Range estimation in multicarrier systems in the presence of interference: Performance limits and optimal signal design

Cataloged from PDF version of article.Theoretical limits on time-of-arrival (equivalently, range) estimation are derived for multicarrier systems in the presence of interference. Specifically, closed-form expressions are obtained for Cramer-Rao bounds (CRBs) in various scenarios. In addition, based on CRB expressions, an optimal power allocation (or, spectrum shaping) strategy is proposed. This strategy considers the constraints not only from the sensed interference level but also from the regulatory emission mask. Numerical results are presented to illustrate the improvements achievable with the optimal power allocation scheme, and a maximum likelihood time-of-arrival estimation algorithm is studied to assess the effects of the proposed approach in practical estimators. © 2011 IEEE

Abordagem aos números decimais e suas operações: a importância de uma “eficaz navegação” entre representações

Este artigo foca alguns aspectos e ideias de tarefas a serem exploradas com os alunos relativamente à multiplicação de números decimais, discutindo o conhecimento matemático para o ensino subjacente à preparação e à aplicação de tais tarefas. Discutem-se algumas representações dessa multiplicação e a importância de um rico e fundamentado conhecimento matemático para o ensino como promotor de um conhecimento matemático com significado, por parte dos alunos, por via de uma eficaz navegação entre representações. A escolha das representações pretende, aqui, tornar também evidente o motivo pelo qual, ao multiplicar dois números decimais, o número de casas decimais do produto é a soma dos factores. O texto tem por base um trabalho colaborativo desenvolvido ao longo dos últimos anos com professores do 1º ciclo do ensino básico (alunos com idade entre seis e nove anos), tendo como ponto de partida as discussões ocorridas ali, as reflexões subjacentes e as maiores dificuldades sentidas tanto pelos alunos, como pelos próprios professores. É de salientar que o facto de se abordarem conjuntamente representações dos números em decimais e fraccionários possibilita que os alunos se consciencializem de diferentes representações para um mesmo valor, o mesmo ocorrendo quando se utilizam diversas quantidades como unidades discretas, ou distintos tipos de unidades. Apenas se o professor for detentor de um sustentado conhecimento matemático para o ensino ele poderá recorrer a essas distintas representações de maneira construtiva e de modo a que tenham significado para os alunos

Long-term consequences in survivors of critical illness. Analysis of incidence and risk factors

Aim. This study investigates the incidence of long-term consequences in survivors of critical illness 6 months after ICU care. A retrospective analysis of the risk factors was also completed.Methods. A mixed-method design was used. A qualitative design was used in the questionnaire study (phase 1), and a quantitative design was used for the retrospective study (phase 2).Results. 116 patients were interviewed. Forty-eight patients (41.4%) reported at least one long-term consequence 6 months after ICU discharge. The most frequent consequences were anxiety (n = 33, 28.4%), depression (n = 32, 27.6%) and chronic pain (n = 24, 20.7%). The interview showed the concurrent caseness of PTSD, anxiety and depression in 14 (12.1%) patients. Observed risk factors were age > 60 years (OR = 2.65, IC = 1.23-5.69; p = 0.0119), trauma diagnosis (OR = 5.3, IC = 1.60-17.76; p = 0.0033), length of mechanical ventilation > 7 days (OR = 2.18, IC = 1-4.74; p = 0.0471) length of ICU stay > 10 days (OR = 2.47, IC = 1.16-5.26; p = 0.0185) and clinical conditions at the ICU admission. The quality of life score was lower if the respondent had long-term consequences.Discussion. A high incidence of long-term consequences is found in survivors of critical illness. In future, studies that investigate interventions to prevent these issues after ICU care are need

The Association of Systemic Microvascular Changes with Lung Function and Lung Density: A Cross-Sectional Study

10.1371/journal.pone.0050224PLoS ONE712

The Time is Now!: Talking with Black Youth about College

This article explores the authors work with a group of African American youth in an after school community literacy program. The authors examine how these youth used a set of Internet-based technology tools to evaluate whether or not a group of colleges would affirm their cultural identity and help them succeed if they attended these institutions. From this work, the authors describe how they began to rethink the relationships between college exploration,access, cultural identity, and students potential academic success

Il Questionario «Experiences In Close Relationships» (Ecr) Per la Valutazione dell’attaccamento negli Adulti: Ampliamento Delle Evidenze di Validità per la Versione Italiana.

