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Background and objectives Foetal and neonatal alloimmune thrombocytopenia (FNAIT) is studied mainly in Caucasian populations. Severe thrombocytopenia ( 9 /L) gives risk of haemorrhage and the most feared complication is intracranial haemorrhage (ICH). In Caucasian populations anti-human platelet antigen (HPA)-1a antibodies are the cause of FNAIT in >80% of the cases. The aims of this project were to study the gene frequencies of HPA-1-5 and 15 alleles in an Egyptian population (Arabic), and to determine the frequency of HPA-1a and -5b immunisations in a cohort of Egyptian pregnant women. Materials and methods Altogether 6974 pregnant women were included in the study. Genotyping was performed by polymerase chain reaction and antibodies were detected by flow cytometry and enzyme-linked immunosorbent assay. HPA-1-5 and 15 alleles were studied in 367 individuals. Results The HPA genotypes differed from genotypes published from different Caucasian and Chinese (Han) populations in HPA-1, -2, -3, and -5 systems with significant higher frequency of HPA-1b, -2b and -5b. The rate of HPA-1a alloimmunisation was found comparable to Caucasian populations. Severe thrombocytopenia was found in two newborns. No bleeding complication was reported. Anti-HPA-5b antibodies were detected in 4.4% of the pregnant women. Clinical consequences of these antibodies were not studied. Conclusion The HPA-1bb and -5bb genotypes are more frequent in the Egyptian Arabic population studied compared to Caucasian populations. FNAIT due to anti-HPA-1a and -5b antibodies must be suspected in cases of neonatal thrombocytopenia. Further large prospective studies are needed to increase the knowledge of clinical complications related to HPA alloantibodies in populations with different genetic backgrounds.

Conventional surface plasmon resonance (SPR) fiber sensors show selective behavior when resonance wavelengths are tuned to absorption peaks of the surrounding medium, as it is experimentally shown and evaluated in this paper by using a doubly-deposited uniform-waist tapered optical fiber (DLUWT) and a dye as a test material. This behavior is clearly distinguishable from the usual response to nonabsorbing media and can be used to develop a new concept of SPR transducers. At the same time, the obtained results, which are in accordance with the theoretical predictions permit to increase the basic knowledge on surface plasma waves excitation in optical fibers.

The synergistic effect between Co//Mo and Co//W stacked bed systems in the hydrodesulphurization (HDS) of 4,6-dimethyldibenzothiophene (4,6-DMDBT) was studied. The reaction was carried out in a high-pressure continuous-flow microreactor at 3 MPa and 300 °C. The observed synergism can only be explained by the action of hydrogen spillover (HSO). The selectivity in hydrogenation over direct desulphurization pathways (HYD/DDS) of Mo/γ-Al2O3 and W/γ-Al2O3 catalysts increased when the reaction was carried out in Co//Mo and Co//W stacked bed systems, respectively. The changes in selectivity can be explained by the fact that hydrogen spillover does not only create more active sites, but it also modifies the sites, favouring the HYD pathway. Differences in synergistic effect between Co//Mo and Co//W stacked bed systems were related to the higher degree of sulphurization of the molybdenum compared to the tungsten phase, as detected by XPS.

The international exchange of cord blood units (CBUs) for transplantation has brought new challenges to the stem cell donor registries involved in the exchange of BM and PBSCs. The unique properties of cord blood cells and differences in the search processes between CBUs and adult unrelated donors has required registries responsible for cord blood bank (CBB) networks to review their current practices and to develop new processes to accommodate for the provision of CBUs. This paper describes the aims and activities of the World Marrow Donor Association (WMDA) Cord Blood Working Group (CBWG) which was established in 2007 to gather and exchange information about cord blood registry needs and activities, and to develop guidelines to support and promote safe effective international exchange of unrelated CBUs for transplantation.

