High-Power High-Efficiency Laser Power Transmission at 100m Using Optimized Multi-Cell GaAs Converter

A high-power high-efficiency laser power transmission system at 100m based on an optimized multi-cell GaAs converter capable of supplying 9.7W of electricity is demonstrated. An I-V testing system integrated with a data acquisition circuit and an analysis software is designed to measure the efficiency and the I-V characteristics of the laser power converter (LPC). The dependencies of the converter’s efficiency with respect to wavelength, laser intensity and temperature are analyzed. A diode laser with 793nm of wavelength and 24W of power is used to test the LPC and the software. The maximum efficiency of the LPC is 48.4% at an input laser power of 8W at room temperature. When the input laser power is 24W (laser intensity of 60000W/m2), the efficiency is 40.4% and the output voltage is 4 V. The overall efficiency from electricity to electricity is 11.6%.

Evaluation of the PV cell operation temperature in the process of fast switching to open-circuit mode

A procedure for measuring the overheating temperature (ΔT ) of a p-n junction area in the structure of photovoltaic (PV) cells converting laser or solar radiations relative to the ambient temperature has been proposed for the conditions of connecting to an electric load. The basis of the procedure is the measurement of the open-circuit voltage (VO C ) during the initial time period after the fast disconnection of the external resistive load. The simultaneous temperature control on an external heated part of a PV module gives the means for determining the value of VO C at ambient temperature. Comparing it with that measured after switching OFF the load makes the calculation of ΔT possible. Calibration data on the VO C = f(T ) dependences for single-junction AlGaAs/GaAs and triple-junction InGaP/GaAs/Ge PV cells are presented. The temperature dynamics in the PV cells has been determined under flash illumination and during fast commutation of the load. Temperature measurements were taken in two cases: converting continuous laser power by single-junction cells and converting solar power by triple-junction cells operating in the concentrator modules.

Social transmission of reproductive behavior increases frequency of inherited disorders in a young-expanding population

The observation of high frequencies of certain inherited disorders in the population of Saguenay–Lac Saint Jean can be explained in terms of the variance and the correlation of effective family size (EFS) from one generation to the next. We have shown this effect by using the branching process approach with real demographic data. When variance of EFS is included in the model, despite its profound effect on mutant allele frequency, any mutant introduced in the population never reaches the known carrier frequencies (between 0.035 and 0.05). It is only when the EFS correlation between generations is introduced into the model that we can explain the rise of the mutant alleles. This correlation is described by a c parameter that reflects the dependency of children’s EFS on their parents’ EFS. The c parameter can be considered to reflect social transmission of demographic behavior. We show that such social transmission dramatically reduces the effective population size. This could explain particular distributions in allele frequencies and unusually high frequency of certain inherited disorders in some human populations.

Accurate reconstruction of a known HIV-1 transmission history by phylogenetic tree analysis.

Phylogenetic analyses are increasingly used in attempts to clarify transmission patterns of human immunodeficiency virus type 1 (HIV-1), but there is a continuing discussion about their validity because convergent evolution and transmission of minor HIV variants may obscure epidemiological patterns. Here we have studied a unique HIV-1 transmission cluster consisting of nine infected individuals, for whom the time and direction of each virus transmission was exactly known. Most of the transmissions occurred between 1981 and 1983, and a total of 13 blood samples were obtained approximately 2-12 years later. The p17 gag and env V3 regions of the HIV-1 genome were directly sequenced from uncultured lymphocytes. A true phylogenetic tree was constructed based on the knowledge about when the transmissions had occurred and when the samples were obtained. This complex, known HIV-1 transmission history was compared with reconstructed molecular trees, which were calculated from the DNA sequences by several commonly used phylogenetic inference methods [Fitch-Margoliash, neighbor-joining, minimum-evolution, maximum-likelihood, maximum-parsimony, unweighted pair group method using arithmetic averages (UPGMA), and a Fitch-Margoliash method assuming a molecular clock (KITSCH)]. A majority of the reconstructed trees were good estimates of the true phylogeny; 12 of 13 taxa were correctly positioned in the most accurate trees. The choice of gene fragment was found to be more important than the choice of phylogenetic method and substitution model. However, methods that are sensitive to unequal rates of change performed more poorly (such as UPGMA and KITSCH, which assume a constant molecular clock). The rapidly evolving V3 fragment gave better reconstructions than p17, but a combined data set of both p17 and V3 performed best. The accuracy of the phylogenetic methods justifies their use in HIV-1 research and argues against convergent evolution and selective transmission of certain virus variants.

