Combining beta-core fragment and total oestriol measurements to test for Down syndrome pregnancies

Recent articles by Cuckle et al., Canick et al., and Isozaki et al. have evaluated urine beta-core fragment as a screening test for Down syndrome in second-trimester pregnancies. They found over four-fold elevation of beta-core fragment levels in Down syndrome pregnancies, and between 62 and 88 per cent detection of this trisomy at a 5 per cent false-positive rate. Urine beta-core fragment may be a superior screening test for Down syndrome pregnancies. In the present study, urinary total oestriol has been evaluated as a marker to use in combination with beta-core fragment in screening for Down syndrome pregnancies. The two markers were evaluated separately in relation to the urine creatinine concentration. To amplify screening performance, we evaluated the ratio of beta-core fragment to total oestriol levels (creatinine-independent). beta-core fragment and total oestriol levels were determined (normalized to creatinine, ng/mg creatinine) in urine samples from 480 unaffected and 12 Down syndrome pregnancies, collected consecutively at a single prenatal diagnosis centre. The median beta-core fragment level in Down syndrome cases was 4.5 MOM. Fifty-eight per cent of Down syndrome cases had beta-core fragment levels exceeding the 95th centile of unaffected pregnancies. The median total oestriol level in Down syndrome cases was 0.33 MOM. Forty-two per cent of Down syndrome cases had total oestriol levels exceeding the 95th centile of unaffected pregnancies. We investigated the ratio of the two determinants (beta-core fragment, ng/ml divided by total oestriol, ng/ml) in our sample set. The median beta-core fragment:total oestriol ratio in Down syndrome cases was 13 MOM. Seventy-five per cent of Down syndrome cases had a ratio exceeding the 95th and the 99.5th centile of unaffected pregnancies. Total oestriol complements beta-core fragment in urine screening for Down syndrome pregnancies. A test measuring the ratio of the two urine determinants may be a significant improvement over current serum methods for detecting Down syndrome.     

Modeling citation worthiness by using attention-based bidirectional long short-term memory networks and interpretable models

Scientometrics - Scientist learn early on how to cite scientific sources to support their claims. Sometimes, however, scientists have challenges determining where a citation should be...     

Reflector Antenna Analysis Using the Complex Equivalent Length Concept: Reciprocity and Coupling Between Feeds

This work presents a procedure for analyzing multiply fed reflector antennas in both transmission and reception modes, by using the Reflector Antenna Complex Equivalent Length (RA-CEL) concept. The RA-CEL is derived by combining the Feed Element Complex Equivalent Length (FE-CEL) Method with an Equivalent Current (EC) model on the reflector surface. This formulation, in terms of both electric and magnetic equivalent currents, is consistent with the reciprocity theorem. Its application to reflector antenna far-field pattern analysis, in both the transmission and reception modes, is presented. The proposed method accurately considers the mutual coupling among feeding array elements through the reflector surface, and its computational cost is substantially lower than required by a full-wave analysis. Some applications investigating the mutual coupling among feeding elements of reflector antennas are presented, and are compared with a reference solution given by the Method of Moments - Physical Optics hybrid method, and a numerical evaluation of the integral equation.     

Cochannel and adjacent channel interference in actual terrestrial TV scenarios - part II: MATV systems laboratory tests

For pt.I, see Sanchez, M.G. et al., ibid., p.111-15. The results of an extensive study on analog PAL signals interfered with by digital DVB-T signals are presented. The study covers a theoretical evaluation of the interference problems, field and laboratory measurements and a national survey among TV installation companies. Field measurements are reported in part I. These measurements explain the origin of cochannel and some of the adjacent channel interference problems. However, interference was reported in areas where the field measurements showed that the protection ratios for PAL signals interfered with by DVB-T adjacent channel signals were met. As these reports came from multistorey buildings with master antenna TV (MATV) installations, the study was extended to analyze the role of these installations in the interference problems. Part of the interference problems are due to the MATV system amplifiers which are unable to cope with adjacent channel DVB-T signals. The nonlinear amplifiers give rise to intermodulation problems. The ITU-R recommendations (see ITU-R BT.1368, 2000) recognize that such nonlinear amplifiers could be a source of problems and that higher protection ratios may be needed, but no value is given for the increase. Our laboratory tests of commercial amplifiers found that an increase in the protection ratios of between 12 to 16 dB is needed to avoid a significant degradation of the PAL TV signal in the amplifiers. It has also been found that most of the interference situations are not due to the interfering signal being a DVB-T format, but that any significant signal amplitude in the passband of the filter causes interference. Therefore, MATV system distribution needs planning factors associated with the distribution of any signals near the main signal. The results are presented of a survey conducted among companies who install communal telecommunication infrastructures in Spain.     

