bluuebunny/crossref_metadata_2025 huggingface dataset:
Weighted Average-Based Multi-Objective Optimization of Tube Spinning Process using Non-Traditional Optimization Techniques
Authors: Vundavilli Pandu R , Kumar J. Phani , Parappagoudar M.B.
Published: January 2014

Tube spinning is an effective process for producing long and thin walled tubes. It is important to note that the quality of parts produced in tube spinning process, namely internal surface roughness, external surface roughness, change in diameter and change in thickness depends on the right combination of input process parameters, such as mandrel rotational speed, feed rate of rollers, percentage of thickness reduction, initial thickness, solution treatment time and ageing treatment time. As the 2024 aluminum tube spinning process contains four objectives, it is very difficult to achieve a set of optimal combination of input process parameters that produce best quality product. This paper presents a weighted average-based multi-objective optimization of tube spinning process using non-traditional optimization techniques, namely genetic algorithm, particle swarm optimization and differential evolution. Multiple regression equations developed between the control factors and responses have been considered for optimization.
Airport Enterprise Service Bus with Three Levels Self-Healing Architecture (AESB-3LSH)
Authors: Afaneh Suha , Al Hadid Issam
Published: January 2014

This paper introduces the different aviation and airport information technology systems. Also, this paper provides Airport Enterprise Service Bus with Three Levels Self-Healing Architecture based on the Service Oriented Architecture (SOA) that improves the information accessibility and sharing across the different Airport’s departments, integrate the existing legacy systems with other applications, and improve and maximize the system’s reliability, adaptability, robustness and availability using the Self-Healing Agent, Virtual Web Service Self-Healing Connector and Extended Execution Engine with Process Execution Self-Healing Manager to guarantee the Quality of Service (QoS) or Service provided and business process execution.
Intentional Decentralization and Instinctive Centralization
Authors: Magnusson Johan
Published: January 2014

The aim of this study is to contribute to the body of knowledge surrounding centralization and decentralization of IT within the field of IT Governance. This is achieved through a revelatory case study of an ideographic organization, seen from the perspective of Social Transformation Processes. The study finds that the discussion in regards to whether IT should be centralized or decentralized is misdirected and needs to take additional aspects into account. As the case illustrates, organizations that hold dual identities encompass both organizational states simultaneously, whereby intentional decentralization is coupled with an instinctive centralization. The study illustrates limitations in the distinction between centralized and decentralized IT, as well as opens up for future studies of the organization of IT utilizing the perspective of social transformation processes.
The Impacts of Network Governance on the Performance of ITO
Authors: Chou Tzu-Chaun , Hsu Shu-Mei , Lee Gwo-Guang
Published: January 2014

Information technology outsourcing (ITO) has been a spotlight issue for global enterprises and previous studies have suggested that ITO research has expanded from one organization and bilateral partnerships to a global form of network organization. Yet, little research has been conducted on the link between network governance and ITO performance as a way to understand an organization’s ITO efforts. This study proposes a model that employs several constructs: inter-organizational coordination, contractual governance and relational governance, and technological hegemony. The model explores the mediating roles of these governance mechanisms and the moderating role of technological hegemony as it influences the IT manager’s perception of the performance of ITO. Empirical testing of the model is based on a sample of 191 companies from Taiwanese industries. The results support the mediating effect of relational governance and the moderating effect of technological hegemony. The model and results offer a perspective on managing the performance of ITO as well as initial insight into the role of technological hegemony.
Open Source Software Development Process Model
Authors: Siau Keng , Tian Yuhong
Published: January 2014

The global open source movement has provided software users with more choices, lower software acquisition cost, more flexible software customization, and possibly higher quality software product. Although the development of open source software is dynamic and it encourages innovations, the process can be chaotic and involve members around the globe. An Open Source Software Development (OSSD) process model to enhance the survivability of OSSD projects is needed. This research uses the grounded theory approach to derive a Phase-Role-Skill-Responsibility (PRSR) OSSD process model. The three OSSD process phases -- Launch Stage, Before the First Release, and Between Releases -- address the characteristics of the OSSD process as well as factors that influence the OSSD process. In the PRSR model, different roles/actors are required to have different skills and responsibilities corresponding to each of the three OSSD process phases. This qualitative research contributes to the software development literature as well as open source practice.
Gene Expression and Gene Ontology Enrichment Analysis for H3K4me3 and H3K4me1 in Mouse Liver and Mouse Embryonic Stem Cell Using ChIP-Seq and RNA-Seq
Authors: Tran Ngoc Tam L. , Huang Chun-Hsi
Published: January 2014

Recent study has identified the cis-regulatory elements in the mouse genome as well as their genomic localizations. Recent discoveries have shown the enrichment of H3 lysine 4 trimethylation (H3K4me3) binding as an active promoter and the presence of H3 lysine 4 monomethylation (H3K4me1) outside promoter regions as a mark for an enhancer. In this work, we further identified highly expressed genes by H3K4me3 mark or by both H3K4me3 and H3K4me1 marks in mouse liver using ChIP-Seq and RNA-Seq. We found that in mice, the liver carries embryonic stem cell-related functions while the embryonic stem cell also carries liver-related functions. We also identified novel genes in RNA-Seq experiments for mouse liver and for mouse embryonic stem cells. These genes are not currently in the Ensemble gene database at NCBI.
Efficacy of a Combined Treatment of Neem Oil Formulation and Endosulfan against Helicoverpa armigera (Hub.) (Lepidoptera: Noctuidae)
Authors: War Abdul Rashid , Paulraj Michael Gabriel , Hussain Barkat , Ahmad Tariq , War Mohd Yousf , Ignacimuthu Savarimuthu
Published: January 2014

