bluuebunny/crossref_metadata_2025 huggingface dataset:
Granular temperature model for oscillated slurries: A cell model
Authors: Davis M , Koenders M A , Vahid S
Published: October 2008

Diffusive flux models, generally used to describe migration in slurry flow applications are shown to be inadequate for vibrated slurry applications, as in these models the diffusion is linked to a mean shearing flow. As a result they cannot describe a vibrated slurry in the steady state (the zero-motion problem). The granular temperature model by McTigue and Jenkins is able to describe this problem and is therefore suitable for oscillated slurries. The parameters that are required to operate the model are derived from a cell model. Previously they had been set to unity, in the absence of any other clue as to what they might be. In the cell model, developed in this paper, which employs the mean field approximation, the parameters are also found to be of the order of magnitude of unity, but especially the parameter that is associated with dissipation is rather larger than unity. It is shown that this larger parameter leads to a more localized effect in oscillated slurry applications than with the previous estimates. The cell model is verified against viscosity measurements and found to be in good agreement when the number of nearest neighbours is set to six.
Non-linear vibro-impact phenomenon belying transmission idle rattle
Authors: Tangasawi O , Theodossiades S , Rahnejat H , Kelly P
Published: October 2008

This paper investigates automotive transmission gear rattle. Specifically, idle gear rattle, where the repetitive impacts of teeth are subject to light loads is investigated. Hydrodynamic regime of lubrication prevails in lightly loaded impact of teeth pairs. Formation of a lubricant film is due to the combined entraining motion of the lubricant and squeeze film effect. A lumped parameter inertial dynamic model, comprising hydrodynamic impact and flank friction for pairs of simultaneous teeth pairs of loose gears is developed. The overall dynamic model includes seven loose gear pairs and rigid body lateral motions of input and output transmission shafts. Therefore, the influence of fluid film behaviour on idle gear rattle is determined, which has hitherto not attracted sufficient research studies.

Gear rattle is manifested by a vibration signature, which corresponds to the bands of frequencies due to torsional engine oscillations, meshing frequencies, and impact characteristics of lubricated conjunctions. The spectral contributions are affected by lubricant rheology, specifically its bulk viscosity variation with temperature. It has been found that spectral disposition tends towards lower frequency contributions with reducing lubricant viscosity because of rising temperatures and lowering lubricant stiffness. The findings conform with the experimental results, also reported in the paper. It has also been shown that squeeze film motion plays a significant role in the propensity of transmission system to rattle.
Impact fatigue in adhesive joints
Authors: Silberschmidt V V , Casas-Rodriguez J P , Ashcroft I A
Published: October 2008

One of the forms of a vibro-impact effect in engineering components is impact fatigue (IF) caused by a cyclic repetition of low energy, low-velocity impacts, for instance, in aerospace structures. It can have a highly detrimental impact on performance and reliability of such components, exacerbated by the fact that in many cases it is disguised in loading histories by non-impact loading cycles with higher amplitudes. Since the latter are traditionally considered as most dangerous in standard fatigue, IF has not yet received deserved attention; it is less studied and practically unknown to specialists in structural integrity. Though there is a broad understanding of the danger of high-energy single impacts, repetitive impacting of components has been predominantly studied for very short series. This paper aims at the analysis of IF of adhesively bonded joints, which are becoming more broadly used in aerospace applications. The study is implemented for two types of typical adherends — an aluminium alloy and a carbon-fibre reinforced composite — and an industry-relevant epoxy adhesive. Various stages of fatigue crack development in adhesively bonded joints are studied for the conditions of standard and IF. The results obtained — in terms of crack growth rates, fatigue lives, and microstructures of fracture surfaces — are compared for the two regimes in order to find similarities and specific features.
Modelling and analysis of ship roll oscillations interacting with stationary icebergs
Authors: Grace I F , Ibrahim R A
Published: October 2008

Impact dynamic interaction of ships with solid ice or stationary rigid structures is a serious problem that affects the safe operation and navigation in arctic regions. The purpose of this study is to present two analytical models of impact interaction between ship roll dynamics and one-side rigid barrier. These models are the phenomenological modelling represented by a power law in stiffness and damping forces, and Zhuravlev non-smooth coordinate transformation. Extensive numerical simulations are carried out for all initial conditions covered by the ship grazing orbit for different values of excitation amplitude and frequencies of external wave roll moment. The basins of attraction of safe operation are obtained and reveal the coexistence of different response regimes such as non-impact periodic oscillations, modulation impact motion, period-added impact oscillations, chaotic impact motion, and unbounded rotational motion. The results are summarized in the bifurcation diagram in terms of response-excitation amplitudes plane. The stability fraction index is obtained for different values of excitation frequency based on the ratio of the area of bounded roll oscillations to the total area of the grazing orbit.
Periodic motions of a dual-disc rotor system with rub-impact at fixed limiter
Authors: Han Q , Zhang Z , Wen B
Published: October 2008

Periodic motions of a rotor system with two discs are investigated where rub-impacts occur at fixed limiter for a test rig with dual discs. First, a finite element (FE) model of the rotor system is developed. Then numerical simulations based on the FE model are conducted to study the rotor transverse vibrations of the rotor system under three typical cases with different rotating speeds, rub-impact clearances, rub-impact rod stiffness, and rub frictions. The results are further compared with typical multiperiodic characteristics by experimentally measured vibrations. The simulations demonstrate different rotor motions, including periodic, quasi-periodic or complex characteristics, which coincide with experimental measurements. Finally, the non-stationary time-frequency domain characteristics of rub-impact motions are investigated via the Hilbert—Huang transform, and intrinsic mode functions (IMFs) and instantaneous frequencies of the three typical cases are obtained. The research has revealed some of the inherent vibration features of the dual-disc rotor system with rub-impact only occurring at fixed limiters.
Modelling of autoresonant control of ultrasonic transducer for machining applications
Authors: Voronina S , Babitsky V , Meadows A
Published: October 2008

