Pre-Eruptive Evolution of Izu-Bonin Boninite Melts: Mixing, Cooling, and Crystallization

Subduction is the geologic process in which one tectonic plate moves beneath another as it sinks into the Earth’s mantle. Subduction initiation in the Izu-Bonin Marianas system is the result of a gravitational failure during which one tectonic plate (the Pacific plate) spontaneously sinks beneath another (the Philippne Sea plate). Fluids released by the sinking plate that caused the overlying mantle to melt by reducing its meltimg temperature, forming the Izu-Bonin Mariana island arc system. The resulting melts initially have the chemical compositions that are rich in silica and magnesia, and highly depleted in other elements, refered to a boninite or high-Mg andesite. The goal of this thesis is to examine the chemical evolution of boninite lavas as they ascend from the mantle to the surface. This study intergrates observations of crystal chemistry and textures, with models that show how crystallization alters the chemistry of the melt. Melts begin crystallizing near the base of the crust (≈7-10 km below the surface) and continue to crystallize as they ascend through the crust and into a magma chamber. Separate melts interact and mixwithin this magma chamber, forming a single hybridized melt. In some cases, this mixing results in the eruption of boninite lavas. Our results also indicate that low-silica boninite and high-silica boninite come from mantle sources with different chemical compositions. It is unclear whether there was mantle source or whether the mantle source is just chemically evolving as melting continues. This question, along with questions on the chemical evolution of subduction fluids, will be examined during future chemical studies of these boninite lavas

Emerging role of contact-mediated cell communication in tissue development and diseases

This is the final version. Available on open access from Springer via the DOI in this recordCells of multicellular organisms are in continuous conversation with the neighbouring cells. The sender cells signal the receiver cells to influence their behaviour in transport, metabolism, motility, division, and growth. How cells communicate with each other can be categorized by biochemical signalling processes, which can be characterised by the distance between the sender cell and the receiver cell. Existing classifications describe autocrine signals as those where the sender cell is identical to the receiver cell. Complementary to this scenario, paracrine signalling describes signalling between a sender cell and a different receiver cell. Finally, juxtacrine signalling describes the exchange of information between adjacent cells by direct cell contact, whereas endocrine signalling describes the exchange of information, e.g., by hormones between distant cells or even organs through the bloodstream. In the last two decades, however, an unexpected communication mechanism has been identified which uses cell protrusions to exchange chemical signals by direct contact over long distances. These signalling protrusions can deliver signals in both ways, from sender to receiver and vice versa. We are starting to understand the morphology and function of these signalling protrusions in many tissues and this accumulation of findings forces us to revise our view of contact-dependent cell communication. In this review, we will focus on the two main categories of signalling protrusions, cytonemes and tunnelling nanotubes. These signalling protrusions emerge as essential structural components of a vibrant communication network in the development and tissue homeostasis of any multicellular organism.BM and SS are funded by a LSI start-up grant awarded to SS

The function of endocytosis in Wnt signaling

This is the final version of the article. Available from Springer Verlag via the DOI in this record.Wnt growth factors regulate one of the most important signaling networks during development, tissue homeostasis and disease. Despite the biological importance of Wnt signaling, the mechanism of endocytosis during this process is ill described. Wnt molecules can act as paracrine signals, which are secreted from the producing cells and transported through neighboring tissue to activate signaling in target cells. Endocytosis of the ligand is important at several stages of action: One central function of endocytic trafficking in the Wnt pathway occurs in the source cell. Furthermore, the β-catenin-dependent Wnt ligands require endocytosis for signal activation and to regulate gene transcription in the responding cells. Alternatively, Wnt/β-catenin-independent signaling regulates endocytosis of cell adherence plaques to control cell migration. In this comparative review, we elucidate these three fundamental interconnected functions, which together regulate cellular fate and cellular behavior. Based on established hypotheses and recent findings, we develop a revised picture for the complex function of endocytosis in the Wnt signaling network.Funding was provided by Deutsche Forschungsgemeinschaft (Grant no. SCHO847-5) and the University of Exeter (GB) (LSI Start-up Grant)

The Tale of the Three Brothers – Shh, Wnt, and Fgf during Development of the Thalamus

The thalamic complex is an essential part of the brain that requires a combination of specialized activities to attain its final complexity. In the following review we will describe the induction process of the mid-diencephalic organizer (MDO) where three different signaling pathways merge: Wnt, Shh, and Fgf. Here, we dissect the function of each signaling pathway in the thalamus in chronological order of their appearance. First we describe the Wnt mediated induction of the MDO and compartition of the caudal forebrain, then the Shh mediated determination of proneural gene expression before discussing recent progress in characterizing Fgf function during thalamus development. Then, we focus on transcription factors, which are regulated by these pathways and which play a pivotal role in neurogenesis in the thalamus. The three signaling pathways act together in a strictly regulated chronology to orchestrate the development of the entire thalamus

Neurogenesis in zebrafish – from embryo to adult

Neurogenesis in the developing central nervous system consists of the induction and proliferation of neural progenitor cells and their subsequent differentiation into mature neurons. External as well as internal cues orchestrate neurogenesis in a precise temporal and spatial way. In the last 20 years, the zebrafish has proven to be an excellent model organism to study neurogenesis in the embryo. Recently, this vertebrate has also become a model for the investigation of adult neurogenesis and neural regeneration. Here, we summarize the contributions of zebrafish in neural development and adult neurogenesis

Sedation in the intensive care unit with remifentanil/propofol versus midazolam/fentanyl: a randomised, open-label, pharmacoeconomic trial

