Frequency- domain multiuser detection for highly overloaded DS-CDMA systems

A DS-CDMA (Direct Sequence-Coded Division Multiple Access) system has maximum spectral efficiency if the system is fully loaded (i.e., the number of users is equal to the spreading factor) and we employ signals with bandwidth equal to the chip rate. However, due to implementation constraints we need to employ signals with higher bandwidth, decreasing the system’s spectral efficiency. In this paper we consider prefixassisted DS-CDMA systems with bandwidth that can be significantly above the chip rate. To allow high spectral efficiency we consider highly overloaded systems where the number of users can be twice the spreading factor or even more. To cope with the strong interference levels we present an iterative frequencydomain receiver that takes full advantage of the total bandwidth of the transmitted signals. Our performance results show that the proposed receiver can have excellent performance, even for highly overloaded systems. Moreover, the overall system performance can be close to the maximum theoretical spectral efficiency, even with transmitted signals that have bandwidth significantly above the chip rate.

Marriage and gender inequality: work–family arrangements of Portuguese and British highly qualified women

This article examines work–family reconciliation processes in order to understand if, over the course of marital life, women become socially closer or further away from their partner. Drawing on work–life interviews with highly qualified women in Portugal and Britain, we compare these processes in two societies with different historical and social backgrounds. Findings reveal three main configurations of social (in)equality which emerge during married life: growing inequality in favour of the man, in favour of the woman or equality between spouses. With due attention to the importance of national specific factors, we present three main conclusions. First, (in) equality is built up over the course of marital life and female strategies for reconciling family and work are at the core of this process. Second, the national specificities can mould the effects of cross-national gender mechanisms. Third, the intersection between cross-cultural phenomena such as conservative attitudes towards domestic work and national specificities (such as the availability of part-time options) is a rather complex process which needs further research.

中国四个城市吸引海外回流人才比较研究：一个政策的视角 (Returned highly skilled migrants in four Chinese cities: a policy perspective)

Most studies of returned highly skilled migrants in China were guided by a national approach, emphasizing how the size and direction of the return migration were shaped by national policies and practices. What have been overlooked are the flows of returned skills at the municipal level where talent attraction and employment really take place. To fill this gap, the author conducted a comparative study of the returned highly-skilled migration in Beijing, Shanghai, Guangzhou and Shenzhen, the four most important cities in China. Based on in-depth interviews with returned skills from different countries and with various occupational backgrounds, complemented by the analysis of talent policies that have been issued by each city since the early 1990s and relevant statistical data, this study finds that, first, municipal cities tend to make ‘localized policies’ in order to suit local situation and to increase flexibility and efficiency in their effort of enticing of talents, demonstrating a wide range of variations not yet discussed in previous literature. It is thus crucial to pay timely attention to municipalities in order to obtain a more accurate and balanced picture of returned skilled migration in China. Second, the flow of returned skills shall be perceived in a broader analytical framework, in which the attractiveness to skills comes mostly from the long-term career potentials made possible by the industrial structure of individual city and mediated by social, cultural and geographical factors. It is only within this larger framework and through the interaction with other factors that government policies play their modulator roles.

Next-generation sequencing is highly sensitive for the detection of beta-catenin mutations in desmoid-type fibromatoses

Desmoid-type fibromatoses are locally aggressive and frequently recurrent tumours, and an accurate diagnosis is essential for patient management. The majority of sporadic lesions harbour beta-catenin (CTNNB1) mutations. We used next-generation sequencing to detect CTNNB1 mutations and to compare the sensitivity and specificity of next-generation sequencing with currently employed mutation detection techniques: mutation-specific restriction enzyme digestion and polymerase chain reaction amplification. DNA was extracted from formalin-fixed paraffin-embedded needle biopsy or resection tissue sections from 144 patients with sporadic desmoid-type fibromatoses, four patients with syndrome-related desmoid-type fibromatoses and 11 morphological mimics. Two primer pairs were designed for CTNNB1 mutation hotspots. Using ≥10 ng of DNA, libraries were generated by Fluidigm and sequenced on the Ion Torrent Personal Genome Machine. Next-generation sequencing had a sensitivity of 92.36 % (133/144, 95 % CIs: 86.74 to 96.12 %) and a specificity of 100 % for the detection of CTNNB1 mutations in desmoid-type fibromatoses-like spindle cell lesions. All mutations detected by mutation-specific restriction enzyme digestion were identified by next-generation sequencing. Next-generation sequencing identified additional mutations in 11 tumours that were not detected by mutation-specific restriction enzyme digestion, two of which have not been previously described. Next-generation sequencing is highly sensitive for the detection of CTNNB1 mutations. This multiplex assay has the advantage of detecting additional mutations compared to those detected by mutation-specific restriction enzyme digestion (sensitivity 82.41 %). The technology requires minimal DNA and is time- and cost-efficient.

