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Biomedical subjects

G Roth

Publications and source records attributed to G Roth.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

Monitoring adenovirus infections with on-line and off-line methods.

Several known process monitoring methods were tested for their efficacy in the detection of adenovirus infections. The methods that we explored include several indirect indications of viral infections, including metabolic rate analysis, secondary gauges of respiration, cell size measurement, cell number and cell viability determination, and changes in capacitance. Direct indications of the adenovirus infection were also applied, including total viral particle and infectious particle measurements, as well as a flow cytometry method for detecting infected cells. All of the methods tested in the study provide some positive indication of an adenovirus infection. Many of the methods require repeated sampling, which may limit their utility in a manufacturing process. All of the indirect measures of viral infection may be limited by the fact that they do not uniquely identify an infection. The simplest monitoring methods appear to be detection of changes in respiration or the capacitance of the culture, both of which seem to provide a clear indication of an infection. Further work will be required to demonstrate that these indications are characteristic of only a successful and productive adenovirus infection.

Adenoviridae↗
PubMedDate not supplied

The role of eye accommodation in the depth perception of common toads.

Distance estimation in prey catching was as exact in monocular toads (Bufo bufo (L.)) as in binocular ones. Application of Atropine or Miotic had no significant effect on binocular animals, whereas in monocular toads it made accurate distance estimation impossible. The accommodative state of the eye is decisive for depth estimation of monocular, but not of binocular toads.

Accommodation, Ocular↗
PubMedDate not supplied

How to make experience your company's best teacher.

In our personal life, experience is often the best teacher. Not so in corporate life. After a major event--a product failure, a downsizing crisis, or a merger--many companies stumble along, oblivious to the lessons of the past. Mistakes get repeated, but smart decisions do not. Most important, the old ways of thinking are never discussed, so they are still in place to spawn new mishaps. Individuals will often tell you that they understand what went wrong (or right). Yet their insights are rarely shared openly. And they are analyzed and internalized by the company even less frequently. Why? Because managers have few tools with which to capture institutional experience, disseminate its lessons, and translate them into effective action. In an effort to solve this problem, a group of social scientists, business managers, and journalists at MIT have developed and tested a tool called the learning history. It is a written narrative of a company's recent critical event, nearly all of it presented in two columns. In one column, relevant episodes are described by the people who took part in them, were affected by them, or observed them. In the other, learning historians--trained outsiders and knowledgeable insiders--identify recurrent themes in the narrative, pose questions, and raise "undiscussable" issues. The learning history forms the basis for group discussions, both for those involved in the event and for others who also might learn from it. The authors believe that this tool--based on the ancient practice of community storytelling--can build trust, raise important issues, transfer knowledge from one part of a company to another, and help build a body of generalizable knowledge about management.

Communication↗
PubMedDate not supplied

Identification of motor conduction block despite desynchronisation. A method.

Identification of incomplete motor conduction block (CB) by the usual single stimulation method is problematic when impaired conduction velocity of the axons spared by the block exists at the site of the presumed CB, leading to desynchronisation. Indeed, the area of the compound muscle action potential (MAP) evoked by stimulation applied above this site may be reduced by the phase cancellation related to desynchronisation. A triple stimulation method with double collisions allows virtual displacement of the CB distally to the site where desynchronisation occurs. A first stimulus applied on the nerve above the site of the CB is followed--after a delay--by a stimulation applied distally on the nerve where a collision occurs. This collision, however, does not concern the antidromic wave of the blocked axons which travels towards the block. A third stimulus is then applied--after a second delay--below the site of the CB, where a second collision occurs in the blocked axons. Thus, the third stimulus evokes a MAP that concerns only the unblocked axons, as would the stimulus applied above the site of the CB. In this manner, desynchronisation occurring at the CB site is avoided. The method was developed on simulated CBs of the ulnar nerve at the elbow of 33 normal subjects and compared with the usual single stimulation method. Subsequently, it was evaluated on 8 pathological CBs of the ulnar nerve at the elbow and of the peroneal nerve at the fibular head. The method detects CBs of 5% or more despite the occurrence of desynchronisation.

Action Potentials↗