bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of the Mass Sensitivity of Phage-Coated Magnetoelastic Biosensors for the Detection of Single Pathogenic Bacteria
Authors: Horikawa Shin , Li Suiqiong , Chai Yating , Petrenko Valerly A. , Chin Bryan A.
Published: May 2011

Freestanding, strip-shaped magnetoelastic (ME) biosensors are a class of wireless, mass-based biosensors that are being developed for the real-time detection of pathogenic bacteria for food safety and bio-security. The mass sensitivity of these biosensors operating in longitudinal-vibration modes is known to be largely dependent on the position of masses attached to the sensor surfaces. Hence, considering this dependence is crucial to the detection of low-concentration target pathogens, including single pathogenic bacteria, because their local attachment may cause varying sensor responses. In a worst case scenario, the resultant sensor responses (i.e., mass-induced resonance frequency changes of the sensor) may be too small to be detected despite the attachment of the target pathogenic masses. To address the issue, phage-coated ME biosensors (magnetostrictive strips (4 mm × 0.8 mm × 30 μm) coated with a phage probe specifically binding streptavidin protein) with localized masses (streptavidin-coated polystyrene beads) were fabricated, and mass-position-dependence of the sensor’s sensitivity under the fundamental-mode vibration was experimentally measured. In addition, three-dimensional finite element (FE) modal analysis was performed using the CalculiX software to simulate the phenomena. The experimental and theoretical results show close agreement: (1) the mass sensitivity was low when the mass was positioned in the middle of the sensor’s longest dimension and (2) a much higher mass sensitivity was, by contrast, obtained for the equivalent masses placed at both ends of the strip-shaped sensor. Furthermore, FE models were constructed for differently sized, phage-coated ME biosensors (100 – 500 μm in length with different widths and thicknesses) loaded with a single bacterial mass (2 μm × 0.4 μm × 0.4 μm, 1.05 g/cm3) at varying longitudinal positions. The mass sensitivity was found to be approximated by a mass-position-dependent Boltzmann function whose amplitude is inversely proportional to the length squared, width, and thickness of the sensor.
Endogenous Institution in Decentralization
Authors: Azis Iwan J
Published: May 2011

Decentralization policy by itself is not a panacea for problems of accountability. A model is developed to exemplify a condition whereby given widespread 'capture’ in local elections, voices or people’s participation stands out as the most important factor that determines whether the decentralization system produces positive or negative local capture. The size of local budget and the initial welfare condition matter as well. The latter can also explicate the persistent gap between poor and rich regions observed in many countries. The welfare effect of the policy depends on the behavior and quality of local leader that govern the interplay of the above factors. The model can thus produce multiple equilibria. To the extent that the quality and behavior of local leader play a critical role, a three-player coordination game is constructed to reflect the hypothesis postulated by the theory of endogenous institution.
Besselian g-frames and near g-Riesz bases
Authors: Abdollahpour M.R. , Najati A.
Published: May 2011

In this paper we introduce and study near g-Riesz basis, Besselian g-frames
and unconditional g-frames. We show that a near g-Riesz basis is a Besselian
g-frame and we conclude that under some conditions the kernel of associated
synthesis operator for a near g-Riesz basis is finite dimensional. Finally,
we show that a g-frame is a g-Riesz basis for a Hilbert space H if and only
if there is an equivalent inner product on H, with respect to which it
becomes an g-orthonormal basis for H.
Kinetic of sintering of polyethilene glycol and lanthanum dopped aluminum oxide obtained by the sol-gel method
Authors: Novakovic Tatjana , Rozic Ljiljana , Vukovic Zorica , Petrovic Srdjan
Published: May 2011

Sintering and crystallization of low-density polyethylene glycol (PEG) and
lanthanum, La(III)-doped Al2O3 aerogels prepared from aluminum isopropoxide
were investigated. The sintering behavior of non-doped and doped aerogels was
examined by following the change of specific surface area with isothermal
heat-treatment. The specific surface area and crystalline phases of non-doped
and PEG+La(III)-doped aerogels were determined, and the effects of dopants on
the sintering and crystallization of Al2O3 aerogels are discussed. Isothermal
sintering experiments showed that the sintering mechanism of non-doped and
PEG+La(III)-doped Al2O3 aerogels is surface diffusion. The specific surface
areas of alumina samples decrease rapidly during the initial period of
sintering, and more slowly with prolonged sintering time. The change of the
porous structure is correlated with the phase transformation of ?-Al2O3
during calcinations of Al2O3 aerogels. The surface area of non-doped Al2O3
aerogels came to about 20 m2g-1 with heat-treatment at 1100?C because of
crystallization of ?-Al2O3 after densification. In the case of heattreatment
at 1200?C, the largest surface area was observed for PEG+La(III) doped Al2O3
aerogels and the XRD pattern showed only low ordered ?-Al2O3. These indicate
that the addition of PEG+La(III) to boehmite sol prevents Al2O3 aerogels from
sintering and crystallizing to the ?-Al2O3 phase. Even after 20 h at 1000?C,
PEG+La (III)-doped alumina samples maintain a rather good specific surface
area (108 m2 g-1) in comparison to the non-doped, containing mainly ?-Al2O3
and minor amounts of ?-Al2O3. Aluminum-oxides with these structural and
textural properties are widely used as a coatings and catalyst supports in
the field of various catalysis.
Transforming American Education
Authors: Horn Michael B. , Mackey Katherine
Published: May 2011

