Liming of alfalfa in a greenhouse study

The use of agricultural lime has been recognized down through the ages as a practice that is basic to good soil management in humid regions. The effects of liming are a complex of many contributing physical, chemical. microbiological and physiological factors. Its direct function is to correct soil acidity, improve soil structure and create an environment suitable to the growth and development of plants. Liming enhances the availability and plant uptake of elements such as nitrogen, phosphorus, molybdenum, calcium, and magnesium. At the same time it drastically reduces the concentration of iron, aluminum and manganese, which under very acid conditions are apt to be present in toxic quantities. In at least some soils, it enhances the availability of potassium. Lime stimulates the general-purpose. heterotrophic soil organisms, thereby increasing their activity on organic matter and the releasing of nitrogen. This favors the formation of humus and also encourages the elimination of certain intermediate products that might be toxic to higher plants. Within the plant, too, lime performs many functions. Calcium is essential for the growth of the meristems. the development and functioning of root tips, and for certain enzymatic reactions involved in respiration. The uptake of nutrients by roots of plants from the soil medium is a complex physiological process, the rate of which is greatly influenced by environmental factors. Greenhouse experiments have several advantages in this regard, most important of which is the control of numerous environmental factors. It is also possible under greenhouse conditions to design experiments to include a large number of treatments and a variety of soils; they can be carried out at any time of the year Irrespective of the season. Furthermore, Investigations of a fundamental nature such as soil-plant relationships, can be made in a greenhouse without the involvement of elaborate field studies, high cost and undue labor. At the same time, they can serve as pilot projects for appropriate field studies in the future. The influence of lime on acid soils in promoting the growth, yield and uptake of nutrients is one of fundamental importance and immediate concern to the agronomist. Lime-fertilizer experiments in the greenhouse involving the use of calcium, phosphorus and potassium on acid infertile soils are therefore very important in giving some indication as to the wise use of these nutrients. Since root development of crops in acid soils is very much dependent on the soil condition, its lime content and the nature of its zone of penetration, the placement of lime as an additional factor in the balance of fertilization assumes relatively great importance. This work was undertaken with the following objectives in view: 1. To study the influence of liming and fertilization of an acid soil on growth, yield, root development and uptake of various cations by plants. 2. To study the influence of placement of lime in different layers of the soil on the above factors. Hartsells loam was the soil used for the study. It was low in all nutrients. Alfalfa was used as the indicator plant because it is known to be sensitive to soil acidity

EVALUATION OF ANTIMICROBIAL POTENTIALS OF Cardiospermum halicacabum Linn.

Antimicrobial activity of Cardiospermum halicacabum shoot extracts were studied on gram-positive bacteria such as Staphylococcus aureus, Bacillus substilis, and gram-negative bacteria such as E.coli, Proteus vulgaris, and fungus Candida albicans. Disc diffusion method was used to study the antimicrobial activity of aqueous, ethanol, chloroform and ether extracts of C. halicacabum. Ampicillin was used as reference standard at 10 mg/disc concentration. Extracts of C. halicacabum exhibited a significant antibacterial activity except the aqueous extract. Ethanolic extract was found to be very effective with maximum activity index (0.84). The ethanolic extract exhibited minimum inhibitory concentration (MIC of 0.25 mg/mL against Staphylococcus aureus, Bacillus substilis, E. coli and Proteus vulgaris and 0.125 mg/mL against Candida albicans. The MIC of chloroform and ether extracts ranged between 0.25 and 1.0 mg/ml against the test organisms. All the extracts showed antifungal activity against Candida albicans. Key words: antimicrobial activity, Cardiospermum halicacabum shoot system, solvent extraction,

Epidemiological and Clinical Profile of Human Leptospirosis in North Chennai: A Study of 90 cases