Our project for iGEM 2006 consisted of designing a cellular vanillin biosensor. We used an EnvZ -E. coli strain as a chassis, and constructed two different devices: a sensor and an actuator, assembled using OmpR-P as a standardised mediator. The sensor device contained a computation- ally designed vanillin receptor and a synthetic two-component signal transduction protein (Trz). The receptor protein was based on a ribose-binding protein as scaffold. The Trz was built by fusion of the periplasmic and transmembrane domains of a Trg protein with an EnvZ kinase domain. When the receptor complex binds Trg, an allosteric motion is propagated to the cyto- plasmic EnvZ kinase domain, resulting in autophosphorylation and subsequent phosphate transfer to the OmpR transcription factor, which finally induces transcription of the ompC promoter. As actuator, we used a synthetic transcriptional circuit, which implements an OmpR-P band detector having GFP and RFP as an output. We designed this circuit using a synthetic promoter working as an AND gate, which is synergistically activated by cI and CRP. Our constructed Trg-EnvZ fusion and AND promoter will be very useful to future synthetic biology projects. 1 Aims of the project The main goal of this project was to introduce students to synthetic biology through the iGEM competition (1), while trying to do an interesting project that could generate parts to be reused by many future projects in synthetic biology. We chose to design a cellular biosensor having vanillin as an input and the expression of two reporters as output. To perform this, we constructed two devices: a sensor (based on a receptor and a two-component signal transductor) and an actuator (which received the intermedi- ate signal and expressed the reporters). We used a phos- phorylation mechanism from EnvZ as transmembranal pathway using OmpR-P as a standardised mediator (Fig. 1). To avoid interference with the natural pathways and have a better control of the kinase/phosphatase domain, we chose an EnvZ - E. coli strain as a chassis. The receptor domain of the sensor was inspired on the work by the group of Dr Hellinga, in which a sensor of

In this work, we show the feasibility of using the evanescent field of a microfiber to excite the fluorescence of a fluorophore deposited on the surface of a polymer optical fiber. The fluorescence intensity gathered by the polymer optical fiber from the emitted on its surface has been measured for several gaps with the excitation fiber, showing a remarkable influence of the evanescent field at distances as high as 2.5mm. A further development of a device based on wrapping the microfiber around the polymer one has been measured, proving a more efficient fluorescence excitation.

The VISTA Variables in the Via Lactea (VVV) Survey is one of the six ESO public surveys currently ongoing at the VISTA telescope on Cerro Paranal, Chile. VVV uses near-IR ($ZYJHK_{\rm s}$) filters that at present provide photometry to a depth of $K_{\rm s} \sim 17.0$ mag in up to 36 epochs spanning over four years, and aim at discovering more than 10$^6$ variable sources as well as trace the structure of the Galactic bulge and part of the southern disk. A variability search was performed to find RR Lyrae variable stars. The low stellar density of the VVV tile $\textit{b201}$, which is centered at ($\ell, b$) $\sim$ ($-9^\circ, -9^\circ$), makes it suitable to search for variable stars. Previous studies have identified some RR Lyrae stars using optical bands that served to test our search procedure. The main goal is to measure the reddening, interstellar extinction, and distances of the RR Lyrae stars and to study their distribution on the Milky Way bulge. A total of 1.5 sq deg were analyzed, and we found 39 RR Lyrae stars, 27 of which belong to the ab-type and 12 to the c-type. Our analysis recovers all the previously identified RR Lyrae variables in the field and discovers 29 new RR Lyrae stars. The reddening and extinction toward all the RRab stars in this tile were derived, and distance estimations were obtained through the period--luminosity relation. Despite the limited amount of RR Lyrae stars studied, our results are consistent with a spheroidal or central distribution around $\sim 8.1$ and $\sim 8.5$ kpc. for either the Cardelli or Nishiyama extinction law.

Previous reports have shown an increased frequency of certain HLA antigens in association with erythema multiforme, including HLA-B15(B62), HLA-B35, HLA-A33, HLA-DR53 and, more recently, HLA-DQB1*0301. A strong association with HLA-DQ3 has been documented in patients with recurrent erythema multiforme. We have performed HLA typing in 39 patients with recurrent erythema multiforme, of whom 33 were associated with herpes simplex virus infection. The results were compared with 309 controls. In the recurrent erythema multiforme patients there was a statistically significant increase in HLA-B62 and HLA-B35. An increase in HLA-DR53 was also found, although this did not reach statistical significance. There was no increase in HLA-A33. The presence of HLA-DQ3 in the study population approached that in the controls. Finally, the study population demonstrated a trend towards a reduction in the HLA antigens A1, B8 and DR3. The study confirms the previously reported associations with HLA-B62 (B15), HLA-B35 and HLA-DR53. We have been unable to confirm an association of HLA-A33 or HLA-DQ3 with erythema multiforme. The HLA antigens A1, B8, and DR3 are associated with autoimmune disease, reflecting an increased host response to tissue self antigens. Their absence in patients with recurrent erythema multiforme (REM) may be an indicator of a poor host response to an antigen, which in the case of REM is the herpes simplex virus.