In this article the authors accept as a given the National Education Technology Plan's vision of a transformed education system powered by technology such that learners receive personalized and engaging learning experiences, and where assessment, teaching, infrastructure, and productivity are redefined. The article analyzes this vision of a transformed education system through the theories of disruptive innovation to ask how this vision might come to fruition. Through this process, it unearths a series of principles to guide action in implementing the vision.
Transforming American Education: Revolution or Counter-Revolution?
Authors: Waks Leonard J.
Published: May 2011

This article critiques the report of President Obama's taskforce on educational technology, ‘Transforming American Education’. It calls into question the claims of the authors that the proposed policy is ‘revolutionary’, and then offers a point-by-point comparison between the report's recommendations and those derived from a perspective taking full account of the genuinely revolutionary implications for learning of the new web 2.0 technologies. It concludes that the taskforce proposals constrain rather than facilitate the digital revolution in education.
The Development of Business Standardization and Integrated Management Systems
Authors: Majstorović Vidosav , Marinković Valentina
Published: May 2011

The Development of Business Standardization and Integrated Management Systems

At the beginning of the 21st century, business standardization has been experiencing intense development, while technical standardization has been moved to the background. Globalization, the development and application of IT technology, the global economic crisis and severe conditions in business have only contributed to this development. Today, the most current standards to be applied are ISO 9000, 14000, 17000, 18000, 20000, 22000, 27000, 31000 and others. At this point the basic question that arises is how to apply these standards in an integrated fashion. Integrated management systems are the answer, which should connect at least two standards or at best all of them - from five to seven. This paper deals with the development of individual models of business standardization, and their integration in the design and implementation of IMS, from the viewpoint of quality management requirements, environmental protection, the safety and health protection of employees and some other demands.
Blood Ferritin Levels in Pregnant Women and Prediction of the Development of Fetal Intrauterine Growth Restriction
Authors: Višnjevac Nemanja , Segedi Ljiljana , Ćurčić Aleksandar , Višnjevac Jovana , Stajić Dragan
Published: May 2011

Blood Ferritin Levels in Pregnant Women and Prediction of the Development of Fetal Intrauterine Growth Restriction

Intrauterine growth restriction is one of the leading causes of perinatal morbidity and mortality. Prediction of intrauterine growth restriction is one of the priority tasks of perinatal protection. The purpose of this study was to evaluate the levels of serum ferritin in pregnant women, which could point to a group of patients in whom possible development of fetal growth restriction could have been expected. In this investigation, we conducted a prospective study of healthy pregnant women between 30 and 32 gestational weeks, who were estimated for ferritin values. Newborn infants of low birth weight for gestational age were recorded in 8.1%. Anemia was not present in any of the patients who delivered low birth weight babies. Ferritin serum levels in mothers of the babies with low birth weight were on average 6.42 μg/L higher than in the mothers with appropriate for gestational age babies (p<0.005). ROC analysis of newborn infants birth weight and maternal blood ferritin levels showed that blood ferritin level had good predictive value. In case the recorded maternal blood ferritin values are above 13.6 μg/L, we can assume with the sensitivity of 64.7% and specificity of 91.7%, that the pregnant woman will develop a condition of intrauterine growth restriction. The missing decrease of ferritin values, erythrocytes, hemoglobin and hematocrit in the blood of healthy pregnant women between 30 and 32 gestational weeks, can with high probability point to the development of fetal intrauterine growth restriction.
Model of Enterpreneurship and Social-cultural and Market Orientation of Small Business Owners in Poland
Authors: Walczak-Duraj Danuta
Published: May 2011

The subject of considerations of the text are the dominant socio-cultural and market orientations of small business in Poland. These orientations are related to the four dominant models of entrepreneurship in Poland: disaster, evolutionary, system and ethical, while their analysis is performed for Tyree basic perspectives. Firstly, from the perspective of the basic functions that can perform these orientations in the development or slowing of the enterprises market. Secondly, from the perspective of the dynamics of technological change and accompanying uncertainties in the sphere of business. Thirdly, the spatial perspective: local, regional and global scales. In the development of SMEs in Poland crucial meaning is legislation, steadily adapted to EU regulations, especially to the European Charter for Small Enterprises. Research conducted in Poland by many authors provide data for doing so, to confirm the hypothesis that among small businesses a vital role in shaping their work situation did not continue to play the market mechanisms and orientations, but mainly socio-cultural factors.
Corporate Culture and Its Connection with External and Internal Public Relations
Authors: Kotras Marcin
Published: May 2011

The main aim of this article is to present the influence of corporate culture on company's stakeholders. This paper signalises the tendency in corporate communication with its internal and external publics. It is focused on two issues: corporate social responsibility and employer branding. Those two categories are consequences of corporate culture model.
Comparative Analysis of Private Equity Market in Poland and Other Central and Eastern European Countries
Authors: Sosnowski Tomasz
Published: May 2011

