Ancilla-assisted sequential approximation of nonlocal unitary operations

We consider the recently proposed "no-go" theorem of Lamata et al [Phys. Rev. Lett. 101, 180506 (2008)] on the impossibility of sequential implementation of global unitary operations with the aid of an itinerant ancillary system and view the claim within the language of Kraus representation. By virtue of an extremely useful tool for analyzing entanglement properties of quantum operations, namely, operator-Schmidt decomposition, we provide alternative proof to the "no-go" theorem and also study the role of initial correlations between the qubits and ancilla in sequential preparation of unitary entanglers. Despite the negative response from the "no-go" theorem, we demonstrate explicitly how the matrix-product operator(MPO) formalism provides a flexible structure to develop protocols for sequential implementation of such entanglers with an optimal fidelity. The proposed numerical technique, that we call variational matrix-product operator (VMPO), offers a computationally efficient tool for characterizing the "globalness" and entangling capabilities of nonlocal unitary operations.Comment: Slightly improved version as published in Phys. Rev.

Accounting for Underreporting in Mathematical Modeling of Transmission and Control of COVID-19 in Iran

Iran has been the country most affected by the outbreak of SARS-CoV-2 in the Middle East. With a relatively high case fatality ratio and limited testing capacity, the number of confirmed cases reported is suspected to suffer from significant underreporting. Therefore, understanding the transmission dynamics of COVID-19 and assessing the effectiveness of the interventions that have taken place in Iran while accounting for the uncertain level of underreporting is of critical importance. In this paper, we developed a compartmental transmission model to estimate the time-dependent effective reproduction number since the beginning of the outbreak in Iran. We associate the variations in the effective reproduction number with a timeline of interventions and national events. The estimation method accounts for the underreporting due to low case ascertainment. Our estimates of the effective reproduction number ranged from 0.66 to 1.73 between February and April 2020, with a median of 1.16. We estimate a reduction in the effective reproduction number during this period, from 1.73 (95% CI 1.60–1.87) on 1 March 2020 to 0.69 (95% CI 0.68–0.70) on 15 April 2020, due to various non-pharmaceutical interventions. The series of non-pharmaceutical interventions and the public compliance that took place in Iran are found to be effective in slowing down the speed of the spread of COVID-19. However, we argue that if the impact of underreporting is overlooked, the estimated transmission and control dynamics could mislead public health decisions, policy makers, and the general public

Accounting for Underreporting in Mathematical Modeling of Transmission and Control of COVID-19 in Iran

Iran has been the country most affected by the outbreak of SARS-CoV-2 in the Middle East. With a relatively high case fatality ratio and limited testing capacity, the number of confirmed cases reported is suspected to suffer from significant underreporting. Therefore, understanding the transmission dynamics of COVID-19 and assessing the effectiveness of the interventions that have taken place in Iran while accounting for the uncertain level of underreporting is of critical importance. In this paper, we developed a compartmental transmission model to estimate the time-dependent effective reproduction number since the beginning of the outbreak in Iran. We associate the variations in the effective reproduction number with a timeline of interventions and national events. The estimation method accounts for the underreporting due to low case ascertainment. Our estimates of the effective reproduction number ranged from 0.66 to 1.73 between February and April 2020, with a median of 1.16. We estimate a reduction in the effective reproduction number during this period, from 1.73 (95% CI 1.60–1.87) on 1 March 2020 to 0.69 (95% CI 0.68–0.70) on 15 April 2020, due to various non-pharmaceutical interventions. The series of non-pharmaceutical interventions and the public compliance that took place in Iran are found to be effective in slowing down the speed of the spread of COVID-19. However, we argue that if the impact of underreporting is overlooked, the estimated transmission and control dynamics could mislead public health decisions, policy makers, and the general public

3-Hydroxyisobutyryl-CoA hydrolase deficiency in an Iranian child with novel HIBCH compound heterozygous mutations

