A preliminary investigation for accidental load design of a submerged floating tube bridges

Submerged floating tunnels are more and more considered as a suitable solution to cross water channels limiting environmental impact on the visual landscape and ensuring large ship passage while crossing large distances between coasts. The design of this kind of strategical infrastructures must deal not only with live loads and particular loading conditions coming from the floating situation, but needs also to carefully consider accidental actions that concur to the global safety of the infrastructure. The construction of the new E39 highway along the Norwegian coast asks for crossing several fjords and this solution is seriously taken into consideration. For this reason, a comprehensive research program was aimed at the analysis of accidental load design of the infrastructure. This paper aims to present a comprehensive overview of an ad-hoc experimental investigation on the behavior of reinforced concrete (RC) circular slabs (60 cm diameter) under exposure to fire, blast, or a combination of both actions. Additionally, it seeks to draw design-driven conclusions that could be valuable for the design of critical infrastructure in scenarios involving fire and blast. The presented experimental campaign was intended to provide a benchmark for assessing the reliability of the design approaches to be adopted in the design of the global infrastructure. First of all, the concrete mechanical characterization at normal conditions and at high temperatures was performed referring both to uniaxial compression and uniaxial tension. The structural behavior of simply supported RC slabs has also been investigated by considering slabs exposed to a hydrocarbon fire curve at different exposure times and by considering the post-fire application of static or dynamic loading condition. In particular, the fire curve was applied by a gas burner while the dynamic load was reproduced by a shock tube equipment that was used to apply two different blast-like pressure histories

Determination of dipole coupling constants using heteronuclear multiple quantum NMR

The problem of extracting dipole couplings from a system of N spins I = 1/2 and one spin S by NMR techniques is analyzed. The resolution attainable using a variety of single quantum methods is reviewed. The theory of heteronuclear multiple quantum (HMQ) NMR is developed, with particular emphasis being placed on the superior resolution available in HMQ spectra. Several novel pulse sequences are introduced, including a two-step method for the excitation of HMQ coherence. Experiments on partially oriented [1−13C] benzene demonstrate the excitation of the necessary HMQ coherence and illustrate the calculation of relative line intensities. Spectra of high order HMQ coherence under several different effective Hamiltonians achievable by multiple pulse sequences are discussed. A new effective Hamiltonian, scalar heteronuclear recoupled interactions by multiple pulse (SHRIMP), achieved by the simultaneous irradiation of both spin species with the same multiple pulse sequence, is introduced. Experiments are described which allow heteronuclear couplings to be correlated with an S-spin spreading parameter in spectra free of inhomogeneous broadening

Single-center open-label randomized study of anemia management improvement in ESRD patients with secondary hyperparathyroidism

Whether anemia and mineral bone abnormalities (chronic kidney disease\u2013mineral bone disorder [CKD-MBD]) are associated still remains to be elucidated. Both anemia and CKD-MBD have been associated with adverse cardiovascular outcome and poor quality of life. However, recent evidence suggests that use of large doses of erythropoietin-stimulating agents (ESAs) to correct hemoglobin (Hb) may be detrimental in CKD. The Optimal Anemia Treatment in End Stage Renal Disease (ESRD) (Optimal ESRD Treatment) study will assess whether lowering of parathyroid hormone (PTH) is associated with a reduction in ESA consumption. The Optimal ESRD Treatment study is a pilot single-center open-label study with blinded end point (a prospective randomized open blinded end-point [PROBE] design) enrolling 50 patients on maintenance dialysis. Eligible patients with intact PTH (iPTH) 300-540 pg/mL and Hb 10-11.5 g/dL will be randomized 1:1 to strict PTH control (150-300 pg/mL) versus standard care (PTH range 300-540 pg/mL). Available drugs for CKD-MBD and anemia treatment will be managed by the attending physician to maintain the desired levels of PTH (according to study arm allocation) and Hb (10-11.5 g/dL). Echocardiographic data for cardiac structure and function as well as arterial stiffness will be assessed at study inception and completion. The Optimal ESRD Treatment study should shed light on the complicated interplay of anemia and CKD-MBD and on the feasibility of clinical trials in this domain. The study results are expected in the spring of 2017

Sudden Death in End Stage Renal Disease : Comparing Hemodialysis versus Peritoneal Dialysis

Background/Aims: This study aimed to evaluate total and sudden death (SD) in a cohort of dialysis patients, comparing hemodialysis (HD) vs. peritoneal dialysis (PD). Methods: This is a multicenter retrospective cohort study. Results: Deaths were 626 out of 1,823 in HD and 62 of 249 in PD patients. HD patients had a greater number of comorbidities (p < 0.05). PD patients had a lower risk of death than HD patients (p < 0.001); however, the advantage decreased with time (p < 0.001). Mortality predictors were left ventricular ejection fraction (LVEF) \ue2\u89\ua435%, older age, ischemic heart disease, diabetes mellitus, previous stroke, and atrial fibrillation (p < 0.03). SDs were 84:71 in HD and 13 in PD population (12.1 and 22.8% of all causes of death, respectively). A non-significant risk of SD among PD compared to HD patients was detected. SD predictors were older age, ischemic heart disease, and LVEF \ue2\u89\ua435% (p < 0.05). Conclusions: HD patients showed a greater presence of comorbidities and reduced survival compared to PD patients; however, the incidence of SD does not differ in the 2 populations. Video Journal Club "Cappuccino with Claudio Ronco" at http://www.karger.com/?doi=464347

Endophytic fungi decrease available resources for the aphid Rhopalosiphum padi and impair their ability to induce defences against predators

1. The production of winged morphs is a well known mechanism of induced defence in aphids to escape from natural enemies, and is also a reaction to poor resource quality. 2. Host plants of aphids often associate with endophytic fungi that have been shown to reduce the fitness of some species of aphids. 3. It was hypothesised that endophyte infection of host plants that represent a low quality plant resource should increase the aphid’s induced response to a predator because both low plant quality and predator presence represent a stronger cue for wing production than predator presence alone. 4. In a laboratory experiment, bird cherry-oat aphids Rhopalosiphum padi L. were exposed to the factors predator threat and endophyte infection and the effects of these factors on the proportion of winged morphs produced by the aphid colonies was analysed. 5. The presence of endophytic fungi strongly decreased aphid colony sizes. When a predator threat was present, all colonies on endophyte-free grasses produced winged morphs whereas only a few colonies were able to produce winged morphs on endophyteinfected grasses. However, these few colonies produced larger proportions of winged morphs than colonies on endophyte-free grasses. Without a predator threat, no colonies on endophyte-infected grasses produced any winged morphs. 6. These results show that aphids in stressed conditions and with reduced fitness will only invest in inducible defences when predators are present but are unable to produce winged morphs in response to endophyte presence