Securing Downlink Massive MIMO-NOMA Networks with Artificial Noise

In this paper, we focus on securing the confidential information of massive multiple-input multiple-output (MIMO) non-orthogonal multiple access (NOMA) networks by exploiting artificial noise (AN). An uplink training scheme is first proposed with minimum mean squared error estimation at the base station. Based on the estimated channel state information, the base station precodes the confidential information and injects the AN. Following this, the ergodic secrecy rate is derived for downlink transmission. An asymptotic secrecy performance analysis is also carried out for a large number of transmit antennas and high transmit power at the base station, respectively, to highlight the effects of key parameters on the secrecy performance of the considered system. Based on the derived ergodic secrecy rate, we propose the joint power allocation of the uplink training phase and downlink transmission phase to maximize the sum secrecy rates of the system. Besides, from the perspective of security, another optimization algorithm is proposed to maximize the energy efficiency. The results show that the combination of massive MIMO technique and AN greatly benefits NOMA networks in term of the secrecy performance. In addition, the effects of the uplink training phase and clustering process on the secrecy performance are revealed. Besides, the proposed optimization algorithms are compared with other baseline algorithms through simulations, and their superiority is validated. Finally, it is shown that the proposed system outperforms the conventional massive MIMO orthogonal multiple access in terms of the secrecy performance

Innovative in silico approaches to address avian flu using grid technology

The recent years have seen the emergence of diseases which have spread very quickly all around the world either through human travels like SARS or animal migration like avian flu. Among the biggest challenges raised by infectious emerging diseases, one is related to the constant mutation of the viruses which turns them into continuously moving targets for drug and vaccine discovery. Another challenge is related to the early detection and surveillance of the diseases as new cases can appear just anywhere due to the globalization of exchanges and the circulation of people and animals around the earth, as recently demonstrated by the avian flu epidemics. For 3 years now, a collaboration of teams in Europe and Asia has been exploring some innovative in silico approaches to better tackle avian flu taking advantage of the very large computing resources available on international grid infrastructures. Grids were used to study the impact of mutations on the effectiveness of existing drugs against H5N1 and to find potentially new leads active on mutated strains. Grids allow also the integration of distributed data in a completely secured way. The paper presents how we are currently exploring how to integrate the existing data sources towards a global surveillance network for molecular epidemiology.Comment: 7 pages, submitted to Infectious Disorders - Drug Target

Postprandial response of plasma insulin, amylin and acylated ghrelin to various test meals in lean and obese cats

The propensity of diets of different composition to promote obesity is a current topic in feline medicine. The effects of three meals with different protein:fat ratios on hormones (insulin, acylated ghrelin and amylin) involved in the control of food intake and glucose metabolism were compared. Five lean (two females and three males, 28·6 (sd 3·4) % body fat mass (BFM), mean body weight (BW) 4590g) and five obese (two females and three males, 37·1 (sd 4·1) % BFM, mean BW 4670g) adult cats were studied. Only BFM differed significantly between obese and lean cats. The cats were fed a high-protein (HP), a high-fat and a high-carbohydrate diet in a randomised cross-over design. Food intake did not differ between cats fed on the different diets, but obese cats consumed significantly more energy, expressed as per kg fat-free mass, than lean cats. After a 6-week adaptation period, a test meal was given and blood samples were collected before and 0, 30, 60 and 100min after the meal. Baseline concentrations of glucose, amylin and acylated ghrelin were higher in obese cats than in lean cats, and obese cats showed the highest postprandial responses of glucose and amylin. The HP diet led to higher postprandial amylin concentrations than the other diets, indicating a possible effect of amino acids on β-cell secretion. Postprandial ghrelin concentrations were unaffected by diet composition. The relationship between insulin, amylin and ghrelin secretion and their relevant roles in food intake and glucose metabolism in cats require further stud

Acute hormonal response to glucose, lipids and arginine infusion in overweight cats

