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Nuclear magnetic resonance (NMR) spectroscopy is a powerful technique for analysing the structure and function of molecules, and for performing three-dimensional imaging of their spin densities. At the heart of NMR spectrometers is the detection of electromagnetic radiation, in the form of a free induction decay signal.sup.1, generated by nuclei precessing around an applied magnetic field. Whereas conventional NMR requires signals from 10.sup.12 or more nuclei, recent advances in sensitive magnetometry.sup.2,3 have dramatically lowered the required number of nuclei to a level where a few or even individual nuclear spins can be detected.sup.4-6. It is unclear whether continuous detection of the free induction decay can still be applied at the single-spin level, or whether quantum back-action (the effect that a detector has on the measurement itself) modifies or suppresses the NMR response. Here we report the tracking of single nuclear spin precession using periodic weak measurements.sup.7-9. Our experimental system consists of nuclear spins in diamond that are weakly interacting with the electronic spin of a nearby nitrogen vacancy centre, acting as an optically readable meter qubit. We observe and minimize two important effects of quantum back-action: measurement-induced decoherence.sup.10 and frequency synchronization with the sampling clock.sup.11,12. We use periodic weak measurements to demonstrate sensitive, high-resolution NMR spectroscopy of multiple nuclear spins with a priori unknown frequencies. Our method may provide a useful route to single-molecule NMR.sup.13,14 at atomic resolution. Periodic weak measurements of just a few carbon-13 nuclear spins in diamond demonstrate sensitive, high-resolution nuclear magnetic resonance spectroscopy at the molecular level., Author(s): K. S. Cujia [sup.1] , J. M. Boss [sup.1] , K. Herb [sup.1] , J. Zopes [sup.1] , C. L. Degen [sup.1] Author Affiliations: (1) Department of Physics, ETH [...]

One of the essential processes in Mobile Ad hoc Networks (MANETs) is blind flooding to discover routes between source and destination mobile nodes. As the density of nodes in the network increases, the number of broadcast packets increases exponentially. This can lead to broadcast storms, a drain on the device’s battery, and reduced network efficiency. We propose a Cross-layer Adaptive Fuzzy-based Ad hoc On-Demand Distance Vector routing protocol (CLAF-AODV) to minimize the routing broadcast traffic by considering the quality of service (QoS) (e.g. delay, throughput, packet loss), stability, and adaptability of the network. The suggested method employs two-level fuzzy logic and a cross-layer design approach to select the appropriate nodes with a higher probability of participating in broadcasting by considering parameters from the three first layers of the Open Systems Interconnection (OSI) model to achieve a quality of service, stability, and adaptability. It not only investigates the quality of the node and the network density around the node to make a decision but also investigates the path that the broadcast packet traveled to reach this node. Simulation results reveal that our proposed protocol reduces the number of broadcast packets and significantly improves network performance with respect to throughput, packet loss, normalized routing load, collision rate, and average energy consumption compared to the standard AODV and the Fixed Probability AODV (FP-AODV) algorithms.

Introduction: Balance loss and falls are a common and multifactorial finding in persons with Parkinson's Disease (pwPD). Objective fatigability is thought to contribute to falls in other neurologic conditions, but its impact on balance in pwPD is not known. The two-fold purpose of this study was to: 1) establish that a 6-minute walk (6MWFast) is a stimulus to subjective fatigue for pwPD; and, 2) determine if the Mini Balance Evaluation Systems Test (MBT) is sensitive to change that was induced by a fatiguing condition. Methods: Using a randomized crossover design, 19 research participants performed a Mini Balance Evaluation Systems Test (MBT) before and after either a ‘fast’ 6-minute walk (6MWFast) to induce fatigue or a 6-minute rest. Results: VASF scores increased after the 6MWFast. Total MBT scores in research participants with Modified Hoehn and Yahr (H&Y) scores of 3.0 and above differed significantly before and after the ‘fast’ 6-minute walk (p = .007, n = 9) while participants with H&Y scores of 1.5 to 2.5 (p = .084, n = 10) did not, suggesting that more disabled pwPD were more likely to experience fatigability that interfered with balance. Conclusions: A 6MWFast is a sufficient stimulus to induce subjective fatigue in pwPD and to decrease total MBT scores for more disabled pwPD. Balance evaluations should occur when pwPD are in fatigued and unfatigued states to determine whether fatigue has an impact on balance performance.

