Design and implementation of synchronization and AGC for OFDM-based WLAN receivers

An efficient implementation of several tasks at the receiver becomes crucial in OFDM-based high-speed WLAN systems, such as automatic gain control, time and frequency synchronization and offset tracking. This paper deals with fixed point constraints and accuracy requirements for implementation of those algorithms. Also, a complete set of thresholds for the practical implementation of time and frequency synchronization sub-blocks is obtained. Moreover, a technique to mitigate the remaining frequency offset after coarse acquisition is proposed, yielding a good trade-off between performance and complexity. Finally, we propose the implementation of a simple and effective automatic gain control procedure.This work has been partially funded by Spanish government with project TIC 2002-03498 (ORISE), Telefonica I+D by the contract nº 25756, and the Chamber of Madrid Community and European Social Fund by a grant to the first author

El depósito de armas de la azucarera (Alfaro, La Rioja)

En el presente artículo se trata el hallazgo de un depósito de armas: espadas, puñal, casco y umbos de escudo, principalmente, localizados durante la excavación realizada en el año 1969 en la Azucarera de Alfaro (La Rioja). El material es bastante significativo dentro del contexto peninsular. Parece tratarse de un depósito ritual de la guerra sertoriana, de ahí su importancia y el interés de su publicación

On the chemical nature and orbit of meteoroids from the omicron draconid stream

The omicron Draconids were first observed by Denning in the 19th Century [1]. The activity was, however, modest, with a zenithal hourly rate (ZHR) of about 10–12. Denning [2] also reported observations in 1929 but in neither case was an orbit given, only a radiant position (RA ~271º, Dec. ~60º). However, for a considerable time after Denning’s observations, no records of any activity exist. Whether this is due to a lack of observers at the pertinent time (early July and thus close to the longest day and also close to the activity period of the delta Aquariids and observers may have preferred to study those) or an intrinsic lack of activity from the Omicron Draconids is not clear. The next record appears to be by Cook et al. [3] reporting on the work of the Harvard Meteor Project in the 1950s. In that paper they also suggested that the formation of the stream was associated with the disintegration of the nucleus of comet C/1919 Q2 Metcalf. In fact, our team recorded in 2008 a mag. -18 omicron Draconid fireball which was linked to this comet [4]. Here we present the analysis of a doublestation omicron-Draconid fireball recorded in the framework of our continuous fireball monitoring and spectroscopic campaigns in July 2007. The unique spectrum obtained for a member of this stream has provides helpful information about the chemical nature of meteoroids in the omicron-Draconid stream

Metastasis of renal clear-cell carcinoma to the oral mucosa, an atypical location

The majority of cases of metastatic tumors involve the mandible and some the maxilla but they are considerably less common in intraoral soft tissues. In addition, the primary tumor is known in the majority of cases; although in onethird of such cases, metastasis is the first clinical manifestation. The most common primary tumors metastasizing to the mouth are lung carcinoma in men and breast carcinoma in women. An oral metastasis implies a serious prognosis, as in the majority of patients there is multiple organ involvement at the time of diagnosis. We present the case of a 52-year old patient with renal pathology who came to the emergency room due to a rapidly increasing gingival tumor. With the provisional clinical diagnosis of a pyogenic granuloma,the tumor was excised. Subsequent anatomopathological analysis revealed a tumor metastasis compatible with clear-cell carcinoma, and its renal origin was confirmed by means of immunohistochemical techniques

Morphological Description of Frontal EEG Interictal and Ictal Discharges in an Adult Cohort of 175 Patients

EEG morphology; Electroencephalography; Frontal lobe seizuresMorfología EEG; Electroencefalografía; Convulsiones del lóbulo frontalMorfologia EEG; Electroencefalografia; Convulsions del lòbul frontalClinical and electroencephalogram (EEG) features in frontal lobe epilepsy (FLE) vary considerably among patients, making the diagnosis a challenge. The objective of this study was to describe interictal and ictal EEG activity, identifying variables that could help to differentiate and diagnose frontal lobe epilepsy cases. A prospective cross-sectional study from patients with frontal interictal epileptiform discharges (IED) referred to the Vall d’Hebron University Hospital (Barcelona, Spain) after a clinical event compatible with epileptic seizures was designed. The interictal and ictal activity were analyzed to provide a detailed EEG description of the cases, using different statistical analyses. The morphological seizure pattern at the ictal onset remained globally unchanged over time in seizures arising from the frontal lobe for each patient. Isolated sharp waves were the most frequent waveforms in the expression of IED. Frontal lobe seizures are frequently short and sometimes appear grouped in clusters within the same recording. Often the ictal expression of the electrical activity in frontal lobe seizure is subtle and challenging to interpret. A description of the main findings is summarized to identify seizures arising from the frontal lobe and avoid false negatives findings in EEG interpretations.This research received no external funding

