bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Dietary Ascorbic Acid on Growth Performance, Body Composition, and Some Immunological Parameters of Caspian Brown Trout, Salmo trutta caspius
Authors: Arab Narges , Rajabi Islami Houman
Published: October 2015

A 9‐wk feeding experiment was conducted to investigate the effect of dietary ascorbic acid (AA) on growth performance and tissue compositions of Caspian brown trout. The fish (9.64 ± 0.62 g) were held in tanks at a density of 40 fish per tank. Five experimental diets were prepared by providing of 9.8, 43.8, 89.4, 188.5, and 384.2 mg AA equivalent/kg diet, respectively. At the end of the trial, an increasing trend was found on growth performance with the increase of AA supplementation. Fish fed diet supplemented with more than 188.5 mg/kg AA also had significantly higher bone collagen than fish fed diets containing 9.8 mg/kg AA (P < 0.05). According to the broken line, the dietary AA requirement of Caspian brown trout fingerlings was 177.24 mg AA/kg diet based on the weight gain, 186.97 mg AA/kg diet based on the protein tissue, and 163.95 mg AA/kg diet based on the bone collagen. Serum lysozyme and alternative complement pathway activities were also influenced by graded level of AA supplementation to the diet. The present research clearly indicated that AA is required for normal growth and enhancement of immune response in Caspian brown trout fingerlings.
Effects of Water Hardness and Calcium: Magnesium Ratios on Reproductive Performance and Offspring Quality of Macrobrachium rosenbergii
Authors: Rezaei Tavabe Kamran , Rafiee Gholamreza , Shoeiry Mohammad Mehdi , Houshmandi Shadab , Frinsko Michael , Daniels Harry
Published: October 2015

This study evaluated the effect of specific calcium and magnesium ratios at two hardness values on reproductive performance and offspring quality of Macrobrachium rosenbergii brood‐females. Hatchery water containing 110.5 mg/L CaCO3 hardness was considered baseline as it has been used successfully to hatch and rear larvae and was used as the control treatment. At each hardness value of 150 and 190 mg/L CaCO3, four experimental water treatments were made in triplicate. Each treatment was adjusted using soluble salts (CaCl2·H2O, MgSO4·7H2O, and MgCl2·6H2O) to provide the hardness and calcium to magnesium ratios of 0:20, 20:80, 50:50, and 80:20 needed. Each of the experimental tanks (140 L) were stocked with six females and one male. The results indicated that both hardness and Ca:Mg ratios affect brood‐female reproductive qualitative parameters such as intermolt period, egg hatchability, egg dry weight, and egg‐clutch somatic index (ESI) parameters (P < 0.05) but not fecundity and eggs per spawn. The results revealed that brood‐females at 150 mg/L hardness showed greater reproductive performance than at 190 and 110.5 mg/L hardness. The findings also demonstrated that the treatment 50Ca50Mg at 150 mg/L hardness with 38.8 mg/L calcium and 12.9 mg/L magnesium had optimum reproductive performance and offspring quality for M. rosenbergii brood‐females.
Influence of education and diagnostic modes on glaucoma assessment by optometrists
Authors: Yoshioka Nayuta , Wong Elizabeth , Kalloniatis Michael , Yapp Michael , Hennessy Michael P. , Agar Ashish , Healey Paul R. , Hayen Andrew , Zangerl Barbara
Published: October 2015

Purpose

To evaluate the influence of different clinical examination techniques, including optic nerve head (ONH) photography, visual field tests, and adjunct imaging on the diagnosis of glaucoma by Australian and New Zealand optometrists. The effect of a short‐term, didactic teaching module on these is also explored.

Methods

Clinical data of 30 patients previously seen at the Centre for Eye Health was collected and compiled into glaucoma diagnostic assessment modules. Each of six modules contained different combinations of clinical examination results and required a classification of the cases as normal, suspicious or glaucoma. A cohort of 54 Australian and New Zealand optometrists were recruited for the study and allocated into two cohorts. The intervention group completed a glaucoma training course prior to the assessment while the control group completed the assessment without additional training. Diagnostic accuracy was compared between modules and optometrist groups.

Results

High false negative rates were observed with ONH photography, which were drastically reduced with the addition of visual field, albeit at the cost of increased false positive rates. Addition of adjunct imaging techniques partially compensated for the increase in the false positive rate from the visual field, but had limited effect on false negative rate. Educational intervention resulted in larger improvement in the diagnostic ability when multiple imaging modalities were provided.

Conclusion

The study highlighted the importance of combining both structural and functional assessments in glaucoma. Current imaging technology demonstrated limited usefulness for event diagnosis due to the persistent difficulties of defining structural and functional loss in glaucoma, thus highlighting the need for new glaucoma assessment techniques. Short‐term didactic teaching programs may only result in limited improvement of glaucoma diagnostic ability in optometrists, and hence, it may need to be combined with long‐term and/or non‐didactic training components to obtain a greater effect.
Paperless anesthesia: uses and abuses of these data
Authors: Anderson Brian J. , Merry Alan F.
Published: October 2015