Let T be a set-valued contraction mapping on a general Banach space $\mathcal{B}$. In the first part of this paper we introduce the evolution inclusion $\dot x + x \in Tx$ and study the convergence of solutions to this inclusion toward fixed points of T. Two cases are examined: (i) T has a fixed point $\bar y \in \mathcal{B}$ in the usual sense, i.e., $\bar y = T \bar y$ and (ii) T has a fixed point in the sense of inclusions, i.e., $\bar y \in T \bar y$. In the second part we extend this analysis to the case of set-valued evolution equations taking the form $\dot x + x = Tx$. We also provide some applications to generalized fractal transforms.

We consider the inverse problem associated with IFSM: Given a target function f, find an IFSM, such that its invariant fixed point f is sufficiently close to f in the Lp distance. In this paper, we extend the collage-based method developed by Forte and Vrscay (1995) along two different directions. We first search for a set of mappings that not only minimizes the collage error but also maximizes the entropy of the dynamical system. We then include an extra term in the minimization process which takes into account the sparsity of the set of mappings. In this new formulation, the minimization of collage error is treated as multi-criteria problem: we consider three different and conflicting criteria i.e., collage error, entropy and sparsity. To solve this multi-criteria program we proceed by scalarization and we reduce the model to a single-criterion program by combining all objective functions with different trade-off weights. The results of some numerical computations are presented. Numerical studies indicate that a maximum entropy principle exists for this approximation problem, i.e., that the suboptimal solutions produced by collage coding can be improved at least slightly by adding a maximum entropy criterion.

In the theory of Iterated Function Systems (IFSs) it is known that one can find an IFS with greyscale maps (IFSM) to approximate any target signal or image with arbitrary precision, and a systematic approach for doing so was described. In this paper, we extend these ideas to the framework of random IFSM operators. We consider the situation where one has many noisy observations of a particular target signal and show that the greyscale map parameters for each individual observation inherit the noise distribution of the observation. We provide illustrative examples.

By integrating philosophical rigor with practical examples and personal history and revelation, the author shares how he ended his quest to understand the concepts of life, mind, and soul and resolved the mind-body problem. The article relates the key insight garnered from Elliott Jaques that triggered a new, internally-consistent conceptual framework or paradigm. Founded on a unitary organism model of life, it replaced the mind-body-soul model. The logic of the new conceptual framework is developed through brief, methodical discussions that juxtapose choice and judgement with calculation, Newtonian physics, randomness, and self correction. The paper is grounded in the premise that our attempts to answer a question (e.g. "How do we think and judged?") are hindered by accepting an entity (e.g. mind) whose only evidence is that the question exists. On that foundation, unitary arguments trace the author’s dissolution of concepts of mind, body, and soul and the spiritual. General implications of this framework are then applied to terminology and to the origin of life, abortion, and trading one duality for another. In relating some personal implications of this framework in daily life, the author makes the case for the value of simplicity in conceptual frameworks and the clarity that can result.

Breast-conserving surgery (BCS) is a commonly utilized treatment for early stage breast cancers but has relatively high reexcision rates due to post-surgical identification of positive margins. A fast, specific, sensitive, easy-to-use tool for assessing margins intraoperatively could reduce the need for additional surgeries, and while many techniques have been explored, the clinical need is still unmet. We assess the potential of Magnetic Particle Imaging (MPI) for intraoperative margin assessment in BCS, using a passively or actively tumor-targeted iron oxide agent and two hardware devices: a hand-held Magnetic Particle detector for identifying residual tumor in the breast, and a small-bore MPI scanner for quickly imaging the tumor distribution in the excised specimen. Here, we present both hardware systems and demonstrate proof-of-concept detection and imaging of clinically relevant phantoms.