The main goal of this article is an analysis of the development stage attained by the private equity market in Poland and its comparison with similar markets in other countries of Central and Eastern Europe. The main emphasis has been laid on the very essence of this source of capital and its importance for development of small and medium-sized enterprises. The performed analysis has allowed to verity the hypothesis saying that private equity funds in Poland display a greater involvement in comparison with such funds in the remaining countries of this region, which is confirmed by the value of capital invested in Polish enterprises and the value of divestments in Poland. The empirical data used in this article come from statistical reports of the European Private Equity and Venture Capital Association.
Immunopathological Characteristics of Cryptoglandular and Crohn's Anorectal Fistulas
Authors: Hadzhiev Bozhidar , Murdjeva Mariana
Published: May 2011

Immunopathological Characteristics of Cryptoglandular and Crohn's Anorectal Fistulas

Anorectal fistulas are quite common proctologic disorders. They can be either of cryptoglandular origin or can be associated with Crohn's disease and chronic ileocolitis. Mechanical obstruction and local infections are prime causes of this pathological condition. Genetic predisposition and inadequate immune response with overproduction of pro-inflammatory cytokines appear prominently in the course of Crohn's disease. Interferon-γ, a Th1 type cytokine, reflecting the engagement of cellular immune mechanisms, is the first to be produced in the intestinal mucosa. The inflammatory process in the colon mucosa induced by the abundant microbial flora is sustained and turned chronic by the gradual elevation of the local TNF-α and regulatory cytokines levels (interleukin-10, transforming growth factor-β). The number of activated local memory T cells CD4+CD45RBloincreases significantly. The regulatory CD4+CD25+ T lymphocytes producing interleukin-10 increase also trying to counterbalance the cytokine reaction. The chronic inflammatory infiltrates of the colon mucosa are represented by lymphocytes, plasma cells, macrophages. The long-term activation of macrophages by the released interferon-γ leads to tissue damage and potentiation of angiogenesis - a risk factor for carcinoma development. Management of anorectal abscesses and fistulas is complex aiming to alleviate the symptoms, prevent relapses, reduce the risk of sphincter damage and improve quality of life. The main approach (surgery) should be combined with antimicrobial infection control and immunomodulation by intravenous or local administration of anti-TNF-α antibodies.
3D-QSAR Studies on a Series of Dihydroorotate Dehydrogenase Inhibitors: Analogues of the Active Metabolite of Leflunomide
Authors: Li Shun-Lai , He Mao-Yu , Du Hong-Guang
Published: May 2011

The active metabolite of the novel immunosuppressive agent leflunomide has been shown to inhibit the enzyme dihydroorotate dehydrogenase (DHODH). This enzyme catalyzes the fourth step in de novo pyrimidine biosynthesis. Self-organizing molecular field analysis (SOMFA), a simple three-dimensional quantitative structure-activity relationship (3D-QSAR) method is used to study the correlation between the molecular properties and the biological activities of a series of analogues of the active metabolite. The statistical results, cross-validated rCV2 (0.664) and non cross-validated r2 (0.687), show a good predictive ability. The final SOMFA model provides a better understanding of DHODH inhibitor-enzyme interactions, and may be useful for further modification and improvement of inhibitors of this important enzyme.
Neuroprotective Effects of Marine Algae
Authors: Pangestuti Ratih , Kim Se-Kwon
Published: May 2011

The marine environment is known as a rich source of chemical structures with numerous beneficial health effects. Among marine organisms, marine algae have been identified as an under-exploited plant resource, although they have long been recognized as valuable sources of structurally diverse bioactive compounds. Presently, several lines of studies have provided insight into biological activities and neuroprotective effects of marine algae including antioxidant, anti-neuroinflammatory, cholinesterase inhibitory activity and the inhibition of neuronal death. Hence, marine algae have great potential to be used for neuroprotection as part of pharmaceuticals, nutraceuticals and functional foods. This contribution presents an overview of marine algal neuroprotective effects and their potential application in neuroprotection.
Docosahexaenoic Acid (DHA): An Ancient Nutrient for the Modern Human Brain
Authors: Bradbury Joanne
Published: May 2011

Modern humans have evolved with a staple source of preformed docosahexaenoic acid (DHA) in the diet. An important turning point in human evolution was the discovery of high-quality, easily digested nutrients from coastal seafood and inland freshwater sources. Multi-generational exploitation of seafood by shore-based dwellers coincided with the rapid expansion of grey matter in the cerebral cortex, which characterizes the modern human brain. The DHA molecule has unique structural properties that appear to provide optimal conditions for a wide range of cell membrane functions. This has particular implications for grey matter, which is membrane-rich tissue. An important metabolic role for DHA has recently been identified as the precursor for resolvins and protectins. The rudimentary source of DHA is marine algae; therefore it is found concentrated in fish and marine oils. Unlike the photosynthetic cells in algae and higher plants, mammalian cells lack the specific enzymes required for the de novo synthesis of alpha-linolenic acid (ALA), the precursor for all omega-3 fatty acid syntheses. Endogenous synthesis of DHA from ALA in humans is much lower and more limited than previously assumed. The excessive consumption of omega-6 fatty acids in the modern Western diet further displaces DHA from membrane phospholipids. An emerging body of research is exploring a unique role for DHA in neurodevelopment and the prevention of neuropsychiatric and neurodegenerative disorders. DHA is increasingly being added back into the food supply as fish oil or algal oil supplementation.
Dehydration Influences Mood and Cognition: A Plausible Hypothesis?
Authors: Benton David
Published: May 2011

