bluuebunny/crossref_metadata_2025 huggingface dataset:
Intelligent Robot Navigation using View Sequences and a Sparse Distributed Memory
Authors: Mendes Mateus , Coimbra A. Paulo , Crisóstomo Manuel M.
Published: April 2011

Different approaches have been tried to navigate robots, including those based on visual memories. The Sparse Distributed Memory (SDM) is a kind of associative memory based on the properties of high dimensional binary spaces. It exhibits characteristics such as tolerance to noise and incomplete data, ability to work with sequences and the possibility of one-shot learning. Those characteristics make it appealing to use for robot navigation. The approach presented in this work was to navigate a robot using sequences of visual memories stored into a SDM. The robot makes intelligent decisions, such as selecting only relevant images to store during path learning, adjusting memory parameters to the level of noise and inferring new paths from learnt trajectories. The method of encoding the information may influence the tolerance of the SDM to noise and saturation. The present paper reports novel results of the limits of the model under different typical navigation problems. An algorithm to build a topological map of the environment based on the visual memories is also described.
Multifractal properties of large bubble paths in a single bubble column
Authors: Mosdorf Romuald , Wyszkowski Tomasz , Dąbrowski Kamil
Published: April 2011

Multifractal properties of large bubble paths in a single bubble column

In the paper the paths of bubbles emitted from the brass nozzle with inner diameter equal to 1.6 mm have been analyzed. The mean frequency of bubble departure was in the range from 2 to 65.1 Hz. Bubble paths have been recorded using a high speed camera. The image analysis technique has been used to obtain the bubble paths for different mean frequencies of bubble departures. The multifractal analysis (WTMM - wavelet transform modulus maxima methodology) has been used to investigate the properties of bubble paths. It has been shown that bubble paths are the multifractals and the influence of previously departing bubbles on bubble trajectory is significant for bubble departure frequencyfb> 30 Hz.
On the Reynolds transport theorem for three phase systems with storage in interfaces
Authors: Skiepko Teodor
Published: April 2011

On the Reynolds transport theorem for three phase systems with storage in interfaces

In the paper, the Reynolds transport theorem (RTT) for three phase systems is developed, in terms associated with a moving control volume. The basic tools applied to the derivation are the generalized transport theorem by Truesdell and Toupin, and generalized surface transport theorem by Aris as well as Slattery. The final results referenced to a generic extensive quantity demonstrate the theorem in the integral instantaneous form. As a further illustration of applicability of the theorem relation developed some specific forms are deduced from such as for multiphase systems in terms of fixed control volume, surface systems and homogeneous spatial systems.
Analysis of cyclic combustion of the coal-water suspension
Authors: Kijo-Kleczkowska Agnieszka
Published: April 2011

Analysis of cyclic combustion of the coal-water suspension

Combustion technology of the coal-water suspension creates a number of new possibilities to organize the combustion process fulfilling contemporary requirements, e.g. in the environment protection. Therefore the in-depth analysis is necessary to examine the technical application of coal as a fuel in the form of suspension. The research undertakes the complex investigations of the continuous coal-water suspension as well as cyclic combustion. The cyclic nature of fuel combustion results from the movement of the loose material in the flow contour of the circulating fluidized bed (CFB): combustion chamber, cyclone and downcomer. The experimental results proved that the cyclic change of oxygen concentration around fuel, led to the vital change of both combustion mechanisms and combustion kinetics. The mathematical model of the process of fuel combustion has been presented. Its original concept is based on the allowance for cyclic changes of concentrations of oxygen around the fuel. It enables the prognosis for change of the surface and the centre temperatures as well as mass loss of the fuel during combustion in air, in the fluidized bed and during the cyclic combustion.
Surveillance and Sacrifice
Authors: Griffin Kimberly A. , Reddick Richard J.
Published: April 2011

Previous research documents Black professors’ heavy service commitments and time spent mentoring; yet little work explores how this form of faculty work differs by gender. This intersectional analysis examines narratives of 37 Black professors at three institutions (collected across two studies), focusing on how race and gender shape Black professors’ expectations and experiences mentoring. Findings indicate that racism and sexism influence whether and how Black faculty members mentor in unique ways. Women engage in close, personal relationships and face high gender-based expectations regarding student contact, leading to their carriage of a heavy mentoring burden. Men are more formal and compartmentalize their relationships, partly due to perceived visibility and surveillance, as well as increased likelihood of accusations of inappropriate relationships with female students.
From GED to College
Authors: Maralani Vida
Published: April 2011

Age patterns of secondary certification and college entry differ in complex and surprising ways for traditional graduates and GED recipients. Although GED recipients are less likely to enter college in their late teens, they catch up to traditional graduates in their 20s. Results show that adjusting for differences in the age trajectories of school continuation accounts for a substantial portion of the differences observed between the two groups. Important differences remain, however, in the type of college attended and the likelihood of college entry before age 21. Nonetheless, more GED recipients enroll in college than previous studies have suggested, and this interest in college identifies a useful place for policy to intervene to encourage school continuation for this group.
The effects of tool rotation speed and traverse speed on friction stir welding of AISI 304 austenitic stainless steel
Authors: Meran Cemal , Ersel Canyurt Olcay
Published: April 2011

