Selection of materials for marine instruments

The paper describes the selection of materials for the reliable operation of oceanographic instruments. For selecting the material, raft immersion tests were carried out for one year. Results of the tests are presented. Comparisons between metals were discussed.

The survey of sexual maturity in Mugil cephalus so measuring sex hormones and histologic studies

In this study the process of female gray mullet brooders was carried out by using histological study and masurment of sex steroids. Results of histological studies showed that oocyte of gray mullet brooders in Gomishan Rearing Center conditions of develop to the end of yolk globule stage. The results were observed with oocyte in chromatin nucleolar stage (first stage) with means of diameter of 20 p m, in August, perinucleolar stage (second stage) in September with mean diameter of 87 p m, yolk vesicle stage (third stage) in October with mean diameter 200 p m and yolk granules stage (forth stage) from October to November with average diameter of 180 — 650 p m. For the reason of stopping oocyte develop at the end of fourth stage, hormonal induction to final oocyte maturation and ovulation was used. For this purpose, carp pituitary , HCG and LRH-A2 with different combinations were used in two stages, second injection was used 24 hours after first injection. 15 females brooders were divided in 5 groups, different hormonal combinations were injected to four groups and to fifth group as control, only saline, was injected. The process of female brooder rippening in hormonal induction was studied via masurment of sex steroids including 17 a - hydroxy progestrone, estradio1-17)6 and testosterone. Blood samples were collected from caudal vein during first injection, 24, 30 and 48 hours after the first injection. At the same time, for distinguishing histological changes the sample has been attained from the gonads Sex stroid fluctuation patterns in different brooder groups that injected hormon were similar, however hormonal composition had similar effects. All brooder that their oocyte in the beginning of hormonal injection were At the end of fourth stage with oocyte diameter average of 600 p m received to final maturation and ovulation. The brooder that its oocytes were At the begining or mid-fourth stage did not show ovulation but hormonal induction caused oocyte develop at the beginning of fifth stage. Study of 17-hydroxy progestrone fluctuation showed that the maximum level of this steroid (0.347 ng/ml) measured 30 hours after the first injection and was significantly higher (p< 0.05) than those of control group. So, 17-hydroxy progestrone is probably precursor of maturation inducing steroid (MIS). However the maximum level of that observed was coincident with germinal vesicle breakdown, oil droplets coalescence and dissolution of yolk granuls The maximum levels of esteradiol— 17/0 and testosterone (3.778 and 16.801ng/ml,respectively) in spawned brooders,were observed 24 hours after the first injection. levels of those steroids were significantly higher (p<0.05) than control group. Maximum level of sex steroids in the brooders that did not spawn to the end of treatment was observed with more delay than those in spawned brooders. Therefor maximum level of 17a-hydroxy progestrone (0.264 ng/ml) in those brooders observed in fourth sampling time and the maximum levels of estradio1-17a and testosterone (2.944 and 18.993 ng/ml, respectivly)observed in third sampling time that was significantly higher (p<0.05) than those of control group. For the study of stress effect on brooders during the hormonal induction, level of cortisol was measured in every sampling time. level of cortisol had high fluctuation that showed handling level and stress effect on brooders. However maximum level of cortisol in majority of brooders was dominant in third sampling time that was coincident with final maturation.

Liver cytochrome oxidase P4501A1 purification of Acipenser persicus and designing ELISA for measuring

Moon oxygenases related to cytochrome P450s are the molecular Biomarkers which have important role in Biotransformation of endogenous and exogenous compounds and catalazyin of many biological reactions. One of the important isoenzyme is cytochrome P4501A. This isoenzyme involved in metabolism of environment pollutnts such as PAHs. Because of its inducibility, it has a key tool for impact assesment of contaminants in aquatic environment. In this study, at first, that fractions containing Acipenser persicus and Huso huso isoenzyme were purified, and after that Antibodies against them were prepared. For isolation of isoenzyme fraction, Microsomes were prepared from fish liver using differential centrifugation at high speeds. microsomes were solubiized by cholat sodium and Emulgen. Extraction of this isoenzyme was done with the combinatuion of ionexchange chromatography and gelfiltration or chromatofocusing chromatography. Ion exchange chromatography and gel filtration were applied in DEAE sepharose fast flow and sephacryl S200 respectively and chromatofocusing was done at poly buffer 74 and 94 exchanger. The results of SDS-PAGE Showed that the molecular weight of isoenzyme was about 58±1 KDa. Furthermore the inmunoblotting results confirmed this subject. Isoenzyme activigy based on EROD (Ethoxyresorofin o-deethylase) reaction showed about 20-26 fold increase in enzyme activity of treated fish than control fish. The results of Elisa, Using monoclonal anti cod P4501A demonstrated the inducibility and highly elevated of its activity in treated sample more than the control fish. Mean while, the fish sample were showed the strong reaction to polyclonal antibody against beluga P4501A1 prepared in our Lab compared to monoclonal anti body.