Objective Improvement in the assessment of adult attachment are mandatory, if research on attachment and psychopathology is to make substantial progress. In a preliminary study, the Italian version of the questionnaire ‘Experiences in Close Relationships’ (ECR) demonstrated good psychometric properties. We aimed at collecting further evidence of the validity of the questionnaire. Methods We included in the study subjects of 18-65 years, with at least junior high school degree. We examined convergent validity on 364 subjects, with the Relationship Questionnaire (RQ) as a criterion measure. In these subjects, we also compared three different Italian translations of item 21 with regard to factorial validity and internal consistency. Data from these subjects and other 386 subjects were used to compute norms for scale scores, stratified for age and gender. Results Internal consistency was satisfactory. Cronbach’s alpha was. 89 for both the ‘Anxiety’ and ‘Avoidance’ scales. A new Italian version of item 21 showed better psychometric properties as compared to the preceding version. A six-factor solution was obtained, explaining 61.3% of total variance. Then, factor scores were computed with the regression method, and a second-order factor analysis was performed. A two-factor solution was obtained, and the factors were clearly interpretable as ‘anxiety’ and ‘avoidance’. The pattern of correlations between ECR and RQ was as hypothesised, and the ECR was also found to possess good classification properties. Conclusion The Italian version of the ECR was confirmed to be reliable and valid. It might be useful for Italian researchers interested in adult attachment

Gamma Radiation from PSR B1055-52

The telescopes on the Compton Gamma Ray Observatory (CCRO) have observed PSR B1055-52 a number of times between 1991 and 1998. From these data, a more detailed picture of the gamma radiation from this source has been developed, showing several characteristics which distinguish this pulsar: the light curve is complex; there is no detectable unpulsed emission; the energy spectrum is flat, with no evidence of a sharp high-energy cutoff up to greater than 4 GeV. Comparisons of the gamma-ray data with observations at longer wavelengths show that no two of the known gamma-ray pulsars have quite the same characteristics; this diversity makes interpretation in terms of theoretical models difficult

The hr1 and Fusion Peptide Regions of the Subgroup B Avian Sarcoma and Leukosis Virus Envelope Glycoprotein Influence Low pH-Dependent Membrane Fusion

The avian sarcoma and leukosis virus (ASLV) envelope glycoprotein (Env) is activated to trigger fusion by a two-step mechanism involving receptor-priming and low pH fusion activation. In order to identify regions of ASLV Env that can regulate this process, a genetic selection method was used to identify subgroup B (ASLV-B) virus-infected cells resistant to low pH-triggered fusion when incubated with cells expressing the cognate TVB receptor. The subgroup B viral Env (envB) genes were then isolated from these cells and characterized by DNA sequencing. This led to identification of two frequent EnvB alterations which allowed TVB receptor-binding but altered the pH-threshold of membrane fusion activation: a 13 amino acid deletion in the host range 1 (hr1) region of the surface (SU) EnvB subunit, and the A32V amino acid change within the fusion peptide of the transmembrane (TM) EnvB subunit. These data indicate that these two regions of EnvB can influence the pH threshold of fusion activation

Outcomes of patients aged ≥26 years with relapsed or refractory B-cell acute lymphoblastic leukemia in ZUMA-3 and historical trials

Brexucabtagene autoleucel (brexu-cel) is an autologous anti-CD19 CAR T-cell therapy approved in the USA and European Union (EU) for adults with relapsed or refractory B-cell acute lymphoblastic leukemia (R/R B-ALL; aged ≥26 years in EU). Here, outcomes for patients with R/R B-ALL aged ≥26 years in ZUMA-3 treated with brexu-cel were compared with historical standard-of-care (SOC) therapy. After median follow-up of 26.8 months, the overall complete remission (CR) rate among patients treated with brexu-cel in Phase 2 ( N = 43) was 72% and median overall survival (OS) was 25.4 months (95% CI, 15.9-NE). Median OS was improved in Phase 2 patients versus matched historical SOC-treated patients. Compared with aggregate historical trial data, Phase 1 and 2 patients had improved OS versus blinatumomab, inotuzumab, and chemotherapy in a matching-adjusted indirect comparison (MAIC) study. These data demonstrate clinical benefit of brexu-cel relative to SOC in patients ≥26 years with R/R B-ALL