Mutational analysis of the highly conserved arginine within the Glu/Asp-Arg-Tyr motif of the alpha(1b)-adrenergic receptor: effects on receptor isomerization and activation.

We have suggested previously that both the negatively and positively charged residues of the highly conserved Glu/Asp-Arg-Tyr (E/DRY) motif play an important role in the activation process of the alpha(1b)-adreneric receptor (AR). In this study, R143 of the E/DRY sequence in the alpha(1b)-AR was mutated into several amino acids (Lys, His, Glu, Asp, Ala, Asn, and Ile). The charge-conserving mutation of R143 into lysine not only preserved the maximal agonist-induced response of the alpha(1b)-AR, but it also conferred high degree of constitutive activity to the receptor. Both basal and agonist-induced phosphorylation levels were significantly increased for the R143K mutant compared with those of the wild-type receptor. Other substitutions of R143 resulted in receptor mutants with either a small increase in constitutive activity (R143H and R143D), impairment (R143H, R143D), or complete loss of receptor-mediated response (R143E, R143A, R143N, R143I). The R413E mutant displayed a small, but significant increase in basal phosphorylation despite being severely impaired in receptor-mediated response. Interestingly, all the arginine mutants displayed increased affinity for agonist binding compared with the wild-type alpha(1b)-AR. A correlation was found between the extent of the affinity shift and the intrinsic activity of the agonists. The analysis of the receptor mutants using the allosteric ternary complex model in conjunction with the results of molecular dynamics simulations on the receptor models support the hypothesis that mutations of R143 can drive the isomerization of the alpha(1b)-AR into different states, highlighting the crucial role of this residue in the activation process of the receptor.

Oximetry alone versus portable polygraphy for sleep apnea screening before bariatric surgery.

BACKGROUND: Screening for obstructive sleep apnea (OSA) is recommended as part of the preoperative assessment of obese patients scheduled for bariatric surgery. The objective of this study was to compare the sensitivity of oximetry alone versus portable polygraphy in the preoperative screening for OSA. METHODS: Polygraphy (type III portable monitor) and oximetry data recorded as part of the preoperative assessment before bariatric surgery from 68 consecutive patients were reviewed. We compared the sensitivity of 3% or 4% desaturation index (oximetry alone) with the apnea-hypopnea index (AHI; polygraphy) to diagnose OSA and classify the patients as normal (<10 events per hour), mild to moderate (10-30 events per hour), or severe (>30 events per hour). RESULTS: Using AHI, the prevalence of OSA (AHI > 10 per hour) was 57.4%: 16.2% of the patients were classified as severe, 41.2% as mild to moderate, and 42.6% as normal. Using 3% desaturation index, 22.1% were classified as severe, 47.1% as mild to moderate, and 30.9% as normal. With 4% desaturation index, 17.6% were classified as severe, 32.4% as mild, and 50% as normal. Overall, 3% desaturation index compared to AHI yielded a 95% negative predictive value to rule out OSA (AHI > 10 per hour) and a 100% sensitivity (0.73 positive predictive value) to detect severe OSA (AHI > 30 per hour). CONCLUSIONS: Using oximetry with 3% desaturation index as a screening tool for OSA could allow us to rule out significant OSA in almost a third of the patients and to detect patients with severe OSA. This cheap and widely available technique could accelerate preoperative work-up of these patients.

Liprin (beta)1 is highly expressed in lymphatic vasculature and is important for lymphatic vessel integrity.