Demonstrably accurate records facilitate clinical decision making, improve patient safety, provide better defense against frivolous lawsuits, and enable better medical policy decisions. Anesthesia Information Management Systems (AIMS) have the potential to improve on the accuracy and reliability of handwritten records. Interfaces with electronic recording systems within the hospital or wider community allow correlation of anesthesia relevant data with biochemistry laboratory results, billing sections, radiological units, pharmacy, earlier patient records, and other systems. Electronic storage of large and accurate datasets has lent itself to quality assurance, enhancement of patient safety, research, cost containment, scheduling, anesthesia training initiatives, and has even stimulated organizational change. The time for record making may be increased by AIMS, but in some cases has been reduced. The question of impact on vigilance is not entirely settled, but substantial negative effects seem to be unlikely. The usefulness of these large databases depends on the accuracy of data and they may be incorrect or incomplete. Consequent biases are threats to the validity of research results. Data mining of biomedical databases makes it easier for individuals with political, social, or economic agendas to generate misleading research findings for the purpose of manipulating public opinion and swaying policymakers. There remains a fear that accessibility of data may have undesirable regulatory or legal consequences. Increasing regulation of treatment options during the perioperative period through regulated policies could reduce autonomy for clinicians. These fears are as yet unsubstantiated.
Gender aspects of recreational sun‐protective behavior: results of a representative, population‐based survey among Austrian residents
Authors: Haluza Daniela , Simic Stana , Höltge Jan , Cervinka Renate , Moshammer Hanns
Published: October 2015

Purpose

Lifetime risk for melanoma skin cancer is enlarged by sunlight exposure and reduced by sun protection. Austrian melanoma incidence and mortality rates are constantly rising with higher rates in males. Thus, we aimed at investigating gender‐specific recreational sun exposure habits among the Austrian population.

Methods

We conducted a telephone survey among 1500 adults (50.5% females) representing sociodemographic characteristics of the Austrian population. Using a structured questionnaire, we studied gender‐specific sun exposure‐related knowledge, motives to tan, and behavior.

Results

Overall, using sunscreen, wearing sunglasses, and seeking shade were among the three most frequent sun safe measures. Basic skin health knowledge and tanning motives were similar among genders, although females protected themselves more. In general, sunburn occurrence (odds ratio [OR] = 1.4, 95% confidence interval [CI] = 1.0–1.8), skin type IV (OR = 2.4, 95% CI = 1.3–4.5), ex‐/non‐smoking (OR = 1.4–1.6, 95% CI = 1.0–2.1), low motives to tan (both OR = 1.3, 95% CI = 1.0–1.7), no outdoor sport (OR = 1.3, 95% CI = 1.0–1.7), all P < 0.05, as well as the use of sunscreen with lower SPF values (OR = 1.0–3.0, 95% CI = 1.4–4.3) and male gender (OR = 1.6, 95% CI = 1.2–2.0), both P < 0.001, increased the odds of practicing low sun protection.

Conclusion

The results of this investigation suggest considering gender specificity when planning Public (Skin) Health‐related educative campaigns and programs, for example, by highlighting the appearance‐related benefits of sun light avoidance.
Metal oxide sunscreens protect skin by absorption, not by reflection or scattering
Authors: Cole Curtis , Shyr Thomas , Ou‐Yang Hao
Published: October 2015

Background/Purpose

The inorganic metal oxide sunscreens titanium dioxide and zinc oxide have been considered to protect against sunburning ultraviolet radiation by physically reflecting/scattering the incident photons and thus protecting the skin. Earlier publications suggested, however, that the primary action of UV protection by these sunscreen agents is through absorption and not by reflection. The purpose of this work was to quantitate the contributions of each of these modes of action to the protection provided by inorganic UV sunscreen filters.

Methods

An optical integrating sphere was used to measure the transmission and the reflectance of titanium dioxide and zinc oxide.

Results

The average range of reflection for zinc oxide and titanium dioxide throughout the UV range was only 4–5% (less than SPF 2), providing minimal UV protection via this mechanism. The remainder of the UV protection is provided by semiconductor band gap mediated absorbance of the UV photons. At wavelengths above the semiconductor band gap absorption energy levels (in the long UVA and visible wavelengths), they are predominantly reflectors of light (up to 60% reflection) and non‐absorbing.

Conclusion

Titanium dioxide and zinc oxide provide UV protection primarily via absorption of UV radiation and not through significant reflection or scattering.
Screening young athletes for prevention of sudden cardiac death: Practical recommendations for sports physicians
Authors: Chatard J.‐C. , Mujika I. , Goiriena J. J. , Carré F.
Published: October 2015

Regular intensive exercise in athletes increases the relative risk of sudden cardiac death (SCD) compared with the relatively sedentary population. Most cases of SCD are due to silent cardiovascular diseases, and pre‐participation screening of athletes at risk of SCD is thus of major importance. However, medical guidelines and recommendations differ widely between countries. In Italy, the National Health System recommends pre‐participation screening for all competitive athletes including personal and family history, a physical examination, and a resting 12‐lead electrocardiogram (ECG). In the United States, the American College of Cardiology and the American Heart Association recommend a pre‐participation screening program limited to the use of specific questionnaires and a clinical examination. The value of a 12‐lead ECG is debated based on issues surrounding cost‐efficiency and feasibility. The aim of this review was to focus on (i) the incidence rate of cardiac diseases in relation to SCD; (ii) the value of conducting a questionnaire and a physical examination; (iii) the value of a 12‐lead resting ECG; (iv) the importance of other cardiac evaluations in the prevention of SCD; and (v) the best practice for pre‐participation screening.
Responses of peripheral blood mononuclear cells to moderate exercise and hypoxia
Authors: Morabito C. , Lanuti P. , Caprara G. A. , Guarnieri S. , Verratti V. , Ricci G. , Catizone A. , Marchisio M. , Fanò‐Illic G. , Mariggiò M. A.
Published: October 2015

