Generation of a sheared plasma rotation by emission, propagation, and absorption of drift wave packets

Collisional electron drift wave turbulence generates drift wave packet structures with density and vorticity fluctuations in the central plasma pressure gradient region of a linear plasma device. Tracking these packets reveals that they follow an outward directed spiral-shaped trajectory in the (r,θ) plane, are azimuthally stretched, and develop anisotropy as they approach an axisymmetric, radially sheared azimuthal flow located at the plasma boundary. Nonlinear energy transfer measurements and time-delay analysis confirm that structure absorption amplifies the sheared flow. Similar mechanisms likely operate at the edge of confined toroidal plasmas and should lead to the amplification of sheared flows at the boundary of these devices as well.

Comparing normal and torn rotator cuff tendons using dynamic shear analysis

This study reports the application of a novel method for quantitatively determining differences in the mechanical properties of healthy and torn rotator cuff tissues. In order to overcome problems of stress risers at the grip-tendon interface that can obscure mechanical measurements of small tendons, we conducted our investigation using dynamic shear analysis.

Rotator cuff tendon specimens were obtained from 100 patients during shoulder surgery. They included 82 differently sized tears and 18 matched controls. We subjected biopsy samples of 3 mm in diameter to oscillatory deformation under compression using dynamic shear analysis. The storage modulus (G’) was calculated as an indicator of mechanical integrity.

Normal tendons had a significantly higher storage modulus than torn tendons, indicating that torn tendons are mechanically weaker than normal tendons (p = 0.003). Normal tendons had a significantly higher mean shear modulus than tendons with massive tears (p < 0.01).

Dynamic shear analysis allows the determination of shear mechanical properties of small tissue specimens obtained intra-operatively that could not be studied by conventional methods of tensile testing. These methods could be employed to investigate other musculoskeletal tissues. This pilot study provides some insight into mechanisms that might contribute to the failure of repair surgery, and with future application could help direct the most appropriate treatment for specific rotator cuff tears.

Epitheliocystis in Atlantic salmon, Salmo salar L., farmed in fresh water in Ireland is associated with 'Candidatus Clavochlamydia salmonicola' infection

Intracellular inclusions containing chlamydia-like organisms are frequently observed in the gill epithelial cells of Atlantic salmon, Salmo salar L., cultured in fresh water in Ireland. In this study, the causative agent was identified in four separate freshwater sites, using 16s rRNA sequencing, as 'Candidatus Clavochlamydia salmonicola'. Histopathology and real-time (RT) PCR were used to further assess infections. The prevalence of infection ranged from 75-100% between sites and infection intensity was highly variable. No significant lesions were associated with these infections. As a diagnostic tool, RT-PCR proved marginally more sensitive than histopathology. The fate of 'Candidatus Clavochlamydia salmonicola' in Atlantic salmon post-seawater transfer was investigated in a 12-week marine longitudinal study. Both RT-PCR and histopathological examination indicate that the organism disappears from the gills 4-6 weeks post-transfer.

Intrinsic rotation from a residual stress at the boundary of a cylindrical laboratory plasma

An azimuthally symmetric radially sheared azimuthal flow is driven by a nondiffusive, or residual, turbulent stress localized to a narrow annular region at the boundary of a cylindrical magnetized helicon plasma device. A no-slip condition, imposed by ion-neutral flow damping outside the annular region, combined with a diffusive stress arising from turbulent and collisional viscous damping in the central plasma region, leads to net plasma rotation in the absence of momentum input.

Beyond NOTES: randomized controlled study of different methods of flexible endoscopic hemostasis of artificially induced hemorrhage, via NOTES access to the peritoneal cavity

BACKGROUND AND STUDY AIM

Significant hemorrhage is a likely complication during natural orifice transluminal endoscopic surgery (NOTES) procedures. We tested three different prototype devices (involving endoscopic suturing, monopolar forceps, and forced argon plasma coagulation [FAPC]) for treatment of acute bleeding in a survival animal model.

