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Challenges, Volume 5, Issue 1 (June 2014), Pages 1-192

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Editorial

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Open AccessEditorial Acknowledgement to Reviewers of Challenges in 2013
Challenges 2014, 5(1), 98-99; doi:10.3390/challe5010098
Received: 26 February 2014 / Accepted: 26 February 2014 / Published: 26 February 2014
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Abstract The editors of Challenges would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2013. [...] Full article

Research

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Open AccessArticle How China’s Options Will Determine Global Warming
Challenges 2014, 5(1), 1-25; doi:10.3390/challe5010001
Received: 25 October 2013 / Revised: 12 December 2013 / Accepted: 13 December 2013 / Published: 30 December 2013
Cited by 1 | PDF Full-text (5045 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Carbon dioxide emissions, global average temperature, atmospheric CO2 concentrations, and surface ocean mixed layer acidity are extrapolated using analyses calibrated against extensive time series data for nine global regions. Extrapolation of historical trends without policy-driven limitations has China responsible for about half of
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Carbon dioxide emissions, global average temperature, atmospheric CO2 concentrations, and surface ocean mixed layer acidity are extrapolated using analyses calibrated against extensive time series data for nine global regions. Extrapolation of historical trends without policy-driven limitations has China responsible for about half of global CO2 emissions by the middle of the twenty-first century. Results are presented for three possible actions taken by China to limit global average temperature increase to levels it considers to be to its advantage: (1) Help develop low-carbon energy technology broadly competitive with unbridled carbon emissions from burning fossil fuels; (2) Entice other countries to join in limiting use of what would otherwise be economically competitive fossil fuels; (3) Apply geo-engineering techniques such as stratospheric sulfur injection to limit global average temperature increase, without a major global reduction in carbon emissions. Taking into account China’s expected influence and approach to limiting the impact of anthropogenic climate change allows for a narrower range of possible outcomes than for a set of scenarios that are not constrained by analysis of likely policy-driven limitations. While China could hold back on implementing geoengineering given a remarkable amount of international cooperation on limiting fossil carbon burning, an outcome where geoengineering is used to delay the perceived need to limit the atmospheric CO2 concentration may be difficult to avoid. Full article
(This article belongs to the Special Issue Challenges in Alternative Energy)
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Open AccessArticle Innovative Promotion of Renewable Energy Development for Challenging Sustainable Low-Carbon Society: Case Study of Pingtung County, Taiwan
Challenges 2014, 5(1), 26-34; doi:10.3390/challe5010026
Received: 20 November 2013 / Revised: 30 December 2013 / Accepted: 31 December 2013 / Published: 8 January 2014
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Abstract
Pingtung County, located in the southernmost part of Taiwan, has been selected as one of the Smarter Cities Challenge by the International Business Machines (IBM) in 2013 due to its innovative promotion for renewable energy exploitation in recent years. In this regard, the
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Pingtung County, located in the southernmost part of Taiwan, has been selected as one of the Smarter Cities Challenge by the International Business Machines (IBM) in 2013 due to its innovative promotion for renewable energy exploitation in recent years. In this regard, the objective of this paper will be to present an in-depth analysis of the success of environmental sustainability efforts through aggressive measures and profitable plans by this tropical county. The description in the paper is, thus, summarized on the central regulations and economic measures for promoting renewable energy in Taiwan, focusing on the feed-in tariff (FIT). Then, some innovative promotion plans for renewable energy in Pinugtung County, including swine-derived biogas-to-power and “Raise Water, Grow Electricity”, were further addressed to show the preliminary results under the funding supports of the central and local governments. With a practical basis of the total swine population (around 433,000 heads), from the farm scale of over 5,000 heads in Pingtung County, a preliminary analysis showed the annual benefits: methane reduction of 2.2 Gg, electricity generation of 8.3 × 106 kilowatt-hour (kW-h), equivalent electricity charge saving of 8.3 × 105 US Dollar (USD), and equivalent carbon dioxide mitigation of 50.9 thousand tons (Gg). Full article