In this study, AISI 304 (X5CrNi18-10, material identification number 1.4301) austenitic stainless steels, 3.0 mm thick, were joined by friction stir welding by applying different tool rotation speeds and traverse speeds, compressive forces and tool angles. The strength of the welded joints was improved by selecting suitable welding parameters. The maximum notch impact toughness was achieved on samples produced with 950 rpm rotation speed, 60 mm min−1 traverse speed, 9 kN compressive force, and 1.5° tool tilt angle. The maximum tensile strength of the weld zone was obtained on samples welded with 47.5 mm min−1 traverse speed, a rotational speed of 750 rpm, compressive force of 9 kN and tool tilt angle of 1.5°. The traverse speed of 47.5 mm min−1 was found to optimize the results of tensile strength and impact tests. Fine-grained microstructures occurred in the welded area. The weld joints obtained with friction stir welding have lower tensile strength compared to that of the base material. The experimental results indicate that AISI 304 austenitic stainless steels can be successfully joined considering both the strength of the welded joint and the appearance of the welding bead by selecting proper tool material and welding parameters using friction stir welding.
Finnis–Sinclair potentials for fcc Au–Pd and Ag–Pt alloys
Authors: Yan Xue-song , Lin Ping , Qi Xin , Yang Lei
Published: April 2011

The thermal and mechanical properties of Au, Pd, Ag, Pt pure metals and their alloys Au–Pd and Ag–Pt are studied using molecular dynamics simulations. The Finnis–Sinclair potential is used to describe the atomic interactions. Lattice constants and elastic constants of Au3Pd, AuPd, AuPd3, Ag3Pt, AgPt and AgPt3 at different temperatures are predicted for the first time. The melting temperatures of these alloys are also calculated. Furthermore, the values of lattice constants, elastic constants and melting temperatures of pure metals Au, Pd, Ag, and Pt are calculated for comparison. By comparing the simulation results of pure metals and alloys, it is found that for Au3Pd, AuPd, AuPd3 and Ag3Pt, lattice constants, elastic constants and melting temperatures lie between those of their components. For AgPt and AgPt3, the values of shear modulus C44 and melting temperatures are higher than those for both Ag and Pt pure metals.
Hollow pyramidal lattice truss structures
Authors: Queheillalt Douglas T. , Wadley Haydn N. G.
Published: April 2011

Pyramidal lattice core sandwich structures with millimeter scale hollow trusses have been assembled from 304 stainless steel tubes and bilayer face sheets, and bonded using a vacuum brazing approach. Rigid, large interfacial area nodes between the trusses and face sheets could be made by this approach. The through-thickness compression and transverse shear stiffness and strengths of these structures have been measured and compared with analytical predictions based upon plastic yielding and the various modes of lattice strut buckling. The compressive and shear strengths of hollow pyramidal lattices with relative densities of 1 to 6 % were 3 to 5 times those of solid pyramidal lattices of equivalent relative density and were accompanied by significant strength retention of the post buckled structures resulting in very high specific energy absorption.
Synthesis of single-phase polycrystalline Ca2Si powder and sintered compacts
Authors: Wen Cuilian , Nonomura Tomomi , Warashina Yoshifumi , Kubota Yoshihiro , Nakamura Tamotsu , Hayakawa Yasuhiro , Tanaka Miyoko , Isobe Kenji , Tatsuoka Hirokazu
Published: April 2011

Orthorhombic polycrystalline Ca2Si sintered compact bulk crystals were synthesized via a two-step treatment, and the experimental evaluation of the electrical and thermoelectric properties of Ca2Si is reported for the first time. First, single-phase Ca2Si powders were synthesized by the heat treatment of Mg2Si powders under a Ca vapor. Then Ca2Si sintered compacts were synthesized by the spark plasma sintering technique using the Ca2Si powders. It was found that single-phase Ca2Si sintered compacts were obtained when the sintering was carried out at temperatures lower than 673 K with high pressure of 300 MPa. The structural, electrical and thermoelectric properties of the Ca-silicide sintered compacts and their dependence on process conditions are discussed.
Phase-field simulation of diffusion couples in the Ni–Al system
Authors: Zhang Lijun , Steinbach Ingo , Du Yong
Published: April 2011

By linking thermodynamic and atomic mobility databases with two-dimensional phase-field simulation, the evolution of interdiffusion microstructures in a series of Ni–Al diffusion couples associated with the γ, γ′, and β-phases was studied. The formation and subsequent growth of the γ′-phase layer in β/γ and γ′ + β/γ diffusion couples reproduced the experimental observations well. Moreover, the effect of coherent strain on the γ – γ′ microstructural evolution, as well as that of an external compressive force on the γ + γ′/γ + γ′ diffusion couple, was investigated. The phase-field simulated concentration profiles of some of the Ni–Al diffusion couples were also compared with the corresponding experimental data and the results of one-dimensional DICTRA (DIffusion Controlled TRAnsformations) simulations. A discussion of the rafting direction was also made by comprehensively comparing the phase-field simulations with the predicted results from an elastic model.
Glass-forming ability and thermal stability of gas-atomized Zr50Cu40Al10 metallic glass powders
Authors: Yan Wei , Liu Yong , Zhu Yitian , Niu Sen
Published: April 2011

