1,016 research outputs found
Grass and herb photosynthesis and productivity in a resource-limited Eucalyptus woodland under elevated atmospheric CO2
It has been suggested that plant species from the warmer ecosystems will show different and potentially larger photosynthesis and productivity responses to elevated CO2 (eCO2, ambient + 150 ppm) compared to those from the cold temperate ecosystems, on the basis of higher average annual temperature and greater water deficits in the former ecosystems. Based on these expectations, it has further been predicted that the warm water-limited ecosystems may have a greater potential to sequester the extra C that has been assimilated under eCO2. However, empirical evidences testing these expectations are scarce. The overall aim of this thesis was to investigate the effects of eCO2 on photosynthesis and productivity responses of the evergreen C3 herbaceous species from the understory of a periodically water-limited warm-temperate Eucalyptus woodland. In a three-year field study conducted at the Eucalyptus free-air CO2 enrichment experiment (EucFACE), I investigated how eCO2-induced enhancement of photosynthetic rates (Anet) in herbaceous species varied with seasonal water availability. During the second and third year of CO2 fertilisation at EucFACE, I measured the seasonal photosynthetic acclimation responses to eCO2 in two dominant species- a C3 forb and a C3 grass, and measured responses of peak above-ground biomass to eCO2 for total forbs and grasses. In a glasshouse experiment, I tested whether the species or functional groups growing under similar water inputs and nutrient availability differed in their photosynthetic or biomass allocation and growth responses to eCO2 for two C3 forbs and two C3 grasses. also evidence of photosynthetic acclimation under eCO2 in the dominant C3 herbaceous species, especially during the peak growing season of spring. Also, there was no proportional stimulation of peak above-ground biomass in the understory grasses and forbs, which may have been a result of lack of a âwater-savings effectâ of eCO2 and/or higher soil nutrient limitation. C3 grasses and C3 forbs differed in their photosynthetic and biomass allocation responses to eCO2. Differences in leaf N content, N allocation and changes in above-ground biomass allocation likely affected the CO2 responsiveness in these functional groups. In particular, there was an ability to maintain greater leaf area index, N allocation to photosynthesis and avoid down-regulation under eCO2 by the grasses but not by the forbs. Findings from the current study suggest that interactions between seasonal water-availability eCO2 will be critical in determining relative Anet enhancement response in herbaceous species from a water-limited ecosystem. However, the enhancement response may not be mediated via a âwater-savings effectâ of eCO2, which contrasts with the earlier findings from cold temperate ecosystems. Furthermore, evidence of photosynthetic capacity down-regulation in the dominant species and lack of relative increase in biomass under eCO2, suggest a limited capacity of the understory herbaceous species from a grassy woodland to respond to eCO2 and ultimately act as an aboveground C sink in future
Hysteresis in a magnetic bead and its applications
We study hysteresis in a micron-sized bead: a non-magnetic matrix embedded
with super- paramagnetic nanoparticles. These hold tremendous promise in
therapeutic applications as heat generating machines. The theoretical
formulation uses a mean-field theory to account for dipolar interactions
between the supermoments. The study enables manipulation of heat dissipation by
a compatible selection of commercially available beads and the frequency f and
amplitude ho of the applied oscillating field in the labortory. We also
introduce the possibility of utilizing return point memory for gradual heating
of a local region.Comment: 8 pages, 4 figure
Radio and infrared study of the star forming region IRAS 20286+4105
A multi-wavelength investigation of the star forming complex IRAS 20286+4105,
located in the Cygnus-X region, is presented here. Near-infrared K-band data is
used to revisit the cluster / stellar group identified in previous studies. The
radio continuum observations, at 610 and 1280 MHz show the presence of a HII
region possibly powered by a star of spectral type B0 - B0.5. The cometary
morphology of the ionized region is explained by invoking the bow-shock model
where the likely association with a nearby supernova remnant is also explored.
A compact radio knot with non-thermal spectral index is detected towards the
centre of the cloud. Mid-infrared data from the Spitzer Legacy Survey of the
Cygnus-X region show the presence of six Class I YSOs inside the cloud. Thermal
dust emission in this complex is modelled using Herschel far-infrared data to
generate dust temperature and column density maps. Herschel images also show
the presence of two clumps in this region, the masses of which are estimated to
be {\sim} 175 M{\sun} and 30 M{\sun}. The mass-radius relation and the surface
density of the clumps do not qualify them as massive star forming sites. An
overall picture of a runaway star ionizing the cloud and a triggered population
of intermediate-mass, Class I sources located toward the cloud centre emerges
from this multiwavelength study. Variation in the dust emissivity spectral
index is shown to exist in this region and is seen to have an inverse relation
with the dust temperature.Comment: 20 pages, 16 figures, accepted for publication in MNRA
SYSTEMIC PHAEOHYPHOMYCOSIS DUE BY ALTERNARIA ALTERNATA: CASE REPORTS, IN-VITRO SENSITIVITY AND EXOANTIGEN STUDIES.
