A Model To Measure Supination And Pronation Of The Foot Over Different Levels Of Physiological Stress Using An In-Shoe Force Monitoring System

The purpose of this study was to create a diagnostic model of supination and pronation of the foot using vertical ground reaction forces. A size adjustable capacitive transducer retaining 960 individual pressure cells was used to assess orthopaedic parameters of gait cyale timing and vertical ground reaction forces. A pilot sample of five males were used for this model. The subjects were exposed to six experimental conditions. These being; a) a walk, b) jog, c) walk on treadmill, and d) three levels of perceived exertion (mild, moderate and hard running). Perceived exertion was measured with the Borg (RPE) scale. All subjects were measured in the same brand of athletic shoe to control for intershoe differences. The ptonation/supination model was determined by medial/lateral force and timing measurements of the calcaneus, forefoot prominence, arch, the first and fifth metatarsal heads and the toe off (end of gait cycle). Results indicated bi-Iateral differences in the medial and lateral force measurements of the calcaneus. Timing in this area was slightly different. Medial to lateral timing pronation was evidenced in the treadmill walking and moderate running condition. As well, the loading of the first and fifth metatarsal heads as a percentage of the gait cycle did not change over the running conditions. The preliminary results of five subjects provides for limited support of a vertical ground reaction model to assess pronation and supination. Further research with techniques such as high speed photography will allow for clarification of this model

DYNAMIC MEASUREMENT OF FORCE WITHIN THE SHOE DURING CONDITIONS OF PERCEIVED EXERTION

INTRODUCTION Athletics and recreation are becoming a very large component of modem day society. Now, more than ever, more people are becoming very active and involved in recreational pursuits that include aerobics and running/jogging. The resultant increase in activity has lead to a noted increase in injuries (Nigg, 1985; Mckenzie et al., 1985). James et al (cited in Cavanagh, 1990), in a study of 180 injured runners identified three categories of running injury problem areas. These areas being: a) training errors; b)anatomic factors (biomechanics); and c) shoes and surfaces. Two thirds of these injuries were accounted for by training errors (increased mileage or increased intensity). Training errors concerning sudden increases in mileage or intensity tend to subject the body to new or greater than expected physiological stressors. Voloshin and Wosk (1981), have investigated the relationship between heel strike shock wave transmission and joint degeneration in walking subjects. Taken one step further, the implications of damage to the muscle-skeletal system by running is noted by Cavanagh (1990). This combined with the Nigg et al. (1983) data that suggests a relationship between the hardness of the athletic (running) surface and the incidence of injury has serious implications for the recreational runner/athlete. Clarke et al. (1985) have highlighted the possible injurious force involved in tibial accelerations that are the result of the runner taking longer strides. Since most people retain a constant stride frequency, as velocity increases, the athlete tends to increase their stride length. The resultant increase in stride length increases impact forces at the joint. This combined with the increase of ground reaction forces with higher running speeds (Munro et al., 1987) identifies high impact forces as a major factor to be considered when investigating the causal nature of running injuries. Research into the type of shoe and ground reaction forces has been equivocal. Nigg and Bahlsen (1988) have stated that shoes with the hardest mid soles elicit the lowest maximal vertical forces. Conversely other research has indicated that shoe hardness is related to higher (vertical) loading rates. Listed above are a number of factors involved in the prediction of running injuries. Further research is needed to discover the causative factors involved in etiology of sport medicine running injuries. An analysis of running shoes, in particular the vertical ground reaction forces, may account for dynamic patterns of gait. Running at different levels of perceived exertion may elicit clues as to the biomechanics patterns that may be injurious to runners. For example, the gait of a runner at the beginning of the run may be markedly different from the gait at the end of the run. Variables such as intensity and distance will greatly affect the athlete's form as they become more tired. Thus, the number of running injuries (2/3 of Clarke's population) as a result of improper training may be the function of bad form (gait mechanics). An analysis under different levels of exertion will identify patterns of pressure with the foot that may have implications for the construction and design of athletic footwear as well as training methods for runners. This study was an attempt to understand the dynamic of in-shoe vertical ground reaction forces within the shoe under differing levels of perceived exertion. Research in the area of running shoe forces may lead to the development of a better product that will decrease the rate and type of running injuries

fMRI Randomized Study of Mental and Motor Task Performance and Cortisol Levels to Potentiate Cortisol as a New Diagnostic Biomarker.

