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The CIF NOLA “river market” represents an important but opaque forward market that serves Gulf exporters and elevators. CIF NOLA bids function similarly to traditional forward contracts; however, like a futures market, firms can offset their forward contractual obligations by offsetting positions in a liquid off-exchange paper market. Analysis shows grain sellers pay a risk premium for fall harvest delivery contracts. However, outside of fall harvest, contract liquidity, coupled with a good institutional balance of long and short market participants, mostly removes the pricing bias commonly found in farmer forward contracting in corn and soybeans.
Lateral memristors consisting of planar Ag electrodes (with sub-micrometer separation) supported on thin films of amorphous zinc-tin-oxide have been characterized. After an initial filament-forming process, each device exhibited volatile, resistive switching. In the low resistance state, the transport mechanism and conductance depended on prior activity and on the imposed current limit, mimicking biologic synaptic plasticity. Microscopic observations performed on each device revealed nanoscale filaments between the electrodes. These filaments were subject to Rayleigh instability and exhibited relaxation times determined by their effective radii. The relaxation times and on:off resistance ratios suggest suitability for threshold switching selector devices.
Maternal obesity is associated with an increased risk for adverse perinatal outcomes. Obesity is also associated with a chronic inflammatory state and metabolic derangements that affect the newborn. The additional use of cardiopulmonary bypass during the neonatal period could impact the systemic inflammatory response in the immediate postoperative period that manifests as cardiac depression and multi-organ dysfunction. This study aimed to determine the association of maternal obesity and excessive weight gain during pregnancy with the immediate postoperative morbidity of neonatal patients undergoing cardiopulmonary bypass.
A retrospective review of neonates who underwent cardiopulmonary bypass within the first 30 days of life at our institution between 2011 and 2013 was conducted. Postoperative variables investigated included the duration of length of mechanical ventilation, length of stay in the ICU, peak vasoactive inotrope scores, and peak lactate level. Maternal obesity was defined as 1st trimester body mass index ⩾30 kg/m2. Excessive weight gain was defined as ⩾12 kg gained during pregnancy. In order to determine the association between maternal obesity or excessive weight gain and postoperative variables, we used multiple linear regression, adjusting for birth weight and risk adjustment for congenital heart surgery score.
Records from 58 mother–baby dyads were examined. After controlling for birth weight and risk adjustment for congenital heart surgery score, there were no significant associations between maternal obesity and excessive weight gain during pregnancy versus all postoperative outcomes measured.
Despite the known negative impact of maternal obesity on perinatal outcomes, we were unable to find associations between maternal obesity and excessive weight gain during pregnancy versus postoperative outcomes.
With the aim to overcome the problems of climatic changes and rising ocean levels, one option is to produce large-scale sustainable energy by nuclear fusion of hydrogen and other very light nuclei similar to the energy source of the sun. Sixty years of worldwide research for the ignition of the heavy hydrogen isotopes deuterium (D) and tritium (T) have come close to a breakthrough for ignition. The problem with the DT fusion is that generated neutrons are producing radioactive waste. One exception as the ideal clean fusion process – without neutron production – is the fusion of hydrogen (H) with the boron isotope 11B11 (B11). In this paper, we have mapped out our research based on recent experiments and simulations for a new energy source. We suggest how HB11 fusion for a reactor can be used instead of the DT option. We have mapped out our HB11 fusion in the following way: (i) The acceleration of a plasma block with a laser beam with the power and time duration of the order of 10 petawatts and one picosecond accordingly. (ii) A plasma confinement by a magnetic field of the order of a few kiloteslas created by a second laser beam with a pulse duration of a few nanoseconds (ns). (iii) The highly increased fusion of HB11 relative to present DT fusion is possible due to the alphas avalanche created in this process. (iv) The conversion of the output charged alpha particles directly to electricity. (v) To prove the above ideas, our simulations show for example that 14 milligram HB11 can produce 300 kWh energy if all achieved results are combined for the design of an absolutely clean power reactor producing low-cost energy.
