835 research outputs found
Perfusion based microfluidic system for pharmacological profiling of neuronal networks
This work presents the integration of a semi-automated microfluidic platform that utilizes calcium imaging to enable the pharmacological characterization of functionally connected, but environmentally isolated neuronal networks. This approach allows, for the first time, to assess the cause-effect relationship of neuronal communication following drug application, thus allowing the pharmacological characterisation of novel drugs proposed to influence communication between neuronal networks
Normal Cones and Thompson Metric
The aim of this paper is to study the basic properties of the Thompson metric
in the general case of a real linear space ordered by a cone . We
show that has monotonicity properties which make it compatible with the
linear structure. We also prove several convexity properties of and some
results concerning the topology of , including a brief study of the
-convergence of monotone sequences. It is shown most of the results are
true without any assumption of an Archimedean-type property for . One
considers various completeness properties and one studies the relations between
them. Since is defined in the context of a generic ordered linear space,
with no need of an underlying topological structure, one expects to express its
completeness in terms of properties of the ordering, with respect to the linear
structure. This is done in this paper and, to the best of our knowledge, this
has not been done yet. The Thompson metric and order-unit (semi)norms
are strongly related and share important properties, as both are
defined in terms of the ordered linear structure. Although and
are only topological (and not metrical) equivalent on , we
prove that the completeness is a common feature. One proves the completeness of
the Thompson metric on a sequentially complete normal cone in a locally convex
space. At the end of the paper, it is shown that, in the case of a Banach
space, the normality of the cone is also necessary for the completeness of the
Thompson metric.Comment: 36 page
Maternal Obesity in Pregnancy Developmentally Programs Adipose Tissue Inflammation in Young, Lean Male Mice Offspring.
Obesity during pregnancy has a long-term effect on the health of the offspring including risk of developing the metabolic syndrome. Using a mouse model of maternal diet-induced obesity, we employed a genome-wide approach to investigate the microRNA (miRNA) and miRNA transcription profile in adipose tissue to understand mechanisms through which this occurs. Male offspring of diet-induced obese mothers, fed a control diet from weaning, showed no differences in body weight or adiposity at 8 weeks of age. However, offspring from the obese dams had up-regulated cytokine (Tnfα; P < .05) and chemokine (Ccl2 and Ccl7; P < .05) signaling in their adipose tissue. This was accompanied by reduced expression of miR-706, which we showed can directly regulate translation of the inflammatory proteins IL-33 (41% up-regulated; P < .05) and calcium/calmodulin-dependent protein kinase 1D (30% up-regulated; P < .01). We conclude that exposure to obesity during development primes an inflammatory environment in adipose tissue that is independent of offspring adiposity. Programming of adipose tissue miRNAs that regulate expression of inflammatory signaling molecules may be a contributing mechanism.This work was supported by Funding sources: National Council for the Improvement of Higher Education (CAPES - Brazil - BEX 10 594/13–2); National Counsel of Technological and Scientific Development (CNPq – Brazil – PDE/204416/ 2014–0); Medical Research Council (MC UU 12012/4 and MC UU12012/5), BBSRC (BB/M001636/1) and the Wellcome Trust (089940/Z/09/Z).This is the final version of the article. It first appeared from the Endocrine Society via http://dx.doi.org/10.1210/en.2016-131
Interaction of eukaryotic translation initiation factor 4G with the nuclear cap-binding complex provides a link between nuclear and cytoplasmic functions of the m7 guanosine cap
In eukaryotes the majority of mRNAs have an m7G cap that is added cotranscriptionally and that plays an important role in many aspects of mRNA metabolism. The nuclear cap-binding complex (CBC; consisting of CBP20 and CBP80) mediates the stimulatory functions of the cap in pre-mRNA splicing, 3' end formation, and U snRNA export. As little is known about how nuclear CBC mediates the effects of the cap in higher eukaryotes, we have characterized proteins that interact with CBC in HeLa cell nuclear extracts as potential mediators of its function. Using cross-linking and coimmunoprecipitation, we show that eukaryotic translation initiation factor 4G (eIF4G), in addition to its function in the cytoplasm, is a nuclear CBC-interacting protein. We demonstrate that eIF4G interacts with CBC in vitro and that, in addition to its cytoplasmic localization, there is a significant nuclear pool of eIF4G in mammalian cells in vivo. Immunoprecipitation experiments suggest that, in contrast to the cytoplasmic pool, much of the nuclear eIF4G is not associated with eIF4E (translation cap binding protein of eIF4F) but is associated with CBC. While eIF4G stably associates with spliceosomes in vitro and shows close association with spliceosomal snRNPs and splicing factors in vivo, depletion studies show that it does not participate directly in the splicing reaction. Taken together the data indicate that nuclear eIF4G may be recruited to pre-mRNAs via its interaction with CBC and accompanies the mRNA to the cytoplasm, facilitating the switching of CBC for eIF4F. This may provide a mechanism to couple nuclear and cytoplasmic functions of the mRNA cap structure
Can Long-Term Training in Highly Focused Forms of Observation Potientially Influence Performace in Terms of the Observer Model In Physics? Consideration of Adepts of Observational Meditation Practice
This paper presents developments in a published yet still little known model of how intensively trained individuals - adepts or virtuosi of special meditational techniques - appear to be potentially capable of radically enhancing their sensory perceptual capacities to the point of, for example, directly perceiving light at the scale of single photons, at the quantum mechanical limit of its detectability. This is a working model which is based also on little-known work of leading physicists and biophysicists from Princeton, Stanford, Berkeley and other institutions
A Description of an Improved Homodyne Laser Interferometer
