Efficiency of Entanglement Concentration by Photon Subtraction

We introduce a measure of efficiency for the photon subtraction protocol aimed at entanglement concentration on a single copy of bipartite continuous variable state. We then show that iterating the protocol does not lead to higher efficiency than a single application. In order to overcome this limit we present an adaptive version of the protocol able to greatly enhance its efficiency.Comment: 6 pages, 3 figures, accepted by Physica Script

Wage Work for Women: The Menstrual Cycle and the Power of Water

We hypothesise that women's participation in wage (off-farm) work is reduced when their greater water needs due to the menstrual cycle are not met because their household has poor access to water. For testing, we use the data from rural villages in China. Controlling for village fixed effects, poor access to water is found to decrease the probability of wage work participation of affected (pre-menopause) women by about 10 percentage points, a large effect. As expected, there is no adverse causal impact of poor household access to water for women post-menopause, or for men, ceteris paribus.wage work, women, menopause, water engineering, rural development, China

The Gender Education Gap in China: The Power of Water

We investigate girls' school dropout rates, bringing forward a novel variable: access to water. We hypothesise that a girl's education suffers when her greater water need for female hygiene purposes after menarche is not met because her household has poor access to water. For testing we use data from rural villages in the China Health and Nutrition Survey. We find that menarche is associated with an increase in the school dropout rate, and indeed the effect is weaker for girls who have good access to water. Water engineering can thus contribute significantly to reducing gender education gaps in rural areas.education, gender gaps, menarche, water, China

Effects of Spatial Pattern of GreenSpace on Land Surface Temperature: A case study on Oasis City Aksu, northwest China

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.The urban heat island (UHI) refers to the phenomenon of higher atmospheric and surface temperatures occurring in urban areas than in the surrounding rural areas. Numerous studies have shown that increased percent cover of greenspace (PLAND) can significantly decrease land surface temperatures (LST). Fewer studies, however, have investigated the effects of configuration of greenspace on LST. This thesis aims to fill this gap using oasis city Aksu, northwest China as a case study. PLAND along with two configuration metrics were used to measure the composition and configuration of greenspace. The metrics were calculated by moving window method based on a greenspace map derived from Landsat Thematic Mapper (TM) imagery, and LST data were retrieved from Landsat TM thermal band. Normalized mutual information measure was employed to investigate the relationship between LST and the spatial pattern of greenspace. The results showed that PLAND was the most important predictor of LST. Configuration of greenspace also significantly affected LST. In addition, the variance of LST was largely explained by both composition and configuration of greenspace. Results from this study can expand our understanding of the relationship between LST and vegetation, and provide insights for improving urban greenspace planning and management

INSULIN ACTIONS ON HIPPOCAMPAL NEURONS

Aging is the main risk factor for cognitive decline. The hippocampus, a brain region critical for learning and memory formation, is especially vulnerable to normal and pathological age-related cognitive decline. Dysregulation of both insulin and intracellular Ca2+ signaling appear to coexist and their compromised actions may synergistically contribute to neuronal dysfunction with aging. This dissertation focused on the interaction between insulin, Ca2+ dysregulation, and cognition in hippocampal neurons by examining the contributions of insulin to Ca2+ signaling events that influence memory formation. I tested the hypothesis that insulin would increase cognition in aged animals by altering Ca2+-dependent physiological mechanisms involved in learning. The possible effects of insulin on learning and memory in young and aged rats were studied. In addition, the effects of insulin on the Ca2+-dependent afterhyperpolarization in CA1 pyramidal hippocampal neurons from young and aged animals were compared. Further, primary hippocampal cultures were used to examine the possible effects of insulin on voltage-gated Ca2+ channel activity and Ca2+-induced Ca2+-release; mechanisms known to influence the AHP. We found that intranasal insulin improved memory in aged F344 rats. Young and aged F344 rats were treated with Humalog®, a short-acting insulin analog, or Levemir®, a long-acting insulin analog. The aged rats performed similar to young rats in the Morris Water Maze, a hippocampal dependent spatial learning and memory task. Electrophysiological recordings from CA1 hippocampal neurons revealed that insulin reduced the age-related increase in the Ca2+-dependent afterhyperpolarization, a prominent biomarker of brain aging that is associated with cognitive decline. Patch clamping recording from hippocampal cultured neurons showed that insulin reduced Ca2+ channel currents. Intracellular Ca2+ levels were also monitored using Fura-2 in response to cellular depolarization. Results indicated that a reduction in Ca2+-induced Ca2+-release from intracellular stores occurred in the presence of insulin. These results suggest that increasing brain insulin levels in aged rats may have improved memory by reducing the AHP and intracellular Ca2+concentrations. This study indicates a possible mechanism responsible for the beneficial effects of intranasal insulin on cognitive function absorbed in selective Alzheimer’s patients. Thus, insulin therapy may reduce or prevent age-related compromises to Ca2+ regulatory pathways typically associated with cognitive decline