A fibre-optic sensor has been developed for the measurement of temperature, especially of liquids. The device is conceived as part of an all-optical CTD probe for the control of the physical parameters of a marine medium. The dependence on temperature of the optical properties (specifically, absorbance) of a thermochromic material, namely lophine (2,4,5-triphenylimidazole), is the basis of the sensor. The sensor presents some significant differences with respect to other similar sensors proposed in the literature: the use of adiabatic, long, tapered optical fibres with adjustable geometric parameters; the use of LED illumination in the 800 nm range; improvements in the deposition technique, etc. The sensors show a linear behaviour over the desired temperature range, and their sensitivity is high. Also, the dependence of the response of the sensor with variations of the geometry of the tapers is discussed. Specifically, we have performed measurements with different diameters of the taper waist, and we show the dependence of the slope of the response curve with that parameter.

Urinary samples from 20 kidney transplant recipients were studied to determine the cellular composition of the sediments using an immunocytological (IC) technique. The expression of HLA class I (A, B, C) and class II (DR, DQ, DP), CD2, CD3, CD4, CD8, and interleukin (IL)-2 receptor (IL-2R) on lymphocytes was assessed using a panel of monoclonal antibodies. The results were correlated with graft function and with the number of episodes of acute renal graft rejection (AR) during a period of 6 months posttransplantation. The cellular infiltration of lymphocytes (LC) and polymorphonuclear cells (PMNC) also was studied using a standard cytology (SC) technique. During this period, 17 of 30 episodes of graft dysfunction due to AR occurred in 12 patients: 8 to acute tubular necrosis (ATN) (n = 8); 4 to cyclosporine (CsA) toxicity (n = 4) and 1 to amphotericin toxicity (n = 1). The diagnosis of AR was made clinically by 3 independent observers, using biopsy in some cases. The immunocytology showed a significantly increased expression of HLA-DR, DO, and DP namely, greater than 20% positivity in 10% of samples on the tubular epithelial cells (TEC) of patients presenting with versus without AR (P < or =.001). In addition, a high correlation was observed between the expression of IL-2R and the presence of AR (p < or =.002). The standard cytology results showed a significantly increased percentage of LC and decreased percentage of PMNCs in samples obtained 2 days prior to the clinical manifestations of patients who developed AR (P =.001). A greater level of expression of antigen determinants was observed prior to AR. These results suggest that immunocytology of urinary sediments, which is a noninvasive technique, has enormous clinical potential for the differential diagnosis of AR, ATN, and CsA toxicity. In our study, the use of HLA class IL-specific monoclonal antibodies (Abs) gave a 100% specificity, 95% sensitivity, and 95% predictability. Although our results also indicate a potential value in the increased IL-2R expression, these findings must be confirmed by further studies. Furthermore, the combination of both immunologic and SC techniques in urinary sediments allows early detection of AR and is cost effective and simple features that could be used routinely for follow-up of renal transplant recipients.

A theoretical method for the study of surface plasmon excitation in metallic layers, as used in fiber-optics sensors, is presented. It is based in the calculation of the propagated fields in the waveguide structure and allows us to compute the loss of optical power in the fiber (which is the measured parameter) from energy conservation considerations. The agreement with experimental data obtained with real sensors is good. The method is conceptually simple and can be adapted to different configurations of the sensors.

Recent cross-sectional studies suggest an important role for transitional B lymphocytes (CD19 + CD24hiCD38hi) in promoting transplant tolerance, and protecting from late antibody-mediated rejection (ABMR). However, prospective studies are lacking. This study enrolled 73 de novo transplant recipients, and collected serial clinical, immunological and biochemical information over 48 ± 6 months. Cell phenotyping was conducted immediately prior to transplantation, and then on five occasions during the first year posttransplantation. When modeled as a time-dependent covariate, transitional B cell frequencies (but not total B cells or "regulatory" T cells) were associated with protection from acute rejection (any Banff grade; HR: 0.60; 95% CI: 0.37-0.95; p = 0.03). No association between transitional B cell proportions and either de novo donor-specific or nondonor-specific antibody (dnDSA; dnNDSA) formation was evident, although preserved transitional B cell proportions were associated with reduced rejection rates in those patients developing dnDSA. Three episodes of ABMR occurred, all in the context of nonadherence, and all associated with in vitro anti-HLA T cell responses in an ELISPOT assay (p = 0.008 versus antibody-positive patients not experiencing ABMR). This prospective study supports the potential relevance of transitional ("regulatory") B cells as a biomarker and therapeutic intervention in transplantation, and highlights relationships between humoral immunity, cellular immunity and nonadherence.

