ABSTRACT
Introduction: Mucormycosis is an angio-invasive fungal infection that increased significantly during the 2nd wave of the Covid-19 pandemic in India. The rise of cases was attributed to inflammatory changes, poor quality oxygen, immune suppression, and corticosteroid therapy. Case Presentation: This case study reports the history, treatment, and rehabilitation of a case of post-Covid-19 mucormycosis infection. The patient was admitted to the hospital following respiratory distress, at the beginning of the 2nd Covid-19 wave in India. Intravenous antibiotics, steroids, and moist O2 were administered, intensive support was provided and the patient was discharged after 13 days. Following extraction of 17, the patient reported signs of oro-antral communication which was managed by performing antral lavage and buccal advanced flap closure. Histopathological investigation of tissue salvaged during the procedure revealed the presence of fungal hyphae. Management and Prognosis: Following diagnosis, anti-fungal medication was prescribed, and a maxillectomy was performed to remove the affected tissue. On follow-up, the tissue healed with no further complications or symptoms, and rehabilitation was performed using an obturators and are movable complete denture. Histopathological investigations were carried out on the tissue salvaged during maxillectomy which confirmed Mucormycosis infection. Conclusion: The importance of histopathological investigation in the diagnosis of any infectious disease is enumerated in this paper
ABSTRACT
In theory, enrichment of resource in a predator-prey model leads to destabilization of the system,thereby collapsing the trophic interaction,a phenomenon referred to as "the paradox of enrichment". After it was first pro posed by Rosenzweig (1971), a number of subsequent studies were carried out on this dilemma over many decades. In this article, we review these theoretical and experimental works and give a brief overview of the proposed solutions to the paradox. The mechanisms that have been discussed are modifications of simple predator -prey models in the presence of prey that is inedible, invulnerable, unpalatable and toxic. Another class of mechanisms includes an incorporation of a ratio-dependent functional form,inducible defence of prey and density-dependent mortality of the predator. Moreover, we find a third set of explanations based on complex population dynamics including chaos in space and time. We conclude that,although any one of the various mechanisms proposed so far might potentially prevent destabilization of the predator-prey dynamics following enrichment, in nature different mechanisms may combine to cause stability, even when a system is enriched. The exact mechanisms,which may differ among systems,need to be disentangled through extensive field studies and laboratory experiments coupled with realistic theoretical models.
Subject(s)
Food Chain , Models, Theoretical , Population Density , Population Dynamics , Systems Biology/methodsABSTRACT
Exploitation of biological resources and the harvest of population species are commonly practiced in fisheries, forestry and wild life management. Estimation of maximum harvesting effort has a great impact on the economics of fisheries and other bio-resources. The present paper deals with the problem of a bioeconomic fishery model under environmental variability. A technique for finding the maximum harvesting effort in fluctuating environment has been developed in a two-species competitive system, which shows that under realistic environmental variability the maximum harvesting effort is less than what is estimated in the deterministic model. This method also enables us to find out the safe regions in the parametric space for which the chance of extinction of the species is minimized. A real life fishery problem has been considered to obtain the inaccessible parameters of the system in a systematic way. Such studies may help resource managers to get an idea for controlling the system.