Community structure and diversity of a tropical dry deciduous forest of Hastinapur region, India

The present study deals with quantitative analysis of vegetation of forest area in Hastinapur, India. A total 3 sites were selected for the study. The values of density and total basal area for different species ranged from 0.5 Ind100m-2 to 2.2 and 16.50 cm2tree-1 to 1055.0cm2tree-1. Most of the species on different sites were randomly and regularly distributed, none of the species were found with contagious distribution. The values of Cd and H’ were ranged from 0.003 to 0.035 and 0.000 to 0.014

A study on carbon sequestration in natural forests of India

Among the global common concerns, climate change has been identified as the most important environmental challenge faced by human beings. Emission of carbon dioxide, methane, nitrous oxide, chlorofluorocarbons and hydrocarbons are identified as green house gases causing warming of earth globally. Of these gases, CO2 alone accounts for 60 percent share. The most practical way of removing excess carbon from atmosphere and storing it in to a biological system is by absorption of atmospheric CO2 into the physiological system, plant biomass and finally into the soil . Carbon is thus sequestered into the plants and then the animals. Studies have established that Carbon sequestration by trees and forest could provide relatively low cost net emission reduction. Carbon management in forest is therefore one of the most important agenda in India in 21st century in context of green house gases effect and mitigation of global climate changes. Studies indicated that Indian forests share 1,083.81 MtC in the year 1994 to 3,907.67 MtC in the year 1993. Estimated rate of Carbon flux in selectedIndian planted forest reveals that planted forests of short rotation tree species with regular leaf shedding patterns have more capacity for carbon sequestering in litter which decomposes more rapidly than those with annual or bimodal leaf shedding patterns. Mixed planted forest of exotic and native species could be more efficient in sequestering Carbon than the monocultures. This contribution reviews Carbon sequestration in Indian forests at national level and site-specific situations;and elaborates some possible opportunities for sustainable Carbon forestry

Various aspects of soil and tree layer vegetation analysis in tropical dry deciduous forest of Hastinapur

Different parameters of Soil and vegetation analysis were carried out in Tropical dry deciduous forest of Hastinapur region of Uttar Pradesh. Vegetation of present study sites showed effects of various anthropogenic disturbances. The highly disturbed stand I showed low tree density while less disturbed stand III showed high tree density and good regeneration pattern. D-D curve were also drawn on the basis of the IVI of different species. Population structure of different tree species was drawn to understand the regeneration pattern. The most characteristic feature of the forest is dominance of xerophytic species and open forest canopy due to disturbances. Overgrazing and other biotic factors are making the area poor both in nutrient and top soil, which will eventually result in desertification of the Hastinapur in long run

Natural regneration of plant species as affected by biotic disturbances in Hastinapur forest of North West Uttar Pradesh, India

In the present study various phytosociological attributes like frequency, density and abundence of woody vegetation were analysed along the disturbance gradient in tropical dry deciduous forest of Hastinapur region of North west Uttar Pradesh, India. Three sites were analysed for floristic composition, distribution pattern, species diversity and dominance (i.e. Hillock,Block-1 and Block-2)Hillock was highly disturbed, while Block-1 and Block-2 were moderately and least disturbed sites respectively. Maximum number of tree, seedlings and saplings were recorded for Block-2 and minimum for Hillock. Number of shrub species was maximum on Hillockbecause of open forest canopy due to disturbances, which provide favourable conditions for growth of shrubs and other weeds. Most of species except shrubs were regular followed by random in distribution pattern. The value of CD and H’for trees 0.01 on Block-1 to 0.035 on Hillock and 0.00 on Block-2 to 0.014 on Hillock respectively. These low values clearly indicate aridity of the area and habitat destruction. Phytosociological study of this area indicates that there is an urgent requirement of conservation practice

Genetic diversity of Cryptosporidium isolates from patients in North India

SummaryBackgroundCryptosporidiosis is a significant cause of diarrheal illness in both immunocompetent and immunocompromised populations. Cryptosporidium species infect a wide range of hosts including humans. Different species are morphologically indistinguishable, and molecular techniques have become the key to detection and source tracking. The present study was designed to study the genetic diversity of human Cryptosporidium isolates in North India.MethodsCryptosporidium oocysts were detected in stool samples by special staining of fecal smears. DNA was extracted with a Qiagen kit and all samples were genotyped by small subunit ribosomal ribonucleic acid (SSU rRNA)-based nested PCR-restriction fragment length polymorphism (RFLP) tool using enzymes SspI and VspI. Cryptosporidium hominis and Cryptosporidium parvum isolates were subtyped by sequence analysis of the nested PCR amplified gp60 gene.ResultsFifty-three fecal samples were found to be positive for Cryptosporidium oocysts. RFLP analysis revealed 39 isolates as C. hominis and 13 isolates of C. parvum; one sample failed amplification. gp60-based sequencing of C. hominis and C. parvum divided them into eight subgenotype families and 17 subtypes. gp60-based sequencing identified seven cases of mixed infection with C. hominis and C. parvum/Cryptosporidium meleagridis and showed the presence of C. meleagridis in six HIV-positive patients that were indistinguishable in RFLP.ConclusionsCryptosporidium isolates obtained in the present study from patients in North India belonged to three species, eight subgenotype families, and 17 subtypes. The existence of many Cryptosporidium species, subgenotypes, and subtypes along with mixed infections reveals the complexity of Cryptosporidium transmission; this heterogeneity indicates stable cryptosporidiosis transmission in North India. The results may have further implications in understanding the epidemiology and control of this infection