The hypothesis was considered that a low fluid intake disrupts cognition and mood. Most research has been carried out on young fit adults, who typically have exercised, often in heat. The results of these studies are inconsistent, preventing any conclusion. Even if the findings had been consistent, confounding variables such as fatigue and increased temperature make it unwise to extrapolate these findings. Thus in young adults there is little evidence that under normal living conditions dehydration disrupts cognition, although this may simply reflect a lack of relevant evidence. There remains the possibility that particular populations are at high risk of dehydration. It is known that renal function declines in many older individuals and thirst mechanisms become less effective. Although there are a few reports that more dehydrated older adults perform cognitive tasks less well, the body of information is limited and there have been little attempt to improve functioning by increasing hydration status. Although children are another potentially vulnerable group that have also been subject to little study, they are the group that has produced the only consistent findings in this area. Four intervention studies have found improved performance in children aged 7 to 9 years. In these studies children, eating and drinking as normal, have been tested on occasions when they have and not have consumed a drink. After a drink both memory and attention have been found to be improved.
A Meta Analysis on Farm-Level Costs and Benefits of GM Crops
Authors: Finger Robert , El Benni Nadja , Kaphengst Timo , Evans Clive , Herbert Sophie , Lehmann Bernard , Morse Stephen , Stupak Nataliya
Published: May 2011

This paper reviews the evidence on the socio-economic impacts of GM crops and analyzes whether there are patterns across space and time. To this end, we investigate the effect of GM crops on farm-level costs and benefits using global data from more than one decade of field trials and surveys. More specifically, we analyze the effects of GM-crops on crop yields, seed costs, pesticide costs, and management and labor costs and finally gross margins. Based on collected data from studies on Bt cotton and Bt maize, statistical analyses are conducted to estimate the effect of GM crop adoption on these parameters. Our results show that, compared to conventional crops, GM crops can lead to yield increases and can lead to reductions in the costs of pesticide application, whereas seed costs are usually substantially higher. Thus, the results presented here do support the contention that the adoption of GM crops leads on average to a higher economic performance, which is also underlined by the high adoption rates for GM crops in a number of countries. However, the kind and magnitude of benefits from GM crops are very heterogeneous between countries and regions, particularly due to differences in pest pressure and pest management practices. Countries with poor pest management practices benefited most from a reduction in yield losses, whereas other countries benefited from cost reductions. However, our study also reveals limitations for meta-analyses on farm-level costs and benefits of GM crops. In particular, published data are skewed towards some countries and the employed individual studies rely on different assumptions, purposes and methodologies (e.g., surveys and field trials). Furthermore, a summary of several (often) short-term individual studies may not necessarily capture long-term effects of GM crop adoption.
CALCULATING THE CARRYING CAPACITY OF FLEXURAL PRESTRESSED CONCRETE BEAMS WITH NON-METALLIC REINFORCEMENT
Authors: Atutis Mantas
Published: May 2011

The article reviews moment resistance design methods of prestressed concrete beams with fibre-reinforced polymer (FRP) reinforcement. FRP tendons exhibit linear elastic response to rupture without yielding and thus failure is expected to be brittle. The structural behaviour of beams prestressed with FRP tendons is different from beams with traditional steel reinforcement. Depending on the reinforcement ratio, the flexural behaviour of the beam can be divided into several groups. The numerical results show that depending on the nature of the element failure, moment resistance calculation results are different by using reviewed methods. It was found, that the use of non-metallic reinforcement in prestressed concrete structures is effective: moment capacity is about 5% higher than that of the beams with conventional steel reinforcement.
DESIGNING A PHYSICAL MODEL FOR THE INTERACTION BETWEEN DISPLACEMENT PILES AND SOIL
Authors: Jankauskas Arūnas , Gadeikytė Sonata
Published: May 2011

The article deals with the interaction between piles installed in dusty sandy clay and the base. The paper reviews experimental and theoretical work, presents a geological litological structure of soil and looks at the methods of composing a model. The article also describes the model of the carried out experiment and analyzes directions towards soil movement. Field and laboratory studies as well as soil analysis, including its distribution scheme are provided. Ground elevation around the piles has been calculated. A new physical model has been created on the basis of the before examined physical model and its reasoning.
THE IMPACT OF MAGNESIUM OXIDE ON THE HYDRATATION AND FEATURES OF MECHANICALY ACTIVATED PHOSPHOGYPSUM
Authors: Jefimovas Andrejus
Published: May 2011

Extractive hemihydrate phosphogypsum (E-PG) is the most popular mineral waste in Lithuania. The dumps of that are rapidly growing and the question of possible use still remains open. Phosphogypsum is obtained during the process of extracting phosphoric acid from apatite using sulphuric acid. Due to low activity and contamination with acidic mineral admixtures (phosphorus and fluorine compounds), this technogenic product cannot be used for producing construction materials. Instead of present energy consuming processes used for neutralisation, another method – mechanical activation neutralizing acid admixtures with cement and opoka mix is offered. Whereas cement and opoka are grey, the items made of phosphogypsum (neutralised using these admixtures) are dark. Research was made trying to find out the possibility of gaining the white binder from phosphogypsum. In order to achieve that magnesium oxide was chosen to neutralise phosphogypsum and its impact on E-PG, hydratation and features were studied.
ANALYSIS OF THE INFLUENCE OF THE MODERNIZED BITUMEN BATCHING SYSTEM ON THE COMPOSITION OF THE HOT MIX ASPHALT MIXTURE
Authors: Bražiūnas Justas , Sivilevičius Henrikas
Published: May 2011

