561 research outputs found
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
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
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
CRISPR/Cas9 and genetic screens in malaria parasites : small genomes, big impact
The ∼30 Mb genomes of the Plasmodium parasites that cause malaria each encode ∼5000 genes, but the functions of the majority remain unknown. This is due to a paucity of functional annotation from sequence homology, which is compounded by low genetic tractability compared with many model organisms. In recent years technical breakthroughs have made forward and reverse genome-scale screens in Plasmodium possible. Furthermore, the adaptation of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-Associated protein 9 (CRISPR/Cas9) technology has dramatically improved gene editing efficiency at the single gene level. Here, we review the arrival of genetic screens in malaria parasites to analyse parasite gene function at a genome-scale and their impact on understanding parasite biology. CRISPR/Cas9 screens, which have revolutionised human and model organism research, have not yet been implemented in malaria parasites due to the need for more complex CRISPR/Cas9 gene targeting vector libraries. We therefore introduce the reader to CRISPR-based screens in the related apicomplexan Toxoplasma gondii and discuss how these approaches could be adapted to develop CRISPR/Cas9 based genome-scale genetic screens in malaria parasites. Moreover, since more than half of Plasmodium genes are required for normal asexual blood-stage reproduction, and cannot be targeted using knockout methods, we discuss how CRISPR/Cas9 could be used to scale up conditional gene knockdown approaches to systematically assign function to essential genes.Instituto de BiotecnologíaFil: Ishizaki, Takahiro. Umeå University. Department of Molecular Biology; SueciaFil: Ishizaki, Takahiro. The Laboratory for Molecular Infection Medicine Sweden (MIMS); SueciaFil: Hernandez, Sophia. Umeå University. Department of Molecular Biology; SueciaFil: Hernandez, Sophia. The Laboratory for Molecular Infection Medicine Sweden (MIMS); SueciaFil: Paoletta, Martina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; ArgentinaFil: Paoletta, Martina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Paoletta, Martina. Umeå University. Department of Molecular Biology; SueciaFil: Paoletta, Martina. The Laboratory for Molecular Infection Medicine Sweden (MIMS); SueciaFil: Sanderson, Theo. Francis Crick Institute; Reino UnidoFil: Bushell, Ellen S. C. Umeå University. Department of Molecular Biology; SueciaFil: Bushell, Ellen S. C. The Laboratory for Molecular Infection Medicine Sweden (MIMS); Sueci
A gastrin transcript expressed in gastrointestinal cancer cells contains an internal ribosome entry site
As the hormone gastrin promotes gastrointestinal (GI) cancer progression by triggering survival pathways, regulation of gastrin expression at the translational level was explored. Sequence within the 5′ untranslated region of a gastrin transcript expressed in GI cancer cells was investigated, then cloned into a bicistronic vector upstream of firefly luciferase and transfected into a series of GI cancer cell lines. Firefly luciferase activity was measured relative to that of a cap-dependent Renilla luciferase. A gastrin transcript that was different from that described in Ensembl was expressed in GI cancer cells. Its transcription appears to be initiated within the region designated as the gene's first intron. In GI cancer cells transfected with the bicistronic construct, firefly luciferase activity increased 8–15-fold compared with the control vector, and there was a further induction of the signal (up to 25-fold) following exposure of the cells to genotoxic stress or hypoxia, suggesting that the sequence acts as an internal ribosome entry site. These data suggest that the gastrin transcript within GI cancer cells contains an internal ribosome entry site that may allow continued expression of gastrin peptides when normal translational mechanisms are inactive, such as in hypoxia, thereby promoting cancer cell survival
“I just want them to feel safe and enjoy PE”: experiences of teaching gender questioning students in sport, physical activity and dance
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
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