The cell cycle program of polypeptide labeling in Chlamydomonas reinhardtii

The cell cycle program of polypeptide labeling in syndhronous cultures of wild-type Chlamydomonas reinhardtii was analyzed by pulse-labeling cells with 35SO4 = or [3H]arginine at different cell cycle stages. Nearly 100 labeled membrane and soluble polypeptides were resolved and studied using one-dimensional sodium dodecyl sulfate (SDS)- polyacrylamide gel electrophoresis. The labeling experiments produced the following results. (a) Total 35SO4 = and [3H]arginine incorporation rates varied independently throughout the cell cycle. 35SO4 = incorporation was highest in the mid-light phase, while [3H]arginine incorporation peaked in the dark phase just before cell division. (b) The relative labeling rate for 20 of 100 polypeptides showed significant fluctuations (3-12 fold) during the cell cycle. The remaining polypeptides were labeled at a rate commensurate with total 35SO4 = or [3H]arginine incorporation. The polypeptides that showed significant fluctuations in relative labeling rates served as markers to identify cell cycle stages. (c) The effects of illumination conditions on the apparent cell cycle stage-specific labeling of polypeptides were tested. Shifting light-grown asynchronous cells to the dark had an immediate and pronounced effect on the pattern of polypeptide labeling, but shifting dark-phase syndhronous cells to the light had little effect. The apparent cell cycle variations in the labeling of ribulose 1,5-biphosphate (RUBP)-carboxylase were strongly influenced by illumination effects. (d) Pulse-chase experiments with light-grown asynchronous cells revealed little turnover or inter- conversion of labeled polypeptides within one cell generation, meaning that major polypeptides, whether labeled in a stage-specific manner or not, do not appear transiently in the cell cycle of actively dividing, light-grown cells. The cell cycle program of labeling was used to analyze effects of a temperature-sensitive cycle blocked (cb) mutant. A synchronous culture of ts10001 was shifted to restrictive temperature before its block point to prevent it from dividing. The mutant continued its cell cycle program of polypeptide labeling for over a cell generation, despite its inability to divide

Results from the LSND Neutrino Oscillation Search

The Liquid Scintillator Neutrino Detector (LSND) at the Los Alamos Meson Physics Facility sets bounds on neutrino oscillations in the appearance channel nu_mu_bar --> nu_e_bar by searching for the signature of the reaction nu_e_bar p --> e^+ n: an e$^+$ followed by a 2.2MeV gamma ray from neutron capture. Five e^{+/-} -- gamma coincidences are observed in time with the LAMPF beam, with an estimated background of 6.2 events. The 90\% confidence limits obtained are: Delta (m^2) < 0.07eV^2 for sin^2 (2theta) = 1, and sin^2(2theta) < 6 10^{-3} for Delta (m^2) > 20 eV^2.Comment: 10 pages, uses REVTeX and epsf macro

Ultramafic xenoliths from the Bearpaw Mountains, Montana, USA: evidence for multiple metasomatic events in the lithospheric mantle beneath the Wyoming craton

