Quantum optical coherence can survive photon losses: a continuous-variable quantum erasure correcting code

A fundamental requirement for enabling fault-tolerant quantum information processing is an efficient quantum error-correcting code (QECC) that robustly protects the involved fragile quantum states from their environment. Just as classical error-correcting codes are indispensible in today's information technologies, it is believed that QECC will play a similarly crucial role in tomorrow's quantum information systems. Here, we report on the first experimental demonstration of a quantum erasure-correcting code that overcomes the devastating effect of photon losses. Whereas {\it errors} translate, in an information theoretic language, the noise affecting a transmission line, {\it erasures} correspond to the in-line probabilistic loss of photons. Our quantum code protects a four-mode entangled mesoscopic state of light against erasures, and its associated encoding and decoding operations only require linear optics and Gaussian resources. Since in-line attenuation is generally the strongest limitation to quantum communication, much more than noise, such an erasure-correcting code provides a new tool for establishing quantum optical coherence over longer distances. We investigate two approaches for circumventing in-line losses using this code, and demonstrate that both approaches exhibit transmission fidelities beyond what is possible by classical means.Comment: 5 pages, 4 figure

Delineation of Culicoides species by morphology and barcode exemplified by three new species of the subgenus Culicoides (Diptera: Ceratopogonidae) from Scandinavia

BACKGROUND: Culicoides biting midges (Diptera: Ceratopogonidae) cause biting nuisance to livestock and humans and are vectors of a range of pathogens of medical and veterinary importance. Despite their economic significance, the delineation and identification of species where only morphology is considered, as well as the evolutionary relationships between species within this genus remains problematic. In recent years molecular barcoding has assisted substantially in the identification of biting midges in the multiple entomological survey projects which were initiated in many European countries following the bluetongue outbreak in 2006–2009. These studies revealed potentially new species and “species-complexes” with large genetic and morphological variability. Here we use molecular barcoding, together with morphological analysis, to study subgenus Culicoides Latreille from Scandinavia with focus on three potentially new species. METHODS: Biting midges were collected at various sites in Denmark and Sweden. Culicoides specimens were described by variation of a fragment of their cytochrome c oxidase subunit 1 (COI) gene sequence and wing, palp and antennal characters. RESULTS: It is shown that three new species initially separated by DNA barcoding with mitochondrial COI can be distinguished by morphological characters. In this context a key to Scandinavian subgenus Culicoides using wing and maxillary palp characters is presented. The key is including the three new species Culicoides boyi, Culicoides selandicus and Culicoides kalix. CONCLUSION: Three new species of Culicoides biting midges were identified and could be identified by both molecular and morphological differences. Evaluation of differences between and within taxa of biting midges using COI barcode yielded a rough estimate of species delineation; interspecies differences across Culicoides subgenera approaches 20%, whereas intraspecies differences are below 4% and in most cases below 1%. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13071-015-0750-4) contains supplementary material, which is available to authorized users

The Functional DRD3 Ser9Gly Polymorphism (rs6280) Is Pleiotropic, Affecting Reward as Well as Movement

Abnormalities of motivation and behavior in the context of reward are a fundamental component of addiction and mood disorders. Here we test the effect of a functional missense mutation in the dopamine 3 receptor (DRD3) gene (ser9gly, rs6280) on reward-associated dopamine (DA) release in the striatum. Twenty-six healthy controls (HCs) and 10 unmedicated subjects with major depressive disorder (MDD) completed two positron emission tomography (PET) scans with [11C]raclopride using the bolus plus constant infusion method. On one occasion subjects completed a sensorimotor task (control condition) and on another occasion subjects completed a gambling task (reward condition). A linear regression analysis controlling for age, sex, diagnosis, and self-reported anhedonia indicated that during receipt of unpredictable monetary reward the glycine allele was associated with a greater reduction in D2/3 receptor binding (i.e., increased reward-related DA release) in the middle (anterior) caudate (p<0.01) and the ventral striatum (p<0.05). The possible functional effect of the ser9gly polymorphism on DA release is consistent with previous work demonstrating that the glycine allele yields D3 autoreceptors that have a higher affinity for DA and display more robust intracellular signaling. Preclinical evidence indicates that chronic stress and aversive stimulation induce activation of the DA system, raising the possibility that the glycine allele, by virtue of its facilitatory effect on striatal DA release, increases susceptibility to hyperdopaminergic responses that have previously been associated with stress, addiction, and psychosis

Prospective research on musculoskeletal disorders in office workers (PROMO): study protocol

BACKGROUND: This article describes the background and study design of the PROMO study (Prospective Research on Musculoskeletal disorders in Office workers). Few longitudinal studies have been performed to investigate the risk factors responsible for the incidence of hand, arm, shoulder and neck symptoms among office workers, given the observation that a large group of office workers might be at risk worldwide. Therefore, the PROMO study was designed. The main aim is to quantify the contribution of exposure to occupational computer use to the incidence of hand, arm, shoulder and neck symptoms. The results of this study might lead to more effective and/or cost-efficient preventive interventions among office workers. METHODS/DESIGN: A prospective cohort study is conducted, with a follow-up of 24 months. In total, 1821 participants filled out the first questionnaire (response rate of 74%). Data on exposure and outcome is collected using web-based self-reports. Outcome assessment takes place every three months during the follow-up period. Data on computer use are collected at baseline and continuously during follow-up using a software program. DISCUSSION: The advantages of the PROMO study include the long follow-up period, the repeated measurement of both exposure and outcome, and the objective measurement of the duration of computer use. In the PROMO study, hypotheses stemming from lab-based and field-based research will be investigated

Elite Suppressors Harbor Low Levels of Integrated HIV DNA and High Levels of 2-LTR Circular HIV DNA Compared to HIV+ Patients On and Off HAART