The weighted mass of a binder in the bucket of the bitumen batcher of a batch-type asphalt plant should be such that its percentage of hot mix asphalt (HMA) mixture lot would comply with the design amount of the job-mix formula in all mix batches. A bitumen batcher does not always weigh bitumen portions precisely. Their mass deviations from the amount determined by the project and its variation impair HMA composition and performance. The paper provides data on a statistical evaluation of bitumen batcher modernization performed at Lithuanian enterprise „LL“. The article analyzes differences in the structures of reconstructed and not reconstructed bitumen batching systems and presents methods for determining modernization effectiveness. The paper also focuses on the effectiveness of the batching system, determining deviations from bitumen content in subsamples taken and extracted everyday during two seasons (before and after batcher‘s modernization) of producing HMA from the value of job-mix formula and comparing them to the values of tolerances.
MODERN TRANSPORT MANAGEMENT TECHNOLOGIES. TRANSPORTATION OPTIMIZATION
Authors: Ugnenko Julija , Ugnenko Julija , Mazor Tatjana
Published: May 2011

The article considers the theoretical aspects of modern transport management technologies and transport optimization. The paper demonstrates that the quantitative characteristics of transportation should be used for establishing an optimum criterion for making decisions on route optimization.
MODELLING TRAFFIC FLOWS USING GRAPH THEORY
Authors: Musyt Oksana , Nadtochij Oksana , Stepanchiuk Aleksandr , Beljatynskij Andrej
Published: May 2011

An intensive increase in road transport, particularly individual, in recent years has led to such consequences as increased time spent on travel, the number of forced stops, traffic accidents, the occurrence of traffic jams on the road network, reducing traffic speed and a deteriorated urban road network in cities. The most effective method for solving these problems is the use of graph theory, the main characteristics of which is reliability, durability and accessibility of a free as well as loaded network. Based on their analysis the methods for network optimization are proposed.
MODELING RECYCLING ASPHALT PAVEMENT PROCESSING TECHNOLOGIES IN ASPHALT MIXING PLANTS
Authors: Tamaliūnas Simonas , Sivilevičius Henrikas
Published: May 2011

The article presents reclaimed asphalt pavement (RAP) processing technologies and equipment models used in the asphalt mixing plant (AMP). The schematic model indicating all possible ways to process RAP in AMP is shown. The model calculating the needed temperature of mineral materials used for heating RAP is given and an example of such calculation is provided.
REORGANIZATION OF LITHUANIAN AIRSPACE
Authors: Kondroška Vaidotas , Stankūnas Jonas
Published: May 2011

The basic purpose of the article is considering problems related to ensuring the required capacity of Lithuanian airspace and organising the provision of air traffic services in the most efficient way. The paper presents the results of analysis and experimental research on several scenarios of Lithuanian airspace models that are the most appropriate from the point of view of air traffic control. To allow for a realistic comparison between the scenarios and traffic samples, the current route network, a real traffic sample and the existing traffic dynamics have been used. Furthermore, all other related aspects such as flight level occupancy, flight time, aircraft type and traffic flows have been taken into consideration. The results of analysis will form a basis for ensuring the required capacity of Lithuanian airspace.
Equinodermos del Cámbrico de España: situación actual de las investigaciones y perspectivas futuras
Authors: Zamora S.
Published: May 2011

En este trabajo se presenta una revisión histórica de todos los equinodermos cámbricos descubier tos en España, desde su primer hallazgo a finales del siglo XIX y las técnicas actuales que se utilizan para su estudio.

El muestreo sistemático de nuevas localidades cámbricas del Norte de España y la revisión de otras ya conocidas, ha proporcionado más de 2.000 ejemplares de equinodermos. En total se han reconocido taxones pertenecientes a cinco clases: Cincta, Eocrinoidea, Edrioasteroidea, Stylophora y Ctenocystoidea, que muestran la mayor diversidad para este periodo en Gondwana.

Estos hallazgos muestran que los equinodermos alcanzaron su primer pico de diversidad durante el Cámbrico medio. Esto, unido a la amplia distribución paleobiogeográfica de algunos clados, nos advierte de un origen para muchos grupos en el Cámbrico inferior, donde sólo unos pocos taxones han sido descritos a nivel mundial. Por último se dan algunas ideas de hacia dónde se podrían dirigir los esfuerzos en este campo de conocimiento.
Amylase, maltase and sucrase activities in hepatopancreas of the euryhaline crab Neohelice granulata (Decapoda: Brachyura: Varunidae): partial characterization and response to low environmental salinity
Authors: Asaro Antonela , Del Valle Juana Cristina , López Mañanes Alejandra Antonia
Published: May 2011