A computer model of a non-linear ultrasonic vibrating system with the possibility of autoresonant control is presented in this paper. The system controlled consists of two modules, the first of which is an electromechanical model of an ultrasonic transducer comprising a piezoelectric transducer and a step concentrator. The second module simulates an influence from the machining process. Coefficients of the electromechanical model and its validity were estimated through an identification process based on the experiments with a real ultrasonic transducer. Further, a numerical model of the autoresonant control of this system has been developed. The autoresonant control maintains the resonant regime of oscillation by means of positive feedback, which provides transformation and amplification of the control signal. The model allows the use and comparison of three control strategies depending on the different electrical and mechanical feedback control signals. The results from simulation and from real machining experiments under different control strategies are compared and discussed.
Dynamics of a beam and a moving two-axle system with separation
Authors: Stâncioiu D , Ouyang H , Mottershead J E
Published: October 2008

The dynamics of a two-axle system travelling along an elastic beam is studied in this paper. A particular aspect that concerns the dynamics of the two structures is that the travelling structure can separate partially or totally from the supporting structure. This phenomenon may induce changes to the response of both structures. In this paper, the separation phenomenon that occurs for a two-axle system moving along a beam is considered. Its influence on the dynamic response of the beam is demonstrated by numerical examples that show the influence of certain parameters on the separation of the travelling structure from the beam. It can be seen that separation may take place at moderate speeds.
Design of a performance-adaptive proportional—integral—derivative controller for stochastic systems
Authors: Yamamoto T , Ohnishi Y , Shah S L
Published: October 2008

In order to manufacture high-quality products it is necessary to regularly monitor the performance of the control loops that regulate the quality variables of interest. This paper describes a design scheme of performance-adaptive controllers which are based on the above control strategy. According to the proposed control scheme, the output prediction error is monitored regularly and system identification is initiated if this error exceeds a user-defined threshold. Subsequently proportional—integral—derivative (PID) parameters are updated for the new model. Optimal PID parameters are calculated based on the linear quadratic Gaussian (LQG) trade-off curve obtained for the reidentified process model. The behaviour of the proposed control scheme is numerically evaluated by some simulation examples.
Stochastic model and synchronization analysis for large-scale oscillator networks and their applications
Authors: Chen X , Zhai G
Published: October 2008

Networks of coupled large-scale oscillators have been studied in biology for a number of years. It has been recognized that transients in the nearest neighbour connected networks may take far too long to die out. It is considered that a few long-distance interconnections exist. Typically, these long-distance interconnections are considered to occur in a random way. In this paper, the synchronization problem for coupled oscillator networks is discussed. Then, the stochastic distribution model for the random long-distance connections is proposed and the validity is demonstrated by simulation. Furthermore, the proposed oscillator network is applied to the visual model of a dragonfly.
Stability analysis of switched linear stochastic systems
Authors: Zhai G , Chen X
Published: October 2008

In this paper, the stability analysis problem is considered for switched linear stochastic systems, where both stable and unstable subsystems are involved, by using the Lyapunov-like function approach. When there is a common Lyapunov-like function for all subsystems, it is shown that the switched system is globally asymptotically stable in probability (GAS-P) if the total activation time ratio of unstable subsystems to stable ones is less than a specified constant. When there is not a common Lyapunov-like function for all subsystems, the proposal is made to use the multiple Lyapunov-like function and to show that in addition to the total activation time ratio requirement, if the average dwell time is sufficiently large, then the switched stochastic system is GAS-P.
Support vector machine-based two-wheeled mobile robot motion control in a noisy environment
Authors: Jiang L , Deng M , Inoue A
Published: October 2008

In this paper, a support vector machine (SVM)-based control scheme of a two-wheeled mobile robot is proposed in a noisy environment. The noisy environment is defined as the measured data with uncertainty. The proposed control scheme can control the robot by consideration of local minima, where the controller is based on the Lyapunov function candidate and considers virtual force information. The SVM method is used for estimating the control parameters from the noisy environment. Four simulation results are presented to show the effectiveness of the proposed control scheme in the noisy environment, while the performance of a former method degrades significantly.
Stochastic feedforward—feedback control design in a discrete-time case
Authors: Dallagi A , Forbes J , Forbes M G , Guay M
Published: October 2008

This paper examines the role of random feedforward inputs in a probabilistic framework for stochastic control design in a discrete-time case. Fundamental rules of probability are applied to extend the Chapman—Kolmogorov equation by including the effect of the additional random disturbance variables. The steady state solution to this equation is then applied to the design of two long-term regulatory controllers: a probability-density-shaping controller and an approximation of an optimal controller with respect to a non-symmetric and non-quadratic cost functions.
Neural controllers for networked control systems based on minimum tracking error entropy
Authors: Zhang J H
Published: October 2008

In this paper, a novel proportional—integral—derivative (PID) feedback control method for networked control systems (NCSs) subject to random delays is presented via minimizing tracking error entropy, which is estimated by Parzen windows and quadratic Gaussian kernels. The PID controller is implemented by backpropagation (BP) neural networks. Specifically, the performance index implies the idea of the minimum entropy control of the closed-loop tracking error. The convergence in the mean square sense has been analysed for closed-loop NCSs. Simulation results are provided to show the effectiveness of the proposed approach.
Adaptive observer-based non-linear stochastic system control with sliding mode schemes
Authors: Qiao F , Zhu Q M , Liu J , Zhang F
Published: October 2008

