3,582 research outputs found
Studies on selected biological parameters off Mithapur (Gujarat)
The biological characteristics off Mithapur, India, indicated fairly high productivity in terms of macrobenthos and phytoplankton pigment concentration. The area sustained low standing stock of zooplankton. The overall biological productivity of plankton and macrobenthos indicated 30-90% reduction from the premonsoon to postmonsoon period. This decline in the standing stock of plankton and benthos was coinciding with the peak fishing season of the area
Proceedings of the Second workshop on scientific results of FORV Sagar Sampada
Since inception in 1984, the Fisheries and Oceanographic Research Vessel
Sagar Sampada, with sophisticated modern facilities onboard, has undertaken more
than 140 cruises all over the Indian Ocean primarily in our Exclusive Economic Zone
for fishery and oceanographic survey. Scientists from many institutions have made
use of this facility to explore the resource potential in our sea and to understand its
correlation with the environmental parameters. These survey and exploration efforts
are continuing.
This volume contains many papers which are the outcome of research work carried
out onboard 'Sagar Sampada' during last five years (1989-1993) and presented in a
Workshop to evaluate the scientific work. About 60 papers, included in this volume,
bring out the results pertaining to environmental assessment, hydrology, productivity
estimates, fishery resources availability, fishing technology, pollution monitoring etc.
These relate mainly to the Arabian Sea, Bay of Bengal and Lakshadweep, Andaman
and Nicobar Islands groups in the EEZ of India. These efforts along with other
mission-oriented cruises have yielded valuable information on the fishery resources
and their distribution in space and time
On the discrete adaptive posicast controller
In this paper, we present the discrete version of the Adaptive Posicast Controller (APC) that deals with parametric uncertainties in systems with input time-delays. The continuous-time APC is based on the Smith Predictor and Finite Spectrum Assignment with time-varying parameters adjusted online. Although the continuous-time APC showed dramatic performance improvements in experimental studies with internal combustion engines, the full benefits could not be realized since the finite integral term in the control law had to be approximated in computer implementation. It is shown in the literature that integral approximation in time-delay compensating controllers degrades the performance if care is not taken. In this work, we present a development of the APC in the discrete-time domain, eliminating the need for approximation. In essence, this paper attempts to present a unified development of the discrete-time APC for systems that are linear with known/unknown input time-delays. Performances of the continuous-time and discrete-time APC, as well as conventional Model Reference Adaptive Controller (MRAC) for linear systems with known time-delay are compared in simulation studies. It is shown that discrete-time APC outperforms its continuoustime counterpart and MRAC. Further simulations studies are also presented to show the performance of the design for systems with uncertain time-delay. © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved
Fibrosarcome du larynx - A propos d'un cas
Le fibrosarcome du larynx est une entité histologique rare, qui représente moins de 10% de tous les sarcomes des tissus mous, moins de 2 % des cancers laryngés. Cette localisation pose des problèmes diagnostique, thérapeutique et pronostique. Nous présentons un cas de fibrosarcome laryngé chez un patient de 54 ans. La confirmation histologique etimmunohistologique a été faite sur la pièce d’exérèse chirurgicale et surtout sur une confrontation anatomoclinique. La prise en charge thérapeutique est multidisciplinaire, associant la chirurgie qui doit être la plus complète sans curage ganglionnaire et la radiothérapie. Le pronostic est généralement sévère, dépend essentiellement de degré de différenciation histologique.Mots clés : fibrosarcome ; larynx ; chirurgie ; radiothérapie
Control of Uncertain Sampled-Data Systems: An Adaptive Posicast Control Approach
This technical note proposes a discrete-time adaptive controller for the control of sampled-data systems. The design is inspired from the Adaptive Posicast Controller (APC) which was designed for time-delay systems in continuous time. Due to the performance degradation caused by digital approximation of continuous laws, together with the problem of assuming time-delays as integer multiples of sampling intervals, the benefits of APC could not be fully realized. In this technical note, these approximations/assumptions are eliminated. In addition, a disturbance observer is incorporated into the controller design which minimizes the effect of disturbances on the system. Extension to the case of uncertain input time-delay is also presented. The proposed approach is verified in simulation studies. © 1963-2012 IEEE
Drug resistance profile and biofilm forming potential of Pseudomonas aeruginosa isolated from contact lenses in Karachi-Pakistan
BACKGROUND: The contaminated contact lens provides Pseudomonas aeruginosa an ideal site for attachment and biofilm production. Continuous contact of the eye to the biofilm-infested lens can lead to serious ocular diseases, such as keratitis (corneal ulcers). The biofilms also prevent effective penetration of the antibiotics, which increase the chances of antibiotic resistance. METHODS: For this study, 22 Pseudomonas aeruginosa isolates were obtained from 36 contact lenses and 14 contact lens protective fluid samples. These isolates were tested against eight commonly used antibiotics using Kirby-Bauer disk diffusion method. The biofilm forming potential of these isolates was also evaluated using various qualitative and quantitative techniques. Finally, a relationship between biofilm formation and antibiotic resistance was also examined. RESULTS: The isolates of Pseudomonas aeruginosa tested were found resistant to most of the antibiotics tested. Qualitative and quantitative biofilm analysis revealed that most of the isolates exhibited strong biofilm production. The biofilm production was significantly higher in isolates that were multi-drug resistant (p < 0.0001). CONCLUSION: Our study indicates that multi-drug resistant, biofilm forming Pseudomonas aeruginosa isolates are mainly involved in contact lens associated infections. This appears to be the first report from Pakistan, which analyzes both antibiotic resistance profile and biofilm forming potential of Pseudomonas aeruginosa isolates from contact lens of the patients with contact lens associated infections
Controlling for openness in the male-dominated collaborative networks of the global film industry.
Studies of gender inequality in film industries have noted the persistence of male domination in creative roles (usually defined as director, producer, writer) and the slow pace of reform. Typical policy remedies are premised on aggregate counts of women as a proportion of overall industry participation. Network science offers an alternative way of identifying and proposing change mechanisms, as it puts emphasis on relationships instead of individuals. Preliminary work on applying network analysis to understand inequality in the film industry has been undertaken. However, in this study we offer a comprehensive approach that enables us to not only understand what inequality in the film industry looks like through the lens of network science but also how we can attempt to address this issue. We offer a data-driven simulation framework that investigates various what-if scenarios when it comes to network evolution. We then assess each of these scenarios with respect to its potential to address gender inequality in the film industry. As suggested by previous studies, inequality is exacerbated when industry networks are most closed. We review evidence from three different national film industries on network relationships in creative teams and identify a high proportion of men who only work with other men. In response to this observation, we test several mechanisms through which industry structures may generate higher levels of openness. Our results reveal that the most critical factor for improving network openness is not simply the statistical improvement of the number of women in a network, nor the removal of men who do not work with women. The most likely behavioural changes to a network will involve the production of connections between women and powerful men
System measure for persistence in holographic recording and application to singly-doped and doubly-doped lithium niobate
We define a measure for persistence in holographic recording. Using this measure and the known measures for dynamic range and sensitivity, we compare the performance of singly-doped and doubly-doped LiNbO3 crystals. We show that the range of performance that can be obtained using doubly-doped crystals is much larger than that obtained using singly-doped ones. (C) 2001 Optical Society of America
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