Studies on digestive adjustments at the biochemical level in relation to salinity in euryhaline crabs are lacking. Moreover, knowledge of biochemical digestive characteristics of euryhaline crabs (i.e. occurrence and characteristics of key digestive enzyme activities) is still scarce and fragmentary. We studied the occurrence, characteristics and response to low salinity of amylase, maltase and sucrase activities in the hepatopancreas of the euryhaline crab Neohelice (Chasmagnathus) granulata. Maximal amylase and maltase activities were found at pH 5.2. Sucrase activity was maximal within the pH range 3.6-5.2. Amylase, maltase and sucrase activities showed a Michaelis-Menten kinetics (km = 0.41±0.10 mg ml-1; 1.37±1.03 mM and 0.55±0.45 mM, respectively). In crabs acclimated to low salinity (10 psu; hyperregulating conditions), amylase activity (7263±980 μg maltose min-1 mg prot-1) was higher than in 35 psu (osmoconforming conditions) (3605±340 μg maltose min-1 mg prot-1). Maltase and sucrase activities (497±98 and 64±16 μg glucose min-1 mg prot-1, respectively) were similar in both salinities. The response of amylase activity to low salinity suggests a role in digestive adjustments upon hyperregulation. This study contributes to a better understanding of the complexity of the biochemical adaptations to low salinity in euryhaline crabs.
A new squat lobster of the genus Munidopsis (Crustacea: Decapoda: Munidopsidae) from the Mediterranean Sea
Authors: Macpherson Enrique
Published: May 2011

A new species of Munidopsis Whiteaves, 1874 is reported from the south of Crete, at 2046-2104 m, in the eastern Mediterranean Sea. The species (M. ariadne) is morphologically closely related to M. maunga Schnabel and Bruce, 2006, from New Zealand. The species is also close to M. polymorpha Koelbel, 1892, from Lanzarote, Canary Islands, and M. talismani A. Milne Edwards and Bouvier, 1894, from the NW Africa. The new species is described and illustrated and a diagnosis along with full illustration is provided for the latter 2 species.
Murine Guanylate Cyclase C Regulates Colonic Injury and Inflammation
Authors: Steinbrecher Kris A. , Harmel-Laws Eleana , Garin-Laflam Monica P. , Mann Elizabeth A. , Bezerra Lucas D. , Hogan Simon P. , Cohen Mitchell B.
Published: May 2011

Guanylate cyclase C (GUCY2C or GC-C) and its ligands, guanylin (GUCA2A or Gn) and uroguanylin (GUCA2B or Ugn), are expressed in intestinal epithelial cells and regulate ion secretion, intestinal barrier function, and epithelial monolayer homeostasis via cGMP-dependent signaling pathways. The aim of this study was to determine whether GC-C and its ligands direct the course of intestinal inflammation. In this article, we show that dextran sodium sulfate (DSS)-induced clinical disease and histological damage to the colonic mucosa were significantly less severe in GC-C−/− mice and moderately reduced in Gn−/− animals. Relative to wild-type controls, GC-C−/− and Gn−/− mice had reduced apoptosis and increased proliferation of intestinal epithelial cells during DSS colitis. Basal and DSS-induced production of resistin-like molecule β (RELMβ) was substantially diminished in GC-C−/− mice. RELMβ is thought to stimulate cytokine production in macrophages in this disease model and, consistent with this, TNF-α and IFN-γ production was minimal in GC-C−/− animals. RELMβ and cytokine levels were similar to wild-type in Gn−/− mice, however. Colonic instillation of recombinant RELMβ by enema into GC-C−/− mice restores sensitivity to DSS-mediated mucosal injury. These findings demonstrate a novel role for GC-C signaling in facilitating mucosal wounding and inflammation, and further suggest that this may be mediated, in part, through control of RELMβ production.
Large TCR Diversity of Virus-Specific CD8 T Cells Provides the Mechanistic Basis for Massive TCR Renewal after Antigen Exposure
Authors: Miconnet Isabelle , Marrau Angélique , Farina Alex , Taffé Patrick , Vigano Selena , Harari Alexandre , Pantaleo Giuseppe
Published: May 2011

Ex vivo analysis of virus-specific CD8 T cell populations by anchored PCR has shown that the CD8 TCR repertoire was less oligoclonal (seven to nine clonotypes per individual epitope) than previously thought. In the current study, TCR diversity was investigated by assessing both the overall TCR β-chain variable regions usage as well as the CDR3 regions in ex vivo-isolated CMV- and EBV-specific CD8 T cells from 27 healthy donors. The average number of clonotypes specific to most single viral epitopes comprised between 14 and 77. Changes in the CD8 TCR repertoire were also longitudinally assessed under conditions of HIV-1 chronic infection (i.e., in patients with suppressed virus replication and after treatment interruption and Ag re-exposure). The results showed that a large renewal (≤80%) of the TRB repertoire occurred after Ag re-exposure and was eventually associated with an increased T cell recognition functional avidity. These results demonstrate that the global CD8 TCR repertoire is much more diverse (≤9-fold) than previously estimated and provide the mechanistic basis for supporting massive repertoire renewal during chronic virus infection and Ag re-exposure.
Tumor Cell Programmed Death Ligand 1-Mediated T Cell Suppression Is Overcome by Coexpression of CD80
Authors: Haile Samuel T. , Bosch Jacobus J. , Agu Nnenna I. , Zeender Annette M. , Somasundaram Preethi , Srivastava Minu K. , Britting Sabine , Wolf Julie B. , Ksander Bruce R. , Ostrand-Rosenberg Suzanne
Published: May 2011