A Zr50Cu40Al10 (at.%) alloy was atomized by high pressure Ar gas, and the oxygen content, morphology, microstructure, phase composition, glass-forming ability and thermal stability of the as-atomized powders were investigated. Most of the powders are spherical in shape, but the surface morphologies are different for powders of different sizes. Powders with a size below 38 μm show an amorphous characteristic. The presence of oxygen in the metallic glass powders leads to heterogeneous nucleation of crystalline phases, and the smallest powders have the highest cooling rate, so even with oxygen contamination, it is possible to prevent the crystallization process. Oxygen decreases the thermal stability and the glass-forming ability of the metallic glass powders compared with the Zr50Cu40Al10 bulk metallic glass. The metallic glass powders also show a high thermal stability indicated by Trg, γ, and δ parameters.
On abnormal grain growth in nanocrystalline materials induced by small particles
Authors: Novikov Vladimir Y.
Published: April 2011

A duality in the behaviour of small particles, i. e. their ability to migrate along with some grain boundaries and, simultaneously, inability to move along with the others, has been shown to affect the character of the grain growth process. It is found by numerical simulations that a decrease in the particle mobility favours the evolution of abnormal grain growth and that the particle volume fraction, at low particle mobility, also affects its development. It has been supposed that these results explain the evolution of abnormal grain growth in compacted nanocrystalline materials where small voids could play the part of particles.
Mechanochemical synthesis of nanocrystalline lead selenide: industrial approach
Authors: Achimovičová Marcela , Baláž Peter , Ďurišin Juraj , Daneu Nina , Kováč Juraj , Šatka Alexander , Feldhoff Armin , Gock Eberhard
Published: April 2011

Mechanochemical synthesis of lead selenide PbSe nanoparticles was performed by high-energy milling of lead and selenium powder in a laboratory planetary ball mill and in an industrial eccentric vibratory mill. Structural properties of the synthesized lead selenide were characterized using X-ray diffraction that confirmed crystalline nature of PbSe nanoparticles. The average size of PbSe crystallites of 37 nm was calculated from X-ray diffraction data using the Williamson – Hall method. The methods of particle size distribution analysis, specific surface area measurement, scanning electron microscopy and transmission electron microscopy were used for characterization of surface, mean particle size, and morphology of PbSe. An application of industrial mill verified a possibility of the synthesis of a narrow bandgap semiconductor PbSe at ambient temperature and in a relatively short reaction time.
Structural, thermal, electrical and mechanical properties of nanosilica-composite polymer electrolytes
Authors: Johan Mohd Rafie , Jimson Sharon Anak , Ghazali Nadiah , Zahari Nurhannie Azrin Mohd , Redha Nurul Farzana
Published: April 2011

We synthesized a new kind of solid polymer electrolyte with polyethylene oxide (PEO) as a host, lithium triflate (LiCF3SO3) as a salt, mixtures of ethylene carbonate (EC) and dibuthyl phthalate (DBP) as a double plasticizer and nanosilica (SiO2) as a filler using the solution casting technique. Nanosilica was produced through mechanical milling with a size range of 60 – 80 nm as shown by transmission electron microscopy. X-ray diffraction patterns confirmed the complex formation of the PEO – LiCF3SO3– EC – DBP – SiO2system. The optimum conductivity value at room temperature was 5.1 · 10−3S cm−1for 4 wt.% of SiO2. Differential scanning calorimetry results show that the glass transition temperature of the composite polymer electrolyte was found to increase when SiO2was added. Addition of salt and plasticizers decreases the Young's modulus of the polymer electrolyte. However, the addition of 4 wt.% SiO2increases the Young's modulus value from 5.1 · 10− 2to 1.08 · 10− 1MPa.
Inferences for the Lead Time in Breast Cancer Screening Trials under a Stable Disease Model
Authors: Shows Justin , Wu Dongfeng
Published: April 2011

We estimated the effects on the lead time for women participating in a long-term breast cancer screening program when the screening sensitivities and disease progression are independent of age. The lead time, or time by which a diagnosis is advanced by screening, is one of the major concerns of any cancer screening program, which we consider to include both a mammogram and physical examination. Using estimates of test sensitivities and mean sojourn times previously calculated by other authors from observed data, we estimated properties of the lead time. We utilized the model for the lead time derived by other authors and ran simulations for different screening program designs, concentrating on screening interval lengths of 0.5 years, 1 year, 1.5 years, and 2 years. These estimates were based on a long-term screening program from age 50 to 80. For each six-month decrease in screening interval length, we estimated the percent increase in mean lead time, as well as the percent increase in the proportion of clinical patients who will have their cancer detected at a screening exam.
Lymph Node Metastasis of Gastric Cancer
Authors: Akagi Tomonori , Shiraishi Norio , Kitano Seigo
Published: April 2011

Despite a decrease in incidence in recent decades, gastric cancer is still one of the most common causes of cancer death worldwide [1]. In areas without screening for gastric cancer, it is diagnosed late and has a high frequency of nodal involvement [1]. Even in early gastric cancer (EGC), the incidence of lymph node (LN) metastasis exceeds 10%; it was reported to be 14.1% overall and was 4.8 to 23.6% depending on cancer depth [2]. It is important to evaluate LN status preoperatively for proper treatment strategy; however, sufficient results are not being obtained using various modalities. Surgery is the only effective intervention for cure or long-term survival. It is possible to cure local disease without distant metastasis by gastrectomy and LN dissection. However, there is no survival benefit from surgery for systemic disease with distant metastasis such as para-aortic lymph node metastasis [3]. Therefore, whether the disease is local or systemic is an important prognostic indicator for gastric cancer, and the debate continues over the importance of extended lymphadenectomy for gastric cancer. The concept of micro-metastasis has been described as a prognostic factor [4-9], and the biological mechanisms of LN metastasis are currently under study [10-12]. In this article, we review the status of LN metastasis including its molecular mechanisms and evaluate LN dissection for the treatment of gastric cancer.
The Role of Tumour Stroma in Colorectal Cancer Invasion and Metastasis
Authors: Conti John , Thomas Gareth
Published: April 2011