INTRODUCTION: Infectious disease is an important cause of morbidity and mortality in our country. Leptospirosis is one of the most widespread zoonotic infection in world today and it has long been considered a rare zoonotic disease in India with only sporadic cases being reported. The disease has been reported from various States during the monsoon months in mini epidemic proportions. Cases have been reported from Kerala, Tamil Nadu, Gujarat, Andamans & Nicobar islands, Karnataka, Maharashtra, Orissa, Puducherry and in other states like Uttar Pradesh and Andhra Pradesh. Leptospirosis has been under reported and under diagnosed from India due to a lack of awareness of the disease and lack of appropriate laboratory diagnostic facilities in most parts of the country. Combining clinical expertise and awareness with rapid tests for diagnosis will increase the recognition of patients with leptospirosis. Leptospirosis can be diagnosed only by laboratory tests, as the clinical features are non-specific. Recently, the diagnosis of leptospirosis has been simplified by utilizing the Modified Faine’s Criteria. This study has been undertaken to study the epidemiological profile and clinical profile of leptospirosis in our hospital, which caters to the population in North Chennai. AIM OF THE STUDY: 1. To evaluate the epidemiological risk factors for leptospirosis. 2. To study the clinical profile leptospirosis utilizing Modified Faine’s Criteria in North Chennai. PATIENTS AND METHODS: Patients admitted to the medical wards of Government Stanley Medical College Hospital with fever due to infectious disease of duration of more than 5 days who were tested positive for leptospirosis utilizing MSAT test (Macroscopic Slide Agglutination Test) (titers > 2+) were taken up for the study. We have utilized a simple and sensitive MSAT for early detection of leptospirosis and utilized Modified Faine’s score of > 25 (Clinical (A) + Environmental (B) + Laboratory (C)) for the diagnosis of leptospirosis. All patients tested positive by MSAT were further confirmed by MAT (Microscopic Agglutination Test) with titers of > 1:80. These patients were evaluated for relevant epidemiological, clinical and lab profiles. Patients aged >12 years were taken up for the study. The period of study was from February 2006 to May 2007. Diagnostic Criteria: Leptospirosis was diagnosed utilizing Modified Faine’s Criteria5 – Clinical (A), Epidemiological (B), Laboratory data (C) (Score > 25). Exclusion Criteria: Malaria, Urinary tract infection, Tuberculosis, Enteric fever, viral hepatitis and paediatric cases were excluded from the study. The following data were noted: 1. Age, Sex, Occupation and address were noted. 2. Epidemiological profile – H/o rainfall, H/o contact with contaminated environment (Poor sanitation, poor drainage facilities, walking barefoot, recreational activities involving the contact with contaminated water and bathing in ponds), H/o animal contact (with rodents, contact with domestic animals) were noted. RESULTS: A total of 90 patients diagnosed to have leptospirosis were analyzed. There were 56 males and 34 females with mean age of 37.45 years (Table 19) In the age/sex group distribution data shows that maximum number of cases were seen in age group between 31 to 40 years (Table 20). Among the leptospirosis cases, lowest age was 13 and highest age was 74 years. As age advances, the leptospirosis incidence decreased in our study group. CONCLUSION: 1. This study has revealed the role of contaminated environment in the transmission of leptospirosis. Among the contact with contaminated environment, poor sanitation (inefficient garbage disposal) and walking barefoot are the most important epidemiological risk factors. Recreational activities and bathing in the contaminated water, rainfall and animal contact are the other epidemiological risk factors. Leptospirosis can also occur in non-monsoon months due to the persistence of the contaminated environment. Out door manual workers are at risk of acquiring leptospirosis. 2. Anicteric Leptospirosis (76.6%) is the commonest clinical presentation. Lower incidence of jaundice and renal failure are noted. 3. Hypokalemia and ECG changes in leptospirosis are also the important markers of severe illness as like renal and hepatic dysfunctions. 4. There were no mortality. 5. Modified Faine’s Criteria with simple diagnostic test such as MSAT makes the diagnosis easy, simple and early and decreases the mortality due to leptospirosis. It is recommended that all fever patients should be evaluated for leptospirosis especially in endemic areas

Effectiveness of structured teaching programme on knowledge regarding risk factors and prevention of suicidal behaviour among adolescents in a selected college, Salem

