Dark Matter in Gauge Mediation from Emergent Supersymmetry

We investigated the viability of neutralino dark matter in the gauge mediation from emergent supersymmetry proposal. In this proposal, supersymmetry is broken at Planck scale and consequently, the gravitino is superheavy and completely decouples from the low energy theory. Squarks and sleptons obtain their soft masses dominantly through gauge mediation with other mechanisms highly suppressed. The lightest supersymmetric partner, in contrast to traditional gauge mediation, is a neutralino which is also a dark matter candidate. By explicit calculation of the low energy spectra, the parameter space was constrained using the WMAP observed relic density of dark matter, LEP2 Higgs mass bounds, collider bounds on supersymmetric partners and exotic B-meson decays. We found that the model has intriguing hybrid features such as a nearly gauge-mediated spectrum (the exception being the superheavy gravitino) but with a dominant mSUGRA-like bino-stau coannihilation channel and at large $\tan \beta$, A-resonance-like annihilation.Comment: 14 pages, 4 figure

Behavior of hydrophobic ionic liquids as liquid membranes on phenol removal: Experimental study and optimization

Room temperature ionic liquids show potential as an alternative to conventional organic membrane solvents mainly due to their properties of low vapor pressure, low volatility and they are often stable. In the present work, the technical feasibilities of room temperature ionic liquids as bulk liquid membranes for phenol removal were investigated experimentally. Three ionic liquids with high hydrophobicity were used and their phenol removal efficiency, membrane stability and membrane loss were studied. Besides that, the effects of several parameters, namely feed phase pH, feed concentration, NaOH concentration and stirring speeds on the performance of best ionic liquid membrane were also evaluated. Lastly, an optimization study on bulk ionic liquid membrane was conducted and the maximum phenol removal efficiency was compared with the organic liquid membranes. The preliminary study shows that high phenol extraction and stripping efficiencies of 96.21% and 98.10%, respectively can be achieved by ionic liquid membrane with a low membrane loss which offers a better choice to organic membrane solvents. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down

Improving the chromatic dispersion tolerance in long-haul fibre links using the coherent optical orthogonal frequency division multiplexing

Numerical simulations of the coherent optical orthogonal frequency division multiplexing modems are undertaken to investigate the effect of the adaptive modulation, the number of sub-carriers, the cyclic prefix (CP) length, the clipping ratio, quantisation bit resolution and the sampling speed of analogue-to-digital converters (ADCs) on the chromatic dispersion (CD) of a single mode fibre (SMF) at data rates up to 80 Gbps. The use of a large number of sub-carriers is more effective in combating fibre dispersion than employing a long CP; moreover, the optimum number of sub-carriers in the presence of both SMF non-linearities and CD has been identified. The authors show that using a high bit resolution ADC with a high clipping ratio, the transmission distance can be increased at specific data rates. Furthermore, it is shown that ADCs with a low sampling speed also improve the system tolerance to the fibre CD. In addition, simulation results show that the use of adaptive modulation schemes improves spectrum usage efficiency, thus resulting in higher tolerance to the CD when compared with the case in which identical modulation formats are adopted across all sub-carriers

Patient reported and physician recorded bowel dysfunction following colorectal resection and radical cystectomy: a prospective, comparative study

AIM: Bowel dysfunction following anterior resection (AR) is termed 'low anterior resection syndrome (LARS)'. It is unclear whether such dysfunction occurs following other bowel/pelvic operations as well. This study aimed to characterise and compare bowel dysfunction following AR, right hemicolectomy (RH) and radical cystectomy (RC). METHOD: A prospective study of consecutive patients undergoing AR, RH, and RC (2002-2012) was performed at a tertiary referral centre in Sydney, Australia. Outcome measures included: (i) patient-reported (satisfaction with bowel function, self-described bowel function, and self-reported change in bowel function); (ii) objective assessment of bowel function using validated criteria to identify symptoms and stratify patients into those with constipation and/or faecal incontinence (FI); and (iii) health-related quality of life (SF-36v2). RESULTS: Of 743 eligible patients, 70% participated (AR: n=338, mean age 69.6yrs [SD11.9], 59% male; RH: n=150, 75.8yrs [SD10.5], 54% male; RC: n=34, 71.1yrs [SD14.1], 71% male). AR patients were three times more likely to report change in bowel function post-surgery, and self-judged their bowel function as 'abnormal' more frequently (64%) than following RH (35%) and RC (35%) (P<0.01). AR patients were four times more likely to meet criteria for concomitant constipation and FI. Patients with concomitant constipation and FI had lower physical and mental SF-36v2 scores (P<0.001). CONCLUSION: Bowel dysfunction occurred after RH and RC but rates were higher following AR. This suggests that LARS occurs due to a direct impact of partial/complete loss of the rectum rather than just due to loss of bowel length and/or the consequence(s) of pelvic dissection.Kheng-Seong Ng, Marc A Gladma

Electronic theory for the normal state spin dynamics in Sr2_2RuO4_4: anisotropy due to spin-orbit coupling

Using a three-band Hubbard Hamiltonian we calculate within the random-phase-approximation the spin susceptibility, $\chi({\bf q},\omega)$, and NMR spin-lattice relaxation rate, 1/T$_1$, in the normal state of the triplet superconductor Sr$_2$RuO$_4$ and obtain quantitative agreement with experimental data. Most importantly, we find that due to spin-orbit coupling the out-of-plane component of the spin susceptibility $\chi^{zz}$ becomes at low temperatures two times larger than the in-plane one. As a consequence strong incommensurate antiferromagnetic fluctuations of the quasi-one-dimensional $xz$- and $yz$-bands point into the $z$-direction. Our results provide further evidence for the importance of spin fluctuations for triplet superconductivity in Sr$_2$RuO$_4$.Comment: revised versio

