bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural and functional analysis of tomato β‐galactosidase 4: insight into the substrate specificity of the fruit softening‐related enzyme
Authors: Eda Masahiro , Matsumoto Takashi , Ishimaru Megumi , Tada Toshiji 
Published: March 2016

SummaryPlant β‐galactosidases hydrolyze cell wall β‐(1,4)‐galactans to play important roles in cell wall expansion and degradation, and turnover of signaling molecules, during ripening. Tomato β‐galactosidase 4 (TBG4) is an enzyme responsible for fruit softening through the degradation of β‐(1,4)‐galactan in the pericarp cell wall. TBG4 is the only enzyme among TBGs 1–7 that belongs to the β‐galactosidase/exo‐β‐(1,4)‐galactanase subfamily. The enzyme can hydrolyze a wide range of plant‐derived (1,4)‐ or 4‐linked polysaccharides, and shows a strong ability to attack β‐(1,4)‐galactan. To gain structural insight into its substrate specificity, we determined crystal structures of TBG4 and its complex with β‐d‐galactose. TBG4 comprises a catalytic TIM barrel domain followed by three β‐sandwich domains. Three aromatic residues in the catalytic site that are thought to be important for substrate specificity are conserved in GH35 β‐galactosidases derived from bacteria, fungi and animals; however, the crystal structures of TBG4 revealed that the enzyme has a valine residue (V548) replacing one of the conserved aromatic residues. The V548W mutant of TBG4 showed a roughly sixfold increase in activity towards β‐(1,6)‐galactobiose, and ~0.6‐fold activity towards β‐(1,4)‐galactobiose, compared with wild‐type TBG4. Amino acid residues corresponding to V548 of TBG4 thus appear to determine the substrate specificities of plant β‐galactosidases towards β‐1,4 and β‐1,6 linkages.
Treatment with oestrogen‐receptor agonists or oxytocin in conjunction with exercise protects against myocardial infarction in ovariectomized rats
Authors: Bulut Erman Caner , Abueid Leyla , Ercan Feriha , Süleymanoğlu Selami , Ağırbaşlı Mehmet , Yeğen Berrak Ç. 
Published: March 2016

New Findings

What is the central question of this study?
Could the activation of oxytocin or oestrogen receptors be protective against myocardial injury after ovariectomy? If so, would exercising have an additional ameliorating effect?

What is the main finding and its importance?
The results revealed that when accompanied by exercise, both oestrogen receptor agonists and oxytocin improved cardiac dysfunction, inhibited the generation of pro‐inflammatory cytokines and reduced myocardial injury in ovariectomized female rats, suggesting a new approach for protecting postmenopausal women against ischaemia‐induced myocardial injury.

To investigate the putative protective effects of oxytocin or oestrogen receptor agonists against myocardial injury of ovariectomized sedentary or exercised rats, female Sprague–Dawley rats assigned to sham‐operated control and ovariectomized (OVX) groups were kept sedentary or undertook swimming exercise for 4 weeks and were treated with saline, an oestrogen receptor (ER) β (DPN) or ERα agonist (PPT) or oxytocin. Ovariectomy increased weight gain and anxiety in sedentary rats, whereas exercise prevented weight gain. When accompanied by exercise, both ER agonists and oxytocin inhibited weight gain and anxiety; oxytocin, in the absence or presence of exercise, increased the left ventricular diastolic dimensions and ejection fraction, whereas ER agonists also increased left ventricular diameter when given to exercised rats. Upon the induction of myocardial ischaemia–reperfusion in the OVX rats, plasma creatine kinase‐(muscle–brain) was depressed by PPT and oxytocin, whereas DPN, PPT and OT reduced plasminogen activator inhibitor‐1 concentrations. The increased tumour necrosis factor‐α concentration in OVX rats was also suppressed by exercise or DPN, PPT or oxytocin treatments, whereas the interleukin‐6 concentration was diminished by all the treatments when given in conjunction with exercise. Disorganization of cardiac muscle fibres was reduced in all exercised rats. Oestrogen receptor agonists, as well as oxytocin, in conjunction with exercise may be effective new therapeutics to protect against myocardial ischaemia in postmenopausal women.
Local District Heating Network With a Small-Scale Trigeneration Plant: Energetic and Economic Analysis of Optimization Strategies
Authors: Amoruso Gabriele , Badami Marco , Portoraro Armando 
Published: March 2016

