Open AccessArticle
A Linear Bayesian Updating Model for Probabilistic Spatial Classification
Challenges 2016, 7(2), 21; doi:10.3390/challe7020021 (registering DOI) -
Abstract
Categorical variables are common in spatial data analysis. Traditional analytical methods for deriving probabilities of class occurrence, such as kriging-family algorithms, have been hindered by the discrete characteristics of categorical fields. To solve the challenge, this study introduces the theoretical backgrounds of the
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Categorical variables are common in spatial data analysis. Traditional analytical methods for deriving probabilities of class occurrence, such as kriging-family algorithms, have been hindered by the discrete characteristics of categorical fields. To solve the challenge, this study introduces the theoretical backgrounds of the linear Bayesian updating (LBU) model for spatial classification through an expert system. The main purpose of this paper is to present the solid theoretical foundations of the LBU approach. Since the LBU idea is originated from aggregating expert opinions and is not restricted to conditional independent assumption (CIA), it may prove to be reasonably adequate for analyzing complex geospatial data sets, such as remote sensing images or area-class maps. Full article
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Open AccessOpinion
Technical Problem Identification for the Failures of the Liberty Ships
Challenges 2016, 7(2), 20; doi:10.3390/challe7020020 -
Abstract
The U.S. Liberty Ship Building Program in World War II set a record—a total of 2700 Liberty Ships were built in 6 years, in order to support the battle against Nazi-Germany. However, numerous vessels suffered sudden fracture, some of them being split in
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The U.S. Liberty Ship Building Program in World War II set a record—a total of 2700 Liberty Ships were built in 6 years, in order to support the battle against Nazi-Germany. However, numerous vessels suffered sudden fracture, some of them being split in half. This paper demonstrates and investigation of the Liberty Ships failure and problems, which reveals that the failures are caused by a combination of three factors. The welds produced by largely unskilled work force contain crack type flaws. Beyond these cracks, another important reason for failure associated with welding is the hydrogen embitterment; most of the fractures initiate at deck square hatch corners where there is a stress concentration; and the ship steel has fairly poor Charpy-Impact tested fracture toughness. It has been admitted that, although the numerous catastrophic failures were a painful experience, the failures of the Liberty Ships caused significant progress in the study of fracture mechanics. Considering their effect, the Liberty Ships are still a success. Full article
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Open AccessReview
Challenges in Specialty Coffee Processing and Quality Assurance
Challenges 2016, 7(2), 19; doi:10.3390/challe7020019 -
Abstract
Coffee is an important crop that assures a sustainable economy to farmers in tropical regions. A dramatic concern for coffee production is currently represented by climate change, which threatens the survival of Coffea arabica cultivation worldwide and imposes modifications of the agronomic practices
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Coffee is an important crop that assures a sustainable economy to farmers in tropical regions. A dramatic concern for coffee production is currently represented by climate change, which threatens the survival of Coffea arabica cultivation worldwide and imposes modifications of the agronomic practices to prevent this risk. The quality of coffee beans depends on optimized protocols of cultivation, ripe berries collection, and removal of the outer fruit layers by dry or wet processes and moisture reduction. Storage and shipment represent two steps where bean quality needs to be preserved by preventing fungal contamination that may impact the final product and form mycotoxins, mainly ochratoxin A. In this review, we describe the challenges faced by the coffee industry to guarantee quality from production to roasting and brewing. An overview of novel technologies, such as the application of starter cultures in fermentation and the exploitation of industrial enzymes in accelerating the process of flavour development in coffee beans, is given. Moreover, the results of studies on microbial populations on coffee and the differences found in fungi, yeasts and bacteria composition among the investigations, are summarized. In particular, this review describes new attempts to contain the development of mycotoxigenic fungi, through the application of antagonistic microorganisms such as S. cerevisiae. The new wave of specialty coffees, i.e., those with a cupping score higher than 85/100, is also presented. It is shown how, through careful coffee production methods and controlled fermentation processes, coffee producers may increase their income by assuring high standards of quality and high added value for the coffee experience sector. Full article
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Open AccessArticle
Optimization of Plating Conditions for the Determination of Polonium Using Copper Foils
Challenges 2016, 7(2), 18; doi:10.3390/challe7020018 -
Abstract
The technique of adsorption of polonium onto metal surfaces by spontaneous deposition has found applications in the analysis of environmental samples such as marine sediments, foodstuff, water, and tobacco since the 1960s. Silver foil has been preferred by many scientists but can become