Evolutionary game theory made its way into the social sciences through a curiously circuitous path. Its origin lay in the realization that the mathematical theory of games developed by von Neumann and Morgenstern (1944) could be used to analyze problems of population biology. Because the fitness of an organism (or a trait) in a population often depends on the relative frequency of other organisms (or traits) present, natural selection can take on a strategic character even when none of the organisms are “rational” in any standard sense.
Although modern evolutionary game theory is typically considered to have begun in the work of Maynard Smith and Price (1973), important precursors exist in the work of R. A. Fisher as early as 1930. In The Genetical Theory of Natural Selection, Fisher sought to explain the approximate equality of the sex ratio in mammals using arguments which can be readily understood in game-theoretic terms. The watershed moment for evolutionary game theory, though, was the publication of Maynard Smith's seminal work Evolution and the Theory of Games in 1982. In that text, Maynard Smith drew together a number of results, both from his own work and that of a number of mathematical biologists, presenting them in a clear, coherent format with minimal mathematical prerequisites.
Over time, economists and other social scientists became interested in evolutionary game theory for a variety of reasons, some stemming from long-standing issues in the traditional theory of games. Of these, perhaps the two most important were as follows: first, as von Neumann and Morgenstern clearly recognized, their theory lacked any underlying dynamics. Early on in Theory of Games and Economic Behaviour, they wrote:
We repeat most emphatically that our theory is thoroughly static. A dynamic theory would unquestionably be more complete and therefore preferable. But there is ample evidence from other branches of science that it is futile to try to build one as long as the static side is not thoroughly understood. (§4.8.2)
Second, the traditional solution concept – that of a Nash equilibrium (which shall be defined below) – suffered from the problem that it was not necessarily unique: games could, and frequently did, have multiple solutions, each of which had some claim to be the “rational” solution.
The effect that cosmic rays and the Alfvén waves generated by them have on the structure of the plasma distribution perpendicular to the galactic disc in a hydrostatic model is examined. It is shown that the plasma distribution exhibits two length scales, essentially because the cosmic rays and Alfvén waves lift the gas up and stretch it out beyond the galactic plane. The predicted gas density far from the galactic plane indicates that models involving hydrostatic equilibrium should be replaced by those allowing for a galactic wind.
In the sequel we will be discussing that - apart from all other halo flows - it is highly probable that our Galaxy has a systematic mass loss; most other galaxies should behave in a similar way. This mass loss should occur in the form of a supersonic galactic wind provided the intergalactic pressure is low enough. We will investigate this possibility mainly for our Galaxy. We shall argue  that the energetic particle component of the interstellar medium, the cosmic rays (CRs), is basically responsible for driving a wind for typical gas temperatures below 106 K. Thus for asymptotic wind velocities of the order of the escape velocity, the mass flux is essentially determined by the observable CR energy loss from the Galaxy. Galaxies with very hot gas on the other hand hardly need the CR component and drive a wind almost exclusively through their thermal pressure.
Psychiatric disorders commonly emerge during the first year following traumatic brain injury (TBI). However, it is not clear whether these disorders soon remit or persist for long periods post-injury. This study aimed to examine, prospectively: (1) the frequency, (2) patterns of co-morbidity, (3) trajectory, and (4) risk factors for psychiatric disorders during the first 5 years following TBI.
Participants were 161 individuals (78.3% male) with moderate (31.2%) or severe (68.8%) TBI. Psychiatric disorders were diagnosed using the Structured Clinical Interview for DSM-IV, administered soon after injury and 3, 6 and 12 months, and 2, 3, 4 and 5 years post-injury. Disorder frequencies and generalized estimating equations were used to identify temporal relationships and risk factors.
In the first 5 years post-injury, 75.2% received a psychiatric diagnosis, commonly emerging within the first year (77.7%). Anxiety, mood and substance-use disorders were the most common diagnostic classes, often presenting co-morbidly. Many (56.5%) experienced a novel diagnostic class not present prior to injury. Disorder frequency ranged between 61.8 and 35.6% over time, decreasing by 27% [odds ratio (OR) 0.73, 95% confidence interval (CI) 0.65–0.83] with each year post-injury. Anxiety disorders declined significantly over time (OR 0.73, 95% CI 0.63–0.84), whilst mood and substance-use disorder rates remained stable. The strongest predictors of post-injury disorder were pre-injury disorder (OR 2.44, 95% CI 1.41–4.25) and accident-related limb injury (OR 1.78, 95% CI 1.03–3.07).
