bluuebunny/crossref_metadata_2025 huggingface dataset:
COMPOSITE STEEL AND CONCRETE BRIDGE CONSTRUCTION IN SOUTHERN RHODESIA.
Authors: MASON A F , DUNCAN M A G
Published: November 2010

An attempt is made through the Paper to introduce, as a basis for discussion, design standards for composite structural steel and reinforced concrete decks for. modem highway bridges. The Paper describes the design standards developed by the Authors in the absence of any current code to cover the increasing number of composite structures now being erected in Southern Rhodesia.

The Authors have drawn heavily on previously published technical information from both British and American sources, and have endeavoured to compile an ad hoc code to suit the prevailing conditions in the Federation. Little opportunity has been available for experimental work to verify several unsolved problems.

The question of the dynamic stability of decks subject to a relatively high live-load/dead-load ratio, the possibility of incorporating prestressed precast concrete units in the composite compression zone, the prestressinogf steel during construction, and the effective slab width and transverse distribution usingo pen frames, are subjects which the Authors would like to devote considerable time to in the experimental and research laboratory, particularly in the sphere of continuity.
Voidage assessment of concrete using digital image processing
Authors: True G. , Searle D. , Sear L. , Khatib J.
Published: November 2010

This paper describes an objective means of assessing the amount of voidage found within the curved surface of concrete core samples that has been developed by mechanically rolling core samples above a modified flatbed desktop scanner so as to align with the scanning charged coupled device illuminated cross-head. A freely distributed software program was used to process all images to determine percentage voidage and voidage size distribution among other attributes. This work shows that the size, shape and distribution of air voids and aggregate characteristics can be determined using core samples scanned over modified flatbed desktop scanners. A proprietary office desktop scanner with a resolution of 1200 dpi was used.
Analytical approach to factors affecting long-term tension stiffening
Authors: Zanuy C.
Published: November 2010

It is widely accepted that tension stiffening of reinforced concrete reduces in the long term. In the codes of practice, this is accounted for by means of a modification in the empirical parameters to interpolate the average response of the reinforced member between the states I (uncracked) and II (bare steel). This average response is actually the result of the interaction of the different time-dependent mechanisms which develop in the element. In a tension member, the behaviour is mainly influenced by concrete creep and shrinkage and time-dependent bond deterioration. The role played by these processes is still unknown. An analytical approach is developed in this paper in order to understand the influence of such processes in the long-term decay of tension stiffening in tension members. The model is able to explain the experimental response of specimens tested in the literature and the results show the major influence of the time-dependent bond deterioration (bond creep and bond stiffness modification), rather than concrete creep and shrinkage.
Influence of strain rates and load histories on the tensile damage behaviour of concrete
Authors: Xiao S. , Li H. , Monteiro P.J.M.
Published: November 2010

Concrete structures are often subjected to dynamic loads, such as seismic, blast or impact loads. Under such loads, distinct changes may occur in the dynamic and damage behaviour of concrete. This paper presents the results of dynamic tensile tests of plain concrete specimens with axial strain rates ranging from 10−5/s to 10−1/s that were carried out on a servo-testing machine. Observed stages of damage evolution are divided into three phases: undeveloped, steadily developed and unsteadily developed. This study found that the stress threshold ratio of ultimate strength increases with strain rate, and that the initial tangent elastic modulus and Poisson's ratio are independent of the strain rate for the test specimens. Moreover, the tensile strength and critical strain of concrete increased approximately linearly with the logarithm of the strain rate, and an experimental relationship between strain rates and tensile strength, critical strain was established. Furthermore, dynamic tensile damage tests of concrete were carried out with axial strain rates ranging from 10−5/s to 10−2/s. The effects of loading histories on dynamic tensile strengths, dynamic stress–strain curves, and dynamic damage behaviour of concrete were studied. Results indicate that both dynamic tensile strengths and damage thresholds of concrete decreased while the given rated loading was applied compared with those samples that were not subjected to the load history. However, damage of concrete at the same stress ratio and strain ratio increased with the increasing load history.
Heat evolution due to cement hydration in foamed concrete
Authors: Tarasov A.S. , Kearsley E.P. , Kolomatskiy A.S. , Mostert H.F.
Published: November 2010

Foamed concrete is nowadays considered an attractive building material as a result of flexible production technology and excellent target properties, along with economic benefits. Heat generated in foamed concrete during cement hydration is found to differ significantly from normal-weight concrete. Foamed concrete that is placed in a regular-shaped well-insulated mould experiences significant core temperature rises and, although several documents discussing the thermal effect in foamed concrete have been published, there is still a lack of information revealing the interrelations of foamed concrete parameters and their effect on temperature rise. Laboratory tests were carried out with foamed concrete of variable densities and volumes under semi-adiabatic curing conditions. The observed trends were used as the initial input for a mathematical model of temperature prediction in foamed concrete. The heat evolution process under real production conditions can be controlled by optimising the mix composition. If the thermal energy in foamed concrete is properly employed it can result in considerable improvement of the final product characteristics while production costs decrease.
Shear performance of precast SHCC infill walls for seismic retrofitting of non-ductile frames
Authors: Kim S.-W. , Yun H.-D. , Choi G.-B.
Published: November 2010

