Kinetic theory of electromagnetic ion waves in relativistic plasmas

A kinetic theory for electromagnetic ion waves in a cold relativistic plasma is derived. The kinetic equation for the broadband electromagnetic ion waves is coupled to the slow density response via an acoustic equation driven by ponderomotive force like term linear in the electromagnetic field amplitude. The modulational instability growth rate is derived for an arbitrary spectrum of waves. The monochromatic and random phase cases are studied.Comment: 7 pages, 4 figures, to appear in Physics of Plasma

Nonlinear dynamics of large amplitude dust acoustic shocks and solitary pulses in dusty plasmas

We present a fully nonlinear theory for dust acoustic (DA) shocks and DA solitary pulses in a strongly coupled dusty plasma, which have been recently observed experimentally by Heinrich et al. [Phys. Rev. Lett. 103, 115002 (2009)], Teng et al. [Phys. Rev. Lett. 103, 245005 (2009)], and Bandyopadhyay et al. [Phys. Rev. Lett. 101, 065006 (2008)]. For this purpose, we use a generalized hydrodynamic model for the strongly coupled dust grains, accounting for arbitrary large amplitude dust number density compressions and potential distributions associated with fully nonlinear nonstationary DA waves. Time-dependent numerical solutions of our nonlinear model compare favorably well with the recent experimental works (mentioned above) that have reported the formation of large amplitude non-stationary DA shocks and DA solitary pulses in low-temperature dusty plasma discharges.Comment: 9 pages, 4 figures. To be published in Physical Review

Ion-acoustic solitary waves and shocks in a collisional dusty negative ion plasma

We study the effects of ion-dust collisions and ion kinematic viscosities on the linear ion-acoustic instability as well as the nonlinear propagation of small amplitude solitary waves and shocks (SWS) in a negative ion plasma with immobile charged dusts. {The existence of two linear ion modes, namely the `fast' and `slow' waves is shown, and their properties are analyzed in the collisional negative ion plasma.} {Using the standard reductive perturbation technique, we derive a modified Korteweg-de Vries-Burger (KdVB) equation which describes the evolution of small amplitude SWS.} {The profiles of the latter are numerically examined with parameters relevant for laboratory and space plasmas where charged dusts may be positively or negatively charged.} It is found that negative ion plasmas containing positively charged dusts support the propagation of SWS with negative potential. However, the perturbations with both positive and negative potentials may exist when dusts are negatively charged. The results may be useful for the excitation of SWS in laboratory negative ion plasmas as well as for observation in space plasmas where charged dusts may be positively or negatively charged.Comment: 13 pages, 9 figures; To appear in Physical Review

Correlation of DNA Ploidy with Progression of Cervical Cancer

The majority of squamous cell carcinomas of cervix are preceded by visible changes in the cervix, most often detected by cervical smear. As cervical cancer is preceded by long precancerous stages, identification of the high-risk population through detection of DNA ploidy may be of importance in effective management of this disease. Here we attempted to correlate aneuploid DNA patterns and their influence on biological behavior of flow-cytometry analysis of DNA ploidy which was carried out in cytologically diagnosed cases of mild (79), moderate (36), and severe (12) dysplasia, as well as “atypical squamous cells of unknown significance (ASCUS)” (57) along with controls (69), in order to understand its importance in malignant progression of disease. Cytologically diagnosed dysplasias, which were employed for DNA ploidy studies, 39 mild, 28 moderate, and 11 severe dysplasia cases were found to be aneuploid. Out of the 69 control subjects, 6 cases showed aneuploidy pattern and the rest 63 subjects were diploid. An aneuploidy pattern was observed in 8 out of 57 cases of cytologically evaluated ASCUS. The results of the followup studies showed that aberrant DNA content reliably predicts the occurrence of squamous cell carcinoma in cervical smear. Flow cytometric analysis of DNA ploidy may provide a strategic diagnostic tool for early detection of carcinoma cervix. Therefore, it is a concept of an HPV screening with reflex cytology in combination with DNA flow cytometry to detect progressive lesions with the greatest possible sensitivity and specificity