Colorectal cancer (CRC) is a major cause of mortality in western society with a 5-year survival of approximately 50%. Metastasis to the liver and lungs is the principal cause of death and occurs in up to 25% of patients at presentation. Despite advances in available techniques for treating metastases, the majority of patients remain incurable and existing adjuvant therapies such as chemotherapy are only of limited effectiveness. Understanding the molecular mechanisms underlying the metastatic process may allow us to identify those at greatest risk of recurrence and discover new tumour targets to prevent disease progression. It is now apparent that tumour stroma plays an important role in promoting tumour progression. A pronounced desmoplastic reaction was associated with a reduced immune response and has been shown to be an independent poor prognostic indicator in CRC and cancer recurrence. Determining the cause(s) and effect(s) of this stromal response will further our understanding of tumour cell/stromal interactions, and will help us identify prognostic indicators for patients with CRC. This will not only allow us to target our existing treatments more effectively, we also aim to identify novel and more specific therapeutic targets for the treatment of CRC which will add to our current therapeutic options.
X Inactivation and Progenitor Cancer Cells
Authors: Agrelo Ruben
Published: April 2011

In mammals, silencing of one of the two X chromosomes is necessary to achieve dosage compensation. The 17 kb non-coding RNA called Xist triggers X inactivation. Gene silencing by Xist can only be achieved in certain contexts such as in cells of the early embryo and in certain hematopoietic progenitors where silencing factors are present. Moreover, these epigenetic contexts are maintained in cancer progenitors in which SATB1 has been identified as a factor related to Xist-mediated chromosome silencing.
Predictive Factors of the Response of Rectal Cancer to Neoadjuvant Radiochemotherapy
Authors: Spolverato Gaya , Pucciarelli Salvatore , Bertorelle Roberta , De Rossi Anita , Nitti Donato
Published: April 2011

Locally advanced rectal cancer is currently treated with pre-operative radiochemotherapy (pRCT), but the response is not uniform. Identification of patients with higher likelihood of responding to pRCT is clinically relevant, as patients with resistant tumors could be spared exposure to radiation or DNA-damaging drugs that are associated with adverse side effects. To highlight predictive biomarkers of response to pRCT, a systematic search of PubMed was conducted with a combination of the following terms: “rectal”, “predictive”, “radiochemotherapy”, “neoadjuvant”, “response” and “biomarkers”. Genetic polymorphisms in epithelial growth factor receptor (EGFR) and thymidylate synthase (TS) genes, the expression of several markers, such as EGFR, bcl-2/bax and cyclooxygenase (COX)-2, and circulating biomarkers, such as serum carcinoembryonic antigen (CEA) level, are promising as predictor markers, but need to be further evaluated. The majority of the studies did not support the predictive value of p53, while the values of Ki-67, TS and p21 is still controversial. Gene expression profiles of thousands of genes using microarrays, microRNA studies and the search for new circulating molecules, such as human telomerase reverse transcriptase mRNA and cell-free DNA, are providing interesting results that might lead to the identification of new useful biomarkers. Evaluation of biomarkers in larger, prospective trials are required to guide therapeutic strategies.
Synthesis and Crystal Structure of 9-(4,6-dichloro-1,3,5-triazin-2-yl)-9H-carbazole
Authors: Saeed Aamer , Kazmi Madiha , Samra Shahid Ameen , Flörke Ulrich
Published: April 2011

A carbazole-triazine hybrid was prepared by addition-elimination between carbazole and 2,4,6-trichlorotriazine in the presence of base. The compound shows intensely blue fluorescence both in solution and solid state when irradiated with UV-radiation. The structure of (3) was supported by the spectroscopic data and unambiguously confirmed by the single crystal X-ray diffraction data. It was crystallized in the monoclinic space group C2/c with unit cell dimensions a = 20.280(3), b = 8.0726(14), c = 16.005(3) Å, α = γ = 90°, β = 98.947(3)°, V = 2588.3(8) Å³, Z = 8.
A Cost-Effectiveness Analysis of India’s 2008 Prohibition of Smoking in Public Places in Gujarat
Authors: Donaldson Elisabeth A. , Waters Hugh R. , Arora Monika , Varghese Beena , Dave Paresh , Modi Bhavesh
Published: April 2011

