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The mechanisms that mediate the effects of 2,5-anhydro-D-mannitol (2,5-AM) on hepatocyte adenosine 3',5'-triphosphate (ATP) levels were analyzed in isolated mouse and rat liver cells based on a superfused liver slice method. Analysis of membrane potentials in superfused murine and rodent liver slices indicated the role of 2,5-AM in hyperpolarizing the hepatocyte cell membrane, reducing ATP levels and glucose production. Furthermore, 2,5-AM increased feeding by acting on metabolic sensors located in the hepatoportal area.

The projected completion of the Metro Muni Turnback (MMT) project in Sept. 1996 will alleviate the problems related to increased ridership in San Francisco's public transit system. Since the project started in Sept. 1993, new tunnels have been excavated for the underground switching and storage of MMT trains. Project completion has been hampered by wood pilings, debris, underground utilities, and existing tunnels present along the route of the MMT tunnel. Twin steel-lined tunnels were chosen for the soil type in the construction area.

We consider the problem of estimating a probability distribution that maximizes the entropy while satisfying a finite number of moment constraints, possibly corrupted by noise. Based on duality of convex programming, we present a novel approximation scheme using a smoothed fast gradient method that is equipped with explicit bounds on the approximation error. We further demonstrate how the presented scheme can be used for approximating the chemical master equation through the zero-information moment closure method, and for an approximate dynamic programming approach in the context of constrained Markov decision processes with uncountable state and action spaces. [ABSTRACT FROM AUTHOR]

Degradable quantum channels are an important class of completely positive trace-preserving maps. Among other properties, they offer a single-letter formula for the quantum and the private classical capacity and are characterized by the fact that a complementary channel can be obtained from the channel by applying a degrading channel. In this paper, we introduce the concept of approximate degradable channels, which satisfy this condition up to some finite $\varepsilon \geq 0$ . That is, there exists a degrading channel which upon composition with the channel is $\varepsilon $ -close in the diamond norm to the complementary channel. We show that for any fixed channel the smallest such $\varepsilon $ can be efficiently determined via a semidefinite program. Moreover, these approximate degradable channels also approximately inherit all other properties of degradable channels. As an application, we derive improved upper bounds to the quantum and private classical capacity for certain channels of interest in quantum communication. [ABSTRACT FROM AUTHOR]

Quantum generalizations of Rényi’s entropies are a useful tool to describe a variety of operational tasks in quantum information processing. Two families of such generalizations turn out to be particularly useful: the Petz quantum Rényi divergence \overline D\alpha and the minimal quantum Rényi divergence \widetilde D\alpha . In this paper, we prove a reverse Araki–Lieb–Thirring inequality that implies a new relation between these two families of divergences, namely, \alpha \overline D\alpha ( \varrho \| \sigma ) \leq \widetilde D\alpha ( \varrho \| \sigma ) for \alpha \in [0,1] and where $ \varrho $ and $\sigma $ are density operators. This bound suggests defining a ”pretty good fidelity,” whose relation to the usual fidelity implies the known relations between the optimal and pretty good measurement as well as the optimal and pretty good singlet fraction. We also find a new necessary and sufficient condition for optimality of the pretty good measurement and singlet fraction. [ABSTRACT FROM AUTHOR]

The quantum relative entropy between two states satisfies a monotonicity property meaning that applying the same quantum channel to both states can never increase their relative entropy. It is known that this inequality is only tight when there is a recovery map that exactly reverses the effects of the quantum channel on both states. In this paper, we strengthen this inequality by showing that the difference of relative entropies is bounded below by the measured relative entropy between the first state and a recovered state from its processed version. The recovery map is a convex combination of rotated Petz recovery maps and perfectly reverses the quantum channel on the second state. As a special case, we reproduce recent lower bounds on the conditional mutual information, such as the one proved by Fawzi and Renner. Our proof only relies on the elementary properties of pinching maps and the operator logarithm. [ABSTRACT FROM AUTHOR]

