Low-Cost Method for Waveguide Device Components Fabrication at 220 – 325 GHz

This work explores a rapid design and manufacturing approach to realize complex 3D pillar type filter and transmission line structures for applications in the 220 - 325 GHz range and which cannot be economically reproduced by conventional machining processes or present rapid prototyping methods. The significance of this investigation is that at sub-millimetre-wave or THz frequencies, where the waveguide features are less than 100μm and the skin depths are less than 200nm, the exact conductor shape and surface roughness have a significant electrical effect and any variations result in an important disagreement between the modelled and measured characteristics. This is a proof of concept validation of the rapid manufacturing approach and is aimed at paving the way to a range of THz passive waveguide components, where the availability and cost of such components is typically prohibitive and where the surface roughness is minimized and highly reproducible. Using this approach the fabrication times can be as rapid as a few days and can yield many hundreds of highly reproducible millimetre scale components

Large Signal Analysis of a New Meander Line Topology for W-band Traveling Wave Tubes

Satellite distribution of high data rate needs wide frequency band. The millimeter waves, in particular the W-band, provide wide bandwidth and relatively low attenuation. The link transmission power can be provided only by Traveling Wave Tubes (TWTs). A new meander line topology to be used as slow wave structure for 71-76 GHz TWTs, with improved performance in comparison to the conventional one, is proposed. The new meander line compared to a standard meander line shows flatter gain and higher output power. © 2019 IEEE

Grey squirrels in central Italy: a new threat for endemic red squirrel subspecies

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Stability prediction of early orthopedic treatment in Class III malocclusion: morphologic discriminant analysis

Background To evaluate morphologic differences between class III malocclusion success and failure treatment subjects in order to identify which variables are more predictive for long-term stability in early orthopedic treatment. In this retrospective study, 31 patients were enrolled from the Department of Orthodontics (Rome Tor Vergata). Inclusion criteria were as follows: white ancestry, class III malocclusion, mixed dentition, cervical stage (CS) 1-2, no pseudo-class III. Pre-treatment radiographic and cast records were collected. Each patient underwent rapid maxillary expansion/facial mask/bite block (RME/FM/BB) orthopedic treatment until correction. At T1 (permanent dentition, CS4), records were recollected. According to treatment stability, relapse group (RG, 19) and success group (SG, 12) were identified. Sagittal and vertical cephalometric and digital cast measurements were performed. Student's t tests were used for statistically significant differences inter and intra groups. For discriminant analysis, relapse or success status was added to each patient's T0 data. Results At T0, RG showed larger upper anterior transversal width (p = 0.0266), while at T1 the upper anterior length was shorter than SG (p = 0.0028). Between T1 and T0, both groups showed larger upper anterior and posterior transversal widths. SG had greater upper anterior (p = 0.0066) and posterior (p = 0.449) sagittal length. RG presented larger lower anterior (p = 0.0012) and posterior (p = 0.0002) transversal widths, while there were no differences in SG lower arch. Discriminant analysis provided two predictive variables with an accuracy of 80.6%: upper anterior length and upper posterior length. Conclusion A shorter and wider maxilla could be a predisposing factor for relapse and failure of the early orthopedic treatment of class III malocclusion patients. The absence of mandibular changes could be predictable for treatment success

Pollen and nectar sources used by honeybee colonies pollinating sunflower (Helianthus annuus) in the Colorado River Valley, Argentina

Pollen traps and beeswax foundations were set in order to study pollen and nectar sources used by honeybee colonies pollinating sunflower (Helianthus annuus L.) for the production of hybrid seed in the lower valley of the Colorado river in southern Argentina. Thirty-seven plant species in bloom were registered in the area surrounding the sunflower field. Most of them were scarcely represented. The honeybee maximum density recorded on the sunflower male-fertile line was 10.00 bees per 100 heads, while on the male-sterile line was 25.33 bees per 100 heads. Seven plant taxa were identified in the pollen loads and 26 in the honey samples. About 84% of the collected pollen came from three taxa: Centaurea solstitialis L., Eucalyptus camaldulensis Dehnh. and Cirsium vulgare (Savi) Airy -Shaw, and only 11% came from H. annuus. The taxa most gathered had high protein values, above 20%. The dominant and secondary pollen types in honey samples were Tamarix gallica L., E. camaldulensis, Brassicaceae and C. solstitialis. The results indicate that honeybees (Apis mellifera L.) foraged pollen and nectar mainly from the flora surrounding the sunflower field.Fuentes de polen y néctar utilizadas por colonias de Apis mellifera que polinizan girasol (Helianthus annuus) en el valle inferior del río Colorado, Argentina. Se colocaron trampas caza-polen y cuadros con cera estampada para estudiar las fuentes de polen y néctar utilizadas por colmenas que polinizan girasol para la producción de semilla híbrida en el valle inferior del río Colorado, Argentina. Treinta y siete especies en floración fueron registradas en cercanías al cultivo de girasol. La mayoría de ellas estuvieron escasamente representadas. La máxima densidad de abejas en la línea androfértil de girasol fue de 10,00 abejas por cada 100 inflorescencias, mientras que en la línea androestéril fue de 25,33 abejas por cada 100 inflorescencias. En las cargas polínicas se identificaron siete taxa, y 26 en las muestras de miel. El 84% en peso del polen recolectado correspondió a tres taxa: Centaurea solstitialis L., Eucalyptus camaldulensis Dehnh. y Cirsium vulgare (Savi) Airy -Shaw y sólo el 11% provino de H. annuus. Los taxa más cosecha-dos tuvieron valores de proteína altos, superiores a 20%. Los tipos polínicos dominantes y secun-darios en las muestras de miel fueron Tamarix gallica L. y E. camaldulensis, Brassicaceae y C. solstitialis. Los resultados indican que las abejas (Apis mellifera L.) recolectaron polen y néctar principalmente de la flora circundante al cultivo de girasol

