bluuebunny/crossref_metadata_2025 huggingface dataset:
Groundwater in fractured granite for water supply to remote areas in Malaysia
Authors: Sapari N. , Azie R.J. Raja , Jusoh H.
Published: June 2010

Groundwater in fractured granite in Malaysia was found to be an economical source of water supply for various remote industries and communities. The uses include for agricultural processing, mineral water bottling, granite quarry, golf course irrigation and drinking water supply. Forty five tubewells belong to private companies operating in various places in the area were evaluated in terms of the yields and water quality. The wells were drilled using rotary air-percussion method to a maximum depth of 200 m and provided with 6 inch PVC casing and screens.

The productivity of the wells and the characteristics of aquifer were evaluated by pumping tests using a constant discharge rate and step drawdown methods. The average yield of the wells at allowable drawdown of 40 m was found to be 428 m3 per day. Results from water quality analysis indicate that the water is fresh with total dissolved solids (TDS) concentration between 101 and 150 mg/L. The hardness of the water varies from as low as 9.01 mg/L to a maximum of 337 mg /L. On the average the water is moderately hard with the hardness value of 73.17 mg/L. The water facies of the groundwater was found to be of Calcium-Sodium-Bicarbonate water.
Over-Nutrition and Changing Health Status in High Income Countries
Authors: Huffman Wallace E. , Huffman Sonya K , Rickertsen Kyrre , Tegene Abebayehu
Published: June 2010

As per capita incomes in developed countries have grown over the past three decades, over-nutrition leading to obesity and elevated health risks for cardiovascular disease, diabetes and some forms of cancer has occurred. We use economic and econometric models to identify the impact of food prices on the aggregate demand for calories and the supply of health, as reflected in mortality rates. Our models are fitted to unique panel data for 18 developed countries over 1971-2001, a period when the relative price of food first rose and then declined steadily. Some findings, using de-trended data, are that a lower real price of food, of other purchased consumer goods and of time increase the demand for calories, one cause of energy imbalance, and the supply of mortality associated with obesity. These prices do not affect the rate of non-obesity-related mortality. Caloric intake is a normal good, contributing to energy imbalance as income increases, but higher incomes do reduce mortality risk. However, higher labor force participation rates, largely associated with rising numbers of working women, and a higher child dependency ratio lead to a higher rate of obesity-related mortality. An implication of our results is that further reductions in the price of food in developed countries can be expected to have a net negative impact on health as reflected in a higher mortality rate due to diseases that are linked to obesitydiabetes, cardiovascular diseases and most forms of cancer.
Sign of the Buttock Following Total Hip Arthroplasty
Authors: Burns Scott A. , Burshteyn Mark , Mintken Paul E.
Published: June 2010

The patient was a 68-year-old man who had undergone a right total hip arthroplasty 3 years prior. He complained of progressively worsening right hip pain. Physical examination findings were consistent with a positive sign of the buttock. A triple-bone scan showed increased radio-pharmaceutical activity, which is consistent with infection. Subsequent aspiration of the right hip revealed infection, which was treated with antibiotics before the patient underwent a revision total hip arthroplasty.

J Orthop Sports Phys Ther 2010;40(6):377. doi:10.2519/jospt.2010.0410
Recipient targeting for revascularization using pulsed Doppler ultrasonography for the treatment of an intracranial giant aneurysm
Authors: Tani Shoichi , Akiyama Yoshinori , Tokime Tomoo , Taki Junya , Ogino Eiji , Nishida Sei
Published: June 2010

Aneurysmal occlusion after blood flow revascularization is a promising management strategy for the treatment of intracranial giant aneurysms. However, it is necessary to design robust revascularization for preventing postoperative flow-related infarctions caused by abrupt occlusion of the parent vessels. Since direct anastomosis of donor vessels to recipient vessels near giant aneurysms is often difficult, it is preferable to select cortical recipient branches away from the aneurysm, thus providing a sufficient working space for the surgeon. In this paper, the authors' goal was to identify distal cortical recipient arteries on the brain surface, based on pulsed Doppler ultrasonography analysis of blood flow alteration after temporary closure of the efferent vessels. This method is used to visualize the area around the sacrificed vessels, omits intraoperative arteriography or the risk of a surgical trace of the vessels by dissecting the distal sulci, and could be advantageous for necessary and sufficient revascularization.
Postoperative seizures following the resection of convexity meningiomas: are prophylactic anticonvulsants indicated?
Authors: Sughrue Michael E. , Rutkowski Martin J. , Chang Edward F. , Shangari Gopal , Kane Ari J. , McDermott Michael W. , Berger Mitchel S. , Parsa Andrew T.
Published: June 2010

Object

Seizures in the perioperative period are a well-recognized clinical entity in the setting of brain tumor surgery. At present, the suitability of antiepileptic prophylaxis in patients following brain tumor surgery is unclear, especially in those without prior seizures. Given the paucity of tumor-type and site-specific data, the authors evaluated the incidence of postoperative seizures in patients with convexity meningiomas and no prior seizures.