Arkan’s polar coding technique is based on the idea of synthesizing $n$ channels from the $n$ instances of the physical channel by a simple linear encoding transformation. Each synthesized channel corresponds to a particular input to the encoder. For large $n$, the synthesized channels become either essentially noiseless or almost perfectly noisy, but in total carry as much information as the original $n$ channels. Capacity can therefore be achieved by transmitting messages over the essentially noiseless synthesized channels. Unfortunately, the set of inputs corresponding to reliable synthesized channels is poorly understood, in particular, how the set depends on the underlying physical channel. In this work, we present two analytic conditions sufficient to determine if the reliable inputs corresponding to different discrete memoryless channels are aligned or not, i.e., if one set is contained in the other. Understanding the alignment of the polarized sets is important as it is directly related to universality properties of the induced polar codes, which are essential in particular for network coding problems. We demonstrate the performance of our conditions on a few examples for wiretap and broadcast channels. Finally, we show that these conditions imply that the simple quantum polar coding scheme of Renes et al. [Phys. Rev. Lett., 109, 050504, 2012] requires entanglement assistance for general channels, but also show such assistance to be unnecessary in many cases of interest. [ABSTRACT FROM AUTHOR]

We propose an iterative method for approximating the capacity of classical-quantum channels with a discrete input alphabet and a finite-dimensional output under additional constraints on the input distribution. Based on duality of convex programming, we derive explicit upper and lower bounds for the capacity. To provide an additive \varepsilon -close estimate to the capacity, the presented algorithm requires O((N \vee M) M^{3} \log (N)^{1/2} \varepsilon ^{-1}) steps, where N$ denotes the input alphabet size and $M$ denotes the output dimension. We then generalize the method to the task of approximating the capacity of classical-quantum channels with a bounded continuous input alphabet and a finite-dimensional output. This, using the idea of a universal encoder, allows us to approximate the Holevo capacity for channels with a finite-dimensional quantum mechanical input and output. In particular, we show that the problem of approximating the Holevo capacity can be reduced to a multi-dimensional integration problem. For certain families of quantum channels, we prove that the complexity to derive an additive $\varepsilon $ -close solution to the Holevo capacity is subexponential or even polynomial in the problem size. We provide several examples to illustrate the performance of the approximation scheme in practice. [ABSTRACT FROM PUBLISHER]

We construct an explicit quantum coding scheme which achieves a communication rate not less than the coherent information when used to transmit the quantum information over a noisy quantum channel. For Pauli and erasure channels, we also present efficient encoding and decoding algorithms for this communication scheme based on polar codes (essentially linear in the blocklength), but which do not require the sender and receiver to share any entanglement before the protocol begins. Due to the existence of degeneracies in the involved error-correcting codes, it is indeed possible that the rate of the scheme exceeds the coherent information. We provide a simple criterion which indicates such performance. Finally, we discuss how the scheme can be used for secret key distillation as well as private channel coding. [ABSTRACT FROM PUBLISHER]

We propose an iterative method for approximately computing the capacity of discrete memoryless channels, possibly under additional constraints on the input distribution. Based on duality of convex programming, we derive explicit upper and lower bounds for the capacity. The presented method requires O(M^2 N \sqrt \log N/\varepsilon ) to provide an estimate of the capacity to within $\varepsilon $ , where $N$ and $M$ denote the input and output alphabet size; a single iteration has a complexity $O(M N)$ . We also show how to approximately compute the capacity of memoryless channels having a bounded continuous input alphabet and a countable output alphabet under some mild assumptions on the decay rate of the channel’s tail. It is shown that discrete-time Poisson channels fall into this problem class. As an example, we compute sharp upper and lower bounds for the capacity of a discrete-time Poisson channel with a peak-power input constraint. [ABSTRACT FROM AUTHOR]

The technical challenges and prospects for the next generation high energy physics colliders are discussed.