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The technique of adsorption of polonium onto metal surfaces by spontaneous deposition has found applications in the analysis of environmental samples such as marine sediments, foodstuff, water, and tobacco since the 1960s. Silver foil has been preferred by many scientists but can become quite expensive for routine analysis. Deposition onto copper was first proposed in the 1970s, but has remained poorly studied. In the present study, the cost-effective and rapid optimum conditions necessary for the optimal recovery of Po from aqueous solutions during spontaneous deposition onto copper foils was evaluated while minimizing the deposition of Bi and Pb, which may interfere with subsequent analyses. A series of experiments was performed to determine adsorption yields for Po, Bi, and Pb to copper foils for a range of pH values from 1.0 to 5.5, with and without stable Bi and Pb carriers. Different methods for cleaning the copper foils were also compared. After initial measurements, Po, Bi, and Pb were desorbed from the disc in plating solutions without added activity. At higher pH values (3.0 and 5.5), less Bi was adsorbed to the copper foils, and subsequent desorption removed up to 99.1% of the plated Bi. The polonium yield remained fairly constant at all pH values and was unaffected by the desorption process. There was also no measureable increase in the polonium activity after 33 days, suggesting that Bi and Pb were not significantly co-deposited. All three cleaning methods performed well, whereas uncleaned foils in the same solution showed limited uptake. The use of copper foil under the optimum conditions described here could provide a valuable alternative to the use of silver in 210Po analyses. Full article
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Open AccessFeature PaperArticle
Field Prototype of the ENEA Neutron Active Interrogation Device for the Detection of Dirty Bombs
Challenges 2016, 7(2), 17; doi:10.3390/challe7020017 -
Abstract
The Italian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA) Neutron Active Interrogation (NAI) device is a tool designed to improve CBRNE defense. It is designed to uncover radioactive and nuclear threats including those in the form of Improvised Explosive
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The Italian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA) Neutron Active Interrogation (NAI) device is a tool designed to improve CBRNE defense. It is designed to uncover radioactive and nuclear threats including those in the form of Improvised Explosive Devices (IEDs), the so-called “dirty bombs”. The NAI device, at its current development stage, allows to detect 6 g of 235U hidden in a package. It is easily transportable, light in weight, and with a real-time response. Its working principle is based on two stages: (1) an “active” stage in which neutrons are emitted by a neutron generator to interact with the item under inspection, and (2) a “passive” stage in which secondary neutrons are detected originating a signal that, once processed, allows recognition of the offence. In particular, a clear indication of the potential threat is obtained by a dedicated software based on the Differential Die-Away Time Analysis method. Full article
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Open AccessConcept Paper
Soft Energy Paths Revisited: Politics and Practice in Energy Technology Transitions
Challenges 2016, 7(2), 16; doi:10.3390/challe7020016 -
Abstract
This paper argues that current efforts to study and advocate for a change in energy technologies to reduce their climate and other environmental impacts often ignore the political, social, and bodily implications of energy technology choices. Framing renewable energy technologies exclusively in terms
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This paper argues that current efforts to study and advocate for a change in energy technologies to reduce their climate and other environmental impacts often ignore the political, social, and bodily implications of energy technology choices. Framing renewable energy technologies exclusively in terms of their environmental benefits dismisses important questions about how energy infrastructures can be designed to correspond to democratic forms of socio-politics, forms of social organization that involve independence in terms of meeting energy needs, resilience in terms of adapting to change, participatory decision making and control, equitable distribution of knowledge and efficacy, and just distribution of ownership. Recognizing technological choices as political choices brings explicit attention to the kinds of socio-political restructuring that could be precipitated through a renewable energy technology transition. This paper argues that research on energy transitions should consider the political implications of technological choices, not just the environmental consequences. Further, emerging scholarship on energy practices suggests that social habits of energy usage are themselves political, in that they correspond to and reinforce particular arrangements of power. Acknowledging the embedded politics of technology, as the decades’ old concept of soft path technologies encourages, and integrating insights on the politics of technology with insights on technological practices, can improve future research on energy policy and public perceptions of energy systems. This paper extends insights regarding the socio-political implications of energy paths to consider how understandings of energy technologies as constellations of embedded bodily practices can help further develop our understanding of the consequences of energy technologies, consequences that move beyond environmental implications to the very habits and behaviors of patterned energy usage, which are themselves arguably political. This paper calls for future research that involves explicit examination of the relationship between technologies, socio-political distributions of power and access to energy resources, the social organization of energy practices, and options for energy transitions not just in terms of energy source, but also in terms of scale, design, and modes of ownership and control. Full article