The lymphatic vasculature is important for the regulation of tissue fluid homeostasis, immune response, and lipid absorption, and the development of in vitro models should allow for a better understanding of the mechanisms regulating lymphatic vascular growth, repair, and function. Here we report isolation and characterization of lymphatic endothelial cells from human intestine and show that intestinal lymphatic endothelial cells have a related but distinct gene expression profile from human dermal lymphatic endothelial cells. Furthermore, we identify liprin beta1, a member of the family of LAR transmembrane tyrosine phosphatase-interacting proteins, as highly expressed in intestinal lymphatic endothelial cells in vitro and lymphatic vasculature in vivo, and show that it plays an important role in the maintenance of lymphatic vessel integrity in Xenopus tadpoles.

Early processing in the human lateral occipital complex is highly responsive to illusory contours but not to salient regions.

Human electrophysiological studies support a model whereby sensitivity to so-called illusory contour stimuli is first seen within the lateral occipital complex. A challenge to this model posits that the lateral occipital complex is a general site for crude region-based segmentation, based on findings of equivalent hemodynamic activations in the lateral occipital complex to illusory contour and so-called salient region stimuli, a stimulus class that lacks the classic bounding contours of illusory contours. Using high-density electrical mapping of visual evoked potentials, we show that early lateral occipital cortex activity is substantially stronger to illusory contour than to salient region stimuli, whereas later lateral occipital complex activity is stronger to salient region than to illusory contour stimuli. Our results suggest that equivalent hemodynamic activity to illusory contour and salient region stimuli probably reflects temporally integrated responses, a result of the poor temporal resolution of hemodynamic imaging. The temporal precision of visual evoked potentials is critical for establishing viable models of completion processes and visual scene analysis. We propose that crude spatial segmentation analyses, which are insensitive to illusory contours, occur first within dorsal visual regions, not the lateral occipital complex, and that initial illusory contour sensitivity is a function of the lateral occipital complex.

Daptomycin for highly resistant Enterococcus faecium infection.

We report a case series of 11 patients with severe E. faecium infections treated with daptomycin. All strains were resistant to ampicillin (MIC >8 mg/l), but susceptible to vancomycin. Seven out of 11 strains were also highly resistant to gentamicin (MIC >500 mg/l). All patients were treated with multiple broad-spectrum antibiotics prior to isolation of E. faecium and had severe underlying diseases. Our experience suggests that salvage therapy with daptomycin might be a safe and efficacious treatment for E. faecium infections.

A highly sensitive LC-tandem MS assay for the measurement in plasma and in urine of salbutamol administered by nebulization during mechanical ventilation in healthy volunteers.

The new-generation nebulizers are commonly used for the administration of salbutamol in mechanically ventilated patients. The different modes of administration and new devices have not been compared. We developed a liquid chromatography-tandem mass spectrometry method for the determination of concentrations as low as 0.05 ng/mL of salbutamol, corresponding to the desired plasma concentration after inhalation. Salbutamol quantification was performed by reverse-phase HPLC. Analyte quantification was performed by electrospray ionization-triple quadrupole mass spectrometry using selected reaction monitoring detection ESI in the positive mode. The method was validated over concentrations ranging from 0.05 to 100 ng/mL in plasma and from 0.18 to 135 ng/mL in urine. The method is precise, with mean inter-day coefficient of variation (CV%) within 3.1-8.3% in plasma and 1.3-3.9% in urine, as well as accurate. The proposed method was found to reach the required sensitivity for the evaluation of different nebulizers as well as nebulization modes. The present assay was applied to examine whether salbutamol urine levels, normalized with the creatinine levels, correlated with the plasma concentrations. A suitable, convenient and noninvasive method of monitoring patients receiving salbutamol by mechanical ventilation could be implemented. Copyright © 2011 John Wiley & Sons, Ltd.

The nature of the highly artistic student in visual arts at secondary school /

This qualitative investigation examined the nature of 7 highly artistic visual arts students at 2 secondary schools in southcentral Ontario. Through interviews, questionnaires, observations, and artwork documents, this study attempted to understand these highly artistic students in terms of creativity, motivation, social and emotional perspectives, and cognitive processes. Data collection occuned over a 3-monlh period. and the data analysis program NVivo 7 was used for coding to develop themes and categories for organizing data. The findings of this study illustrate the significant place that \ isual arts can lake in the growth and development for the youth of today. Participants idcniificd dcxclopnig critical thinking and problem-solving skills, taking risks, and meeting challenges ilirouuh their engagement in the creative process. The transferability of these skills \\ as referenced to numerous aspects of their lives. By enhancing individual perspectives through the study of visual arts, their local and world connections were extended, and environmental and societal concerns evolved. In addition, the communicative opportunities that visual arts provided for these students in terms of personal expression provided emotional health and paths of personal discovery. Through the participants' production of artwork with the many stages this involves, combined with insight into their needs, the participants relayed miportant suggestions for programming enhancements and educational settmgs lor \ isiial arts classrooms. These suggestions are meaningful for educators and curriculum developers of the future.