In this paper, an adaptive sliding mode observer is designed to reconstruct the states of non-linear stochastic systems with uncertainties from the measurable system output and the reconstructed states are employed to construct a sliding mode controller for the stabilization control of complex non-linear systems. It takes the advantages of the sliding mode schemes to design both the observer and the controller. The convergence of the observer and the globally asymptotical stability of the controller are analysed in terms of stochastic Lyapunov stability, and the effectiveness of the control strategy is verified with numerical simulation studies.
Triple helix circulation: the heart of innovation and development
Authors: Dzisah James , Etzkowitz Henry
Published: October 2008

The premise of triple helix circulation is that movement of people around the spheres enhances creativity, ideas and skills. Universities, the traditional providers of human resources and knowledge, are now critical socio-economic development actors. Removing the blockages to circulation
and enhancing interaction and cooperation among development actors and agencies is the development challenge of the 21st century. Sustainable knowledge-based development is the objective of all societies in an interdependent era characterized by resource constriction and efflorescence of science
and technology.
Environmental policy and industrial response in Nigeria
Authors: Adeoti John Olatunji
Published: October 2008

The debate on environmental regulation and industrial competitiveness of developing countries rages on with no easy solution to the micro-level problems it poses to firms. The discourse in this article demonstrates that firms' responses to environmental policy are influenced by local
and foreign environmental regulatory regimes and the perceived sustainability objectives that firms pursue. The empirical illustrations drawn from a survey of Nigerian firms showed that a weak environmental policy regime might not be a deterrent to significant technology responses for pollution
control. However, this does not imply that environmental policy should not be strengthened or enforced with more rigour. Rather, the empirical cases demonstrated that firms' decisions to respond are influenced by the intricate links between the prevailing regime of environmental policy under
which firms are operating and the economic, social and environmental motives of firms. The findings suggest that policies aimed at promoting environmentally friendly behaviour of industrial firms should not be limited to environmental policy. Equally important are technology and industrial
policies which are also capable of promoting ecological objectives.
Waste handling model and practices used at red meat abattoirs in the Free State province, South Africa
Authors: Roberts Hester , De Jager L
Published: October 2008

Despite legislation governing the handling of red meat abattoirs waste in South Africa, irregularities still occur. Economic conditions in South Africa force under-privileged communities to scavenge on landfill sites, dumping grounds and abattoir disposal sites. Condemned products/carcasses
are eaten by scavengers which could lead to significant health problems, disease and death. The waste products generated and the waste disposal strategies used was determined. A condemned product waste handling model was developed, causing minimum environmental pollution, reducing health risks
and adding value to these products. Waste handling practices of 78 red meat abattoirs were determined by administering questionnaires and site visits. Most condemned products were buried/burned whereas most blood was disposed of into municipal drainage systems with the waste water. Limited
by-product processing, denaturing and incineration took place. Minimal amounts of stomach contents and manure were utilized as compost but were mostly dumped on municipal landfill sites or farm land.
A la recherche d'un essaimage russi sans douleur: Cas d'une grande entreprise publique minire Tunisienne
Authors: Daly Faycel , Abdallah Laroussi Ben
Published: October 2008

Le phnomne d'essaimage ou de spin-off est le rsultat d'un changement conomique, politique, socio-culturel et idologique. L'objectif de ce papier est de dmontrer que la russite de l'opration d'essaimage est conditionne par l'existence de certains pralables. Il s'agit principalement de la nature du capital relationnel dtenu par le dirigeant de l'entreprise essaime et la personnalit de ce dernier. Pour cela, notre tude sera articule autour de trois grandes parties. La premire partie nous permettra d'identifier et de bien cerner le concept d'essaimage travers une revue synthtique et critique des diffrentes approches thoriques en prsence. La deuxime partie aura pour but d'valuer la capacit du contexte tunisien favoriser l'mergence de cette forme d'entrepreneuriat. La troisime partie portera sur une tude comparative de deux cas d'entreprises essaimes partir d'une des plus grandes entreprises tunisiennes : La Compagnie des Phosphates de Gafsa.
Book Reviews
Authors: Dris Cherif
Published: October 2008

North African Immigrant Businessmen: From Stigmatisation to Social Recognition, Mohammed Madoui (2008)

Montreil, Paris, France: Aux lieux d'tre, 190 pp., ISBN 978-2-916863-55-3 (pbk), 19.90
Cinematic perspectives on the war on terror: The Road to Guantnamo (2006) and activist cinema
Authors: Bennett Bruce
Published: October 2008

Starting from the premise that Michael Winterbottom's films exemplify a certain model of transnational cinema, because they are made with international crews and casts, shot on location around the world, financed by transnational capital, and concerned with questions of borders, immigration,
imperialism and identity, this article offers a close analysis of The Road to Guantnamo (2006) in order to set out the kind of political practice it claims Winterbottom's cinema enacts. The Road to Guantnamo appears to have been conceived as a very precise and partial intervention
in the mediated public sphere: it was released simultaneously in cinemas, on broadcast television, on DVD and over the internet for streaming and downloading. By addressing multiple and overlapping publics in this particularly direct way, the film was revealing its partial and contestatory
status, a status deriving as much from the multiple media of its transmission as from its content. Offering a close analysis of the heterogeneous composition of The Road to Guantnamo and the striking coolness and neutrality of its style of docudrama (also characteristic of Winterbottom's
other films), the article concludes that the film may refrain from political affect because of its concern with political effects, and addresses specific and informed publics in a new type of political practice made possible by transnational media and a recently transnationalized public sphere.
Reviews
Authors: Loxham Abigail , Castro Paul Melo e , Brown William
Published: October 2008

Projecting Migration: Transcultural Documentary Practice, Alan Grossman and Aine O'Brien (eds.) (2007) London: Wallflower Press, 224 pp., ISBN 978-1-905674-04-6 (pbk + DVD-ROM), 29.95.