Efficacy of the combined treatment of a neem oil formulation and endosulfan on feeding and midgut enzyme activities of Helicoverpa armigera larvae was studied. The antifeedant activity was recorded at 24 h after treatment and the activities of midgut digestive (total serine protease and trypsin) and detoxifying (esterase and glutathione-S-transferase) enzymes were estimated at 72 h after treatment. The antifeedant activity in endosulfan + neem oil formulation (endosulfan 0.01% and neem oil formulation 1% at 1:1 ratio) was 85.34%, significantly greater than in individual treatments. Midgut digestive enzymes and EST activities were significantly reduced and the GST activity significantly increased in the combined treatment of endosulfan + neem oil formulation, thus showing increased effect of the combined treatment of the two pesticides. These results suggest that neem oil can be used in combination with endosulfan to reduce its quantity.
Plasma amino acids, prolactin, insulin and glucose concentrations in lactating sows following venous infusion of isoleucine, leucine, lysine, threonine or valine
Authors: de Ridder K. A. G. , Farmer C. , de Lange C. F. M. , Shoveller A. K. , Luimes P. H.
Published: January 2014

de Ridder, K. A. G., Farmer, C., de Lange, C. F. M., Shoveller, A. K. and Luimes, P. H. 2014. Plasma amino acids, prolactin, insulin and glucose concentrations in lactating sows following venous infusion of isoleucine, leucine, lysine, threonine or valine. Can. J. Anim. Sci. 94: 323–330. The amino acid supply to lactating sows affects their milk yield, and the current study aims at establishing whether this is mediated via increases in concentrations of insulin and prolactin, two hormones that are important for lactation. Six multiparous Yorkshire sows (252.8±18.5 kg body weight) were fitted with an ear vein catheter and were used in a 6×6 Latin square design experiment from days 7 to 10 of lactation (am and pm infusions on 3 consecutive days). Sows were fed a commercial corn and soybean meal diet (17.1% crude protein) three times daily (1.5 kg at 0600 and 1200, 3.0 kg at 1830). Starting 2 h after the 0600 or 1200 feeding, sows received an infusion of saline (control), isoleucine, leucine, lysine, threonine or valine at a rate of 33 mL min−1during 30 min. The infused dose was equivalent to 18±0.9% of true ileal digestible intake for each of the amino acids. Serial blood samples were taken, starting 30 min prior to infusion and until 240 min after infusion. Plasma concentrations of amino acids, prolactin, insulin, and glucose were determined. Data were analyzed as repeated measurements and also using areas under the curve. Intravenous infusion with each of the five amino acids studied increased the corresponding free plasma amino acid concentrations (P<0.05). However, concentrations of prolactin, insulin, and glucose were not affected by infusion of any of the amino acids studied (P>0.10). Therefore, supplying intravenously 18% of the daily intake of isoleucine, leucine, lysine, threonine or valine brings about expected increases in amino acids, but does not alter the short-term response in prolactin, insulin or glucose concentrations of lactating sows.
Plant respiration in a high CO2 world: How will alternative oxidase respond to future atmospheric and climatic conditions?
Authors: Wang Jia , Cheung Melissa , Rasooli Lara , Amirsadeghi Sasan , Vanlerberghe Greg C.
Published: January 2014

Wang, J., Cheung, M., Rasooli, L., Amirsadeghi, S. and Vanlerberghe, G. C. 2014. Plant respiration in a high CO2 world: How will alternative oxidase respond to future atmospheric and climatic conditions? Can. J. Plant Sci. 94: 1091–1101. Plant mitochondria contain an alternative oxidase (AOX) that reduces the energy yield of respiration. While respiration and photosynthesis are known to interact, the role of AOX in the light remains poorly understood. This gap in our understanding of leaf metabolism extends to future conditions of high CO2 and climate change. While studies indicate that AOX respiration is quite responsive to growth conditions, few studies have examined AOX respiration at high CO2 and little is known regarding the combined impact of changes in both CO2 and other climatic factors such as temperature and water availability. Given its non-energy conserving nature, a fundamental response by AOX to these future conditions could impact the net carbon gain that results from the combined processes of photosynthesis and respiration. Here, we show that leaf AOX protein amount in Nicotiana tabacum is dependent upon growth irradiance and CO2 level, that AOX is subject to biochemical control by intermediates of photorespiration, and that photosynthesis is impacted in transgenic plants lacking AOX. We also review findings that tobacco AOX respiration is responsive to climatic variables (temperature, water availability), thus providing an excellent experimental system to investigate the interplay between AOX, photosynthesis at high CO2, and climate change.
An empirical model for changes in the leaf area of maize
Authors: Chen Guoqing , Zhang Jiwang , Liu Peng , Dong Shuting
Published: January 2014