This study was carried out to assess the Effectiveness of Structured Teaching Programme on Knowledge regarding Risk factors and Prevention of Suicidal Behaviour among Adolescents in a selected College, Salem. A quantitative evaluative approach with a pre-experimental (one group pre test-post test) design was adopted, the setting of the study was Sri Vidya Mandir College, Salem. The sample size was 60, who were selected by systematic random sampling technique. A Structured Selfadministered questionnaire was used to assess the knowledge of the adolescents. The investigator involved the adolescents on Structured Teaching Programme regarding Risk factors and prevention of Suicidal Behaviour by using a Power-point slide presentation followed with pre-test. On 7th day, the post test was conducted. The collected data were analyzed by using both descriptive and inferential statistical methods, and interpretations were made based on the objectives of the study. The study findings revealed that during Pre-test, the knowledge regarding risk factors and prevention of suicidal behaviour among adolescents 45 (75%) had inadequate knowledge, 15 (25%) had moderately adequate knowledge and none of them had adequate knowledge. During post test, 23 adolescents (38.33%) had adequate knowledge, 37 (61.67%) had moderately adequate knowledge and none of them had inadequate knowledge. The mean score during pre-test was 9.9±3.88 and the mean score during post test was 17.03±4.12. The paired ‘t’ value was 16.84 which was significant at p≤0.05 level. Thus it shows that the structured teaching programme was effective in improving knowledge regarding risk factors and prevention of suicidal behaviour among adolescents. Therefore the hypothesis H1 was retained. There was no significant association found between the pre-test scores on knowledge regarding risk factors and prevention of suicidal behaviour and the selected demographic variables at p≤0.05 level. Hence the stated hypothesis H2 was rejected. The study concluded that the structured teaching programme was effective among adolescents to improve the knowledge regarding risk factors and prevention of suicidal behaviour

Tuning the Hydrophobicity of Layer-Structure Silicates To Promote Adsorption of Nonaqueous Fluids: Effects of F– for OH– Substitution on CO2 Partitioning into Smectite Interlayers

The intercalation of non-aqueous fluids in the nanopores of organic and inorganic materials is of significant interest, particularly in the energy science community. Recently, XRD and computational modeling results have shown that structural F- for OH- substitution in layered silicates makes them more hydrophobic. Here, we use Grand Canonical Molecular Dynamics (GCMD) calculations to investigate how increasing the F-/(F-+OH-) ratio of a prototypical layered silicate (the smectite Na-hectorite) impacts the intercalation behavior of CO2 and H2O at elevated temperature and pressure. At the conditions of this study (T = 323 K, P = 90 bar, water-saturated CO2), increasing F- for OH- substitution causes decreasing total CO2+H2O intercalation, increasing CO2/(CO2+H2O) ratios in the interlayer galleries, and an increasing energy barrier to CO2 and H2O intercalation. CO2 intercalation is greatest at monolayer basal spacings, and the results support the idea that with Na+ as the exchangeable cation the interlayers must be propped open by some H2O molecules to allow CO2 to enter the interlayer galleries. The computed immersion energies suggest that the bilayer or a more expanded structure is the stable state under these conditions, in agreement with experimental results, and that the basal spacings of the minimum energy 2L structures increase with increasing F- for OH- substitution. These results are consistent with a wide range of experimental data for smectites at ambient conditions and elevated pressures and temperatures and suggest that F- for OH- substitution in conjunction with reduced structural charge and exchange with large, low charge cations may increase the ability of smectite minerals to incorporate hydrophobic species such as CH4, CO2, H2, and other organic compounds

Inquiry of inclined magnetic field effects on Walter –B nanofluid flow with heat generation / absorption

The article deals with Walter-B nanoliquid flow towards a extending surface with inclined magnetic field effects. Thermal relaxation analysis is made by non fourier heat flux model. Radiation, heat generation / absorption impacts are included. The non linear Partial governing systems are rebuild into nonlinear ordinary systems with the assist of proper similarity transformations. The graphical results are portrayed for velocity, concentration and temperature profile. The physical entitles of heat and mass transfer rates are graphically reported. The comparission with previous results notified the excellent agreement

Cation and Water Structure, Dynamics, and Energetics in Smectite Clays: A Molecular Dynamics Study of Ca-Hectorite