The Achievement of Glycaemic, Blood Pressure and LDL Cholesterol Targets in Patients with Type 2 Diabetes Attending a South African Tertiary Hospital Outpatient Clinic

Objectives: To determine differences in the control of multiple diabetes control parameters in a select group of subjects with type 2 diabetes (T2DM) after a four-year follow-up period.Design: Cross-sectional study.Setting and subjects: The initial 2009 study population consisted of 666 T2DM patients of whom only 261 (39.2%) were audited at the Charlotte Maxeke Johannesburg Academic Hospital. Outcome measures: Using a public sector database, retrospective data were obtained on the treatment of participants with T2DM attending a tertiary care setting and a descriptive analysis was done.Results: The mean age was 64 (SD 10.6) years, women represented 55% of the cohort and the mean duration of diabetes was 16 years (range 2–40 years) in 2013. Fewer patients achieved an HbA1c goal (of < 7%) in 2013 (15.5%) compared with 2009 (25.4%), whilst an additional 13.7% and 25.0% of the 261 patients reached blood pressure targets (< 140/80 mmHg) and LDL-C targets ( < 2.5 mmol/L), respectively.Conclusion: Overall, more patients in the study reached blood pressure and LDL-C targets but there were difficulties in achieving optimal glycaemic levels over the four-year period. This study highlights the complexities of managing risk factors in T2DM, especially glucose control.Keywords: Diabetes Mellitus, Management, Risk Factors, Target

Aryl esters and a coumarin from Aygyreia speciosa

192-19

Disubstituted tetrahydrofuran and an ester from Argyreia speciosa

299-30

A disubstituted pyrone from Centella asiatica

963-96

Implementing the Simple Biosphere Model (SiB) in a general circulation model: Methodologies and results

The Simple Biosphere MOdel (SiB) of Sellers et al., (1986) was designed to simulate the interactions between the Earth's land surface and the atmosphere by treating the vegetation explicitly and relistically, thereby incorporating biophysical controls on the exchanges of radiation, momentum, sensible and latent heat between the two systems. The steps taken to implement SiB in a modified version of the National Meteorological Center's spectral GCM are described. The coupled model (SiB-GCM) was used with a conventional hydrological model (Ctl-GCM) to produce summer and winter simulations. The same GCM was used with a conventional hydrological model (Ctl-GCM) to produce comparable 'control' summer and winter variations. It was found that SiB-GCM produced a more realistic partitioning of energy at the land surface than Ctl-GCM. Generally, SiB-GCM produced more sensible heat flux and less latent heat flux over vegetated land than did Ctl-GCM and this resulted in the development of a much deeper daytime planetary boundary and reduced precipitation rates over the continents in SiB-GCM. In the summer simulation, the 200 mb jet stream and the wind speed at 850 mb were slightly weakened in the SiB-GCM relative to the Ctl-GCM results and equivalent analyses from observations

Making light work of heavy metal contamination::The potential for coupling bioremediation with bioenergy production

Intense anthropogenic activity continues to expose the natural environment to heavy metal contamination. Whilst a number of physical and chemical solutions for remediation exist, the use of higher plants and algae for clean‐up of contaminated landscapes, termed “phytoremediation” and “phycoremediation”, respectively, offer an attractive and sustainable alternative. However, these remediation processes will always lead to a high‐moisture, heavy metal‐contaminated biomass, which must be further processed to partition, or render inert, the metal contaminants. Conversion of this metal‐rich biomass into second‐generation biofuels offers a useful route to subsidise the economics of remediation activities. Here we briefly review the various methods for bioremediation of heavy metals, and discuss the potential to produce bioenergy from these biomass sources. Ultimately, coupling the bioremediation activity to bioenergy production gives far‐reaching social and economic benefits; however, established processes such as direct combustion and anaerobic digestion risk releasing heavy metals back into the environment. Alternatively, thermochemical conversions such as pyrolysis or hydrothermal liquefaction (HTL) offer significant advantages in terms of the segregation of metals into a relatively inert and compact solid phase while producing a biocrude oil for bioenergy production. In addition, preliminary work suggests that the HTL process can also be used to partition essential macronutrients, such as N, P and K, into an aqueous medium, allowing additional nutrient recycling