First appearing on the commercial market in the mid 1980’s, diode-pumped, continuous-wave (cw) Nd:YAG lasers have more recently been used to obtain visible output, by the incorporation of frequency doubling optics in the laser cavity.The laser diode pumping of a Nd:YAG laser rod is selective and highly efficient, resulting in compact, high power, spatial mode lasers. Frequency-doubling processes are non-linear and lead to doubling TEM00 only of the high energy fundamental temporal mode, resulting in operation of the 532 nm laser in a single spatial and single longitudinal mode. The technology is rapidly advancing, and green lasers with energies of up to 1W could soon be available. The beam properties of the lasers described above are highly desirable in the field of interferometry, where such lasers are now in direct competition with the much larger Argon lasers, which have already been employed in high power interferometric systems. We describe here the performance of a modified Michelson interferometer [1–4], built to incorporate a 90 mW ADLAS 300 diode-pumped Nd:YAG laser. In previous versions of the Michelson interferometer, we have used HeNe lasers with a few milliwatts output, requiring mirror-quality surfaces on our samples. A 90 mW laser power enables us to make displacement measurements on metal surfaces with little or no preparation. The laser could also, of course, be used in other, more elaborate interferometer types, such as the confocal Fabry-Perot, which are better suited to industrial environments
Processes Controlling Tropical Tropopause Temperature and Stratospheric Water Vapor in Climate Models
A warm bias in tropical tropopause temperature is found in the Met Office Unified Model (MetUM), in common with most models from phase 5 of CMIP (CMIP5). Key dynamical, microphysical, and radiative processes influencing the tropical tropopause temperature and lower-stratospheric water vapor concentrations in climate models are investigated using the MetUM. A series of sensitivity experiments are run to separate the effects of vertical advection, ice optical and microphysical properties, convection, cirrus clouds, and atmospheric composition on simulated tropopause temperature and lower-stratospheric water vapor concentrations in the tropics. The numerical accuracy of the vertical advection, determined in the MetUM by the choice of interpolation and conservation schemes used, is found to be particularly important. Microphysical and radiative processes are found to influence stratospheric water vapor both through modifying the tropical tropopause temperature and through modifying upper-tropospheric water vapor concentrations, allowing more water vapor to be advected into the stratosphere. The representation of any of the processes discussed can act to significantly reduce biases in tropical tropopause temperature and stratospheric water vapor in a physical way, thereby improving climate simulations
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The Met Office Unified Model Global Atmosphere 7.0/7.1 and JULES Global Land 7.0 configurations
We describe Global Atmosphere 7.0 and GlobalLand 7.0 (GA7.0/GL7.0), the latest science configurations of the Met Office Unified Model (UM) and the Joint UK Land Environment Simulator (JULES) land surface model developed for use across weather and climate timescales. GA7.0 and GL7.0 include incremental developments and targeted improvements that, between them, address four critical errors identified in previous configurations: excessive precipitation biases over India, warm and moist biases in the tropical tropopause layer (TTL), a source of energy non-conservation in the advection scheme and excessive surface radiation biases over the Southern Ocean. They also include two new parametrisations, namely the UK Chemistry and Aerosol(UKCA) GLOMAP-mode (Global Model of Aerosol Processes) aerosol scheme and the JULES multi-layer snow scheme, which improve the fidelity of the simulation and were required for inclusion in the Global Atmosphere/Global Land configurations ahead of the 6th Coupled Model Inter-comparison Project (CMIP6).In addition, we describe the GA7.1 branch configuration, which reduces an overly negative anthropogenic aerosol effective radiative forcing (ERF) in GA7.0 whilst maintaining the quality of simulations of the present-day climate. GA7.1/GL7.0 will form the physical atmosphere/land component in the HadGEM3–GC3.1 and UKESM1 climate model submissions to the CMIP6
Plasmodium genes responsible for oocyst development and interaction with its Anopheline vector
The transmission of the malaria parasite Plasmodium is governed by a complex
developmental cycle. This PhD thesis describes the transcriptional profiling of the
rodent malaria parasite Plasmodium berghei developmental migration through its A.
gambiae vector. The study was conducted in vivo, using a near complete P. berghei
genome microarray platform. Emphasis was placed on the oocyst stage, as little is
known about the genes implicated in the ookinete to oocyst transition, and oocyst
maturation. The data presented here provide novel transcriptional information about
Plasmodium transmission. The analysis revealed a large shift in gene utilisation as the
parasite makes its transition from the motile ookinete to the sessile oocyst.
Furthermore, this work has shown that different sets of co-regulated genes are
important for early and late oocyst development.
In addition, this PhD thesis outlines the characterisation of a novel Plasmodium
formin-like protein essential for rodent malaria transmission named the male inherited
sporulation factor important for transmission (misfit). MISFIT is expressed in the
early mosquito stages, where the protein localises to the parasite nucleus. Misfit
exhibits an absolute requirement for paternal inheritance, which is in accordance with
an observed male-biased expression pattern. pbmisfitΔ ookinetes display significant
ultrastructural and gene expression defects and fail to complete zygotic meiosis.
However, pbmisfitΔ ookinetes retain functionality and can successfully cross the
midgut epithelial barrier. In contrast, mosquito infections with pbmisfitΔ resulted in an
arrest immediately upon ookinete-oocyst transformation, where defective oocysts fail
to sporulate. An essential role in chromosome segregation during mitosis / meiosis is
postulated for MISFIT. In conclusion, the work presented in this thesis has established
the ookinete-oocyst transition as a major cell cycle check point during malaria
transmission and identified misfit as the first male inherited Plasmodium gene known
to affect development post-fertilisation
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