The purpose of this study was to analyze the physiological features of peripheral blood mononuclear cells (PBMCs) isolated from healthy female trekkers before and after physical activity carried out under both normoxia (low altitude, < 2000 m a.s.l.) and hypobaric hypoxia (high altitude, > 3700 m a.s.l.). The experimental design was to differentiate effects induced by exercise and those related to external environmental conditions. PBMCs were isolated from seven female subjects before and after each training period. The PBMCs were phenotypically and functionally characterized using fluorimetric and densitometric analyses, to determine cellular activation, and their intracellular Ca2+ levels and oxidative status. After a period of normoxic physical exercise, the PBMCs showed an increase in fully activated T lymphocytes (CD3+CD69+) and a reduction in intracellular Ca2+ levels. On the other hand, with physical exercise performed under hypobaric hypoxia, there was a reduction in T lymphocytes and an increase in nonactivated B lymphocytes, accompanied by a reduction in O2− levels in the mitochondria. These outcomes reveal that in women, low‐ to moderate‐intensity aerobic trekking induces CD69 T cell activation and promotes anti‐stress effects on the high‐altitude‐induced impairment of the immune responses and the oxidative balance.
Pseudotumoral presentation of fungating mycetoma caused by Phaeoacremonium fuscum in a renal transplant patient
Authors: McGrogan D. , David M.D. , Roberts C. , Borman A.M. , Nath J. , Inston N.G. , Mellor S.
Published: October 2015

Eumycetoma is an unusual infection in immunocompromised patients outside the tropics, caused by a variety of fungal pathogens. We describe the case of a 51‐year‐old renal transplant recipient who presented with a large pseudotumoral foot lesion necessitating complete surgical excision of the lesion. Cultures and molecular diagnosis confirmed Phaeoacremonium fuscum. This is the first case, to our knowledge, of fungating mycetoma caused by this fungal species in a solid organ transplant recipient.
Seeing Cooperation or Competition: Ecological Interactions in Cultural Perspectives
Authors: ojalehto bethany l. , Medin Douglas L. , Horton William S. , Garcia Salino G. , Kays Estefano G.
Published: October 2015

Do cultural models facilitate particular ways of perceiving interactions in nature? We explore variability in folkecological principles of reasoning about interspecies interactions (specifically, competitive or cooperative). In two studies, Indigenous Panamanian Ngöbe and U.S. participants interpreted an illustrated, wordless nonfiction book about the hunting relationship between a coyote and badger. Across both studies, the majority of Ngöbe interpreted the hunting relationship as cooperative and the majority of U.S. participants as competitive. Study 2 showed that this pattern may reflect different beliefs about, and perhaps different awareness of, plausible interspecies interactions. Further probes suggest that these models of ecological interaction correlate with recognition of social agency (e.g., communication, morality) in nonhuman animals. We interpret our results in terms of cultural models of nature and nonhuman agency.
Effect of patch size on seed removal by harvester ants
Authors: Torra J , Atanackovic V , Blanco‐Moreno J M , Royo‐Esnal A , Westerman P R
Published: October 2015

The harvester ant Messor barbarus can be responsible for high weed seed losses in dry land cereals in Spain. Because weeds occur in patches, harvester ants have to be able to find and exploit patches. However, seed patches can differ in size and may, therefore, differ in the probability of being discovered and exploited. Here, 90 patches varying in size from 0.25 to 9 m2 were created in three 50 × 50 m subareas in a cereal field. Oat seeds were sown as weed seed surrogates in the patches at 2000 seeds m−2. After 24 h, those remaining were collected and the exploitation rate (the percentage of seeds removed per patch discovered by ants) was estimated. Harvester ant nests and the location of the seed patches were georeferenced and used to estimate distances between them. The patch encounter rate (the proportion of patches discovered by the ants) decreased slightly, but significantly, with decreasing patch size, though not the exploitation rate, which was lowest in the smallest patches (78–94%) and highest in the largest (99–100%). Seed patches that were not found or partially exploited were mostly located in subareas with a lower ant nest density or a longer distance away from the nearest nest than seed patches that were fully exploited. The results of this study indicate that the interaction between the spatial distribution of ant nests and the patchy distribution of seeds can create opportunities for seeds to be subjected to lower levels of predation.
Modelling interactive effects of herbicide application timing and dose for the control of Bromus japonicus in wheat in an arid environment
Authors: Sarani M , Oveisi M , Rahimian Mashhadi H , Alizadeh H
Published: October 2015