Infilled frames have been investigated by many researchers during the last few decades. It is noted that frame structures incorporating infill walls have shown definite economic and performance advantages over conventional rigid-frame structures when the structures are required to resist large lateral loads due to earthquake ground motion. The objectives of this study are to evaluate the effect of notches in the infill walls and to investigate the effect of the ductility of cementitious composites, particularly strain hardening and multiple cracking, on the seismic performance of infill walls subjected to displacement reversals. The experimental investigation consisted of cyclic loading tests on four 1/3-scale models of infill walls. Material ductility and notches in the infill walls were the main variables in the test. In the test results, as expected, strain-hardening cementitious composite infill wall specimens showed multiple crack patterns due to the bridging of fibres and stress redistribution in the cement matrix. Although the strain-hardening cementitious composite infill wall had a less effective section near the notched mid-section, it showed a higher strength and energy dissipation capacity than those of the reinforced concrete infill wall specimen without a notched mid-section.
Investigation of CO2 Diffusivity in Heavy Oil Using X-Ray Computer-Assisted Tomography Under Reservoir Conditions
Authors: Song L.. , Kantzas A.. , Bryan J..
Published: November 2010

Since the 1950’s, the use of carbon dioxide to increase heavy oil recovery has attract more attention from industry and laboratory research. The injection of carbon dixode has shown technical and economical advantages for enhancing heavy oil and bitumen recovery, because it can effectively reduce viscosity under the reservoir conditions. When carbon dioxide is injected into the reservoir, it partially dissolves into the heavy oil and mass transfer is the first mechanism to occur. Consequently, the accurate prediction and evaluation of the diffusion coefficient of carbon dioxide in heavy oil is one of the key parameters to develop technology for extraction of heavy oil in a feasible and cost-effective way. However, few experimental data for diffusivity of carbon dioxide in heavy oil are available in the literature. Therefore, this study conducted in order to add to the existing the laboratory data for evaluation and calculation of diffusion coefficient of carbon dioxide into heavy oil. In the past, experimental methods used to determine the diffusion coefficient of a gas in heavy oil were conducted under a constant gas pressure, which assumed that oil phase can be contacted with infinite gas at a fixed pressure. In this study, by employing X-ray Computed Assisted Tomography (CAT) and a non-iterative finite volume method, the purpose is to evaluate and compare experimental diffusion coefficients of carbon dioxide in heavy oil under the constant pressure and decaying pressue at the same time. Moreover, investigation of impacts of pressure on diffusion coefficients is conducted.

It is found that the diffusvity of carbon dioxide in heavy oil is sensitive to the system pressure. The comparison between carbon dioxide diffusion coefficients under the constant pressure and those measured under the decaying pressrue showed an obvious difference. The results of study are essential for understanding oil recovery through carbon dioxide injection.
Obsessive–Compulsive Symptoms in First Episode Psychosis and in Subjects at Ultra High Risk for Developing Psychosis; Onset and Relationship to Psychotic Symptoms
Authors: Sterk Bouke , Lankreijer Kay , Linszen Don H , de Haan Lieuwe
Published: November 2010

Objective: To determine the prevalence of obsessive–compulsive symptoms and obsessive–compulsive disorder in patients with schizophrenia or related disorders or subjects at ultra high risk for development of psychosis. Secondly, to determine the time of occurrence of obsessive–compulsive symptoms related to the onset of first psychosis.

Method: We collected data on all patients who were referred consecutively to our specialized clinic for first episode psychosis patients and ultra high risk subjects in Amsterdam between 1 July 2006 and 1 July 2008. Diagnosis of psychotic disorders was established using the Comprehensive Assessment of Symptoms and History schedule. Obsessions and compulsions were defined in accordance with DSM-III-R criteria and assessed by clinicians. We analyzed the onset of obsessive–compulsive symptoms and its relation to the onset of first episode psychosis.

Results: When a strict definition of obsessive–compulsive symptoms is used, 9.3% (n = 18) of patients with schizophrenia or a related disorder exhibited obsessive–compulsive symptoms and 1.5% also met criteria for obsessive–compulsive disorder. The onset of obsessive–compulsive symptoms occurred before, concurrent with and after onset of first episode psychosis in the following proportion of patients: 7/18, 3/18, 8/18. We found a prevalence of 20.7% of obsessive–compulsive symptoms in ultra high risk subjects.

Conclusion: Using a strict definition of obsessive–compulsive symptoms, we found relatively low prevalence rates of obsessive–compulsive symptoms and obsessive–compulsive disorder in patients with schizophrenia or related disorders; the rates are even lower than known rates of obsessive–compulsive symptoms and obsessive–compulsive disorder in the general population. Obsessive–compulsive symptoms rates in ultra high risk subjects are comparable to those in the general population. Further investigation of the predictive validity of obsessive–compulsive symptoms in ultra high risk subjects for developing psychosis is needed. Obsessive–compulsive symptoms either develop prior, during or after the onset of first episode psychosis.
Engineering geological investigations of the Trishuli-Galchhi Hydroelectric Project
Authors: K.C. Jyoti Kumar
Published: November 2010

