der SufU-Konzentration abhängig. Durch weitere kinetische Untersuchungen konnte gezeigt werden, dass der Sulfidtransfer zwischen SufS und SufU einem Ping-Pong Reaktionsmechanismus folgt und Cystein 41 in SufU für den Mechanismus des Sulfidtransfers eine entscheidende Rolle spielt. Abschließend wurde Fra (YdhG) charakterisiert; ein Protein, das stukturhomolog zu humanem Frataxin ist. Eine Fra-Deletionsmutante zeigte einen Phänotyp, der auf eine deutliche Störung des gesamten Eisenhaushalts hindeutet. In vitro konnte gezeigt werden, dass Fra in der Lage ist Eisen zu binden und als Eisendonor für den Fe/S-Cluster Aufbau von SufU zu wirken

Fragment emission in high-energy heavy-ion reactions

We present a theoretical description of nuclear collisions which consists of a three-dimensional fluid-dynamical model, a chemical equilibrium breakup calculation for local light fragment (i.e., p, n, d, t, 3He, and 4He) production, and a final thermal evaporation of these particles. The light fragment cross sections and some properties of the heavy target residues are calculated for the asymmetric system Ne+U at 400 MeV/N. The results of the model calculations are compared with recent experimental data. Several observable signatures of the collective hydrodynamical processes are consistent with the present data. An event-by-event analysis of the flow patterns of the various clusters is proposed which can yield deeper insight into the collision dynamics

Stimuli sensitive microcapsules with macroporous polymer shells

Porous microcapsules are of great interest in diverse applications, ranging from encapsulation for controlled release, to catalyst support to filtration and purification systems in analytical science. Here, we demonstrate a novel method to obtain porous microcapsules with polymer shells whose macroporosity and mechanical properties can be tuned within a wide range. Microcapsules are produced by microfluidics, using a co-flow flow-focusing glass capillary device to make water-oil-water (W/O/W) double emulsion templates. A mixture of acrylate monomers (glycidyl methacrylate and ethylene glycol dimethacrylate) and porogens (phthalate-based, alkanes or linear alcohols) is used as oil phase. Heterogeneous polymerization of the acrylate monomers leads to a biphasic structure in the capsule shell, in which a network of polymer beads is permeated by the liquid porogen. In the presence of hydrophobic porogens, the formation of a thin and tight polymer skin is observed on the inner and outer surfaces of the shell. This leads to sealed pores within the shell of the microcapsules, which can be used for the storage of chemicals in addition to the main encapsulant in the capsule core. As a proof of concept of such co-encapsulation of reactive compounds, we produced capsules loaded with separately stored monomers commonly used for two-components epoxy resins. Such capsules provide a rich platform for the design of solid adhesive and self-healing materials. Furthermore, the utilization of porogens with low boiling point, such as a short alkanes, leads to thermosensitive capsules that explosively release their content within seconds. Combining these capsules with magnetic particles heated by magnetic hyperthermia, we achieved a magnetic release of the capsules content within seconds and without over-heating the surrounding matrix. Incorporation of glycidyl methacrylate monomers results in polymer capsules with epoxy-functionalized surfaces, which can be further reacted with amine-based functional compounds. Exploiting such epoxy groups as anchors for grafting of sensitive polymers and for covalently attaching nanoparticles, we prepared multi-functional capsules with tailored shell structure and surface chemistries. Please click Additional Files below to see the full abstract

Kiri Karl Morgensternile, Quedlingburg

http://tartu.ester.ee/record=b1816819~S1*es

2 kirja Karl Morgensternile, Quedlinburg

http://tartu.ester.ee/record=b1742081~S1*es