District heating networks, integrated with cogeneration plants, allow primary energy savings to be obtained compared to traditional heat-generation systems. However, the management of these plants in residential applications is a complex issue, because of the fluctuations in the thermal users’ daily profiles. The proper operation of these plants therefore becomes of utmost importance in order to avoid energy dissipations and with a consequent economic profitability loss.
The paper has the aim of illustrating the experimental data of a real, local district heating network coupled to a trigeneration plant installed and in operation in Turin, Italy. The main technical characteristics of the installation are described, and the present operational strategies are presented and discussed. The study focuses on the analysis of several possible optimizations of these strategies, and the increase in energy efficiency that can be obtained for each of them, taking into account the thermal losses over the heating grid. A comparative economic analysis has also been carried out in order to highlight the effect of these optimizations on the economic profitability of the installation. The results of the study are presented in detail and discussed in the paper.
Feasibility of Using More Geothermal Energy to Generate Electricity
Authors: Wong Kaufui Vincent , Tan Nathanael 
Published: March 2016

Human population is ever-increasing and thus, demand for energy is escalating. Consequently, seeking clean methods of producing electricity is a most crucial endeavor at this time. The shrinking reserves of oil have added urgency to the matter. One other recognized source of renewable energy besides wind, water and solar (WWS) is geothermal energy, which has been proven to be useful in baseload power generation, a significant advantage over WWS. As compared to fossil fuels, geothermal energy is not subjected to the supply and cost fluctuations of which fuels are at risk.
To date, there have been a number of innovative procedures explored to use geothermal energy to produce electricity. A relatively innovative yet not uncommon method has been to use hot solid rocks to heat water and pump the superheated water to use in power plants. These rocks are generally underground and at higher temperatures due to their proximity to volcanoes or natural geothermal vents. The water goes deeper down into the earth’s crust to become superheated by the rocks, and then is pumped out to power turbines, and subsequently returned into the ground to repeat the process.
In Krafla, Iceland, during their Icelandic Deep Drilling Project (IDDP) in 2009, a borehole was accidentally dug into the magma at 2100 meters. The temperature of this magma was about 900–1000°C. A steel casing with perforations on the flat side was cemented into the well bottom. This design was to slow the heat flow, and superheated steam was made for the following two years till July 2012. The steam reached temperatures of 450°C and was at high pressures. Krafla was the world’s first magma-enhanced geothermal system to generate electricity.
This paper will explore the feasibility of using geothermal power plant methods as a sustainable source of clean energy. Geothermal energy has tremendous potential if the right methods can be found to tap that potential, as well as if the cost may be brought down by innovation and demand. In addition, an innovative method which already exists in some form, is proposed in the current review, to harness more geothermal energy for use.
Available Systems for the Conversion of Waste Heat to Electricity
Authors: Tauveron N. , Colasson S. , Gruss J.-A. 
Published: March 2016