Study of Inkjet Printing as an Ultra-Low-Cost Antenna Prototyping Method and Its Application to Conformal Wraparound Antennas for Sounding Rocket Sub-Payload

Inkjet printing is an attractive patterning technology that has received tremendous interest as a mass fabrication method for a variety of electronic devices due to its manufacturing exibility and low-cost feature. However, the printing facilities that are being used, especially the inkjet printer, are very expensive. This thesis introduces an extremely cost-friendly inkjet printing method using a printer that costs less than $100. In order to verify its reliability, linearly and circularly polarized (CPd) planar and conformal microstrip antennas were fabricated using this printing method, and their measurement results were compared with copper microstrip antennas. The result shows that the printed microstrip antennas have similar performances to those of the copper antennas except for lower efficiency. The effects of the conductivity and thickness of the ink layer on the antenna properties were studied, and it is found that the conductivity is the main factor affecting the radiation efficiency, though thicker ink yields more effective antennas. This thesis also presents the detailed antenna design for a sub-payload. The sub-payload is a cylindrical structure with a diameter of six inches and a height of four inches. It has four booms coming out from the surface, which are used to measure the variations of the energy flow into the upper atmosphere in and around the aurora. The sub-payload has two types of antennas: linearly polarized (LPd) S-band antennas and right-hand circularly polarized (RHCPd) GPS antennas. Each type of antenna has various requirements to be fully functional for specific research tasks. The thesis includes the design methods of each type of antenna, challenges that were confronted, and the possible solutions that were proposed. As a practical application, the inkjet printing method was conveniently applied in validating some of the antenna designs

Kinetics and coverage dependent reaction mechanisms of the copper atomic layer deposition from copper dimethylamino-2-propoxide and diethylzinc

Atomic layer deposition (ALD) has been recognized as a promising method to deposit conformal and uniform thin film of copper for future electronic devices. However, many aspects of the reaction mechanism and the surface chemistry of copper ALD remain unclear. In this paper, we employ plane wave density functional theory (DFT) to study the transmetalation ALD reaction of copper dimethylamino-2-propoxide [Cu(dmap)2] and diethylzinc [Et2Zn] that was realized experimentally by Lee et al. [ Angew. Chem., Int. Ed. 2009, 48, 4536−4539]. We find that the Cu(dmap)2 molecule adsorbs and dissociates through the scission of one or two Cu–O bonds into surface-bound dmap and Cu(dmap) fragments during the copper pulse. As Et2Zn adsorbs on the surface covered with Cu(dmap) and dmap fragments, butane formation and desorption was found to be facilitated by the surrounding ligands, which leads to one reaction mechanism, while the migration of ethyl groups to the surface leads to another reaction mechanism. During both reaction mechanisms, ligand diffusion and reordering are generally endothermic processes, which may result in residual ligands blocking the surface sites at the end of the Et2Zn pulse, and in residual Zn being reduced and incorporated as an impurity. We also find that the nearby ligands play a cooperative role in lowering the activation energy for formation and desorption of byproducts, which explains the advantage of using organometallic precursors and reducing agents in Cu ALD. The ALD growth rate estimated for the mechanism is consistent with the experimental value of 0.2 Å/cycle. The proposed reaction mechanisms provide insight into ALD processes for copper and other transition metals