DOI: 10.3126/bdg.v13i0.3963Bulletin of the Department of Geology Vol.13 2010, pp.23-36
Challenges in HIV/AIDS prevention, care and treatment programme in India
Authors: Sogarwal R , Bachani D , Venkatesh S
Published: November 2010

This paper explores the pertinent challenges of Government’s HIV/AIDS prevention, care and treatment program in India. Study is mainly based on observations made during field visits, discussion during review meetings at various levels and during training programmes of various functionaries from April 2007-November 2009. The paper also takes into account the observations made on the conclusion of the Mid-term Review conducted by the Government of India in during July- December 2009 after completion of first 2.5 years of the 5-year plan of NACP-III. Additionally, interactions with key program managers involved in implementation and management of HIV/AIDS Program at the state, district and facility levels. Though numerous efforts have been made and continued by the Government and partners, HIV prevention, care and treatment services have not been able to reach to the most-at-risk population, specifically in the rural population. Socio-cultural and managerial issues are the key challenges reported by the most of the key implementers. There is an urgent need to address and strengthen the whole spectrum of health systems through a collaborative approach to achieve the millennium development goals of universal access to prevention, care and treatment services in India. DOI: 10.3126/saarctb.v7i1.3955SAARC J. TUBER. LUNG DIS. HIV/AIDS 2010 VII(1) 1-7
Awareness of mother to child HIV transmission among women attending antenatal clinic, SMIMER, Surat
Authors: Patel PB , Nayak S
Published: November 2010

The study was conducted among 946 women attending antenatal clinic in SMIMER teaching hospital during 2008 to know their awareness regarding various aspects of mother-to-child transmission (MTCT) of HIV and it was found that though the general awareness of HIV is high, awareness of MTCT and its prevention is low which need to be improved through focused IEC campaign. Background : More than 90% of HIV infections in children aged <15 years are due to mother-to-child transmission (MTCT). The MTCT may reverse the gains of the child survival strategy in the country. Awareness of HIV and MTCT among antenatal women plays crucial role in preventing MTCT. Objective : To evaluate the awareness and knowledge of HIV/AIDS, MTCT of HIV and the methods to prevent MTCT of HIV. Methods : This is a descriptive cross sectional study carried out among antenatal women at the SMIMER Teaching Hospital during 2008. Results : Out of 946 women interviewed, 78% had heard of HIV/AIDS and main sources of information were television (48.8%) and radio (37.8%). Ninety-one percent of women were aware of MTCT of HIV. Trans-placental route (41%) was the commonly identified route of transmission. Awareness of HIV/AIDS, HIV co-existence with pregnancy and Mother to child transmission was significantly higher among women with at least secondary education (P<0.05). The level of knowledge and perceptions of MTCT of HIV is inadequate. Conclusion : There is an urgent need to scale up HIV awareness programme focusing on mother-to-child transmission in the region. Keywords: Awareness; education; mother-to-child transmission; prevention; HIV DOI: 10.3126/saarctb.v7i1.3956SAARC J. TUBER. LUNG DIS. HIV/AIDS 2010 VII(1) 8-12
Male circumcision should be promoted in developing countries as a major means of HIV prevention
Authors: Ali F , Vishal M
Published: November 2010

DOI: 10.3126/saarctb.v7i1.3958SAARC J. TUBER. LUNG DIS. HIV/AIDS 2010 VII(1) 19-21
Study of novel potassium permanganate staining in comparison with conventional ZN staining for the diagnosis of pulmonary tuberculosis
Authors: Banu A , Anand T
Published: November 2010

An estimated 1.8 billion individuals are infected worldwide with the Tuberculosis and there is one death due to it every 15 minutes. It is essential that a fast, effective and inexpensive diagnostic test for TB is developed as early diagnosis stands central to the control of the disease. Traditional diagnosis of tuberculosis is still dependent on sputum microscopy by ZN stain that requires expertise and lacks sensitivity. In this study, we tried to evaluate the use of potassium permanganate staining which is easy, inexpensive and does not require much expertise for screening. Potassium permanganate oxidises Mycolic acid present in cell wall of Mycobacterium sp. which evolves an identifiable oxidation pattern. This study was undertaken to investigate this property of potassium permanganate as a typical laboratory test bridging the gap between sensitivity and time restraint required for an early diagnosis of tuberculosis. The sputum samples (early morning – spot) were collected from patients. From each sample two slides were prepared; one was stained with ZN stain and other with modified potassium permanganate staining. Sputum samples were simultaneously cultured on LJ media after decontamination and concentration. The pattern evolved on staining with potassium permanganate was observed under light microscope and assessed as a diagnostic tool. We found that the pattern formed on oxidation was in association with the AFB status of the sputum (p= 0.0001). Keywords: Acid-Fast bacilli; Mycolic acid; Potassium permanganate oxidation.     DOI: 10.3126/saarctb.v7i1.3959SAARC J. TUBER. LUNG DIS. HIV/AIDS 2010 VII(1) 22-25
Evaluation of Nitrate Reductase Assay (NRA) for rapid detection of druc resistant tuberculosis at National Tuberculosis Centre, Nepal
Authors: Mandal PK , Basnyat S , Khadka DK , Bhatta DR
Published: November 2010