Cortisol is an important hormone in the protective stress response system, the Hypothalamus-Pituitary-Adrenal (HPA axis). It becomes especially salient in immune suppression syndromes such as multiple sclerosis and Cushing’s disease. Fatigue is a common symptom and mental and motor tasks are difficult and labored. The role of cortisol is mental and motor tasks and the recruitment of key brain regions in completion of these tasks is explored together with functional magnetic resonance imaging in healthy participants. Cortisol levels were found to be higher and had greater reduction in levels during mental versus motor tasks. Recruitment of brain stem and hypothalamus regions, important in cortisol activity, was affected differently. At low cortisol levels, mental task participants had less activity in the regions than their physical task counterparts. When cortisol levels were higher, widerspread recruitment of these brain regions was seen in the mental task participants, and for the physical task participants, the spread was at comparative low levels of cortisol. It is concluded that cortisol is implicated in these brain regions supporting the Thompson Cortisol Hypothesis and that brain region recruitment is likely to be dependent upon factors including cortisol levels as well as perception of stress in the task. It is suggested that mental tasks are perceived more stressful than physical but demand higher cortisol levels to promote wider spread brain region activity. Implication for neurological disease includes the use of cortisol in the proposed development of a potential new diagnostic biomarker for early detection of neurological sequelae

Multiplexed, High Density Electrophysiology with Nanofabricated Neural Probes

Extracellular electrode arrays can reveal the neuronal network correlates of behavior with single-cell, single-spike, and sub-millisecond resolution. However, implantable electrodes are inherently invasive, and efforts to scale up the number and density of recording sites must compromise on device size in order to connect the electrodes. Here, we report on silicon-based neural probes employing nanofabricated, high-density electrical leads. Furthermore, we address the challenge of reading out multichannel data with an application-specific integrated circuit (ASIC) performing signal amplification, band-pass filtering, and multiplexing functions. We demonstrate high spatial resolution extracellular measurements with a fully integrated, low noise 64-channel system weighing just 330 mg. The on-chip multiplexers make possible recordings with substantially fewer external wires than the number of input channels. By combining nanofabricated probes with ASICs we have implemented a system for performing large-scale, high-density electrophysiology in small, freely behaving animals that is both minimally invasive and highly scalable

Development of the Bélanger Equation and Backwater Equation by Jean-Baptiste Bélanger (1828)

A hydraulic jump is the sudden transition from a high-velocity to a low-velocity open channel flow. The application of the momentum principle to the hydraulic jump is commonly called the Bélanger equation, but few know that Bélanger's (1828) treatise was focused on the study of gradually varied open channel flows. Further, although Bélanger understood the rapidly-varied nature of the jump flow, he applied incorrectly the Bernoulli principle in 1828, and corrected his approach 10 years later. In 1828, his true originality lay in the successful development of the backwater equation for steady, one-dimensional gradually-varied flows in an open channel, together with the introduction of the step method, distance calculated from depth, and the concept of critical flow conditions

Maximal care considerations when treating patients with end-stage heart failure: ethical and procedural quandaries in management of the very sick

Deciding who should receive maximal technological treatment options and who should not represents an ethical, moral, psychological and medico-legal challenge for health care providers. Especially in patients with chronic heart failure, the ethical and medico-legal issues associated with providing maximal possible care or withholding the same are coming to the forefront. Procedures, such as cardiac transplantation, have strict criteria for adequate candidacy. These criteria for subsequent listing are based on clinical outcome data but also reflect the reality of organ shortage. Lack of compliance and non-adherence to lifestyle changes represent relative contraindications to heart transplant candidacy. Mechanical circulatory support therapy using ventricular assist devices is becoming a more prominent therapeutic option for patients with end-stage heart failure who are not candidates for transplantation, which also requires strict criteria to enable beneficial outcome for the patient. Physicians need to critically reflect that in many cases, the patient’s best interest might not always mean pursuing maximal technological options available. This article reflects on the multitude of critical issues that health care providers have to face while caring for patients with end-stage heart failure

Complex consequences of Cantu syndrome SUR2 variant R1154Q in genetically modified mice

