Petrogenesis of Tertiary Alkaline Magmas in the Siebengebirge, Germany

Basanites from the Tertiary Siebengebirge area of Germany (part of the Central European Volcanic Province; CEVP) have high Mg# (>0·60), moderate to high Cr (>300 ppm) and Ni (>200 ppm) contents and strong light rare earth element enrichment, but systematic depletion in Rb and K relative to trace elements of similar compatibility in anhydrous mantle. Rare earth element melting models can explain the petrogenesis of these basanites in terms of partial melting of a spinel peridotite source containing residual amphibole. It is inferred that amphibole, indicated by the relative K and Rb depletion and the melting model, was precipitated in the spinel peridotite lithospheric mantle beneath the Siebengebirge, by metasomatic fluids or melts from a rising mantle diapir or plume. Alkali basalts and more differentiated rocks have lower Mg# and lower abundances of Ni and Cr, and have undergone fractionation of mainly olivine, clinopyroxene, Fe-Ti oxides, amphibole and plagioclase. Most of the basanites and alkali basalts approach the Sr-Nd-Pb isotope compositions inferred for the European Asthenospheric Reservoir component. Trace element constraints (i.e. low Nb/U and Ce/Pb ratios) and the Sr-Nd-Pb isotope composition of the differentiated rocks indicate that assimilation of lower crustal material has modified the composition of the primary mantle-derived magmas. High 207Pb/204Pb ratios in the differentiated lavas point to assimilation of ancient lower crustal components having high U/Pb and Th/Pb ratios. Relatively shallow melting of inferred amphibole-bearing spinel peridotite sources may suggest an origin from the metasomatized part of the thermal boundary layer. Application of new thermobarometric equations for the basaltic magmas indicates relatively normal mantle potential temperatures (1300-1400°C); thus the inferred mantle ‘baby plume' or ‘hot finger' is not thermally anomalou

Shipment consolidation with two demand classes: Rationing the dispatch capacity

The final publication is available at Elsevier via https://dx.doi.org/10.1016/j.ejor.2018.03.016 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/We analyze the problem faced by a logistics provider that dispatches shipment orders (parcels or larger packages) of two order classes, viz. expedited and regular. Shipment orders arrive according to a compound Poisson process for each class. Upon an arrival, the logistics provider may continue consolidating arriving orders by paying a holding cost. Alternatively, the provider may dispatch, at a fixed cost, a vehicle containing (a portion of) the load consolidated so far. In addition, the provider must specify the composition of each dispatch by allocating (rationing) the volume of the vehicle between expedited and regular shipment orders. We model this problem as a continuous-time Markov Decision Process and minimize the expected discounted total cost. We prove the existence of quantity-based optimal threshold policies under particular conditions. We also structurally analyze the thresholds of these optimal policies. Based on these structural properties, we develop an efficient solution approach for large problem instances which are difficult to solve using the conventional policy-iteration method. For two real-life applications, we show that the quantity-based threshold policies derived using the proposed approach outperform the time policies used in practice.Türkiye Bilimsel ve Teknolojik Araştirma Kurumu [1059B191400567

Accelerated neuronal and synaptic maturation by BrainPhys medium increases Aβ secretion and alters Aβ peptide ratios from iPSC-derived cortical neurons

One of the neuropathological hallmarks of Alzheimer’s disease (AD) is cerebral deposition of amyloid plaques composed of amyloid β (Aβ) peptides and the cerebrospinal fluid concentrations of those peptides are used as a biomarker for AD. Mature induced pluripotent stem cell (iPSC)-derived cortical neurons secrete Aβ peptides in ratios comparable to those secreted to cerebrospinal fluid in human, however the protocol to achieve mature neurons is time consuming. In this study, we investigated if differentiation of neuroprogenitor cells (NPCs) in BrainPhys medium, previously reported to enhance synaptic function of neurons in culture, would accelerate neuronal maturation and, thus increase Aβ secretion as compared to the conventional neural maintenance medium. We found that NPCs cultured in BrainPhys displayed increased expression of markers for cortical deep-layer neurons, increased synaptic maturation and number of astroglial cells. This accelerated neuronal maturation was accompanied by increased APP processing, resulting in increased secretion of Aβ peptides and an increased Aβ38 to Aβ40 and Aβ42 ratio. However, during long-term culturing in BrainPhys, non-neuronal cells appeared and eventually took over the cultures. Taken together, BrainPhys culturing accelerated neuronal maturation and increased Aβ secretion from iPSC-derived cortical neurons, but changed the cellular composition of the cultures