In cats, the incidence of obesity and diabetes is increasing, and little is known about specific aspects of the endocrine control of food intake in this species. Recent data suggest that ghrelin has an important role in the control of insulin secretion and vice versa, but this role has never been demonstrated in cats. Here we aimed to improve our understanding about the relationship between insulin, amylin and ghrelin secretion in response to a nutrient load in overweight cats. After a 16h fast, weekly, six overweight male cats underwent randomly one of the four testing sessions: saline, glucose, arginine and TAG. All solutions were isoenergetic and isovolumic, and were injected intravenously as a bolus. Glucose, insulin, acylated ghrelin (AG), amylin and prolactin were assayed in plasma before and 10, 20, 40, 60, 80 and 100min after the nutrient load. A linear mixed-effects model was used to assess the effect of bolus and time on the parameters. A parenteral bolus of glucose or arginine increased insulin and ghrelin concentrations in cats. Except for with the TAG bolus, no suppression of ghrelin was observed. The absence of AG suppression after the intravenous load of arginine and glucose may suggest: (1) that some nutrients do not promote satiation in overweight cats; or that (2) AG may be involved in non-homeostatic consumption mechanisms. However, the role of ghrelin in food reward remains to be assessed in cat

Diet quality in childhood: the Generation R Study

Purpose: We aimed to evaluate diet quality of 8-year-old children in the Netherlands, to identify sociodemographic and lifestyle correlates of child diet quality, and to examine tracking of diet quality from ea

Molecular mechanism of Gαi activation by non-GPCR proteins with a Gα-Binding and Activating motif

Heterotrimeric G proteins are quintessential signalling switches activated by nucleotide exchange on Gα. Although activation is predominantly carried out by G-protein-coupled receptors (GPCRs), non-receptor guanine-nucleotide exchange factors (GEFs) have emerged as critical signalling molecules and therapeutic targets. Here we characterize the molecular mechanism of G-protein activation by a family of non-receptor GEFs containing a Gα-binding and -activating (GBA) motif. We combine NMR spectroscopy, computational modelling and biochemistry to map changes in Gα caused by binding of GBA proteins with residue-level resolution. We find that the GBA motif binds to the SwitchII/α3 cleft of Gα and induces changes in the G-1/P-loop and G-2 boxes (involved in phosphate binding), but not in the G-4/G-5 boxes (guanine binding). Our findings reveal that G-protein-binding and activation mechanisms are fundamentally different between GBA proteins and GPCRs, and that GEF-mediated perturbation of nucleotide phosphate binding is sufficient for Gα activation

Lymphocyte Homing to Bronchus-associated Lymphoid Tissue (BALT) Is Mediated by L-selectin/PNAd, α4β1 Integrin/VCAM-1, and LFA-1 Adhesion Pathways

Bronchus-associated lymphoid tissue (BALT) participates in airway immune responses. However, little is known about the lymphocyte–endothelial adhesion cascades that recruit lymphocytes from blood into BALT. We show that high endothelial venules (HEVs) in BALT express substantial levels of VCAM-1, in marked contrast to HEVs in other secondary lymphoid tissues. BALT HEVs also express the L-selectin ligand PNAd. Anti–L-selectin, anti-PNAd, and anti–LFA-1 mAbs almost completely block the homing of B and T lymphocytes into BALT, whereas anti–α4 integrin and anti–VCAM-1 mAbs inhibit homing by nearly 40%. α4β7 integrin and MAdCAM-1 are not involved. Importantly, we found that mAbs against α4 integrin and VCAM-1 significantly block the migration of total T cells (80% memory phenotype) but not naive T and B cells to BALT. These results suggest that an adhesion cascade, which includes L-selectin/PNAd, α4β1 integrin/VCAM-1, and LFA-1, targets specific lymphocyte subsets to BALT. This high level of involvement of α4β1 integrin/VCAM-1 is unique among secondary lymphoid tissues, and may help unify lymphocyte migration pathways and immune responses in BALT and other bronchopulmonary tissues