Programmed death ligand 1 (PDL1, or B7-H1) is expressed constitutively or is induced by IFN-γ on the cell surface of most human cancer cells and acts as a “molecular shield” by protecting tumor cells from T cell-mediated destruction. Using seven cell lines representing four histologically distinct solid tumors (lung adenocarcinoma, mammary carcinoma, cutaneous melanoma, and uveal melanoma), we demonstrate that transfection of human tumor cells with the gene encoding the costimulatory molecule CD80 prevents PDL1-mediated immune suppression by tumor cells and restores T cell activation. Mechanistically, CD80 mediates its effects through its extracellular domain, which blocks the cell surface expression of PDL1 but does not prevent intracellular expression of PDL1 protein. These studies demonstrate a new role for CD80 in facilitating antitumor immunity and suggest new therapeutic avenues for preventing tumor cell PDL1-induced immune suppression.
Lung Neutrophils Facilitate Activation of Naive Antigen-Specific CD4+ T Cells during Mycobacterium tuberculosis Infection
Authors: Blomgran Robert , Ernst Joel D.
Published: May 2011

Initiation of the adaptive immune response to Mycobacterium tuberculosis occurs in the lung-draining mediastinal lymph node and requires transport of M. tuberculosis by migratory dendritic cells (DCs) to the local lymph node. The previously published observations that 1) neutrophils are a transiently prominent population of M. tuberculosis-infected cells in the lungs early in infection and 2) that the peak of infected neutrophils immediately precedes the peak of infected DCs in the lungs prompted us to characterize the role of neutrophils in the initiation of adaptive immune responses to M. tuberculosis. We found that, although depletion of neutrophils in vivo increased the frequency of M. tuberculosis-infected DCs in the lungs, it decreased trafficking of DCs to the mediastinal lymph node. This resulted in delayed activation (CD69 expression) and proliferation of naive M. tuberculosis Ag85B-specific CD4 T cells in the mediastinal lymph node. To further characterize the role of neutrophils in DC migration, we used a Transwell chemotaxis system and found that DCs that were directly infected by M. tuberculosis migrated poorly in response to CCL19, an agonist for the chemokine receptor CCR7. In contrast, DCs that had acquired M. tuberculosis through uptake of infected neutrophils exhibited unimpaired migration. These results revealed a mechanism wherein neutrophils promote adaptive immune responses to M. tuberculosis by delivering M. tuberculosis to DCs in a form that makes DCs more effective initiators of naive CD4 T cell activation. These observations provide insight into a mechanism for neutrophils to facilitate initiation of adaptive immune responses in tuberculosis.
Predictors of Clients' Satisfaction with Delivery of Animal Health Care Services in Periurban Ghana
Authors: Turkson Paa Kobina
Published: May 2011

The study used logistic regression modelling to determine predictors of satisfaction with delivery of animal health care services for 889 clients (livestock and poultry keepers) in periurban Ghana. Of the 15 indicators tested as predictors of satisfaction in this study, 8 were included in the best fit model. These were accessibility, availability of services, service charge, effectiveness, efficiency, quality of services, meeting client needs, and getting help. Efficiency and effectiveness were perceived by the respondents to be synonymous, as were service quality and effectiveness, as suggested by when cross tabulated. Therefore, one or the other could be used in future studies but not both to avoid collinearity. The identified predictors could be targeted for improvement in quality of service delivery to livestock and poultry keepers in Ghana.
MicroRNA Role in Thyroid Cancer Development
Authors: Marini Francesca , Luzi Ettore , Brandi Maria Luisa
Published: May 2011

MicroRNAs (miRNAs) are endogenous noncoding RNAs that negatively regulate gene expression by binding the 3′noncoding region of the messenger RNA targets inducing their cleavage or blocking the protein translation. They play important roles in multiple biological and metabolic processes, including developmental timing, signal transduction, and cell maintenance and differentiation. Their deregulation can predispose to diseases and cancer. miRNA expression has been demonstrated to be deregulated in many types of human tumors, including thyroid cancers, and could be responsible for tumor initiation and progression. In this paper we reviewed the available data on miRNA deregulation in different thyroid tumors and describe the putative role of miRNA in thyroid cancer development.
A Review of Carcinomas Arising in the Head and Neck Region in HIV-Positive Patients
Authors: Purgina Bibianna , Pantanowitz Liron , Seethala Raja R.
Published: May 2011

The majority of malignancies arising in the head and neck among patients with AIDS are Kaposi sarcoma and non-Hodgkin lymphoma. Patients with HIV/AIDS are also at increased risk of developing several carcinomas of the head and neck. This paper focuses on these less common, albeit important, carcinomas. An English language literature search identified numerous population-based studies evaluating carcinomas in the head and neck of HIV-positive patients. Published results indicate that patients with HIV/AIDS are at an increased risk of developing mucosal squamous cell carcinoma, nasopharyngeal carcinoma, lymphoepithelial carcinoma of the salivary gland, and Merkel cell carcinoma in this anatomic region. Data also suggest that HIV-positive patients with these cancers present at a younger age, with more aggressive disease and worse prognosis compared to HIV-negative patients. Treatment involves surgical resection with or without radiation therapy and chemotherapy for locally advanced and metastatic disease. AIDS patients, however, are more likely to suffer radiation treatment complications. Highly active antiretroviral therapy (HAART) has not altered the incidence of these malignancies.
The Adaptive Radiation of Cichlid Fish in Lake Tanganyika: A Morphological Perspective
Authors: Takahashi Tetsumi , Koblmüller Stephan
Published: May 2011