Brazilian National Cinema, Lisa Shaw and Stephanie Dennison (2007)
London and New York: Routledge, 223 pp., ISBN 978-0-415-33816-5 (pbk), 17.99

European Cinemas in the Television Age, Dorota Ostrowska and Graham Roberts (2007) Edinburgh: Edinburgh University Press, 191 pp., ISBN 978-0-7486-2309-9, 16.99
French cinema in exile: trans-national cultural representation in Tony Gatlif's Gadjo Dilo
Authors: McGregor Andrew
Published: October 2008

This article explores the notion of cultural authenticity that is a key element of both the narrative and the meta-narrative of Tony Gatlif's 1998 film Gadjo Dilo. The film's young French protagonist seeks to sample Romani (Gypsy) culture by means of a high-quality DAT recording
of the singer Nora Luca, only to discover by the film's end that such an endeavour is a futile exercise in Western orientalist fantasy. With a focus on Western European and American critical responses to the film, as well as on the marketing of the film in those regions, the article argues
that Gatlif's claims to cultural authenticity as an indigenous gypsy filmmaker function in much the same way as the delusions of his protagonist. Presented by Gatlif as a sample of the truth of Romani cultural identity, the film becomes the kind of problematic cultural artefact that the director
seeks to expose within the narrative of his film.
S1′ and S2′ subsite specificities of human plasma kallikrein and tissue kallikrein 1 for the hydrolysis of peptides derived from the bradykinin domain of human kininogen
Authors: Lima Aurelio Resende , Alves Fabiana M. , Ângelo Pedro Francisco , Andrade Douglas , Blaber Sachiko I. , Blaber Michael , Juliano Luiz , Juliano Maria Aparecida
Published: October 2008

The S1′ and S2′ subsite specificities of human tissue kallikrein 1 (KLK1) and human plasma kallikrein (HPK) were examined with the peptide series Abz-GFSPFRXSRIQ-EDDnp and Abz-GFSPFRSXRIQ-EDDnp [X=natural amino acids or S(PO3H2)]. KLK1 efficiently hydrolyzed most of the peptides except those containing negatively charged amino acids at P1′ and P2′ positions. Abz-GFSPFRSSRIQ-EDDnp, as in human kininogen, is the best substrate for KLK1 and exclusively cleaved the R-S bond. All other peptides were cleaved also at the F-R bond. The synthetic human kininogen segment Abz-MISLMKRPPGFSPFRS390S391RI-NH2was hydrolyzed by KLK1 first at R-S and then at M-K bonds, releasing Lys-bradykinin. In the S390and S391phosphorylated analogs, this order of hydrolysis was inverted due to the higher resistance of the R-S bond. Abz-MISLMKRPPG-FSPFRSS(PO3H2)391RI-NH2was hydrolyzed by KLK1 at M-K and mainly at the F-R bond, releasing des-(Arg9)-Lys-Bk which is a B1 receptor agonist. HPK cleaved all the peptides at R and showed restricted specificity for S in the S1′ subsite, with lower specificity for the S2′ subsite. Abz-MISLMKRPPGFSPFRSSRI-NH2was efficiently hydrolyzed by HPK under bradykinin release, while the analogs containing S(PO3H2) were poorly hydrolyzed. In conclusion, S1′ and S2′ subsite specificities of KLK1 and HPK showed peculiarities that were observed with substrates containing the amino acid sequence of human kininogen.
An efficient fluorimetric method to measure the viability of intraerythrocytic Plasmodium falciparum
Authors: Evers Astrid , Heppner Saskia , Leippe Matthias , Gelhaus Christoph
Published: October 2008

A range of various assays to measure chemosusceptibility of Plasmodium falciparum have been described in the literature. As the screening of a plethora of compounds for antiplasmodial activity is urgently needed and becomes a constantly increasing routine analysis, a test system has to fulfill the following requirements: sensitivity, reliability, simplicity of performance, high-throughput compatibility, and cost-effectiveness. Here, we describe an assay that fulfills all criteria and in which the fluorescent SYTOX® Green dye is introduced to determine growth inhibition of Plasmodia in in vitro cultures.
Interaction of angiotensin-converting enzyme (ACE) with membrane-bound carboxypeptidase M (CPM) – a new function of ACE
Authors: Sun Xiaoou , Wiesner Burkhard , Lorenz Dorothea , Papsdorf Gisela , Pankow Kristin , Wang Po , Dietrich Nils , Siems Wolf-Eberhard , Maul Björn
Published: October 2008

Angiotensin-converting enzyme (ACE) demonstrates, besides its typical dipeptidyl-carboxypeptidase activity, several unusual functions. Here, we demonstrate with molecular, biochemical, and cellular techniques that the somatic wild-type murine ACE (mACE), stably transfected in Chinese Hamster Ovary (CHO) or Madin-Darby Canine Kidney (MDCK) cells, interacts with endogenous membranal co-localized carboxypeptidase M (CPM). CPM belongs to the group of glycosylphosphatidylinositol (GPI)-anchored proteins. Here we report that ACE, completely independent of its known dipeptidase activities, has GPI-targeted properties. Our results indicate that the spatial proximity between mACE and the endogenous CPM enables an ACE-evoked release of CPM. These results are discussed with respect to the recently proposed GPI-ase activity and function of sperm-bound ACE.
T-SP1: a novel serine protease-like protein predominantly expressed in testis
Authors: Neth Peter , Profanter Birgit , Geissler Claudia , Nägler Dorit K. , Nerlich Andreas , Sommerhoff Christian P. , Jochum Marianne
Published: October 2008