The conversion of heat into electricity, generally speaking heat-to-power generation, is a wide area of technologies and applications. This paper focuses on available systems, excepted the internal combustion cycles, applied to transform (waste) heat to power. Data of referenced market proved or time-to-market technologies are presented. A database of more than 1100 references has been built. The following categories can be found: Rankine Cycle plant, Organic Rankine Cycle plant, Steam engine, Kalina Cycle plant, Brayton cycle plant, micro gas turbine, closed cycle gas turbine plant, combined cycle gas turbine plant, Stirling engine, Ericsson engine and thermoelectric generator. We intentionally target a range of power from Watts to hundreds of MW, covering the range of temperature [80–1000°C] usually addressed by these systems.
The comparison of performances is hereby discussed and compared to thermodynamic principles and theoretical results in the graph Maximum temperature [°C] versus Thermodynamic efficiency. Comparison with Carnot and Chambadal-Novikov-Curzon-Ahlborn efficiencies are performed.
A more original contribution is the presentation of the graph Power [W] versus Thermodynamic efficiency. The analysis reveals a monotonous trend inside each technology. Furthermore this general behavior covers a very wide range of power, including technological transitions.
Finally, the position of each technology in the map Maximum temperature [°C] versus Power [W] is also analyzed. Explanations based on thermodynamics and techno-economic approaches are proposed.
Integration of a CaO-Based Thermal Storage System in an IGCC Plant With Carbon Capture
Authors: Vandersickel Annelies , Mitsos Alexander , Field Randall P. 
Published: March 2016

Using pre-combustion CO2-capture, IGCC plants show significant potential for efficient power generation with carbon capture. The gasification and gas processing steps however have multiple temperature and flow constraints which severely limit the flexibility of IGCC plants to meet the dynamic demands of the current grid. To address this issue, a CaO-based energy storage system has recently been proposed to substantially increase the load range of a base IGCC plant without cycling the gasifier island.
In this work, further storage configurations have been assessed, addressing the inefficiencies identified in previous work. In particular, the following cases have been investigated: directly fired calciners with varying make-up flow rate to minimize the purge stream energy loss, directly fired calciners with improved heat integration to reduce the calciner syngas demand and an indirectly fired calciner to minimize the ASU penalty. Additionally, an alternative storage integration strategy after the Selexol unit has been compared both with respect to its performance and its impact on the base IGCC plant design and operation. To this end, process simulation was undertaken in Aspen Plus™. As demonstrated, the CaO based energy storage system can be effectively used to modulate the IGCC net power output by ±20–25%, while maintaining the capture capacity of 90% of the CO2-emissions. Improvement of the particle reactivity and the internal heat recuperation were found to impact the round-trip efficiency the most.
Reduction of Primary Energy Consumption Through Distributed Thermal Storage in Buildings Connected With a District Heating Network
Authors: Baccino Giorgia , Cosentino Sara , Guelpa Elisa , Sciacovelli Adriano , Verda Vittorio 
Published: March 2016

One of the possible options for increasing the primary energy efficiency in district heating networks (DHNs) consists in flattening the thermal load diagram of the plants. This can be obtained through thermal storage. Storage generally allows one to increase the percentage of heat produced through CHP plants, waste heat or renewable systems.
In this work, a numerical approach to analyze possible effects of distributed storage on the primary energy consumption is presented. This is based on the availability of detailed information about the thermal substations that connect the users to the DHN and a thermo-fluid dynamic model of the network. First, the analysis of a user of the district heating network is proposed in order to show the operating conditions of the heat exchanger in the thermal substation. Then the model of the network is presented and an application is proposed. This application allows us to discuss how the thermal request of a user modifies along the network because of the heat capacity of the network itself and mixing with the mass flow rates at different temperatures. Therefore, the thermal load that the plants should fulfill is different than the simple summation of the thermal request of the users.
This tool allows one to link the thermal thermal request of the users to the thermal load of the plant and thus to the global primary energy consumption. It can be then applied to the evaluation of possible variation of thermal request profile of the users.
Pumping System Assessment in Water Treatment Plants: Case Study: Mexicali, Baja California, México
Authors: Gil Samaniego Ramos Margarita , Campbell Ramírez Héctor Enrique , León Silvia Vanessa Medina , Corral Juan Ceballos 
Published: March 2016

