Calcium carbonate precipitation by different bacterial strains

Bacteria are capable of performing metabolic activities which thereby promote precipitation of calcium carbonate in the form of calcite. In this study, it is shown that microbial mineral precipitation was a result of metabolic activities of some specific microorganisms. Concrete microorganisms were used to improve the overall behavior of concrete. It was predicted that bacterial calcium carbonate (CaCO3) precipitation occurs as a byproduct of common metabolic processes such as urea hydrolysis. In this study, ureolytic bacteria that were capable of precipitating calcium carbonate were isolated and further their urease activity was tested based on the production of urease. Scanning electron microscopy (SED) analysis revealed the direct involvement of these isolates in calcium carbonate precipitation. The production of calcite was further confirmed by x-ray diffraction (XRD) and energy-dispersive x-ray (EDX) analysis.Key words: Bacteria, urease activity, microbial mineral precipitation, scanning electron microscope-energydispersive x-ray, x-ray diffraction

Ministers and Civil Servants Relations in India: an Evaluation

In a parliamentary form of government, like in India, there exist two types of executives i.e. political or elected and permanent executive. Political executive derives its power from people and enjoys the power by virtue of constitutional position, while permanent executive or civil servant is selected on merit basis and accumulate its power due to an administrative position and technical expertise. The system of a democratic government is based on the principle of popular sovereignty wherein the supreme rests in people or their elected representative. Political executive or Minister is assisted by a civil servant. A balanced relationship between them is essential for smooth and efficient functioning of government. Minister and civil servant act as two pillars of the parliamentary form of government and weakness of any one of them will adversely affect the performance of government. Theoretically political and permanent executives perform a different role in government but in practice, their work is often overlapping and difficult to differentiate it

Students’ Perceptions of Justice: Application of Sanctions, Guilt, and Responsibility in Campus Sexual Assault Cases

Despite growing attention to adjudication of campus sexual assault cases, little is known how students perceive “justice” for such cases. The present study examined whether victim, perpetrator, and assault characteristics influenced students’ perceptions of: whether a sanctionable violation occurred; the type of sanction to be applied; perceived severity of the sanction; proportion of guilt attributable to the victim and perpetrator; and level of responsibility of the victim and perpetrator. Fourteen factors pertaining to potential negative evaluation of rape victims were derived; thus, a non-factorial vignette survey design focusing only on each main effect was employed. 846 college students responded to one of four versions of a randomly distributed survey each containing eight vignettes that varied to represent all levels of the 14 factors. Students were not consistent in their application of sanctions or assignment of guilt or responsibility for the sexual assault vignettes, but rather were influenced in their ratings for 10 of the 14 factors. Students responded differentially to levels of the following factors: psychological impact on the victim, victim’s medical consequences, reason for the victim’s incapacitation leading to assault, consistency of victim’s and perpetrator’s accounts of the assault, sexual orientation of the victim, type of forced sex, number of perpetrators involved, fraternity membership of the perpetrator, gender of the perpetrator, and victim’s initial display of sexual interest in the perpetrator. Cases consistent with rape myths appear to influence students’ perceptions of justice. Findings are discussed in terms of implications for research and prevention programming

The Methods to Improve Quality of Service by Accounting Secure Parameters

A solution to the problem of ensuring quality of service, providing a greater number of services with higher efficiency taking into account network security is proposed. In this paper, experiments were conducted to analyze the effect of self-similarity and attacks on the quality of service parameters. Method of buffering and control of channel capacity and calculating of routing cost method in the network, which take into account the parameters of traffic multifractality and the probability of detecting attacks in telecommunications networks were proposed. The both proposed methods accounting the given restrictions on the delay time and the number of lost packets for every type quality of service traffic. During simulation the parameters of transmitted traffic (self-similarity, intensity) and the parameters of network (current channel load, node buffer size) were changed and the maximum allowable load of network was determined. The results of analysis show that occurrence of overload when transmitting traffic over a switched channel associated with multifractal traffic characteristics and presence of attack. It was shown that proposed methods can reduce the lost data and improve the efficiency of network resources.Comment: 10 pages, 1 figure, 1 equation, 1 table. arXiv admin note: text overlap with arXiv:1904.0520