Timely herbicide application is a key factor in herbicide efficiency that may provide some possibility of reducing herbicide dose. Field experiments were conducted to study the interactive effect of dose of the herbicide mesosulfuron‐methyl and application timing on the control of Bromus japonicas in wheat. Herbicide application timings were based on Zadoks growth stages of wheat. An empirical model was developed for deciding herbicide dose. Relationships between herbicide dose and weed biomass were described with the standard dose–response model at each application time. Parameter estimates suggested a linear increase in parameters W0 (weed biomass with no herbicide treatment) and ED50 (herbicide dose required for 50% reduction in W0) with thermal time. A combined dose–response (CDR) model, with W0 and ED50 being replaced by their linear relationships with thermal time, was used for weed biomass prediction. CDR was incorporated into the rectangular hyperbolic relationship to predict wheat yield with different herbicide doses and application timings simultaneously. The combined model was rearranged to give the minimum dose required to restrict weed competition and achieve an acceptable wheat yield. For example, to obtain a wheat grain yield of 4.4 kg h−1 (90% of the potential yield), the model suggests 75% of the recommended dose, if herbicide is applied prior to tillering. With delayed herbicide application to wheat jointing, the respective amount of wheat yield is achieved with herbicide rates higher than the recommended dose. The model developed in this study can be used to decide herbicide dose for controlling B. japonicus based on application timing.
A Global Dynamics Perspective for System Safety From Macro- to Nanomechanics: Analysis, Control, and Design Engineering
Authors: Rega Giuseppe , Lenci Stefano
Published: October 2015

The achievements occurred in nonlinear dynamics over the last 30 years entail a substantial change of perspective when dealing with vibration problems, since they are now deemed ready to meaningfully affect the analysis, control, and design of mechanical and structural systems. This paper aims at overviewing the matter, by highlighting and discussing the important, yet still overlooked, role that some relevant concepts and tools may play in engineering applications. Upon dwelling on such topical concepts as local and global dynamics, bifurcation and complexity, theoretical and practical stability, attractor robustness, basin erosion, and dynamical integrity, recent results obtained for a variety of systems and models of interest in applied mechanics and structural dynamics are overviewed in terms of analysis of nonlinear phenomena and their control. The global dynamics perspective permits to explain partial discrepancies between experimental and theoretical/numerical results based on merely local analyses and to implement effective dedicated control procedures. This is discussed for discrete systems and reduced order models of continuous systems, for applications ranging from macro- to micro/nanomechanics. Understanding of basic phenomena in nonlinear dynamics has now reached such a critical mass that it is time to exploit their potential to enhance the effectiveness and safety of systems in technological applications and to develop novel design criteria.
A New High-Temperature Gel for Profile Control in Heavy Oil Reservoirs
Authors: Wang Changjiu , Liu Huiqing , Zheng Qiang , Liu Yongge , Dong Xiaohu , Hong Cheng
Published: October 2015

Controlling the phenomenon of steam channeling is a major challenge in enhancing oil recovery of heavy oil reservoirs developed by steam injection, and the profile control with gel is an effective method to solve this problem. The use of conventional gel in water flooding reservoirs also has poor heat stability, so this paper proposes a new high-temperature gel (HTG) plugging agent on the basis of a laboratory experimental investigation. The HTG is prepared with nonionic filler and unsaturated amide monomer (AM) by graft polymerization and crosslinking, and the optimal gel formula, which has strong gelling strength and controllable gelation time, is obtained by the optimization of the concentration of main agent, AM/FT ratio, crosslinker, and initiator. To test the adaptability of the new HTG to heavy oil reservoirs and the performance of plugging steam channeling path and enhancing oil recovery, performance evaluation experiments and three-dimensional steam flooding and gel profile control experiments are conducted. The performance evaluation experiments indicate that the HTG has strong salt resistance and heat stability and still maintains strong gelling strength after 72 hrs at 200 °C. The singular sand-pack flooding experiments suggest that the HTG has good injectability, which can ensure the on-site construction safety. Moreover, the HTG has a high plugging pressure and washing out resistance to the high-temperature steam after gel forming and keeps the plugging ratio above 99.8% when the following steam injected volume reaches 10 PV after gel breakthrough. The three-dimensional steam flooding and gel profile control experiments results show that the HTG has good plugging performance in the steam channeling path and effectively controls its expanding. This forces the following steam, which is the steam injected after the gelling of HTG in the model, to flow through the steam unswept area, which improves the steam injection profile. During the gel profile control period, the cumulative oil production increases by 294.4 ml and the oil recovery is enhanced by 8.4%. Thus, this new HTG has a good effect in improving the steam injection profile and enhancing oil recovery and can be used to control the steam channeling in heavy oil reservoirs.
Effect of Solar Fraction on the Economic and Environmental Performance of Solar Air-Conditioning by Adsorption Chiller in a Tropical Region
Authors: Basrawi Firdaus , Ibrahim Thamir K. , Chui Lee Giok , Habib Khairul , Ibrahim Hassan
Published: October 2015

Solar air-conditioning (AC) is an attractive AC system but it has intermittent output, and therefore, a conventional heater is needed as a backup. This study presents the effect of ratio of heat delivered by solar (Qsolar) to the total heat delivered to an adsorption chiller (Qsolar + Qheater) or solar fraction (SF) on the economic and environmental performance of a solar AC. This solar AC is not a solar-assisted AC, and therefore, it needs to fully cover the cooling load. The cooling demand of an office building in Kuala Lumpur, and the performance of flat-plate collectors and the adsorption chiller were calculated by equest and watsun software and by a mathematical model, respectively. Economic performance was analyzed by life-cycle cost analysis, whereas the environmental performance was analyzed by using typical emissions rate of energy systems used. It was found that a boiler was a better solution than an electric heater as a backup heater. Furthermore, the net profit (NP) at lower SF was higher because of its lower capital investment, but more emissions were released compared to the conventional AC because of the boiler operation. Thus, when economic and environmental performance were fairly considered, it is appropriate to have solar AC with an SF around 0.74.
Flame Area Fluctuation Measurements in Velocity-Forced Premixed Gas Turbine Flames
Authors: De Rosa Alexander J. , Samarasinghe Janith , Peluso Stephen J. , Quay Bryan D. , Santavicca Domenic A.
Published: October 2015