Methods

The authors identified 180 patients with no preoperative history of seizures who underwent resection of a convexity meningioma. Some patients received antiepileptic prophylaxis for 7 days postoperatively while others did not, based on the practice patterns of different attendings. The rates of clinically evident seizures in the first 3–4 weeks after surgery were compared.

Results

Patients who received antiepilepsy drugs (129 patients) did not significantly differ from those who did not (51 patients) in terms of age, sex, WHO tumor grade, extent of resection, rate of previous cranial surgery or radiation therapies, or use of preoperative embolization. There was a single new postoperative seizure in the entire cohort, yielding a new seizure rate of 1.9% in patients not on antiepileptic prophylaxis compared with 0% in patients on antiepileptics (p = not significant).

Conclusions

While it is thought that the routine use of prophylactic antiepileptics may prevent new seizures in patients undergoing surgery for a convexity meningioma, the rate of new seizures in untreated patients is probably very low. Data in this study call into question whether the cost and side effects of these medications are worth the small benefit their administration may confer.
Saccular aneurysm with basal rupture angiographically depicted as an aneurysm with stalk-like narrow neck
Authors: Park Jaechan
Published: June 2010

On occasion, the wall of the aneurysm base can be the rupture site of the lesion, which poses a unique challenge for treatment. Although there has already been a report of the angiographic depiction of a basal rupture of a saccular aneurysm by a small outpouching at the aneurysm neck, this is the first report of saccular aneurysms in which a basal rupture was angiographically depicted as a stalk-like narrow neck due to a thrombus sealing the rupture point and occupying the lumen of the aneurysm base. The author reports on 2 such cases: a 49-year-old woman who presented with a basal rupture of a saccular aneurysm arising at the middle cerebral artery bifurcation, and a 44-year-old man who presented with rupture of a saccular aneurysm arising at the junction of the A2 segment and the anterior communicating artery. In both cases, a pterional craniotomy allowed the surgeon to determine that the base of the aneurysm was ruptured, and he surgically obliterated the aneurysm. Microsuture reconstruction and clipping of the aneurysm neck were successful in obliterating the ruptured aneurysm and avoiding any compromise of the parent artery.
In vitro Release Kinetic Study of Theophylline from Eudragit RS PO and Eudragit RL PO Matrix Tablets
Authors: Apu Apurba Sarker , Pathan Atiqul Haque , Kibria Golam , Jalil Reza-ul
Published: June 2010

The aim of the present study was to investigate the release kinetics of theophylline from permeableacrylic polymer matrix tablets. Matrix tablets were prepared by direct compression method using Eudragit RS PO andEudragit RL PO. Two batches of matrix tablets were prepared. Only Eudragit RS PO was used in the first batch, andin the second batch both Eudragit RS PO and Eudragit RL PO were used as the rate retarding polymers in differentproportions. The variation of hardness was insignificant in batches. Drug release was investigated by using USPbasket method and the results of release rates were analyzed by using correlation coefficient value of Zero orderrelease plot & Higuchi plot and exponent value of Bi-exponential release profile. Theophylline tablets having onlyEudragit RS PO showed comparatively slow release but release rate improved significantly as seen in formulationscontaining Eudragit RL PO and Eudragit RS PO. It was also revealed that, in all cases the release of theophyllinefollowed mixed release kinetics where Zero order release kinetics was predominant.Key words: Sustained release; matrix tablet; theophylline; acrylic polymers; eudragit; release rate; dissolution;hardness.DOI: 10.3329/dujps.v8i1.5328Dhaka Univ. J. Pharm. Sci. 8(1): 1-6, 2009 (June)
Phytochemical and Biological investigations of Phoenix paludosa Roxb.
Authors: Alam Farzana , Rahman Mohammad S , Alam Md Shahanur , Hossain Md Khalid , Hossain Md Aslam , Rashid Mohammad A
Published: June 2010

Lupeol (1), epilupeol (2) and β-sitosterol (3) were isolated from the n-hexane and the carbontetrachloride soluble fraction of a methanol extract of the leaves of Phoenix paludosa Roxb. The n-hexane, carbontetrachloride and chloroform soluble materials from the concentrated methanol extract were subjected toantimicrobial screening and brine shrimp lethality bioassay. All of the partitionates showed insensitivity to microbialgrowth, while the n-hexane, chloroform and methanol soluble fractions showed significant cytotoxicity having LC502.17 μg/ml, 2.77 μg/ml and 2.46 μg/ml, respectively. This is the first report of isolation of the compounds 1-3 andbioactivities of P. paludosa.Key words: Phoenix paludosa; Aracaceae; Lupeol; Epi-Lupeol; β-sitosterol; Brine shrimp lethality bioassay;Antimicrobial.DOI: 10.3329/dujps.v8i1.5329Dhaka Univ. J. Pharm. Sci. 8(1): 7-10, 2009 (June)
Leaf Extracts of Azadirachta indica and Terminalia arjuna Induce Death of HeLa cells without DNA Degradation
Authors: Chowdhury Miraj Kobad , Ahsan Nazmul , Akhand Anwarul Azim
Published: June 2010

