Dough aeration and rheology: Part 1. Effects of mixing speed and headspace pressure on mechanical development of bread dough

A laboratory‐scale Tweedy‐type mechanical dough development mixer was modified to monitor work inputs of dough during mixing through a computerised data acquisition system. Recorded torque showed a curve that increased to a peak about midway through mixing. Using this system, the effects of mixing speed and pressure on the development of doughs made from strong and weak flours mixed to a work input of 40 kJ kg⁻¹ were studied. Mixing was characterized in terms of peak torque and torque at the end of mixing (end torque), and in terms of the number of blade revolutions at these two reference points. The peak torque and the end torque both increased with increasing mixing speed. The peak torque increased with increasing mixer headspace pressure, but the end torque did not. The number of blade revolutions to both the point of peak torque and to the end of mixing decreased with increasing mixing speed for both flours, implying dough development at higher speeds was more efficient. Increasing headspace pressure reduced the number of revolutions to the peak, but not to the end of mixing. These results provide evidence that achieving dough development is not independent of mixing speed in Tweedy‐type mixers, and that dough aeration, as affected by mixer headspace pressure, affects dough rheology and hence development in the mixer. Copyright © 2005 Society of Chemical Industry     

Real-time acquisition and data analysis of skeletal muscle contraction in a multi-user environment

A data acquisition system is described which acquires data from contracting skeletal muscle. The system is designed to run in a multi-user environment while acquiring contractile data in real-time. Time dedicated solely to laboratory experiments is thus eliminated. A menu-driver is included to allow users to enter experimental commands with or without command arguments. Error monitoring functions prevent operator errors from causing data loss. Data storage in both ASCII and binary formats maximizes file flexibility, readability and accessibility. Finally, an on-line tutorial and help facility is provided for user training. The system developed is applicable to any experimental environment involving data acquisition, storage and analysis.     

Application of a gamma extremity monitoring system in a radiopharmaceutical dispensary

Cell-mediated immunity and cytokines are probably involved in the pathogenesis of malaria. To investigate the role and the activity of different immune cells, we measured levels of tumour necrosis factor-(TNF-alpha), gamma interferon (IFN-gamma) and several interleukins (IL-2, IL-4, IL-6 and IL-10) in children with mild (MM) and cerebral (CM) Plasmodium falciparum malaria and compared them with those of healthy children from Guadalupe--Lobata District, St. Tomé Island, where malaria is mesoendemic. Both groups of patients had significantly higher levels of IL-6, IL-10 and TNF-alpha than controls. For IL-2, IL-4 and IFN-gamma we found no difference between the groups. However, 24 h after admission the levels of IL-10 and IL-6 were significantly higher in CM than in MM patients, although 7 days after treatment they returned to normal levels, similar to those found in control children. Therefore, TNF-alpha IL-6 and IL-10 increase during Plasmodium falciparum attacks in all children, not only in those with cerebral malaria. This finding suggests the activation of the monocyte/macrophage system during the early stage of clinical malaria.     

Risk factors for repeat attendance at hospital emergency departments among adults and children with asthma

Protein phosphorylation is a well-known mechanism by which extracellular molecules or factors transduce their signals into intracellular effects. In the context of myelin assembly, phosphorylation of major myelin proteins affects the electrostatic repulsion between adjacent proteins within myelin structure and therefore constitutes one of the mechanisms by which myelin stability is regulated. We report here that arachidonic acid (AA) decreases the phosphorylation of myelin basic protein (MBP) both in the absence and in the presence of phorbol esters in cultured rat oligodendrocytes (OLGs). The effect of AA on MBP phosphorylation is not mediated by cyclooxygenase products, though the possibility that leukotrienes or other epoxides may have a role cannot be excluded. AA did not act by inactivation of protein kinase C. Based on our findings from gadolinium and low K+ experiments, we conclude that inhibition of MBP phosphorylation is not dependent on AA-induced increases in OLG Ca(i), but rather on its depolarizing action. We have thus demonstrated that a brief exposure to AA, which either acts as a diffusible paracrine signal to OLGs or as a signal transducer, can trigger changes in protein phosphorylation in OLGs/myelin via ionic signaling events at the plasma membrane.     

The Role of Institutional Review Boards in Facilitating Research, Marketing of Drugs and Devices, and Protecting Human Subjects

Concern for outside review of medical research involving human subjects has been documented as far back as the early Nineteenth Century. It was not until 1966, however, when applicants for Public Health Service grant funding were subjected to such a requirement, that researchers were required to undergo review. Institutional Review Boards (IRB) are the bodies charged with performing the mandated screening functions by the Department of Health and Human Services (HHS) for federally funded projects and by the Food and Drug Administration (FDA) in the drug and device approval process.

This paper explores an IRB's responsibilities under the HHS and FDA regulations generally, and emphasizes several critical attendant issues including: the manufacturer's IRB; IRB members' individual liability; compensation for research injuries; civil rights protections afforded subjects; impact upon academic and health practitioner research; and effect upon drug and device approvals.     

Sensor system for monitoring soil moisture content in cable trenches of high-voltage cables

An in-situ moisture sensor intended to measure the moisture content of cable trench filler material is described. The design of the unit, which has been built to integrate with existing data monitoring systems allowing remote interrogation and enabling real-time decisions to be made on circuit loading safety margins, is discussed.