Knitting distributed cluster state ladders with spin chains

There has been much recent study on the application of spin chains to quantum state transfer and communication. Here we discuss the utilisation of spin chains (set up for perfect quantum state transfer) for the knitting of distributed cluster state structures, between spin qubits repeatedly injected and extracted at the ends of the chain. The cluster states emerge from the natural evolution of the system across different excitation number sectors. We discuss the decohering effects of errors in the injection and extraction process as well as the effects of fabrication and random errors.Comment: To be published in PRA. v2 includes minor corrections as well as an added discussion on refocussin

Effect of perturbations on information transfer in spin chains

Spin chains have been proposed as a reliable and convenient way of transferring information and entanglement in a quantum computational context. Nonetheless, it has to be expected that any physical implementation of these systems will be subject to several perturbative factors which could potentially diminish the transfer quality. In this paper, we investigate a number of possible fabrication defects in the spin chains themselves as well as the effect of non-synchronous or imperfect input operations, with a focus on the case of multiple excitation/qubit transfer. We consider both entangled and unentangled states, and in particular the transfer of an entangled pair of adjacent spins at one end of a chain under the mirroring rule and also the creation of entanglement resulting from injection at both end spins.Comment: Journal version fixes last typo

Anderson localisation in spin chains for perfect state transfer

Abstract: Anderson localisation is an important phenomenon arising in many areas of physics, andhere we explore it in the context of quantum information devices. Finite dimensional spinchains have been demonstrated to be important devices for quantum information transport,and in particular can be engineered to allow for “perfect state transfer” (PST). Here wepresent extensive investigations of disordered PST spin chains, demonstrating spatiallocalisation and transport retardation effects, and relate these effects to conventionalAnderson localisation. We provide thresholds for Anderson localisation in these finitequantum information systems for both the spatial and the transport domains. Finally, weconsider the effect of disorder on the eigenstates and energy spectrum of our Hamiltonian,where results support our conclusions on the presence of Anderson localisation. Graphical abstract: [Figure not available: see fulltext.

Topologically protected localised states in spin chains

We consider spin chain families inspired by the Su, Schrieffer and Hegger (SSH) model. We demonstrate explicitly the topologically induced spatial localisation of quantum states in our systems. We present detailed investigations of the effects of random noise, showing that these topologically protected states are very robust against this type of perturbation. Systems with such topological robustness are clearly good candidates for quantum information tasks and we discuss some potential applications. Thus, we present interesting spin chain models which show promising applications for quantum devices

Rapid Heterotrophic Ossification with Cryopreserved Poly(ethylene glycol-) Microencapsulated BMP2-Expressing MSCs

Autologous bone grafting is the most effective treatment for long-bone nonunions, but it poses considerable risks to donors, necessitating the development of alternative therapeutics. Poly(ethylene glycol) (PEG) microencapsulation and BMP2 transgene delivery are being developed together to induce rapid bone formation. However, methods to make these treatments available for clinical applications are presently lacking. In this study we used mesenchymal stem cells (MSCs) due to their ease of harvest, replication potential, and immunomodulatory capabilities. MSCs were from sheep and pig due to their appeal as large animal models for bone nonunion. We demonstrated that cryopreservation of these microencapsulated MSCs did not affect their cell viability, adenoviral BMP2 production, or ability to initiate bone formation. Additionally, microspheres showed no appreciable damage from cryopreservation when examined with light and electron microscopy. These results validate the use of cryopreservation in preserving the viability and functionality of PEG-encapsulated BMP2-transduced MSCs

Photonic coherent state transfer with Hamiltonian dynamics

We report the observation of near-perfect light wave transfer by emulating quantum state transfer on a lattice with Hamiltonian dynamics, i.e., time-dependent intersite couplings. The structure transferring a single waveguide ex-citation over 11 sites with a fidelity of 0.93 works for classical light as well as single photons. As our implementation of perfect quantum state transfer uses a photonic setting, we introduce polarization as a new degree of freedom to the transport protocol. We demonstrate rotation operations of up to 40 ° on polarization during state transfer. © 201

Natural coagulates for wastewater treatment; a review for application and mechanism

The increase of water demand and wastewater generation is among the global concerns in the world. The less effective management of water sources leads to serious consequences, the direct disposal of untreated wastewater is associated with the environmental pollution, elimination of aquatic life and the spread of deadly epidemics. The flocculation process is one of the most important stages in water and wastewater treatment plants, wherein this phase the plankton, colloidal particles, and pollutants are precipitated and removed. Two major types of coagulants are used in the flocculation process included the chemical and natural coagulants. Many studies have been performed to optimize the flocculation process while most of these studies have confirmed the hazardous effects of chemical coagulants utilization on the ecosystem. This chapter reviews a summary of the coagulation/flocculation processes using natural coagulants as well as reviews one of the most effective natural methods of water and wastewater treatment

Methods and compositions for bone formation

A method and system to induce bone growth by locally delivering bone morphogenetic proteins (BMPs) to the target location for a prolonged period without invasive procedures are disclosed. The new bone growth is induced by delivering cells producing BMPs from transduced viral vectors to the target cite. In various embodiments, the cells are encapsulated in hydrogel microspheres that are non-degradable or degradable by enzymes produced during the bone formation process. Various embodiments may be used to induce spinal fusion or repair critical bone defects

ABCDEF Bundle Practices for Critically Ill Children: An International Survey of 161 PICUs in 18 Countries

OBJECTIVES: To evaluate current international practice in PICUs regarding components of the "Assessing Pain, Both Spontaneous Awakening and Breathing Trials, Choice of Sedation, Delirium Monitoring/Management, Early Exercise/ Mobility, and Family Engagement/Empowerment"(ABCDEF) bundle. DESIGN: Online surveys conducted between 2017 and 2019. SETTING: One-hundred sixty-one PICUs across the United States (n = 82), Canada (n = 14), Brazil (n = 27), and Europe (n = 38) participating in the Prevalence of Acute Rehabilitation for Kids in the PICU study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 161 participating PICUs, 83% were in academic teaching hospitals and 42% were in free-standing children's hospitals. Median size was 16 beds (interquartile range, 10-24 beds). Only 15 PICUs (9%) had incorporated all six ABCDEF bundle components into routine practice. Standardized pain assessment (A) was the most common (91%), followed by family engagement (F, 88%) and routine sedation assessment (C) with validated scales (84%). Protocols for testing extubation readiness or conducting spontaneous breathing trials (B) were reported in 57%, with 34% reporting a ventilator weaning protocol. Routine delirium monitoring with a validated screening tool (D) was reported by 44% of PICUs, and 26% had a guideline, protocol, or policy for early exercise/mobility (E). Practices for spontaneous breathing trials were variable in 29% of Canadian PICUs versus greater than 50% in the other regions. Delirium monitoring was lowest in Brazilian PICUs (18%) versus greater than 40% in other regions, and family engagement was reported in 55% of European PICUs versus greater than 90% in other regions. CONCLUSIONS: ABCDEF bundle components have been adopted with substantial variability across regions. Additional research must rigorously evaluate the efficacy of specific elements with a focus on B, D, E, and full ABCDEF bundle implementation. Implementation science is needed to facilitate an understanding of the barriers to ABCDEF implementation and sustainability with a focus on specific cultural and regional differences