Tobacco smoking and exposure to secondhand tobacco smoke are associated with disability and premature mortality in low and middle-income countries. The aim of this study was to assess the cost-effectiveness of implementing India’s Prohibition of Smoking in Public Places Rules in the state of Gujarat, compared to implementation of a complete smoking ban. Using standard cost-effectiveness analysis methods, the cost of implementing the alternatives was evaluated against the years of life saved and cases of acute myocardial infarction averted by reductions in smoking prevalence and secondhand smoke exposure. After one year, it is estimated that a complete smoking ban in Gujarat would avert 17,000 additional heart attacks and gain 438,000 life years (LY). A complete ban is highly cost-effective when key variables including legislation effectiveness were varied in the sensitivity analyses. Without including medical treatment costs averted, the cost-effectiveness ratio ranges from $2 to $112 per LY gained and $37 to $386 per acute myocardial infarction averted. Implementing a complete smoking ban would be a cost saving alternative to the current partial legislation in terms of reducing tobacco-attributable disease in Gujarat.
Phenols in Leaves and Bark of Fagus sylvatica as Determinants of Insect Occurrences
Authors: Petrakis Panos V. , Spanos Kostas , Feest Alan , Daskalakou Evangelia
Published: April 2011

Beech forests play an important role in temperate and north Mediterranean ecosystems in Greece since they occupy infertile montane soils. In the last glacial maximum, Fagus sylvatica (beech) was confined to Southern Europe where it was dominant and in the last thousand years has expanded its range to dominate central Europe. We sampled four different beech forest types. We found 298 insect species associated with beech trees and dead beech wood. While F. sylvatica and Quercus (oak) are confamilial, there are great differences in richness of the associated entomofauna. Insect species that inhabit beech forests are less than one fifth of those species living in oak dominated forests despite the fact that beech is the most abundant central and north European tree. There is a distinct paucity of monophagous species on beech trees and most insect species are shared between co-occurring deciduous tree species and beech. This lack of species is attributed to the vegetation history and secondary plant chemistry. Bark and leaf biophenols from beech indicate that differences in plant secondary metabolites may be responsible for the differences in the richness of entomofauna in communities dominated by beech and other deciduous trees.
Data-Driven Approaches for Computation in Intelligent Biomedical Devices: A Case Study of EEG Monitoring for Chronic Seizure Detection
Authors: Verma Naveen , Lee Kyong Ho , Shoeb Ali
Published: April 2011

Intelligent biomedical devices implies systems that are able to detect specific physiological processes in patients so that particular responses can be generated. This closed-loop capability can have enormous clinical value when we consider the unprecedented modalities that are beginning to emerge for sensing and stimulating patient physiology. Both delivering therapy (e.g., deep-brain stimulation, vagus nerve stimulation, etc.) and treating impairments (e.g., neural prosthesis) requires computational devices that can make clinically relevant inferences, especially using minimally-intrusive patient signals. The key to such devices is algorithms that are based on data-driven signal modeling as well as hardware structures that are specialized to these. This paper discusses the primary application-domain challenges that must be overcome and analyzes the most promising methods for this that are emerging. We then look at how these methods are being incorporated in ultra-low-energy computational platforms and systems. The case study for this is a seizure-detection SoC that includes instrumentation and computation blocks in support of a system that exploits patient-specific modeling to achieve accurate performance for chronic detection. The SoC samples each EEG channel at a rate of 600 Hz and performs processing to derive signal features on every two second epoch, consuming 9 μJ/epoch/channel. Signal feature extraction reduces the data rate by a factor of over 40×, permitting wireless communication from the patient’s head while reducing the total power on the head by 14×.
4-(3,5-Dibromo-4-hydroxyphenyl)-3-butoxycarbonyl-5-ethoxycarbonyl-2-methyl-6-phenyl-1,4-dihydropyridine
Authors: Wang Zhen , Liu Qingjian
Published: April 2011

One-pot two-step Hantzsch synthesis of 4-(3,5-dibromo-4-hydroxyphenyl)-3- butoxycarbonyl-5-ethoxycarbonyl-2-methyl-6-phenyl-1,4-dihydropyridine under solvent- and catalyst-free conditions promoted with microwave irradiation is presented.
Oral Administration of Skin Gelatin Isolated from Chum Salmon (Oncorhynchus keta) Enhances Wound Healing in Diabetic Rats
Authors: Zhang Zhaofeng , Zhao Ming , Wang Junbo , Ding Ye , Dai Xiaoqian , Li Yong
Published: April 2011

Care for diabetic wounds remains a significant clinical problem. The present study was aimed at investigating the effect of skin gelatin from Chum Salmon on defective wound repair in the skin of diabetic rats. Full-thickness excisional skin wounds were made in 48 rats, of which 32 were diabetes. The diabetic rats were orally treated daily for 14 days with skin gelatin from Chum Salmon (2 g/kg) or its vehicle. Sixteen non-diabetic control rats received the same amount of water as vehicle-treated non-diabetic rats. Rats were killed to assess the rate of wound closure, microvessel density (MVD), vascular endothelial growth factor (VEGF), hydroxyproline (HP) contents in wound tissues and nitrate in plasma and wound tissue at 7 and 14 days after wounding. Skin gelatin-treated diabetic rats showed a better wound closure, increased MVD, VEGF, hyproxyproline and NO contents and a reduced extent of inflammatory response. All parameters were significant (P < 0.05) in comparison to vehicle-treated diabetic group. In light of our finding that skin gelatin of Chum Salmon promotes skin wound repair in diabetic rats, we propose that oral administration of Chum Salmon skin gelatin might be a beneficial method for treating wound disorders associated with diabetes.
Thiophene Derivatives with Antileishmanial Activity Isolated from Aerial Parts of Porophyllum ruderale (Jacq.) Cass.
Authors: Takahashi Helena Teru , Novello Cláudio Roberto , Ueda-Nakamura Tânia , Filho Benedito Prado Dias , Palazzo de Mello João Carlos , Nakamura Celso Vataru
Published: April 2011