Background: Treatment of drug-resistant tuberculosis is often based on drug susceptibility testing results. Thus simple, rapid and economic test is very important for diagnosis of drug resistant tuberculosis and such method aids in TB control effectively. One such method is a Nitrate Reductase Assay (NRA). Objective: To evaluate feasibility and performance of Nitrate Reductase Assay in the screening of drug-resistant tuberculosis. Setting: National Tuberculosis Centre and SAARC TB and HIV/AIDS Centre, Thimi, Bhaktapur, Nepal from April 2008 to March 2009. Methods: A prospective study comparing the sensitivity and specificity of the Nitrate Reductase Assay with the gold standard Lowenstein Jensen proportion method in determining drug susceptibility pattern to four primary anti-tubercular drugs i.e. isoniazid, rifampicin, streptomycin and ethambutal among clinical isolates.Results: Among 121 specimens , the sensitivity and specificity of the Nitrate Reductase Assay for detection of Isoniazid resistance was 100% and 91%, for rifampicin was 100% and 98.95%, for streptomycin was 96% and 91.66% and for ethambutal was 100% and 98% respectively.Conclusions: The Nitrate Reductase Assay is sensitive and specific enough for the detection of drug resistant tuberculosis. It is rapid, easy to use and inexpensive, making it suitable for developing countries. Its usefulness for national drug resistance surveys should be assessed. Keywords: diagnosis; drug resistance; sensitivity; specificity; NRADOI: 10.3126/saarctb.v7i1.3960SAARC J. TUBER. LUNG DIS. HIV/AIDS 2010 VII(1) 26-30
Climatic and glaciological information inferred from air-content measurements of a Law Dome (East Antarctica) ice core
Authors: Delmotte Marc , Raynaud Dominique , Morgan Vin , Jouzel Jean
Published: November 2010

The total air content (V) of ice has been measured along the Dome Summit South (DSS) core from Law Dome, East Antarctica. The main features of this record are the very well-preserved sub-annual fluctuations of V (down to at least 900 m depth) and the significant increase of the V values during the last deglaciation. The sub-annual variations reflect changes in close-off porosity, and we interpret the V seasonal peaks as tracers of depth-hoar layers. For the longer time-scale, the large V fluctuations observed are interpreted in terms of elevation and/or close-off porosity changes under different assumptions. We analyze the possible influence of a different global pressure field and/or a change in seasonal temperature and precipitation cycles during the last glacial period. Our estimates of surface elevation changes derived from the V data are then compared with independent reconstructions of past elevations.
Avalanche risk mapping by simulation
Authors: Keylock Christopher J. , McClung David M. , Magnússon Magnús Már
Published: November 2010

In this paper we present a simulation approach to mapping avalanche risk with
application to settlements in Iceland. Two simulation models are developed to
calculate the probability of avalanches travelling a certain distance, and of
the flow being a specific width. These two simulation models, in combination
with knowledge of the average frequency of avalanche occurrence, the variability
in avalanche direction and the degree of loss caused by an avalanche, permit
risk values to be determined for the areas of concern.
Skier triggering, snow temperatures and the stability index for
dry-slab avalanche initiation
Authors: McClung D. M. , Schweizer Jürg
Published: November 2010

For more than 30 years the quantitative method of evaluating stability (e.g.
Roch, 1966; Föhn, 1987; Jamieson, 1995; Jamieson and Johnston, 1998a) has
been focused on calculation of a strength-to-load ratio (or stability index):
when the shear stress applied to the weak layer reaches the shear strength,
failure is imminent. However, field observations combined with experience and
measurements indicate that snow-slab temperatures and slab hardness can have a
strong influence on dry-snow slab stability. In this paper, we present a simple
static analysis of the stability index, and discuss the importance of slab
temperatures and hardness and macroscopic size effects (factors not contained in
the stability index) on snow-slab stability. Our conclusion is that the
traditional method lacks some elements which are very important in snow-slab
stability, particularly when skier triggering is involved.
Below-surface ice melt on the coastal Antarctic ice
sheet
Authors: Liston Glen E. , Winther Jan-Gunnar , Bruland Oddbjørn , Elvehøy Hallgeir , Sand Knut
Published: November 2010

In the Jutulgryta area of Dronning Maud Land, Antarctica, subsurface melting of
the ice sheet has been observed. The melting takes place during the summer
months in blue-ice areas under conditions of below-freezing air and surface
temperatures. Adjacent snow-covered regions, having the same meteorological and
climatic conditions, experience little or no subsurface melting. To help explain
and understand the observed melt-rate differences in the blue-ice and
snow-covered areas, a physically based numerical model of the coupled
atmosphere, radiation, snow and blue-ice system has been developed. The model
comprises a heat-transfer equation which includes a spectrally dependent
solar-radiation source term. The penetration of radiation into the snow and blue
ice depends on the solar-radiation spectrum, the surface albedo and the snow and
blue-ice grain-sizes and densities. In addition, the model uses a complete
surface energy balance to define the surface boundary conditions. It is run over
the full annual cycle, simulating temperature profiles and melting and freezing
quantities throughout the summer and winter seasons. The model is driven and
validated using field observations collected during the Norwegian Antarctic
Research Expedition (NARE) 1996–97. The simulations suggest that the
observed differences between subsurface snow and blue-ice melting can be
explained largely by radiative and heat-transfer interactions resulting from
differences in albedo, grain-size and density between the two mediums.
Statistical characteristics for the strain-dependent density and the spatial position for deformation-induced cracks in columnar-grain ice
Authors: Gold Lorne W.
Published: November 2010