In the CNS, receptor recycling is critical for synaptic plasticity; however, the recycling of receptors has never been observed at peripheral synapses. Using a novel imaging technique, we show here that nicotinic acetylcholine receptors (AChRs) recycle into the postsynaptic membrane of the neuromuscular junction. By sequentially labeling AChRs with biotin- bungarotoxin and streptavidin-fluorophore conjugates, we were able to distinguish recycled, preexisting, and new receptor pools at synapses in living mice. Time-lapse imaging revealed that recycled AChRs were incorporated into the synapse within hours of initial labeling, and their numbers increased with time. At fully functional synapses, AChR recycling was robust and comparable in magnitude with the insertion of newly synthesized receptors, whereas chronic synaptic activity blockade nearly abolished receptor recycling. Finally, using the same sequential labeling method, we found that acetylcholinesterase, another synaptic component, does not recycle. These results identify an activity-dependent AChR-recycling mechanism that enables the regulation of receptor density, which could lead to rapid alterations in synaptic efficacy. [ABSTRACT FROM AUTHOR]

Explores the historical relationship of the science of high energy particle (HEP) physics to the technology of superconductors. Association of high energy physics and superconductivity; Application of the NbTi technology; Next generation of HEP machines.

The endoplasmic reticulum (ER) is an extensive organelle in neurons with important roles at synapses including the regulation of cytosolic Ca2+, neurotransmission, lipid metabolism, and membrane trafficking. Despite intriguing evidence for these crucial functions, how the presynaptic ER influences synaptic physiology remains enigmatic. To gain insight into this question, we have generated and characterized mutations in the single extended synaptotagmin (Esyt) ortholog in Drosophila melanogaster. Esyts are evolutionarily conserved ER proteins with Ca2+-sensing domains that have recently been shown to orchestrate membrane tethering and lipid exchange between the ER and plasma membrane. We first demonstrate that Esyt localizes to presynaptic ER structures at the neuromuscular junction. Next, we show that synaptic growth, structure, and homeostatic plasticity are surprisingly unperturbed at synapses lacking Esyt expression. However, neurotransmission is reduced in Esyt mutants, consistent with a presynaptic role in promoting neurotransmitter release. Finally, neuronal overexpression of Esyt enhances synaptic growth and the sustainment of the vesicle pool during intense activity, suggesting that increased Esyt levels may modulate the membrane trafficking and/or resting Ca2+ pathways that control synapse extension. Thus, we identify Esyt as a presynaptic ER protein that can promote neurotransmission and synaptic growth, revealing the first in vivo neuronal functions of this conserved gene family. [ABSTRACT FROM AUTHOR]

In this study, the effect of feeding frequency and its interaction with crystalline methionine supplementation level on performance, digestion, energy and nitrogen balances was assessed. The experiment had a 2 × 4 factorial design, testing two levels of crystalline methionine (Met) and four feeding frequencies. The two diets contained Met either just fulfilling or exceeding the Met requirement of African catfish (Clarias gariepinus). African catfish with initial mean weight of 44 g were allocated to one of four feeding frequencies (six, two, one time (s) per day and two times out of three days) in a recirculation aquaculture system. Fish were fed an equal daily ration for 32 days. Performance parameters, nutrient digestibility, body composition, and nutrient balances were evaluated. Except for digestible nitrogen intake and dry matter body content, none of tested parameters was affected by the interaction between dietary Met levels and feeding frequencies. Growth, energy and nitrogen gain were unaffected by feeding frequency as well as dietary Met level. FCR was low, being 0.84 averaged over all treatments. However, feeding frequency affected feed intake and the apparent digestibility coefficient (ADC) of nutrients. Feeding at lowest frequency was accompanied by a lower feed consumption compared to other frequencies (P < 0.001). At higher frequency, ADC was higher for macronutrients but lower for phosphorus and magnesium. It was concluded that the asynchronous availability of AA for protein synthesis, which is often suggested to cause a sub-optimal utilization of crystalline AA, was not influenced by feeding frequency. However, feeding at a low frequency hampered daily feed intake of African catfish. Whereas, higher frequency improved nutrient digestibility, though it did not result in improved growth probably due to the higher energy required for maintenance related to physical activities at higher frequency. • Low feeding frequency reduced feed intake in African catfish. • Utilization efficiency of free amino acids is unaffected by feeding frequency. • Nutrient digestibility increased with feeding frequency in African catfish. [ABSTRACT FROM AUTHOR]