Cantu syndrome (CS) is caused by gain-of-function (GOF) mutations in pore-forming (Kir6.1, KCNJ8) and accessory (SUR2, ABCC9) ATP-sensitive potassium (KATP) channel subunits, the most common mutations being SUR2[R1154Q] and SUR2[R1154W], carried by approximately 30% of patients. We used CRISPR/Cas9 genome engineering to introduce the equivalent of the human SUR2[R1154Q] mutation into the mouse ABCC9 gene. Along with minimal CS disease features, R1154Q cardiomyocytes and vascular smooth muscle showed much lower KATP current density and pinacidil activation than WT cells. Almost complete loss of SUR2-dependent protein and KATP in homozygous R1154Q ventricles revealed underlying diazoxide-sensitive SUR1-dependent KATP channel activity. Surprisingly, sequencing of SUR2 cDNA revealed 2 distinct transcripts, one encoding full-length SUR2 protein; and the other with an in-frame deletion of 93 bases (corresponding to 31 amino acids encoded by exon 28) that was present in approximately 40% and approximately 90% of transcripts from hetero- and homozygous R1154Q tissues, respectively. Recombinant expression of SUR2A protein lacking exon 28 resulted in nonfunctional channels. CS tissue from SUR2[R1154Q] mice and human induced pluripotent stem cell-derived (hiPSC-derived) cardiomyocytes showed only full-length SUR2 transcripts, although further studies will be required in order to fully test whether SUR2[R1154Q] or other CS mutations might result in aberrant splicing and variable expressivity of disease features in human CS

Challenges in optics for Extremely Large Telescope instrumentation

We describe and summarize the optical challenges for future instrumentation for Extremely Large Telescopes (ELTs). Knowing the complex instrumental requirements is crucial for the successful design of 30-60m aperture telescopes. After all, the success of ELTs will heavily rely on its instrumentation and this, in turn, will depend on the ability to produce large and ultra-precise optical components like light-weight mirrors, aspheric lenses, segmented filters, and large gratings. New materials and manufacturing processes are currently under study, both at research institutes and in industry. In the present paper, we report on its progress with particular emphasize on volume-phase-holographic gratings, photochromic materials, sintered silicon-carbide mirrors, ion-beam figuring, ultra-precision surfaces, and free-form optics. All are promising technologies opening new degrees of freedom to optical designers. New optronic-mechanical systems will enable efficient use of the very large focal planes. We also provide exploratory descriptions of "old" and "new" optical technologies together with suggestions to instrument designers to overcome some of the challenges placed by ELT instrumentation.Comment: (Proc. OPTICON Key Technology Network Workshop, Rome 20-21 October 2005

Evidence for insertional codemixing: mixed compounds and French nominal groups in Brussels Dutch

In this paper we analyse mixed compounds, such as legume+winkel ‘vegetable shop, greengrocery’ and winter+paletot ‘winter coat’ which contain a French and a Dutch element, and French nominal groups, such as carte d’identité ‘identity card’, and journal parlé ‘radio news’, which bilingual speakers from Brussels frequently insert into Brussels Dutch utterances. Using Muysken’s (2000) typology of bilingual speech, we claim that the mixed compounds and the nominal groups display the characteristics of insertional code-mixing. In addition, some evidence for the existence of a continuum between borrowing and code-switching can be obtained from these examples. As the multimorphemic units that are inserted into Dutch are neither single words, nor full constituents, their status in the lexicon raises interesting issues for researchers interested in the interface between syntax and the lexicon (see also Backus 2003). We try to argue that nominal groups such as carte d’identité and journal parlé are probably best seen as lexical templates or constructional idioms (Booij, 2002b). The insertion of French constructional idioms in Brussels Dutch represents an innovation in the lexical patterns that are available to speakers of this language, which is highly relevant for theories of language change

Advances in small lasers

M.T.H was supported by an Australian Research council Future Fellowship research grant for this work. M.C.G. is grateful to the Scottish Funding Council (via SUPA) for financial support.Small lasers have dimensions or modes sizes close to or smaller than the wavelength of emitted light. In recent years there has been significant progress towards reducing the size and improving the characteristics of these devices. This work has been led primarily by the innovative use of new materials and cavity designs. This Review summarizes some of the latest developments, particularly in metallic and plasmonic lasers, improvements in small dielectric lasers, and the emerging area of small bio-compatible or bio-derived lasers. We examine the different approaches employed to reduce size and how they result in significant differences in the final device, particularly between metal- and dielectric-cavity lasers. We also present potential applications for the various forms of small lasers, and indicate where further developments are required.PostprintPeer reviewe