Who talks about collaborative spaces, how, and why

Communities in urban contexts and firms in corporate offices have recently started to implement collaborative spaces. Several authors from different disciplines are currently advancing knowledge in this realm. Systematizing this diverse knowledge base helps to advance our understanding of this novel phenomenon. To this end, the present work reviews 29 papers focusing on collaborative spaces. We analyse these papers in terms of contents, research methods, fields of study, authors’ background, and impact on the academic community. Grounding on this analysis, we outline new relevant research questions and opportunities for future investigations

1-Gb/s Transmission Over a Phosphorescent White LED by Using Rate-Adaptive Discrete Multitone Modulation

Light-emitting diodes (LEDs), which will be increasingly used in lighting technology, will also allow for distribution of broadband optical wireless signals. Visible-light communication (VLC) using white LEDs offers several advantages over the RF-based wireless systems, i.e., license-free spectrum, low power consumption, and higher privacy. Mostly, optical wireless can provide much higher data rates. In this paper, we demonstrate a VLC system based on a white LED for indoor broadband wireless access. After investigating the nonlinear effects of the LED and the power amplifier, a data rate of 1 Gb/s has been achieved at the standard illuminance level, by using an optimized discrete multitone modulation technique and adaptive bit- and power-loading algorithms. The bit-error ratio of the received data was 1.5 10^(-3), which is within the limit of common forward error correction (FEC) coding. These results twice the highest capacity that had been previously obtained

Enhanced 10 Gb/s operations of directly modulated reflective semiconductor optical amplifiers without electronic equalization

We report enhanced 10 Gb/s operation of directly modulated bandwidth-limited reflective semiconductor optical amplifiers. By using a single suitable arrayed waveguide grating we achieve simultaneously WDM demultiplexing and optical equalization. Compared to previous approaches, the proposed system results significantly more tolerant to seeding wavelength drifts. This removes the need for wavelength lockers, additional electronic equalization or complex digital signal processing. Uniform C-band operations are obtained experimentally with < 2 dB power penalty within a wavelength drift of 10 GHz (which doubles the ITU-T standard recommendations)

The Italian research project ROAD-NGN ‘Optical frequency/wavelength division multiple access techniques for next generation networks'

The paper describes the activities of the Italian national research project ROAD-NGN ‘Optical frequency/wavelength division multiple access techniques for next generation networks’; the project aims to investigate and experiment new technological solutions to facilitate the migration of access systems from copper to optical fibre, and to help the integration with broadband wireless architectures, with particular interest for the backhauling of the fourth generation (4G) Long Term Evolution (LTE) networks. The approaches, based on the orthogonal frequency division multiplexing (OFDM) and wavelength division multiplexing (WDM) techniques, can enable the unbundling of the local loop (ULL) and are upgradable toward very ultra wideband systems

A Possible Periodicity in the Radio Lightcurves of 3C454.3

During the period 1966.5 - 2006.2 the 15GHz and 8GHz lightcurves of 3C454.3 (z=0.859) show a qsasi-periodicity of ~12.8 yr (~6.9 yr in the rest frame of the source) with a double-bump structure. This periodic behaviour is interpreted in terms of a rotating double-jet model in which the two jets are created from the black holes in a binary system and rotate with the period of the orbital motion. The periodic variations in the radio fluxes of 3C454.3 are suggested to be mainly due to the lighthouse effects (or the variation in Doppler boosting) of the precessing jets which are caused by the orbital motion. In addition, variations in the mass-flow rates accreting onto the black holes may be also involved.Comment: 15 pages, 11 figure

The correlated optical and radio variability of BL Lacertae. WEBT data analysis 1994-2005