Characterisation of the elastic properties of porous foams

International audienceAn experimental method for measuring the elastic constants of poroelastic foams as a function of frequency is presented. The method is based on the measurement of phase velocities of guided acoustic waves in a slab of the material. Standing waves are generated in the material and the phase velocities are evaluated using the spatial Fourier Transform of the displacement profile of the upper surface. The displacement is measured with the help of a Laser Doppler vibrometer along a line corresponding to the direction of propagation of plane surface waves. The spatial Fourier Transform provides the wave numbers and the phase velocities are obtained from the relationship between wave number and frequency. The phase velocity of several guided modes could be measured in highly porous foams saturated by air. The modes were also studied theoretically and from the theoretical and experimental results, it was possible to determine the frequency behavior of the real part of the shear modulus and in a frequency range higher than the traditional methods. Experimental results concerning guided waves in isotropic porous materials tend to suggest that information about the anisotropy of the elastic matrix can also be obtained

Guided elastic waves in porous materials saturated by air under Lamb conditions

International audienceThe propagation of guided elastic waves in porous materials saturated by air under Lamb conditions is studied theoretically and experimentally. The modes are derived from expressing the boundary conditions on the normal and tangential stresses and the displacements at the interfaces between the porous layer and the surrounding fluid. The stresses and the fluid pressure inside the porous medium are obtained from Biot's equations of poroelasticity. Symmetrical and antisymmetrical modes are found when the porous layer is loaded by the same fluid on both sides. Damping mechanisms include viscous and thermal exchanges between the solid and the fluid, in addition to the classical structural damping. Using an experimental setup based on the generation of standing waves in the layer and taking the spatial Fourier transform of the displacement profile, the phase velocities of three modes were measured for two porous materials in a frequency range between 80 Hz and 4 kHz. The measurements confirm the theoretical predictions and provide information on the shear modulus of a sound-absorbing material in a wide frequency range

Anti-bacterial activity of inorganic nanomaterials and their antimicrobial peptide conjugates against resistant and non-resistant pathogens

This review details the antimicrobial applications of inorganic nanomaterials of mostly metallic form, and the augmentation of activity by surface conjugation of peptide ligands. The review is subdivided into three main sections, of which the first describes the antimicrobial activity of inorganic nanomaterials against gram-positive, gram-negative and multidrug-resistant bacterial strains. The second section highlights the range of antimicrobial peptides and the drug resistance strategies employed by bacterial species to counter lethality. The final part discusses the role of antimicrobial peptide-decorated inorganic nanomaterials in the fight against bacterial strains that show resistance. General strategies for the preparation of antimicrobial peptides and their conjugation to nanomaterials are discussed, emphasizing the use of elemental and metallic oxide nanomaterials. Importantly, the permeation of antimicrobial peptides through the bacterial membrane is shown to aid the delivery of nanomaterials into bacterial cells. By judicious use of targeting ligands, the nanomaterial becomes able to differentiate between bacterial and mammalian cells and, thus, reduce side effects. Moreover, peptide conjugation to the surface of a nanomaterial will alter surface chemistry in ways that lead to reduction in toxicity and improvements in biocompatibility

Efficacy of Accent Modification Training for International Medical Professionals

International medical graduates (IMGs) comprise 26% of the U.S. physician work force. While IMGs bring all their knowledge and expertise, their pronunciation and intonation patterns often become a barrier in their ability to be understood. This breakdown in communication can affect physician-patient or physician-staff understanding and hence patient care. This study assessed the efficacy of an accent reduction program provided to IMGs and international medical researchers (IMRs) to address these communications problems. A pre and post course self-evaluation by the 82 participants, a pre and post audio-tape assessment by the course instructor, and a pre and post videotape assessment by two independent observers all pointed to significant improvement in their abilities to pronounce words distinctly, stress words or syllables more accurately and use body language/facial expressions appropriately. The results suggest that appropriate and focused training directed at improving the communication skills of non-native English speakers is highly effective