Fluctuations in the heat release rate that occur during unstable combustion in lean-premixed gas turbine combustors can be attributed to velocity and equivalence ratio fluctuations. For a fully premixed flame, velocity fluctuations affect the heat release rate primarily by inducing changes in the flame area. In this paper, a technique to analyze changes in the flame area using chemiluminescence-based flame images is presented. The technique decomposes the flame area into separate components which characterize the relative contributions of area fluctuations in the large-scale structure and the small-scale wrinkling of the flame. The fluctuation in the wrinkled area of the flame which forms the flame brush is seen to dominate its response in the majority of cases tested. Analysis of the flame area associated with the large-scale structure of the flame resolves convective perturbations that move along the mean flame position. Results are presented that demonstrate the application of this technique to both single-nozzle and multi-nozzle flames.
The Instability Mechanism of a Confined Rod Under Axial Vibrations
Authors: Liu Jia , Su Tianxiang , Wicks Nathan , Pabon Jahir , Bertoldi Katia
Published: October 2015

We studied the stability of a confined rod under axial vibrations through a combination of analytical and numerical analysis. We find that the stability of the system is significantly different than in the static case and that both the frequency and magnitude of the applied vibrational force play an important role. In particular, while larger vibrational forces always tend to destabilize the system, our analysis indicates that the effect of the frequency is not obvious and monotonic. For certain frequencies, a very small force is sufficient to trigger an instability, while for others the rod is stable even for large forces. Furthermore, we find that the stability of the confined rod is significantly enhanced by the presence of frictional contact and that in this case also the magnitude of the perturbation affects its response.
Comparison Between Linear and Nonlinear Fracture Mechanics Analysis of Experimental Data for the Ductile Superalloy Haynes 230
Authors: Ewest Daniel , Almroth Per , Sjödin Björn , Leidermark Daniel , Simonsson Kjell
Published: October 2015

With increasing use of renewable energy sources, an industrial gas turbine is often a competitive solution to balance the power grid. However, life robustness approaches for gas turbine components operating under increasingly cyclic conditions are a challenging task. Ductile superalloys, as Haynes 230, are often used in stationary gas turbine hot parts such as combustors. The main load for such components is due to nonhomogeneous thermal expansion within or between parts. As the material is ductile, there is considerable redistribution of stresses and strains due to inelastic deformations during the crack initiation phase. Therefore, the subsequent crack growth occurs through a material with significant residual stresses and strains. In this work, fatigue crack propagation experiments, including the initiation phase, have been performed on a single edge notched specimen under strain controlled conditions. The test results are compared to fracture mechanics analyses using the linear ΔK and the nonlinear ΔJ approaches, and an attempt to quantify the difference in terms of a life prediction is made. For the tested notched geometry, material, and strain ranges, the difference in the results using ΔKeff or ΔJeff is larger than the scatter seen when fitting the model to the experimental data. The largest differences can be found for short crack lengths, when the cyclic plastic work is the largest. The ΔJ approach clearly shows better agreement with the experimental results in this regime.
Comparing Strategies for Topologic and Parametric Rule Application in Automated Computational Design Synthesis1
Authors: Königseder Corinna , Shea Kristina
Published: October 2015

Graph grammars are used for computational design synthesis (CDS) in which engineering knowledge is formalized using graphs to represent designs and rules that describe their transformation. Most engineering tasks require both topologic and parametric rules to generate designs. The research presented in this paper compares different strategies for rule application to combine topologic and parametric rules during automated design synthesis driven by a search process. The presented strategies are compared considering quantity and quality of the generated designs. The effect of the strategies, the selected search algorithm, and the initial design, from which the synthesis is started, are analyzed for two case studies: gearbox synthesis and bicycle frame synthesis. Results show that the effect of the strategy is dependent on the design task. Recommendations are given on which strategies to use for which design task.
Designing Rigidly Foldable Horns Using Bricard's Octahedron
Authors: Tachi Tomohiro
Published: October 2015

This paper proposes a design method to obtain a family of rigidly foldable structures with one degree-of-freedom (DOF). The mechanism of flat-foldable degree-four cones and mutually compatible cones sharing a boundary is interpreted as the mechanism of Bricard's flexible octahedra. By sequentially concatenating compatible cones, one can design horn-shaped rigid-origami mechanisms. This paper presents a method to inversely obtain rigidly foldable horns that follow given space curves. The resulting rigidly foldable horns can be used as building blocks for a transformable cellular structure and attachments to existing rigidly foldable structures.
Effect of Nozzle Junction and Equipment Stiffness on Absorption of Pipe Thermal Loads
Authors: Damle Kedar A. , Gharat Pratik S. , Neufeld Rudolf , Peters Wilhelm
Published: October 2015