The incorporation of Ca2+ into smectite minerals is well-known to have a significant effect on the swelling behavior and mechanical properties of this environmentally and technologically important group of materials. Relative to common alkali cations such as Na+, K+, and Cs+, Ca2+ has a larger charge/ionic radius ratio and thus interacts very differently with interlayer water molecules and the oxygens of the clay basal surface. Recent 2H and 43Ca NMR studies of the smectite mineral, hectorite, show that the molecular scale interlayer dynamics is quite different with Ca2+ than with alkali cations. Classical molecular dynamics (MD) simulations presented here use a newly developed hectorite model with a disordered distribution of Li+/Mg2+ substitutions in the octahedral sheet and provide new insight into the origin of the effects of Ca2+ on the structure, dynamics, and energetics of smectite interlayers. The computed basal spacings and thermodynamic properties suggest the potential for formation of stable monolayer hydrates that have partial and complete water contents, a bilayer hydrate, and possible expansion to higher hydration states. The system hydration energies are comparable to those previously calculated for Ca–montmorillonite and are more negative than for Cs– and Na–hectorite due to the higher hydration energy of Ca2+. The coordination environments of Ca2+ change significantly with increasing interlayer hydration, with the extent of coordination to basal oxygens decreasing as the number of interlayer molecules increases. On external (001) surfaces, the H2O molecules closest to the surface are adsorbed at the centers of ditrigonal cavities and bridge Ca2+ to the surface. The Ca2+ ions on the external surface are all in outer-sphere coordination with the basal oxygens of the surface, and the proximity-restricted region with a significant number of Ca2+ is approximately 6 Å thick. Quantification of these interactions provides a basis for understanding intercalation of Ca2+ by organic species and smectite minerals

Structure, Energetics, and Dynamics of Cs+ and H2O in Hectorite: Molecular Dynamics Simulations with an Unconstrained Substrate Surface

Classical molecular dynamics simulations were performed for the smectite clay hectorite with charge-balancing Cs+ cations using a newly developed structural model with a disordered distribution of Li/Mg substitutions in the octahedral sheet and the fully flexible CLAYFF force field. Calculations for systems with interlayer galleries containing 0–19 H2O/Cs+ suggest that the monolayer hydrate is the only stable state at all relative humidities at ambient pressure and temperature, in agreement with experimental results and previous molecular calculations. The basal spacing of this structure is also in good agreement with experimental values. In contrast to previous molecular modeling results, however, the new simulations show that interlayer Cs+ occurs on 2 different inner sphere adsorption sites: above the center of ditrigonal cavities and above Si tetrahedra. Unlike previous simulations, which employed a rigid clay model and fixed orientations of the structural −OH groups, the present results are obtained for an unconstrained clay substrate structure, where the structural −OH groups are able to assume various orientations, including being nearly parallel to the clay layers. This flexibility allows the Cs+ ions to approach the surface more closely above the centers of the hexagonal rings. In this structural arrangement, Cs+ ions are not hydrated by the H2O molecules which share the same interlayer plane, but rather by the H2O molecules coordinated to the opposite surface. In contrast, on the external basal surface, a significant fraction of H2O molecules are adsorbed above the centers of ditrigonal cavities adjacent to adsorbed Cs+ ions. For these H2O molecules, both HH2O atoms coordinate and H-bond to Ob surface oxygen atoms. The mean residence times for the Cs+–H2O, Cs+–Ob, and H2O–Ob coordination pairs show that Cs+ ions are more strongly coordinated with Ob atoms than H2O molecules. This result is the opposite of the behavior in Ca-hectorite, due to the much smaller hydration energy of Cs+ compared to that of Ca2+

Diffusion Behavior of Methane in 3D Kerogen Models

As global energy demand increases, natural gas recovery from source rocks is attracting considerable attention since recent development in shale extraction techniques has made the recovery process economically viable. Kerogens are thought to play an important role in gas recovery; however, the interactions between trapped shale gas and kerogens remain poorly understood due to the complex, heterogeneous microporous structure of kerogens. This study examines the diffusive behavior of methane molecules in kerogen matrices of different types (Type I, II, and II) and maturity levels (A to D for Type II kerogens) on a molecular scale. Models of each kerogen type were developed using simulated annealing. We employed grand canonical Monte Carlo simulations to predict the methane loadings of the kerogen models and then used equilibrium molecular dynamics simulations to compute the mean square displacement of methane molecules within the kerogen matrices under reservoir-relevant conditions, that is, 365 K and 275 bar. Our results show that methane self-diffusivity exhibits some degree of anisotropy in all kerogen types examined here except for Type I-A kerogens, where diffusion is the fastest and isotropic diffusion is observed. Self-diffusivity appears to correlate positively with pore volume for Type II kerogens, where an increase in diffusivity is observed with increasing maturity. Swelling of the kerogen matrix up to a 3% volume change is also observed upon methane adsorption. The findings contribute to a better understanding of hydrocarbon transport mechanisms in shale and may lead to further development of extraction techniques, fracturing fluids, and recovery predictions