INTRODUCTION: Remifentanil is an opioid with a unique pharmacokinetic profile. Its organ-independent elimination and short context-sensitive half time of 3 to 4 minutes lead to a highly predictable offset of action. We tested the hypothesis that with an analgesia-based sedation regimen with remifentanil and propofol, patients after cardiac surgery reach predefined criteria for discharge from the intensive care unit (ICU) sooner, resulting in shorter duration of time spent in the ICU, compared to a conventional regimen consisting of midazolam and fentanyl. In addition, the two regimens were compared regarding their costs. METHODS: In this prospective, open-label, randomised, single-centre study, a total of 80 patients (18 to 75 years old), who had undergone cardiac surgery, were postoperatively assigned to one of two treatment regimens for sedation in the ICU for 12 to 72 hours. Patients in the remifentanil/propofol group received remifentanil (6- max. 60 μg kg(-1 )h(-1); dose exceeds recommended labelling). Propofol (0.5 to 4.0 mg kg(-1 )h(-1)) was supplemented only in the case of insufficient sedation at maximal remifentanil dose. Patients in the midazolam/fentanyl group received midazolam (0.02 to 0.2 mg kg(-1 )h(-1)) and fentanyl (1.0 to 7.0 μg kg(-1 )h(-1)). For treatment of pain after extubation, both groups received morphine and/or non-opioid analgesics. RESULTS: The time intervals (mean values ± standard deviation) from arrival at the ICU until extubation (20.7 ± 5.2 hours versus 24.2 h ± 7.0 hours) and from arrival until eligible discharge from the ICU (46.1 ± 22.0 hours versus 62.4 ± 27.2 hours) were significantly (p < 0.05) shorter in the remifentanil/propofol group. Overall costs of the ICU stay per patient were equal (approximately €1,700 on average). CONCLUSION: Compared with midazolam/fentanyl, a remifentanil-based regimen for analgesia and sedation supplemented with propofol significantly reduced the time on mechanical ventilation and allowed earlier discharge from the ICU, at equal overall costs

From top to bottom: Cell polarity in Hedgehog and Wnt trafficking.

This is the final version of the article. Available from the publisher via the DOI in this record.Spatial organization of membrane domains within cells and cells within tissues is key to the development of organisms and the maintenance of adult tissue. Cell polarization is crucial for correct cell-cell signalling, which, in turn, promotes cell differentiation and tissue patterning. However, the mechanisms linking internal cell polarity to intercellular signalling are just beginning to be unravelled. The Hedgehog (Hh) and Wnt pathways are major directors of development and their malfunction can cause severe disorders like cancer. Here we discuss parallel advances into understanding the mechanism of Hedgehog and Wnt signal dissemination and reception. We hypothesize that cell polarization of the signal-sending and signal-receiving cells is crucial for proper signal spreading and activation of the pathway and, thus, fundamental for development of multicellular organisms.SS and LB funding was provided by the University of Exeter, UK (LSI Start-up Grant awarded to SS). ACG and DSH are funded on a Young Investigator Grant (BFU2015-73609-JIN) to ACG from MINECO (Spain). DSH was also funded by a collaboration short-term EMBO fellowship. The authors would like to thank Isabel Guerrero (University of Madrid) for her respective valuable comments that helped improve the quality of the manuscript

Pax6 regulates the formation of the habenular nuclei by controlling the temporospatial expression of Shh in the diencephalon in vertebrates

The aim of this study was to describe epidemiologic characteristics of intestinal parasites in a population in south of Tehran, Iran. A retrospective cross-sectional study of patients with suspicious intestinal parasitic infections referred to the Zakaria Razi Laboratory in Shahre-Ray, southern Tehran, Iran, was conducted from April 21, 2004 to October 20, 2005. All stool samples were examined and socio-demographic informations were retrieved. Of 4,371 referred patients, 466 (239 males and 227 females) were laboratory diagnosed with intestinal parasites, with a period prevalence of 10.7. Blastocystis hominis (B. hominis) and Giardia lamblia (G. lamblia) were the most frequent intestinal parasites. More than half of patients aged � 18 years had a low level of educational attainment (e.g. illiterate, primary school, high school) (170/331, 54.1). Further, majority of patients were homemakers (42.3, 140/331) or workers (28.1, 93/331) employed in various business settings such as food industry and construction. Findings of this study showed that intestinal parasitic infections are still a major public health challenge in Iran that needs to be addressed. We believe that public education, improving sanitation conditions of underdeveloped areas/communities, community involvement, and supporting evidence-based practice/programs are the major keys to success in preventing the spread of intestinal parasitic infections in Iran

Building the gateway to consciousness - about the development of the thalamus

Since years, patterning and function of some brain parts such as the cortex in the forebrain and the optical tectum or cerebellum in the midbrain/hindbrain region are under strong investigation. Interestingly the diencephalon located in the caudal forebrain has been ignored for decades. Consequently, the existing knowledge from the development of this region to function in the mature brain is very fragmented. The central part of the diencephalon is the thalamus. This central relay station plays a crucial role in distributing incoming sensory information to appropriate regions of the cortex. The thalamus develops in the posterior part of the embryonic forebrain, where early cell fate decisions are controlled by local signaling centers. In this Research Topic we discuss recent achievements elucidating thalamic neurogenesis - from neural progenitor cells to highly specialized neurons with cortical target cells in great distance. In parallel, we highlight developmental aspects leading from the early thalamic anlage to the late the organization of the complex relay station of the brain