Chemical Short-Range Order in Selenide and Telluride Glasses

International audienc

Antimicrobial activity of Ocimum sanctum leaves extracts and oil

The aim of this study was to evaluate the antimicrobial effects of ethanol, Hexane and Chloroform leaf extracts of O. sanctum against pathogenic bacteria to determine their potentials as antibacterial agent. Ocimum sanctum Linn known as Holy Basil is an aromatic plant native to the tropics of Asia and Africa being medicinally important plant in the family Lamiaceae. The family Lamiaceae is one of the most exploited medicinal plant family worldwide not only as a source of medicinal plants but also with its valuable essential oils being used as spices and flavours for various food products. Leaves have petioles, and are ovate, up to 5 cm long, usually slightly toothed. Leaves were separated from the stem, washed in clear water and dried until they were adequately dry to be ground (dried for 7 days). Dried leaves were powdered separately in an electric grinder until a homogenous powder was obtained. Ethanolic, Hexane, Chloroform extract was prepared from the powder obtained using “cold extraction method. The activity of Tulsi extract against K. pneumonia & Staphylococcus aureus was found to be higher at a concentration of 100% followed by 75% & 50% respectively. The maximum zone of inhibition was found to be 21&11mm against Kleibsiella pneumonia and 18&15mm against Staphylococcus aureus. The antimicrobial efficacy of Ocimum sanctum leaves indicates that the plant possesses potent antimicrobial properties as well as Ocimum is widespread in India, it can be recommended as an easily available and renewal source of antimicrobial agent instead of synthetic chemicals. Keywords:  Ocimum santum, Staphylococcus aureus, Klebsialla pneumonia, Disc Diffusio

Screening of antioxidant property of Eclipta alba

The aim of the study was to examine the possible antioxidant activities of the methanolic extracts of medicinal plants, Eclipta alba. We examined for such properties such as nitric oxide radical scavenging assay, DPPH radical scavenging activity. Free radicals are atoms or molecules that have one or more unpaired electrons on its outer orbital, highly reactive, and could damage cell inside human body. Human body produce antioxidant to neutralize free radicals, but human ageing and stress oxidative conditions would increase the formation of free radicals, therefore an exogenous antioxidant are needed. Asteraceae is the largest family among the plant kingdom, therefore it has a great potential as source of exogenous antioxidant. The flavonoid content of the plant extract was estimated by the method of (Lamaison and Carnat, 1990). Briefly 1.0 ml of plant extract was mixed with 1.0 ml of aluminium chloride reagent and resultant colour was read at 430 nm. The flavonoid content of the extract was expressed as mg quercetin equivalent/gm dry wt. of extract. The coarsely powdered plant materials of Eclipta alba (2000 g) were extracted separately to exhaustion in Soxhlet apparatus for 72 hours by using methanol solvent The crude extract was filtered using 125 mm Whatman® qualitative filter paper under sterile condition. A methanol solution of the sample at various concentrations was added to 0.5 ml of 0.1 mM methanolic solution of DPPH and allowed to stand for 30 min at 25°C in darkness. The absorbance of the sample was measured at 517 nm. A 0.1 mM solution of DPPH in methanol was used as control, whereas ascorbic acid was used as reference standard.  The absorbance of the pink chromophore formed during the diazotization of the nitrite with sulphanilamide and the subsequent coupling with naphthyl ethylenediamine dihydrochloride was measured at 546 nm.  The percentage of inhibition of the extract shown 39% in 25µg and in 100µg it was 73 percent

Short range order in Ge-Ga-Se glasses

International audienc