Ultrafast switching of photonic entanglement

To deploy and operate a quantum network which utilizes existing telecommunications infrastructure, it is necessary to be able to route entangled photons at high speeds, with minimal loss and signal-band noise, and---most importantly---without disturbing the photons' quantum state. Here we present a switch which fulfills these requirements and characterize its performance at the single photon level; it exhibits a 200-ps switching window, a 120:1 contrast ratio, 1.5 dB loss, and induces no measurable degradation in the switched photons' entangled-state fidelity (< 0.002). Furthermore, because this type of switch couples the temporal and spatial degrees of freedom, it provides an important new tool with which to encode multiple-qubit states in a single photon. As a proof-of-principle demonstration of this capability, we demultiplex a single quantum channel from a dual-channel, time-division-multiplexed entangled photon stream, effectively performing a controlled-bit-flip on a two-qubit subspace of a five-qubit, two-photon state

Evaluation of Co-existence of Helicobacter pylori and candida in the Oral Cavity of Dyspeptic patients

In our group comprising of 70 subjects, 60 patients presented with symptomatic gastritis and 10 were asymptomatic subjects who served as the control group. The symptomatic gastritis subjects had undergone endoscopy and gastric biopsy specimen was collected. Histopathologically, the biopsy specimen was observed for the presence of Helicobacter pylori. The subjects were divided into 3 groups. Group I comprised of 30 subjects with Helicobacter pylori in their gastric mucosa. Group II comprised of 30 subjects without Helicobacter pylori in their gastric mucosa. Group III comprised of 10 asymptomatic controls. • We found that there was a male predominance for gastritis in our study groups. The symptomatic gastritis was more commonly seen between the 3rd and 5th decade of life. • Our study findings conclude that subjects who are less than 30 years of age are more prone to have Candida in their saliva. • There was no difference in the mean CFU between the study groups and the mean CFU between the age groups did not show statistical difference. But, when stratified between gender, there was an increase in CFU with increasing age. • We found that oral candida carriage was more frequently seen in the younger age group and odd’s have shown that when compared to subjects above 50 years, symptomatic subjects less than 30 years have 7.5 times higher risk of getting salivary candidal carriage. • We found that there is no correlation between the presence or absence of salivary Helicobacter pylori and the presence or absence of Helicobacter pylori in the gastric mucosa. There was no correlation between salivary candida and the presence or absence of Helicobacter pylori in the gastric mucosa. • In our study, the patients with Candida and Helicobacter pylori in the saliva had 8 times more chance of having gastritis with Helicobacter pylori positivity in their gastric mucosa than in whom these organisms were not detected. • Further studies are needed to understand the relationship of Helicobacter pylori, Candida and gastritis

The Significance of Urban Gardening on the Household Economy: A Case of Minority Urban Gardeners

Urban gardening (UG) is an emerging approach to increase the consumption of fresh produce in the homestead. The objective of this exploratory case study was to enhance the technical and economic efficiency of small, socially disadvantaged, and minority (SSDM) urban gardeners in Maryland. Twenty-two SSDM producers engaged in UG participated in the study. The findings showed that farmers were operating rationally, and cultivating diversified specialty, medicinal, and ethnic crops, with an average of twenty specialty/ethnic crops on 1.2 acres. The farmers reported six primary reasons for sustaining urban gardening: family consumption (79%), outdoor and physical activity (79%), supplemental household income (57%), leisure (50%), experiential learning for family members (14%), and tax benefits (7%). Findings revealed that 96% of the farmers strengthened knowledge in reducing production costs, increasing farm income (86%), enhancing entrepreneurial skills (82%), improving farm management practices (73%), mitigating risk (59%), and changing UG behaviors and actions (100%)

All-optical switching of photonic entanglement

Future quantum optical networks will require the ability to route entangled photons at high speeds, with minimal loss and added in-band noise, and---most importantly---without disturbing the photons' quantum state. Here we present an all-optical switch which fulfills these requirements and characterize its performance at the single photon level. It exhibits a 200-ps switching window, 120:1 contrast, 1.5-dB loss, and induces no measurable degradation in the switched photons' entangled-state fidelity (< 0.002). As a proof-of-principle demonstration of its capability, we use the switch to demultiplex a single quantum channel from a dual-channel, time-division-multiplexed entangled photon stream. Furthermore, because this type of switch couples the temporal and spatial degrees of freedom, it provides an important new tool with which to encode multiple-qubit quantum states on a single photon

Evaluating Hydrological Model Performances on Stream Flow Simulation with Agricultural Management

Two comprehensive agricultural watershed-scale hydrological models: Soil and Water Assessment Tool (SWAT), and Annualized Agricultural Non-Point Source Pollution Model (AnnAGNPS), have been widely used for evaluating agricultural Best Management Practice (BMP). In this study, models were developed for the Big Sunflower River Watershed (BSRW) in Mississippi, USA. Both hydrological models were successfully calibrated and validated for predicting monthly stream flow discharges from three USGS gages (Merigold, Sunflower, and Leland) within the BSRW. The model performances were reasonable with R2 and NSE values range from 0.45 to 0.84 for SWAT, and from 0.34 to 0.66 for AnnAGNPS. Both models predicted lower stream flow discharge with conservation tillage practice as compare to conventional tillage practice BMP evaluated in this study. Overall, results showed that both SWAT and AnnAGNPS models successfully simulated hydrological conditions of the watershed with agricultural BMP, and these models can be useful for making hydrological decisions related to agricultural watershed managements. Keywords: SWAT, AnnAGNPS, tillage, streamflow, hydrology, BMP DOI: 10.7176/JEP/12-3-03 Publication date: January 31st 202

Interaction-Free All-Optical Switching via Quantum-Zeno Effect

We propose a novel interaction-free scheme for all-optical switching which does not rely on the physical coupling between signal and control waves. The interaction-free nature of the scheme allows it to overcome the fundamental photon-loss limit imposed by the signal-pump coupling. The same phenomenon protects photonic-signal states from decoherence, making devices based on this scheme suitable for quantum applications. Focusing on $\chi^{(2)}$ waveguides, we provide device designs for traveling-wave and Fabry-Perot switches. In both designs, the performance is optimal when the signal switching is induced by coherent dynamical evolution. In contrast, when the switching is induced by a rapid dissipation channel, it is less efficient.Comment: 14 pages, 14 figures, submitted to Physical Review

Heralding Single Photons Without Spectral Factorability

Recent efforts to produce single photons via heralding have relied on creating spectrally factorable two-photon states in order to achieve both high purity and high production rate. Through a careful multimode analysis, we find, however, that spectral factorability is not necessary. Utilizing single-mode detection, a similar or better performance can be achieved with non-factorable states. This conclusion rides on the fact that even when using a broadband filter, a single-mode measurement can still be realized, as long as the coherence time of the triggering photons exceeds the measurement window of the on/off detector.Comment: 7 pages, 5 figure