Cancer is one of the major causes of death all over the world. Different attempts have been taken forthe prevention and cure of this devastating disease. Along with various chemically synthesized drugs, extracts fromdifferent medicinal plants have been studied to combat cancer. In this study, the effects of leaf extracts fromAzadirachta indica and Terminalia arjuna have been investigated on HeLa cells, a well known human cancer cellline. Both of the extracts were found to cause death of HeLa cells dose-dependently. However, the extract of T.arjuna was found more promising than the extract of A. indica in mediating cell death. At a concentration of 50μg/ml, T. arjuna extract killed 95% cells, whereas the same concentration of A. indica extract killed only 55% cells.In many cases, cell death induced by various chemicals often involves fragmentation of DNA. In this study, theextracts of both plants did not induce any detectable level of HeLa cell DNA fragmentation as demonstrated byagarose gel electrophoresis. This result argued that the cell death might occur before initiation of the process ofcellular DNA fragmentation bypassing the apoptotic pathway of cell death.Key words: Cancer; Cell death; Azadirachta indica; Terminalia arjuna.DOI: 10.3329/dujps.v8i1.5339Dhaka Univ. J. Pharm. Sci. 8(1): 75-79, 2009 (June)
Ecology as Text, Text as Ecology
Authors: Morton Timothy
Published: June 2010

The further scholarship investigates life forms (ecology, evolutionary biology and microbiology) the less those forms can be said to have a single, independent and lasting identity. The further scholarship delves into texts (deconstruction) the less they too can be said to have a single, independent and lasting identity. This similarity is not simply an analogy. Life forms cannot be said to differ in a rigorous way from texts. On many levels and for many reasons, deconstruction and ecology should talk to one another. It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. (Charles Darwin, The Origin of Species, 395–396)
Waste and Welter: Derrida's Environment
Authors: Sellars Roy
Published: June 2010

At first sight, environmental issues do not seem to feature prominently, if at all, in the work of Jacques Derrida. This essay aims to take a closer look, and thereby to issue a challenge to the burgeoning discipline of eco-criticism. Instead of promoting the Beautiful Soul who is equipped to save the planet by virtue of reading poetry, I argue for the ethical primacy of waste and welter (to recycle a phrase from Wallace Stevens). Jonathan Bate's The Song of the Earth, a powerful but pious work of eco-criticism, ends with a test proposed to the reader; I take the test, which entails reading Stevens's late poem ‘The Planet on the Table’, and fail. Bate's invocation of Martin Heidegger is briefly examined, as are traces of Derrida. What remains of Derrida, I propose, is neither method nor concept but rather remainders that trouble the grounding of environment (Umwelt) as such.
The Thing Called Environment: What It Is and How to Be Concerned With It
Authors: Goeminne Gert , François Karen
Published: June 2010

This paper wants to think beyond the science-politics divide that is omnipresent in sustainability discourse. With Bruno Latour, we investigate if and how decomposing matters of fact and recomposing them back as matters of concern can open up a scientific-political space in which sustainability challenges can be addressed in an adequate manner. By connecting Latour's constructivist account of science in action with Rudolf Boehm's concept of topical truth, we aim to lighten up the normative-political entanglement between science and politics, facts and values. Rather than conceiving of knowledge in terms of representations of the world, a constructivist topical perspective emphasises the socio-material practices from and within which these representations arise. Such a view then also changes the way we think about ourselves and our place in the world in fundamental ways: the world now becomes something that we are embedded in and part of rather than something we are detached from and merely observers of, as representationalism suggests. In this way, decomposing environmental matters of fact such as climate change, which have never been a human-independent entity out there to begin with, allows to adequately recompose them as societal matters of concern, which they have been from the very beginning.
Some Climate Change Ironies: Deconstruction, Environmental Politics and the Closure of Ecocriticism
Authors: Clark Timothy
Published: June 2010

This paper considers the deconstructive force of climate change in intellectual and political life, especially as it undermines and challenges the terms of consumer democracy and the liberal tradition in political thought. The first half of the paper gauges this deconstructive force in relation to Derrida's legacy, arguing that environmental questions open an arena of deconstructive events foreclosed in Derrida's own work. The second half considers the deconstructive force of climate change in relation to literary ecocriticism, the study of literature and the environment.
Hydrothermal Synthesis of Metal Oxide Nanoparticles in Supercritical Water
Authors: Hayashi Hiromichi , Hakuta Yukiya
Published: June 2010

This paper summarizes specific features of supercritical hydrothermal synthesis of metal oxide particles. Supercritical water allows control of the crystal phase, morphology, and particle size since the solvent's properties, such as density of water, can be varied with temperature and pressure, both of which can affect the supersaturation and nucleation. In this review, we describe the advantages of fine particle formation using supercritical water and describe which future tasks need to be solved.
Resistance to Integrase Inhibitors
Authors: Métifiot Mathieu , Marchand Christophe , Maddali Kasthuraiah , Pommier Yves
Published: June 2010