Findings suggest the first year post-injury is a critical period for the emergence of psychiatric disorders. Disorder frequency declines thereafter, with anxiety disorders showing greater resolution than mood and substance-use disorders.
A recent paper by Webb et al. (J. Plasma Phys., vol. 80, 2014, pp. 707–743) on multi-symplectic magnetohydrodynamics (MHD) using Clebsch variables in an Eulerian action principle with constraints is further extended. We relate a class of symplecticity conservation laws to a vorticity conservation law, and provide a corrected form of the Cartan–Poincaré differential form formulation of the system. We also correct some typographical errors (omissions) in Webb et al. (J. Plasma Phys., vol. 80, 2014, pp. 707–743). We show that the vorticity–symplecticity conservation law, that arises as a compatibility condition on the system, expressed in terms of the Clebsch variables is equivalent to taking the curl of the conservation form of the MHD momentum equation. We use the Cartan–Poincaré form to obtain a class of differential forms that represent the system using Cartan’s geometric theory of partial differential equations
The mechanism behind the beneficial effects of enteral nutrition (EN) for patients with acute pancreatitis (AP) is largely unknown. Adipokines, as mediators of metabolism and inflammation, may be a possible mechanism. The study aimed to investigate the effect of EN on adipokines early in the course of AP. Patients with AP were randomised to EN or nil-by-mouth (NBM). Blood samples were taken on the first 4 d of admission and adipokine concentrations for adiponectin, leptin, omentin, resistin and visfatin were determined by ELISA assays. A linear mixed model analysis was run to determine differences in adipokine concentrations between the two study groups. A total of thirty-two patients were included in the study. Omentin concentrations were significantly higher in patients who received EN compared with NBM across the first 4 d of admission (mean difference: 11·6 (95 % CI 1·0, 22·3) ng/ml; P = 0·033). Leptin concentrations were significantly higher in patients who received EN compared with NBM after adjusting for age, sex and BMI (mean difference: 2·3 (95 % CI 0·1, 4·5) ng/ml; P = 0·037). No significant difference in adiponectin, resistin or visfatin concentrations were observed between the two study groups. EN significantly increases omentin and leptin concentrations in AP. Future research should be directed towards understanding whether these adipokines are responsible for the therapeutic benefits of EN.
Clostridium difficile infection (CDI) has been extensively described in healthcare settings; however, risk factors associated with community-acquired (CA) CDI remain uncertain. This study aimed to synthesize the current evidence for an association between commonly prescribed medications and comorbidities with CA-CDI.
A systematic search was conducted in 5 electronic databases for epidemiologic studies that examined the association between the presence of comorbidities and exposure to medications with the risk of CA-CDI. Pooled odds ratios were estimated using 3 meta-analytic methods. Subgroup analyses by location of studies and by life stages were conducted.
Twelve publications (n=56,776 patients) met inclusion criteria. Antimicrobial (odds ratio, 6.18; 95% CI, 3.80–10.04) and corticosteroid (1.81; 1.15–2.84) exposure were associated with increased risk of CA-CDI. Among the comorbidities, inflammatory bowel disease (odds ratio, 3.72; 95% CI, 1.52–9.12), renal failure (2.64; 1.23–5.68), hematologic cancer (1.75; 1.02–5.68), and diabetes mellitus (1.15; 1.05–1.27) were associated with CA-CDI. By location, antimicrobial exposure was associated with a higher risk of CA-CDI in the United States, whereas proton-pump inhibitor exposure was associated with a higher risk in Europe. By life stages, the risk of CA-CDI associated with antimicrobial exposure greatly increased in adults older than 65 years.
Antimicrobial exposure was the strongest risk factor associated with CA-CDI. Further studies are required to investigate the risk of CA-CDI associated with medications commonly prescribed in the community. Patients with diarrhea who have inflammatory bowel disease, renal failure, hematologic cancer, or diabetes are appropriate populations for interventional studies of screening.