Since 1997, BL Lacertae has undergone a phase of high optical activity, with the occurrence of several prominent outbursts. Starting from 1999, the Whole Earth Blazar Telescope (WEBT) consortium has organized various multifrequency campaigns on this blazar, collecting tens of thousands of data points. One of the main issues in the study of this huge dataset has been the search for correlations between the optical and radio flux variations, and for possible periodicities in the light curves. The analysis of the data assembled during the first four campaigns (comprising also archival data to cover the period 1968-2003) revealed a fair optical-radio correlation in 1994-2003, with a delay of the hard radio events of ~100 days. Moreover, various statistical methods suggested the existence of a radio periodicity of ~8 years. In 2004 the WEBT started a new campaign to extend the dataset to the most recent observing seasons, in order to possibly confirm and better understand the previous results. In this campaign we have collected and assembled about 11000 new optical observations from twenty telescopes, plus near-IR and radio data at various frequencies. Here, we perform a correlation analysis on the long-term R-band and radio light curves. In general, we confirm the ~100-day delay of the hard radio events with respect to the optical ones, even if longer (~200-300 days) time lags are also found in particular periods. The radio quasi-periodicity is confirmed too, but the "period" seems to progressively lengthen from 7.4 to 9.3 years in the last three cycles. The optical and radio behaviour in the last forty years suggests a scenario where geometric effects play a major role. In particular, the alternation of enhanced and suppressed optical activity (accompanied by hard and soft radio events, respectively) canComment: 6 pages, 4 figure

Development of a LAMP assay for detection of Leishmania infantum infection in dogs using conjunctival swab samples

Background: Leishmania infantum infections in dogs play a crucial role in the transmission of pathogens causing visceral leishmaniasis to humans in the Gansu province, northwest China. To be able to control zoonotic transmission of the parasite to humans, a non-invasive loop-mediated isothermal amplification (LAMP) assay to specifically detect L. infantum infections in dogs was developed. Methods: The primers used in the LAMP assay were designed to target kinetoplast DNA minicircle sequences of the L. infantum isolate MCAN/CN/90/SC and tested using DNA isolated from promastigotes of different Leishmania species. The LAMP assay was evaluated with conjunctional swab samples obtained from 111 and 33 dogs living in an endemic and a non-endemic region of zoonotic visceral leishmaniasis in the Gansu province, respectively. The LAMP assay was also compared with conventional PCR, ELISA and microscopy using conjunctional swab, serum and bone marrow samples from the dogs, respectively. Results: The LAMP assay detected 1 fg of L. infantum DNA purified from cultured promastigotes which was 10-fold more sensitive than a conventional PCR test using Leishmania genus-specific primers. No cross reaction was observed with DNA isolated from promastigotes of L. donovani, L. major, L. tropica, and L. braziliensis, and the L. infantum reference strain MHOM/TN/80/IPT1. The L. infantum-positive rates obtained for field-collected samples were 61.3%, 58.6%, 40.5% and 10.8% by LAMP, PCR, ELISA and microscopy, respectively. As only one out of the 33 samples from control dogs from the non-endemic region of zoonotic visceral leishmaniasis was positive by the LAMP assay and the PCR test, the observed true negative rate (specificity) was 97% for both methods. Conclusion: This study has shown that the non-invasive, conjunctional swab-based LAMP assay developed was more sensitive in the detection of leishmaniasis in dogs than PCR, ELISA and microscopy. The findings indicate that the LAMP assay is a sensitive and specific method for the field surveillance of domestic dogs, particularly of asymptomatic canines, in ZVL-endemic areas in western China

A search for periodicity in the light curves of selected blazars

We present an analysis of multifrequency light curves of the sources 2223-052 (3C 446), 2230+114 (CTA 102), and 2251+158 (3C 454.3), which had shown evidence of quasi-periodic activity. The analysis made use of data from the University of Michican Radio Astronomy Observatory (USA) at 4.8, 8, and 14.5 GHz, as well as the Metsahovi Radio Astronomy Observatory (Finland) at 22 and 37 GHz. Application of two different methods (the discrete autocorrelation function and the method of Jurkevich) both revealed evidence for periodicity in the flux variations of these sources at essentially all frequencies. The periods derived for at least two of the sources -- 2223-052 and 2251+158-- are in good agreement with the time interval between the appearance of successive VLBI components. The derived periods for 2251+158 (P = 12.4 yr and 2223-052 (P = 5.8 yr) coincide with the periods found earlier by other authors based on optical light curves.Comment: 27 pages, 11 figures, accepted for publication in Astronomy Report