Integrase (IN) is a clinically validated target for the treatment of human immunodeficiency virus infections and raltegravir exhibits remarkable clinical activity. The next most advanced IN inhibitor is elvitegravir. However, mutant viruses lead to treatment failure and mutations within the IN coding sequence appear to confer cross-resistance. The characterization of those mutations is critical for the development of second generation IN inhibitors to overcome resistance. This review focuses on IN resistance based on structural and biochemical data, and on the role of the IN flexible loop i.e., between residues G140-G149 in drug action and resistance.
Afghánistán mezi optimismem a defétismem
Authors: Zipfel Tomáš
Published: June 2010

The article deals with the situation in Afghanistan and the possibilities of particular parties in the crisis. The initial part presents the current status which is characterized by increasing activities of opposition militia forces and by growing civilian and coalition casualties. The second part introduces possible strategies with respect to the different character of various opposition groups, represented by conservative-nationalistic formations that are a subject for possible negotiation as well as jihadist groups that have to be eliminated. The following section focuses at expected stance of ongoing US administration towards possible arrangement and potential US strategies of exit. The last passage of the article addresses the necessary measures for any successful solution of the Afghan issue.
EUJUST LEX The EU integrated rule of law mission for Iraq
Authors: White Stephen
Published: June 2010

In his article Mr White provides (as a head of the mission) an insight into the success story of the ESDP Integrated Rule of Law Mission for Iraq, "EUJUST LEX". He sets the complex political and security context in which his Mission operates and describes the challenges the Mission has been facing since its inception in July 2005. He outlines the principles and objectives he has set for himself and his team as well as some of the Critical Success Factors (CSF) which have contributed to the Mission's achievements.
Problematika a principy uplatnění targeted assassinations v boji proti terorismu
Authors: Janků Martin
Published: June 2010

The article deals with the issue of targeted killings (assassinations) and its exploitation in the "war on terror" and counter-terrorism policy in general. For the purpose of the analysis, targeted killings are viewed in three dimensions and consequences - legal, moral (ethical) and efficiency. Although this tactic and its usage are very controversial, particular analysis from the perspective of these three dimensions might be helpful not only to consider targeted killing as a legitimate instrument to fight terrorism, but simultaneously all specific conditions resulting from these dimensions (most prominently the legal one) have to be satisfied.
Sekuritizace hrozby nedostatku vody v České republice
Authors: Martinovský Petr
Published: June 2010

In recent years, a threat of water scarcity has been a frequently discussed topic in security and strategic studies. However, we lack evaluative researches on this threat in the Central European area, especially in the Czech Republic. The aim of this paper is to help with filling the vacancy and to explore the reflection of the threat of water scarcity among Czech security policy actors. Appropriate methodological ground is provided by the constructivist concept of securitization by the Copenhagen School of Security Studies. Primary data have been obtained from questionnaires, secondary and tertiary data subsequently from relevant actors' documents analysis. In the final part of the study, the author partially steps aside from the constructivist view and on the basis of observed trends summarizes the main objective features of the threat itself.
Vojenská reforma v kontexte bezpečnostnej politiky Ruskej federácie
Authors: Horemuž Martin
Published: June 2010

The article analyzes the Russian military reform in context of security policy of the Russian Federation after the Soviet Union break up in 1991. In this connection it observes main features and problems connected with the military reform. Crucial for this period were wide changes in the international security environment (break up of bipolar system of international relations), which had a direct influence on redefinition and new formation of security politics of many countries, including Russia. On the other hand, this period meant specific conditions for the Russian Federation, during which the country was internally confronted with economy transformation effected during the whole period of the 90's by permanent economical and social crises, creating of a new political system and searching of its post-imperial identity in the system of international relations.
Operace Lité olovo z pohledu izraelských strategií odstrašování
Authors: Kalous Miroslav
Published: June 2010

The study is concerned with the Israeli invasion to Gaza (named by Israelis operation Cast Lead) which was launched in December 2008 and provoked a lot of controversy. One particular stream of public discussion which perked up at the time of pulling back Israeli forces has been dealing with the question if the operation was successful in terms of improving Israeli deterrent potential. The study also asks this question but in a more profound and structured manner. In order to do so it sees the operation and a few preceding and following months through the lens of four different conceptions of deterrence which can be found in Israeli security thinking (and were laid out by Uri Bar-Joseph in 1998). More specifically, the study tries to answer these questions: Which strategy of deterrence had Israel used before operation Cast Lead? Which strategy could have been strengthened by the operation? Did this strengthening actually occur?
Evropská obranná agentura v šesti letech
Authors: Kolín Vilém
Published: June 2010

In 2010, it will be six years since the establishment of the European Defence Agency (EDA), which seeks to improve defence capabilities of the Member States of the European Union (EU) in crisis management to sustain Common Security and Defence Policy (CSDP). The article describes the EDA Strategic Framework, consisting of four basic strategic documents that correspond with the EDA main tasks in the area of defence capabilities development, research and technology co-operation, armaments co-operation, and the creation of the European Defence Equipment Market (EDEM), while strengthening the European Defence Technological and Industrial Base (EDTIB). Against the background of the EDA Strategic Framework, the article maps the current major EDA projects and identifies the main challenges the EDA will face in the near future.
Zpravodajský cyklus klišé nebo nosný koncept?
Authors: Zeman Petr
Published: June 2010

