Performance improvement of a broadcast-and-select (B&S) optical switch based on an electro-absorption modulator (EAM)-gate array is presented. The introduction of a novel spot-size converter (SSC) ...with an easy fabrication process reduced the optical coupling loss between the switch's waveguide array and input/output fibers and enhanced the optical-coupling tolerance for misalignment as the SSC properly expands the waveguide's mode field as well. In addition, the electrical crosstalk, which causes undesirable changes in the output power from different switch ports, was suppressed by the simple addition of a grounded electrode that covers the surface of passive waveguides, instead of employing a complicated regrowth process, as is usually done for electrical isolation between EAMs. A 4 x 4 B&S optical switch module has been fabricated with these improvements and has successfully exhibited low insertion loss (<; 15.3 dB), little variation in insertion loss, a fast switching time (<; 8 ns), low power consumption (<; 3 W), and a high extinction ratio (~50 dB).
We report hyperpolarization of the electronic spins associated with substitutional nitrogen defects in bulk diamond crystals. Hyperpolarization is achieved by optical pumping of nitrogen vacancy ...centers followed by rapid cross relaxation at the energy level matching condition in a 51 mT bias field. The maximum observed donor spin polarization is 0.9%, corresponding to an enhancement of 25 compared to the thermal Boltzmann polarization. A further accumulation of polarization is impeded by an anomalous optical saturation effect that we attribute to charge state conversion processes. Hyperpolarized nitrogen donors may form a useful resource for increasing the efficiency of diamond-based dynamic nuclear polarization devices.
Alteration of the AR functions due to amplification, overexpression and somatic mutation of the AR itself or altered interaction of AR with other cell growth regulatory proteins, may contribute to a ...significant subset of advanced prostate cancer (CaP). Very little is known about the pathways impacted by AR dysfunctions, although CaP associated AR alterations suggest the biological role of the AR dysfunction in disease progression. Comparative evaluations of wild type (wt) AR and mutant (mt) ARs in appropriate experimental models should provide a better understanding of the functional impact of AR alterations in CaP. Here, we provide direct evidence showing cell growth/cell survival promoting effects of the widely studied CaP associated AR mutation (T877A). In contrast to Ad-wtAR or Ad-control infected LNCaP or LAPC4 cells, Ad-mtAR (T877A) infected LNCaP or LAPC4 cells continued to grow in the androgen-deprived medium and exhibited an androgen independent AR-transcription factor activity. Further, Ad-mtAR (T877A) infected LNCaP or LAPC4 cells exhibited enhanced cell growth in the presence of lower concentrations of the synthetic androgen, R1881. Of note, Ad-mtAR (T877A) infected LNCaP cells showed striking resistance to cell growth inhibition/apoptosis mediated by the wt p53. Taken together, these findings provide novel insights into the AR dysfunctions resulting from the T877A mutation and functionally similar AR alterations may provide selective cell growth/survival advantage for CaP progression. These observations have important implications for developing biology-based prognostic biomarkers and therapeutic strategies for CaP showing such AR dysfunctions.
Endangered Australian southern right whales, Eubalaena australis, are vulnerable to threats from human activities, particularly at calving aggregation areas. As the population increases, new calving ...areas are being established, which are important to monitor. In the Encounter Bay/Lacepede Bay region, South Australia, distribution, relative abundance, residency and site fidelity were studied using historical sightings (n = 1071, 1970-2013) and photo-identified individuals (n = 191, 2006-2019). Whales were observed throughout the study area and concentrated in Encounter Bay during April to November where an inshore core calving area was identified between Port Elliot and the River Murray Mouth. Annual maximum daily sightings increased from 2 to 8 (
= 2.9) whales during 1983-1997 to 1-25 (
= 8.6) after 2002. Numbers of identified female-calf pairs (CC) increased from 10 (2006-2012) to 31 (2013-2019). During 2013-2019, when survey effort increased, a mean of 4.4 (1-9 pairs/year) CC and 18.0 (7-40/year) unaccompanied animals (UA) visited Encounter Bay each season. Mean residency was greater for CC (51.3, 13-126 days) than UA (13.4, 2-40 days). Calving females that arrived pregnant had more than twice the residency time than those first sighted with a calf. A quarter of calving females returned in two or three subsequent seasons. Encounter Bay is an important calving area and requires re-classification by the Commonwealth from "emerging aggregation area" to "small, established aggregation area". Ongoing research is needed to document southern right whale population dynamics at Encounter Bay in the context of the broader Australian population.
A widely tunable double-ring resonator-coupled laser is developed for use in a photonic packet switching system. By using a double-ring resonator as a wavelength-selective filter, full -band tuning ...operation is achieved with a low tuning current, and the fabrication process is simpler than that used for distributed-Bragg-reflector-type tunable lasers. A tuning range of 50.0 nm with a current injection of less than 7 mA is successfully demonstrated.
Abstract
Perchlorate is an oxidizer used in fireworks. Though fireworks displays are held over Lake Biwa, which supplies water to Kyoto, the city's water treatment process lacks the ability to remove ...perchlorate. This study investigated perchlorate contamination in source and tap water resulting from a fireworks display. During 2016, the perchlorate concentration in the source water increased to 22.3 μg/L during the 19 hours following the display and then decreased to <0.5 μg/L during the 43 hours following the display. The perchlorate concentration in the tap water increased to 13.6 μg/L during the 35 hours following the display, and then gradually decreased. To evaluate the state of mixing through the water treatment process, a model for chemical reactors was applied to concentration time-courses in the source and tap water. The model showed that perchlorate was dispersed homogeneously by stirring as the water flowed downstream through the waterway and through the water purification plant.
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