Observable quantum entanglement due to gravity

No experiment to date has provided evidence for quantum features of the gravitational interaction. Recently proposed tests suggest looking for the generation of quantum entanglement between massive objects as a possible route towards the observation of such features. Motivated by advances in optical cooling of mirrors, here we provide a systematic study of entanglement between two masses that are coupled gravitationally. We first consider the masses trapped at all times in harmonic potentials (optomechanics) and then the masses released from the traps. This leads to the estimate of the experimental parameters required for the observation of gravitationally induced entanglement. The optomechanical setup demands LIGO-like mirrors and squeezing or long coherence times, but the released masses can be light and accumulate detectable entanglement in a timescale shorter than their coherence times. No macroscopic quantum superposition develops during the evolution. We discuss the implications from such thought experiments regarding the nature of the gravitational coupling

Attenuation in Rectangular Waveguides with Finite Conductivity Walls

We present a fundamental and accurate approach to compute the attenuation of electromagnetic waves propagating in rectangular waveguides with finite conductivity walls. The wavenumbers kx and ky in the x and y directions respectively, are obtained as roots of a set of transcendental equations derived by matching the tangential component of the electric field (E) and the magnetic field (H) at the surface of the waveguide walls. The electrical properties of the wall material are determined by the complex permittivity ε, permeability μ, and conductivity σ. We have examined the validity of our model by carrying out measurements on the loss arising from the fundamental TE10 mode near the cutoff frequency. We also found good agreement between our results and those obtained by others including Papadopoulos’ perturbation method across a wide range of frequencies, in particular in the vicinity of cutoff. In the presence of degenerate modes however, our method gives higher losses, which we attribute to the coupling between modes as a result of dispersion

Controlled Wetting Test of a Soil Nailed Loose Fill Slope: Case Study

For an in-depth understanding of the failure mechanism of loose fill slopes and the strengthening effect by soil nails, a comprehensive field study program has been carried out at a specially built slope. The test slope was constructed by end-tipping of completely decomposed granitic soils almost without any compaction. The controlled failure test program was mainly composed of surcharge at the crest, wetting with surcharge, and wetting without surcharge. This paper is aimed at a case study of the coupled hydro-mechanical response of the test slope during the recharge process with surcharge. Through a comprehensive instrumentation system, abundant monitoring data with regards to the complex performance of the loose fill and soil nails were collected. It was found that redistribution of water content within the loose fill was well consistent with the recharge program, and nonlinear deformation developed significantly in the loose fill by the reduction of shear strength due to increased pore pressure and diminished suction when subjected to large wetting loads. Also a two-dimensional simplified finite element model is established and some preliminary simulation results are presented

Exploring Access and Equity in Malaysia’s Private Higher Education

Private higher education institutions (PrHEIs) are utilized to complement public provision due to financial constraints faced in public provision. However, increasing private provision has raised interesting questions as to who gets educated in these PrHEIs. Is increasing private supply enlarging the circle of opportunity to reach those who might otherwise have been unable to enter university or college? In other words, has the explosion in private supply translated into greater inclusion or increased exclusion? This paper explores the access and equity issues in Malaysia's private higher education system. Malaysia is an interesting case study due to the significant presence of PrHEIs in the country and their contribution toward student enrolment. The findings show that the Malaysian government has provided considerable financial support for the development of PrHEIs, through the provision of incentives, subsidized loans, and scholarships. Quality assurance efforts further enhance the development of private provision, as student loans and scholarships are only provided for students on accredited programs. Therefore, PrHEIs have widened access and equity, with the help of government support. Despite this, Malaysia's model of providing access and equity through private provision may be unsustainable, due to the poor repayment record of student loans and the economic need to reduce the fiscal deficit of the government