Maternal plasma human immunodeficiency virus type 1 RNA level: a determinant and projected threshold for mother-to-child transmission.

To prevent mother-to-child human immunodeficiency virus type 1 (HIV-1) transmission, it is important to identify its determinants. Because HIV-1 RNA levels can be reduced by antiviral therapy, we examined the role of maternal plasma HIV-1 RNA level in mother-to-child transmission. We used quantitative competitive PCR to measure HIV-RNA in 30 infected pregnant women and then followed their infants prospectively; 27% of the women transmitted HIV-1 to their infants and maternal plasma HIV-1 RNA level correlated strikingly with transmission. Eight of the 10 women with the highest HIV-1 RNA levels at delivery (190,400-1,664,100 copies per ml of plasma) transmitted, while none of the 20 women with lower levels (500-155,800 copies per ml) did (P = 0.0002). Statistical analysis of the distribution of HIV-1 RNA loads in these 30 women projected a threshold for mother-to-child transmission in a larger population; the probability of a woman with a viral RNA level of < or = 100,000 copies per ml not transmitting is predicted to be 97%. Examination of serial HIV-1 RNA levels during pregnancy showed that viral load was stable in women who did not initiate or change antiviral therapy. These data identify maternal plasma HIV-1-RNA level as a major determinant of mother-to-child transmission and suggest that quantitation of HIV-1 RNA may predict the risk of transmission.

Import competition from China and unemployment. An analysis using Spanish workers’micro-data.

In the period 1997-2011, import competition from China multiplied by five in the Spanish manufacturing sector. In this paper we analyze whether this severe increase in import competition from China is associated with a higher probability of becoming unemployed in the Spanish manufacturing sector. Linking industry-level data on imports with the working histories of 141,000 manufacturing workers, we show that import competition from China is positively associated with the probability of becoming unemployed. In particular, a standard deviation increase in import competition from China raises the probability of becoming unemployed between 0.8 and 3.5 percentage points, which represents between a 9% and a 44% increase relative to the unconditional probability of becoming unemployed. In contrast, we do not find any effect of import competition from China on manufacturing wages. Also, our estimations show that there is weak evidence of a positive association between a higher import competition from China and the probability of switching to an employment outside the manufacturing sector.

Power line interference filtering on surface electromyography based on the stationary wavelet packet transform

Power line interference is one of the main problems in surface electromyogram signals (EMG) analysis. In this work, a new method based on the stationary wavelet packet transform is proposed to estimate and remove this kind of noise from EMG data records. The performance has been quantitatively evaluated with synthetic noisy signals, obtaining good results independently from the signal to noise ratio (SNR). For the analyzed cases, the obtained results show that the correlation coefficient is around 0.99, the energy respecting to the pure EMG signal is 98–104%, the SNR is between 16.64 and 20.40 dB and the mean absolute error (MAE) is in the range of −69.02 and −65.31 dB. It has been also applied on 18 real EMG signals, evaluating the percentage of energy respecting to the noisy signals. The proposed method adjusts the reduction level to the amplitude of each harmonic present in the analyzed noisy signals (synthetic and real), reducing the harmonics with no alteration of the desired signal.

SeismicWaveTool: Continuous and discrete wavelet analysis and filtering for multichannel seismic data

A MATLAB-based computer code has been developed for the simultaneous wavelet analysis and filtering of multichannel seismic data. The considered time–frequency transforms include the continuous wavelet transform, the discrete wavelet transform and the discrete wavelet packet transform. The developed approaches provide a fast and precise time–frequency examination of the seismograms at different frequency bands. Moreover, filtering methods for noise, transients or even baseline removal, are implemented. The primary motivation is to support seismologists with a user-friendly and fast program for the wavelet analysis, providing practical and understandable results.