The chain rule for the classical relative entropy ensures that the relative entropy between probability distributions on multipartite systems can be decomposed into a sum of relative entropies of suitably chosen conditional distributions on the individual systems. Here, we prove a chain rule inequality for the quantum relative entropy. The new chain rule allows us to solve an open problem in the context of asymptotic quantum channel discrimination: surprisingly, adaptive protocols cannot improve the error rate for asymmetric channel discrimination compared to nonadaptive strategies. [ABSTRACT FROM AUTHOR]

Granulomatosis with polyangiitis (GPA) is a rare type of small to medium vessel necrotizing vasculitis that usually affects vessels of the upper or lower airways and kidneys. Cardiac involvement in GPA is often subclinical and if clinically significant has been rarely reported, even less so as an initial presentation. We describe the case of a 44-year-old man who presented with what appeared to be inferior ST-segment elevation myocardial infarction and was found to have small vessel vasculitis of the coronary arteries with associated myocarditis as a presenting manifestation of GPA, which was ultimately treated with steroids, rituximab, and avacopan., Competing Interests: The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2024 The Authors.)

Background Anti-vascular endothelial growth factor (VEGF) injections have been successful in reducing vision loss from neovascular age-related macular degeneration, a leading cause of blindness. Due to the high treatment burden and suboptimal responses, switching to bi-specific faricimab treatment may lead to improved outcomes. Methods This retrospective chart review evaluated if suboptimal responders to anti-VEGF injections had better outcomes when switched to faricimab. Suboptimal responders were defined as patients with a history of >3 months of injections and the presence of fluid after ≥3 injections. The primary endpoints were best-corrected visual acuity, treatment interval, and fluid levels. Visual acuity measurements and optical coherence tomography were performed before each injection. The total fluid area (TFA) was measured using MATLAB 2023a (MathWorks, Natick, MA, USA). Results Nineteen eyes were included in the analysis. After three faricimab injections, average letters increased from 54.5 to 59.0 (SD: 15.3; p<0.05), and the injection interval was extended from 7.6 to 9.3 weeks (SD: 3.9; p<0.01) after four injections. Patients also experienced anatomical retinal changes, with a reduction in the TFA to 47.3% (p<0.005) after the second injection and a reduction in pigment epithelial detachment height to 82.3% (p<0.005) after one injection. The central subfield thickness was significantly reduced after the second injection (90.6% (SD: 17.6%)   p<0.05). Conclusion Switching to faricimab after a suboptimal anti-VEGF response results in improvements in visual acuity, reduced treatment burden, and reduced fluid levels., Competing Interests: The authors have declared financial relationships, which are detailed in the next section., (Copyright © 2024, Sutter et al.)

Background: Left atrial (LA) enlargement is a marker of increased risk in the general population undergoing stress echocardiography. African American (AA) patients with hypertension are known to have less atrial remodeling than whites with hypertension. The prognostic impact of LA enlargement in AA with hypertension undergoing stress echocardiography is uncertain., Aim: To investigate the prognostic value of LA size in hypertensive AA patients undergoing stress echocardiography., Methods: This retrospective outcomes study enrolled 583 consecutive hypertensive AA patients who underwent stress echocardiography over a 2.5-year period. Clinical characteristics including cardiovascular risk factors, stress and echocardiographic data were collected from the electronic health record of a large community hospital. Treadmill exercise and Dobutamine protocols were conducted based on standard practices. Patients were followed for all-cause mortality. The optimal cutoff value of antero-posterior LA diameter for mortality was assessed by receiver operating characteristic analysis. Cox regression was used to determine variables associated with outcome., Results: The mean age was 57 ± 12 years. LA dilatation was present in 9% (54) of patients (LA anteroposterior ≥ 2.4 cm/m 2 ). There were 85 deaths (15%) during 4.5 ± 1.7 years of follow-up. LA diameter indexed for body surface area had an area under the curve of 0.72 ± 0.03 (optimal cut-point of 2.05 cm/m 2 ). Variables independently associated with mortality included age [ P = 0.004, hazard ratio (HR) 1.34 (1.10-1.64)], tobacco use [ P = 0.001, HR 2.59 (1.51-4.44)], left ventricular hypertrophy [ P = 0.001 , HR 2.14 (1.35-3.39)], Dobutamine stress [ P = 0.003, HR 2.12 (1.29-3.47)], heart failure history [ P = 0.031, HR 1.76 (1.05-2.94)], LA diameter ≥ 2.05 cm/m 2 [ P = 0.027, HR 1.73 (1.06-2.82)], and an abnormal stress echocardiogram [ P = 0.033, HR 1.67 (1.04-2.68)]. LA diameter as a continuous variable was also independently associated with mortality but LA size ≥ 2.40 cm/m 2 was not., Conclusion: LA enlargement is infrequent in hypertensive AA patients when traditional reference values are used. LA enlargement is independently associated with mortality when a lower than "normal" threshold (≥ 2.05 cm/m 2 ) is used., Competing Interests: Conflict-of-interest statement: The authors have nothing to disclose., (©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.)

