Multiresolution spatiotemporal mechanical model of the heart as a prior to constrain the solution for 4D models of the heart.

In several nuclear cardiac imaging applications (SPECT and PET), images are formed by reconstructing tomographic data using an iterative reconstruction algorithm with corrections for physical factors involved in the imaging detection process and with corrections for cardiac and respiratory motion. The physical factors are modeled as coefficients in the matrix of a system of linear equations and include attenuation, scatter, and spatially varying geometric response. The solution to the tomographic problem involves solving the inverse of this system matrix. This requires the design of an iterative reconstruction algorithm with a statistical model that best fits the data acquisition. The most appropriate model is based on a Poisson distribution. Using Bayes Theorem, an iterative reconstruction algorithm is designed to determine the maximum a posteriori estimate of the reconstructed image with constraints that maximizes the Bayesian likelihood function for the Poisson statistical model. The a priori distribution is formulated as the joint entropy (JE) to measure the similarity between the gated cardiac PET image and the cardiac MRI cine image modeled as a FE mechanical model. The developed algorithm shows the potential of using a FE mechanical model of the heart derived from a cardiac MRI cine scan to constrain solutions of gated cardiac PET images

Sub-Fourier characteristics of a δ\delta-kicked rotor resonance

We experimentally investigate the sub-Fourier behavior of a $\delta$-kicked rotor resonance by performing a measurement of the fidelity or overlap of a Bose-Einstein condensate (BEC) exposed to a periodically pulsed standing wave. The temporal width of the fidelity resonance peak centered at the Talbot time and zero initial momentum exhibits an inverse cube pulse number ($1/N^{3}$) dependent scaling compared to a $1/N^{2}$ dependence for the mean energy width at the same resonance. A theoretical analysis shows that for an accelerating potential the width of the resonance in acceleration space depends on $1/N^{3}$, a property which we also verify experimentally. Such a sub-Fourier effect could be useful for high precision gravity measurements.Comment: 4 pages, 5 figure

Fungi isolated from Miscanthus and sugarcane: biomass conversion, fungal enzymes, and hydrolysis of plant cell wall polymers.

BackgroundBiofuel use is one of many means of addressing global change caused by anthropogenic release of fossil fuel carbon dioxide into Earth's atmosphere. To make a meaningful reduction in fossil fuel use, bioethanol must be produced from the entire plant rather than only its starch or sugars. Enzymes produced by fungi constitute a significant percentage of the cost of bioethanol production from non-starch (i.e., lignocellulosic) components of energy crops and agricultural residues. We, and others, have reasoned that fungi that naturally deconstruct plant walls may provide the best enzymes for bioconversion of energy crops.ResultsPreviously, we have reported on the isolation of 106 fungi from decaying leaves of Miscanthus and sugarcane (Appl Environ Microbiol 77:5490-504, 2011). Here, we thoroughly analyze 30 of these fungi including those most often found on decaying leaves and stems of these plants, as well as four fungi chosen because they are well-studied for their plant cell wall deconstructing enzymes, for wood decay, or for genetic regulation of plant cell wall deconstruction. We extend our analysis to assess not only their ability over an 8-week period to bioconvert Miscanthus cell walls but also their ability to secrete total protein, to secrete enzymes with the activities of xylanases, exocellulases, endocellulases, and beta-glucosidases, and to remove specific parts of Miscanthus cell walls, that is, glucan, xylan, arabinan, and lignin.ConclusionThis study of fungi that bioconvert energy crops is significant because 30 fungi were studied, because the fungi were isolated from decaying energy grasses, because enzyme activity and removal of plant cell wall components were recorded in addition to biomass conversion, and because the study period was 2 months. Each of these factors make our study the most thorough to date, and we discovered fungi that are significantly superior on all counts to the most widely used, industrial bioconversion fungus, Trichoderma reesei. Many of the best fungi that we found are in taxonomic groups that have not been exploited for industrial bioconversion and the cultures are available from the Centraalbureau voor Schimmelcultures in Utrecht, Netherlands, for all to use

Water Availability Under Future Climate Change: A Study of Citarum River Basin, Indonesia

This study assessed the impact of climate change on future water availability in the Citarum river basin, Indonesia. Future climate was projected based on the output of HadCM3 GCM under A2 and B2 scenarios and downscaled using SDSM package application. The hydrological processes were modelled using WEAP application. The result suggested an increase of temperature as well as precipitation in the period of the 2020s, 2050s and 2080s. The water availability is projected to increase in the future.