Chen, G., Zhang, J., Liu, P. and Dong, S. 2014. An empirical model for changes in the leaf area of maize. Can. J. Plant Sci. 94: 749–757. Accurate predictions of the leaf area index (LAI) are critical for many crop growth simulation models and essential for simulating crop growth and yield. In this paper, we present a new empirical leaf area model that simulates LAI for different maize (Zea mays L.) varieties under different cultivation conditions. Based on leaf morphological development, the model describes the two processes of leaf growth: expansion and senescence. The effect of planting density and nitrogen on LAI was also simulated in the model. A nitrogen sensitivity parameter was used to distinguish the different varieties. The model predictions were compared with field measurements of LAI for four varieties under different conditions. The results showed that the new model can correctly simulate LAI for maize under different cultivation conditions. The sensitivity analyses revealed that the new LAI model was very sensitive to lle (the length of the ear leaf) and VN (fertilizer sensitivity parameters of cultivars). The new model facilitates the simulation of maize leaf growth and senescence at the population level.
Biological activity of entomopathogenic actinomycetes against lepidopteran insects (Noctuidae: Lepidoptera)
Authors: Vijayabharathi Rajendran , Kumari Bhimineni Ratna , Sathya Arumugam , Srinivas Vadlamudi , Abhishek Rathore , Sharma Hari C. , Gopalakrishnan Subramaniam
Published: January 2014

Vijayabharathi, R., Kumari, B. R., Sathya, A., Srinivas, V., Abhishek, R., Sharma, H. C. and Gopalakrishnan, S. 2014. Biological activity of entomopathogenic actinomycetes against lepidopteran insects (Noctuidae: Lepidoptera). Can. J. Plant Sci. 94: 759–769. The aim of the present study was to identify an efficient broad-spectrum bio-pesticide for the control of lepidopteran insects from microbes in various ecological niches. A total of 111 microbes isolated from various herbal vermi-composts and organically cultivated fields were evaluated for their intracellular metabolites (ICM), extracellular metabolites (ECM) and whole culture (WC) against early instars of lepidopteran insects. Fifteen actinomycete isolates which showed insecticidal activity against 2nd instar Helicoverpa armigera were selected and further screened against Spodoptera litura and Chilo partellus. A significant broad spectrum insecticidal activity was found in the order ECM>ICM>WC against all the insects under laboratory conditions. All these actinomycete isolates also registered significant activity under greenhouse conditions on 2nd instar H. armigera. The actinomycete isolates were identified by 16S rDNA sequencing and matched with Streptomyces species using BLAST search. Among all the 15 isolates, SAI-25 (S. griseoplanus), CAI-155 (S. bacillaris) and BCA-698 (S. albolongus) showed consistent entomopathogenic activity against all the three insects suggesting their potential as broad-spectrum biocontrol agents against other lepidopterans.
On-farm seed loss does not differ between windrowed and direct-harvested canola
Authors: Haile Teketel A. , Gulden Robert H. , Shirtliffe Steven J.
Published: January 2014

Haile, T. A., Gulden, R. H. and Shirtliffe, S. J. 2014. On-farm seed loss does not differ between windrowed and direct-harvested canola. Can. J. Plant Sci. 94: 785–789. Seed loss in canola (Brassica napus) leads to considerable loss of revenue and dispersal of seeds into the soil seedbank. The resulting volunteer canola can create weed problems in subsequent crops and result in further yield loss. The objective of this study was to quantify and compare canola seed loss and seedbank addition from windrowing and direct-harvesting operations on commercial farms in western Canada. A total of 16 direct-harvested and 19 windrowed canola fields were surveyed in central and southern Saskatchewan during 2010, 2011 and 2012. Shattered seeds from these fields were sampled within 3 wk after harvest of the crop using a vacuum cleaner. There were no differences in seed yield, loss or seedbank addition of canola between windrowing and direct-harvesting operations. There was a difference in 1000-seed weight between the harvest methods and seeds of the direct-harvested canola were larger in size. This may suggest that direct-harvesting can be considered as a viable option to harvest canola in western Canada.
Water use efficiency of spring wheat in the semi-arid Canadian prairies: Effect of legume green manure, type of spring wheat, and cropping frequency
Authors: Kröbel R. , Lemke R. , Campbell C. A. , Zentner R. , McConkey B. , Steppuhn H. , De Jong R. , Wang H.
Published: January 2014