We report a patient presenting with developmental delay, Leigh-like abnormalities on MRI and elevated 3-hydroxyisovaleric acid levels. Upon whole-exome sequencing, he was diagnosed with 3-hydroxyisobutyryl-CoA hydrolase (HIBCH) deficiency, and hence subjected to specific dietary treatment. HIBCH deficiency should be considered in the differential diagnosis of Leigh-like disease and/or organic aciduria. © 2019 The Authors. Clinical Case Reports published by John Wiley & Sons Ltd

Reasons People Living with HIV Might Prefer Oral Daily Antiretroviral Therapy, Long-Acting Formulations or Future HIV Remission Options

A growing body of research is beginning to elucidate reasons people living with HIV (PLWHIV) might prefer oral daily antiretroviral treatment (ART) compared with emerging long-acting ART (LA-ART) or HIV remission strategies under investigation. Our objective is to provide qualitative insights into the reasons why PLWHIV might prefer one of these HIV control therapies over others. From May to August 2018, we implemented a semistructured cross-sectional survey of PLWHIV in the United States to better understand patient preferences around various HIV treatment and remission options. Using free text, respondents were asked to explain why they preferred one HIV control option over the other two. We analyzed responses to the open-ended survey questions on reasons for preferring oral daily ART versus LA-ART versus HIV remission strategies using conventional content analysis. The results showed that PLWHIV preferred oral daily ART because of its familiarity and known safety and efficacy profile, whereas those who preferred LA-ART would value the convenience it offers. Finally, HIV remission strategies would be preferred to avoid taking ART altogether. The qualitative results provide insights into reasons why PLWHIV in the United States might prefer oral daily ART versus novel therapies. More importantly, they provide information to better align HIV virological control strategies with end-user perspectives. To make informed choices around evolving HIV therapeutics, PLWHIV and HIV care providers would benefit from decision tools to better assess options and trade-offs. More research is needed on how best to effectively support PLWHIV and HIV care providers in shared decision-making

Availability and Half-life of Web References Cited in Information Research Journal: A Citation Study

This article examines availability and half-life of URLs cited in articles published by Information Research journal. To do this, at first, we extracted all issues of Information Research from April 1995 to March 2008 and calculated number of all citations whether printed citations or Web ones. Afterwards, we checked availability of individual cited URLs. When we could not access directly URL inserted in any article by author(s), we tried to visit referred website. If this attempt seemed to be inadequate, search engine "Google" was employed to access the missing reference(s). Research findings indicated that 66% of articles have Web citations and rate of articles containing URL has increased from 17% in 1995 to 89% in 2008. Domains .net and .org have more stability and persistence compared to domains .edu, .gov, .uk and .com. Also, of 1761 cited URLs, 73% were accessible, and 27% were inaccessible. It is notable that using Google and searching missing URLs, accessible URLs increased from 73% to 86%. Finally, it was recommended that the best solution to prevent decay or disappearance of Web citations and diminish URLs decay is to make use of WebCite®-enhanced reference

Three Dimensional Ising Model, Percolation Theory and Conformal Invariance

The fractal structure and scaling properties of a 2d slice of the 3d Ising model is studied using Monte Carlo techniques. The percolation transition of geometric spin (GS) clusters is found to occur at the Curie point, reflecting the critical behavior of the 3d model. The fractal dimension and the winding angle statistics of the perimeter and external perimeter of the geometric spin clusters at the critical point suggest that, if conformally invariant in the scaling limit, they can be described by the theory of Schramm-Loewner evolution (SLE_\kappa) with diffusivity of \kappa=5 and 16/5, respectively, putting them in the same universality class as the interfaces in 2d tricritical Ising model. It is also found that the Fortuin-Kasteleyn (FK) clusters associated with the cross sections undergo a nontrivial percolation transition, in the same universality class as the ordinary 2d critical percolation.Comment: 5 pages, 5 figures, accepted for publication in EuroPhysics Letters (EPL

Cerebral mGluR5 availability contributes to elevated sleep need and behavioral adjustment after sleep deprivation.