Mobile technology has been noted as a valuable resource for students in K-12 education and potentially for English Language Learners (ELL). ELL students enter schools with different levels of English proficiency and teaching such a population often presents a daunting academic challenge. Using mobile devices for learning, holds certain potentials as the literature indicates. Benefits of mobile technology such as flexibility, accessibility, interactivity, and motivation and engagement have been documented. This multiple-case study examines ELL teachers' use of the iPod touch in their instruction at elementary, middle, and high school levels to understand how such mobile devices are used and the teachers' perception of using them.

Molecular cloning techniques and V gene phage display have revolutionised the production of human monoclonal antibodies. Antibodies of a defined specificity can be obtained by selecting phage display libraries on antigen in a process known as panning. We have applied these techniques to the isolation of three HLA-A2-specific single chain variable domain fragments (scFv) from a patient alloimmunised by blood transfusion. Analysis of specificity with cells of HLA genotyped donors revealed the following: i) in addition to the major reactivity with HLA-A2, cross-reactivity with the HLA-A28 epitope; and ii) inhibition of scFv binding to the antigen by the patients' antibodies. The heavy chain variable genes of all three were derived from the germline gene Cos-3, carry the hallmarks of somatic hypermutation, and are most likely derived from clonally related B cells. The light chain variable domains were encoded by DPK1 and DPK8 from the VkappaI family. These data show that phage display can be used to clone HLA-specific alloantibodies that recognise the native antigen from alloimmunised patients.

ω Centauri is by far the most massive globular star cluster in the Milky Way, and possibly the remnant of a dwarf galaxy. As such, it contains a large number of variable stars of different classes. Here we report on an extensive, wide-field time-series study of ω Cen in the J and KS bands, which has allowed us to study the near-IR period-luminosity relations for different variability classes, including the first such relations for the SX Phoenicis stars.

The subfamily Stethaprioninae, a monophyletic group among characids, is almost unknown from the cytogenetic viewpoint. This paper shows the first chromosome characterization of Poptella paraguayensis, an endemic species of the Paraguay river basin. Analysis in Giemsa-stained preparations showed 2n=50 : 10 M+26SM+8ST+6A. The nucleolar organizing regions (NORs) detected by silver nitrate and GC-specific fluorochrome mithramycin (MM) staining showed two NOR-bearing chromosomes in the diploid complement. DA/DAPI staining showed no differential fluorescence along the chromosomes. C-banding evidenced small blocks of heterochromatin in the centromeric and telomeric regions. Phylogenetic relationships between the Stethaprioninae and other characids are discussed on the base of chromosome data.

Interactions involving the T-cell receptor (TCR) and major histocompatibility complex (MHC) are fundamental to the generation of a specific immune response. The study of interpopulation differences in TCR genes may identify those genes which are subject to selection, and also provides useful information for future genetic studies in these populations. In this study we present analysis of five TCRAV polymorphisms, for V5S1, V6S1, V8S1, V17S1, and V21S1 loci in five human populations by single-strand conformational polymorphism (SSCP) analysis. Caucasian, Chinese, Gambian, AfroCaribbean, and South American Indians (Mapuches) showed marked interpopulation variation for both the silent (V5S1, V17S1, and V21S1) and coding (V6S1 and V8S1) polymorphisms. In general the alleles were conserved in the different populations, but new, additional variants were found for V5S1 and V17S1 in Gambians and Caucasians. V6S1 overall showed the highest nucleotide diversity, and V6S1 genotype distributions were skewed away from expected values in Chinese and Mapuches. Analysis of allelic associations showed a general lack of linkage disequilibrium between the loci, which was reflected by the absence of strong population-specific haplotypes.