Alternaria alternata is the most frequently encountered species of Alternaria causing opportunistic mycoses. We report two cases of phaeohyphomycosis in which Alternaria alternata was isolated from peripheral blood samples of 35 year and 21 year old male TB and post operative patients respectively. The direct microscopic examination of the blood samples revealed dark dematiaceous, septate mycelium. A. alternata was repeatedly isolated from the clinical samples of both the patients. Ketoconazole with the MIC of 10 mgml-1 was found to be the best effective drug against both the Alternaria alternata strains tested in vitro. In the present study we tried to evaluate the role of exoantigens in the serological diagnosis of such infections. The exoantigen of A. alternate on SDS-PAGE analysis exhibited two bands of 15Kda and 67Kda. The antisera raised in rabbit against. A alternata exoantigen showed humoral response after one week of immunization of ODD method. No cross reactivity was seen with antisera raised in rabbit against Curvularia verreculosa and Cladosporum cladosporiodides. Formation of specific precipitin bands and no cross reactivity suggests the usefulness of Alternaria alternata exoantigen as diagnostic tool. The antisera analysis by SDS-PAGE revealed several additional bands particularly higher than 67 Kda molecular weight as compared to the normal (unchallenged) sera from the same rabbit. Whether any of these bands could be treated as specific marker for diagnosis needs further investigations. Keywords- opportunistic, phaeohypomycosis, Alternaria alternata, minimal inhibitory concentration (MIC
BLIND DIGITAL WATERMARKING SYSTEM USING 2D-DCT
In digital network systems the digital documents can be replicated and pass on effortlessly to extensive individuals with ease and free of cost. Multimedia data like image, video and audio files can be easily downloaded by public and they can easily manipulates. The approved proof as a steady and robust watermark should have been embedded in the digital pictures. The proposed work aims at developing a robust digital watermarking system, it incorporates an effective watermarking algorithm which solves the above problem. New blind frequency watermarking algorithm using 2-Dimensional Discrete Cosine Transform and 1-Dimensional Walsh vectors has been proposed
âTo Know the Scoreâ - A Critical Analysis on the Shift of Workplace Culture Created by the Pandemic and Its Influence on Conflict Management and Employee Morale in Corporates in South India
The pandemic has made organisations abandon the fundamental working premises and has drastically altered the work culture affecting significant shifts in the workplace and subsequently influencing a redesigning of the organisational culture, conflict resolutions and management. The paper explores and critically examines the work conditions viewed from within the context of the global pandemic and discusses the relationship between the employeesâ morale and the conflict crisis in manufacturing companies in South India with specific elaborations on the meaning of conflict management, workersâ morale, causes and effects of the shift in the workplace and conflict resolution. With specific reference to corporate organisations in Chennai and Bengaluru, the study analyses through a qualitative methodology how organisations get ravaged by one form of conflict or the other ranging from intrapersonal and group conflict, intra-organisational cultural conflict, constructive or functional conflict, dysfunctional or destructive conflicts. The survey indicated that conflicts occur in organisations as a result of incompatible goals, different values and beliefs, inconsistent evaluation, communication problems, negative power politics, authority, lack of leadership style, scarcity of common resources and organisational demands. It was also found that if conflicts are not appropriately and promptly managed, it can lead to truncated or reduced workersâ morale. The discussion leads to findings which indicate that the workplace as we know it is forever changed by the lockdowns owing to the pandemic. Management and leadership of organisations should begin to take steps to consider redesigning the workplace to readdress the working conditions with innovation and aim to develop better co-relationship between organisations and employees within the virtual platform. What are the ways in which employeesâ morale can be positively uplifted during an organisational conflict on a virtual working mode? How do innovative digital operations improve the standard of an organisation? What may be the conflict resolutions that can bring about a positive shift in the workplace for the future owing to the phenomenal disruption caused by the Pandemic? These and other related questions will be raised and addressed in the course of the discussion. The study was initially intended for working employees as the target readership. The scope of this research may further be extended and can prove to be beneficial for further research on Human Resource and Management Studies.
Keywords: Workplace Culture, Conflict Management, Employee Morale, Pandemi
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