Here, we describe a novel member in the group of membrane-anchored chymotrypsin (S1)-like serine proteases, namely testis serine protease 1 (T-SP1), as it is principally expressed in testis tissue. The human T-SP1 gene encompasses 28.7 kb on the short arm of chromosome 8 and consists of seven exons. Rapid amplification of cDNA ends (RACE) experiments revealed that due to alternative splicing three different variants (T-SP1/1, -2, -3) are detectable in testis tissue displaying pronounced heterogeneity at their 3′-end. T-SP1/1 consists of an 18 amino acid signal peptide and of a 49 amino acid propeptide. The following domain with the catalytic triad of His108, Asp156, and Ser250shares sequence identities of 42% and 40% with the blood coagulation factor XI and plasma kallikrein, respectively. Only T-SP1/1 contains a hydrophobic part at the C-terminus, which provides the basis for cell membrane anchoring. Using a newly generated polyclonal anti-T-SP1 antibody, expression of the T-SP1 protein was found in the Leydig and Sertoli cells of the testis and in the epithelial cells of the ductuli efferentes. Notably, T-SP1 protein was also detectable in prostate cancer and in some ovarian cancer tissues, indicating tumor-related synthesis of T-SP1 beyond testis tissue.
Quantitative expression analysis and prognostic significance of the novel apoptosis-related gene BCL2L12 in colon cancer
Authors: Kontos Christos K. , Papadopoulos Iordanis N. , Scorilas Andreas
Published: October 2008

Apoptosis is a tightly regulated process that plays a critical role in many biological events. Members of the BCL2 (Bcl-2) family of apoptosis-related genes have been found to be differentially expressed in various malignancies and have been proposed as prognostic tumor biomarkers. We have recently discovered and cloned a new member of the BCL2 gene family, BCL2L12, expressed in colon tissues. Here we have investigated expression of the BCL2L12 gene in colon cancer tissues and assessed its prognostic value. Total RNA was isolated from 96 specimens of malignant colon tissue. After testing the RNA quality, cDNA was prepared by reverse transcription. A highly sensitive real-time PCR method for BCL2L12 mRNA quantification was developed using SYBR® Green chemistry. GAPDH served as a housekeeping gene. Relative quantification analysis was performed using the comparative CT method (2-ΔΔCT). High BCL2L12 expression levels were found in smaller (≤5 cm, p=0.027) and well-differentiated tumors (p=0.034), as well as in early-stage tumors (p=0.039). Survival analysis demonstrated that patients with BCL2L12-positive colon tumors have significantly longer disease-free survival and overall survival (p=0.015 and p=0.027, respectively). Our results suggest that BCL2L12 gene expression may represent a potential new biomarker for colon cancer.
Reflections on the tissue kallikrein and kallikrein-related peptidase family – from mice to men – what have we learnt in the last two decades?
Authors: Clements Judith A.
Published: October 2008

The genes encoding the kininogenase, glandular tissue kallikrein, in rodents and man were first described in the mid-1980s. Remarkably, they appeared to be part of a much larger highly conserved family of genes (GK) in rodents, but only had two paralogs in man. This discrepancy was not rectified until the late 1990s/2000 with the identification of a cluster of 12 more kallikrein-related (KLK) genes in the human 19q13 locus and the subsequent identification of their rodent homologs. Interestingly, there are remarkable similarities in expression patterns, hormonal regulation and functional attributes of the old (GK) and new (KLK) families which underscore the evolutionary conservation across these loci and species. This historical perspective focuses on the lessons learned from earlier studies on the rodentGKgene families and the striking similarities of some attributes, yet uniqueness, of others. These earlier findings have all contributed to the current status of the KLK serine peptidase-encoding gene family as an exciting source of new biomarkers and therapeutic targets.
50 Jahre Zentrale Stelle in Ludwigsburg. Ein Erfahrungsbericht über die letzten zweieinhalb Jahrzehnte
Authors: Schrimm Kurt , Riedel Joachim
Published: October 2008

Vorspann

Die Zentrale Stelle in Ludwigsburg ist das Herzstück der justiziellen Ahndung von NSVerbrechen. 1958 gegründet, spielte die einzigartige Institution bei der Einleitung fast aller großen Prozesse eine wichtige Rolle. Der jetzige Leiter und sein Stellvertreter ziehen hier Bilanz und blicken dabei vor allem auf die letzten 25 Jahre zurück, in denen die Zentrale Stelle dazu überging, umfassende eigenständige Ermittlungen im In- und Ausland durchzuführen – und dabei immer wieder beachtliche Erfolge verbuchen konnte.
Sowjetische Kriegsgefangene in deutschem Gewahrsam 1941–1945. Zahlen und Dimensionen
Authors: Otto Reinhard , Keller Rolf , Nagel Jens
Published: October 2008