immunization in patients whohave been previously immunized by pregnan-cy or transfusion is not prevented. Neither canimmunization against platelet-specific al-loantigens be prevented by removing leuco-cytes from platelet concentrates, but platelet-specific antibodies seem to occur mainly inpatients who develop HLA class I antibodies.Not all patients with HLA antibodies are re-fractory. Often the antibodies only react witha small percentage of panel lymphocytes andthen most random donors are compatible.Furthermore, although there are individualdifferences, some HLA class I antigens areweakly expressed on platelets. Nevertheless,refractory alloimmunized patients in need ofplatelet transfusions will continue to occur.Opinions on the optimal management of suchpatients differ. Moreover, some simple and in-teresting new crossmatch techniques have re-cently been developed. For these reasons itseemed of interest to devote an InternationalForum to the subject.There seem to be two main approaches tothe management of refractory patients: (I) theselection of platelet concentrates based on theHLA class I phenotype and, or the specificityof the HLA (and platelet-specific) antibodies,and (II) the selection of platelet concentratesby crossmatching.To obtain more information on the sub-ject, the following questions were submittedto 15 experts in the field

Four species of Curimatidae, collected in lakes situated in the floodplain of the Miranda river (Pantanal-MS), were analyzed cytogenetically. Karyotypes of Curimatella dorsalis, sectrogaster curviventris and Steindachnerina brevipinna were characterized by 2n = 54 metacentric and submetacentric chromosomes, one pair of chromosomes bearing NORs in terminal position (46 M/8 SM and 13th, 42 M/12 SM and 20th, 48 M/6 SM and 17th, respectively). The first two species showed constitutive heterochromatin on the centromeric region of some chromosomes and in the other species heterochromatic blocks were observed on the centromeric and telomeric regions of a few chromosomes. The karyotype of Curimatopsis myersi showed 2n = 46 (42 M/4 SM), one pair bearing terminal NORs, representing the lowest diploid number for the family.

Participation in online courses has significantly increased in recent times. Student performance in online mathematics classes lag behind their counterparts in other subject areas. We hypothesize that one of the main reasons for this is the lack of technological tools for effective communication of mathematics via the Internet. We propose to test our hypothesis by implementing new technologies and evaluate the difference in course performance and attrition rates between the students who use these technologies and a control group.

In this work we experimentally show how the technology of surface plasmon resonance (SPR) in doubly deposited uniform- waist tapered optical fiber sensors (DLUWTs) can be extended into the visible region (around 520 nm) by changing the thicknesses of the deposited layers. In this way, by using DLUWTs we can cover, in an easy and versatile way, a total wavelength range over 1000 nm wide, having shown in the past how this same kind of sensors can be usable in the communication band. The possibilities of fiber sensors can then be applied to the region of visible wavelengths, which is very interesting from the biological point of view.

The basic principle of treatment in a massive blood loss is the bleeding site control and the volume loss replacement through blood transfusion. Transfusions have several drawbacks, for that reason perfluorocarbon emulsions (PFC) have been developed to replace the blood function of transport oxygen to tissues and maintain intravascular volume in case of hemorrhage. In addition, PFC emulsions must have physicochemical properties suitable to be compatible with the physiological medium. In order to know the emulsion properties and analyze their effects when it is used intravascularly, the emulsion was characterized evaluating the particle size distribution, rheological behavior, osmolality and pH over time.

While mobile devices have become very popular for communication and entertainment, there is a lack of research about how these devices can contribute in educational settings. This chapter describes an effort to use iPod touch devices as a teaching tool in middle school English Language Learner classes. The authors explore the affordances of the iPod touch as well as the challenges of implementing an iPod based project so as to gain a better understanding of the potentials offered by mobile devices for learning purposes. The authors report in this chapter their research from the perspective of the teachers and the instructional technologist involved with this project, and then discuss future plans based upon the findings.