Open AccessArticle An Exploratory Analysis of Stream Teratogenicity and Human Health Using Zebrafish Whole-Sediment Toxicity Test
Challenges 2014, 5(1), 75-97; doi:10.3390/challe5010075
Received: 25 October 2013 / Revised: 18 January 2014 / Accepted: 8 February 2014 / Published: 17 February 2014
Cited by 2 | PDF Full-text (805 KB) | HTML Full-text | XML Full-text
Abstract
This study demonstrates a novel application of effect-based toxicity testing for streams that may provide indications of co-perturbation to ecological and human health. For this study, a sediment contact assay using zebrafish (Danio rerio) embryos was adapted to serve as an indicator
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This study demonstrates a novel application of effect-based toxicity testing for streams that may provide indications of co-perturbation to ecological and human health. For this study, a sediment contact assay using zebrafish (Danio rerio) embryos was adapted to serve as an indicator of teratogenic stress within river sediments. Sediment samples were collected from Lake Michigan tributary watersheds. Sediment contact assay responses were then compared to prevalence of congenital heart disease (CHD) and vital statistic birth indicators aggregated from civil divisions associated with the watersheds. Significant risk relationships were detected between variation in early life-stage (ELS) endpoints of zebrafish embryos 72 h post-fertilization and the birth prevalence of human congenital heart disease, low birthweight and infant mortality. Examination of principal components of ELS endpoints suggests that variance related to embryo heart and circulatory malformations is most closely associated with human CHD prevalence. Though toxicity assays are sometimes used prospectively, this form of investigation can only be conducted retrospectively. These results support the hypothesis that bioassays normally used for ecological screening can be useful as indicators of environmental stress to humans and expand our understanding of environmental–human health linkages. Full article
(This article belongs to the Special Issue Water Quality in the City)
Open AccessArticle Benefits and Challenges Associated with the Development of Forest-Based Bioenergy Projects in India: Results from an Expert Survey
Challenges 2014, 5(1), 100-111; doi:10.3390/challe5010100
Received: 25 July 2013 / Revised: 14 February 2014 / Accepted: 17 February 2014 / Published: 7 March 2014
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Abstract
Development of energy systems, based on forest biomass, is a challenging issue in India. The study investigated perceptions of fifty-five Indian Forest Service (IFS) officers in relation to the potential benefits and challenges associated with the development of forest-based bioenergy (FBE) projects in
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Development of energy systems, based on forest biomass, is a challenging issue in India. The study investigated perceptions of fifty-five Indian Forest Service (IFS) officers in relation to the potential benefits and challenges associated with the development of forest-based bioenergy (FBE) projects in India when they participated in two training programs in Finland during 2010. They generally agreed that development of FBE projects could have beneficial impacts on job creation, income generation, rural development, and restoring ecological degradation. They perceived lack of public acceptance and political support, impacts on biodiversity, and lack of technologies and infrastructure as the considerable challenges to the development of FBE projects in India. The study could provide some policy directions towards developing the FBE sector in India. It recommends conducting further studies to include a larger group of experts and other stakeholders to investigate the broader societal perceptions of FBE projects in India. In addition, the study also recommends building the capacity of the IFS officers so that they can play a key role from the government side for developing the FBE sector in the country. Full article
(This article belongs to the Special Issue Challenges in Alternative Energy)