Energy and hydraulic efficiency are important goals for the sustainable development of water supply systems.
The objective of these systems is to guarantee the delivery of enough water with good quality to populations. Although in order to achieve that, energy for pumping is needed, representing the main cost for the companies to operate the systems, since the energy costs vary with the amount of pumped water and the daily energy tariff.
Water and energy are critical resources that affect virtually all aspects of daily life. Ensuring these resources are available in sufficient quantities when and where society needs them entails significant investments in planning, infrastructure development, operations and maintenance bills.
Ever-increasing utility costs reduce profits, erode capital and maintenance budgets, increase product costs, and reduce competitiveness.
Pumping systems are critically important to the operations of a water treatment plant. The amount of energy consumed by many long-running pumping systems often results in a substantial addition to a plant’s annual operation costs. Therefore, these systems are a natural target to reduce energy consumption. Producers and users of pumps must design highly efficient pumping systems. The efficiency of these systems must be evaluated involving the multiple factors that often are difficult to understand for many users, consequently they overlook the energy costs and energy reduction potential on these systems. Methodologies that can maximize energy cost savings while satisfying system performance criteria should be sought for the design and management of the water distribution systems.
This paper compares operating characteristic curves (OC curves) from a pump manufacturer with the curves obtained with field data, and evaluates the efficiency of the pumping system of raw water of a water treatment plant in Mexicali, Baja California, México, which consists on a group of parallel identical pumps. The assessment also analyses the potential savings in costs and emissions of GHG related to the energy consumption of the pumping system if the operation conditions were the optimal, with the objective of minimize negative effects to the sustainable development of the region. Measurements of hydraulic and electrical parameters of the pumping system were made and efficiencies calculated. Actual characteristic operation curves were plotted and compared to those from the pump’s manufacturer and up to 31% (average) difference in the efficiencies was found. Also emission factors of the electrical generation system of the state were applied to obtain the amounts of actual GHG emissions due to the operation of the pumps. The software PSAT was used to compute potential annual savings in MWh and costs and the results employed to calculate possible reduction in emissions.
Optimal Operation and Sensitivity Analysis of a Large District Heating Network Through POD Modeling
Authors: Cosentino Sara , Guelpa Elisa , Melli Roberto , Sciacovelli Adriano , Sciubba Enrico , Toro Claudia , Verda Vittorio 
Published: March 2016

District heating networks (DHNs) are crucial infrastructures for the implementation of energy efficiency and CO2 reduction plans, especially in countries with continental climate. DHNs are often complex systems and their energy performance may be largely affected by the operating conditions.
Optimal operation of DHNs involves the optimization of the pumping system. This is particularly important for large networks and for low temperature networks. A common practice to perform optimization consists in using a phyical model. Nevertheless, simulation and optimization of DHNs may involve large computational resources, because of thire possible large extension and the number of scenarios to be examined. A reduced model, obtained from the physical model, can be effectively applied to multiple simulations of a network, with significant reduction of the computational time and resources.
In this paper, a large district heating system, which supplies heating to a total volume of buildings of about 50 million of cubic meters, is considered. The use of a reduced model based on proper orthogonal decomposition (POD) is investigated. Various operating conditions corresponding to partial load operation are analyzed using a fluid-dynamic model of the network. Results show that optimal settings are not particularly regular with respect to load variation. This means that any variation in the thermal load generally involves changes in the set points of all groups. For this reason, a sensitivity analysis is performed using the POD model in order to check the opportunities to limit the number of variations in the pumping settings without significant penalization of the total pumping power.
The proposed approach is shown to be very effective for the optimal management of complex district heating systems.
Delineation of Steroid-Degrading Microorganisms through Comparative Genomic Analysis
Authors: Bergstrand Lee H. , Cardenas Erick , Holert Johannes , Van Hamme Jonathan D. , Mohn William W. 
Published: March 2016