Ultramafic xenoliths in Eocene minettes of the Bearpaw Mountains volcanic field (Montana, USA), derived from the lower lithosphere of the Wyoming craton, can be divided based on textural criteria into tectonite and cumulate groups. The tectonites consist of strongly depleted spinel lherzolites, harzburgites and dunites. Although their mineralogical compositions are generally similar to those of spinel peridotites in off-craton settings, some contain pyroxenes and spinels that have unusually low Al2O3 contents more akin to those found in cratonic spinel peridotites. Furthermore, the tectonite peridotites have whole-rock major element compositions that tend to be significantly more depleted than non-cratonic mantle spinel peridotites (high MgO, low CaO, Al2O3 and TiO2) and resemble those of cratonic mantle. These compositions could have been generated by up to 30% partial melting of an undepleted mantle source. Petrographic evidence suggests that the mantle beneath the Wyoming craton was re-enriched in three ways: (1) by silicate melts that formed mica websterite and clinopyroxenite veins; (2) by growth of phlogopite from K-rich hydrous fluids; (3) by interaction with aqueous fluids to form orthopyroxene porphyroblasts and orthopyroxenite veins. In contrast to their depleted major element compositions, the tectonite peridotites are mostly light rare earth element (LREE)-enriched and show enrichment in fluid-mobile elements such as Cs, Rb, U and Pb on mantle-normalized diagrams. Lack of enrichment in high field strength elements (HFSE; e.g. Nb, Ta, Zr and Hf) suggests that the tectonite peridotites have been metasomatized by a subduction-related fluid. Clinopyroxenes from the tectonite peridotites have distinct U-shaped REE patterns with strong LREE enrichment. They have 143Nd/144Nd values that range from 0·5121 (close to the host minette values) to 0·5107, similar to those of xenoliths from the nearby Highwood Mountains. Foliated mica websterites also have low 143Nd/144Nd values (0·5113) and extremely high 87Sr/86Sr ratios in their constituent phlogopite, indicating an ancient (probably mid-Proterozoic) enrichment. This enriched mantle lithosphere later contributed to the formation of the high-K Eocene host magmas. The cumulate group ranges from clinopyroxene-rich mica peridotites (including abundant mica wehrlites) to mica clinopyroxenites. Most contain >30% phlogopite. Their mineral compositions are similar to those of phenocrysts in the host minettes. Their whole-rock compositions are generally poorer in MgO but richer in incompatible trace elements than those of the tectonite peridotites. Whole-rock trace element patterns are enriched in large ion lithophile elements (LILE; Rb, Cs, U and Pb) and depleted in HFSE (Nb, Ta Zr and Hf) as in the host minettes, and their Sr–Nd isotopic compositions are also identical to those of the minettes. Their clinopyroxenes are LREE-enriched and formed in equilibrium with a LREE-enriched melt closely resembling the minettes. The cumulates therefore represent a much younger magmatic event, related to crystallization at mantle depths of minette magmas in Eocene times, that caused further metasomatic enrichment of the lithosphere

Real time, Non-Intrusive Instrumentation & Monitoring of Standards-based Event-based Middleware

poster abstractStandards-based middleware, such as the Common Object Request Broker Architecture (CORBA) Component Model and the Data Distribution Service, support event-based services for decoupled, asynchronous messaging between software components in a distributed system. The messaging models use the publisher-subscriber paradigm where one or more subscribers can subscribe to events from one or more publishers. The advantage of this paradigm is neither the publisher nor subscriber needs to be aware of the other. Instead, either entity is only concerned with the publication or receipt of an event. A critical aspect of these systems, however, is their instrumentation for analysis purposes, like monitoring its performance, state, and behavior to ensure the system is executing as expected. Traditionally, instrumenting such systems relied on intrusive instrumentation approaches, where developer inserted code snippets into the source code to collect the information needed. This means that developers must understand the original code, run the risk of inserting malicious code, and intermix code related to instrumentation with the normal business logic. Moreover, as the normal business logic evolves, the instrumentation code must also evolve. This can become a burden on developers until the business logic become less volatile. To overcome this complexity, we present Dynamic Event Monitor, a tool that can non-intrusively instrument and monitor events in a large scale distributed system at run time, using dynamic binary instrumentation. It operates in contexts without any a priori knowledge of the concrete events in the system, or how the system is composed. We have applied Dynamic Event Monitor to applications implemented in CORBA. Our results show that once the application is completely instrumented, the performance impact of actually monitoring events is minimal. For the applications we have tested, the instrumentation time is about 30-45 seconds and the time for real-time monitoring of events is about 2 milliseconds

A Digital Neuromorphic Architecture Efficiently Facilitating Complex Synaptic Response Functions Applied to Liquid State Machines