The widely-spread concept of the intelligence cycle is usually considered banal. In fact, it comprises many theoretical and primarily practical issues. The paper newly defines the stages of the cycle, compares the Czech terminology to the foreign ones (namely the English one); aims to denominate some issues and suggests how to resolve them. A significant critical focus of the paper consists in discussing activities that rarely get proper attention: definition of the inputs or the tasking, primary processing of raw information, and finally some of the difficulties regarding distribution of finished intelligence to legitimate users. The paper considers correctness of the concept in the world/environs of defensive intelligence activity. Eventually, the paper confirms that the concept of the intelligence cycle is useful: it reflects a factual distribution of labour within the intelligence agencies and makes the internal self-reflection within them possible.
Jus in Bello and Operation Iraqi Freedom
Authors: Durpektova Eva , Kriz Zdenek
Published: June 2010

War is a constant feature of human affairs and a permanent topic of ethical debates. Moral reasoning about war and peace known as just war theory has its roots in Christian ethics and is connected to positive international law. The theory is doubly critical - it serves as a tool for evaluating the justice of a state's decision to go to war, as well as its conduct in particular warfare. The article uses the latter part of just war theory as an analytical tool for answering the question whether the allied conduct during the Operation Iraqi Freedom in 2003 met the criteria of justice in war (jus in bello). Two main principles of jus in bello are discrimination and proportionality. These moral categories aim at reducing the damage and destruction incurred in war. The Operation Iraqi Freedom was conducted with awareness of the importance of these principles, because the U.S. Army used new weapon technologies, mainly precision-guided missiles, that reduced the casualties among Iraqi civilians.
Nuclear deterrence and the concept of MAD in the relations between the U.S.A. and the RF
Authors: Honkova Jana , Suchy Petr
Published: June 2010

The text analyses the position, role and perception of mutual nuclear deterrence between the United States and the Russian Federation in the period after the end of the Cold War. The authors argue that the deterrence is still present in the Russian-American relationship, despite the fact, that its intensity significantly decreased. They come to conclusion that this feature of mutual relationship is going to be present in the foreseeable future as well as the ongoing debates.
Temps et causalité dans les raisonnements des étudiants en physique
Authors: Viennot Laurence
Published: June 2010

This paper deals with the way that students interpret relationships between physical quantities with respect to time, especially those involving physical quantities that are considered at the same time. Research findings show some important difficulties which are probably linked with a causal interpretation of phenomena. The main features of “linear causal reasoning” about systems, as opposed to a quasi-static analysis, are described and illustrated. The paper ends with a discussion about pedagogical goals.
Approches théorique et empirique de la causalité
Authors: Ogborn John
Published: June 2010

La causalité est discutée de deux points de vue complémentaires : théorique et empirique. Dans la discussion théorique, nous nous élevons contre la position adoptée par Hume selon laquelle il n’existerait pas de causalité, et reprenons des idées issues des travaux de Piaget et des sciences cognitives pour développer une analyse de la causalité. Ce point de vue est appuyé par des arguments de nature linguistique. Nous décrivons ensuite plusieurs études empiriques du raisonnement causal intéressant l’enseignement des sciences. L’une teste une théorie causale des idées quotidiennes de force et de mouvement ; les autres explorent l’ontologie attribuée par des sujets à des entités quotidiennes ou scientifiques. Nous proposons enfin quelques dimensions ontologiques fondamentales.
Jouer les notes sans connaître la mélodie : le caractère étroit de la recherche en didactique de la biologie
Authors: Lucas A. M.
Published: June 2010

Au cours des vingt dernières années, de nombreuses recherches ont été menées sur la façon dont les élèves et les étudiants comprennent les concepts scientifiques. Ce mouvement international a fourni un corpus très vaste de données intéressantes, mais malheureusement beaucoup d’études ont concerné des concepts isolés et étroits. Très peu s’intéressent à la façon dont les apprenants intègrent les idées dans une structure conceptuelle large. Ce manque est particulièrement important dans la recherche en didactique de la biologie ; celle-ci doit non seulement tenir compte des concepts de physique, chimie et mathématiques, mais aussi des concepts biologiques “englobants”, dont la signification se développe au sein des sciences biologiques.
Prégnance de l'explication électrostatique dans la construction du concept de circuit électrique : points de vue historique et didactique
Authors: Benseghir Abdelmadjid , Closset Jean-Louis
Published: June 2010

This study deals with the construction of the concept of an electrical circuit considered from two points of view, historical and psychogenetic. In both cases we show that the previously acquired knowledge of electrostatics is liable to be a “misleading framework” for constructing the concept of an electrical circuit. We provide evidence of a process of reinvestment of their electrostatic knowledge : students focussed their attention on charges located at the generator’s terminals, even in a closed circuit, these charges being seen as the essential elements in the analysis of the circuit.
Homomorphismes réel-représentation et signifié-signifiant : exemples en mathématiques
Authors: Vergnaud Gérard , Prévost Philippe
Published: June 2010

In this article, the author emphasizes that the concept of homomorphism is important for analyzing the relations between reality and its representation, as well as for graphic representations (concept maps and others) and other representations of scientific concepts.

