Strategic influences on implementing instructions for future actions

Temporal and strategic factors that might influence the transformation of verbal task rules into functional stimulus–response associations were investigated in three experiments. In a dual task paradigm of the ABBA type participants were presented new S–R instructions for the A-task at the beginning of each trial. On varying proportions of trials No-go signals rendered the instructed A-task mappings irrelevant before instruction implementation was assessed during performance of an unrelated B-task. Our results indicate that participants refrain from implementing the mappings during instruction presentation when No-go signals appear frequently and late (Exp. 2), and that they can interrupt implementing instructed S–R mappings when frequent No-go signals appear early enough during implementation (Exp. 3). When No-go signals are rare and late, however (Exp. 1), the instructed stimulus features always activate their associated responses during performance of the embedded B-task in an automatic manner. Together, these findings suggest that participants strategically control whether or not they implement verbal instructions. Once implemented, however, instructed S–R associations influence behaviour even when the instructed mappings are no longer task relevant

Manipulation of Human Primary Endothelial Cell and Osteoblast Coculture Ratios to Augment Vasculogenesis and Mineralization

Tissue-engineering scaffolds are often seeded with a single type of cell, but there has been more focus on cocultures to improve angiogenesis and bone formation for craniofacial applications. Investigation of bone-derived osteoblasts (OBs) is important because of the use of bone grafts and migration of OBs from native bone into constructs in vivo and therefore, their contribution to bone formation in vivo. The limitation of primary OBs has been their inability to mineralize without osteogenic factors in vitro. Through coculture of OBs and endothelial cells (ECs) and manipulation of the coculture ratio, mineralization can be achieved without osteogenic media or additional growth factors, thus enhancing their utility for tissue-engineering applications. An optimal ratio of EC/OB for vasculogenesis and mineralization has not been determined for human primary cells. Human umbilical vein ECs were cultured with normal human primary OBs in different EC/OB ratios, namely, 10:1, 5:1, 1:1, 1:5, and 1:10 with EC and OB monocultures as controls. The number of vasculogenic networks in a collagen matrix was highest in ratios of 5:1 and 1:1. ECs lined up and formed capillary-like networks by day 10, which was not seen in the other groups. On polystyrene, cells were cocultured with ECs and OBs in direct contact (direct coculture) or separated by a transwell membrane (indirect coculture). At day 21, Alizarin Red staining showed mineralization on the 1:5 and 1:10 direct coculture ratios, with 1:5 having more mineralization nodules present than 1:10. No mineralization was seen in other direct coculture ratios or in any of the indirect coculture ratios. Alkaline phosphatase secretion was highest in the 1:5 direct coculture group. Vascular endothelial growth factor secretion from OBs was present in the 1:5 and 1:10 direct coculture ratios at all time points and inhibited after day 1 in other coculture groups. To improve vasculogenesis, cocultures of primary human ECs and OBs in ratios of 5:1 should be used, but to improve bone formation, the 1:5 direct coculture ratio results in most mineralization

Beyond osteogenesis: an in vitro comparison of the potentials of six bone morphogenetic proteins

Bone morphogenetic proteins (BMPs) other than the clinically available BMP-2 and BMP-7 may be useful for improving fracture healing through both increasing osteogenesis and creating a favorable healing environment by altering cytokine release by endogenous cells. Given the spectrum of potential applications for BMPs, the objective of this study was to evaluate various BMPs under a variety of conditions to provide further insight into their therapeutic capabilities. The alkaline phosphatase (ALP) activity of both C(2)C(12) and human adipose-derived stem cells (hASCs) was measured after exposure of increasing doses of recombinant human BMP-2, -4, -5, -6, -7, or -9 for 3 and 7 days. BMPs-2, -4, -5, -6, -7, and -9 were compared in terms of their ability to affect the release of stromal derived factor-1 (SDF-1), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (b-FGF) from human bone marrow stromal cells (hBMSCs). Gene expression of ALP, osteocalcin, SDF-1, VEGF, and b-FGF following shRNA-mediated knockdown of BMP-2 and BMP-6 in hBMSCs or human osteoblasts under osteogenic differentiation conditions was also evaluated. Collectively, BMPs-6 and -9 produced the greatest osteogenic differentiation of C(2)C(12) and hASCs as determined by ALP. The hBMSC secretion of SDF-1 was most affected by BMP-5, VEGF by BMP-4, and b-FGF by BMP-2. The knockdown of BMP-2 in BMSCs had no effect on any of the genes measured whereas BMP-6 knockdown in hBMSCs caused a significant increase in VEGF gene expression. BMP-2 and BMP-6 knockdown in human osteoblasts caused significant increases in VEGF gene expression and trends toward decreases in osteocalcin expression. These findings support efforts to study other BMPs as potential bone graft supplements, and to consider combined BMP delivery for promotion of multiple aspects of fracture healing

Heat extraction capacity and its attenuation of deep borehole heat exchanger array

A model is proposed to analyze the heat transfer of deep borehole heat exchanger (DBHE)arrays. Based on this, a dimension reduction algorithm is proposed for the numerical simulation of heat transfer of DBHE arrays, which can improve calculation speed by several orders of magnitude compared with that by the CFD software. An index of heat extraction capacity (HECI) is adopted to evaluate the heat extraction capacity of DBHE arrays. The influence of borehole spacing, operation time, annual heating duration, terrestrial heat flow rate, borehole depth, soil thermal parameters, pipe diameter and circulating fluid flow rate on DBHE array heat extraction capacity and its attenuation are analyzed. The results show that the borehole spacing, operation time, and annual heating duration all have apparent influence on DBHE array heat extraction capacity and its attenuation rate, while the others only have apparent influence on the heat extraction capacity. According to the calculation results, when the DBHE arrays have a service lifetime of 20–50 years, the recommended borehole spacing range is 40–70 m