Kröbel, R., Lemke, R., Campbell, C. A., Zentner, R., McConkey, B., Steppuhn, H., De Jong, R. and Wang, H. 2014. Water use efficiency of spring wheat in the semi-arid Canadian prairies: Effect of legume green manure, type of spring wheat, and cropping frequency. Can. J. Soil Sci. 94: 223–235. In the semi-arid Canadian prairie, water is the main determinant of crop production; thus its efficient use is of major agronomic interest. Previous research in this region has demonstrated that the most meaningful way to measure water use efficiency (WUE) is to use either precipitation use efficiency (PUE) or a modified WUE that accounts for the inefficient use of water in cropping systems that include summer fallow. In this paper, we use these efficiency measures to determine how cropping frequency, inclusion of a legume green manure, and the type of spring wheat [high-yielding Canada Prairie Spring (CPS) vs. Canada Western Red Spring (CWRS)] influence WUE using 25 yr of data (1987–2011) from the “New Rotation” experiment conducted at Swift Current, Saskatchewan. This is a well-fertilized study that uses minimum and no-tillage techniques and snow management to enhance soil water capture. We compare these results to those from a 39-yr “Old Rotation” experiment, also at Swift Current, which uses conventional tillage management. Our results confirmed the positive effect on WUE of cropping intensity, and of CPS wheat compared with CWRS wheat, while demonstrating the negative effect on WUE of a green manure crop in wheat-based rotations in semiarid conditions. Furthermore, we identified a likely advantage of using reduced tillage coupled with water conserving snow management techniques for enhancing the efficiency of water use.
Strong Asymptotic Freeness for Free Orthogonal Quantum Groups
Authors: Brannan Michael
Published: January 2014

It is known that the normalized standard generators of the free orthogonal quantum groupO+Nconverge in distribution to a free semicircular system as N → ∞. In this note, we substantially improve this convergence result by proving that, in addition to distributional convergence, the operator normof any non-commutative polynomial in the normalized standard generators ofO+Nconverges asN→ ∞ to the operator norm of the corresponding non-commutative polynomial in a standard free semicircular system. Analogous strong convergence results are obtained for the generators of free unitary quantum groups. As applications of these results, we obtain a matrix-coefficient version of our strong convergence theorem, and we recover a well-knownL2-L∞norm equivalence for noncommutative polynomials in free semicircular systems.
The Rasmussen Invariant, Four-genus, and Three-genus of an Almost Positive Knot Are Equal
Authors: Tagami Keiji
Published: January 2014

An oriented link is positive if it has a link diagram whose crossings are all positive. An oriented link is almost positive if it is not positive and has a link diagram with exactly one negative crossing. It is known that the Rasmussen invariant, 4-genus, and 3-genus of a positive knot are equal. In this paper, we prove that the Rasmussen invariant, 4-genus, and 3-genus of an almost positive knot are equal. Moreover, we determine the Rasmussen invariant of an almost positive knot in terms of its almost positive knot diagram. As corollaries, we prove that all almost positive knots are not homogeneous, and there is no almost positive knot of 4-genus one.
Logistics of Guinea Worm Disease Eradication in South Sudan
Authors: Jones Alexander H. , Becknell Steven , Withers P. Craig , Ruiz-Tiben Ernesto , Hopkins Donald R. , Stobbelaar David , Makoy Samuel Yibi
Published: January 2014

From 2006 to 2012, the South Sudan Guinea Worm Eradication Program reduced new Guinea worm disease (dracunculiasis) cases by over 90%, despite substantial programmatic challenges. Program logistics have played a key role in program achievements to date. The program uses disease surveillance and program performance data and integrated technical–logistical staffing to maintain flexible and effective logistical support for active community-based surveillance and intervention delivery in thousands of remote communities. Lessons learned from logistical design and management can resonate across similar complex surveillance and public health intervention delivery programs, such as mass drug administration for the control of neglected tropical diseases and other disease eradication programs. Logistical challenges in various public health scenarios and the pivotal contribution of logistics to Guinea worm case reductions in South Sudan underscore the need for additional inquiry into the role of logistics in public health programming in low-income countries.
The efficiency and spectral photon dose dependence of photochemically induced changes to the bioavailability of dissolved organic carbon
Authors: Reader Heather E. , Miller William L.
Published: January 2014

To quantify the effects of photochemistry on the biological lability of dissolved organic carbon in a terrestrially influenced system, a quarterly sampling effort was undertaken at three estuarine locations along the coast of Georgia, producing a total of 15 apparent quantum yield (AQY) spectra for biologically labile products (BLPs). Prefiltered samples were irradiated and then inoculated with natural microbial communities isolated from the same sample. Oxygen consumption was used as a proxy for community carbon utilization over 10–12 d dark incubations. Seasonal microbial response to irradiated samples ranged from ‒21% to +155% relative to dark controls. AQY spectral shapes were not consistent over the data set, nor were there any apparent patterns in season or location. Progressive photon dose experiments showed that increasing irradiation length strongly decreased the total biolabile product as assayed with microbial community oxygen consumption, as well as altering the spectral shape of the AQY spectra. A conceptual model is presented to explain this dependence on photon dose, by illustrating the competition between the photochemical production and photochemical destruction of BLPs. The varying dependence on photon dose is fundamentally different from published results for other photochemical products and further complicates attempts to quantify the total effect of photochemistry on organic carbon cycles in natural environments.
Consequences of UV‐enhanced community respiration for plankton metabolic balance
Authors: Agustí Susana , Regaudie-de-Gioux Aurore , Arrieta Jesús M. , Duarte Carlos M.
Published: January 2014

