148 research outputs found
Observation of Live Ticks (Haemaphysalis flava) by Scanning Electron Microscopy under High Vacuum Pressure
Scanning electron microscopes (SEM), which image sample surfaces by scanning with an electron beam, are widely used for steric observations of resting samples in basic and applied biology. Various conventional methods exist for SEM sample preparation. However, conventional SEM is not a good tool to observe living organisms because of the associated exposure to high vacuum pressure and electron beam radiation. Here we attempted SEM observations of live ticks. During 1.5Ă10â3 Pa vacuum pressure and electron beam irradiation with accelerated voltages (2â5 kV), many ticks remained alive and moved their legs. After 30-min observation, we removed the ticks from the SEM stage; they could walk actively under atmospheric pressure. When we tested 20 ticks (8 female adults and 12 nymphs), they survived for two days after SEM observation. These results indicate the resistance of ticks against SEM observation. Our second survival test showed that the electron beam, not vacuum conditions, results in tick death. Moreover, we describe the reaction of their legs to electron beam exposure. These findings open the new possibility of SEM observation of living organisms and showed the resistance of living ticks to vacuum condition in SEM. These data also indicate, for the first time, the usefulness of tick as a model system for biology under extreme condition
Development of crystalline inclusions (âergosterol crystalsâ) in Neurospora crassa
Development of crystalline inclusions (âergosterol crystalsâ) in âsnowflakeâ, a morphological mutant of Neurospora crassa has been examined. The inclusions which arise in membranebound organelles appear as electron dense deposits, increase in size, and occupy nearly all the space within the organelle at maturity. The presence of catalase activity in the organelle was not detected using cytochemical procedures employing diaminobenzidine.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41731/1/709_2005_Article_BF01275681.pd
The doctoral studies paradox: Indigenous cultural paradigms versus Western-based research practices
This is an exploratory conceptual paper regarding the ontological and epistemological premises that are present in the enrollment of Indigenous peoples in doctoral programs at higher education institutions (HEIs). The paradoxical nature of navigating through distinct points-of-view about two distinct cultural perspectives, that of the doctorate representing a culminating recognition of a professional culture based on Western tradition and the norms and values of Indigenous cultures. There are personal risks involved in undergoing an education predicated on conflicting messages paradoxes represent from prior personal and collective experience and from institutional dicta and expectations. This paper looks at how an individual brings these elements together in a transformative manner that accepts or rejects governmental preference for enhanced participation by Indigenous peoples in doctoral education programs
Antiproliferative effects of masitinib and imatinib against canine oral fibrosarcoma in vitro
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