1. SCA40 (0.1 nM-0.1 mM) produced concentration-dependent suppression of the spontaneous tone of human isolated bronchus (-log EC50 = 6.85 +/- 0.09; n = 10) and reached a maximal relaxation similar to that of theophylline (3 mM). The potency (-log EC50 values) of SCA40 compared to other relaxants was rolipram (7.44 +/- 0.12; n = 9) > SCA40 > or = levcromakalim (6.49 +/- 0.04; n = 6) > SKF94120 (5.87 +/- 0.10; n = 9). 2. When tested against the activity of the isoenzymes of cyclic nucleotide phosphodiesterase (PDE) isolated from human bronchus, SCA40 proved highly potent against PDE III (-log IC50 = 6.47 +/- 0.16; n = 4). It was markedly less potent against PDE IV (4.82 +/- 0.18; n = 4) and PDE V (4.32 +/- 0.11; n = 4). 3. Human polymorphonuclear leukocytes (PMNs) stimulated with N-formylmethionyl-leucyl-phenylalanine (FMLP) produced a concentration-dependent superoxide anion generation and elastase release. SCA40 (1 nM-10 microM) produced a concentration-related inhibition of FMLP (30 nM approximately EC50)-induced superoxide production (-log IC50 = 5.48 +/- 0.10; n = 6) and elastase release (-log IC50 = 5.50 +/- 0.26; n = 6). Rolipram was an effective inhibitor of superoxide generation and elastase release (-log IC50 values approximately 8) while SKF94120 and levcromakalim were scarcely effective. 4. FMLP (30 nM) and thimerosal (20 microM) induced leukotriene B4 production and elevation of intracellular calcium concentration in human PMNs. The production of leukotriene B4 was inhibited by SCA40 in a concentration-related manner (-log IC50 = 5.94 +/- 0.22; n = 6) but SCA40 was less effective against the elevation of intracellular calcium. Rolipram was an effective inhibitor of leukotriene B4 synthesis (-log IC50 approximately 7) and intracellular calcium elevation (-log IC50 approximately 6) while SKF94120 and levcromakalim were scarcely effective. 5. It is concluded that SCA40 is an effective inhibitor of the inherent tone of human isolated bronchus. The bronchodilatation produced by SCA40 appears mainly related to PDE inhibition since the potency of SCA40 as a relaxant of human isolated bronchus was found to be close to its potency as inhibitor of PDE III activity isolated from human bronchus. In addition, SCA40 exhibited inhibitory effects on human PMN function stimulated by FMLP. These effects may be related to the ability of SCA40 to inhibit PDE IV from human PMNs while the contribution of PDE V inhibition is uncertain. We found no evidence of a role for levcromakalim-sensitive plasmalemmal K+-channels in human PMNs.

This paper focuses on the relation between structure and rheology of flocculated suspensions. Rheological measurements were taken both in shear and nearly extensional flows. The structures of magnetic iron oxide suspensions were visualized using cryogenic scanning electron microscopy (Cryo-SEM) and video-enhanced light microscopy (VELM) under shear, elongational, and rotational flows. Shear fields were generated by using a miniature Couette geometry, whereas elongational and rotational fields were generated by an innovative technique, which takes advantage of a surface tension gradient on the interface of an air bubble, and were visualized in real time under a light microscope. In Couette flow, the particle networks formed at high concentrations (9.4% by volume) do not uniformly break up into smaller units of particles, as at lower concentrations, but rather break up at the center of the gap, segregating particles toward the walls. Real-time light microscopy observations of a spinning floc show that the deformation and breakup of flocs is a process that gradually occurs with time. In extensional flow, flocs elongate and break up, explaining the apparent extensional thinning behavior measured. Apparent extensional viscosities were one to two orders of magnitude larger than shear viscosities at the same applied stress.

It has been established that oligoclonal expansion is a common feature of the CD8+ T cell population, particularly within the CD8+ CD57+ lymphocyte subset. In addition, clonal malignancies involving CD8+ CD57+ T cells (large granulocytic lymphocytic leukemias) are often accompanied by rheumatoid arthritis, Felty's syndrome, or both. Therefore, to identify disease-related alterations in the CD8+ T cell repertoire, we have compared the patterns of oligoclonality in the CD8+ T cells of rheumatoid arthritis patients (n = 32) with those of age-matched controls (n = 25). By using a multiplex PCR assay for the CDR3 length of TCR beta-chains, we have found a striking increase in the frequency of CD8+ oligoclonality involving V beta 3 TCR: 50% of the rheumatoid arthritis patients had evidence of oligoclonality in this TCR family compared with 4% of controls (p < 0.0002). In addition, two unrelated RA patients had clonally dominant CD8+ T cell beta receptors that were identical in amino acid sequence, suggesting selection by a common Ag. An analysis of a subset of RA patients with mAbs specific for V beta 3 TCR revealed the presence of clonal expansion in a minority of patients usually, but not exclusively, involving the CD57+ subset. These data define a phenotype of the T cell repertoire that is strongly associated with rheumatoid arthritis; the mechanisms and genetic and environmental factors that explain this phenomenon remain to be defined.

A technique is proposed to extend the application of surface-plasmon-based spectroscopy into the mid-infrared spectral regime, which is of substantial interest in the field of chemical analysis and biosensing. Surface plasmons can be excited for wavelengths of the order of 6 μm at corrugated waveguides for a given combination of materials and thicknesses, and for refractive indices of the surrounding medium corresponding to those of organic solvents. This approach can easily be extrapolated to other values of any of these parameters. Based on these considerations, a new generation of mid-IR SPR sensors can be developed with a diverse range of potential applications in chem/bio sensing.