Vorspann

Die sowjetischen Kriegsgefangenen stellen nach den Juden die zweitgrößte Opfergruppe nationalsozialistischer Vernichtungspolitik dar. Die Gesamtzahl der sowjetischen Soldaten in deutscher Hand und die genaue Zahl der Opfer sind jedoch noch immer nicht bekannt. Auf der Grundlage neu erschlossener personenbezogener Quellen und langjähriger Studien gelingt es den Autoren, für den Zuständigkeitsbereich des OKW exakte Zahlen zu ermitteln und nachzuweisen, dass immerhin 2,8 Millionen sowjetischer Kriegsgefangener individuell registriert worden sind, so dass sich deren Schicksal genauer nachvollziehen lässt.
Hitler und sein Stoßtrupp in der Reichskristallnacht
Authors: Hermann Angela
Published: October 2008

Vorspann

Die Urheberschaft für die antisemitischen Pogrome des 9. November 1938 wurde in der Forschung lange Reichspropagandaminister Joseph Goebbels zugeschrieben. Angela Hermann, langjährige Mitarbeiterin der Goebbels-Edition des Instituts für Zeitgeschichte und mit quellenkritischen Studien zu den Goebbels-Tagebüchern jüngst promoviert, kann nun aber nachweisen: Nicht der Propagandaminister, sondern in erster Linie Hitler selbst und dessen seit 1923 legendärer „Stoßtrupp“ waren für die sogenannte „Reichskristallnacht“ verantwortlich.
Die Strafverfolgung von NS-Verbrechen durch westdeutsche Justizbehörden seit 1945. Eine Zahlenbilanz
Authors: Eichmüller Andreas
Published: October 2008

Vorspann

Bilanzen leben von Zahlen – und die waren unsicher. Dieser Mangel warum so schmerzlicher, als er sich auf die Intensität von Strafverfolgung von NS-Verbrechen und damit auf ein besonders sensibles Kapitel der deutschen Geschichte bezog. Andreas Eichmüller, Wissenschaftler am Institut für Zeitgeschichte, schafft hier Abhilfe, wobei er sich auf umfassende neuere Forschungen im Rahmen eines Kooperationsprojekts mit der Holocaust-Gedenkstätte Yad Vashem stützen kann.
Staat im Staate? Zur Kooperation von Reichswehr und Republik in der Frage des Grenz- und Landesschutzes
Authors: Bergien Rüdiger
Published: October 2008

Vorspann

Wie weit stützte die Weimarer Republik die geheimen Rüstungs- und Mobilmachungsvorbereitungen der Reichswehr? Handelten die Militärs nur im eigenen Interesse oder konnten sie auf eine Rückendeckung von Staat und Verwaltung vertrauen? Dokumentenfunde im polnischen Wojwodschaftsarchiv in Posen lassen die Beziehungen zwischen Reichswehr, Politik und Administration in einem neuen Licht erscheinen.
Effects of oligofructose containing diet in obese persons
Authors: Antal Magda , Regöly-Mérei Andrea , Biró Lajos , Arató Györgyi , Schmidt Judit , Nagy Katalin , Greiner Erika , Lásztity Natália , Szabó Csaba , Péter Szabolcs , Martos Éva
Published: October 2008

Az elhízás kezelésében az egyik alapvető követelmény az energiaszegény étrend bevezetése. Az ételek rosttartalmának növelése az éhségérzet csökkentésével hozzájárulhat a diéta betartásához. Az oligofruktózok az élelmi rostok csoportjába tartoznak.
Célkitűzés:
Oligofruktóz-tartalmú csicsókasűrítménnyel kiegészített, csökkentett energiaértékű étrend (2000 kcal/nap) hatásának tanulmányozása elhízott serdülők és felnőttek diétás kezelésében.
Módszerek:
Tizenkét elhízott tanuló (6 fiú és 6 lány) és 6 nő csökkentett energiaértékű étrendet fogyasztott 12 héten keresztül, míg 16 elhízott tanuló (10 fiú és 6 lány) és 17 nő a csökkentett energiaértékű étrendet 14 g/nap oligofruktóz-tartalmú csicsókasűrítménnyel készült termékekkel együtt fogyasztotta. Kiértékeltük a teltségérzetet, és meghatároztuk az antropometriai paraméterek mellett a lipid- és a szénhidrát-anyagcsere biomarkereit és az adipokinek szérumkoncentrációját.
Eredmények:
A csicsókasűrítménnyel kiegészített csökkentett energiaértékű étrend hatására csökkent az éhségérzet, szignifikánsan csökkent a testtömegindex és a testzsírszázalék, valamint javult a lányok és a nők szérumában a trigliceridszint és a homeosztázismodell alapján mért inzulinrezisztencia mértéke.
Következtetés:
Az elővizsgálat szerint az új technológiai eljárással készült csicsókasűrítmény beiktatása az étrendbe a dietoterápia ígéretes komponensének tűnik.
The clinical relevance of experimental acute pancreatitis models
Authors: Takács Tamás , Szabolcs Anna , Biczó György , Hegyi Péter , Rakonczay Zoltán
Published: October 2008