The research adresses the functionnality of the spatial representations of scientific concepts. On one hand, the problem of selecting elements can be related with the thought operations necessary for reading a graphical representation. On the other hand, the relation between the organization of the graphical representation and the signifier/signified link poses a symbolization problem.
Des études didactiques pourraient-elles aider l'enseignement des savoirs professionnels ? Le cas des mathématiques dans les pratiques professionnelles
Authors: Mercier Alain
Published: June 2010

Este artículo propone un primer enfoque teórico de un problema frecuentemente planteado y resuelto en la acción : la definición de la base general de conocimientos que se deben enseñar en el marco de una formación técnica dada. Se trabaja la noción de instrumento con la la intención de mostrar cómo los conocimientos matemáticos son presentados como un artefacto para que parezcan transparentes a los que los utilizan. La noción de encuesta sobre las matemáticas instrumentales para une práctica profesional podría así ayudar a re-problematizar las relaciones entre la enseñanza de la disciplina y la formación profesional.
Le traitement statistique des mesures en travaux pratiques de physique de DEUG : une innovation à Orsay
Authors: Séré Marie-Geneviève , Journeaux Roger
Published: June 2010

Une innovation en premier cycle universitaire (première année de DEUG : Diplôme d’Études Universitaires Générales) est décrite dans cet article. Elle consiste en l’adaptation de travaux pratiques de physique pour aborder l’estimation des incertitudes par un traitement statistique des données expérimentales. Cette approche nouvelle a été précédée d’une recherche didactique qui a mis en évidence chez les étudiants des difficultés d’ordre épistémologique (déterminisme , rôle du hasard) et d’ordre conceptuel (dispersion, précision). Les séances sont conçues de telle façon que les concepts du domaine et les outils mathématiques sont progressivement introduits en fonction du problème posé, avec une interaction enseignants-étudiants importante. Par ailleurs, des questions écrites servent de guide aux étudiants et permettent une analyse de leurs réactions et productions.
Étude d'épreuves de physique-technologie au concours de recrutement du professorat des écoles en France : Que devraient savoir les candidats ?
Authors: Martinand Jean-Louis , Lebeaume Joël
Published: June 2010

En France, la formation des professeurs des écoles à renseignement des «sciences et technologie» est actuellement une question importante posée aux nouveaux Instituts Universitaires de Formation des Maîtres. À partir de l’analyse des épreuves de «physique-technologie» au concours de recrutement, l’étude présentée tente d’une part d’identifier les compétences implicitement mesurées à l’issue de la première année de formation, et d’autre part d’en faire apparaître le niveau d’exigence. Après en avoir repéré les orientations majeures, l’étude suggère des perspectives pour construire la formation.
Les analogies dans l'acquisition de concepts en biologie chez des élèves de 10-11 ans
Authors: Gineste Marie-Dominique , Gilbert Laurent
Published: June 2010

Este estudio está consagrado a la analogía como proceso pedagógico en lecciones donde el dominio no puede ser aprehendido por una observacion directa. Dos temas han sido seleccionados : los componentes de la célula y los cambios gaseosos en la sangre. La modalidad seleccionada para las analogías fue la ilustraciôn, las correspondencias entre ilustración y tema siendo o no explicitadas a los alumnos. Pareciera que las analogías ilustradas y comentadas, favorecen la adquisición de conocimientos. Se insiste sobre las exigencias cognitivas requeridas para asegurar el éxito en el uso de las analogías.
L'histoire des sciences dans la formation scientifique des maîtres de l'école élémentaire
Authors: Rosmorduc Jean
Published: June 2010

«Polivalencia» individual de cada profesor de escuela o «polivalencia» de un equipo pedagógico restringido ? El autor argumenta en favor de la segunda fórmula. En el dominio científico, una cultura común del equipo séria necesaria. El objeto de este artfculo es de mostrar que la historia de las ciencias debe ser uno de los componentes de una tal cultura.
Les habitudes des enseignants et les intentions didactiques des nouveaux programmes d'électricité en classe de quatrième
Authors: Couchouron Monique , Viennot Laurence , Courdille Jean-Marie
Published: June 2010

La mise en place de nouveaux programmes nécessite, de la part des enseignants, une prise en compte des intentions des rédacteurs puis une traduction de celles-ci en actes pédagogiques. Nous nous intéressons ici à la perception que les enseignants ont des intentions didactiques contenues dans le nouveau programme d’électricité de la classe de quatrième en France. Des entretiens semi-directifs, conduits avec neuf enseignants, semblent montrer que leur expérience professionnelle, leurs habitudes, limitent leur perception des nouveautés malgré une bonne connaissance des difficultés que les modifications de programme visent à résoudre. Les formes particulières de cet effet de filtrage sont analysées. On observe à ce propos qu’il peut être utile d’associer des intentions didactiques nouvelles à un objet matériel lui-même nouveau qui leur serve de support.
Investigations des élèves en science : une approche fondée sur la connaissance
Authors: Millar Robin
Published: June 2010