Lake Tanganyika is the oldest of the Great Ancient Lakes in the East Africa. This lake harbours about 250 species of cichlid fish, which are highly diverse in terms of morphology, behaviour, and ecology. Lake Tanganyika's cichlid diversity has evolved through explosive speciation and is treated as a textbook example of adaptive radiation, the rapid differentiation of a single ancestor into an array of species that differ in traits used to exploit their environments and resources. To elucidate the processes and mechanisms underlying the rapid speciation and adaptive radiation of Lake Tanganyika's cichlid species assemblage it is important to integrate evidence from several lines of research. Great efforts have been, are, and certainly will be taken to solve the mystery of how so many cichlid species evolved in so little time. In the present review, we summarize morphological studies that relate to the adaptive radiation of Lake Tanganyika's cichlids and highlight their importance for understanding the process of adaptive radiation.
Ovarian Follicular Dynamics during the Estrous Cycle in Jennies in Upper Egypt
Authors: Derar R. I. , Hussein H. A.
Published: May 2011

The objective of the current study was to describe follicular dynamics in Egyptian Jennies throughout the estrous cycle. In this experiment, 8 estrus cycles in 8 cyclic Jennies were studied from February to June using ultrasonography. The result revealed that one follicular wave per cycle was recorded throughout the studied period. Dominant follicle (DF) was firstly detected at day in Jennies. The growth rate of DF was  mm/day. Left ovulations were nonsignificantly () more than right ovulations (55.6% versus 44.6%). The CL was firstly detected at D , developed in a rate of  mm/day, reached a maximum diameter of  mm at D , and started to regress on D with a mean regression rate of  mm d-1. Results of the present study indicated that Jennies had one follicular wave per cycle. The Day of the cycle has a significant effect on the number of different classes of the ovarian follicles, but not large ones. Ultrasonographic characteristics of the preovulatory follicles could be useful to predict ovulation. CL developed and regressed in a slow rate.
How Age Affects Auditory-Cognitive Interactions in Speech Comprehension
Authors: Schneider B.A.
Published: May 2011

To participate effectively in multi-talker conversations, listeners need to do more than simply recognize and repeat speech. They have to keep track of who said what, extract the meaning of each utterance, store it in memory for future use, integrate the incoming information with what each conversational participant has said in the past, and draw on the listener’s own knowledge of the topic under consideration to extract general themes and formulate responses. In other words, to acquire and use the information contained in spoken language requires the smooth and rapid functioning of an integrated system of perceptual and cognitive processes. Here we review evidence indicating that the operation of this integrated system of perceptual and cognitive processes is more easily disrupted in older than in younger adults, especially when there are competing sounds in the auditory scene.
Age-Related Changes in Auditory and Cognitive Abilities in Elderly Persons with Hearing Aids Fitted at the Initial Stages of Hearing Loss
Authors: Obuchi C. , Harashima T. , Shiroma M.
Published: May 2011

In this study, we investigated the relation between the use of hearing aids at the initial stages of hearing loss and age-related changes in the auditory and cognitive abilities of elderly persons. 12 healthy elderly persons participated in an annual auditory and cognitive longitudinal examination for three years. According to their hearing level, they were divided into 3 subgroups - the normal hearing group, the hearing loss without hearing aids group, and the hearing loss with hearing aids group. All the subjects underwent 4 tests: pure-tone audiometry, syllable intelligibility test, dichotic listening test (DLT), and Wechsler Adult Intelligence Scale-Revised (WAIS-R) Short Forms. Comparison between the 3 groups revealed that the hearing loss without hearing aids group showed the lowest scores for the performance tasks, in contrast to the hearing level and intelligibility results. The other groups showed no significant difference in the WAIS-R subtests. This result indicates that prescription of a hearing aid during the early stages of hearing loss is related to the retention of cognitive abilities in such elderly people. However, there were no statistical significant correlations between the auditory and cognitive tasks.
Hearing Impairment in Dementia – How to Reconcile Two Intertwined Challenges in Diagnostic Screening
Authors: Lemke U.
Published: May 2011

Prevalence of dementia as well as hearing impairment is increasing with age[...]
Pilot Initiatives of Adult Hearing Screening in Italy
Authors: Paglialonga A. , Tognola G. , Grandori F.
Published: May 2011

A series of pilot initiatives of adult hearing screening programs were organized in eight large and small-size cities in Italy in the past two years. The screening initiatives were held in public places, supermarkets, drugstores, and in some universities of the third age, and involved an overall population of 2,278 screened subjects with age ranging from 13 to 93 years. Three different screening tests were used to assess hearing ability in the participants, i.e.: screening pure tone audiometry (PTA), an automated speech-in-noise screening test (the SUN-test), and a screening questionnaire of self-perceived hearing handicap (the HHIE-S). This paper describes the organization and management of these screening initiatives and reviews the main results obtained in the screened population, using the three different screening tests. Results obtained in these pilot initiatives showed that screening adults for hearing problems might be feasible, on a local level, in non clinical settings and can be performed quite easily with the support of local coordinators and partners, such as associations or local authorities. It is recognized that further initiatives and studies will have to be performed to better define the key aspects related to the organization and management of adult hearing screening programs, either at a local, regional, or national level.