Porophyllum ruderale (Jacq.) Cass. is a plant native to Brazil and in the northwest region of the state of Paraná, Brazil, aerial parts of P. ruderale have been used popularly in the treatment of lesions caused by Leishmania sp.. In this study the antileishmanial and cytotoxic activities of the crude extract, fractions, and isolated compounds from aerial parts of P. ruderale was evaluated. The dichloromethane extract was submitted to chromatography to yield compounds active against Leishmania amazonensis. Their structures were established by comparison of their spectroscopic data with literature values. The activities of crude extract against promastigote and axenic amastigote forms of L. amazonensis (IC50) were 60.3 and 77.7 μg/mL, respectively. Its cytotoxic activity against macrophage cells (CC50) was 500 μg/mL. The thiophene derivatives isolated were: 5-methyl-2,2':5',2"-terthiophene (compound A) and 5'-methyl–[5–(4–acetoxy-1–butynyl)]–2,2'-bithiophene (compound B). The activity of compound A against promastigote and axenic amastigote forms were 7.7 and 19.0 μg/mL and of compound B were 21.3 and 28.7 μg/mL, respectively. The activity of the isolated compounds against promastigote and axenic amastigote forms was better than that of the crude extract and more selective against protozoa than for macrophage cells.
Study of the Biological Activity of Novel Synthetic Compounds with Antiviral Properties against Human Rhinoviruses
Authors: Laconi Samuela , Madeddu Maria A. , Pompei Raffaello
Published: April 2011

Picornaviridae represent a very large family of small RNA viruses, some of which are the cause of important human and animal diseases. Since no specific therapy against any of these viruses currently exists, palliative symptomatic treatments are employed. The early steps of the picornavirus replicative cycle seem to be privileged targets for some antiviral compounds like disoxaril and pirodavir. Pirodavir’s main weakness is its cytotoxicity on cell cultures at relatively low doses. In this work some original synthetic compounds were tested, in order to find less toxic compounds with an improved protection index (PI) on infected cells. Using an amino group to substitute the oxygen atom in the central chain, such as that in the control molecule pirodavir, resulted in decreased activity against Rhinoviruses and Polioviruses. The presence of an -ethoxy-propoxy- group in the central chain (as in compound I-6602) resulted in decreased cell toxicity and in improved anti-Rhinovirus activity. This compound actually showed a PI >700 on HRV14, while pirodavir had a PI of 250. These results demonstrate that modification of pirodavir’s central hydrocarbon chain can lead to the production of novel derivatives with low cytotoxicity and improved PI against some strains of Rhinoviruses.
Gombapyrones E and F, New α-Pyrone Polyenes Produced by Streptomyces sp. KMC-002
Authors: Park Hyun Bong , Yang Hyun Ok , Lee Kang Ro , Kwon Hak Cheol
Published: April 2011

Microorganism-derived polyene polyketides have been shown to display a variety of biological activities and have attracted great interest due to their structurally intriguing chemical diversity. Two new polyenes were isolated from a culture broth of Streptomyces sp. KMC-002 obtained from a soil sample in an abandoned mine. The structures of these compounds were determined to be α-pyrone-containing polyene analogues through analyses of HRFABMS, UV and NMR data, and were named Gombapyrones E (1) and F (2). Gombapyrone E (1) showed antibacterial activity against Micrococcus luteus, Enterococcus hirae, Staphylococcus aureus and MRSA.
Expanding the Antimalarial Drug Arsenal—Now, But How?
Authors: Grimberg Brian T. , Mehlotra Rajeev K.
Published: April 2011

The number of available and effective antimalarial drugs is quickly dwindling. This is mainly because a number of drug resistance-associated mutations in malaria parasite genes, such as crt, mdr1, dhfr/dhps, and others, have led to widespread resistance to all known classes of antimalarial compounds. Unfortunately, malaria parasites have started to exhibit some level of resistance in Southeast Asia even to the most recently introduced class of drugs, artemisinins. While there is much need, the antimalarial drug development pipeline remains woefully thin, with little chemical diversity, and there is currently no alternative to the precious artemisinins. It is difficult to predict where the next generation of antimalarial drugs will come from; however, there are six major approaches: (i) re-optimizing the use of existing antimalarials by either replacement/rotation or combination approach; (ii) repurposing drugs that are currently used to treat other infections or diseases; (iii) chemically modifying existing antimalarial compounds; (iv) exploring natural sources; (v) large-scale screening of diverse chemical libraries; and (vi) through parasite genome-based (“targeted”) discoveries. When any newly discovered effective antimalarial treatment is used by the populus, we must maintain constant vigilance for both parasite-specific and human-related factors that are likely to hamper its success. This article is neither comprehensive nor conclusive. Our purpose is to provide an overview of antimalarial drug resistance, associated parasite genetic factors (1. Introduction; 2. Emergence of artemisinin resistance in P. falciparum), and the antimalarial drug development pipeline (3. Overview of the global pipeline of antimalarial drugs), and highlight some examples of the aforementioned approaches to future antimalarial treatment. These approaches can be categorized into “short term” (4. Feasible options for now) and “long term” (5. Next generation of antimalarial treatment—Approaches and candidates). However, these two categories are interrelated, and the approaches in both should be implemented in parallel with focus on developing a successful, long-lasting antimalarial chemotherapy.
Photoinduced electron-transfer chemistry of the bielectrophoric N-phthaloyl derivatives of the amino acids tyrosine, histidine and tryptophan
Authors: Griesbeck Axel G , Neudörfl Jörg , de Kiff Alan
Published: April 2011