Feasibility of Tomotherapy-Based Image-Guided Radiotherapy to Reduce Aspiration Risk in Patients with Non-Laryngeal and Non-Pharyngeal Head and Neck Cancer

PURPOSE: The study aims to assess the feasibility of Tomotherapy-based image-guided radiotherapy (IGRT) to reduce the aspiration risk in patients with non-laryngeal and non-hypopharyngeal cancer. A retrospective review of 48 patients undergoing radiation for non-laryngeal and non-hypopharyngeal head and neck cancers was conducted. All patients had a modified barium swallow (MBS) prior to treatment, which was repeated one month following radiotherapy. Mean middle and inferior pharyngeal dose was recorded and correlated with the MBS results to determine aspiration risk. RESULTS: Mean pharyngeal dose was 23.2 Gy for the whole group. Two patients (4.2%) developed trace aspiration following radiotherapy which resolved with swallowing therapy. At a median follow-up of 19 months (1-48 months), all patients were able to resume normal oral feeding without aspiration. CONCLUSION AND CLINICAL RELEVANCE: IGRT may reduce the aspiration risk by decreasing the mean pharyngeal dose in the presence of large cervical lymph nodes. Further prospective studies with IGRT should be performed in patients with non-laryngeal and non-hypopharyngeal head and neck cancers to verify this hypothesis

Excited-state OH Mainline Masers in AU Geminorum and NML Cygni

Excited-state OH maser emission has previously been reported in the circumstellar envelopes of only two evolved stars: the Mira star AU Geminorum and the hypergiant NML Cygni. We present Very Large Array (VLA) observations of the 1665, 1667, and excited-state 4750 MHz mainline OH transitions in AU Gem and Expanded Very Large Array (EVLA) observations of the excited-state 6030 and 6035 MHz OH mainline transitions in NML Cyg. We detect masers in both mainline transitions in AU Gem but no excited-state emission in either star. We conclude that the excited-state OH emission in AU Gem is either a transient phenomenon (such as for NML Cyg outlined below), or possibly an artifact in the data, and that the excited state OH emission in NML Cyg was generated by an episode of enhanced shock between the stellar mass-loss and an outflow of the Cyg OB2 association. With these single exceptions, it therefore appears that excited-state OH emission indeed should not be predicted nor observable in evolved stars as part of their normal structure or evolution.Comment: ApJ Letter, accepted, 4 pages, 2 figure

Rapid Identification of Thrombocytopenia-Associated Multiple Organ Failure Using Red Blood Cell Parameters and a Volume/Hemoglobin Concentration Cytogram

Thrombocytopenia-associated multiple organ failure (TAMOF) has a high mortality rate when not treated, and early detection of TAMOF is very important diagnostically and therapeutically. We describe herein our experience of early detection of TAMOF, using an automated hematology analyzer. From 498,390 inpatients, we selected 12 patients suspected of having peripheral schistocytosis, based on the results of red blood cell (RBC) parameters and a volume/hemoglobin concentration (V/HC) cytogram. We promptly evaluated whether the individual patients had clinical manifestations and laboratory findings were consistent with TAMOF. Plasma exchanges were then performed for each patient. All 12 patients had TAMOF. The mean values of RBC parameters were significantly higher in all of the patients than with the reference range, however, 3 patients had % RBC fragments within the reference range. The mean value of ADAMTS-13 activity was slightly lower in patients compared with the reference range. Of the 12 patients, remission was obtained in 9 patients (75%) within 4 to 5 weeks using plasma exchanges. Three patients died. An increased percentage of microcytic hyperchromic cells with anisocytosis and anisochromia indicated the presence of schistocytes, making it an excellent screening marker for TAMOF. Identification of TAMOF with RBC parameters and a V/HC cytogram is a facile and rapid method along with an automated hematology analyzer already in use for routine complete blood cell counting test