While the potential of social networking sites to contribute to educational endeavors is highlighted by researchers and practitioners alike, empirical evidence on the use of such sites for formal online learning is scant. To fill this gap in the literature, we present a case study of learners’ perspectives and experiences in an online course taught using the Elgg online social network. Findings from this study indicate that learners enjoyed and appreciated both the social learning experience afforded by the online social network and supported one another in their learning, enhancing their own and other students’ experiences. Conversely, results also indicate that students limited their participation to course-related and graded activities, exhibiting little use of social networking and sharing. Additionally, learners needed support in managing the expanded amount of information available to them and devised strategies and “workarounds” to manage their time and participation.

To assess the influence of environmental exposure to tobacco smoke on the nasal symptoms and nasal resistance of young patients with perennial allergic rhinitis.Cross-sectional study.Tertiary referral centre.Fifty patients were evaluated (aged 10-19 years old): 25 patients with and 25 patients without recent exposure to tobacco smoke (confirmed by cotinine/creatinine ratio).After a clinical evaluation, all the patients replied to a validated questionnaire of the severity of the nasal symptoms. Then total nasal airway resistance was recorded by active anterior rhinomanometry.Patients with exposure to tobacco smoke had a larger total resistance than patients without exposure (t-test, P0.01). No significant correlation was observed between the total score of the questionnaire of nasal symptoms and the nasal resistance.In young patients with perennial allergic rhinitis, exposure to tobacco smoke can be related to increased nasal resistance, which may not be recognised by the report of nasal symptoms.

A miniature fiber Bragg grating strain rosette is presented. The proposed design is made possible through the development of low curvature radius lossless tapers, thus offering advantages in miniaturization of the rosette configuration. We report on the experimental validation of the miniature rosette design, demonstrating its effective operation.

In this work, the performance of uniform-waist tapered optical fiber sensors based on SPR with Indium Nitride (InN) as dielectric layer has been experimentally studied. The obtained results show that the overall performance in terms of reliability, long term stability and sensitivity is improved. Furthermore, the dependence of the sensitivity with the thickness of the dielectric layer is also studied, showing that increases as the thickness decreases while the well known trend to excite the surface plasmons at longer wavelengths or higher refractive index of the outer medium is kept. Thus, a novel application of the InN to optical fiber sensors is demonstrated. The use of this material would be of great interest to produce new, improved, SPR-based devices for chemical and biological sensing.

In this work we present experimental results that confirm the influence of an absorptive surrounding medium in the behavior of conventional SPR fiber sensors. It can be observed that when a plasmon resonance coincides with a wavelength absorbed by the medium, the depth of the dip is affected, as predicted in the simulations. The results are important from the basic point of view, since the influence of absorptive medium in plasma waves has not been sufficiently studied up to date and they can also be used as the basis for a new method of SPR-based refractometry selective to specific analytes without the need of the addition of recognizing elements to the transducer.

We present the results of a chemical attack on the optical fiber surface previous to the deposition of the double layer (metal plus dielectric) in Double-layer uniform-waist tapered fibers (DLUWTs) used for the development of SPR sensors. It is shown how this simple chemical treatment increases the roughness of the surface and permits improvement of the stability of the deposits and the general performance of the sensors. The obtained devices are robust and very compact, their sensitivity is good and repeatability of the measurements is remarkably increased. The procedure can be useful for any fiber-optic sensor.

In this work, an Indium Nitride (InN) dielectric overlay has been used to develop a surface plasmon resonance optical fiber sensor. Although InN is a very promising material in electronics industry, this is the first time that this kind of material is used for optical sensing. The obtained results show an improvement of the reliability and long term stability with respect to previous devices made with the same technology. More remarkably, the sensitivity increases up to 11,800 nm/RIU in the range of outer refractive indices between 1.415 and 1.429, the highest sensitivity achieved with this kind of devices. Therefore, a novel application of the InN to optical fiber sensors is demonstrated. The use of this material would be of great interest to produce new SPR-based devices for chemical and biological sensing.