It is widely agreed that one outcome of school science should be an understanding, amongst students, of the scientific approach to enquiry. Analysis of typical science investigation tasks shows the wide range of understandings required to carry out such tasks successfully. A model linking aspects of understanding to elements of performance developed by the Procedural and Conceptual Knowledge in Science (PACKS) project is briefly described. Two parts of this model, concerned with the investigation «frame» chosen by students and their collection and use of data as evidence, are explored in the context of an investigation of thermal insulation. It is argued that school science needs to do more to move students from a perception of investigation as «personal enquiry» towards «public enquiry», where evidence for conclusions is displayed ; and that a knowledge-based model of science performance provides a better basis than skills-based models for teaching, curriculum planning and research.
Étude des critères du concept de vie chez des élèves de sixième
Authors: Rolland Annie , Marzin Patricia
Published: June 2010

El concepto de vida es raramente enseñado como tal en las clases de secundaria en Francia. Como nosotros lo mostramos en este artículo, no existe consenso en la comunidad científica actual para definir este concepto clave de la bilogía. A lo largo de la historia, y todavía hoy, dos concepciones coexisten y son el origen de diferentes teorías : el animismo y el mecanismo. En este contexto no consensual nosotros nos hemos planteado las siguientes preguntas : ¿cómo los alumnos de sexto (correspondiente al primer año de la educación secundaria en Francia) se representan al viviente ? ¿Cuáles son los criterios considerados por ellos, para determinar lo que es viviente o no ?
Enseigner et apprendre les sciences : représentations sociales de futurs enseignants et enseignantes
Authors: Ruel Françoise , Désautels Jacques , Larochelle Marie
Published: June 2010

In this research we examine the theoretical framework with which ten student teachers conceptualise what they mean by learning and teaching science. In order to do so, we make use of the concept of social representation as a conceptual instrument to explore the almost inextricably linked cognitive and social aspects of their conceptions, as well as the relations they establish between theory and pratice. Using a qualitative methodology, and in particular analysis of discourses obtained through individual interviews, this research shows the sociocultural anchoring of the views expressed by future science teachers.
Expérimentation, instrumentation et argumentation
Authors: Gingras Yves , Godin Benoît
Published: June 2010

L’objet de ce texte est de présenter un rapide survol de révolution historique du rôle de l’expérimentation et de l’instrumentation dans les sciences de la nature et de proposer un modèle de la dynamique de l’activité scientifique qui fasse ressortir le rôle de l’argumentation dans la validation des connaissances au sein d’un champ scientifique.
L'enseignement des sciences physiques dans les sections de baccalauréat professionnel : compte rendu d'innovation / Teaching physics in classes of «baccalauréat professionnel»: report of innovation
Authors: Secrétan Daniel
Published: June 2010

The teaching of physics has been thoroughly updated in classes of baccalauréat professionnel since 1996. The new syllabuses principally aimed at providing students with principles of scientific culture which is necessary for all citizens, so that they get specialized in basic scientific methods and knowledges. In order to reach these targets, syllabuses are divided into two clear-cut components : a basic methodologic training for all baccalauréats professionnels and a specialized training composed of special units which are chosen according to the different baccalauréats professionnels. It is absolutely necessary to have a concrete point of view on posed problems : consequently, students do carry out experiments in practicals and labworks. From 1998, the experimental abilities of applicants will be tested through a practical exam.
La propagation des ondes en dimension 3 : analyse des difficultés des étudiants quant au modèle géométrico-ondulatoire / Analysis of students' difficulties on the wave geometrical model of three dimensional waves
Authors: Maurines Laurence
Published: June 2010

Cet article analyse la manière dont les étudiants utilisent les concepts de «rayon» et de «surface d’onde» ainsi que le principe de Huygens-Fresnel pour décrire, expliquer et représenter graphiquement des situations où une onde (sonore ou lumineuse) se propage selon plusieurs directions (propagation, réflexion, diffraction). Pour les deux types d’onde, on note les mêmes tendances vers un raisonnement de type géométrique et mécaniste, vers une réduction du nombre de variables, vers une matérialisation des concepts. Quelques remarques sur des livres scolaires ou de vulgarisation et quelques propositions pédagogiques sont faites.
Recherches didactiques sur la formation professionnelle des enseignants de mathématiques du second degré et leurs pratiques en classe / Didactical research work on practices of mathematical teachers in the classroom and on their training
Authors: Robert Aline
Published: June 2010

Didactical research work on practices of mathematical teachers in the classroom and on their training

In this article, we investigate the issue of research works on training of mathematical teachers (at the secondary level). We choose a theoretical level to submit our reflection and this leads us to suggest that our knowledge on teachers’ practices in the classroome is not yet sufficient. We propose then our problematics and some methodological directions to analyse those practices. We illustrate our proposals by relating an exemple of such effective work research.
Les difficultés d'étudiants post-bac pour une conceptualisation cohérente de la diffraction et de l'image optique / Coherent conceptualization of diffraction and optical imaging : university students' difficulties
Authors: Colin Philippe , Viennot Laurence
Published: June 2010