ABSTRACT

Steroids are ubiquitous in natural environments and are a significant growth substrate for microorganisms. Microbial steroid metabolism is also important for some pathogens and for biotechnical applications. This study delineated the distribution of aerobic steroid catabolism pathways among over 8,000 microorganisms whose genomes are available in the NCBI RefSeq database. Combined analysis of bacterial, archaeal, and fungal genomes with both hidden Markov models and reciprocal BLAST identified 265 putative steroid degraders within only
Actinobacteria
and
Proteobacteria
, which mainly originated from soil, eukaryotic host, and aquatic environments. These bacteria include members of 17 genera not previously known to contain steroid degraders. A pathway for cholesterol degradation was conserved in many actinobacterial genera, particularly in members of the
Corynebacterineae
, and a pathway for cholate degradation was conserved in members of the genus
Rhodococcus
. A pathway for testosterone and, sometimes, cholate degradation had a patchy distribution among
Proteobacteria
. The steroid degradation genes tended to occur within large gene clusters. Growth experiments confirmed bioinformatic predictions of steroid metabolism capacity in nine bacterial strains. The results indicate there was a single ancestral 9,10-seco-steroid degradation pathway. Gene duplication, likely in a progenitor of
Rhodococcus
, later gave rise to a cholate degradation pathway.
Proteobacteria
and additional
Actinobacteria
subsequently obtained a cholate degradation pathway via horizontal gene transfer, in some cases facilitated by plasmids. Catabolism of steroids appears to be an important component of the ecological niches of broad groups of
Actinobacteria
and individual species of
Proteobacteria
.

IMPORTANCE
Steroids are ubiquitous growth substrates for environmental and pathogenic bacteria, and bacterial steroid metabolism has important pharmaceutical and health applications. To date, the genetics and biochemistry of microbial steroid degradation have mainly been studied in a few model bacteria, and the diversity of this metabolism remains largely unexplored. Here, we provide a bioinformatically derived perspective of the taxonomic distribution of aerobic microbial steroid catabolism pathways. We identified several novel steroid-degrading bacterial groups, including ones from marine environments. In several cases, we confirmed bioinformatic predictions of metabolism in cultures. We found that cholesterol and cholate catabolism pathways are highly conserved among certain actinobacterial taxa. We found evidence for horizontal transfer of a pathway to several proteobacterial genera, conferring testosterone and, sometimes, cholate catabolism. The results of this study greatly expand our ecological and evolutionary understanding of microbial steroid metabolism and provide a basis for better exploiting this metabolism for biotechnology.
Family income and young adolescents’ perceived social position: associations with self-esteem and life satisfaction in the UK Millennium Cohort Study
Authors: Bannink Rienke , Pearce Anna , Hope Steven 
Published: March 2016

BackgroundSelf-esteem and life satisfaction are important aspects of positive mental health in young people, and both are socially distributed. However, the majority of evidence is based on socioeconomic characteristics of the family. As children enter adolescence and gain independence, perceptions of their own social position are likely to influence mental health.Design and objectivesUsing data on 11-year-olds from the UK Millennium Cohort Study, we investigated associations of both family income and young adolescents’ perception of their social position with self-esteem and life satisfaction. We hypothesised that there would be differences in the impact of perceived social position on positive mental health when investigating the full scale scoring distribution or the bottom of the distribution. Therefore, we estimated proportional odds for having greater positive mental health (across the distribution of scores) and ORs for poor outcomes (lowest 10% scores).ResultsThe likelihood of greater self-esteem and life satisfaction increased with income; similarly, the risk of having poor self-esteem and life satisfaction increased as income decreased. Young adolescents who perceived their family as poorer than their friends (instead of about the same) were less likely to have greater self-esteem and life satisfaction and were more likely to have poor outcomes. Young adolescents who perceived their family as richer were more likely to have poor self-esteem, but were not less likely to have greater self-esteem. For life satisfaction, young adolescents who perceived their families as richer were less likely to have greater and more likely to have poor life satisfaction.ConclusionsPolicies to redistribute income in families with children are likely to benefit the mental health of young people. However, it is also important to consider the impact of social comparison on young people's mental health as they enter adolescence.