The net community production (NCP) of plankton communities affects their role as sources or sinks of atmospheric CO2. Most estimates of NCP have been made by enclosing communities in bottles, generally glass borosilicate, that remove ultraviolet (UV)B and part of UVA wavelengths. A series of experiments were conducted to test whether NCP values from communities incubated excluding UVB (+ part of UVA) radiation (i.e., in glass borosilicate) differ from those of communities receiving the full solar radiation spectrum (i.e., incubated with quartz bottles) and to explore the effect of UV radiation on the respiration rates and bacterial production in these communities. Plankton NCP tended to be 43% lower, on average, when the rates were measured under full solar radiation than when UVB (+ part of UVA) was removed. Dark respiration was significantly enhanced after exposure to the full solar spectrum for most communities, showing lower values when previously incubated in a light environment free of UVB (‒50%) or in the dark (‒62%). Bacterial production was inhibited by natural sunlight but increased, as observed for community respiration, when transferred to the dark. Communities previously exposed to full solar spectrum showed the greatest increase in bacterial production when allowed to recover in the dark. The net result of these responses were an increase in community respiration and decline in net community production over 24 h, indicating that UVB radiation plays a major role in the metabolic balance of the ocean's surface ecosystem.
Improved parameterization of seagrass blade dynamics and wave attenuation based on numerical and laboratory experiments
Authors: Zeller Robert B. , Weitzman Joel S. , Abbett Morgan E. , Zarama Francisco J. , Fringer Oliver B. , Koseff Jeffrey R.
Published: January 2014

Seagrass blade dynamics were explored through numerical and laboratory experiments in order to improve parameterization of wave attenuation by submerged aquatic vegetation in the presence of a background current. In the numerical model, a single blade was modeled as a series of rigid plates attached by torsion springs. For the laboratory model, strips of low‐density polyethylene were placed in a recirculating wave flume. A new form of the Keulegan—Carpenter number based on the horizontal excursion of the blade tip was found to be an excellent predictor of drag coefficient. An algebraic model for predicting wave attenuation was developed based on the following observations. During the portion of the wave period when the fluid velocities are highest, the blade motion is almost completely arrested and the vast majority of the turbulence production occurs during this time. Turbulence production when the blade is pronated is accurately predicted by the maximum fluid velocity over the wave period. The relative contribution to the total turbulence production over the wave period is determined by the relative strength of the waves and the current. Therefore, using a simple algebraic fit, the total depth‐integrated, time‐averaged turbulence production can be accurately predicted by two flow parameters: the maximum fluid velocity over the wave period, and a non‐dimensional number that compares the wave and current velocities. By fitting the algebraic model to data from a particular site, it can be used to efficiently estimate wave attenuation and drag coefficient in seagrass exposed to waves with a background current.
Anthropogenic nutrient sources rival natural sources on small scales in the coastal waters of the Southern California Bight
Authors: Howard Meredith D. A. , Sutula Martha , Caron David A. , Chao Yi , Farrara John D. , Frenzel Hartmut , Jones Burton , Robertson George , McLaughlin Karen , Sengupta Ashmita
Published: January 2014

Anthropogenic nutrients have been shown to provide significant sources of nitrogen (N) that have been linked to increased primary production and harmful algal blooms worldwide. There is a general perception that in upwelling regions, the flux of anthropogenic nutrient inputs is small relative to upwelling flux, and therefore anthropogenic inputs have relatively little effect on the productivity of coastal waters. To test the hypothesis that natural sources (e.g., upwelling) greatly exceed anthropogenic nutrient sources to the Southern California Bight (SCB), this study compared the source contributions of N from four major nutrient sources: (1) upwelling, (2) treated wastewater effluent discharged to ocean outfalls, (3) riverine runoff, and (4) atmospheric deposition. This comparison was made using large regional data sets combined with modeling on both regional and local scales. At the regional bight‐wide spatial scale, upwelling was the largest source of N by an order of magnitude to effluent and two orders of magnitude to riverine runoff. However, at smaller spatial scales, more relevant to algal bloom development, natural and anthropogenic contributions were equivalent. In particular, wastewater effluent and upwelling contributed the same quantity of N in several subregions of the SCB. These findings contradict the currently held perception that in upwelling‐dominated regions anthropogenic nutrient inputs are negligible, and suggest that anthropogenic nutrients, mainly wastewater effluent, can provide a significant source of nitrogen for nearshore productivity in Southern California coastal waters.
Micro‐aerobic bacterial methane oxidation in the chemocline and anoxic water column of deep south‐Alpine Lake Lugano (Switzerland)
Authors: Blees Jan , Niemann Helge , Wenk Christine B. , Zopfi Jakob , Schubert Carsten J. , Kirf Mathias K. , Veronesi Mauro L. , Hitz Carmen , Lehmann Moritz F.
Published: January 2014