Open AccessArticle Stormwater Quality Characteristics in (Dutch) Urban Areas and Performance of Settlement Basins
Challenges 2014, 5(1), 112-122; doi:10.3390/challe5010112
Received: 31 August 2013 / Revised: 5 March 2014 / Accepted: 6 March 2014 / Published: 19 March 2014
Cited by 1 | PDF Full-text (323 KB) | HTML Full-text | XML Full-text
Abstract
Stormwaters, flowing into storm sewers, are known to significantly increase the annual pollutant loads entering urban receiving waters and this results in significant degradation of the receiving water quality. Knowledge of the characteristics of stormwater pollution enables urban planners to incorporate the most
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Stormwaters, flowing into storm sewers, are known to significantly increase the annual pollutant loads entering urban receiving waters and this results in significant degradation of the receiving water quality. Knowledge of the characteristics of stormwater pollution enables urban planners to incorporate the most appropriate stormwater management strategies to mitigate the effects of stormwater pollution on downstream receiving waters. This requires detailed information on stormwater quality, such as pollutant types, sediment particle size distributions, and how soluble pollutants and heavy metals attach themselves to sediment particles. This study monitored stormwater pollution levels at over 150 locations throughout the Netherlands. The monitoring has been ongoing for nearly 15 years and a total of 7,652 individual events have been monitored to date. This makes the database the largest stormwater quality database in Europe. The study compared the results to those presented in contemporary international stormwater quality research literature. The study found that the pollution levels at many of the Dutch test sites did not meet the requirements of the European Water Framework Directive (WFD) and Dutch Water Quality Standards. Results of the study are presented and recommendations are made on how to improve water quality with the implementation of Sustainable Urban Drainage Systems (SUDS) devices. Full article
Open AccessArticle Changes in Acid Herbicide Concentrations in Urban Streams after a Cosmetic Pesticides Ban
Challenges 2014, 5(1), 138-151; doi:10.3390/challe5010138
Received: 3 October 2013 / Revised: 25 February 2014 / Accepted: 7 March 2014 / Published: 31 March 2014
Cited by 3 | PDF Full-text (873 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Surface water concentrations of the acid herbicides 2,4-D, dicamba and mecoprop were measured in ten urban Ontario streams before (2003–2008) and after (2009–2012) a ban on the sale and use of pesticides for cosmetic (non-essential) purposes. Frequencies of detection (2003–2012) were 98%, 96%
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Surface water concentrations of the acid herbicides 2,4-D, dicamba and mecoprop were measured in ten urban Ontario streams before (2003–2008) and after (2009–2012) a ban on the sale and use of pesticides for cosmetic (non-essential) purposes. Frequencies of detection (2003–2012) were 98%, 96% and nearly 100%, respectively for 2,4-D, dicamba and mecoprop. Concentrations were typically in the ng L−1 range, although periodic spikes in the µg L−1 range were observed. Concentrations in a majority of the study streams decreased significantly following the cosmetic pesticides ban. Concentrations decreased from 16% to 92% depending on the stream and herbicide. The presence of these herbicides in urban streams was likely a result of urban applications. Concentrations were significantly related to population density or urban land cover, and the relative proportion of the three herbicides observed in urban stream water approximated the ratios found in pesticide products formulated for urban use. Longer-term trends indicate that decreases in stream water herbicide concentrations may have preceded the ban and may be related to increased public awareness of pesticide issues and voluntary reductions in urban pesticide use. Full article
(This article belongs to the Special Issue Water Quality in the City)
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Open AccessArticle CO Self-Shielding as a Mechanism to Make 16O-Enriched Solids in the Solar Nebula
Challenges 2014, 5(1), 152-158; doi:10.3390/challe5010152
Received: 1 April 2014 / Revised: 8 May 2014 / Accepted: 13 May 2014 / Published: 21 May 2014
Cited by 2 | PDF Full-text (160 KB) | HTML Full-text | XML Full-text
Abstract