Observations on the spatial distribution and on the strain dependence of the crack density are given for cracks formed during compressive, unidirectional, constant-strain-rate deformation of columnar-grain ice. Specimens, in the grain-size range of about 2 9 mm, were strained at the nominal rates of 10−3, 10−4 and 10−5 s−1 at 10°C. The axis of hexagonal crystallographic symmetry of each specimen grain tended to be in the plane perpendicular to the long direction of the grains and to have a random orientation in that plane. For stress applied perpendicular to the long direction of the grains, the deformation was practically two-dimensional. It was found that the log-normal distribution function provided a good approximation to the strain dependence of the crack density. Statistical characteristics of the distribution had a maximum in the same range of strain rate as found for the strength of columnar-grain ice. Analysis of the spatial distribution of the cracks indicated some deviation from randomness for specimens of grain-size less than 5 mm and total strain less than 50 × 10−4. The observations provide further evidence that crack formation under the experimental conditions is a random process.
Laboratory study of the migration of methane sulphonate in firn
Authors: Pasteur Elizabeth C. , Mulvaney Robert
Published: November 2010

Two 10 cm lengths of firn core from the Dyer Plateau (70°31 ′S, 65°01 ′W), Antarctic Peninsula, were used to carry out a laboratory experiment to investigate the migration of methane sulphonate, the anion of methane sulphonic acid (MSA), in natural firn. Each length was cut vertically into four pieces, and a dopant solution containing Cl−, NO3−, SO42−, F− and MSA− pipetted onto the top of three sections, the fourth being kept as a blank. The doped sections were stored vertically, with the doped end uppermost, for 8 months at a range of temperatures (nominally –5°, –10° and –22°C) before subsampling at 1 cm resolution and analysis by ion chromatography. The two firn lengths were treated identically and the results were consistent. Profiles of the doped firn sections showed that C1−, NO3 and SO42− remained in the uppermost subsample, although the NO3− concentrations were variable compared to the blank. The F− profile shows slightly elevated concentrations in the second sample down compared to the blank, at temperatures of -10°C and above. The MSA− showed higher concentrations in the second, third and fourth samples down at -10°C and above, which indicates that some percolated downwards from its original position at the top of the core. This experiment shows that MSA is mobile in warm firn even over a short period of time. We propose that the mechanism for the mobility of MSA− in natural firn is via liquid MSA drainage, though we cannot yet discount vapour phase transport.
Subglacial water-sheet floods, drumlins and ice-sheet
lobes
Authors: Shoemaker E.M.
Published: November 2010

The effect of subglacial lakes upon ice-sheet topography and the velocity
patterns of subglacial water-sheet floods is investigated. A subglacial lake in
the combined Michigan–Green Bay basin, Great Lakes, North America, leads
to: (1) an ice-sheet lobe in the lee of Lake Michigan; (2) a change in
orientations of flood velocities across the site of a supraglacial trough
aligned closely with Green Bay, in agreement with drumlin orientations; (3) low
water velocities in the lee of Lake Michigan where drumlins are absent; and (4)
drumlinization occurring in regions of predicted high water velocities. The
extraordinary divergence of drumlin orientations near Lake Ontario is explained
by the presence of subglacial lakes in the Ontario and Erie basins, along with
ice-sheet displacements of up to 30 km in eastern Lake Ontario. The megagrooves
on the islands in western Lake Erie are likely to be the product of the late
stage of a water-sheet flood when outflow from eastern Lake Ontario was dammed
by displaced ice and instead flowed westward along the Erie basin. The Finger
Lakes of northern New York state, northeastern U.S.A., occur in a region of
likely ice-sheet grounding where water sheets became channelized. Green Bay and
Grand Traverse Bay are probably the products of erosion along paths of strongly
convergent water-sheet flow.
Ice flow of Humboldt, Petermann and Ryder Gletscher, northern Greenland
Authors: Joughin Ian , Fahnestock Mark , Kwok Ron , Gogineni Prasad , Allen Chris
Published: November 2010

Radar interferometry, ice-penetrating radar profiles and an elevation model are used to determine the velocity fields, rates of ice discharge, approximate states of balance and catchment area for three large outlet glaciers in northeast Greenland. Discharge through flux gates is calculated for Humboldt and Petermann Gletscher, which are found to be in balance (at the level that the accumulation is known). A large difference between the measured and estimated fluxes for Ryder Gletscher may be a reflection of unsteady flow behavior for this glacier. The patterns of ice flow for the three glaciers considered are each unique, showing that the nature of ice discharge varies substantially from basin to basin, controlled by bed conditions and the presence of subglacial troughs and obstructions.
A Comparative Study of Two Folate-Conjugated Gold Nanoparticles for Cancer Nanotechnology Applications
Authors: Mansoori G. Ali , Brandenburg Kenneth S. , Shakeri-Zadeh Ali
Published: November 2010