Switching Axial Progenitors from Producing Trunk to Tail Tissues in Vertebrate Embryos

The vertebrate body is made by progressive addition of new tissue from progenitors at the posterior embryonic end. Axial extension involves different mechanisms that produce internal organs in the trunk but not in the tail. We show that Gdf11 signaling is a major coordinator of the trunk-to-tail transition. Without Gdf11 signaling, the switch from trunk to tail is significantly delayed, and its premature activation brings the hindlimbs and cloaca next to the forelimbs, leaving extremely short trunks. Gdf11 activity includes activation of Isl1 to promote formation of the hindlimbs and cloaca-associated mesoderm as the most posterior derivatives of lateral mesoderm progenitors. Gdf11 also coordinates reallocation of bipotent neuromesodermal progenitors from the anterior primitive streak to the tail bud, in part by reducing the retinoic acid available to the progenitors. Our findings provide a perspective to understand the evolution of the vertebrate body plan.

Genotypic Resistance Tests Sequences Reveal the Role of Marginalized Populations in HIV-1 Transmission in Switzerland.

Targeting hard-to-reach/marginalized populations is essential for preventing HIV-transmission. A unique opportunity to identify such populations in Switzerland is provided by a database of all genotypic-resistance-tests from Switzerland, including both sequences from the Swiss HIV Cohort Study (SHCS) and non-cohort sequences. A phylogenetic tree was built using 11,127 SHCS and 2,875 Swiss non-SHCS sequences. Demographics were imputed for non-SHCS patients using a phylogenetic proximity approach. Factors associated with non-cohort outbreaks were determined using logistic regression. Non-B subtype (univariable odds-ratio (OR): 1.9; 95% confidence interval (CI): 1.8-2.1), female gender (OR: 1.6; 95% CI: 1.4-1.7), black ethnicity (OR: 1.9; 95% CI: 1.7-2.1) and heterosexual transmission group (OR:1.8; 95% CI: 1.6-2.0), were all associated with underrepresentation in the SHCS. We found 344 purely non-SHCS transmission clusters, however, these outbreaks were small (median 2, maximum 7 patients) with a strong overlap with the SHCS'. 65% of non-SHCS sequences were part of clusters composed of >= 50% SHCS sequences. Our data suggests that marginalized-populations are underrepresented in the SHCS. However, the limited size of outbreaks among non-SHCS patients in-care implies that no major HIV outbreak in Switzerland was missed by the SHCS surveillance. This study demonstrates the potential of sequence data to assess and extend the scope of infectious-disease surveillance.

An Approach to Assessment of the Technical Condition of Overhead Transmission Lines

The approach of estimating the current state of the overhead transmission lines is considering. The performance functions of the overhead transmission lines has been generated on the basis of experimental data and reports. Results of simulation of the approximation functions for overhead transmission lines are analyzed.

Data compilation of ESOP

The work in this sub-project of ESOP focuses on the advective and convective transforma-tion of water masses in the Greenland Sea and its neighbouring areas. It includes observational work on the sub-mesoscale and analysis of hydrographic data up to the gyre-scale. Observations of active convective plumes were made with a towed chain equipped with up to 80 CTD sensors, giving a horizontal and vertical resolution of the hydrographic fields of a few metres. The observed scales of the penetrative convective plumes compare well with those given by theory. On the mesoscale the structure of homogeneous eddies formed as a result of deep convection was observed and the associated mixing and renewal of the intermediate layers quantified. The relative importance and efficiency of thermal and haline penetrative convection in relation to the surface boundary conditions (heat and salt fluxes and ice cover) and the ambient stratification are studied using the multi year time series of hydro-graphic data in the central Greenland Sea. The modification of the water column of the Greenland Sea gyre through advection from and mixing with water at its rim is assessed on longer time scales. The relative contributions are quantified using modern water mass analysis methods based on inverse techniques. Likewise the convective renewal and the spreading of the Arctic Intermediate Water from its formation area is quantified. The aim is to budget the heat and salt content of the water column, in particular of the low salinity surface layer, and to relate its seasonal and interannual variability to the lateral fluxes and the fluxes at the air-sea-ice interface. This will allow to estimate residence times for the different layers of the Greenland Sea gyre, a quantity important for the description of the Polar Ocean carbon cycle.