Photochemical self-shielding of CO has been proposed as a mechanism to produce solids observed in the modern, 16O-depleted solar system. This is distinct from the relatively 16O-enriched composition of the solar nebula, as demonstrated by the oxygen isotopic composition of the
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Photochemical self-shielding of CO has been proposed as a mechanism to produce solids observed in the modern, 16O-depleted solar system. This is distinct from the relatively 16O-enriched composition of the solar nebula, as demonstrated by the oxygen isotopic composition of the contemporary sun. While supporting the idea that self-shielding can produce local enhancements in 16O-depleted solids, we argue that complementary enhancements of 16O-enriched solids can also be produced via C16O-based, Fischer-Tropsch type (FTT) catalytic processes that could produce much of the carbonaceous feedstock incorporated into accreting planetesimals. Local enhancements could explain observed 16O enrichment in calcium-aluminum-rich inclusions (CAIs), such as those from the meteorite, Isheyevo (CH/CHb), as well as in chondrules from the meteorite, Acfer 214 (CH3). CO self-shielding results in an overall increase in the 17O and 18O content of nebular solids only to the extent that there is a net loss of C16O from the solar nebula. In contrast, if C16O reacts in the nebula to produce organics and water then the net effect of the self-shielding process will be negligible for the average oxygen isotopic content of nebular solids and other mechanisms must be sought to produce the observed dichotomy between oxygen in the Sun and that in meteorites and the terrestrial planets. This illustrates that the formation and metamorphism of rocks and organics need to be considered in tandem rather than as isolated reaction networks. Full article
(This article belongs to the Special Issue Challenges in Astrobiology)
Open AccessArticle Assessing the Possibility of Biological Complexity on Other Worlds, with an Estimate of the Occurrence of Complex Life in the Milky Way Galaxy
Challenges 2014, 5(1), 159-174; doi:10.3390/challe5010159
Received: 19 March 2014 / Revised: 19 May 2014 / Accepted: 20 May 2014 / Published: 28 May 2014
Cited by 7 | PDF Full-text (297 KB) | HTML Full-text | XML Full-text
Abstract
Rational speculation about biological evolution on other worlds is one of the outstanding challenges in astrobiology. With the growing confirmation that multiplanetary systems abound in the universe, the prospect that life occurs redundantly throughout the cosmos is gaining widespread support. Given the enormous
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Rational speculation about biological evolution on other worlds is one of the outstanding challenges in astrobiology. With the growing confirmation that multiplanetary systems abound in the universe, the prospect that life occurs redundantly throughout the cosmos is gaining widespread support. Given the enormous number of possible abodes for life likely to be discovered on an ongoing basis, the prospect that life could have evolved into complex, macro-organismic communities in at least some cases merits consideration. Toward that end, we here propose a Biological Complexity Index (BCI), designed to provide a quantitative estimate of the relative probability that complex, macro-organismic life forms could have emerged on other worlds. The BCI ranks planets and moons by basic, first-order characteristics detectable with available technology. By our calculation only 11 (~1.7%) of the extrasolar planets known to date have a BCI above that of Europa; but by extrapolation, the total of such planets could exceed 100 million in our galaxy alone. This is the first quantitative assessment of the plausibility of complex life throughout the universe based on empirical data. It supports the view that the evolution of complex life on other worlds is rare in frequency but large in absolute number. Full article
(This article belongs to the Special Issue Challenges in Astrobiology)
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Open AccessArticle Enantioselective Crystallization of Sodium Chlorate in the Presence of Racemic Hydrophobic Amino Acids and Static Magnetic Fields
Challenges 2014, 5(1), 175-192; doi:10.3390/challe5010175
Received: 27 March 2014 / Revised: 7 May 2014 / Accepted: 13 May 2014 / Published: 5 June 2014
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Abstract
We study the bias induced by a weak (200 mT) external magnetic field on the preferred handedness of sodium chlorate crystals obtained by slow evaporation at ambient conditions of its saturated saline solution with 20 ppm of added racemic (dl) hydrophobic amino acids.