We report a comparative study of synthesis, characteristics and in vitro tests of two folate-conjugated gold nanoparticles (AuNP) differing in linkers and AuNP sizes for selective targeting of folate-receptor positive cancerous cells. The linkers chosen were 4-aminothiophenol (4Atp) and 6-mercapto-1-hexanol (MH) with nanoconjugate products named Folate-4Atp-AuNP and Folate-MH-AuNP. We report the folate-receptor tissue distribution and its endocytosis for targeted nanotechnology. Comparison of the two nanoconjugates’ syntheses and characterization is also reported, including materials and methods of synthesis, UV-visible absorption spectroscopic measurements, Fourier Transform Infra Red (FTIR) measurements, Transmission electron microscopy (TEM) images and size distributions, X-ray diffraction data, elemental analyses and chemical stability comparison. In addition to the analytical characterization of the nanoconjugates, the cell lethality was measured in HeLa (high level of folate receptor expression) and MCF-7 (low level of folate receptor expression) cells. The nanoconjugates themselves, as well as the intense pulsed light (IPL) were not harmful to cell viability. However, upon stimulation of the folate targeted nanoconjugates with the IPL, ~98% cell killing was found in HeLa cells and only ~9% in MCF-7 cells after four hours incubation with the nanoconjugate. This demonstrates that folate targeting is effective in selecting for specific cell populations. Considering the various comparisons made, we conclude that Folate-4Atp-AuNP is superior to Folate-MH-AuNP for cancer therapy.
Programming Pluripotent Precursor Cells Derived from Xenopus Embryos to Generate Specific Tissues and Organs
Authors: Borchers Annette , Pieler Tomas
Published: November 2010

Xenopus embryos provide a rich source of pluripotent cells that can be differentiated into functional organs. Since the molecular principles of vertebrate organogenesis appear to be conserved between Xenopus and mammals, this system can provide useful guidelines for the directional manipulation of human embryonic stem cells. Pluripotent Xenopus cells can be easily isolated from the animal pole of blastula stage Xenopus embryos. These so called “animal cap” cells represent prospective ectodermal cells, but give rise to endodermal, mesodermal and neuro-ectodermal derivatives if treated with the appropriate factors. These factors include evolutionary conserved modulators of the key developmental signal transduction pathways that can be supplied either by mRNA microinjection or direct application of recombinant proteins. This relatively simple system has added to our understanding of pancreas, liver, kidney, eye and heart development. In particular, recent studies have used animal cap cells to generate ectopic eyes and hearts, setting the stage for future work aimed at programming pluripotent cells for regenerative medicine.
Optimization of the Culture Medium Composition to Improve the Production of Hyoscyamine in Elicited Datura stramonium L. Hairy Roots Using the Response Surface Methodology (RSM)
Authors: Amdoun Ryad , Khelifi Lakhdar , Khelifi-Slaoui Majda , Amroune Samia , Asch Mark , Assaf-Ducrocq Corinne , Gontier Eric
Published: November 2010

Traditionally, optimization in biological analyses has been carried out by monitoring the influence of one factor at a time; this technique is called one‑variable‑at‑a‑time. The disadvantage of this technique is that it does not include any interactive effects among the variables studied and requires a large number of experiments. Therefore, in recent years, the Response Surface Methodology (RSM) has become the most popular optimization method. It is an effective mathematical and statistical technique which has been widely used in optimization studies with minimal experimental trials where interactive factors may be involved. This present study follows on from our previous work, where RSM was used to optimize the B5 medium composition in [NO3−], [Ca2+] and sucrose to attain the best production of hyoscyamine (HS) from the hairy roots (HRs) of Datura stramonium elicited by Jasmonic Acid (JA). The present paper focuses on the use of the RSM in biological studies, such as plant material, to establish a predictive model with the planning of experiments, analysis of the model, diagnostics and adjustment for the accuracy of the model. With the RSM, only 20 experiments were necessary to determine optimal concentrations. The model could be employed to carry out interpolations and predict the response to elicitation. Applying this model, the optimization of the HS level was 212.7% for the elicited HRs of Datura stramonium, cultured in B5-OP medium (optimized), in comparison with elicited HRs cultured in B5 medium (control). The optimal concentrations, under experimental conditions, were determined to be: 79.1 mM [NO3−], 11.4 mM [Ca2+] and 42.9 mg/L of sucrose.
The Pharmacokinetics of Raloxifene and Its Interaction with Apigenin in Rat
Authors: Chen Yan , Jia Xiaobin , Chen Jian , Wang Jinyan , Hu Ming
Published: November 2010

