Robotic control in knee joint replacement surgery

A brief history of robotic systems in knee arthroplasty is provided. The place of autonomous robots is then discussed and compared to more recent 'hands-on' robotic systems that can be more cost effective. The case is made for robotic systems to have a clear justification, with improved benefits compared to those from cheaper navigation systems. A number of more recent, smaller, robot systems for knee arthroplasty are also described. A specific example is given of an active constraint medical robot, the ACROBOT system, used in a prospective randomized controlled trial of unicondylar robotic knee arthroplasty in which the robot was compared to conventional surgery. The results of the trial are presented together with a discussion of the need for measures of accuracy to be introduced so that the efficacy of the robotic surgery can be immediately identified, rather than have to wait for a number of years before long-term clinical improvements can be demonstrated.     

ProteinParser--a community based tool for the generation of a detailed protein consensus and FASTA output

Comparison of bioinformatic data is a common application in the life sciences and beyond. In this communication, a novel Java based software tool, ProteinParser, is outlined. This software tool calculates a detailed consensus, or most common, amino acid at a given position in an aligned protein set, whilst also generating a full consensus protein FASTA output. A second application of this software tool, computing a consensus amino acid given a tolerance threshold, is also demonstrated. The phytase and the common bacterial beta-lactamase proteins are analysed as 'proof of concept' examples. Consensus proteins, as generated by ProteinParser, are regularly utilised in the selection of residues for protein stabilisation mutagenesis; however, this widely applicable software tool will find many alternative applications in areas such as protein homology modelling.     

Two methods of natural family planning

I read with interest the recent article by Wade and associates, "A randomized prospective study of the use-effectiveness of 2 methods of natural family planning: an interim report" (134: 628, 1979). In reference to the study of the ovulation method, the authors noted that abstinence begins on the 1st day of mucus secretion and continues until the evening of the 4th day beyond the peak or maximal mucus secretion. In the ovulation method, the peak symptom is not the same as maximal mucus secretion as was indicated in the paper. The peak symptom is defined as the last day of the mucus discharge that is clear and/or stretchy and/or lubricative. In the definition of peak symptom, the amount of mucus discharge is not specifically important and may often be misleading. I had the opportunity to do a site visit at this study at the request of the National Institutes of Health while the study was in progress. I analyzed several pregnancies which occurred in users of this ovulation method. Some of the pregnancies occurred as the result of poor teaching of the concept of peak symptom. In the ovulation method, proper understanding and teaching of that concept are essential to the measurement of its effectiveness. Noticeably missing from this interim report was any discussion of the quality control procedures which were utilized to guarantee a high-quality educational service to the people entered into the study. While the authors claim that the methods were taught by professional teachers, these teachers were actually women who had previously used the method and/or had formalized training in teaching the method. Simple use of either of the methods certainly does not qualify an individual to teach natural family planning. For those with formalized teaching, such training should have been outlined since judgment on the effectiveness of the teaching cannot be made; such a judgment is essential to the proper analysis of results. Finally, while the study claims to be a use-effectiveness study, it is rather a modified version of extended use-effectiveness. No objective definition of "user failure" is provided. One cannot ascertain how many pregnancies were related to poor teaching, nor can one tell how many occurred as the result of the couples' last minute exercise of their freedom to use their fertility. The use-effectiveness of the 2 methods under study as a means to achieve a pregnancy have been ignored. In doing so, the investigators have ignored use-effectiveness reality.     

Relationship between a behavioral and several psychometric measures of test anxiety

Behavioral time-sampling was compared with various paper-and-pencil, self-report measures of test anxiety in an examination of the utility of the behavioral measure as an in situo index of test anxiety. The behavioral measure was significantly and positively correlated 0.45 with a paper-and pencil, self-report measure of "facilitative" test anxiety but not with measures of "debilitative" test anxiety (r = -0.15) or general anxiety (r = -0.33) for 12 males and 21 female undergraduates.     

Diagnosis and epidural hematoma by brain scan and perfusion study: case report

By using the arterial and venous phases of an anterior cerebral perfusion study, which showed downward displacement of the sagittal sinus, and the finding of a "rim" on the delayed scans, the specific diagnosis of epidural hematoma was established.     

Electronic trading and the process of globalization in traditional futures exchanges: a temporal perspective

This paper develops a temporal perspective to examine information and communication technologies (ICT) adoption and processes of globalization. The foundations of our theoretical approach explicitly draw upon three intersecting planes of temporality implicit in structuration; namely reversibility, irreversibility and institutionalization. We further develop our theoretical perspective by extending the scope of structuration to incorporate temporal features of Adam's social theory on ‘global time’. We then use this temporal perspective to examine the emergence of electronic trading and the process of globalization across London and Chicago futures exchanges. Our analysis provides insights into the IT-enabled reconfiguration of these exchanges during processes of reproduction and change associated with globalization. We conclude with some key implications for e-trading strategy and consider changes in trader work life associated with the adoption of e-trading.     

