Protein based molecular markers provide reliable means to understand prokaryotic phylogeny and support Darwinian mode of evolution

The analyses of genome sequences have led to the proposal that lateral gene transfers (LGTs) among prokaryotes are so widespread that they disguise the interrelationships among these organisms. This has led to questioning of whether the Darwinian model of evolution is applicable to prokaryotic organisms. In this review, we discuss the usefulness of taxon-specific molecular markers such as conserved signature indels (CSIs) and conserved signature proteins (CSPs) for understanding the evolutionary relationships among prokaryotes and to assess the influence of LGTs on prokaryotic evolution. The analyses of genomic sequences have identified large numbers of CSIs and CSPs that are unique properties of different groups of prokaryotes ranging from phylum to genus levels. The species distribution patterns of these molecular signatures strongly support a tree-like vertical inheritance of the genes containing these molecular signatures that is consistent with phylogenetic trees. Recent detailed studies in this regard on the Thermotogae and Archaea, which are reviewed here, have identified large numbers of CSIs and CSPs that are specific for the species from these two taxa and a number of their major clades. The genetic changes responsible for these CSIs (and CSPs) initially likely occurred in the common ancestors of these taxa and then vertically transferred to various descendants. Although some CSIs and CSPs in unrelated groups of prokaryotes were identified, their small numbers and random occurrence has no apparent influence on the consistent tree-like branching pattern emerging from other markers. These results provide evidence that although LGT is an important evolutionary force, it does not mask the tree-like branching pattern of prokaryotes or understanding of their evolutionary relationships. The identified CSIs and CSPs also provide novel and highly specific means for identification of different groups of microbes and for taxonomical and biochemical studies

Prevalence and determinants of hypertension in elderly population of Raipur city, Chhattisgarh

Background: Demographic transition across globe leading towards greying of population. Worldwide, raised blood pressure is estimated to cause 12.8% of the total annual deaths. This account for 3.7% of total DALYs. Several community-based studies have served to emphasize that hypertension is rapidly emerging as a major public health problem. However, only a few of these studies included elderly people. The objectives of the present study were to evaluate the prevalence and factors influencing hypertension among elderly population of Raipur city.  Methods: This community based cross-sectional study was carried out in capital of Chhattisgarh, including urban and slum area from July 2013 to June 2014. Multistage simple random sampling methods were used. Study population comprises of all elderly 60 years and above residing in the study area for at least one year. A total of 640 subjects were included in study.Results: The overall prevalence of hypertension in present study was 50%, prevalent among females (55.49%),shows a significant positive association with body mass index, physical activity and age up to old age group (75-84)yrs. Surprisingly inverse association was observed with alcohol (P <0.001) and smoking (P <0.05) status.Conclusion: Our findings emphasize the public health importance of hypertension in the elderly in Raipur city, and need to strengthen the national programme for hypertension. From a public health perspective, there is definite need for screening of elderly.

An in vitro study of probiotic activity exhibited by Lactobacillus acidophilus and Lactobacillus rhamnosus on oral isolates of Streptococcus mutans and Candida albicans

Background: Oral infections caused by microorganisms have led to increased risk of oral health problems like dental caries (DC). Streptococcus mutans and Candida albicans are the organisms responsible for DC. The goal of the presented study was to investigate the potential of probiotics to prevent and treat DC. An in vitro assay was developed to investigate several probiotic strains for their ability to inhibit the aforementioned oral pathogens. Methods: 40 oral isolates of Streptococcus mutans and 51 oral isolates of Candida albicans were tested for probiotic activity against Lactobacillus acidophilus and Lactobacillus rhamnosus using agar overlay interference technique as prescribed by Fleming et al. Results: The zone of inhibition shown by L. acidophilus was higher than L. rhamnosus against Streptococcus mutans and Candida albicans. Conclusions: In conclusion the two probiotic strains L. acidophilus and L. rhamnosus exhibited inhibitory activity on S. mutans and C. albicans respectively in vitro

Magnetic Anisotropy of Co2MnSn1−xSbx Thin Films Grown on GaAs (001)

Heusler alloy Co2MnSn1−xSbx (x = 0.0, 0.5, and 1.0) thin films were grown on GaAs (001) substrates using pulsed laser deposition techniques. Growth parameters have been determined that result in highly magnetically anisotropic, crystalline, and oriented (001) films. The angular dependences, relative to the GaAs (001) crystallographic directions, of the coercive field Hc(θ) and the remanence Mr(θ) were determined from angle dependent magneto-optic Kerr effect (MOKE) measurements. It was found that Hc(θ) revealed higher order symmetry contributions to the magnetic anisotropy than did Mr(θ). The Fourier analysis of rotational MOKE data was used to determine the symmetry contributions to the total anisotropy

Induced Magnetic Anisotropy and Spin Polarization in Pulsed Laser-Deposited Co2MnSb Thin Films

Co2MnSb thin films were grown on glass and GaAs (001) substrates using pulsed laser deposition. The films were grown in magnetic fields (HG = 500 Oe and 0 Oe) that were applied in the plane of the substrate during the deposition process. Angle-dependent magneto-optic Kerr effect measurements for films grown on glass revealed a uniaxial magnetic anisotropy in the direction of the applied growth field. Films grown on GaAs (001) exhibited more complicated magnetic anisotropy behavior, due to additional contributions from the substrate. Point contact Andreév reflection spectroscopy measurements indicated that the spin polarizations of the films were about P~ 50%, with negligible difference between films grown in zero and non-zero applied fields

Magnetic and Transport Properties of Co2MnSnxSb1−x Heusler Alloys

We present the magnetic, structural, and transport properties of the quaternary Heusler alloys Co2MnSnxSb1−x (x = 0, 0.25, 0.50, 0.75, and 1.0), which have been theoretically predicted to be half-metallic. Magnetization measurements as a function of applied field show that the saturation moment for x = 1 (Co2MnSn) is near the Slater–Pauling value of 5μB; however, the moment for x = 0 (Co2MnSb) falls far short of its predicted value of 6μB. Resistivity as a function of temperature was measured from 5 to 400 K, and a phase transition from a half-metallic ferromagnetic phase to a normal ferromagnetic phase was observed between 50 and 80 K for all of the alloys. At low temperature (10 K\u3cT\u3c40 K), the resistivity ratio was found to vary as R(T)/R(T = 5 K) = A+BT2+CT9/2, where the T2 term results from electron-electron scattering, whereas the T9/2 term is a consequence of double magnon scattering