The photochemistry of phthalimide derivatives of the electron-rich amino acids tyrosine, histidine and tryptophan 8–10 was studied with respect to photoinduced electron-transfer (PET) induced decarboxylation and Norrish II bond cleavage. Whereas exclusive photodecarboxylation of the tyrosine substrate 8 was observed, the histidine compound 9 resulted in a mixture of histamine and preferential Norrish cleavage. The tryptophan derivative 10 is photochemically inert and shows preferential decarboxylation only when induced by intermolecular PET.
Vitamin D is Linked to Carotid Intima-Media Thickness and Immune Reconstitution in HIV-Positive Individuals
Authors: Ross Allison C , Judd Suzanne , Kumari Meena , Hileman Corrilynn , Storer Norma , Labbato Danielle , Tangpricha Vin , McComsey Grace A
Published: April 2011

Background

Patients with HIV infection are at increased risk of cardiovascular disease (CVD). Vitamin D insufficiency has been associated with increased CVD risk in non-HIV populations. This study sought to determine the relationship between vitamin D status and markers of CVD and HIV-related factors in HIV-positive patients.

Methods

Patients with HIV infection on antiretroviral therapy and healthy controls were prospectively enrolled. Fasting lipids, glucose, insulin, inflammatory markers (soluble tumour necrosis factor-α receptor I, interleukin-6 and high-sensitivity C-reactive protein) and endothelial markers (soluble intercellular adhesion molecule-1 and soluble vascular cell adhesion molecule-1) were measured. Fasting 25-hydroxyvitamin D (25(OH)D) was measured from stored serum samples. The internal carotid artery and common carotid artery (CCA) intima-media thickness (IMT) were measured in a subset of HIV-positive patients. Baseline cross-sectional data were analysed.

Results

A total of 149 HIV-positive patients (56 with carotid IMT) and 34 controls were included. Controls had higher adjusted mean 25(OH)D levels than HIV-positive patients ( P=0.02). In multivariable linear regression among the HIV-positive patients, 25(OH)D was positively associated with CD4+ T-cell restoration after antiretroviral therapy (ΔCD4 = current - nadir CD4+ T-cell; P<0.01), but was not associated with inflammatory or endothelial markers. In multivariable logistic regression, odds of having CCA IMT above the median were more than 10x higher in those with lower 25(OH)D levels (OR=10.62, 95% CI 1.37-82.34; P<0.01).

Conclusions

Vitamin D status in HIV-positive patients was positively associated with improved immune restoration after antiretroviral therapy and negatively associated with CCA IMT. These findings suggest that vitamin D may play a role in HIV-related CVD and in immune reconstitution after antiretroviral therapy.
Deep sea megafaunal assemblages off the northern Iberian slope related to environmental factors
Authors: Serrano Alberto , Sánchez Francisco , Punzón Antonio , Velasco Francisco , Olaso Ignacio
Published: April 2011

Four deep sea fish and invertebrate assemblages from the northern Spanish slope were identified and related to geographic and bathymetric factors. The Peñas Cape comprises a boundary area splitting the more productive, wider and sandy western shelf from the less productive, narrow and muddy eastern part. The four faunal assemblages described were a shelf-slope transition assemblage (SST, 400-500 m); two upper slope assemblages (500-650 m), one corresponding to the western area of Cape Peñas and one to the eastern area; and a middle slope assemblage (650-750 m). The SST was dominated by plankton-feeding fish and was hence less diverse than the other strata. This dominance was more evident west of the Peñas Cape, where upwelling was stronger. Regarding invertebrates, plankton-feeding fish and benthos-feeding invertebrates dominated the SST, whereas zooplankton-feeding and deposit-feeding invertebrates dominated the middle slope. The western assemblages were richer in species as a consequence of a more complex food web, especially of guilds related to water column production: plankton-feeding fish and filter- and zooplankton-feeding invertebrates.
Management of the stalked barnacle (Pollicipes pollicipes) fishery in the Berlengas Nature Reserve (Portugal): evaluation of bag and size limit regulation measures
Authors: Jacinto David , Cruz Teresa , Silva Teresa , Castro João J.
Published: April 2011

The stalked barnacle Pollicipes pollicipes (Gmelin, 1790) is an important shellfish resource in Portugal. Due to the social-economic importance of barnacle harvesting, a management plan aimed at achieving a controlled and sustainable activity (including temporal and spatial closures, rotational harvesting, a limited number of harvesting licenses, bag and size limits for catches and catch reporting) was implemented in 2000 at the Berlengas Nature Reserve (RNB) in central Portugal. We evaluated the bag and size limits imposed by the management plan, performing observations on harvesting activity and asking licensed harvesters and RNB staff about these measures. Both inquiries and observations suggest that licensed harvesters are not following the bag and size limits imposed. Mean amounts captured in RNB varied from 14 to 24 kg per harvester/day, but 25% of the observations corresponded to higher catches per individual than the total amount allowed (20 kg). Only half of the sampled amounts (taken in autumn 2005 and 2006) were in agreement with the size limit regulation and 50% of the total biomass comprised individuals of maximal rostro-carinal length (RC) ≥ 25 mm. For most harvesters, size limit is the most difficult management rule to fulfil. Both harvesters and RNB staff agree that surveillance is scarce and is a major problem of this fishing activity. In order to achieve a more sustainable use of this resource, we propose the implementation of a more effective surveillance and monitoring plan, the definition of a unique landing site, the maintenance of the bag limit (20 kg) and a reduction of the size limit (50% of total biomass comprising individuals ≥ 22 mm RC).
Maturity and batch fecundity of the European hake (Merluccius merluccius, Linnaeus, 1758) in the eastern central Atlantic
Authors: El Habouz Hammou , Recasens Laura , Kifani Souad , Moukrim Abdellatif , Bouhaimi Abdellah , El Ayoubi Salaheddine
Published: April 2011