Data were extracted from the case records of UK patients admitted with laboratory-confirmed influenza A(H1N1)pdm09. White and non-White patients were characterized by age, sex, socioeconomic status, pandemic wave and indicators of pre-morbid health status. Logistic regression examined differences by ethnicity in patient characteristics, care pathway and clinical outcomes; multivariable models controlled for potential confounders. Whites (n = 630) and non-Whites (n = 510) differed by age, socioeconomic status, pandemic wave of admission, pregnancy, recorded obesity, previous and current smoking, and presence of chronic obstructive pulmonary disease. After adjustment for a priori confounders non-Whites were less likely to have received pre-admission antibiotics [adjusted odds ratio (aOR) 0·43, 95% confidence interval (CI) 0·28–0·68, P < 0·001) but more likely to receive antiviral drugs as in-patients (aOR 1·53, 95% CI 1·08–2·18, P = 0·018). However, there were no significant differences by ethnicity in delayed admission, severity at presentation for admission, or likelihood of severe outcome.
A multi-symplectic formulation of ideal magnetohydrodynamics (MHD) is developed based on the Clebsch variable variational principle in which the Lagrangian consists of the kinetic minus the potential energy of the MHD fluid modified by constraints using Lagrange multipliers that ensure mass conservation, entropy advection with the flow, the Lin constraint, and Faraday's equation (i.e. the magnetic flux is Lie dragged with the flow). The analysis is also carried out using the magnetic vector potential Ã where α=Ã⋅dx is Lie dragged with the flow, and B=∇×Ã. The multi-symplectic conservation laws give rise to the Eulerian momentum and energy conservation laws. The symplecticity or structural conservation laws for the multi-symplectic system corresponds to the conservation of phase space. It corresponds to taking derivatives of the momentum and energy conservation laws and combining them to produce n(n−1)/2 extra conservation laws, where n is the number of independent variables. Noether's theorem for the multi-symplectic MHD system is derived, including the case of non-Cartesian space coordinates, where the metric plays a role in the equations.
Longitudinal studies reporting the association between cannabis use and developing depression provide mixed results. The objective of this study was to establish the extent to which different patterns of use of cannabis are associated with the development of depression using meta-analysis of longitudinal studies.
Peer-reviewed publications reporting the risk of developing depression in cannabis users were located using searches of EMBASE, Medline, PsychINFO and ISI Web of Science. Only longitudinal studies that controlled for depression at baseline were included. Data on several study characteristics, including measures of cannabis use, measures of depression and control variables, were extracted. Odds ratios (ORs) were extracted by age and length of follow-up.
After screening for 4764 articles, 57 articles were selected for full-text review, of which 14 were included in the quantitative analysis (total number of subjects = 76058). The OR for cannabis users developing depression compared with controls was 1.17 [95% confidence interval (CI) 1.05–1.30]. The OR for heavy cannabis users developing depression was 1.62 (95% CI 1.21–2.16), compared with non-users or light users. Meta-regression revealed no significant differences in effect based on age of subjects and marginal difference in effect based on length of follow-up in the individual studies. There was large heterogeneity in the number and type of control variables in the different studies.
Cannabis use, and particularly heavy cannabis use, may be associated with an increased risk for developing depressive disorders. There is need for further longitudinal exploration of the association between cannabis use and developing depression, particularly taking into account cumulative exposure to cannabis and potentially significant confounding factors.
Small scale explosively driven fragmentation experiments have been performed on Aluminum (Al)-Tungsten (W) granular composite rings processed using cold isostatic compression of Al and W powders with a particle size of 4-30 microns. Fragments collected from the experiments had a maximum size of the order of a few hundred micrometers. This is a dramatic reduction in the fragment size when compared to the 1-10 mm typical for a homogeneous material such as solid aluminum under similar loading conditions. Numerical simulations of the experiment were performed to elucidate the mechanisms of fragmentation that were responsible for this shift in fragmentation size scales. Simulations were performed with a significantly stronger explosive driver to examine how the mechanisms of fragmentation change when the detonation pressure increases.