Stability prediction of early orthopedic treatment in Class III malocclusion: morphologic discriminant analysis

Abstract Background To evaluate morphologic differences between class III malocclusion success and failure treatment subjects in order to identify which variables are more predictive for long-term stability in early orthopedic treatment. In this retrospective study, 31 patients were enrolled from the Department of Orthodontics (Rome Tor Vergata). Inclusion criteria were as follows: white ancestry, class III malocclusion, mixed dentition, cervical stage (CS) 1-2, no pseudo-class III. Pre-treatment radiographic and cast records were collected. Each patient underwent rapid maxillary expansion/facial mask/bite block (RME/FM/BB) orthopedic treatment until correction. At T1 (permanent dentition, CS4), records were recollected. According to treatment stability, relapse group (RG, 19) and success group (SG, 12) were identified. Sagittal and vertical cephalometric and digital cast measurements were performed. Student’s t tests were used for statistically significant differences inter and intra groups. For discriminant analysis, relapse or success status was added to each patient’s T0 data. Results At T0, RG showed larger upper anterior transversal width (p = 0.0266), while at T1 the upper anterior length was shorter than SG (p = 0.0028). Between T1 and T0, both groups showed larger upper anterior and posterior transversal widths. SG had greater upper anterior (p = 0.0066) and posterior (p = 0.449) sagittal length. RG presented larger lower anterior (p = 0.0012) and posterior (p = 0.0002) transversal widths, while there were no differences in SG lower arch. Discriminant analysis provided two predictive variables with an accuracy of 80.6%: upper anterior length and upper posterior length. Conclusion A shorter and wider maxilla could be a predisposing factor for relapse and failure of the early orthopedic treatment of class III malocclusion patients. The absence of mandibular changes could be predictable for treatment success

Millimeter Wave Traveling Wave Tubes for the 21st Century

Traveling wave tubes are rapidly evolving to provide unprecedented power level in comparison to solid state devices in the millimeter waves region of the spectrum (80 – 300 GHz) thus enabling a wide range of applications. Wireless communications, imaging, security, plasma diagnostics, healthcare and many others will gain substantial features if high power in the millimeter wave region would be available from compact sources. The development of fabrication technologies is proving crucial for introducing new topologies and structures for millimeter wave vacuum electronic devices, compatible with the dimensions dictated by the short wavelength that poses substantial challenges due to tight tolerances and surface quality. This review paper will provide an overview of the principles, evolution and state of the art of one of the most widely utilized vacuum electronic devices, the traveling wave tube (TWT). The wide band, high gain features of TWTs make those devices the most promising solutions for high power at millimeter waves and THz frequencies

The OPERA magnetic spectrometer

The OPERA neutrino oscillation experiment foresees the construction of two magnetized iron spectrometers located after the lead-nuclear emulsion targets. The magnet is made up of two vertical walls of rectangular cross section connected by return yokes. The particle trajectories are measured by high precision drift tubes located before and after the arms of the magnet. Moreover, the magnet steel is instrumented with Resistive Plate Chambers that ease pattern recognition and allow a calorimetric measurement of the hadronic showers. In this paper we review the construction of the spectrometers. In particular, we describe the results obtained from the magnet and RPC prototypes and the installation of the final apparatus at the Gran Sasso laboratories. We discuss the mechanical and magnetic properties of the steel and the techniques employed to calibrate the field in the bulk of the magnet. Moreover, results of the tests and issues concerning the mass production of the Resistive Plate Chambers are reported. Finally, the expected physics performance of the detector is described; estimates rely on numerical simulations and the outcome of the tests described above.Comment: 6 pages, 10 figures, presented at the 2003 IEEE-NSS conference, Portland, OR, USA, October 20-24, 200

Prenatal Exposure to DEHP Affects Spermatogenesis and Sperm DNA Methylation in a Strain-Dependent Manner.