Increased sleep time and intensity quantified as low-frequency brain electrical activity after sleep loss demonstrate that sleep need is homeostatically regulated, yet the underlying molecular mechanisms remain elusive. We here demonstrate that metabotropic glutamate receptors of subtype 5 (mGluR5) contribute to the molecular machinery governing sleep-wake homeostasis. Using positron emission tomography, magnetic resonance spectroscopy, and electroencephalography in humans, we find that increased mGluR5 availability after sleep loss tightly correlates with behavioral and electroencephalographic biomarkers of elevated sleep need. These changes are associated with altered cortical myo-inositol and glycine levels, suggesting sleep loss-induced modifications downstream of mGluR5 signaling. Knock-out mice without functional mGluR5 exhibit severe dysregulation of sleep-wake homeostasis, including lack of recovery sleep and impaired behavioral adjustment to a novel task after sleep deprivation. The data suggest that mGluR5 contribute to the brain's coping mechanisms with sleep deprivation and point to a novel target to improve disturbed wakefulness and sleep

The effect of a hydrolyzed collagen-based supplement on wound healing in patients with burn: A randomized double-blind pilot clinical trial

Introduction: Burn is among the most severe forms of critical illness, associated with extensive and prolonged physical, metabolic and mental disorders. The aim of this study was to assess the effect of an oral, low-cost, and accessible collagen-based supplement on wound healing in patients with burn. Methods: In this randomized double-blind controlled pilot clinical trial, 31 men, 18�60 years, with 20�30 total body surface area burn were studied. Patients were randomly assigned to receive either a collagen-based supplement (1000 kcal) or an isocaloric placebo, for 4 weeks. Serum pre-albumin, rate of wound healing, length of hospital stay, and anthropometries were assessed at baseline, and the end of week 2 and 4. Results: Serum pre-albumin was significantly higher at week 2 (29.7 ± 13.6 vs. 17.8 ± 7.5 mg/dL, P = 0.006) and week 4 (35.1 ± 7.6 vs. 28.3 ± 8.2 mg/dL, P = 0.023) in collagen than control group. Changes in pre-albumin concentration were also significantly higher in collagen group at week 2 (13.9 ± 9.8 vs. �1.9 ± 10.3 mg/dL, P < 0.001) and week 4 (19.2 ± 7.5 vs. 8.5 ± 10.1 mg/dL, P = 0.002). The Hazard ratio of wound healing was 3.7 times in collagen compared to control group (95 CI: 1.434�9.519, P = 0.007). Hospital stay was clinically, but not statistically, lower in collagen than control group (9.4 ± 4.6 vs. 13.5 ± 7 days, P = 0.063). There were no significant differences in weight, body mass index, dietary energy and protein intakes between the two groups. Conclusion: The findings showed that a hydrolyzed collagen-based supplement could significantly improve wound healing and circulating pre-albumin, and clinically reduce hospital stay in patients with 20�30 burn. © 2019 Elsevier Ltd and ISB

Optimization of visual tasks for detecting visual cortex activity in fMRI studies

The aim of this study was to optimize visual stimuli in various forms of visual tasks for acquiring significant and robust signals. The effects of physical parameters of visual stimuli for detecting visual cortical activity were evaluated by functional magnetic resonance imaging. These parameters were temporal frequency (TF), spatial frequency (SF), the different patterns of activation including: square wave and sine wave grating, and two different states of rest including black and white screen. Functional Magnetic Resonance Imaging (fMRI) was performed by 1.5 Tesla General Electric system in 14 volunteers (9 males and 5 females, range 19-26 years). The activation map was created using the data obtained from the block designed fMRI study. Pixels whose Z value was above a threshold of 2.3, in significant level P=0.05 were considered activated. The average percentage BOLD (blood oxygenation level dependent) signal change for all activated pixels within the occipital lobe, multiplied by the total number of activated pixels within the occipital lobe, was used as a measure for the strength of the fMRI signal at each state of TF& SF. The results demonstrated that the strength of the fMRI signal was maximum in the TF of 8 Hz with low spatial frequency of 0.50 cycle per degree (cpd) and using the black screen in the rest state. However there isn't significant difference between square-wave and sine-wave grating in producing visual activation in cortex. Physical parameters of visual tasks are effective in detecting visual cortical activity, and it is necessary to consider them for taking significant and robust signal. © International Federation for Medical and Biological Engineering 2007