As an industry norm, the nozzle local loads are considered to be local and are not considered in foundation design. Presently, this norm is under debate. One opinion is some percent of these loads are to be considered to be transferred to the foundation. The horizontal forces on the foundation are more critical than vertical forces. Attempt has been made to understand the system and create a model which will represent the system to a good approximation. A mathematical model is developed to demonstrate the actual system. It is a stiffness system consisting of equipment, nozzle junction, and connected piping. The connected pipes are heated sequentially to generate nozzle loads in axial and out plane directions. Steady-state thermal loads are calculated for the given system stiffness. Governing parameters are identified and altered to note the effect. The governing parameters identified are equipment diameter (D), nozzle location on equipment (x), and nozzle diameter (d). The effect is studied for pressure range (20–120 bar) and temperature (100–400 °C). The results of percentage loads transferred with respect to the governing parameters are plotted. It is observed that nozzle loads in axial directions are transferred to the foundation almost 100%, whereas out plane loads are absorbed by the system to a greater extent. Further study is required to investigate combined effects of all such nozzle loads for single equipment. The results may be refined for different materials and effect of nozzle reinforcement.
A Cell-Based Smoothed Radial Point Interpolation—Perfectly Matched Layer Method For Two-Dimensional Acoustic Radiation Problems
Authors: Yao Lingyun , Li Yunwu , Li Li
Published: October 2015

We present a cell-based smoothed radial point interpolation method (CS-RPIM) model for two-dimensional acoustic radiating problem by incorporating the perfectly matched layer method (PML). In this work, the computational region, truncated by PML, is discretized into triangular background cells. Each cell is further divided into several smoothing cells, and then the cell-based gradient smoothing operation is implemented throughout the smoothing cells. The pressure field function is approximated using the RPIM shape functions. The supporting node selection for shape function construction uses the T2L-scheme associated with edges of the background cells. The cell-based gradient smoothing operation provides proper softening effect, and makes the acoustic stiffness of the CS-RPIM model much softer than that of the FEM (finite element method)/PML model, which in turn significantly reduces the numerical dispersion error. Numerical results show that, compared with FEM–PML, the CS-RPIM achieves better absorbing effect in the PML, and higher accuracy in the computational region. This enables us to conclude that the CS-RPIM model with the PML can be well applied in solving acoustic radiation problems.
Recharacterization of Subsurface Flaw to Surface Flaw Based on Equivalent Fatigue Crack Growth Rate
Authors: Lacroix Valery , Li Yinsheng , Strnadel Bohumir , Hasegawa Kunio
Published: October 2015

A subsurface flaw located near a component surface is transformed to a surface flaw in accordance with a flaw-to-surface proximity rule. The recharacterization process from subsurface to surface flaw is adopted in all fitness-for-service (FFS) codes. However, the criteria of the recharacterizations are different among the FFS codes. In addition, the proximity factors in the rules are generally defined by constant values, irrespective of flaw aspect ratios. This paper describes the stress intensity factor interaction between the subsurface flaw and component free surface and proposes a proximity factor from the point of view of fatigue crack growth rates.
Catenary optics for achromatic generation of perfect optical angular momentum
Authors: Pu Mingbo , Li Xiong , Ma Xiaoliang , Wang Yanqin , Zhao Zeyu , Wang Changtao , Hu Chenggang , Gao Ping , Huang Cheng , Ren Haoran , Li Xiangping , Qin Fei , Yang Jing , Gu Min , Hong Minghui , Luo Xiangang
Published: October 2015

The nanoscale structures inspired by the natural catenaries can achromatically spin light wave.
A shortage of males causes female reproductive failure in yellow ground squirrels
Authors: Vasilieva Nina , Tchabovsky Andrey
Published: October 2015

Female yellow ground squirrels have fewer chances to breed when and where males are less abundant, independent of other factors.
Co-potentiation of antigen recognition: A mechanism to boost weak T cell responses and provide immunotherapy in vivo
Authors: Hoffmann Michele M. , Molina-Mendiola Carlos , Nelson Alfreda D. , Parks Christopher A. , Reyes Edwin E. , Hansen Michael J. , Rajagopalan Govindarajan , Pease Larry R. , Schrum Adam G. , Gil Diana
Published: October 2015

Fab binding to CD3 couples with weak antigen recognition to enhance T cell responses and immunotherapy.
Blue whales (
Balaenoptera musculus
) optimize foraging efficiency by balancing oxygen use and energy gain as a function of prey density
Authors: Hazen Elliott Lee , Friedlaender Ari Seth , Goldbogen Jeremy Arthur
Published: October 2015

The world’s largest predators, blue whales, switch strategies to maximize foraging efficiency as a function of prey density and depth.
Effects of ocean acidification on marine dissolved organic matter are not detectable over the succession of phytoplankton blooms
Authors: Zark Maren , Riebesell Ulf , Dittmar Thorsten
Published: October 2015

Simulations show that ocean acidification has little effect on marine dissolved organic matter concentration.
Pinning down the superfluid and measuring masses using pulsar glitches
Authors: Ho Wynn C. G. , Espinoza Cristóbal M. , Antonopoulou Danai , Andersson Nils
Published: October 2015

Erratic pulsar behavior hints at new way of measuring the mass of stars.
Microbiological Oxidation of Antimony(III) with Oxygen or Nitrate by Bacteria Isolated from Contaminated Mine Sediments
Authors: Terry Lee R. , Kulp Thomas R. , Wiatrowski Heather , Miller Laurence G. , Oremland Ronald S.
Published: October 2015