A Principal-Agent Theory Perspective on PPP Risk Allocation

This study proposes a framework for the allocation of risk in public private partnerships (PPP) projects. Its contribution lies in the recognition and incorporation of risks introduced by project stakeholders, and as articulated by the principal-agent theory (PAT). The framework assesses risks and routes these risks to those parties best equipped to mitigate their impact on the project. This allocation of risk is facilitated by a thirteen-step process. The practical benefit of this study lies in outlining a clear, systematic method for allocating risk efficiently to both the government and private enterprise parties of the project. In so doing, risk mitigation can be expected to improve project performance, optimize stakeholder goals, and enhance sustainability objectives, including improved operational life-cycle efficiency and elevated social and community benefits

Hepatitis E virus in the Kathmandu Valley: Insights from a representative longitudinal serosurvey

BackgroundHepatitis-E virus (HEV), an etiologic agent of acute inflammatory liver disease, is a significant cause of morbidity and mortality in South Asia. HEV is considered endemic in Nepal; but data on population-level infection transmission is sparse.MethodsWe conducted a longitudinal serosurvey in central Nepal to assess HEV exposure. At each visit, capillary blood samples were collected and analyzed for the presence of anti-HEV IgG antibodies. The study took place between February 2019 and April 2021, with up to 4 visits per participant approximately 6 months apart.ResultsWe collected 2513 samples from 923 participants aged 0-25 years, finding a seroprevalence of 4.8% and a seroincidence rate of 10.9 per 1000 person-years. Young adults and individuals consuming surface water faced the highest incidence of infection. Geospatial analysis identified potential HEV clusters, suggesting a need for targeted interventions.SignificanceOur findings demonstrate that HEV is endemic in Nepal and that the risk of infection increases with age

Rapid silviculture appraisal to characterise stand and determine silviculture priorities of community forests in Nepal

Published online: 7 September 2016Community forestry in Nepal is an example of a successful participatory forest management program. Developments in community forestry in four decades have focused on the social and governance aspects with little focus on the technical management of forests. This paper presents a silviculture description of community forests and provides silviculture recommendations using a rapid silviculture appraisal (RSA) approach. The RSA, which is a participatory technique involving local communities in assessing forests and silviculture options, is a simple and costeffective process to gather information and engage forest users in the preparation of operational plans that are relevant to their needs. The RSA conducted on selected community forests in Nepal’s Mid-hills region shows that forests are largely comprised of dominant crowns of one or two species. The majority of studied community forests have tree densities below 500 stems per hectare as a consequence of traditional forest management practices but the quality and quantity of the trees for producing forest products are low. Silviculture options preferred by forest users generally are those which are legally acceptable, doable with existing capacities of forest users and generate multiple forest products. For sustainable production of multiple forest products, the traditional forest management practices have to be integrated with silviculture-based forest management system.Edwin Cedamon, Ian Nuberg, Govinda Paudel, Madan Basyal, Krishna Shrestha, Naya Paude

Formulation and Characterization of Phytostanol Ester Solid Lipid Nanoparticles for the Management of Hypercholesterolemia: An ex vivo Study.

Background: Phytostanols are naturally occurring compounds that reduce blood cholesterol levels significantly. However, their aqueous insolubility poses formulation challenges. Aim: To formulate and characterize solid lipid nanoparticle carriers for phytostanol esters to enhance the bioavailability of phytostanols. Methods: Phytostanol ester solid lipid nanoparticles were formulated by the microemulsion method. They were characterized for particle size distribution, polydispersity index, shape, surface charge, entrapment efficiency, stability, chemical structure, and thermal properties. The uptake of the formulation by cell lines, HepG2 and HT-29, and its effect on cell viability were evaluated. Results: The formulation of solid lipid nanoparticles was successfully optimised by varying the type of lipids and their concentration relative to that of surfactants in the present study. The optimised formulation had an average diameter of (171 ± 9) nm, a negative surface charge of (− 23.0 ± 0.8) mV and was generally spherical in shape. We report high levels of drug entrapment at (89 ± 5)% in amorphous form, drug loading of (9.1 ± 0.5)%, nanoparticle yield of (67 ± 4)% and drug excipient compatibility. The biological safety and uptake of the formulations were demonstrated on hepatic and intestinal cell lines. Conclusion: Phytostanol ester solid lipid nanoparticles were successfully formulated and characterized. The formulation has the potential to provide an innovative drug delivery system for phytostanols which reduce cholesterol and have a potentially ideal safety profile. This can contribute to better management of one of the main risk factors of cardiovascular disease

Optimising the observation of optical kilonovae with medium size telescopes

We consider the optimisation of the observing strategy (cadence, exposure time and filter choice) using medium size (2-m class) optical telescopes in the follow-up of kilonovae localised with arcminute accuracy to be able to distinguish among various kilonova models and viewing angles. To develop an efficient observation plan, we made use of the synthetic light curves obtained with the Monte Carlo radiative transfer code POSSIS for different kilonova models and as a function of different viewing angles and distances. By adding the appropriate photon counting noise to the synthetic light curves, we analysed four alternative sequences having the same total time exposure of 8 hours, with different time windows (0.5, 1, 2, 4 h), each with $i$, $r$, and $u$ filters, to determine the observing sequence that maximises the chance of a correct identification of the model parameters. We suggest to avoid $u$ filter and to avoid the use of colour curves. We also found that, if the error on distance is $\le$ 2%, 0.5, 1, 2-hour time window sequences are equivalent, so we suggest to use 2-hour one, because it has 1 day cadence, so it can be easily realised. When the distance of the source is unknown, 0.5 h time window sequence is preferable.Comment: 9 pages, 8 figures, published in MNRA