We measured seasonal variations in the vertical distribution of methane concentration, methane oxidation rates, and lipid biomarkers in the northern basin of Lake Lugano. Methane consumption below the oxic—anoxic interface co‐occurred with concentration maxima of 13C‐depleted C16 fatty acid biomarkers (with δ13C values as low as −70‰) in the anoxic water column, as well as characteristic δ13CCH4 profiles. We argue that the conspicuous methane concentration gradients are primarily driven by (micro‐)aerobic methane oxidation (MOx) below the chemocline. We measured a strong MOx potential throughout the anoxic water column, while MOx rates at in situ O2 concentration > 10 nmol L−1 were undetectable. Similarly, we found MOx‐related biomarkers and gene sequences encoding the particulate methane monooxygenase in the anoxic, but not the oxic, water. The mechanism of (episodic) oxygen supply sustaining the MOx community in anoxic waters is still uncertain. Our results indicate that a bacterial methanotrophic community is responsible for the methane consumption in Lake Lugano, without detectable contribution from archaeal methanotrophs. Bacterial populations that accumulated both at the suboxic—anoxic interface and in the deeper anoxic hypolimnion, where maximum potential MOx rates were observed throughout the year (1.5–2.5 µmol L−1 d−1) were mainly related to Methylobacter sp. Close relatives are found in lacustrine environments throughout the world, and their potential to thrive under micro‐ and anoxic conditions in Lake Lugano may imply that micro‐aerobic methane oxidation is important in methane cycling and competition for methane and oxygen in stratified lakes worldwide.
Long‐term study of minerogenic particle optics in Cayuga Lake, New York
Authors: Effler Steven W. , Peng Feng
Published: January 2014

The dynamics of light scattering by minerogenic particles in the upper waters of Cayuga Lake, New York, were characterized for the spring—autumn interval of 8 yr (1999–2006) at pelagic and nearshore sites with a scanning electron microscope interfaced with automated image and x‐ray analyses (SAX). SAX results were used to estimate the minerogenic scattering coefficient (bm) through Mie theory calculations. SAX—Mie supported a two‐component model for particulate scattering (bp) that included an organic component of scattering (bo), estimated from a bio‐optical model. The credibility of the bm estimates and the two‐component modeling approach was demonstrated through good closure of the modeling results with bulk values of bp (estimated from measurements of the beam attenuation coefficient at 660 nm). The average of the ratio bp : (bm + bo) was 1.03 (average relative error 19.4%). Two minerogenic particle types were important in regulating the dynamics of bm—clay minerals that increased in concentration in response to runoff events, and calcium carbonate precipitated mostly on small organic particles during short‐term late‐summer whiting events. bm was attributed to particles in the size range of 1–10 µm. Variations in bm dominated the overall variations in bp and Secchi disk depth; differences in bo explained well those observed in bp during dry weather intervals of low bm. Higher bm values, mainly associated with clay mineral particles, were observed at the nearshore site as opposed to the pelagic location; there was a positive linkage between these levels and tributary flow rate.
Habitat structure and ecological drivers of disease
Authors: Penczykowski Rachel M. , Hall Spencer R. , Civitello David J. , Duffy Meghan A.
Published: January 2014

Habitat can influence disease directly, through effects on hosts and parasites, or indirectly, through effects on ecological drivers of disease. We illustrated direct and indirect connections between habitat and outbreaks using a case study in the plankton. We sampled yeast epidemics in 18 populations of the lake zooplankter Daphnia dentifera. Lake size drove variation in two types of habitat structure, size of predation refuges and strength of stratification. Those habitat factors, in turn, indirectly linked to epidemics through two pathways involving nonhost species. In the first pathway, larger lakes had larger hypolimnetic refuges from vertebrate predation and greater densities of Daphnia pulicaria, a completely resistant species that can reduce disease risk for D. dentifera hosts by removing parasite spores from the environment. In lakes with more D. pulicaria, epidemics started later in autumn and remained smaller. In the second pathway, smaller lakes had shallower penetration of light, which correlated with stronger thermal stratification and higher densities of an invertebrate predator (Chaoborus) that spreads disease by releasing spores from infected hosts. Lakes with weaker stratification had fewer of these predators and smaller epidemics. In the second pathway, deeper light penetration may also decrease disease by imposing direct mortality on spores. Thus, this case study shows how habitat structure could influence epidemics through direct and indirect effects on the host—parasite system. Understanding these multiple mechanisms can enhance prediction of disease outbreaks as habitat modification continues in lakes and other ecosystems worldwide.
Effects of iron limitation on growth and carbon metabolism in oceanic and coastal heterotrophic bacteria
Authors: Fourquez Marion , Devez Aurélie , Schaumann Annick , Guéneuguès Audrey , Jouenne Thierry , Obernosterer Ingrid , Blain Stéphane
Published: January 2014

We investigated the metabolic response to iron (Fe) limitation of two bacterial strains of Alteromonas macleodii, isolated from a coastal and an oceanic marine environment. Bacteria were grown under Fe‐limited and Fe‐replete conditions, and comparative analyses of cellular properties and total proteomes were conducted. Respiration was reduced by a factor of two in both strains, but the growth rate of the oceanic strain was less affected by Fe limitation (reduced by 1.2‐fold) than the coastal strain (reduced by 2‐fold). Fe limitation led to significant changes in the expression of several key enzymes associated with carbon catabolism, specifically those involved in the citric acid cycle, glycolysis, and oxidative phosphorylation. The strain‐specific overall responses to Fe limitation were in part reflected in different metabolic strategies of the carbon metabolism and energy acquisition. Our study provides novel insights on how Fe limitation can affect bacterial heterotrophic metabolism, and how this could influence the coupling of the Fe and carbon cycles in the ocean.
Interpretation of freezing nucleation experiments: singular and stochastic; sites and surfaces
Authors: Vali G.
Published: January 2014