METHOD

Using transgastric access (TGA) or transvaginal access (TVA), the endoscope was introduced into the peritoneal cavity and the first side-branch of the gastroepiploic artery (1aGE) was cut before the different hemostatic methods were applied.

RESULTS

Sutures could not be placed quickly enough before vision was inhibited. With monopolar forceps via TGA, the time to control bleeding was 10 - 140 s (mean 58 +/- 41 s) and with TVA it was 25 - 115 s (mean 57 +/- 26 s) (P = 0.54). It was not possible to stop the bleeding in 4/6 animals with TGA access and in 3/6 with TVA, and FAPC was needed to entirely stop it, taking a further 10 - 280 s (TGA mean 126 +/- 90 s, 34 - 242 s; TVA mean 152 +/- 61 s; P = 0.42). Using FAPC with TGA took 4 - 72 s (mean 28 +/- 20 s) to stop the bleeding, and 16 - 41 s (mean 24 +/- 9.4 s) with TVA ( P = 0.64). As the FAPC technique was relatively so much better, additional treatment of bleeding from the main gastroepiploic artery (aGe) was added in four cases for each method of access; this was successful but took significantly longer, with TGA at 10 - 260 s and with TVA at 30 - 172 s (means 98 +/- 82, 117 +/- 54 s, respectively; not significant).

CONCLUSION

Regarding the three methods tested, the new prototype FAPC device allowed hemostasis of notable bleeding from a major vessel even more quickly than forceps coagulation of a bleeding side branch. More studies are needed to further explore this potentially very valuable tool.

A correlation electron cyclotron emission diagnostic and the importance of multifield fluctuation measurements for testing nonlinear gyrokinetic turbulence simulations

A correlation electron cyclotron emission (CECE) diagnostic has been used to measure local, turbulent fluctuations of the electron temperature in the core of DIII-D plasmas. This paper describes the hardware and testing of the CECE diagnostic and highlights the importance of measurements of multifield fluctuation profiles for the testing and validation of nonlinear gyrokinetic codes. The process of testing and validating such codes is critical for extrapolation to next-step fusion devices. For the first time, the radial profiles of electron temperature and density fluctuations are compared to nonlinear gyrokinetic simulations. The CECE diagnostic at DIII-D uses correlation radiometry to measure the rms amplitude and spectrum of the electron temperature fluctuations. Gaussian optics are used to produce a poloidal spot size with w(o) approximately 1.75 cm in the plasma. The intermediate frequency filters and the natural linewidth of the EC emission determine the radial resolution of the CECE diagnostic, which can be less than 1 cm. Wavenumbers resolved by the CECE diagnostic are k(theta) < or = 1.8 cm(-1) and k(r) < or = 4 cm(-1), relevant for studies of long-wavelength turbulence associated with the trapped electron mode and the ion temperature gradient mode. In neutral beam heated L-mode plasmas, core electron temperature fluctuations in the region 0.5 < r/a < 0.9, increase with radius from approximately 0.5% to approximately 2%, similar to density fluctuations that are measured simultaneously with beam emission spectroscopy. After incorporating "synthetic diagnostics" to effectively filter the code output, the simulations reproduce the characteristics of the turbulence and transport at one radial location r/a = 0.5, but not at a second location, r/a = 0.75. These results illustrate that measurements of the profiles of multiple fluctuating fields can provide a significant constraint on the turbulence models employed by the code.