Bacterial oxidation of arsenite [As(III)] is a well-studied and important biogeochemical pathway that directly influences the mobility and toxicity of arsenic in the environment. In contrast, little is known about microbiological oxidation of the chemically similar anion antimonite [Sb(III)]. In this study, two bacterial strains, designated IDSBO-1 and IDSBO-4, which grow on tartrate compounds and oxidize Sb(III) using either oxygen or nitrate, respectively, as a terminal electron acceptor, were isolated from contaminated mine sediments. Both isolates belonged to the
Comamonadaceae
family and were 99% similar to previously described species. We identify these novel strains as
Hydrogenophaga
taeniospiralis
strain IDSBO-1 and
Variovorax paradoxus
strain IDSBO-4. Both strains possess a gene with homology to the
aioA
gene, which encodes an As(III)-oxidase, and both oxidize As(III) aerobically, but only IDSBO-4 oxidized Sb(III) in the presence of air, while strain IDSBO-1 could achieve this via nitrate respiration. Our results suggest that expression of
aioA
is not induced by Sb(III) but may be involved in Sb(III) oxidation along with an Sb(III)-specific pathway. Phylogenetic analysis of proteins encoded by the
aioA
genes revealed a close sequence similarity (90%) among the two isolates and other known As(III)-oxidizing bacteria, particularly
Acidovorax
sp. strain NO1. Both isolates were capable of chemolithoautotrophic growth using As(III) as a primary electron donor, and strain IDSBO-4 exhibited incorporation of radiolabeled [
14
C]bicarbonate while oxidizing Sb(III) from Sb(III)-tartrate, suggesting possible Sb(III)-dependent autotrophy. Enrichment cultures produced the Sb(V) oxide mineral mopungite and lesser amounts of Sb(III)-bearing senarmontite as precipitates.
Improvement of Glucose Uptake Rate and Production of Target Chemicals by Overexpressing Hexose Transporters and Transcriptional Activator Gcr1 in Saccharomyces cerevisiae
Authors: Kim Daehee , Song Ji-Yoon , Hahn Ji-Sook
Published: October 2015

Metabolic engineering to increase the glucose uptake rate might be beneficial to improve microbial production of various fuels and chemicals. In this study, we enhanced the glucose uptake rate in
Saccharomyces cerevisiae
by overexpressing hexose transporters (HXTs). Among the 5 tested HXTs (Hxt1, Hxt2, Hxt3, Hxt4, and Hxt7), overexpression of high-affinity transporter Hxt7 was the most effective in increasing the glucose uptake rate, followed by moderate-affinity transporters Hxt2 and Hxt4. Deletion of
STD1
and
MTH1
, encoding corepressors of
HXT
genes, exerted differential effects on the glucose uptake rate, depending on the culture conditions. In addition, improved cell growth and glucose uptake rates could be achieved by overexpression of
GCR1
, which led to increased transcription levels of
HXT1
and ribosomal protein genes. All genetic modifications enhancing the glucose uptake rate also increased the ethanol production rate in wild-type
S. cerevisiae
. Furthermore, the growth-promoting effect of
GCR1
overexpression was successfully applied to lactic acid production in an engineered lactic acid-producing strain, resulting in a significant improvement of productivity and titers of lactic acid production under acidic fermentation conditions.
Involutin Is an Fe
3+
Reductant Secreted by the Ectomycorrhizal Fungus Paxillus involutus during Fenton-Based Decomposition of Organic Matter
Authors: Shah Firoz , Schwenk Daniel , Nicolás César , Persson Per , Hoffmeister Dirk , Tunlid Anders
Published: October 2015

Ectomycorrhizal fungi play a key role in mobilizing nutrients embedded in recalcitrant organic matter complexes, thereby increasing nutrient accessibility to the host plant. Recent studies have shown that during the assimilation of nutrients, the ectomycorrhizal fungus
Paxillus involutus
decomposes organic matter using an oxidative mechanism involving Fenton chemistry (Fe
2+
+ H
2
O
2
+ H
+
→ Fe
3+
+ ˙OH + H
2
O), similar to that of brown rot wood-decaying fungi. In such fungi, secreted metabolites are one of the components that drive one-electron reductions of Fe
3+
and O
2
, generating Fenton chemistry reagents. Here we investigated whether such a mechanism is also implemented by
P. involutus
during organic matter decomposition. Activity-guided purification was performed to isolate the Fe
3+
-reducing principle secreted by
P. involutus
during growth on a maize compost extract. The Fe
3+
-reducing activity correlated with the presence of one compound. Mass spectrometry and nuclear magnetic resonance (NMR) identified this compound as the diarylcyclopentenone involutin. A major part of the involutin produced by
P. involutus
during organic matter decomposition was secreted into the medium, and the metabolite was not detected when the fungus was grown on a mineral nutrient medium. We also demonstrated that in the presence of H
2
O
2
, involutin has the capacity to drive an
in vitro
Fenton reaction via Fe
3+
reduction. Our results show that the mechanism for the reduction of Fe
3+
and the generation of hydroxyl radicals via Fenton chemistry by ectomycorrhizal fungi during organic matter decomposition is similar to that employed by the evolutionarily related brown rot saprotrophs during wood decay.
Two Pathways for Glutamate Biosynthesis in the Syntrophic Bacterium Syntrophus aciditrophicus
Authors: Kim Marie , Le Huynh M. , Xie Xiulan , Feng Xueyang , Tang Yinjie J. , Mouttaki Housna , McInerney Michael J. , Buckel Wolfgang
Published: October 2015