Effects of organic fertilizers on growth and yield of Roselle (Hibiscus sabdariffa L.) on BRIS soil

The application of organic fertilizers on roselle has generated much interest among the researchers and farmers for the past two decades. However, little attention is given on the plantation quality in Beach Ridges Interspersed with Swales (BRIS) soil. Roselle is generally preferred because it is rich in ascorbic acid and anthocyanin that are very beneficial for health. This study determined the growth, yields and antioxidants of roselle on BRIS soils after application with different rate of organic fertilizers. Roselle was treated with five different rates of goat manure i.e. T1 (control), T2 (40 mt/ha), T3 (80 mt/ha), T4 (120 mt/ha) and T5 (160 mt/ha). Plant growth, yields and antioxidants of roselle calyxes were determined at three weeks interval for 21 weeks. Generally, organic fertilizer treated roselle showed significant increased (p<0.05) plant growth and plant yield. Higher rate of organic fertilizer, particularly T5 (160 mt/ha) increased the stem diameter and stem height, leaves number and leaves area as well as the biomass and number of calyx. Organic fertilizer treatments had no significant effect on ascorbic acid, carotenoids and anthocyanin production except for T3 treated plants whereas, chlorophyll content was significantly induced (p<0.05) in response to organic fertilizer treatments. In conclusion, application of organic fertilizers at higher rate showed positive effects on the growth, yield and antioxidant content of roselle. Therefore, organic fertilizer should be frequently applied in the farms to get the best growth and yields of the plant

Low threshold linear cavity mode-locked fiber laser using microfiber-based carbon nanotube saturable absorber

In this work, we demonstrate a linear cavity mode-locked erbium-doped fiber laser in C-band wavelength region. The passive mode-locking is achieved using a microfiber-based carbon nanotube saturable absorber. The carbon nanotube saturable absorber has low saturation fluence of 0.98 µJ/cm2. Together with the linear cavity architecture, the fiber laser starts to produce soliton pulses at low pump power of 22.6 mW. The proposed fiber laser generates fundamental soliton pulses with a center wavelength, pulse width, and repetition rate of 1557.1 nm, 820 fs, and 5.41 MHz, respectively. This mode-locked laser scheme presents a viable option in the development of low threshold ultrashort pulse system for deployment as a seed laser

Electron correlation resonances in the transport through a single quantum level

Correlation effects in the transport properties of a single quantum level coupled to electron reservoirs are discussed theoretically using a non-equilibrium Green functions approach. Our method is based on the introduction of a second-order self-energy associated with the Coulomb interaction that consistently eliminates the pathologies found in previous perturbative calculations. We present results for the current-voltage characteristic illustrating the different correlation effects that may be found in this system, including the Kondo anomaly and Coulomb blockade. We finally discuss the experimental conditions for the simultaneous observation of these effects in an ultrasmall quantum dot.Comment: 4 pages (two columns), 3 figures under reques

Charge occupancy of two interacting electrons on artificial molecules - exact results

We present exact solutions for two interacting electrons on an artificial atom and on an artificial molecule made by one and two (single level) quantum dots connected by ideal leads. Specifically, we calculate the accumulated charge on the dots as function of the gate voltage, for various strengths of the electron-electron interaction and of the hybridization between the dots and the (one-dimensional) leads. With increasing of the (negative) gate voltage, the accumulated charge in the two-electron ground state increases in gradual steps from 0 to 1 and then to 2. The value 0 represents an "insulating" state, where both electrons are bound to shallow states on the impurities. The value of 1 corresponds to a "metal", with one electron localized on the dots and the other extended on the leads. The value of 2 corresponds to another "insulator", with both electrons strongly localized. The width of the "metallic" regime diverges with strength of the electron-electron interaction for the single dot, but remains very narrow for the double dot. These results are contrasted with the simple Coulomb blockade picture.Comment: 12 pages, 7 figure

Did high sugar-sweetened beverage purchasers respond differently to the excise tax on sugar-sweetened beverages in Mexico?

Objective To estimate changes in taxed and untaxed beverages by volume of beverage purchased after a sugar-sweetened beverage (SSB) tax was introduced in 2014 in Mexico. Design We used household purchase data from January 2012 to December 2015. We first classified the sample into four groups based on pre-tax purchases of beverages: (i) higher purchases of taxed beverages and lower purchases of untaxed beverages (HTLU-unhealthier); (ii) higher purchases of both types of beverages (HTHU); (iii) lower purchases of taxed and untaxed beverages (LTLU); and (iv) lower purchases of taxed beverages and higher purchases of untaxed beverages (LTHU-healthier). Next, we estimated differences in purchases after the tax was implemented for each group compared with a counterfactual based on pre-tax trends using a fixed-effects model. Setting Areas with more than 50 000 residents in Mexico. Participants Households (n 6089). Results The HTLU-unhealthier and HTHU groups had the largest absolute and relative reductions in taxed beverages and increased their purchases of untaxed beverages. Households with lower purchases of untaxed beverages (HTLU-unhealthier and LTLU) had the largest absolute and relative increases in untaxed beverages. We also found that among households with higher purchases of taxed beverages, the group with lowest socio-economic status had the greatest reduction in purchases of taxed beverages. Conclusions Evidence associating the SSB tax with larger reductions among high purchasers of taxed beverages prior to the tax is relevant, as higher SSB purchasers have a greater risk of obesity, diabetes and other cardiometabolic outcomes