Important research questions in allergy and related diseases: nonallergic rhinitis: a GA2LEN paper

Nonallergic rhinitis (NAR) can be defined as a chronic nasal inflammation which is not caused by systemic IgE-dependent mechanisms. It is common and probably affects far more than 200 million people worldwide. Both children and adults are affected. However, its exact prevalence is unknown and its phenotypes need to be evaluated using appropriate methods to better understand its pathophysiology, diagnosis and management. It is important to differentiate between infectious rhinitis, allergic/NAR and chronic rhinosinusitis, as management differs for each of these cases. Characterization of the phenotype, mechanisms and management of NAR represents one of the major unmet needs in allergic and nonallergic diseases. Studies on children and adults are required in order to appreciate the prevalence, phenotype, severity and co-morbidities of NAR. These studies should compare allergic and NAR and consider different age group populations including elderly subjects. Mechanistic studies should be carried out to better understand the disease(s) and risk factors and to guide towards an improved diagnosis and therapy. These studies need to take the heterogeneity of NAR into account. It is likely that neuronal mechanisms, T cells, innate immunity and possibly auto-immune responses all play a role in NAR and may also contribute to the symptoms of allergic rhinitis.

Comparing the rheology of native spider and silkworm spinning dope

Silk production has evolved to be energetically efficient and functionally optimized, yielding a material that can outperform most industrial fibres, particularly in toughness. Spider silk has hitherto defied all attempts at reproduction, despite advances in our understanding of the molecular mechanisms behind its superb mechanical properties. Spun fibres, natural and man-made, rely on the extrusion process to facilitate molecular orientation and bonding. Hence a full understanding of the flow characteristics of native spinning feedstock (dope) will be essential to translate natural spinning to artificial silk production. Here we show remarkable similarity between the rheologies for native spider-dragline and silkworm-cocoon silk, despite their independent evolution and substantial differences in protein structure. Surprisingly, both dopes behave like typical polymer melts. This observation opens the door to using polymer theory to clarify our general understanding of natural silks, despite the many specializations found in different animal species.

Observation of turbulent-driven shear flow in a cylindrical laboratory plasma device

An azimuthally symmetric radially sheared plasma fluid flow is observed to spontaneously form in a cylindrical magnetized helicon plasma device with no external sources of momentum input. A turbulent momentum conservation analysis shows that this shear flow is sustained by the Reynolds stress generated by collisional drift turbulence in the device. The results provide direct experimental support for the basic theoretical picture of drift-wave-shear-flow interactions.

Collisional damping of ETG-mode-driven zonal flows

We study collisional damping of electron zonal flows in toroidal electron temperature gradient (ETG) turbulence due to the friction between trapped and untrapped electrons. With the assumption of adiabatic ions, the collisional damping is shown to occur on fast time scales approximately 0.24epsilon(1/2)tau(e). The comparison with the growth rate of electron zonal flows indicates that the shearing by electron zonal flows is unlikely to be a robust mechanism for regulating ETG turbulence. This finding vitiates the claims of several simulation studies that have ignored the effects of collisional damping of electron zonal flows and offers a possible partial explanation of the high levels of electron thermal transport observed in the National Spherical Torus Experiment.

Why not natural death?

Alzheimer’s disease (AD) is a devastating and unforgiving disease that steals our loved ones away long before the physical body declines toward death. It robs them of their independence, their history with family and moves them into a type of existence that we can only hope is peaceful, if not content.

Increased nonlinear coupling between turbulence and low-frequency fluctuations at the L-H transition

The nonlinear coupling between small scale high-frequency turbulence and larger scale lower-frequency fluctuations increases transiently in transitions to improved confinement in the DIII-D tokamak. This increase starts before the rapid turbulence suppression and E x B shear-flow development in the region that becomes the H-mode transport barrier/shear flow region. After the transition, the coupling returns to L-mode levels. These results are consistent with expectations for spontaneous transitions to improved confinement triggered by a turbulence-driven sheared flow.

Expression of the human erythrocyte glucose transporter Glut-1 in areas of sclerotic collagen in necrobiosis lipoidica

BACKGROUND

Glut-1 is the human erythrocyte glucose transporter which mediates facilitative transport of glucose across epithelial and endothelial barrier tissues. A primary abnormality in glucose transport and Glut-1 cell-surface content has been observed in fibroblasts from NIDDM and obese individuals. With the strong correlation between necrobiosis lipoidica and diabetes mellitus, we investigated the expression of Glut-1 in diabetic individuals with necrobiosis lipoidica (NL).