A case is reported in which a patient developed methemoglobinemia-induced cyanosis while under general anesthesia during surgery for multiple fascial space infections. The cause of methemoglobinemia was 20% benzocaine spray used for local anesthesia before intubation. Acutely developing methemoglobinemia is infrequently encountered in clinical practice. When confronted with cyanosis in the absence of cardiac or pulmonary disease, one must seriously consider the diagnosis of methemoglobinemia. The etiology of methemoglobinemia, the causative agents, the diagnosis, and the emergency treatment required are discussed.

This study was designed to evaluate the utility of the bone markers total alkaline phosphatase (TAP), bone-specific alkaline phosphatase (BAP), aminoterminal propeptide of type I collagen (PINP), carboxyterminal propeptide of type I collagen (PICP), pyridinoline crosslinks (PYD), deoxypyridinoline crosslinks (DPD), cross-linked carboxyterminal telopeptide of type I collagen (ICTP), cross-linked carboxyterminal telopeptide of type I collagen (CTx, beta-CrossLaps) and tartrate-resistant acid phosphatase 5b (TRAP 5b) in comparison with bone scintigraphy for the diagnosis of bone metastasis in lung carcinoma patients. The study population consisted of 49 patients with bone metastasis confirmed by plain radiography and/or computed tomography, 89 patients without bone metastasis, 12 patients with benign lung diseases and 18 healthy persons. All patients were of male gender. The bone markers were measured using commercially available tests. Serum and urine were collected from fasting patients at the time of bone scan between 7.00 and 8.00 a.m. The sensitivity of bone scintigraphy was 100%, its specificity 76.4%, resulting in a diagnostic efficiency of 84.8%. The positive predictive value was calculated to be 70% and the negative one to be 100%. The concentrations of the bone markers TAP, BAP, PINP, PYD, DPD and ICTP were significantly higher in patients with bone metastasis than in those without bone metastasis (p<0.01). The levels of PICP and CTx only tended to be higher in the patients with bone metastasis compared to those without bone metastasis. There was no significant difference in the TRAP 5b levels between the two groups. There was also no difference in the marker levels between osteoblastic, osteolytic and mixed osteoblastic-osteolytic lesions. Contrary to BAP, PICP, CTx and TRAP 5b, the markers TAP, PINP, PYD, DPD and ICTP were found to be higher (p<0.01-0.05) in patients with bone metastasis than in patients with benign lung diseases. In addition, PYD, DPD and ICTP differentiated patients with benign lung diseases from the healthy controls. Based on cut-off values that correspond to 95% specificity in the group of healthy persons, the sensitivity of the marker assays were as follows (specificity in brackets): TAP 33.3% (97.5%), BAP 22% (100%), PINP 18.4% (97.5%), PICP 2.1% (95.2%), PYD 91.8% (24.1%), DPD 83.7% (34.5%), ICTP 75.5% (44.6%), CTx 45.8% (77.5%) and TRAP 5b 14% (84%). The corresponding data for the diagnostic efficiency were as follows: TAP 73.6%, BAP 77.1%, PINP 67.7%, PICP 61.1%, PYD 48.5%, DPD 55.2%, ICTP 56.1%, CTx 65.6% and TRAP 5b 58.7%, respectively. The positive predictive values ranged from 20% (PICP) to 100% (BAP) and the negative values from 62.7% (PICP) to 84% (PYD). In the ROC analysis, TAP, followed by RAP, PINP and PYD, showed the best performance. The levels of TAP, BAP, PINP, PYD, DPD and ICTP were found to be higher in the patients with bone metastasis compared to those with metastastic lesions in other sites (p<0.01, except for ICTP having a p value of < 0.05). The levels of TAP, BAP, PYD, DPD and ICTP increased significantly with the number of metastases. There was also a steady increase in T scores of the markers PINP, PYD, DPD and ICTP with the extent of the metastatic bone disease. It is concluded that the currently available bone markers cannot replace bone scintigraphy, either for screening or in the diagnosis of bone metastasis, in lung carcinoma patients. However, a panel consisting of TAP, BAP, PINP, PYD, DPD and ICTP may be of some value as an adjunct tool to bone scintigraphy for this purpose.