144 research outputs found
Normal Utilization as the Adjusting Variable in Neo-Kaleckian Growth Models: A Critique
As well-known, the canonical Neo-Kaleckian growth model fails to reconcile actual and normal rates of utilization in equilibrium. Some recent contributions revive an old proposal for solving this problem β making the normal rate of utilization an endogenous variable that converges to the actual utilization rate β justifying it with new, micro-founded premises. We argue that these new justifications for the convergence of normal to actual utilization do not stand closer scrutiny. First, the proposed microeconomic model relies on various restrictive assumptions, some of which are mutually inconsistent. Second, the derivation of the macroeconomic adjustment mechanism from the microeconomic analysis involves a logical leap, that can be justified only by a very arbitrary assumption with little economic justification. Finally, we discuss the way in which this mechanism has been incorporated into the Neo-Kaleckian growth model by proposers of this approach. We show that, even if one puts aside, for the sake of argument, the first two points, the existence of autonomous components of demand is sufficient to invalidate the resulting macroeconomic model
Simulations of the High-Energy Beam-Transport (HEBT) section at FRANZ
The neutron source FRANZ (Frankfurter Neutronenquelle am
Stern-Gerlach-Zentrum), which is currently under construction, will be the neutron source with the highest intensity in the nuclear-astrophysically relevant energy
region. The TraceWin code was used to design the High-Energy Beam-Transport section with regard to the experimental requirements at different target positions
Approaching the Gamow Window with Stored Ions : Direct Measurement of Xe 124 (p,Ξ³) in the ESR Storage Ring
Β© 2019 American Physical Society. All rights reserved.We report the first measurement of low-energy proton-capture cross sections of Xe124 in a heavy-ion storage ring. Xe12454+ ions of five different beam energies between 5.5 and 8 AMeV were stored to collide with a windowless hydrogen target. The Cs125 reaction products were directly detected. The interaction energies are located on the high energy tail of the Gamow window for hot, explosive scenarios such as supernovae and x-ray binaries. The results serve as an important test of predicted astrophysical reaction rates in this mass range. Good agreement in the prediction of the astrophysically important proton width at low energy is found, with only a 30% difference between measurement and theory. Larger deviations are found above the neutron emission threshold, where also neutron and Ξ³ widths significantly impact the cross sections. The newly established experimental method is a very powerful tool to investigate nuclear reactions on rare ion beams at low center-of-mass energies.Peer reviewedFinal Published versio
Neutron activation of Ga and Ga at kBTβ25 keV
Background: About 50% of heavy elements are produced by the slow neutron capture process (s process) in stars. The element gallium is mostly produced during the weak s process in massive stars.
Purpose: Our activation at kTβ25 keV is the first experiment in a series of activation and time-of-flight measurements on Ga and Ga relevant for astrophysics.
Methods: We activated Ga and Ga with a neutron distribution that corresponds to a quasistellar distribution with kT=25 keV at the Joint Research Centre (JRC), Geel, Belgium. Protons were provided by an electrostatic Van de Graaff accelerator to produce neutrons via the reaction Li(p,n). The produced activity was measured via the Ξ³ emission by the decaying product nuclei by high-purity germanium detectors.
Results: We provide spectrum-averaged cross sections (SACS) and ratios of the cross sections Ο/Ο for the neutron spectrum of the activation. We obtain values of Ο=(186Β±12) mb and Ο = (112Β±7) mb, and cross section ratios of Ο/Ο=0.29Β±0.02 and Ο/Ο = 0.17Β±0.01.
Conclusions: Our data disagree with the available evaluated data provided by KADoNiS v0.3, our cross-section ratio is about 20% higher for Ga and about 20% lower for Ga
A Soluble Form of the High Affinity IgE Receptor, Fc-Epsilon-RI, Circulates in Human Serum
Soluble IgE receptors are potential in vivo modulators of
IgE-mediated immune responses and are thus important for our basic understanding
of allergic responses. We here characterize a novel soluble version of the
IgE-binding alpha-chain of Fc-epsilon-RI (sFcΞ΅RI), the high affinity
receptor for IgE. sFcΞ΅RI immunoprecipitates as a protein of βΌ40 kDa and
contains an intact IgE-binding site. In human serum, sFcΞ΅RI is found as a
soluble free IgE receptor as well as a complex with IgE. Using a newly
established ELISA, we show that serum sFcΞ΅RI levels correlate with serum IgE
in patients with elevated IgE. We also show that serum of individuals with
normal IgE levels can be found to contain high levels of sFcΞ΅RI. After
IgE-antigen-mediated crosslinking of surface FcΞ΅RI, we detect sFcΞ΅RI in
the exosome-depleted, soluble fraction of cell culture supernatants. We further
show that sFcΞ΅RI can block binding of IgE to FcΞ΅RI expressed at the cell
surface. In summary, we here describe the alpha-chain of FcΞ΅RI as a
circulating soluble IgE receptor isoform in human serum
CCL25/CCR9 Interactions Regulate Large Intestinal Inflammation in a Murine Model of Acute Colitis
CCL25/CCR9 is a non-promiscuous chemokine/receptor pair and a key regulator of leukocyte migration to the small intestine. We investigated here whether CCL25/CCR9 interactions also play a role in the regulation of inflammatory responses in the large intestine.Acute inflammation and recovery in wild-type (WT) and CCR9(-/-) mice was studied in a model of dextran sulfate sodium (DSS)-induced colitis. Distribution studies and phenotypic characterization of dendritic cell subsets and macrophage were performed by flow cytometry. Inflammatory bowel disease (IBD) scores were assessed and expression of inflammatory cytokines was studied at the mRNA and the protein level.CCL25 and CCR9 are both expressed in the large intestine and are upregulated during DSS colitis. CCR9(-/-) mice are more susceptible to DSS colitis than WT littermate controls as shown by higher mortality, increased IBD score and delayed recovery. During recovery, the CCR9(-/-) colonic mucosa is characterized by the accumulation of activated macrophages and elevated levels of Th1/Th17 inflammatory cytokines. Activated plasmacytoid dendritic cells (DCs) accumulate in mesenteric lymph nodes (MLNs) of CCR9(-/-) animals, altering the local ratio of DC subsets. Upon re-stimulation, T cells isolated from these MLNs secrete significantly higher levels of TNFΞ±, IFNΞ³, IL2, IL-6 and IL-17A while down modulating IL-10 production.Our results demonstrate that CCL25/CCR9 interactions regulate inflammatory immune responses in the large intestinal mucosa by balancing different subsets of dendritic cells. These findings have important implications for the use of CCR9-inhibitors in therapy of human IBD as they indicate a potential risk for patients with large intestinal inflammation
Ubiquitylation in ERAD: Reversing to Go Forward?
