18 research outputs found
Tutoring instrument flight: patterns of instructor and student communication
Individual tutoring has been successful in facilitating learning in domains such as LISP, physics, and algebra. These tasks are static in that problems do not change while the student is trying to solve them. Dynamic tasks such as flying, where the problem changes spontaneously over time, represent different challenges for tutors. To understand tutoring in dynamic tasks, we conducted a field observation of students being given messages by a flight instructor. Five low flight time student pilots were asked to perform nine instrument flight tasks while being tutored by an instructor pilot in both a virtual simulator flight and in a real airplane flight. The data from our study were compared to two prominent models of one-on-one tutoring. Only a small portion of the utterances made by the tutor or by the student matched previous accounts, suggesting that a new approach is needed to address tutoring during instrument flight instruction
Design of sway frames
The aim of the work presented in this thesis is to produce a direct method to design structures subject to deflection constraints at the working loads. The work carried out can be divided into four main parts. In the first part, a direct design procedure for plane steel frames subjected to sway limitations is proposed. The stiffness equations are modified so that the sway in each storey is equal to some specified values. The modified equations are then solved by iteration to calculate the cross-sectional properties of the columns as well as the other joint displacements. The beam sections are selected initially and then altered in an effort to reduce the total material cost of the frame. A linear extrapolation technique is used to reduce this cost. In this design, stability functions are used so that the effect of axial loads in the members are taken into consideration. The final reduced cost design is checked for strength requirements and the members are altered accordingly. In the second part, the design method is applied to the design of reinforced concrete frames in which the sway in the columns play an active part in the design criteria. The second moment of area of each column is obtained by solving the modified stiffness equations and then used to calculate the mlnlmum column depth required. Again the frame has to be checked for all the ultimate limit state load cases. In the third part, the method is generalised to design pin-jointed space frames for deflection limitatlions. In these the member areas are calculated so that the deflection at a specified joint is equal to its specified value. In the final part, the Lagrange multiplier technique is employed to obtain an optimum design for plane rigidly jointed steel frames. The iteration technique is used here to solve the modified stiffness equations as well as derivative equations obtained in accordance to the requirements of the optimisation method
Jaw reflexes in subjects with temporomandibular disorders and bruxism
The overall aim of this study, was to investigate the jaw-opening reflexes in TMD patients and bruxists in order to get a better understanding of these disorders.At the beginning, it was decided to study the reflexes evoked in the masseter muscle by electrical stimulation across the lip in healthy subjects. The aim was to find the threshold at which each of the significant responses occurred and to investigate the effect of reversing the polarity of the stimulus electrode on the pattern of reflexes. A sequence of inhibitor, excitatory, inhibitory and excitatory responses could be produced in the muscle by both polarities of stimuli. It was found that stimulation of nerves supplying the skin outside the mouth evokes predominantly long-latency jaw reflexes whereas short-latency responses can be evoked by stimulating nerves supplying oral mucosa. Furthermore, long-latency excitatory reflexes seem to be the most easily evoked by stimulation of the lip.Another aim of the study was to investigate whether difference could be observed between bruxists and non-bruxists in response to electrical stimulation of the lip. In both groups, there were significant differences in the thresholds of the different responses. Also, there were differences between the two groups in the presence of the short-latency excitation and the long-latency inhibitory responses. These findings suggest that long-latency inhibitory responses evoked by electrical stimulation of the lip are weaker in bruxists than in non-bruxists.Finally, jaw reflexes in TMD patients were investigated to determine whether differences could be detected in electrically-evoked inhibitory and excitatory responses. Moreover, the occlusal splint is one of the most universally accepted forms of therapy in TMD patients and it was possible that these splints might have an effect on the pattern of jaw reflexes in view of their therapeutic effect
Determination of Naproxine in its pure form and in some Pharmaceuticals by vis-Spectrophotometry using the Chrome Azrol S
This study shows the possibility of determining the (NAP) in its pure state and in Pharmaceuticals using Chrome Azrol S Reagent . This spectral method was based on the formation of a colored violet complex at pH=3.5 , The complex has a maximum absorbance value at a wavelength of 545nm. The relationship between absorbance and naproxine concentrations was linear. The Beer-Lambert’s law is within the range of concentrations between (2.306-46.047) µg/ml and with a Relative percentage standard deviation of 1.288 and with a correlation coefficient of R2=0.9987 and a molar absorption coefficient of (1.15×104( L.mol-1.cm-1.The detection limit of naproxen was 0.5873, and the results indicated that the presence of adjuvants does not affect the determination process of naproxen.
