Effect of Tetracycline on Late-stage African trypanosomiasis in Rats

The effect of tetracycline on late stage African trypanosomiasis was examined in an in vivo experiment using rats infected with Trypanosoma brucei brucei. Infected rats were treated on the 5th day of infection with 10mg/kg and 20mg/kg rat weight of tetracycline and tetracycline hydrochloride. Tetracycline at 10mg/kg extended the life-span of infected rats from 6 days to 11 days, but with 20mg/kg the rats died on day 6. Tetracycline–HCl at 10 and 20mg/kg extended the lifespan to 9 and 12 days respectively. The trypanocidal effect of tetracycline on late stage trypanosomiasis is probably due to its ability to penetrate the blood brain barrier and its probable role in inhibiting ribonucleotide reductase through iron chelation. We suggest that tetracycline-HCl and low concentrations of tetracycline can be used in the clinical management of African Trypanosomiasis.Key words: African trypanosomiasis, Tetracycline, Late Stag

Impact of seeding rate on weed-free field peas

Non-Peer ReviewedThe impact of seed placement and seeding rate on crop yield is not clearly understood for field pea (Pisum sativum L.). A field experiment was conducted at seven sites across Saskatchewan in 2001 to examine the influence of a wide range of seeding rates (20, 30, 40, 50, 60, 70, 80, 90, 100, and 120 target plants m-2). Yield component compensation occurred where increased plant density from higher seeding rates reduced seed weight. Seed yield benefits were small at seeding rates greater than 50 target plants m-2. There was a tendency for lower yields with seeding rates less than 50, especially at sites with higher yield potential. Yields of field peas grown under relatively weed-free conditions should be optimized with a seeding rate of 50 to 75 seeds m-2

Concern for Information Privacy and Online Consumer Purchasing

Although electronic commerce experts often cite privacy concerns as barriers to consumer electronic commerce, there is a lack of understanding about how these privacy concerns impact consumers\u27 willingness to conduct transactions online. Therefore, the goal of this study is to extend previous models of e-commerce adoption by specifically assessing the impact that consumers\u27 concerns for information privacy (CFIP) have on their willingness to engage in online transactions. To investigate this, we conducted surveys focusing on consumers\u27 willingness to transact with a well-known and less well-known Web merchant. Results of the study indicate that concern for information privacy affects risk perceptions, trust, and willingness to transact for a well-known merchant, but not for a less well-known merchant. In addition, the results indicate that merchant familiarity does not moderate the relationship between CFIP and risk perceptions or CFIP and trust. Implications for researchers and practitioners are discussed

The Applications and Challenges of the Development of In Vitro Tumor Microenvironment Chips

The tumor microenvironment (TME) plays a critical, yet mechanistically elusive role in tumor development and progression, as well as drug resistance. To better understand the pathophysiology of the complex TME, a reductionist approach has been employed to create in vitro microfluidic models called “tumor chips”. Herein, we review the fabrication processes, applications, and limitations of the tumor chips currently under development for use in cancer research. Tumor chips afford capabilities for real-time observation, precise control of microenvironment factors (e.g. stromal and cellular components), and application of physiologically relevant fluid shear stresses and perturbations. Applications for tumor chips include drug screening and toxicity testing, assessment of drug delivery modalities, and studies of transport and interactions of immune cells and circulating tumor cells with primary tumor sites. The utility of tumor chips is currently limited by the ability to recapitulate the nuances of tumor physiology, including extracellular matrix composition and stiffness, heterogeneity of cellular components, hypoxic gradients, and inclusion of blood cells and the coagulome in the blood microenvironment. Overcoming these challenges and improving the physiological relevance of in vitro tumor models could provide powerful testing platforms in cancer research and decrease the need for animal and clinical studies

Bubbling Orientifolds

We investigate a class of 1/2-BPS bubbling geometries associated to orientifolds of type IIB string theory and thereby to excited states of the SO(N)/Sp(N) N=4 supersymmetric Yang-Mills theory. The geometries are in correspondence with free fermions moving in a harmonic oscillator potential on the half-line. Branes wrapped on torsion cycles of these geometries are identified in the fermi fluid description. Besides being of intrinsic interest, these solutions may also occur as local geometries in flux compactifications where orientifold planes are present to ensure global charge cancellation. We comment on the extension of this procedure to M-theory orientifolds.Comment: 25 pages, 11 figures. v2: few references adde

Dynamic correlations of the Coulomb Luttinger liquid

The dynamic density response function, form-factor, and spectral function of a Luttinger liquid with Coulomb electron-electron interaction are studied with the emphasis on the short-range electron correlations. The Coulomb interaction changes dramatically the density response function as compared to the case of the short-ranged interaction. The form of the density response function is smoothing with time, and the oscillatory structure appears. However, the spectral functions remain qualitatively the same. The dynamic form-factor contains the $\delta$-peak in the long-wave region, corresponding to one-boson excitations. Besides, the multi-boson-excitations band exists in the wave-number region near to $2k_F$. The dynamic form-factor diverges at the edges of this band, while the dielectric function goes to zero there, which indicates the appearance of a soft mode. We develop a method to analyze the asymptotics of the spectral functions near to the edges of the multi-boson-excitations band.Comment: 11 pages, 3 figures, submitted to PR

Observed differences in upper extremity forces, muscle efforts, postures, velocities, and accelerations across computer activities in a field study of office workers

This study, a part of the PRedicting Occupational biomechanics in OFfice workers (PROOF) study, investigated whether there are differences in field-measured forces, muscle efforts, postures, velocities and accelerations across computer activities. These parameters were measured continuously for 120 office workers performing their own work for two hours each. There were differences in nearly all forces, muscle efforts, postures, velocities and accelerations across keyboard, mouse and idle activities. Keyboard activities showed a 50% increase in the median right trapezius muscle effort when compared to mouse activities. Median shoulder rotation changed from 25 degrees internal rotation during keyboard use to 15 degrees external rotation during mouse use. Only keyboard use was associated with median ulnar deviations greater than 5 degrees. Idle activities led to the greatest variability observed in all muscle efforts and postures measured. In future studies, measurements of computer activities could be used to provide information on the physical exposures experienced during computer use. Practitioner Summary: Computer users may develop musculoskeletal disorders due to their force, muscle effort, posture and wrist velocity and acceleration exposures during computer use. We report that many physical exposures are different across computer activities. This information may be used to estimate physical exposures based on patterns of computer activities over time. © 2012 Copyright Taylor and Francis Group, LLC