The Eastin-Knill theorem states that no quantum error-correcting code can have a universal set of transversal gates. For Calderbank-Shor-Steane codes that can implement Clifford gates transversally, it suffices to provide one additional non-Clifford gate, such as the T gate, to achieve universality. Common methods to implement fault-tolerant T gates, e.g., magic state distillation, generate a significant hardware overhead that will likely prevent their practical usage in the near-term future. Recently, methods have been developed to mitigate the effect of noise in shallow quantum circuits that are not protected by error correction. Error mitigation methods require no additional hardware resources but suffer from a bad asymptotic scaling and apply only to a restricted class of quantum algorithms. In this Letter, we combine both approaches and show how to implement encoded Clifford+T circuits where Clifford gates are protected from noise by error correction while errors introduced by noisy encoded T gates are mitigated using the quasiprobability method. As a result, Clifford+T circuits with a number of T gates inversely proportional to the physical noise rate can be implemented on small error-corrected devices without magic state distillation. We argue that such circuits can be out of reach for state-of-the-art classical simulation algorithms.

The chain rule for the classical relative entropy ensures that the relative entropy between probability distributions on multipartite systems can be decomposed into a sum of relative entropies of suitably chosen conditional distributions on the individual systems. Here, we prove a chain rule inequality for the quantum relative entropy. The new chain rule allows us to solve an open problem in the context of asymptotic quantum channel discrimination: surprisingly, adaptive protocols cannot improve the error rate for asymmetric channel discrimination compared to nonadaptive strategies.

The endoplasmic reticulum (ER) is an extensive organelle in neurons with important roles at synapses including the regulation of cytosolic Ca 2+ , neurotransmission, lipid metabolism, and membrane trafficking. Despite intriguing evidence for these crucial functions, how the presynaptic ER influences synaptic physiology remains enigmatic. To gain insight into this question, we have generated and characterized mutations in the single extended synaptotagmin ( Esyt ) ortholog in Drosophila melanogaster Esyts are evolutionarily conserved ER proteins with Ca 2+ -sensing domains that have recently been shown to orchestrate membrane tethering and lipid exchange between the ER and plasma membrane. We first demonstrate that Esyt localizes to presynaptic ER structures at the neuromuscular junction. Next, we show that synaptic growth, structure, and homeostatic plasticity are surprisingly unperturbed at synapses lacking Esyt expression. However, neurotransmission is reduced in Esyt mutants, consistent with a presynaptic role in promoting neurotransmitter release. Finally, neuronal overexpression of Esyt enhances synaptic growth and the sustainment of the vesicle pool during intense activity, suggesting that increased Esyt levels may modulate the membrane trafficking and/or resting Ca 2+ pathways that control synapse extension. Thus, we identify Esyt as a presynaptic ER protein that can promote neurotransmission and synaptic growth, revealing the first in vivo neuronal functions of this conserved gene family., (Copyright © 2017 by the Genetics Society of America.)