METHODS

A polyclonal anti-Glut-1 antibody was used with a standard immunoperoxidase technique to determine Glut-1 expression by fibroblasts in areas of sclerotic collagen from specimens taken from diabetic individuals with necrobiosis lipoidica,and non-diabetic individuals with scars and granuloma annulare (GA).

RESULTS

Our results showed Glut-1 expression in the areas of sclerotic collagen in patients with NL, possibly contributing to insulin resistance in these tissues.

CONCLUSIONS

Our findings raises the question as to whether abnormalities in glucose transport by fibroblasts in individuals with necrobiosis lipoidica contribute to the histopathologic changes.

Development and psychometric evaluation of the Caregiver Reciprocity Scale II

Caregiver reciprocity is the collective affective and behavioral expression of exchanges given and received between a caregiver and care receiver, and among family members. This psychometric investigation was designed to further examine the reliability and validity of the revised Caregiver Reciprocity Scale II (CRS II). Items were rewritten to reflect valued exchanges and balance among the entire family network, including spouses. An alpha of .83 for Warmth and Regard; .73 for Intrinsic Rewards of Giving; .83 for Love and Affection; and .75 for Balance Within Family Caregiving indicated acceptable internal consistency. The study, conducted with 176 spouse or adult children caregivers, provides additional support for the conceptual model of the four-factor solution. Construct validity was supported by the standardized factor loadings and goodness-of-fit indices obtained from confirmatory factor analysis. The results of the analysis of the measurement model, taken as a whole, demonstrate that the CRS II has adequate psychometric properties. Model parsimony was supported by an AGFI of .87, combined with an adjusted chi-square between 1.0 to 3.0. All but two item loadings were greater than .50. This, combined with the fact that all standardized loadings were twice the standardized errors and t-values were greater than 2.0, contributes to concluding that convergent validity was strong. Discriminant validity, evaluated by variance extracted estimates, and confidence interval (+/- two standard errors) around the correlation estimate between factors, was adequate. This study provided evidence to support the reliability and validity of the CRS II.

Cervical ectopy in adolescent girls with and without human immunodeficiency virus infection

The objective of this study was to examine factors, including human immunodeficiency virus (HIV) infection, associated with ectopy among adolescent girls aged 12-20 years who were participating in an ongoing study of HIV infection in adolescents. Samples for detection of bacterial vaginosis, Chlamydia trachomatis, and Neisseria gonorrhoeae and a high-resolution photograph of the cervix for ectopy measurement were collected. Ectopy data for 189 and 92 HIV-positive and -negative adolescents, respectively, were examined. Although univariate analysis found HIV infection and oral contraceptive use to be associated with the amount of ectopy, multivariate logistic regression analysis showed that only number of lifetime sex partners was a significant predictor, with more partners associated with less ectopy (odds ratio, 0.47; 95% confidence interval, 0.22-1.00; P=.05). In summary, adolescent girls with greater numbers of lifetime sex partners were more likely to have mature cervixes (less ectopy). HIV infection was not independently associated with ectopy.

Exposure risks and tetanus immunization in women of family owned farms. Implications for occupational and environmental health nursing

A sampling pool of 4,808 farms in 10 parishes across southeast Louisiana was used to examine the risk factors of farm women who engage in activities putting them at risk for tetanus and to examine the circumstances related to vaccination. Data were collected, via stratified random sampling, in summer 1998 resulting in 657 completed interviews. Only 53.6% of women were current with a tetanus booster, having received their immunization within the past 10 years. Just as many women received tetanus vaccination following an injury or accident as for prevention. As women aged, they were less likely to be compliant. In the South, a number of environmental factors contribute to the risk for tetanus exposure and infection. These risk factors were examined in light of compliance with tetanus booster compliance. Increasing awareness of risk is essential because although tetanus is uncommon, the death rate from tetanus is greater than 30%.