Herpes Simplex Virus 1 and 2 Infections during Differentiation of Human Cortical Neurons

Herpes simplex virus 1 (HSV-1) and 2 (HSV-2) can infect the central nervous system (CNS) with dire consequences; in children and adults, HSV-1 may cause focal encephalitis, while HSV-2 causes meningitis. In neonates, both viruses can cause severe, disseminated CNS infections with high mortality rates. Here, we differentiated human induced pluripotent stem cells (iPSCs) towards cortical neurons for infection with clinical CNS strains of HSV-1 or HSV-2. Progenies from both viruses were produced at equal quantities in iPSCs, neuroprogenitors and cortical neurons. HSV-1 and HSV-2 decreased viability of neuroprogenitors by 36.0% and 57.6% (p < 0.0001), respectively, 48 h post-infection, while cortical neurons were resilient to infection by both viruses. However, in these functional neurons, both HSV-1 and HSV-2 decreased gene expression of two markers of synaptic activity, CAMK2B and ARC, and affected synaptic activity negatively in multielectrode array experiments. However, unaltered secretion levels of the neurodegeneration markers tau and NfL suggested intact axonal integrity. Viral replication of both viruses was found after six days, coinciding with 6-fold and 22-fold increase in gene expression of cellular RNA polymerase II by HSV-1 and HSV-2, respectively. Our results suggest a resilience of human cortical neurons relative to the replication of HSV-1 and HSV-2

'I-I' and 'I-me' : Transposing Buber's interpersonal attitudes to the intrapersonal plane

Hermans' polyphonic model of the self proposes that dialogical relationships can be established between multiple I-positions1 (e.g., Hermans, 2001a). There have been few attempts, however, to explicitly characterize the forms that these intrapersonal relationships may take. Drawing on Buber's (1958) distinction between the 'I-Thou' and 'I-It' attitude, it is proposed that intrapersonal relationships can take one of two forms: an 'I-I' form, in which one I-position encounters and confirms another I-position in its uniqueness and wholeness; and an 'I-Me' form, in which one I-position experiences another I-position in a detached and objectifying way. This article argues that this I-Me form of intrapersonal relating is associated with psychological distress, and that this is so for a number of reasons: Most notably, because an individual who objectifies and subjugates certain I-position cannot reconnect with more central I-positions when dominance reversal (Hermans, 2001a) takes place. On this basis, it is suggested that a key role of the therapeutic process is to help clients become more able to experience moments of I-I intrapersonal encounter, and it is argued that this requires the therapist to confirm the client both as a whole and in terms of each of his or her different voices

Structure and function of mammalian cilia

In the past half century, beginning with electron microscopic studies of 9 + 2 motile and 9 + 0 primary cilia, novel insights have been obtained regarding the structure and function of mammalian cilia. All cilia can now be viewed as sensory cellular antennae that coordinate a large number of cellular signaling pathways, sometimes coupling the signaling to ciliary motility or alternatively to cell division and differentiation. This view has had unanticipated consequences for our understanding of developmental processes and human disease

Swimming like algae: biomimetic soft artificial cilia

Cilia are used effectively in a wide variety of biological systems from fluid transport to thrust generation. Here, we present the design and implemen- tation of artificial cilia, based on a biomimetic planar actuator using soft- smart materials. This actuator is modelled on the cilia movement of the alga Volvox, and represents the cilium as a piecewise constant-curvature robotic actuator that enables the subsequent direct translation of natural articulation into a multi-segment ionic polymer metal composite actuator. It is demonstrated how the combination of optimal segmentation pattern and biologically derived per-segment driving signals reproduce natural cili- ary motion. The amenability of the artificial cilia to scaling is also demonstrated through the comparison of the Reynolds number achieved with that of natural cilia