Cochannel and adjacent channel interference in actual terrestrial TV scenarios - part I: field measurements

The results of an extensive study on analog PAL signals interfered with by digital DVB-T signals are presented. The research work covers field measurements, laboratory measurements, a theoretical evaluation of the interference problems and a national survey among TV installation companies. The main objective is the identification and explanation of the interference problems reported since the start of DVB-T broadcasting. The report is organized in two parts. This paper, part I, describes the field measurements, whereas the laboratory measurements and the poll results are described in part II (see Acuna, M.A. et al., ibid., p.116-22). It has been found that the frequency plan is part of the source of the interference problems, particularly in the case of cochannel interference. Another source of problems is use of different radiation elements at the same site for broadcasting DVB-T and analog TV signals. As stated in ETSI documents (see ETSI TR-101-190, 1997), the use of a different antennas for DVB-T may require ERP restrictions to protect existing analog services. The power ratios between digital and analog TV signals at the broadcasting station should be adjusted to meet the protection ratios everywhere within the coverage area. The required power ratio depends on the specific shape of the radiation pattern of each antenna. Finally, it has been found that an important part of the interference problems is due to the amplifiers of the master antenna television (MATV) systems in buildings. The results of the laboratory tests and the theoretical analysis conducted to determine the increment of the protection ratio required by the presence of these amplifiers are presented in part II.     

Immunological assessment of exposure to Echinococcus granulosus in a rural dog population in Uruguay

An ELISA was used to screen a dog population in Uruguay (Sarandi Del Yi, Durazno District) for the prevalence of specific serum antibodies (IgG, IgA and IgE) to Echinococcus granulosus. The sensitivity (61%) and specificity (97%) of the ELISA were determined using well-defined serum groups. A total of 408 dogs from Sarandi del Yi and environs were screened serologically, and 29.7% (8.6-13.8% for each antibody class) of dogs had positive levels of antibody to E. granulosus. This antibody prevalence (exposure) was significantly higher than the percentage of dogs found to be positive for E. granulosus worms by arecoline purgation (7.6%). This level of exposure to E. granulosus determined by ELISA is considered unacceptable from a public health perspective. Measures will now focus on obtaining data on the true prevalence of current infection in this dog population and on determining the transmission patterns of the disease in this endemic region.     

Insight of electrical behavior in ferroelectric‐semiconductor polymer nanocomposite films of PVDF/ZnSe and PVDF/Cu:ZnSe

Nanocomposite thin films (NCTF) of low‐dimensional ZnSe and copper doped ZnSe integrated poly(vinylidene fluoride) (PVDF) polymer were developed via simple solution casting method. Herein, ZnSe and Cu:ZnSe nanoparticles were synthesized through the chemical reduction technique. The obtained low‐dimensional nanoparticles and NCTFs were characterized by XRD, SEM/EDS, TEM, and FTIR analysis. Room temperature dielectric and ferroelectric characteristics of PVDF/ZnSe flexible NCTF exhibited superior dielectric and ferroelectric behavior with a high coercive field of 15.6 V. Whereas, the dielectric and ferroelectric characteristics were greatly diminished in the PVDF/Cu:ZnSe flexible NCTF was due to the conducting behavior of copper ions at the interface of the polymer network. These results indicated that the PVDF/ZnSe flexible NCTF will be a potential candidate for advanced electrical applications and device fabrication. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44983.     

Shear force control for a terahertz near field microscope

We report on the advancement of apertureless terahertz microscopy by active shear force control of the scanning probe. Extreme subwavelength spatial resolution and a maximized image contrast are achieved by maintaining a tip-surface distance of about 20 nm. The constant distance between scanning tip and surface results in terahertz images that mirror the dielectric permittivity of the surface.     

Emphasizing human capabilities in software development

People are a critical software development issue, and the human dimension can be even more important than the technical. An important part of human resources management is assigning people to development roles. This process isn't just crucial for generating productive teams; it can also help software organizations develop systematic long-term competence. Despite the importance of identifying the right people for roles, little is known about doing this properly. Integrating managerial experience with a procedure for identifying the person best suited for each role can help improve human resources management and long-term career development. We've defined a human capability-based procedure to supplement managerial activities for supporting personnel development and human resources management. Along with occupational psychologists and software managers, we've applied our procedure in small and medium-sized enterprises (SMEs).     

The IRM Fluxgate Magnetometer

This report describes the three-axis fluxgate magnetometer instrument on board the AMPTE IRM spacecraft. Important features of the instrument are its wide dynamic range (0.1-60 000 nT), a high resolution (16-bit analog to digital conversion) and the capability to operate automatically or via telecommand in two gain states. In addition, the wave activity is monitored in all three components up to 50 Hz. Inflight checkout proved the nominal functioning of the instrument in all modes.