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We study the bias induced by a weak (200 mT) external magnetic field on the preferred handedness of sodium chlorate crystals obtained by slow evaporation at ambient conditions of its saturated saline solution with 20 ppm of added racemic (dl) hydrophobic amino acids. By applying the Fisher test to pairs of experiments with opposing magnetic field orientation we conclude, with a confidence level of 99.7%, that at the water-air interface of this saline solution there is an enantioselective magnetic interaction that acts upon racemic mixtures of hydrophobic chiral amino acids. This interaction has been observed with the three tested racemic hydrophobic amino acids: dl-Phe, dl-Try and dl-Trp, at ambient conditions and in spite of the ubiquitous chiral organic contamination. This enantioselective magnetic dependence is not observed when there is only one handedness of added chiral amino-acid, if the added amino acid is not chiral or if there is no additive. This effect has been confirmed with a double blind test. This novel experimental observation may have implications for our view of plausible initial prebiotic scenarios and of the roles of the geomagnetic field in homochirality in the biosphere. Full article
(This article belongs to the Special Issue Challenges in Astrobiology)
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Review

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Open AccessReview Climate Strategic Soil Management
Challenges 2014, 5(1), 43-74; doi:10.3390/challe5010043
Received: 9 September 2013 / Revised: 11 December 2013 / Accepted: 14 December 2013 / Published: 13 February 2014
Cited by 3 | PDF Full-text (1143 KB) | HTML Full-text | XML Full-text
Abstract
The complex and strong link between soil degradation, climate change and food insecurity is a global challenge. Sustainable agricultural systems must be integral to any agenda to address climate change and variability, improve renewable fresh water supply and quality, restore degraded soils and
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The complex and strong link between soil degradation, climate change and food insecurity is a global challenge. Sustainable agricultural systems must be integral to any agenda to address climate change and variability, improve renewable fresh water supply and quality, restore degraded soils and ecosystems and advance food security. These challenges are being exacerbated by increasing population and decreasing per capita arable land area and renewable fresh water supply, the increasing frequency of extreme events, the decreasing resilience of agroecosystems, an increasing income and affluent lifestyle with growing preference towards meat-based diet and a decreasing soil quality and use efficiency of inputs. Reversing these downward spirals implies the implementation of proven technologies, such as conservation agriculture, integrated nutrient management, precision agriculture, agroforestry systems, etc. Restoration of degraded soil and desertified ecosystems and the creation of positive soil and ecosystem C budgets are important. Urban agriculture and green roofs can reduce the energy footprint of production chains for urban and non-urban areas and enhance the recycling of by-products. Researchable priorities include sustainable land use and soil/water management options, judicious soil governance and modus operandi towards payments to land managers for the provisioning of ecosystem services. Full article
(This article belongs to the Special Issue Food Security)

Other

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Open AccessConcept Paper Electromagnetic Wave Scattering by Small Impedance Particles of an Arbitrary Shape and Applications
Challenges 2014, 5(1), 35-42; doi:10.3390/challe5010035
Received: 22 September 2013 / Accepted: 16 January 2014 / Published: 7 February 2014
Cited by 2 | PDF Full-text (110 KB) | HTML Full-text | XML Full-text
Abstract
The proposal deals with electromagnetic (EM) wave scattering by one and many small impedance particles of an arbitrary shape. Analytic formula is derived for EM wave scattering by one small impedance particle of an arbitrary shape and an integral equation for the effective
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The proposal deals with electromagnetic (EM) wave scattering by one and many small impedance particles of an arbitrary shape. Analytic formula is derived for EM wave scattering by one small impedance particle of an arbitrary shape and an integral equation for the effective field in the medium where many such particles are embedded. These results are applied for creating a medium with a desired refraction coefficient. The proposed theory has no analogs in the literature. (Mathematical Subject Classiffication: 35J05, 35J25, 65N12, 78A25, 78A48.) Full article
Open AccessConcept Paper Moving Towards Sustainable and Resilient Smart Water Grids
Challenges 2014, 5(1), 123-137; doi:10.3390/challe5010123
Received: 5 October 2013 / Revised: 26 February 2014 / Accepted: 5 March 2014 / Published: 21 March 2014
Cited by 4 | PDF Full-text (244 KB) | HTML Full-text | XML Full-text
Abstract
Urban water systems face sustainability and resiliency challenges including water leaks, over-use, quality issues, and response to drought and natural disasters. Information and communications technology (ICT) could help address these challenges through the development of smart water grids that network and automate monitoring
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Urban water systems face sustainability and resiliency challenges including water leaks, over-use, quality issues, and response to drought and natural disasters. Information and communications technology (ICT) could help address these challenges through the development of smart water grids that network and automate monitoring and control devices. While progress is being made on technology elements, as a system, the smart water grid has received scant attention. This article aims to raise awareness of the systems-level idea of smart water grids by reviewing the technology elements and their integration into smart water systems, discussing potential sustainability and resiliency benefits, and challenges relating to the adoption of smart water grids. Water losses and inefficient use stand out as promising areas for applications of smart water grids. Potential barriers to the adoption of smart water grids include lack of funding for research and development, economic disincentives as well as institutional and political structures that favor the current system. It is our hope that future work can clarify the benefits of smart water grids and address challenges to their further development. Full article

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