Proteins are co-translationally inserted into the endoplasmic reticulum (ER) where they undergo maturation. Homeostasis in the ER requires a highly sensitive and selective means of quality control. This occurs through ER-associated degradation (ERAD).This complex ubiquitin-proteasomeβmediated process involves ubiquitin conjugating enzymes (E2) and ubiquitin ligases (E3),lumenal and cytosolic chaperones, and other proteins, including the AAA ATPase p97 (VCP; Cdc48 in yeast). Probing of processes involving proteasomal degradation has generally depended on proteasome inhibitors or knockdown of specific E2s or E3s. In this issue of PLoS Biology, Ernst et al. demonstrate the utility of expressing the catalytic domain of a viral deubiquitylating enzyme to probe the ubiquitin system. Convincing evidence is provided that deubiquitylation is integral to dislocation of ERAD substrates from the ER membrane. The implications of this work for understanding ERAD and the potential of expressing deubiquitylating enzyme domains for studying ubiquitin-mediated processes are discussed
Effective combination chemotherapy with paclitaxel and cisplatin with or without human granulocyte colony-stimulating factor and/or erythropoietin in patients with advanced gastric cancer
A phase II trial was performed to determine the antitumour efficacy and tolerance of combined paclitaxel and cisplatin with or without hematopoetic growth factor support in patients with advanced gastric cancer. Forty-five patients with histologically confirmed metastatic gastric cancer were entered in this trial. Treatment consisted of 2-weekly courses of paclitaxel 160βmg per m2 and cisplatin 60βmg per m2 both given on day 1. Depending on absolute neutrophil counts on the days of scheduled chemotherapeutic drug administration (1000β2000 per ΞΌl), a 5-day course of human granulocyte colony-stimulating factor 5βΞΌgβkgβ1 per day was given subcutaneously; in addition, if haemoglobin was <12.0βmgβdlβ1, erythropoietin 10β000βIU was administered subcutaneously three times per week. The confirmed overall response rate (intent-to-treat) was 44%, including five complete (11%) and 15 partial remissions (33%). Twelve patients had stable disease (27%), 11 (24%) progressed while on chemotherapy, and two patients were not evaluable. The median time to response was 3 months, the median time to progression 7.0 months, and the median survival time was 11.2 months with 12 patients currently alive. Haematologic toxicity was common, though WHO grade 4 neutropenia occurred in only five patients (11%). Apart from total alopecia in 16 patients (36%), severe non-haematologic adverse reactions included grade 3 peripheral neuropathy in six (13%) and anaphylaxis in two patients. In addition, there was one patient each who experienced grade 3 emesis, diarrhea, and infection, respectively. Our data suggest that the combination of paclitaxel and cisplatin with or without G-CSF and/or erythropoietin has promising therapeutic activity in patients with advanced gastric cancer
Enzymatic Blockade of the Ubiquitin-Proteasome Pathway
Ubiquitin-dependent processes control much of cellular physiology. We show that expression of a highly active, Epstein-Barr virus-derived deubiquitylating enzyme (EBV-DUB) blocks proteasomal degradation of cytosolic and ER-derived proteins by preemptive removal of ubiquitin from proteasome substrates, a treatment less toxic than the use of proteasome inhibitors. Recognition of misfolded proteins in the ER lumen, their dislocation to the cytosol, and degradation are usually tightly coupled but can be uncoupled by the EBV-DUB: a misfolded glycoprotein that originates in the ER accumulates in association with cytosolic chaperones as a deglycosylated intermediate. Our data underscore the necessity of a DUB activity for completion of the dislocation reaction and provide a new means of inhibition of proteasomal proteolysis with reduced cytotoxicity.National Institutes of Health (U.S.)EMBO (long term Fellowship 2008-379)Boehringer Ingelheim Fond
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