Abstract. Publications of recent years dealing with laboratory experiments of immersion freezing reveal uncertainties about the fundamentals of heterogeneous freezing nucleation. While it appears well accepted that there are two major factors that determine the process, namely fluctuations in the size and configuration of incipient embryos of the solid phase and the role of the substrate to aid embryo formation, views have been evolving about the relative importance of these two elements. The importance of specific surface sites is being established in a growing number of experiments and a number of approaches have been proposed to incorporate these results into model descriptions. Many of these models share a common conceptual basis yet diverge in the way random and deterministic factors are combined. The divergence can be traced to uncertainty about the permanence of nucleating sites, to the lack of detailed knowledge about what surface features constitute nucleating sites, and to the consequent need to rely on empirical or parametric formulas to define the population of sites of different effectiveness. The goal of this paper is to demonstrate that recent experiments and models, consistent with earlier work, point to the existence and primary role of permanent nucleating sites and to the continued need for empirically based formulations of heterogeneous freezing. The paper focuses on three identifiably separate but interrelated issues: (i) the combination of singular and stochastic factors, (ii) the role of specific surface sites, and (iii) the modeling of heterogeneous ice nucleation.
Simultaneous parameterization of the two-source evapotranspiration model by Bayesian approach: application to spring maize in an arid region of northwest China
Authors: Zhu G. F. , Li X. , Su Y. H. , Zhang K. , Bai Y. , Ma J. Z. , Li C. B. , Hu X. L. , He J. H.
Published: January 2014

Abstract. Based on direct measurements of half-hourly canopy evapotranspiration (ET; W m−2) using the eddy covariance (EC) system and daily soil evaporation (E; mm d−1) using microlysimeters over a crop ecosystem in arid northwest China from 27 May to 14 September in 2013, a Bayesian method was used to simultaneously parameterize the soil surface and canopy resistances in the Shuttleworth–Wallace (S–W) model. The posterior distributions of the parameters in most cases were well updated by the multiple measuring dataset with relatively narrow high-probability intervals. There was a good agreement between measured and simulated values of half-hourly ET and daily E with a linear regression being y = 0.84x +0.18 (R2 = 0.83) and y = 1.01x + 0.01 (R2 = 0.82), respectively. The causes of underestimations of ET by the S–W model was mainly attributed to the micro-scale advection, which can contribute an added energy in the form of downward sensible heat fluxes to the ET process. Therefore, the advection process should be taken into accounted in simulating ET in heterogeneous land surface. Also, underestimations were observed on or shortly after rainy days due to direct evaporation of liquid water intercepted in the canopy. Thus, the canopy interception model should be coupled to the S–W model in the long-term ET simulation.
A dual-inexact fuzzy stochastic model for water resources management and non-point source pollution mitigation under multiple uncertainties
Authors: Dong C. , Tan Q. , Huang G.-H. , Cai Y.-P.
Published: January 2014

Abstract. In this research, a dual-inexact fuzzy stochastic programming (DIFSP) method was developed for supporting the planning of water and farmland use management system considering the non-point source pollution mitigation under uncertainty. The random boundary interval (RBI) was incorporated into DIFSP through integrating fuzzy programming (FP) and chance-constrained programming (CCP) approaches within an interval linear programming (ILP) framework. The lower and upper bounds of RBI are continuous random variables, and the correlation exiting between the lower and upper bounds can be tackled in RBI through the joint probability distribution function. And thus the subjectivity of decision making is greatly reduced, enhancing the stability and robustness of obtained solutions. The proposed method was then applied to solve a water and farmland use planning model (WFUPM) with non-point source pollution. The generated results could provide decision makers with detailed water supply-demand schemes involving diversified water related activities under various system conditions. These useful solutions could allow more in-depth analyses of the trade-offs between human and environment, as well as those between system optimality and reliability. In addition, comparative analyses on the solutions obtained from ICCP (Interval chance-constraints programming) and DIFSP demonstrated the higher application of this developed approach for supporting the water and farmland use system planning.
The role of different factors related to social impact of heavy rain events: considerations about the intensity thresholds in densely populated areas
Authors: Barbería L. , Amaro J. , Aran M. , Llasat M. C.
Published: January 2014

Abstract. In the assessment of social impact caused by meteorological events, factors of different nature need to be considered. Not only does hazard itself determine the impact that a severe weather event has on society, but also other features related to vulnerability and exposure. The requests of data related to insurance claims received in Meteorological Services proved to be a good indicator of the social impact that a weather event causes, according to studies carried out by the Social Impact Research Group, created under the frame of the MEDEX project. Taking these requests as proxy data, diverse aspects connected to the impact of heavy rain events have been studied. The rainfall intensity in conjunction with the population density has demonstrated to be one of the key factors in social impact studies. One of the conclusions we obtained is that various thresholds of rainfall should be applied for differently populated areas. In this study, the role of rainfall intensity has been analysed for a highly populated urban area like Barcelona. A period without significant population changes has been selected for the study to minimise the effects linked to vulnerability and exposure. First, correlations between rainfall recorded in different time intervals and requests have been carried out. Afterwards, a method to include the intensity factor in the social impact index has been suggested, based on return periods given by Intensity-Duration-Frequency (IDF) curves.
Avalanche situation in Turkey and back-calculation of selected events
Authors: Aydın A. , Bühler Y. , Christen M. , Gürer I.
Published: January 2014