Elite suppressors (ES) are a rare population of HIV-infected individuals that are capable of naturally controlling the infection without the use of highly active anti-retroviral therapy (HAART). Patients on HAART often achieve viral control to similar (undetectable) levels. Accurate and sensitive methods to measure viral burden are needed to elucidate important differences between these two patient populations in order to better understand their mechanisms of control. Viral burden quantification in ES patients has been limited to measurements of total DNA in PBMC, and estimates of Infectious Units per Million cells (IUPM). There appears to be no significant difference in the level of total HIV DNA between cells from ES patients and patients on HAART. However, recovering infectious virus from ES patient samples is much more difficult, suggesting their reservoir size should be much smaller than that in patients on HAART. Here we find that there is a significant difference in the level of integrated HIV DNA in ES patients compared to patients on HAART, providing an explanation for the previous results. When comparing the level of total to integrated HIV DNA in these samples we find ES patients have large excesses of unintegrated HIV DNA. To determine the composition of unintegrated HIV DNA in these samples, we measured circular 2-LTR HIV DNA forms and found ES patients frequently have high levels of 2-LTR circles in PBMC. We further show that these high levels of 2-LTR circles are not the result of inefficient integration in ES cells, since HIV integrates with similar efficiency in ES and normal donor cells. Our findings suggest that measuring integration provides a better surrogate of viral burden than total HIV DNA in ES patients. Moreover, they add significantly to our understanding of the mechanisms that allow viral control and reservoir maintenance in this unique patient population

Antidromic vasodilatation and the migraine mechanism

Despite the fact that an unprecedented series of new discoveries in neurochemistry, neuroimaging, genetics and clinical pharmacology accumulated over the last 20 years has significantly increased our current knowledge, the underlying mechanism of the migraine headache remains elusive. The present review article addresses, from early evidence that emerged at the end of the nineteenth century, the role of ‘antidromic vasodilatation’ as part of the more general phenomenon, currently defined as neurogenic inflammation, in the unique type of pain reported by patients suffering from migraine headaches. The present paper describes distinctive orthodromic and antidromic properties of a subset of somatosensory neurons, the vascular- and neurobiology of peptides contained in these neurons, and the clinical–pharmacological data obtained in recent investigations using provocation tests in experimental animals and human beings. Altogether, previous and recent data underscore that antidromic vasodilatation, originating from the activation of peptidergic somatosensory neurons, cannot yet be discarded as a major contributing mechanism of the throbbing head pain and hyperalgesia of migraine

Bryostatin Modulates Latent HIV-1 Infection via PKC and AMPK Signaling but Inhibits Acute Infection in a Receptor Independent Manner

HIV's ability to establish long-lived latent infection is mainly due to transcriptional silencing in resting memory T lymphocytes and other non dividing cells including monocytes. Despite an undetectable viral load in patients treated with potent antiretrovirals, current therapy is unable to purge the virus from these latent reservoirs. In order to broaden the inhibitory range and effectiveness of current antiretrovirals, the potential of bryostatin was investigated as an HIV inhibitor and latent activator. Bryostatin revealed antiviral activity against R5- and X4-tropic viruses in receptor independent and partly via transient decrease in CD4/CXCR4 expression. Further, bryostatin at low nanomolar concentrations robustly reactivated latent viral infection in monocytic and lymphocytic cells via activation of Protein Kinase C (PKC) -α and -δ, because PKC inhibitors rottlerin and GF109203X abrogated the bryostatin effect. Bryostatin specifically modulated novel PKC (nPKC) involving stress induced AMP Kinase (AMPK) inasmuch as an inhibitor of AMPK, compound C partially ablated the viral reactivation effect. Above all, bryostatin was non-toxic in vitro and was unable to provoke T-cell activation. The dual role of bryostatin on HIV life cycle may be a beneficial adjunct to the treatment of HIV especially by purging latent virus from different cellular reservoirs such as brain and lymphoid organs

Whole Genome Expression Array Profiling Highlights Differences in Mucosal Defense Genes in Barrett's Esophagus and Esophageal Adenocarcinoma

Esophageal adenocarcinoma (EAC) has become a major concern in Western countries due to rapid rises in incidence coupled with very poor survival rates. One of the key risk factors for the development of this cancer is the presence of Barrett's esophagus (BE), which is believed to form in response to repeated gastro-esophageal reflux. In this study we performed comparative, genome-wide expression profiling (using Illumina whole-genome Beadarrays) on total RNA extracted from esophageal biopsy tissues from individuals with EAC, BE (in the absence of EAC) and those with normal squamous epithelium. We combined these data with publically accessible raw data from three similar studies to investigate key gene and ontology differences between these three tissue states. The results support the deduction that BE is a tissue with enhanced glycoprotein synthesis machinery (DPP4, ATP2A3, AGR2) designed to provide strong mucosal defenses aimed at resisting gastro-esophageal reflux. EAC exhibits the enhanced extracellular matrix remodeling (collagens, IGFBP7, PLAU) effects expected in an aggressive form of cancer, as well as evidence of reduced expression of genes associated with mucosal (MUC6, CA2, TFF1) and xenobiotic (AKR1C2, AKR1B10) defenses. When our results are compared to previous whole-genome expression profiling studies keratin, mucin, annexin and trefoil factor gene groups are the most frequently represented differentially expressed gene families. Eleven genes identified here are also represented in at least 3 other profiling studies. We used these genes to discriminate between squamous epithelium, BE and EAC within the two largest cohorts using a support vector machine leave one out cross validation (LOOCV) analysis. While this method was satisfactory for discriminating squamous epithelium and BE, it demonstrates the need for more detailed investigations into profiling changes between BE and EAC