We show the settling behaviors of flocculated, magnetic and nonmagnetic iron oxide suspensions. It is unique, since in the literature on settling of model submicron flocculated particulate suspensions there is no direct visualization of the structures and how they change during settling. Channeling, cracking, and a novel collapse phenomenon were detected during settling. Causes were investigated using lapse videorecording for side and top views. The effect of air bubbles was shown to contribute to the accelerated settling of the suspension by creating channels that conduct oil to the settling front. Settling heights were recorded for long periods of time (up to a year) for iron oxide suspensions of different concentrations. Decreasing tube diameters delayed settling, and magnetic interparticle forces produced smaller final settling heights. The effect of magnetic forces was interpreted in terms of a floc model. The model find magnetic flocs 1.3 to 1.4 times denser than their nonmagnetic analogs. Finally, a mechanism is put forth to interpret the settling behavior observed

It is shown how the design possibilities offered by double-layer uniform-waist tapered optical fibers (DLUWTs) permit to move the wavelength detection range to adapt the response of the sensors to varied conditions. In particular, we have obtained very good experimental curves showing that we can achieve plasmon resonances in the C-band of the optical communications, around 1.5 μm, for the range of refractive indices of aqueous media, highly interesting in the biosensors field. Also, we show results for other interesting wavelength region, around 500 nm, where we can take advantage of the absorption peaks of the analytes. Finally, we explore the possibilities of using InN as a dielectric material for the second layer of the deposition. These results contribute to considerably expand the applicability and performance of SPR fiber sensors.

Experimental results are shown demonstrating that multiple surface plasma waves can be excited in optical fibres at the 1.5 μm optical communications region for the range of refractive indices of aqueous media using doubly deposited tapered fibre structures, well known to exhibit small or zero sensitivity to polarization. Well-defined plasmon dips were obtained with high sensitivity to the surrounding refractive index. This characteristic, together with the substantial flexibility for local and distributed measurement associated with optical fibre sensing supported by the C-Band technology, indicate that these devices can be very advantageously used for chemical, biological and environmental sensing.

The resonance of surface plasma waves in metallic layers is a strongly polarization-dependent phenomenon by the very nature of the physical effect responsible of that resonance. This implies the necessity of polarization-controlling elements to be added to any operative surface-plasmon-resonance-based sensor. A fully symmetrical, circular-section double deposition of a metallic and a dielectric layer on a uniform-waist tapered optical fiber (SymDL-UWT) permits us to completely eliminate the dependence on polarization of the plasmon excitation, with the corresponding operative advantages and basic theoretical consequences. We depict the fabrication process of these transducers, which is based on the use of a simple and efficient rotating element developed by us, and show the characteristics of the produced devices. No such device has been depicted up to date. As our experimental results show, this kind of devices can be considered a very good option for the development of simple, compact, and efficient chemical and biological sensors.

In this work a new configuration of a refractometric sensor for aqueous solutions based on the combination of surface plasmon resonance (SPR) with fibre Bragg gratings (FBG) is presented. Two FBGs are selected having reflection maxima in each side of the plasmon resonance peak. These FBGs enable a different processing scheme for the information provided by the SPR transducer. This improved interrogation method increases the sensitivity and resolution of the sensor compared with those obtained with the usual method of tracking the spectral transmittance minimum and makes the system performance independent of optical source power fluctuations. The experimental results obtained with a double-layer uniform-waist tapered fibre show the feasibility of this approach and its applicability in SPR-based biosensors that must face very exigent measuring conditions.

Suspensions consisting of particles of colloidal dimensions have been reported to form connected structures. When attractive forces act between particles in suspension they may flocculate and, depending on particle concentration, shear history and other parameters, flocs may build-up in a three-dimensional network which spans the suspension sample. In this paper a floc network model is introduced to interpret the elastic behavior of flocculated suspensions at small deformations. Elastic percolation concepts are used to explain the variation of the elastic modulus with concentration. Data taken from the suspension rheology literature, and new results with suspensions of magnetic γ-Fe2O3 and non-magnetic α-Fe2O3 particles in mineral oil are interpreted with the model proposed.

A new interrogation method based on Fibre Bragg Gratings (FBG) for Surface Plamon Resonance (SPR) sensors in the region of refractive indices of aqueous solutions is described. Two FBGs are selected with their Bragg wavelengths at opposite sides of the plasmon resonance peak. The response of the system can be made independent of the fluctuations of the optical power source, and the linearity and the sensitivity of the sensor are improved. The use of the spectral selectivity of gratings for the interrogation of SPR sensors in different configurations is also promising in terms of multiplexing, temperature referencing or multiparameter detection.