Surface analysis using a new plasma assisted desorption/ionisation source for mass spectrometry in ambient air

The authors report on a modified micro-plasma assisted desorption/ionisation (PADI) device which creates plasma through the breakdown of ambient air rather than utilising an independent noble gas flow. This new micro-PADI device is used as an ion source for ambient mass spectrometry to analyse species released from the surfaces of polytetrafluoroethylene, and generic ibuprofen and paracetamol tablets through remote activation of the surface by the plasma. The mass spectra from these surfaces compare favourably to those produced by a PADI device constructed using an earlier design and confirm that the new ion source is an effective device which can be used to achieve ambient mass spectrometry with improved spatial resolution.     

The Blocking of Integrin-Mediated Interactions with Maternal Endothelial Cells Reversed the Endothelial Cell Dysfunction Induced by EVs,Derived from Preeclamptic Placentae

Placental extracellular vesicles (EVs) have increasingly been recognized as a major mediator of feto-maternal communication. However, the cellular and molecular mechanisms of the uptake of placental EVs by recipient cells are still not well-understood. We previously reported that placental EVs target a limited number of organs in vivo. In the current study, we investigated the mechanisms underlying the uptake of placental EVs into target cells. Placental EVs were derived from explant cultures of normal or preeclamptic placentae. The mechanisms underlying the uptake of placental EVs were elucidated, using the phagocytosis or endocytosis inhibitor, trypsin-treatment or integrin-blocking peptides. The endothelial cell activation was studied using the monocyte adhesion assay after the preeclamptic EVs exposure, with and/or without treatment with the integrin blocking peptide, YIGSR. The cellular mechanism of the uptake of the placental EVs was time, concentration and energy-dependent and both the phagocytosis and endocytosis were involved in this process. Additionally, proteins on the surface of the placental EVs, including integrins, were involved in the EV uptake process. Furthermore, inhibiting the uptake of preeclamptic EVs with YIGSR, reduced the endothelial cell activation. The interaction between the placental EVs and the recipient cells is mediated by integrins, and the cellular uptake is mediated by a combination of both phagocytosis and endocytosis.     

Detection of endogenous Snf1 and its activation state: application to Saccharomyces and Candida species

The stress-response Snf1 protein kinase of Saccharomyces cerevisiae serves as a powerful model for studies of the eukaryotic Snf1/AMP-activated protein kinase (AMPK) family. Central to studies of Snf1 are methods that determine its activation state under various physiological and genetic conditions. Here, we have developed a convenient and sensitive method for immunoblot analysis of endogenous yeast Snf1 and its activation-loop threonine (Thr210) phosphorylation. The method employs readily obtainable reagents and yields results that faithfully reflect the environmental and genetic conditions tested. Using our method, we have obtained evidence that Snf1 remains stress-regulated in reg1 Delta cells, revealing the existence of a Snf1 signalling mechanism(s) that is independent of Reg1-PP1 phosphatase. In addition to strains of common laboratory S. cerevisiae backgrounds, we have applied the method to two pathogenic Candida species, C. glabrata and C. albicans. We have detected proteins whose gel mobilities, immune properties and regulation patterns are consistent with those expected for the corresponding Snf1 homologues. Because Snf1 activation is a sensitive marker of several types of stress, including artifactual stresses associated with common cell harvesting and protein extraction procedures, the convenient and efficient protein extraction method described here should be advantageous for SDS-PAGE and immunoblot analyses of stress-regulated and other proteins from various yeast species.     

Hydraulic Model for Sedimentation in Storm-Water Detention Basins

Treatment of storm-water runoff may be necessary before discharge to surface waters. In urban areas, space constraints limit selection of conventional treatment systems, and alternative systems are needed. This research program involves design and laboratory testing of a small footprint nonproprietary detention basin which consists of pipes and box culvert sections with a specialized inlet and outlet system. This system can be placed below grade near the roadway section as part of the conventional drainage system and does not require additional right-of-way. A mathematical model, based entirely on hydraulic principles, is developed to estimate particle removal efficiency of the rectangular detention basin for the treatment of storm-water runoff by extending ideal horizontal tank theory under the condition in which water level is varied. A physical model was built in 1/5 scale to measure particle removal performance and validates the conceptual model. Experiments were performed for steady inflow conditions with different inflow rates, durations, and suspended sediment concentrations. Measured time series outflow suspended sediment concentrations and particle removal efficiency compare well with calculated results from the conceptual model. The outflow particle-size distribution can also be estimated using the conceptual model.