Purpose: Raloxifene is a selective estrogen receptor modulator which is structurally similar to tamoxifen. As flavonoids can interact with raloxifene in vitro, we evaluated the in vivo pharmacokinetics of raloxifene in rats when co-administered with apigenin. Methods: The pharmacokinetics of raloxifene in the absence or presence of apigenin was investigated in rats after different dosage regimens. The plasma concentrations before and after enzymatic hydrolysis were analyzed by HPLC, and the pharmacokinetic profiles of raloxifene administered alone and in combination with apigenin were compared. Results: Co-administration of apigenin with raloxifene in a 1:2 ratio by weight resulted in a 55% and 37% increase in the Cmax and AUC of intact raloxifene, respectively. When equal proportions of raloxifene and apigenin (1:1) were administered, the Cmax and AUC of intact raloxifene were increased by 173% and 97% respectively. This increase in intact raloxifene was not associated with an increase in total raloxifene (intact plus conjugated raloxifene) because AUC and Cmax of total raloxifene when administered alone or in combination with apigenin were found to be similar. The results indicated that apigenin inhibited the glucuronidation and sulfation of raloxifene in the intestine bringing about an increased bioavailability of the drug. Conclusions: The results showed that apigenin decreased the first-pass metabolism of raloxifene but did not increase its absorption from the gastrointestinal tract.
Process Monitoring Evaluation and Implementation for the Wood Abrasive Machining Process
Authors: Saloni Daniel E. , Lemaster Richard L. , Jackson Steven D.
Published: November 2010

Wood processing industries have continuously developed and improved technologies and processes to transform wood to obtain better final product quality and thus increase profits. Abrasive machining is one of the most important of these processes and therefore merits special attention and study. The objective of this work was to evaluate and demonstrate a process monitoring system for use in the abrasive machining of wood and wood based products. The system developed increases the life of the belt by detecting (using process monitoring sensors) and removing (by cleaning) the abrasive loading during the machining process. This study focused on abrasive belt machining processes and included substantial background work, which provided a solid base for understanding the behavior of the abrasive, and the different ways that the abrasive machining process can be monitored. In addition, the background research showed that abrasive belts can effectively be cleaned by the appropriate cleaning technique. The process monitoring system developed included acoustic emission sensors which tended to be sensitive to belt wear, as well as platen vibration, but not loading, and optical sensors which were sensitive to abrasive loading.
Using a Floating-Gate MOS Transistor as a Transducer in a MEMS Gas Sensing System
Authors: Reyes Barranca Mario Alfredo , Mendoza-Acevedo Salvador , Flores-Nava Luis M. , Avila-García Alejandro , Vazquez-Acosta E. N. , Moreno-Cadenas José Antonio , Casados-Cruz Gaspar
Published: November 2010

Floating-gate MOS transistors have been widely used in diverse analog and digital applications. One of these is as a charge sensitive device in sensors for pH measurement in solutions or using gates with metals like Pd or Pt for hydrogen sensing. Efforts are being made to monolithically integrate sensors together with controlling and signal processing electronics using standard technologies. This can be achieved with the demonstrated compatibility between available CMOS technology and MEMS technology. In this paper an in-depth analysis is done regarding the reliability of floating-gate MOS transistors when charge produced by a chemical reaction between metallic oxide thin films with either reducing or oxidizing gases is present. These chemical reactions need temperatures around 200 °C or higher to take place, so thermal insulation of the sensing area must be assured for appropriate operation of the electronics at room temperature. The operation principle of the proposal here presented is confirmed by connecting the gate of a conventional MOS transistor in series with a Fe2O3 layer. It is shown that an electrochemical potential is present on the ferrite layer when reacting with propane.
Design and Implementation of a GPS Guidance System for Agricultural Tractors Using Augmented Reality Technology
Authors: Santana-Fernández Javier , Gómez-Gil Jaime , Del-Pozo-San-Cirilo Laura
Published: November 2010

Current commercial tractor guidance systems present to the driver information to perform agricultural tasks in the best way. This information generally includes a treated zones map referenced to the tractor’s position. Unlike actual guidance systems where the tractor driver must mentally associate treated zone maps and the plot layout, this paper presents a guidance system that using Augmented Reality (AR) technology, allows the tractor driver to see the real plot though eye monitor glasses with the treated zones in a different color. The paper includes a description of the system hardware and software, a real test done with image captures seen by the tractor driver, and a discussion predicting that the historical evolution of guidance systems could involve the use of AR technology in the agricultural guidance and monitoring systems.
The Nested Structure of Cancer Symptoms
Authors: Bellala G. , Ganesan A. , Krishna R. , Saxman P. , Scott C. , Silveira M. , Given C. , Bhavnani S. K.
Published: November 2010

Objective: Although many cancer patients experience multiple concurrent symptoms, most studies have either focused on the analysis of single symptoms, or have used methods such as factor analysis that make a priori assumptions about how the data is structured. This article addresses both limitations by first visually exploring the data to identify patterns in the co-occurrence of multiple symptoms, and then using those insights to select and develop quantitative measures to analyze and validate the results.

Methods: We used networks to visualize how 665 cancer patients reported 18 symptoms, and then quantitatively analyzed the observed patterns using degree of symptom overlap between patients, degree of symptom clustering using network modularity, clustering of symptoms based on agglomerative hierarchical clustering, and degree of nestedness of the symptoms based on the most frequently co-occurring symptoms for different sizes of symptom sets. These results were validated by assessing the statistical significance of the quantitative measures through comparison with random networks of the same size and distribution.

Results: The cancer symptoms tended to co-occur in a nested structure, where there was a small set of symptoms that co-occurred in many patients, and progressively larger sets of symptoms that co-occurred among a few patients.