Targeting of prolamins by RNAi in bread wheat: Effectiveness of seven silencing-fragment combinations for obtaining lines devoid of coeliac disease epitopes from highly immunogenic gliadins

Gluten proteins are responsible for the viscoelastic properties of wheat flour but also for triggering pathologies in susceptible individuals, of which coeliac disease (CD) and noncoeliac gluten sensitivity may affect up to 8% of the population. The only effective treatment for affected persons is a strict gluten-free diet. Here, we report the effectiveness of seven plasmid combinations, encompassing RNAi fragments from a-, c-, x-gliadins, and LMW glutenin subunits, for silencing the expression of different prolamin fractions. Silencing patterns of transgenic lines were analysed by gel electrophoresis, RP-HPLC and mass spectrometry (LC-MS/ MS), whereas gluten immunogenicity was assayed by an anti-gliadin 33-mer monoclonal antibody (moAb). Plasmid combinations 1 and 2 downregulated only c- and a-gliadins, respectively. Four plasmid combinations were highly effective in the silencing of x-gliadins and c-gliadins, and three of these also silenced a-gliadins. HMW glutenins were upregulated in all but one plasmid combination, while LMW glutenins were downregulated in three plasmid combinations. Total protein and starch contents were unaffected regardless of the plasmid combination used. Six plasmid combinations provided strong reduction in the gluten content as measured by moAb and for two combinations, this reduction was higher than 90% in comparison with the wild type. CD epitope analysis in peptides identified in LC-MS/MS showed that lines from three plasmid combinations were totally devoid of CD epitopes from the highly immunogenic a- and x-gliadins. Our findings raise the prospect of breeding wheat species with low levels of harmful gluten, and of achieving the important goal of developing nontoxic wheat cultivars

Protumorigenic effects of Snail-expression fibroblasts on colon cancer cells

et al.Snail1 is a transcriptional factor that plays an important role in epithelial–mesenchymal transition and in the acquisition of invasive properties by epithelial cells. In colon tumors, Snail1 expression in the stroma correlates with lower specific survival of cancer patients. However, the role(s) of Snail1 expression in stroma and its association with patients' survival have not been determined. We used human primary carcinoma-associated fibroblasts (CAFs) or normal fibroblasts (NFs) and fibroblast cell lines to analyze the effects of Snail1 expression on the protumorigenic capabilities in colon cancer cells. Snail1 expression was higher in CAFs than in NFs and, as well as α-SMA, a classic marker of activated CAFs. Moreover, in tumor samples from 50 colon cancer patients, SNAI1 expression was associated with expression of other CAF markers, such as α-SMA and fibroblast activation protein. Interestingly, coculture of CAFs with colon cells induced a significant increase in epithelial cell migration and proliferation, which was associated with endogenous SNAI1 expression levels. Ectopic manipulation of Snail1 in fibroblasts demonstrated that Snail1 expression controlled migration as well as proliferation of cocultured colon cancer cells in a paracrine manner. Furthermore, expression of Snail1 in fibroblasts was required for the coadjuvant effect of these cells on colon cancer cell growth and invasion when coxenografted in nude mice. Finally, cytokine profile changes, particularly MCP-3 expression, in fibroblasts are put forward as mediators of Snail1-derived effects on colon tumor cell migration. In summary, these studies demonstrate that Snail1 is necessary for the protumorigenic effects of fibroblasts on colon cancer cells.This research was supported by the PI12/02037, Fundación Científica AECC, SAF2010-20750, S2010/BMD-2344, RTICC-RD12/0036/0041 and by the Fundación Banco Santander. Antonio García de Herreros’ laboratory was supported by RTICC-RD12/0036/0005 and SAF 2010-16089. Ma Jesús Larriba’s laboratory was supported by RD12/0036/0021. Cristina Peña and José Miguel García are recipients of Miguel Servet Contracts from the Instituto de Salud Carlos III.Peer reviewe