Az akut pancreatitis klinikai diagnosztikájának és kezelésének mai gyakorlata több évtizedes kísérletes és humán vizsgálatok eredményeként alakult ki. Az elmúlt évtizedekben számos állatkísérletes pancreatitismodellt dolgoztak ki, amelyek lehetőséget adtak a betegség etiopatogenezisének tanulmányozására, a gyulladásos folyamatok helyi és távoli szövődményeinek vizsgálatára és az esetleges terápiás hatású vegyületek, gyógyszerek előzetes tesztelésére. A heveny hasnyálmirigy-gyulladás patomechanizmusának számos aspektusa, így mindenekelőtt a betegség korai fázisának tanulmányozása kizárólag állatkísérletes vizsgálatokkal lehetséges. Az utóbbi években a molekuláris genetikai módszerek lehetővé tették azt is, hogy kísérletes körülmények között a gyulladásos folyamatokban részt vevő mediátorok géntechnológiai módosításával kiiktassuk vagy éppen felerősítsük azok hatásait. Nem kétséges ugyanakkor, hogy az experimentális pancreatitismodellekben kapott eredmények csak korlátozott mértékben tükrözik a humán pancreatitis során történteket. Ennek ellenére jelenleg úgy tűnik, hogy a klinikai pankreatológia fejlődésében nem nélkülözhetjük az állatkísérletes vizsgálatok során nyerhető tudományos eredményeket.
Atrial fibrillation and the autonomous nervous system
Authors: Lőrincz István , Szabó Zoltán , Simkó József , Szánthó Eszter , Barta Kitti , Füzi Márta , Szigeti Gyula
Published: October 2008

A vegetatív idegrendszer fontos és döntő szerepet játszik a pitvarfibrilláció kialakulásában, fenntartásában, fennmaradásában és megszűnésében. Az autonóm tónus befolyásolhatja az aritmia szubsztrátját és a triggermechanizmusokat. Összefoglaló munkánkban áttekintjük a vegetatív idegrendszer és a pitvarfibrilláció kapcsolatát, leírjuk a speciális neuroanatómiai viszonyokat, ismertetjük a baroreflex és más autonóm reflexek szerepét a pitvarfibrilláció elindításában, fenntartásában és megszűnésében. Kitérünk továbbá arra, hogy a pitvarfibrilláció kuratív gyógyítására alkalmazott percutan katéterablatio, a pulmonalis vénák izolációjának kiegészítése neuroablatióval hogyan és milyen mechanizmusok alapján befolyásolhatja ezen autonóm hatásokat s azok következményeit. Befejezésül kísérletet teszünk a gyógyszeres terápia összefoglalására. A vagális és adrenerg pitvarfibrilláció elkülönítése napjainkban még csak igen csekély terápiás konzekvenciával jár.
Capsule endoscopy for the diagnostics of small intestine tumours
Authors: Kovács Márta , Pák Péter , Pák Gábor , Fehér János
Published: October 2008

A vékonybélben alakul ki az összes gastrointestinalis tumor 3-6%-a és a gastrointestinalis rosszindulatú tumorok 1-2%-a. Gyakrabban fordulnak elő férfiaknál, mint nőknél, és a gyakoriság csúcsa az 50–60. életév közé esik. Az eddigi epidemiológiai vizsgálatok alapján leggyakrabban adenocarcinomák, carcinoid tumorok, lymphomák és stromatumorok alakulnak ki primeren a vékonybélben. A tumorok hisztológiai típusától függetlenül klinikai megjelenésükben azonosak. A benignus tumorok 50%-a aszimptomatikus, és mellékleletként sectio során derül csak fény jelenlétükre. Ezzel szemben a malignus daganatok 80%-a tünetképző. A vékonybél rosszindulatú daganatainak prognózisa igen rossz, mert a diagnózis felállításakor már 45-75%-ban áttétet képeznek, és a műtéti beavatkozás időpontjában 20-50%-uk irreszekábilis. A késői diagnózis oka egyrészt a korai tünetek aspecifikussága, másrészt a hagyományos radiológiai és endoszkópos módszerekkel a teljes vékonybél vizualizálásának korlátozott volta. A kapszulás endoszkópia forradalmasította a vékonybél-diagnosztikát, mert segítségével lehetővé vált a teljes vékonybél noninvazív, fájdalmatlan vizsgálata. A tumordiagnosztikában a kapszulás endoszkópia kellő időben történő alkalmazása esetén számos, alacsony diagnosztikus értékű és költséges vizsgálat takarítható meg. Az eddig elvégzett vizsgálatok alapján a vékonybéltumorok prevalenciája magasabb, mint ahogy ezt a korábbi epidemiológiai vizsgálatok alapján becsülték. Az új módszer korai diagnózist és definitív terápiát eredményez, és ezzel a betegek túlélése jelentősen javulhat.
Osteoprotegerin: regulator, protector and marker
Authors: El Hadj Othmane Taha , Speer Gábor , Fekete Bertalan , Szabó Tamás , Egresits József , Fodor Erzsébet , Kiss István , Nemcsik János , Szabó András , Németh Zsófia , Szathmári Miklós , Tislér András
Published: October 2008

A csontbiológia terén végzett vizsgálatok vezettek a tumornekrózis-faktorok családjába tartozó receptorok, így az osteoprotegerin és a receptor activator of nuclear factor κB (RANK) szerepének tisztázásához a csontátépülés folyamatának szabályozásában. A RANK receptor ligandja (RANKL) a csontreszorpció stimulátora, míg az osteoprotegerin a csont keringő, szolúbilis protektora. A csontátépülés kóros állapotai (így az osteoporosis is) összefüggnek az osteoprotegerin és a RANKL közti egyensúlyi állapot megbomlásával. Az elmúlt évek eredményei rámutattak arra is, hogy az osteoprotegerin/RANKL/RANK rendszer fontos szerepet játszik az immun- és a vascularis rendszer szabályozásában. Közleményünkben az elsődlegesen „csontprotektor” hatásúként megismert osteoprotegerin funkcióját, szabályozását és patológiás állapotokban – döntően a cardiovascularis megbetegedésekben – játszott szerepét, rizikómarkerként való alkalmazhatóságát foglaljuk össze. Végül krónikus hemodializált betegeink között végzett prospektív vizsgálatunkat ismertetjük, amelyben az ezen betegek cardiovascularis mortalitása, OPG-szérumszintje és érfali tágulékonysága közti összefüggést vizsgáltuk – pozitív eredménnyel.
Fish Passage in a Western Iowa Stream Modified by Grade Control Structures
Authors: Litvan Mary E. , Pierce Clay L. , Stewart Timothy W. , Larson Chris J.
Published: October 2008

