Coherent Patterning of Matter Waves with Subwavelength Localization

We propose the Subwavelength Localization via Adiabatic Passage (SLAP) technique to coherently achieve state-selective patterning of matter waves well beyond the diffraction limit. The SLAP technique consists in coupling two partially overlapping and spatially structured laser fields to three internal levels of the matter wave yielding state-selective localization at those positions where the adiabatic passage process does not occur. We show that by means of this technique matter wave localization down to the single nanometer scale can be achieved. We analyze in detail the potential implementation of the SLAP technique for nano-lithography with an atomic beam of metastable Ne* and for coherent patterning of a two-component 87Rb Bose-Einstein condensate.Comment: 6 pages, 5 figure

Space vector PWM technique for a three-level six-phase drive

A space vector pulse-width modulation (SVPWM) strategy for a three-level six-phase drive based on vector space decomposition (VSD) approach is presented for the first time in this paper. The steps, requirements and conditions in determining the right switching sequences for the proposed modulation strategy are explained in detail. The developed SVPWM strategy is then simulated in Matlab/Simulink while driving a symmetrical six-phase induction machine running at no load. Obtained results prove the validity of the algorithm

A space vector PWM technique for a three-level symmetrical six phase drive

A space vector pulse-width modulation (SVPWM) algorithm for a three-level symmetrical six-phase drive, based on vector space decomposition (VSD) approach, is for the first time presented and experimentally proven in this paper. The process how to correctly select the optimal switching sequences, based on several starting requirements and conditions for the analysed topology, such that the output phase voltage waveforms do not contain any low order harmonics, is explained in detail. The developed SVPWM algorithm is verified experimentally using a three-level neutral-point-clamped (NPC) converter and a symmetrical six-phase induction machine. Obtained results prove the validity of the developed SVPWM algorithm. The performance of the SVPWM algorithm is compared with the corresponding carrier-based modulation strategy and it is shown that the two techniques yield identical performance. Finally, both simulation and experimental analysis of the voltage and current THD are reported

Space Vector PWM Technique for a Three-level Asymmetrical Six-phase Drive

A space vector pulse-width modulation (SVPWM) strategy for a three-level asymmetrical six-phase drive, with a single neutral point, based on vector space decomposition (VSD) approach is presented for the first time in this paper. The selection process, related to the determination of the right switching sequences for the proposed modulation strategy, is discussed in detail. The developed SVPWM strategy is then simulated in PLECS simulation package, while driving an asymmetrical six-phase induction machine running at no load. Obtained results prove the validity of the algorithm

Evaluation of physical and ultra-structural attributes of bulls' semen with variable freezing potential

This experiment was conducted to determine the physical and ultra-structural attributes of fresh bull semen and assess their potential use for freezing and AI. A total of 40 semen samples collected from 4 mature bulls (10 samples per bull) were analyzed. The semen samples were examined for colour, volume, concentration, pH, general and progressive motilities, morphologically normal spermatozoa, acrosome and DNA damage, and lipid peroxidation. Transmission Electron Microscopy (TEM) was also performed to evaluate the ultra-structures of the spermatozoa. Results showed the semen colour varied from bull to bull from creamy-white in bull #1, to milky in bulls #2 and 4, then cloudy in bull #3. Highest sperm concentration, lipid peroxidation and pH were recorded from bull #4. Highest volume, progressive motility, morphology, less acrosome damage and viability were from bull #2. While best values for general motility and DNA damage were obtained from bull #1. TEM revealed 92.5, 90.0 and 82% of intact heads for bulls #1, 2 and 3, respectively, much higher than 62.5% for bull #4 and 32.5, 25.0, 37.5% of total defective spermatozoa for bulls #1, 2 and 3, respectively, much better than 80.0% in bull #4. Conclusively, bulls #1, 2 and 3 were consistently satisfactory in most parameters evaluated and hence their semen can be used for freezing. On the other hand, bull #4 expressed higher (p<0.05) sperm concentration but yet was unsatisfactory in most other parameters assessed, including low live:dead ratio and high percentage of abnormalities recorded, manifesting poor potential of freezability

Butylated hydroxytoluene can reduce oxidative stress and improve quality of frozenthawed bull semen processed in lecithin and egg yolk based extenders

The aims of this study were to evaluate the effects of anti-oxidant butylated hydroxytoluene (BHT), when added at different concentrations into lecithin-based Bioxcell® (BX) and two egg-yolk-based; Tris (TY) and citrate (CE) semen extenders, on post-thaw bull sperm quality and oxidative stress. A total of 30 ejaculates from three bulls were collected using an electro ejaculator. Ejaculates were extended with one of the BX, TY and CE extenders, which contained different concentrations (0.0 – control, 0.5, 1.0, 1.5, 2.0 and 3.0 mM/ml) of BHT. The extended semen samples were chilled to 4 °C, and then frozen slowly to −196 °C in 0.25 ml straws before being stored in liquid nitrogen for 2 weeks. Results showed that supplementation of BHT improved (P < 0.05) general motility, progressive motility, morphology, acrosome integrity, DNA integrity and malondialdehyde of sperm at 0.5 mM/ml for BX and at 1–1.5 mM/ml of BHT for TY and CE when compared with the control. However, greater concentrations of 2.0 and 3.0 mM/ml of BHT had a detrimental (P < 0.05) effect compared with the control with all extenders evaluated. In conclusion, BHT supplementation at lesser concentrations (0.5–1.5 mM/ml) could improve frozen–thawed bull sperm quality by reducing oxidative stress produced during the freezing–thawing procedures in either lecithin or egg-yolk based extenders