The anaerobic metabolism of crotonate, benzoate, and cyclohexane carboxylate bySyntrophus aciditrophicusgrown syntrophically withMethanospirillum hungateiprovides a model to study syntrophic cooperation. Recent studies revealed thatS. aciditrophicuscontainsRe-citrate synthase but lacks the commonSi-citrate synthase. To establish whether theRe-citrate synthase is involved in glutamate synthesis via the oxidative branch of the Krebs cycle, we have used [1-13C]acetate and [1-14C]acetate as well as [13C]bicarbonate as additional carbon sources during axenic growth ofS. aciditrophicuson crotonate. Our analyses showed that labeled carbons were detected in at least 14 amino acids, indicating the global utilization of acetate and bicarbonate. The labeling patterns of alanine and aspartate verified that pyruvate and oxaloacetate were synthesized by consecutive carboxylations of acetyl coenzyme A (acetyl-CoA). The isotopomer profile and13C nuclear magnetic resonance (NMR) spectroscopy of the obtained [13C]glutamate, as well as decarboxylation of [14C]glutamate, revealed that this amino acid was synthesized by two pathways. Unexpectedly, only the minor route usedRe-citrate synthase (30 to 40%), whereas the majority of glutamate was synthesized via the reductive carboxylation of succinate. This symmetrical intermediate could have been formed from two acetates via hydration of crotonyl-CoA to 4-hydroxybutyryl-CoA. 4-Hydroxybutyrate was detected in the medium ofS. aciditrophicuswhen grown on crotonate, but an active hydratase could not be measured in cell extracts, and the annotated 4-hydroxybutyryl-CoA dehydratase (SYN_02445) lacks key amino acids needed to catalyze the hydration of crotonyl-CoA. BesidesClostridium kluyveri, this study reveals the second example of a microbial species to employ two pathways for glutamate synthesis.
Facultative Control of Matrix Production Optimizes Competitive Fitness in Pseudomonas aeruginosa PA14 Biofilm Models
Authors: Madsen Jonas S. , Lin Yu-Cheng , Squyres Georgia R. , Price-Whelan Alexa , de Santiago Torio Ana , Song Angela , Cornell William C. , Sørensen Søren J. , Xavier Joao B. , Dietrich Lars E. P.
Published: October 2015

As biofilms grow, resident cells inevitably face the challenge of resource limitation. In the opportunistic pathogen
Pseudomonas aeruginosa
PA14, electron acceptor availability affects matrix production and, as a result, biofilm morphogenesis. The secreted matrix polysaccharide Pel is required for pellicle formation and for colony wrinkling, two activities that promote access to O
2
. We examined the exploitability and evolvability of Pel production at the air-liquid interface (during pellicle formation) and on solid surfaces (during colony formation). Although Pel contributes to the developmental response to electron acceptor limitation in both biofilm formation regimes, we found variation in the exploitability of its production and necessity for competitive fitness between the two systems. The wild type showed a competitive advantage against a non-Pel-producing mutant in pellicles but no advantage in colonies. Adaptation to the pellicle environment selected for mutants with a competitive advantage against the wild type in pellicles but also caused a severe disadvantage in colonies, even in wrinkled colony centers. Evolution in the colony center produced divergent phenotypes, while adaptation to the colony edge produced mutants with clear competitive advantages against the wild type in this O
2
-replete niche. In general, the structurally heterogeneous colony environment promoted more diversification than the more homogeneous pellicle. These results suggest that the role of Pel in community structure formation in response to electron acceptor limitation is unique to specific biofilm models and that the facultative control of Pel production is required for PA14 to maintain optimum benefit in different types of communities.
Landscape Position Influences Microbial Composition and Function via Redistribution of Soil Water across a Watershed
Authors: Du Zhe , Riveros-Iregui Diego A. , Jones Ryan T. , McDermott Timothy R. , Dore John E. , McGlynn Brian L. , Emanuel Ryan E. , Li Xu
Published: October 2015

Subalpine forest ecosystems influence global carbon cycling. However, little is known about the compositions of their soil microbial communities and how these may vary with soil environmental conditions. The goal of this study was to characterize the soil microbial communities in a subalpine forest watershed in central Montana (Stringer Creek Watershed within the Tenderfoot Creek Experimental Forest) and to investigate their relationships with environmental conditions and soil carbonaceous gases. As assessed by tagged Illumina sequencing of the 16S rRNA gene, community composition and structure differed significantly among three landscape positions: high upland zones (HUZ), low upland zones (LUZ), and riparian zones (RZ). Soil depth effects on phylogenetic diversity and β-diversity varied across landscape positions, being more evident in RZ than in HUZ. Mantel tests revealed significant correlations between microbial community assembly patterns and the soil environmental factors tested (water content, temperature, oxygen, and pH) and soil carbonaceous gases (carbon dioxide concentration and efflux and methane concentration). With one exception, methanogens were detected only in RZ soils. In contrast, methanotrophs were detected in all three landscape positions. Type I methanotrophs dominated RZ soils, while type II methanotrophs dominated LUZ and HUZ soils. The relative abundances of methanotroph populations correlated positively with soil water content (
R
= 0.72,
P
< 0.001) and negatively with soil oxygen (
R
= −0.53,
P
= 0.008). Our results suggest the coherence of soil microbial communities within and differences in communities between landscape positions in a subalpine forested watershed that reflect historical and contemporary environmental conditions.