Empowering Non-Terrestrial Networks with Artificial Intelligence: A Survey

6G networks can support global, ubiquitous and seamless connectivity through the convergence of terrestrial and non-terrestrial networks (NTNs). Unlike terrestrial scenarios, NTNs pose unique challenges including propagation characteristics, latency and mobility, owing to the operations in spaceborne and airborne platforms. To overcome all these technical hurdles, this survey paper presents the use of artificial intelligence (AI) techniques in learning and adapting to the complex NTN environments. We begin by providing an overview of NTNs in the context of 6G, highlighting the potential security and privacy issues. Next, we review the existing AI methods adopted for 6G NTN optimization, starting from machine learning (ML), through deep learning (DL) to deep reinforcement learning (DRL). All these AI techniques have paved the way towards more intelligent network planning, resource allocation (RA), and interference management. Furthermore, we discuss the challenges and opportunities in AI-powered NTN for 6G networks. Finally, we conclude by providing insights and recommendations on the key enabling technologies for future AI-powered 6G NTNs

Requirements for improving health and well-being of children with Prader-Willi syndrome and their families

Prader-Willi syndrome (PWS) is a rare genetic condition with multi-system involvement. The literature was reviewed to describe neurodevelopment and the behavioural phenotype, endocrine and metabolic disorders and respiratory and sleep functioning. Implications for child and family quality of life were explored. Challenging behaviours contribute to poorer well-being and quality of life for both the child and caregiver. Recent evidence indicates healthy outcomes of weight and height can be achieved with growth hormone therapy and dietary restriction and should be the current target for all individuals with PWS. Gaps in the literature included therapies to manage challenging behaviours, as well as understanding the effects of growth hormone on respiratory and sleep function. New knowledge regarding the transition of children and families from schooling and paediatric health services to employment, accommodation and adult health services is also needed. Developing a national population-based registry could address these knowledge gaps and inform advocacy for support services that improve the well-being of individuals with PWS and their families

Female trauma patients in the emergency department: should their injury prevention programme be different?

Background: (1) To compare the characteristics of female and male trauma patients seen in the Emergency Department (ED) and (2) to determine if injury prevention programmes for women should be different. Methods: A prospective survey was conducted for 11544 trauma patients, aged 15 years and above, who presented to the ED of an urban public hospital in Singapore over 6 months. The following data were collected: demography, place, type and mechanism of injury and subsequent disposition from the ED. Results: Almost half (49.5%) the injuries sustained by females occurred at home, with low falls of less than 2 metres being the most common mechanism of injury (52.7%). Victims of domestic violence were predominantly female at p<0.0001

Sequential and compartmentalized action of Rabs, SNAREs, and MAL in the apical delivery of fusiform vesicles in urothelial umbrella cells

Uroplakins (UPs) are major differentiation products of urothelial umbrella cells and play important roles in forming the permeability barrier and in the expansion/stabilization of the apical membrane. Further, UPIa serves as a uropathogenic Escherichia coli receptor. Although it is understood that UPs are delivered to the apical membrane via fusiform vesicles (FVs), the mechanisms that regulate this exocytic pathway remain poorly understood. Immunomicroscopy of normal and mutant mouse urothelia show that the UP-delivering FVs contained Rab8/11 and Rab27b/Slac2-a, which mediate apical transport along actin filaments. Subsequently a Rab27b/Slp2-a complex mediated FV–membrane anchorage before SNARE-mediated and MAL-facilitated apical fusion. We also show that keratin 20 (K20), which forms a chicken-wire network ∼200 nm below the apical membrane and has hole sizes allowing FV passage, defines a subapical compartment containing FVs primed and strategically located for fusion. Finally, we show that Rab8/11 and Rab27b function in the same pathway, Rab27b knockout leads to uroplakin and Slp2-a destabilization, and Rab27b works upstream from MAL. These data support a unifying model in which UP cargoes are targeted for apical insertion via sequential interactions with Rabs and their effectors, SNAREs and MAL, and in which K20 plays a key role in regulating vesicular trafficking