An exploration of gifted and highly able adolescents' experiences with stress and coping /

This narrative case study explored gifted and highly able adolescents' experiences with stress and coping. Nine students, ages 13-18, at 2 independent schools in southern Ontario, participated. They completed the Adolescent Coping Scale (Frydenberg & Lewis, 1993), and I generated individualized graphs of coping strategies. Participants talked about experiences they perceived as stressful in their academic, personal, social, and familial settings during a 60-90 minute one-on-one audiotaped interview. During the interview, each participant made observations about their own coping strategies profile. The interview was analyzed to identify stressor and coping themes. Participants completed a writing or art task to record perceptions of stress and coping. The 3 data sources were used to craft 9 individual story portraits, from which 5 main stressor themes emerged: issues of time; relationships, emotions, and communication; ethical, moral, and spiritual issues; global issues; and silences, or stressors not talked about in depth. Coping themes were: seeking relaxing activities; having positive attitudes and making wise choices; maintaining relationships with peers and family; understanding the role of faith and moral beliefs; having a supportive environment; knowing your own personality type; being aware of negative coping strategies; and keeping busy and avoiding stressfiil issues. The narratives are important because they present teenagers talking about their socioemotional worlds. The present findings provide empirical groundwork for curriculum development in affective education and highlight the importance of socioemotional development for future research in the area of giftedness and adolescence.

Défis technologiques et pédagogiques rencontrés par des enseignants lors de la mise en place d'un "projet portable" dans une école primaire de milieu défavorisé

Depuis la dernière décennie, les outils technologiques et informatiques ont connu un essor considérable dans plusieurs sphères d’activité de la société. L’éducation n’y a pas échappé, et le ministère de l’Éducation, du Loisir et du Sport (MELS) en a d’ailleurs fait une compétence transversale dans le cadre du Programme de formation de l’école québécoise. L’intégration des TIC s’est faite à travers différents moyens, à commencer par les laboratoires informatiques, les ordinateurs à même la salle de classe et, plus récemment, par l’introduction de projets portables où chaque élève et l’enseignant disposent de leur propre ordinateur. Afin d’être mené à terme, ce projet de recherche a été inscrit dans un projet à plus grande échelle, soit celui d’une recherche financée par le Conseil de recherches en sciences humaines du Canada (CRSH), qui a pour objectif d'analyser les obstacles auxquels font face les enseignants dans l'intégration des technologies à l'école. Le présent projet s'est quant à lui attardé plus spécifiquement aux défis technologiques et pédagogiques inhérents aux projets portables. L’étude s'est déroulée en milieu défavorisé, dans une école primaire montréalaise. Une telle intégration demande une planification rigoureuse et un suivi continu afin d’assurer le succès du projet. De plus, il est évident que ce type de projet pose aussi des défis technologiques et pédagogiques particuliers pour les enseignants. À ce sujet, trois catégories de facteurs qui peuvent avoir un impact sur la réussite des projets portables ont été relevées, soit : les facteurs personnels (internes à l’enseignant), les facteurs relatifs au travail (contexte d'enseignement, pratiques pédagogiques, etc.), ainsi que les facteurs relatifs au matériel et à l’infrastructure. À l’intérieur de ce mémoire, différents concepts, dimensions et indicateurs sont donc explicités et mis en relation afin de mieux comprendre les défis technologiques et pédagogiques qui peuvent survenir dans le cadre de la mise en oeuvre de projets portables. Trois enseignantes rattachées à autant de groupes d’élèves ont accepté de participer à une entrevue individuelle et de répondre à un questionnaire. Les échanges par courriel ont aussi été analysés. L'ensemble des données recueillies ont fait l'objet d'analyses qualitatives. Les analyses ont montré que la catégorie de facteurs citée la plus fréquemment était celle des facteurs relatifs au travail avec une forte majorité. Des défis ont toutefois été identifiés pour toutes les dimensions.