Di-(2-ethylhexyl)phtalate (DEHP) is a plasticizer with endocrine disrupting properties found ubiquitously in the environment and altering reproduction in rodents. Here we investigated the impact of prenatal exposure to DEHP on spermatogenesis and DNA sperm methylation in two distinct, selected, and sequenced mice strains. FVB/N and C57BL/6J mice were orally exposed to 300 mg/kg/day of DEHP from gestation day 9 to 19. Prenatal DEHP exposure significantly decreased spermatogenesis in C57BL/6J (fold-change = 0.6, p-value = 8.7*10-4), but not in FVB/N (fold-change = 1, p-value = 0.9). The number of differentially methylated regions (DMRs) by DEHP-exposure across the entire genome showed increased hyper- and decreased hypo-methylation in C57BL/6J compared to FVB/N. At the promoter level, three important subsets of genes were massively affected. Promoters of vomeronasal and olfactory receptors coding genes globally followed the same trend, more pronounced in the C57BL/6J strain, of being hyper-methylated in DEHP related conditions. In contrast, a large set of micro-RNAs were hypo-methylated, with a trend more pronounced in the FVB/N strain. We additionally analyze both the presence of functional genetic variations within genes that were associated with the detected DMRs and that could be involved in spermatogenesis, and DMRs related with the DEHP exposure that affected both strains in an opposite manner. The major finding in this study indicates that prenatal exposure to DEHP can decrease spermatogenesis in a strain-dependent manner and affects sperm DNA methylation in promoters of large sets of genes putatively involved in both sperm chemotaxis and post-transcriptional regulatory mechanisms

Altas concentraciones de flúor y oligoelementos asociados en aguas del sur de la llanura Pampeana

We investigated the levels of F and its relationship with As, B and V in ground and surface waters of the southern Pampas, where cases of dental and skeletal fluorosis, and arsenic in hair and urine samples have been detected in the rural population. Eating vegetables and cereals grown in irrigated areas with excessive fluoride may increase the risk of fluorosis due to the addition of the extra F contributed from other sources such as drinking water. Moreover, if these elements exceed the tolerance of crops produce toxicity and, like salinity, they decrease the potential crop yield. Within an area of 2300 km2, 81 samples were taken from surface and groundwaters to determine F, As, B and V. Fluoride was detected in 86% of the sampled groundwaters, and in 65% of the surface waters reaching maximun concentrations of 7.12 mg/L and of 6.5 mg/L, respectively. Risk areas were determined based on the distribution of F in the unconfined aquifer; the highest concentrations were observed towards the S-SW, in the central and SE sectors. On he surface flow, the highest concentrations were found at the west with sampling points remarkably prominent. These waters are classified as sodium-sulfate, C3 and with high concentrations of F, B and V that could produce toxicity and reduce yields on irrigated crops. Fluoride correlated significantly (p<0.01) with As (r=0.75), B (r=0.57) and V (r=0.53) in groundwater; it also associated with As (r = 0.65) in surface waters, and showed higher levels of association with boron (r=0.88) and vanadium (r=0.81), which showed highly significant linear regressions (p<0.01).Se investigaron los niveles de F y su relación con As, B y V en aguas freáticas y superficiales del sur de la Llanura Pampeana, donde se detectaron casos de fluorosis dental, esquelética y presencia de arsénico en muestras de cabello y orina, en la población rural. El consumo de vegetales y cereales cultivados en áreas irrigadas con excesivo flúor podrían incrementar el riesgo de fluorosis a raíz de la adición de F suplementario al aportado desde otras fuentes como el agua de bebida. Por otra parte, si estos elementos sobrepasan la tolerancia de los cultivos producen toxicidad, y al igual que la salinidad disminuyen el rendimiento potencial. Sobre un área de 2.300 km2, se tomaron 81 muestras de aguas subterráneas y superficiales, de cuyo análisis se determinó la presencia de F, As, B y V. Se detectaron concentraciones de F de hasta un máximo de 12.7 mg/L en 86% de las muestras de agua freática, y valores de hasta 6.5 mg/L en 65% de las muestras de aguas superficiales. Se determinaron áreas de riesgo en función de la distribución del F en el acuífero freático, observándose las mayores concentraciones hacia el S-SO, en el centro y SE. En el flujo superficial, las mayores concentraciones se encontraron sobre el sector oeste, con puntos de muestreo notablemente destacados. Estas aguas se clasifican como sódicas-sulfatadas, C3 y con elevadas concentraciones de F, B y V que podrían producir toxicidad en los cultivos cuando son regados, disminuyendo los rendimientos. En las aguas freáticas el F se correlacionó significativamente (p<0,01) con As (r=0,75), B (r=0,57) y V (r=0,53); en aguas superficiales también se asoció con As (r=0,65) y se registraron mayores niveles de asociación con boro (r=0,88) y vanadio (r=0,81), que presentaron regresiones lineales altamente significativas (p<0,01).Fil: Espósito, Martín Eduardo. Universidad Nacional del Sur. Departamento de Agronomia. Laboratorio de Hidrologia y Riego; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); ArgentinaFil: Sequeira, Mario Eduardo. Universidad Nacional del Sur. Departamento de Ingenieria. Laboratorio de Hidraulica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); ArgentinaFil: Paoloni, Juan Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Blanco, M. C.. Universidad Nacional del Sur. Departamento de Agronomia. Laboratorio de Hidrologia y Riego; ArgentinaFil: Amiotti, N.. Universidad Nacional del Sur. Departamento de Agronomia. Laboratorio de Hidrologia y Riego; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); Argentin