THREE-DIMENSIONAL RECORDING AND PHOTOREALISTIC MODEL RECONSTRUCTION FOR VIRTUAL MUSEUM APPLICATION – AN EXPERIENCE IN MALAYSIA

In recent years, museums are utilizing the ability of virtual reality (VR) technologies to visualize their collections in three-dimensional (3D) environment. The demands for 3D digitization of cultural heritage have increase greatly to facilitate the development of virtual museum. Among the available techniques, the use of laser scanning for digital recording and 3D reproduction of the heritage sites and archaeological artefacts are technically more reliable due to its rapid and high resolution data capture. However, the suitable 3D laser scanners used greatly depend on the level of details and size of an object. This research used medium and close-range type of laser scanners to digitally record the heritage objects. The aim of this research was to develop methodology framework for digital recording and 3D reproduction of archaeological artefact and heritage sites in Malaysia by using terrestrial laser scanning technology. Besides, this research focused on the reconstruction of photorealistic 3D models based on the colour information yield by close-range photogrammetry. The colour descriptions were obtained either by built-in camera or externally integrated camera on the laser scanner. For better colour descriptions, external images were captured by independent Nikon D300s digital camera. The geometric model accuracy of A’Famosa and terracotta Buddha statuette was in 5&thinsp;mm and 0.41&thinsp;mm respectively. 3D flythrough animation was rendered by using the coloured point clouds model. The development of 3D Virtual Walkthrough Museum (3DVWM) utilized the 3D PDF document and SCENE WebShare platform to offer realistic visualization experience to the visitors where the reality-based models could be manipulate in 3D geometric aspects and use of metric analysis. Thus, 3DVWM can facilitate the virtual museum application in Malaysia and enable wider visitors to virtually appreciate the cultural heritage in Malaysia. Thus, this indirectly stimulates the tourism industry in our country

Optimal antiplatelet strategy after transcatheter aortic valve implantation: a meta-analysis

Objective International guidelines recommend the use of dual antiplatelet therapy (DAPT) after transcatheter aortic valve implantation (TAVI). The recommended duration of DAPT varies between guidelines. In this two-part study, we (1) performed a structured survey of 45 TAVI centres from around the world to determine if there is consensus among clinicians regarding antiplatelet therapy after TAVI; and then (2) performed a systematic review of all suitable studies (randomised controlled trials (RCTs) and registries) to determine if aspirin monotherapy can be used instead of DAPT. Methods A structured electronic survey regarding antiplatelet use after TAVI was completed by 45 TAVI centres across Europe, Australasia and the USA. A systematic review of TAVI RCTs and registries was then performed comparing DAPT duration and incidence of stroke, bleeding and death. A variance weighted least squared metaregression was then performed to determine the relationship of antiplatelet therapy and adverse events. Results 82.2% of centres routinely used DAPT after TAVI. Median duration was 3 months. 13.3% based their practice on guidelines. 11 781 patients (26 studies) were eligible for the metaregression. There was no benefit of DAPT over aspirin monotherapy for stroke (P=0.49), death (P=0.72) or bleeding (P=0.91). Discussion Aspirin monotherapy appears to be as safe and effective as DAPT after TAVI

Isoprene hotspots at the Western Coast of Antarctic Peninsula during MASEC′16

Isoprene (C5H8) plays an important role in the formation of surface ozone (O3) and the secondary organic aerosol (SOA) which contributed to the climate change. This study aims to determine hourly distribution of tropospheric isoprene over the Western Coast of Antarctic Peninsula (WCAP) during the Malaysian Antarctic Scientific Expedition Cruise 2016 (MASEC′16). In-situ measurements of isoprene were taken using a custom-built gas chromatography with photoionization detector, known as iDirac. Biological parameters such as chlorophyll a (chl-a) and particulate organic carbon (POC) were compared to the in-situ isoprene measurements. Significant positive correlation was observed between isoprene and POC concentrations (r2 = 0.67, p < 0.001), but not between isoprene and chl-a. The hotspots of isoprene over maritime Antarctic were then were investigated using NAME dispersion model reanalysis. Measurements showed that isoprene mixing ratio were the highest over region of King George Island, Deception Island and Booth Island with values of ∼5.0, ∼0.9 and ∼5.2 ppb, respectively. Backward trajectory analysis showed that air masses may have lifted the isoprene emitted by marine algae. We believe our findings provide valuable data set of isoprene estimation over the under sampled WCAP

What is ‘anti’ about anti-reaches? Reference frames selectively affect reaction times and endpoint variability

Reach movement planning involves the representation of spatial target information in different reference frames. Neurons at parietal and premotor stages of the cortical sensorimotor system represent target information in eye- or hand-centered reference frames, respectively. How the different neuronal representations affect behavioral parameters of motor planning and control, i.e. which stage of neural representation is relevant for which aspect of behavior, is not obvious from the physiology. Here, we test with a behavioral experiment if different kinematic movement parameters are affected to a different degree by either an eye- or hand-reference frame. We used a generalized anti-reach task to test the influence of stimulus-response compatibility (SRC) in eye- and hand-reference frames on reach reaction times, movement times, and endpoint variability. While in a standard anti-reach task, the SRC is identical in the eye- and hand-reference frames, we could separate SRC for the two reference frames. We found that reaction times were influenced by the SRC in eye- and hand-reference frame. In contrast, movement times were only influenced by the SRC in hand-reference frame, and endpoint variability was only influenced by the SRC in eye-reference frame. Since movement time and endpoint variability are the result of planning and control processes, while reaction times are consequences of only the planning process, we suggest that SRC effects on reaction times are highly suited to investigate reference frames of movement planning, and that eye- and hand-reference frames have distinct effects on different phases of motor action and different kinematic movement parameters