Characterization of THB1, a Chlamydomonas reinhardtii truncated hemoglobin: linkage to nitrogen metabolism and identification of lysine as the distal heme ligand

The nuclear genome of the model organism Chlamydomonas reinhardtii contains genes for a dozen hemoglobins of the truncated lineage. Of those, THB1 is known to be expressed, but the product and its function have not yet been characterized. We present mutagenesis, optical, and nuclear magnetic resonance data for the recombinant protein and show that at pH near neutral in the absence of added ligand, THB1 coordinates the heme iron with the canonical proximal histidine and a distal lysine. In the cyanomet state, THB1 is structurally similar to other known truncated hemoglobins, particularly the heme domain of Chlamydomonas eugametos LI637, a light-induced chloroplastic hemoglobin. Recombinant THB1 is capable of binding nitric oxide (NO(*)) in either the ferric or ferrous state and has efficient NO(*) dioxygenase activity. By using different C. reinhardtii strains and growth conditions, we demonstrate that the expression of THB1 is under the control of the NIT2 regulatory gene and that the hemoglobin is linked to the nitrogen assimilation pathway

Geologically constrained evolutionary geomechanical modelling of diapir and basin evolution: a case study from the Tarfaya basin, West African coast

We systematically incorporate burial history, sea floor geometry and tectonic loads from a sequential kinematic restoration model into a 2D evolutionary geomechanical model that simulates the formation of the Sandia salt diapir, Tarfaya basin, NW African Coast. We use a poro-elastoplastic description for the sediment behaviour and a viscoplastic description for the salt. Sedimentation is coupled with salt flow and regional shortening to determine the sediment porosity and strength and to capture the interaction between salt and sediments. We find that temporal and spatial variation in sedimentation rate is a key control on the kinematic evolution of the salt system. Incorporation of sedimentation rates from the kinematic restoration at a location east of Sandia leads to a final geomechanical model geometry very similar to that observed in seismic reflection data. We also find that changes in the variation of shortening rates can significantly affect the present-day stress state above salt. Overall, incorporating kinematic restoration data into evolutionary models provides insights into the key parameters that control the evolution of geologic systems. Furthermore, it enables more realistic evolutionary geomechanical models, which, in turn, provide insights into sediment stress and porosity

Differential Dynamics of Transposable Elements during Long-Term Diploidization of Nicotiana Section Repandae (Solanaceae) Allopolyploid Genomes

PubMed ID: 23185607This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Action selection and action awareness

Human actions are often classified as either internally generated, or externally specified in response to environmental cues. These two modes of action selection have distinct neural bases, but few studies investigated how the mode of action selection affects the subjective experience of action. We measured the experience of action using the subjective compression of the interval between actions and their effects, known as ‘temporal binding’. Participants performed either a left or a right key press, either in response to a specific cue, or as they freely chose. Moreover, the time of each keypress could either be explicitly cued to occur in one of two designated time intervals, or participants freely chose in which interval to act. Each action was followed by a specific tone. Participants judged the time of their actions or the time of the tone. Temporal binding was found for both internally generated and for stimulus-based actions. However, the amount of binding depended on whether or not both the choice and the timing of action were selected in the same way. Stronger binding was observed when both action choice and action timing were internally generated or externally specified, compared to conditions where the two parameters were selected by different routes. Our result suggests that temporal action–effect binding depends on how actions are selected. Binding is strongest when actions result from a single mode of selection

Insights from Amphioxus into the Evolution of Vertebrate Cartilage

Central to the story of vertebrate evolution is the origin of the vertebrate head, a problem difficult to approach using paleontology and comparative morphology due to a lack of unambiguous intermediate forms. Embryologically, much of the vertebrate head is derived from two ectodermal tissues, the neural crest and cranial placodes. Recent work in protochordates suggests the first chordates possessed migratory neural tube cells with some features of neural crest cells. However, it is unclear how and when these cells acquired the ability to form cellular cartilage, a cell type unique to vertebrates. It has been variously proposed that the neural crest acquired chondrogenic ability by recruiting proto-chondrogenic gene programs deployed in the neural tube, pharynx, and notochord. To test these hypotheses we examined the expression of 11 amphioxus orthologs of genes involved in neural crest chondrogenesis. Consistent with cellular cartilage as a vertebrate novelty, we find that no single amphioxus tissue co-expresses all or most of these genes. However, most are variously co-expressed in mesodermal derivatives. Our results suggest that neural crest-derived cartilage evolved by serial cooption of genes which functioned primitively in mesoderm

Forschungsstudie: Alterssicherung von Personen mit Migrationshintergrund; Endbericht zum Auftrag des BMAS, Projektgruppe "Soziale Sicherheit und Migration" vom 02.01.2009

Aufgrund der demographischen Entwicklung und unter Annahme weitgehend stabiler Remigrationsmuster ist ein Anstieg des Bevölkerungsanteils älterer Menschen mit Migrationshintergrund zu erwarten. Viele der derzeit in Deutschland lebenden Migranten werden daher ihren Lebensabend hier verbringen. Ziel dieser Studie ist die vergleichende Darstellung der sozioökonomischen Lage der Migrantenpopulation und der autochthonen Bevölkerung. Dabei wird die Lebenslage von Personen im Rentenalter und von älteren Erwerbspersonen ab 45 Jahren vor dem Hintergrund ihrer spezifischen Bildungs- und Erwerbsverläufe untersucht. Damit wird eine belastbare empirische Grundlage für Handlungsempfehlungen zur Verbesserung der sozialen Lage von Frauen und Männern mit Migrationshintergrund im Alter geliefert