Information in neural networks is represented as weighted connections, or synapses, between neurons. This poses a problem as the primary computational bottleneck for neural networks is the vector-matrix multiply when inputs are multiplied by the neural network weights. Conventional processing architectures are not well suited for simulating neural networks, often requiring large amounts of energy and time. Additionally, synapses in biological neural networks are not binary connections, but exhibit a nonlinear response function as neurotransmitters are emitted and diffuse between neurons. Inspired by neuroscience principles, we present a digital neuromorphic architecture, the Spiking Temporal Processing Unit (STPU), capable of modeling arbitrary complex synaptic response functions without requiring additional hardware components. We consider the paradigm of spiking neurons with temporally coded information as opposed to non-spiking rate coded neurons used in most neural networks. In this paradigm we examine liquid state machines applied to speech recognition and show how a liquid state machine with temporal dynamics maps onto the STPU-demonstrating the flexibility and efficiency of the STPU for instantiating neural algorithms.Comment: 8 pages, 4 Figures, Preprint of 2017 IJCN

Gender, Sexual Orientation, and Truth-of-Consensus in Studies of Physical Attractiveness

Truth-of-consensus methodology presently holds that sex differences in perceptions of physical attractiveness are negligible and may be routinely ignored during prescaling. No determination has been made in the literature of the effects of sexual orientation on this perceptual process. The data presented herein suggest that while sex and sexual orientation of judge are largely irrelevant to prescaling of female stimuli, these variables are important when judging male stimuli. In particular, male homosexuals and male heterosexuals differ significantly in ranking male facial photographs. Thus, experimenters wishing to treat attractiveness levels as known quantities should control for this difference, especially when using a small number of judges for prescaling

Using Machine Learning Techniques to Classify and Predict Static Code Analysis Tool Warnings

This paper discusses our work on using software engineering metrics (i.e., source code metrics) to classify an error message generated by a Static Code Analysis (SCA) tool as a true-positive, false-positive, or false-negative. Specifically, we compare the performance of Support Vector Machine (SVM), K-Nearest Neighbor (KNN), Random Forests, and Repeated Incremental Pruning to Produce Error Reduction (RIPPER) over eight datasets. The performance of the techniques is assessed by computing the F-measure metric, which is defined as the weighted harmonic mean of the precision and recall of the predicted model. The overall results of the study show that the F-measure value of the predicted model, which is generated using Random Forests technique, ranges from 83% to 98%. Additionally, the Random Forests technique outperforms the other techniques. Lastly, our results indicate that the complexity and coupling metrics have the most impact on whether a SCA tool with generate a false-positive warning or not

The Lennard-Jones-Devonshire cell model revisited

We reanalyse the cell theory of Lennard-Jones and Devonshire and find that in addition to the critical point originally reported for the 12-6 potential (and widely quoted in standard textbooks), the model exhibits a further critical point. We show that the latter is actually a more appropriate candidate for liquid-gas criticality than the original critical point.Comment: 5 pages, 3 figures, submitted to Mol. Phy

Global perspectives and translations of consuming clothing waste in the present

The mass consumption of clothing has resulted in collection charities such as Oxfam exporting unwanted second hand clothing to markets in the Sub-Saharan region. This is a trade that is seen as supporting sustainable solutions to unwanted clothing but offers ‘both opportunity’ and ‘danger’ to local communities (Haggblade, 2007). The research explores the second hand clothing trade in Ghana, which evidences this danger and challenges the notion of opportunity. The second hand clothing market whilst benefitting local communities in Africa has also impacted upon local textile production. From our conversations around these issues, a collaborative project idea emerged entitled ‘Return to Sender’. The project aims to highlight and challenge the effects of the second hand clothing market upon local heritage in Africa. A shared perspective through global design stories can encourage designers to understand the consequences of design but at the time same enable them to have the power to impact and drive change of consumer habits. The current and future perspectives of purchasing clothing and re-use is explored, regarding how this could then influence and change the global second hand clothing markets. This paper also explores the potential of sustainable outcomes through focusing design in the present, rather than the future. In order to understand a global world we need to see the world as it is to solve the problems and in turn prevent problems in the future. We need an approach that is not engrained into a system but something that promotes creativity and openness to change

Glimmerglass Volume 14 Number 03 (1954)

Official Student Newspaper Issue is 6 pages long