Grade control structures (GCSs) are commonly used in streams of western Iowa to control bank erosion and channel headcutting but may be barriers to fish passage. From May 2002 to May 2006, we used mark–recapture methods to evaluate fish passage over a total of five GCSs, ranging in slope (run : rise) from 13:1 to 18:1 in Turkey Creek, Cass County, Iowa. Three structures, over which limited fish movement was documented from 2002 to 2004, were modified in the winter of 2004–2005 to facilitate fish passage. Before modification, the majority of recaptured fish were recaptured at the station where they were originally marked; only 1% displayed movement between sites and either upstream or downstream over a GCS. After modification fish passage improved, 14% of recaptured fish displayed movement either upstream or downstream over a GCS. Individuals of four target species—channel catfish Ictalurus punctatus, yellow bullhead Ameiurus natalis, black bullhead A. melas, and creek chub Semotilus atromaculatus—passed over at least one modified structure. The majority of documented movements over GCSs were in the upstream direction and occurred in late spring and early summer, when streamflow was relatively high. Although we documented low numbers of fish passing both upstream and downstream over GCSs, these structures are probably barriers to fish movement during periods of low flow and when there is a structural failure, such as in-channel movement of riprap. Grade control structures are pervasive in western Iowa streams; nearly every low-order stream contains at least one instream structure. To sustain fish populations, management efforts should focus on constructing or modifying GCSs to allow fish passage.
Predictive Value of a Lake Sturgeon Habitat Suitability Model
Authors: Haxton Tim J. , Findlay C. Scott , Threader R. W.
Published: October 2008

Although many fish habitat suitability models (HSMs) have been developed and used in wildlife management and conservation planning, comparatively few have been independently validated. Given the importance of such models in habitat management and conservation policy, the extent to which they accurately predict population parameters (e.g., abundance or recruitment) is a critical issue. Here we apply an HSM recently developed for lake sturgeon Acipenser fulvescens in northern rivers to three reaches of the Ottawa River, using measurements of the model's key variables (substrate type, water depth, and velocity) to generate spatially explicit predictions of habitat suitability. We then test the predictive power of the model by comparing lake sturgeon catch per unit effort (CUE) when using short-set gill nets in areas predicted to have good (habitat suitability index values >0.6) and poor (values < 0.3) adult and juvenile foraging habitats. Consistent with model predictions, significantly more lake sturgeon were caught at sites within river reaches predicted to be of high quality than at those predicted to be of low quality. Moreover, the average CUE at the reach scale correlated positively with the average predicted habitat foraging quality. On the other hand, the predictive power was generally low, such that most of the variation in CUE was unexplained by the fitted models. These results suggest that although the lake sturgeon HSM developed for northern rivers has some predictive power in other contexts, the uncertainty of its predictions is still rather high. We suggest that (1) considerably more effort be devoted to the independent validation of both existing HSMs and those still in development and (2) in the absence of independent validation and bona fide estimates of their predictive power, such models be used circumspectly in conservation management and planning.
Impact of hydromorphology and spatial scale on macroinvertebrate assemblage composition in streams
Authors: Verdonschot Piet FM
Published: October 2008

Stream risk assessment and restoration requires understanding of the controlling factors and the scale at which they act. The role of hydromorphology, along with physicochemistry, was for a long time neglected, and scale issues were barely tackled. In this study, both the role of hydromorphology and the relevance of scale are studied. For this purpose, the macroinvertebrate community of the stream is used as the scale of the target biota. Next, the following research question is dealt with: At which scale, and to what extent, do hydrology and morphology along with physicochemistry explain stream macroinvertebrate distribution? Three data sets were used: The European AQEM study, the Dutch streams study, and an extensive habitat-preference study. Ordination was used to relate the macroinvertebrate species composition to the (hydromorphological) environment for both the European study and the Dutch stream study data. To explore the strength of one or more variables in explaining the macroinvertebrate distribution over the sampling sites, the fraction of the sum of canonical eigenvalues was used as a measure. To determine the preference for a specific habitat type of each macroinvertebrate species in the habitat preference study, the index of representation was calculated. The European study showed that streams within a more limited geographic area tend to carry macroinvertebrates whose distribution is better explained by stream stretch and in-stream variables. However, even within stream type catchment and stream valley, variables almost equally add to the explanation of the macroinvertebrates distribution. The explanatory power of hydrological and physicochemical variables increased toward smaller scales, and morphological variables showed an equal explanatory power over the different scales. In the Dutch streams study, stream level was much better explained in comparison to the habitat level. Geographical, morphological, and physicochemical variables were strong explanatory variables. For both habitat and stream, the stream stretch variables contributed most to the explanation of macroinvertebrate distribution, whereas microhabitat variables were less explanatory. The habitat preference study supported the observation that habitat provided less explanation than stream stretch. Only 15% of the macroinvertebrate species showed a clear habitat preference; none showed an obligatory one. In conclusion, stream macroinvertebrates distribution is best explained by local stream-stretch variables, provided those variables are contained within a catchment and stream valley context. Differences in vulnerability and biotic capacity between macroinvertebrate species determine the assemblage present. Applying this knowledge in water management means that any risk assessment and restoration effort needs a hydromorphological context.