DIAGNOSIS AND PROGNOSIS OF ADRENAL BENIGN AND MALIGNANT TUMORS: NEW INSIGHTS FROM A COMPUTERIZED OPERATOR-INDEPENDENT MORPHOMETRIC MODEL AND PROTEOMIC EXPRESSION

Background: High mitotic index, high nuclear grade and reticulin distruption are part of representative hallmarks of adrenocortical cancer (ACC). A characteristic neutrophil/T-lymphocytes infiltrate ratio has been often implicated in carcinogenesis, progression and clinical outcome of several cancer types. However, its role in adrenal cortical tumors is unclear. Histology-based diagnosis may also suffer of a moment of subjectivity due to inter- and intra-observer variations. Proteomic studies of malignant tumors represent the future both for possible diagnostic and prognostic implication; whole proteome analysis of adrenocortical tumors from fresh tissues may represent the lacking piece of puzzling management of this tumor. Aim: to assess by computerized morphometry morphological features, vascular, inflammatory, reticulin and proliferative index pattern in adrenocortical adenomas (ACAs) and carcinomas and to assess proteomic profiles from adrenocortical tumors fresh tissues. Methods: A single Institution series of 11 ACAs and 18 ACCs samples was analyzed using a Kontron-Zeiss KS400 image analyzer. Four consecutive sections 4 \ub5m thick were obtained with a total of 250\u2013300 HPF examined for each case. Immunohistochemistry for Ki67, reticulin and CD8/CD15 was obtained. To minimize subjectivity, particularly relevant when quantitative results are expected, we generated a morphometric model based on analysis of volume fractions occupied by Ki67 positive and negative cells (nuclei, cytoplasm) and inflammatory compartments (CD15+ granulocytes, CD8+ lymphocytes) and reticulin framework surface. Lastly, the assessment of Ki-67 by computerized morphometry was compared with pathologist\u2019s evaluation. After sample preparation protocol of 7 ACCs, 5 ACAs and 5 normal adrenal tissue samples, difference In Gel Electrophoresis (DIGE) and following the protein spots individuation and isolation, Mass Spectrometry, were performed to allow protein identification. Results: The volume fraction of Ki-67 positive cells was highest in ACC. The volume fraction of nuclei in unit volume and the nuclear/cytoplasmic ratio in both Ki-67 negative cells and Ki-67 positive cells were prominent in ACC. The surface fraction of reticulin was considerably lower in ACC. Moreover, when comparing morphometric analysis of Ki67+ cells to pathologist\u2019s scores, the data of the point grid analysis revealed significantly lower values compared to conventional histopathology. These values, once statistically analyzed, demonstrated that our morphometric model could improve the sensitivity and specificity of Ki-67 evaluation in ACCs and ACAs (reaching 94% of sensitivity, 100% of specificity) and also that it cold contribute to a better prognosis definition. Proteomics individuated 62% overexpressed proteins in ACCs with respect to ACAs: among them vimentin and vitamin D-binding protein resulted the most varied (3.2 and 3-fold more expressed in ACCs than in ACAs respectively). On the other hand the remaining 38% of proteins resulted under-expressed in ACCs with regard to ACAs, being cathepsin D and aldose reductase both 3-fold less expressed in ACCs than in ACAs. The protein profile of ACCs versus normal adrenal tissue was similar (although with slight differences in terms of fold variation) to that of ACCs versus ACAs; nonetheless a varied new protein (lactate dehydrogenase, 1.8 fold increase in ACCs) with a possible role in tumorigenesis and tumor progression, was detected. Conclusions: Our computerized morphometric model is simple, lacks observer or subjective bias and can be used to supplement objective methods to achieve precise and reader-independent quantification of morphological characteristics and histological biomarkers of adrenocortical tumors. We speculate that the assessment of inflammatory infiltrate may found a place in the diagnostic algorithm of adrenal benign and malignant tumors. The promising preliminary results obtained by the proteomic study of ACCs and ACAs could contribute to the identification of new histological biomarkers. These data, once integrated into a complex algorithm including histological assessment, morphometric analysis and clinical data evaluation would easily contribute to create a prognostic stratification of ACCs with clear advantages for the clinical management of the disease