The reproductive biology of the European hake (Merluccius merluccius, Linnaeus, 1758) was studied on the eastern central Atlantic Moroccan coast from November 2001 to December 2003. The sex ratio was close to 1:1 for the specimens with a total length of less than 45 cm. European hake spawned all year round, though two spawning peaks were recorded with a certain interannual variability: the first and main peak in winter and a secondary intermittent peak in summer. Length at first maturity was estimated as 28.6 cm and 33.8 cm total length for males and females, respectively. These values are closer to Mediterranean than Atlantic hake values. The mean batch fecundity was 299872 eggs ind–1. The relative batch fecundity was estimated as 228 eggs per gram of gutted weight. Batch fecundity increased proportionally with fish length and weight. The batch fecundity of European hake in the Moroccan Atlantic area is higher than that in northern Atlantic and northwestern Mediterranean areas.
Dactylamblyops corberai n. sp., a new mysid (Crustacea: Mysida) from the deep Mediterranean Sea
Authors: San Vicente Carlos , Cartes Joan E.
Published: April 2011

A new Erythropinae mysid, Dactylamblyops corberai n. sp., is described from specimens sampled with a 500-mm plankton net attached to a bottom trawl in the Ionian Sea (eastern Mediterranean). This new species is the first Dactylamblyops species described from the Mediterranean Sea. Based on a revision of additional material from several cruises made in recent years, we conclude that D. corberai is a widespread species in the deep Mediterranean near-bottom suprabenthic community at depths between 398 and 1859 m. The main distinguishing features of D. corberai are the shape of the eyes and their ocular process, and the shape of the labrum with two rows of clusters of short setules and two areas covered with small, scale-like protrusions not described in any other species of the genus. D. corberai belongs to the morphological hodgsoni group of Dactylamblyops species.
Deep-water fishing tactics of the Spanish fleet in the Northeast Atlantic. Seasonal and spatial distribution
Authors: Punzón Antonio , Serrano Alberto , Castro José , Abad Esther , Gil Juan , Pereda Pilar
Published: April 2011

The classification and identification of all the Spanish fishing activity targeting deep-sea species was conducted using a non-hierarchical classification technique designed for large matrices (CLARA). Otter trawl and set longlines were the main gears used in deep-sea ecosystems. The otter trawl fleet conducted 3 deep-sea fishing tactics. The only otter trawl fishing tactic targeting deep-sea species was that working in the VI ICES Division and targeting Alepocephalus baiirdi. The other 2 otter trawl fishing tactics targeted shallower shelf demersal resources, deep-sea species being secondary (Phycis blennoides). The longline fleet carried out 7 fishing tactics targeting deep-sea species (Molva spp.; deep water sharks; P. blennoides; Pagellus bogaraveo; and Trichiuridae) and 2 fishing tactics targeting Conger conger, which perform as deep-sea fishing tactics in the narrow continental shelf area. This classification, together with knowledge regarding their seasonal performance and spatial distribution, may help to design fisheries sampling protocols and to improve the management of these fleets, thus reducing their impact on deep-sea habitats.
Taxonomic notes on Poecillastra sponges (Astrophorida: Pachastrellidae), with the description of three new bathyal southeastern Pacific species
Authors: Carvalho Mariana S. , Desqueyroux-Faúndez Ruth , Hajdu Eduardo
Published: April 2011

Three new species of Poecillastra are described here from bathyal waters off central Chile. P. antonbruunae n. sp. is diagnosed by its two categories of oxeas, the smaller one only up to 621 μm in length, and calthrops as the sole triaene category; P. sinetridens n. sp. by the possession of oxeas larger than 3000 μm long, microxeas which can be over 300 μm long, and absence of triaenes; and P. maremontana n. sp. by its three categories of oxeas, three categories of streptasters (one of spirasters and two of plesiasters), one category of calthrops and centrotylote microxeas. Comments upon other Poecillastra and an identification key for Pacific species of the genus are given. Evolutionary hypotheses are discussed for the genus given the distribution of spicule morphotypes, as well as the recurrent phenomenon of spicule loss in Astrophorida. Five species of Pachastrella are transferred here to Poecillastra on the basis of their possession of microxeas instead of microrhabds, viz. P. cribrum Lebwohl, 1914; P. dilifera de Laubenfels, 1934 [sensu Dickinson (1945)]; P. fusca Lebwohl, 1914; P. incrustata Bergquist, 1968; and P. scrobiculosa Lebwohl, 1914. We recognize 28 species of Poecillastra, 19 of them occurring in the Pacific Ocean.