Cet article vise à mettre en évidence les difficultés d’étudiants (deuxième et troisième années universitaires) à propos de situations d’optique qui s’analysent classiquement, dans l’enseignement, à l’aide de deux «modèles» à la fois : «géométrique» et «ondulatoire». Les résultats de trois questionnaires confirment l’existence de problèmes importants pour une compréhension intégrée de ces deux approches. Ils nous amènent à souligner la nécessité de construire une présentation du contenu en cause -situations d’optique impliquant à la fois diffraction et imagerie optique -qui soit adaptée à ce public tout en restant cohérente. Quelques germes pour cette construction sont proposés ici : importance de la notion de «groupement de rayons» et raisonnement «par l’aval», c’est-à-dire à partir du point d’observation.
Coordination des «représentations image» et des représentations rationnelles dans la construction du concept d'élément chimique / Coordination of picture representations and rational representations in the building of the concept of chemical element
Authors: Sallaberry Jean-Claude
Published: June 2010

Après repérage de deux catégories de représentations (représentations «image», représentations rationnelles), après une approche de ce qui caractérise un concept scientifique, la construction du concept d’élément chimique est envisagée de deux points de vue : d’abord à partir de la chronique d’une formation en IUFM, ensuite d’un point de vue historique. L’hypothèse du caractère indispensable des représentations image dans l’élaboration du concept est illustrée à partir de leur présence et de leur coordination aux représentations rationnelles.
Étude en inter-didactique des mathématiques et de la physique de l'acquisition de la loi d'Ohm au collège : changement de cadre de rationalité / Study in inter-didactics of mathematics and physics about acquisition of Ohm's law in high school : change of frame
Authors: Malafosse Didier , Lerouge Alain , Dusseau Jean-Michel
Published: June 2010

Ohm’s law is one of the first laws of physics written in mathematical form which pupils find in a french high school. This functional relation is obtained from a discrete number of measurements by a process built on a supposed homomorphism between the concept of proportionality in the mathematical frame, and Ohm’s law in the physical frame. To understand the reasons of the difficulties encountered by pupils in this phase of mathematical modelling, a didactic engineering sequence has been built. The analysis of the experimental results, based on the didactical notions of semiotic register, frame and space of reality interpret these difficulties in term of a break in rationality for three particular elements : the dimensionality of numbers, the transportability of the concept of proportionality and the difference in kind of the laws of ratification.
Des situations-débats pour développer l'argumentation des élèves sur les biotechnologies : compte rendu d'innovation / Debate situations to promote pupils' argumentation on the topic of biotechnology : report of innovation
Authors: Simonneaux Laurence
Published: June 2010

Les biotechnologies ont des champs d’application très variés, de l’industrie chimique à l’agriculture, et du diagnostic médical et de l’industrie pharmaceutique à l’environnement. Leurs répercussions sont sujettes à débats. L’argumentation est au cœur de la construction des savoirs ; elle doit avoir un rôle central en éducation scientifique dans une perspective démocratique. L’enjeu éducatif est de développer les compétences argumentatives des élèves pour qu’ils puissent participer aux débats en tant que citoyens. Cet article situe différents courants théoriques portant sur l’argumentation et présente une méthode d’analyse de stratégies didactiques proposées pour développer l’argumentation des élèves sur les biotechnologies. Cinq exemples supports sont traités. Il s’agit de situations- débats. L’analyse est centrée successivement sur les caractéristiques sociales et sur les procédures préconisées. Il ne s’agit pas de porter un jugement, mais d’essayer de se donner des outils d’analyse permettant aux concepteurs et aux utilisateurs d’étayer leurs choix. Les argumentations des élèves dans deux situations-débats sont étudiées.
Analyse des difficultés des étudiants à propos des concepts de phase et de surface d'onde, du principe de Huygens / Analysis of students' difficulties on the concepts of phase and wave surface, on Huygens' principle
Authors: Maurines Laurence
Published: June 2010

First, this paper focuses on situations of propagation along one direction and on the concept of wave phase. Second, it deals with situations of propagation along several directions (propagation in an inhomogeneous medium, from an extended source, reflection and transmission, superposition of coherent spherical waves) and on the concept of wave surface. The physical quantities to which the students linked these two concepts and the methods they used in order to draw a wave surface are put forward and analysed. The same trends towards a mechanistic reasoning and towards a reduction and materialization of concepts as those previously pointed out are encountered. Some school text-books have been analysed and some pedagogical implications are discussed.
Obstacles épistémologiques et didactiques à la construction du concept d'élément chimique : quelles convergences ? / The epistemological and didactical obstacles in the building of chemical element concept
Authors: Laugier André , Dumon Alain
Published: June 2010

Après une étude épistémologique du savoir de référence destinée à repérer les obstacles rencontrés lors de sa construction, est analysé le comportement d’élèves de seconde (15-16 ans) confrontés à une suite de situations où ces obstacles sont susceptibles de se manifester. Pour les élèves, une substance peut changer de propriétés sans changer d’identité (obstacle perceptif), la molécule est une particule homogène porteuse des propriétés de la substance (obstacle mécaniste), la description au niveau microscopique se déduit de l’observation macroscopique (obstacle réaliste). Des lacunes dans la maîtrise des concepts de base de la chimie rendent le dépassement de ces obstacles difficile.