Conclusions: These results suggest that cancer symptoms co-occur in a nested pattern as opposed to distinct clusters, thereby demonstrating the value of exploratory network analyses to reveal complex relationships between patients and symptoms. The research also extends methods for exploring symptom co-occurrence, including methods for quantifying the degree of symptom overlap and for examining nested co-occurrence in co-occur-rence data. Finally, the analysis also suggested implications for the design of systems that assist in symptom assessment and management. The main limitation of the study was that only one dataset was considered, and future studies should attempt to replicate the results in new data.
Gelation or molecular recognition; is the bis-(α,β-dihydroxy ester)s motif an omnigelator?
Authors: Griffiths Peter C , Knight David W , Morgan Ian R , Ford Amy , Brown James , Davies Ben , Heenan Richard K , King Stephen M , Dalgliesh Robert M , Tomkinson John , Prescott Stuart , Schweins Ralf , Paul Alison
Published: November 2010

Understanding the gelation of liquids by low molecular weight solutes at low concentrations gives an insight into many molecular recognition phenomena and also offers a simple route to modifying the physical properties of the liquid. Bis-(α,β-dihydroxy ester)s are shown here to gel thermoreversibly a wide range of solvents, raising interesting questions as to the mechanism of gelation. At gelator concentrations of 5–50 mg ml−1, gels were successfully formed in acetone, ethanol/water mixtures, toluene, cyclohexane and chloroform (the latter, albeit at a higher gelator concentration). A range of neutron techniques – in particular small-angle neutron scattering (SANS) – have been employed to probe the structure of a selection of these gels. The universality of gelation in a range of solvent types suggests the gelation mechanism is a feature of the bis-(α,β-dihydroxy ester) motif, with SANS demonstrating the presence of regular structures in the 30–40 Å range. A correlation between the apparent rodlike character of the structures formed and the polarity of the solvent is evident. Preliminary spin-echo neutron scattering studies (SESANS) indicated the absence of any larger scale structures. Inelastic neutron spectroscopy (INS) studies demonstrated that the solvent is largely unaffected by gelation, but does reveal insights into the thermal history of the samples. Further neutron studies of this kind (particularly SESANS and INS) are warranted, and it is hoped that this work will stimulate others to pursue this line of research.
Prendre le pli des techniques
Authors: Latour Bruno
Published: November 2010

Résumé À partir de la notion de mode d’existence développée par Gilbert Simondon et surtout par Etienne Souriau, il est possible d’aborder la question de la technique sans se laisser arrêter par la présence excessive de l’un de ses résultats : les objets techniques. On peut alors essayer de définir le mode propre de la technique comme un mouvement, un projet, un plissage, une forme très particulière de transcendance, qui n’a pas reçu en philosophie le traitement que mérite son importance et son ubiquité. La notion d’instauration proposée par Souriau permet de reprendre à nouveau la question de la construction mais délivrée des ambiguïtés du constructivisme.
Ventriloquie, performativité et communication
Authors: Cooren François
Published: November 2010

Résumé Cet article introduit la notion de ventriloquie , conçue métaphoriquement comme le processus par lequel des interlocuteurs animent ou font parler des figures (le nom que les ventriloques utilisent pour parler des mannequins qu’ils manipulent), des figures qui sont elles-mêmes censées animer ces mêmes interlocuteurs en situation d’interaction. Ventriloquiser des figures (par exemple, des valeurs, des principes, des règles, des faits etc.), c’est se mettre à parler en leur nom et ainsi gagner en autorité en donnant du poids à son propos. Des phénomènes de pouvoir peuvent ainsi être identifiés dans l’interaction sans qu’il faille s’éloigner d’une approche performative et interactionniste du social.
De l'intuition au jugement : le rôle performatif des objets dans la conception publicitaire
Authors: Gaertner Laure
Published: November 2010

Résumé Pour comprendre le processus d’idéation en publicité, c’est-à-dire les modalités d’émergence des idées de campagnes, l’article interroge les appuis de cette activité à partir d’une enquête ethnographique dans une agence. Partant du principe que les individus comme les choses sont dotés d’une agentivité potentielle dans l’action, nous étudions en particulier le rôle performatif des choses dans la création publicitaire. Il apparaît que les objets peuvent être porteurs d’intuitions, mises à l’épreuve dans des conversations ou dans des dialogues intérieurs où d’autres types d’objets performent à leur tour l’activité. Le processus d’idéation est fait d’interactions entre individus, représentations, conventions et différents types d’objets, et se déploie dans une dynamique temporelle circulaire.
Performativité de l'écrit et travail de maintenance
Authors: Denis Jérôme , Pontille David
Published: November 2010

Résumé L’analyse sociologique des objets graphiques qui ordonnent l’environnement se concentre généralement sur les ajustements effectués pour les constituer en ressources pour l’action, faisant des usages le principal ressort de leur performativité. À partir du cas de la signalétique du métro, cet article renverse cette perspective et se focalise sur l’activité d’aménagement des lieux. Il cherche ainsi à éviter de considérer les artefacts graphiques comme des objets inertes, et de faire de l’immuabilité une propriété intrinsèque de l’écrit. Il montre au contraire l’importance cruciale du travail de maintenance qui entretient au jour le jour les qualités spatiales et matérielles des objets et leur assure une force performative sans cesse réactualisée.