Measuring stiffness during arm movements in various dynamic environments

The technique presented in this paper enables a simple, accurate and unbiased measurement of hand stiffness during human arm movements. Using a computer-controlled mechanical interface, the hand is shifted relative to a prediction of the undisturbed trajectory. Stiffness is then computed as the restoring force divided by the position amplitude of the perturbation. A precise prediction algorithm insures the measurement quality. We used this technique to measure stiffness in free movements and after adaptation to a linear velocity dependent force field. The subjects compensated for the external force by co-contracting muscles selectively. The stiffness geometry changed with learning and stiffness tended to increase in the direction of the external force.

External corporate venture capital investment: Towards a framework for capturing and measuring strategic value

This paper presents the initial results of on-going research in the field of external Corporate Venture Capital (CVC) investments, i.e. equity investments of large corporations in entrepreneurial ventures which originated outside the corporation. The research is motivated by the fact that external CVC plays an increasingly important role within the strategy of corporations. Driven by a general trend towards a more open approach to innovation, companies see particular value in external corporate venturing as a tool to gain, for example, access to complementary technologies and a general window on technology developments. The review of literature in the field of external corporate venturing clearly reveals that theoretical gaps exist in understanding mechanisms for capturing value and measurements of this value. To help close these gaps, the research addresses the underlying question "How do corporations and start-ups capture and measure strategic value through external CVC investments" by using embedded, multiple case studies. Following an initial set of case studies, steps towards the development of a framework for capturing and measuring strategic value from CVC investments are outlined within this paper and the resulting preliminary framework is presented. The paper closes with an outlook on ongoing and future research steps. © 2009 PICMET.

Measuring the kinetics of amyloid fibril elongation using quartz crystal microbalances.

Kinetic measurements of amyloid growth provide insight into the free energy landscape of this supramolecular process and are crucial in the search for potent inhibitors of the main disorders with which it is associated, including Alzheimer's and Parkinson's diseases and Type II diabetes. In recent years, a new class of surface-bound biosensor assays, e.g., those based on surface plasmon resonance (SPR) and the quartz crystal microbalance (QCM) have been established as extremely valuable tools for kinetic measurements of amyloid formation. Here we describe detailed protocols of how QCM techniques can be used to monitor the elongation of amyloid fibrils in real time and to study the influence of external factors on the kinetics of amyloid growth with unprecedented accuracy.

Measuring shaft friction during earthquakes

The failure of piled foundations has been observed in many earthquake events. The manner in which a pile is able to support its applied superstructure loading during an earthquake is not yet fully understood, particularly with respect to the shaft friction capacity. In this paper, new pile group is presented which has been instrumented to measure the shaft friction distribution along the length of a pile. In addition, this pile group is able to measure the pore pressures directly beneath the pile tips. The pile group was tested in dynamic centrifuge experiments and showed differing shaft friction behaviour in dense and loose soil layers as well as strong dilation beneath the pile tips at the start of earthquake loading. A reduction in shaft friction was observed after the earthquake due to soil down-drag. © 2010 Taylor & Francis Group, London.

I did that! Measuring users' experience of agency in their own actions

Cognitive neuroscience defines the sense of agency as the experience of controlling one's own actions and, through this control, affecting the external world. We believe that the sense of personal agency is a key factor in how people experience interactions with technology. This paper draws on theoretical perspectives in cognitive neuroscience and describes two implicit methods through which personal agency can be empirically investigated. We report two experiments applying these methods to HCI problems. One shows that a new input modality - skin-based interaction - can substantially increase users' sense of agency. The second demonstrates that variations in the parameters of assistance techniques such as predictive mouse acceleration can have a significant impact on users' sense of agency. The methods presented provide designers with new ways of evaluating and refining empowering interaction techniques and interfaces, in which users experience an instinctive sense of control and ownership over their actions. Copyright 2012 ACM.

Integrated high pressure microhydraulic actuation and control for surgical instruments

To reduce the surgical trauma to the patient, minimally invasive surgery is gaining considerable importance since the eighties. More recently, robot assisted minimally invasive surgery was introduced to enhance the surgeon's performance in these procedures. This resulted in an intensive research on the design, fabrication and control of surgical robots over the last decades. A new development in the field of surgical tool manipulators is presented in this article: a flexible manipulator with distributed degrees of freedom powered by microhydraulic actuators. The tool consists of successive flexible segments, each with two bending degrees of freedom. To actuate these compliant segments, dedicated fluidic actuators are incorporated, together with compact hydraulic valves which control the actuator motion. Especially the development of microvalves for this application was challenging, and are the main focus of this paper. The valves distribute the hydraulic power from one common high pressure supply to a series of artificial muscle actuators. Tests show that the angular stroke of the each segment of this medical instrument is 90°. © 2012 Springer Science+Business Media, LLC.