Abstract. In Turkey, an average of 24 people dies in snow avalanches every year, mainly in the eastern part of Anatolia and in the eastern Black Sea Region where high mountain ranges are close to the sea. The proportion of people killed in buildings is very high (87%), especially in comparison to other European and American countries. In this paper we discuss avalanche occurrence, the climatic situation and historical avalanche events in Turkey; in addition, we identify bottlenecks and suggest solutions to tackle avalanche problems. Furthermore, we have applied the numerical avalanche simulation software RAMMS combined with a Digital Elevation Model (DEM)-based potential release zone identification algorithm to analyze the catastrophic avalanche events in the villages of Üzengili (Bayburt province) in 1993 and Yaylaönü (Trabzon province) in 1981. The results demonstrate the value of such an approach for regions with poor avalanche databases, enabling the calculation of different scenarios and the estimation of run-out distances, flow velocities, impact pressure and flow height.
The comparative study of chaoticity and dynamical complexity of the low-latitude ionosphere, over Nigeria, during quiet and disturbed days
Authors: Ogunsua B. O. , Laoye J. A. , Fuwape I. A. , Rabiu A. B.
Published: January 2014

Abstract. The deterministic chaotic behavior and dynamical complexity of the space plasma dynamical system over Nigeria are analyzed in this study and characterized. The study was carried out using GPS (Global Positioning System) TEC (Total Electron Content) time series, measured in the year 2011 at three GPS receiver stations within Nigeria, which lies within the equatorial ionization anomaly region. The TEC time series for the five quietest and five most disturbed days of each month of the year were selected for the study. The nonlinear aspect of the TEC time series was obtained by detrending the data. The detrended TEC time series were subjected to various analyses for phase space reconstruction and to obtain the values of chaotic quantifiers like Lyapunov exponents, correlation dimension and also Tsallis entropy for the measurement of dynamical complexity. The observations made show positive Lyapunov exponents (LE) for both quiet and disturbed days, which indicates chaoticity, and for different days the chaoticity of the ionosphere exhibits no definite pattern for either quiet or disturbed days. However, values of LE were lower for the storm period compared with its nearest relative quiet periods for all the stations. The monthly averages of LE and entropy also show no definite pattern for the month of the year. The values of the correlation dimension computed range from 2.8 to 3.5, with the lowest values recorded at the storm period of October 2011. The surrogate data test shows a significance of difference greater than 2 for all the quantifiers. The entropy values remain relatively close, with slight changes in these values during storm periods. The values of Tsallis entropy show similar variation patterns to those of Lyapunov exponents, with a lot of agreement in their comparison, with all computed values of Lyapunov exponents correlating with values of Tsallis entropy within the range of 0.79 to 0.81. These results show that both quantifiers can be used together as indices in the study of the variation of the dynamical complexity of the ionosphere. The results also show a strong play between determinism and stochasticity. The behavior of the ionosphere during these storm and quiet periods for the seasons of the year are discussed based on the results obtained from the chaotic quantifiers.
Residual circulation and fresh-water transport in the Dutch Wadden Sea: a numerical modeling study
Authors: Duran-Matute M. , Gerkema T. , de Boer G. J. , Nauw J. J. , Gräwe U.
Published: January 2014

Abstract. The Dutch Wadden Sea is a region of intertidal flats located between the chain of Wadden Islands and the Dutch mainland. We present numerical model results on the tidal prisms and residual flows through the tidal inlets and across one of the main watersheds. The model also provides insight into the pathways of fresh water originating from the two sluices at the Afsluitdijk (enclosure dike) through the use of passive tracers. All these results are obtained from three-dimensional numerical simulations carried out with the General Estuarine Transport Model (GETM), at a horizontal resolution of 200 m and with terrain-following vertical coordinates with 30 layers. We concentrate on the years 2009–2010, for which we impose meterological forcing, fresh-water discharge, and boundary conditions for tidal forcing and storm surges. Results from the model show an excellent agreement with various observational data sets for sea surface height, temperature, salinity, and transport through the Texel Inlet. The simulations show that although tides are responsible for a characteristic pattern of residual transport through the inlets, the wind imposes a large variability on its magnitude and can even invert its direction during strong southwesterly winds. Even though these events are sporadic, they play an important role in the flushing of the Dutch Wadden Sea, as they strongly diminish the flushing time of fresh water. In addition, wind can force a residual transport across the Terschelling watershed of the same order, if not larger, than through any of the main tidal inlets, despite the fact that the tidal prism associated with the watershed is much smaller than any of those of the inlets. For the pathways of fresh water, the same watershed turns out to be more important than was previously thought, while the opposite holds for the Vlie Inlet.