The analytical results were characterized by a good selectivity, accuracy and sensitivity to the identification of some active substances in its pure state and pharmaceuticals, at a lower cost than the approved constitutional methods
تقدير متبقيات مبيد الدايمثوات في المياه ضمن البيئة المحيطة ببحيرة السن
إن الاستخدام غير الرشيد للكيميائيات الزراعية في بيئة حوض بحيرة السن، والأنشطة البشرية المتنوعة قد يعرض المياه للتلوث، ولاسيما بالمبيدات الفوسفورية العضوية الواسعة الاستخدام، التي لها تأثير على الجهاز العصبي.
سعى البحث إلى تحديد تركيز مبيد الدايمثوات الفوسفوري العضوي الصنعي في مياه البيئة المحيطة ببحيرة السن. تم توزيع استمارة استبيان على سكان المنطقة، للوقوف على حالة المنطقة المدروسة.
أخذت عينات مياه جوفية وسطحية من عدة مواقع تحيط ببحيرة السن. استمرت الدراسة مدة سبعة أشهر متتالية، حيث تم قياس البارامترات المختلفة (pH-EC-TDS-COD -PO4-3)، وأجري تحليل المبيد باستخدام تقانة الكروماتوغرافيا السائلة عالة الأداء HPLC. أظهرت النتائج وجود متبقيات الدايمثوات في عينات المياه المدروسة بمتوسط تراكيز تراوحت بين 1-µg.l (0.2-0.6)، متجاوزة الحدود المسموح بها وفق معايير الاتحاد الأوربي 1-µg.l (0.1)، وبالتالي لوحظ تلوث المياه الجوفية والسطحية بالدايمثوات في المواقع المدروسة، وذلك نتيجة الاستخدام المكثف له، وبسبب ذوبانيته العالية في المياه. كانت أعلى التراكيز للمبيد في الموقع غرب البحيرة، كما لوحظ ارتفاع تركيزه مع انخفاض الأس الهيدروجيني.
The study of jaw reflexes evoked by electrical stimulation of the lip:the importance of stimulus intensity and polarity
Possible gender-related differences in a jaw reflex evoked by stimulation of the human lip
The effect of occlusal splints on jaw reflexes evoked by electrical stimulation of the lower lip.
Parkinson disease: Protective role and function of neuropeptides
International audienceNeuropeptides are bioactive molecules, made up of small chains of amino acids, with many neuromodulatory properties. Several lines of evidence suggest that neuropeptides, mainly expressed in the central nervous system (CNS), play an important role in the onset of Parkinson's Disease (PD) pathology. The wide spread disruption of neuropeptides has been excessively demonstrated to be related to the pathophysiological symptoms in PD where impairment in motor function per example was correlated with neuropeptides dysregulation in the substantia niagra (SN). Moreover, the levels of different neuropeptides have been found modified in the cerebrospinal fluid and blood of PD patients, indicating their potential role in the manifestation of PD symptoms and dysfunctions. In this review, we outlined the neuroprotective effects of neuropeptides on dopaminergic neuronal loss, oxidative stress and neuroinflammation in several models and tissues of PD. Our main focus was to elaborate the role of orexin, pituitary adenylate cyclase activating polypeptide (PACAP), vasoactive intestinal peptide (VIP), opioids, angiotensin, carnosine and many others in the protection and/or involvement in the neurodegeneration of striatal dopaminergic cells. Further studies are required to better assess the mode of action and cellular mechanisms of neuropeptides in order to shift the focus from the in vitro and in vivo testing to applicable clinical testing. This review, allows a support for future use of neuropeptides as therapeutic solution for PA pathophysiology
Learn to Fly: Instructor and Student Communications in Instrument Flight Instruction
It is proposed that one-on-one human tutoring is the best way to learn. Several models of tutoring have been developed to tutor students in subjects such as LISP, Literacy, and Algebra. In this study we investigate how a keytutoring model generalizes to tutoring 5 student pilots performing instrument flight in a simulator and in an airplane