Real-time experimental demonstrations of software reconfigurable optical OFDM transceivers utilizing DSP-based digital orthogonal filters for SDN PONs.

Real-time optical OFDM (OOFDM) transceivers with on-line software-controllable channel reconfigurability and transmission performance adaptability are experimentally demonstrated, for the first time, utilizing Hilbert-pair-based 32-tap digital orthogonal filters implemented in FPGAs. By making use of an 8-bit DAC/ADC operating at 2GS/s, an oversampling factor of 2 and an EML intensity modulator, the demonstrated RF conversion-free transceiver supports end-to-end real-time simultaneous adaptive transmissions, within a 1GHz signal spectrum region, of a 2.03Gb/s in-phase OOFDM channel and a 1.41Gb/s quadrature-phase OOFDM channel over a 25km SSMF IMDD system. In addition, detailed experimental explorations are also undertaken of key physical mechanisms limiting the maximum achievable transmission performance, impacts of transceiver's channel multiplexing/demultiplexing operations on the system BER performance, and the feasibility of utilizing adaptive modulation to combat impairments associated with low-complexity digital filter designs. Furthermore, experimental results indicate that the transceiver incorporating a fixed digital orthogonal filter DSP architecture can be made transparent to various signal modulation formats up to 64-QAM.

Association between ancient bone preservation and dna yield: a multidisciplinary approach.

Ancient molecular typing depends on DNA survival in archaeological bones. Finding valuable tools to predict DNA presence in ancient samples, which can be measured prior to undertaking a genetic study, has become an important issue as a consequence of the peculiarities of archaeological samples. Since the survival of DNA is explained by complex interrelations of multiple variables, the aim of the present study was to analyze morphological, structural, chemical, and biological aspects of a set of medieval human bones, to provide an accurate reflection of the state of preservation of the bony components and to relate it with DNA presence. Archaeological bones that yielded amplifiable DNA presented high collagen content (generally more than 12%), low racemization values of aspartic acid (lesser than 0.08), leucine and glutamic acid, low infrared splitting factor, small size of crystallite, and more compact appearance of bone in the scanning electron micrographs. Whether these patterns are characteristic of ancient bones or specific of each burial site or specimen requires further investigation.

Distribution of HLA DQ A1 alleles and genotypes in two Spanish populations (Aragon and Asturias).

HLA DQ A1 is probably one of the PCR-based genetic marker systems most widely used in actual forensic casework analyses. As accurate data about the distribution of the alleles is one of the most important prerequisites for the application in forensic biology, we studied the allele distribution in two relevant Spanish populations (Aragonese and Asturian). Results were in good agreement with the Hardy-Weinberg law in both Aragonese and Asturian populations. The power of discrimination was 0.92 in the Aragonese and 0.93 in Asturian sample. A test for homogeneity of the HLA DQ A1 population data based on alelle frequency counts for 12 European samples was performed and no significant differences were found (P = 0.831).

Aggressions against healthcare workers: an approach to the situation in Spain and the victims psychological effects.

Aggression against healthcare workers is a problem of important consequences which is becoming a focus of research. However, its possible effects on psychological health have not been studied sufficiently in spite of the fact that they may be of importance even in the absence of physical aggression [Winstnaley S, Whittington R. Aggression towards health care staff in a UK general hospital: variation among professions. J Clin Nurs 2004;13:3-10,[1]].

Endoftalmitis endógena. Respuesta del autor / Endogenous endophthalmitis. Reply

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Panoftalmitis endógena en un paciente diabético / Endogenous panophtalmitis in a diabetic patient

La endoftalmitis endógena es una complicación muy infrecuente de las sepsis1,2 que puede ser causada por diversos microorganismos1 y se presenta de forma mayoritaria en sujetos inmunodeprimidos o con enfermedades crónicas3. En la mayoría de pacientes se observa un foco extraocular y es bilateral en aproximadamente un 25 por ciento de los casos3. La panoftalmitis es todavía más infrecuente y generalmente suele abocar a ceguera, atrofia o enucleación del globo ocular3. Presentamos el caso de un paciente diabético con panoftalmitis bilateral metastásica (AU)