Open AccessConcept Paper
Putting Soil Security on the Policy Agenda: Need for a Familiar Framework
Challenges 2016, 7(2), 15; doi:10.3390/challe7020015 -
Abstract
Soils generate agricultural, environmental, and socio-economic benefits that are vital to human life. The enormity of threats to global soil stocks raises the imperative for securing this vital resource. To contribute to the security framing and advancement of the soil security concept and
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Soils generate agricultural, environmental, and socio-economic benefits that are vital to human life. The enormity of threats to global soil stocks raises the imperative for securing this vital resource. To contribute to the security framing and advancement of the soil security concept and discourse, this paper provides a working definition and proposes dimensions that can underpin the conceptualization of soil security. In this paper, soil security refers to safeguarding and improving the quality, quantity and functionality of soil stocks from critical and pervasive threats in order to guarantee the availability, access, and utilization of soils to sustainably generate productive goods and ecosystem services. The dimensions proposed are availability, accessibility, utilization, and stability, which are obviously similar to the dimensions of food security. Availability refers to the quality and spatial distribution of soils of a given category. Accessibility relates to the conditions or mechanisms by which actors negotiate and gain entitlements to occupy and use a given soil. Utilization deals with the use or purpose to which a given soil is put and the capacity to manage and generate optimal private and public benefits from the soil. Finally, stability refers to the governance mechanisms that safeguard and improve the first three dimensions. These dimensions, their interactions, and how they can be operationalized in a strategy to secure soils are presented and discussed. Full article
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Open AccessArticle
Validation of a Miniaturized Spectrometer for Trace Detection of Explosives by Surface-Enhanced Raman Spectroscopy
Challenges 2016, 7(2), 14; doi:10.3390/challe7020014 -
Abstract
Surface-enhanced Raman spectroscopy (SERS) measurements of some common military explosives were performed with a table-top micro-Raman system integrated with a Serstech R785 miniaturized device, comprising a spectrometer and detector for near-infrared (NIR) laser excitation (785 nm). R785 was tested as the main component
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Surface-enhanced Raman spectroscopy (SERS) measurements of some common military explosives were performed with a table-top micro-Raman system integrated with a Serstech R785 miniaturized device, comprising a spectrometer and detector for near-infrared (NIR) laser excitation (785 nm). R785 was tested as the main component of a miniaturized SERS detector, designed for in situ and stand-alone sensing of molecules released at low concentrations, as could happen in the case of traces of explosives found in an illegal bomb factory, where solid microparticles of explosives could be released in the air and then collected on the sensor’s surface, if placed near the factory, as a consequence of bomb preparation. SERS spectra were obtained, exciting samples in picogram quantities on specific substrates, starting from standard commercial solutions. The main vibrational features of each substance were clearly identified also in low quantities. The amount of the sampled substance was determined through the analysis of scanning electron microscope images, while the spectral resolution and the detector sensitivity were sufficiently high to clearly distinguish spectra belonging to different samples with an exposure time of 10 s. A principal component analysis procedure was applied to the experimental data to understand which are the main factors affecting spectra variation across different samples. The score plots for the first three principal components show that the examined explosive materials can be clearly classified on the basis of their SERS spectra. Full article
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Open AccessArticle
Potential for Reuse of E-Plastics through Processing by Compression Molding
Challenges 2016, 7(1), 13; doi:10.3390/challe7010013 -
Abstract
The amounts of e-waste, consisting of metal (e-metals) and plastic (e-plastics) streams from electronic goods, are increasing in the United States and elsewhere. The e-metals waste streams are being recycled to a reasonable degree due to the value of precious metals. E-plastic waste
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The amounts of e-waste, consisting of metal (e-metals) and plastic (e-plastics) streams from electronic goods, are increasing in the United States and elsewhere. The e-metals waste streams are being recycled to a reasonable degree due to the value of precious metals. E-plastic waste streams currently are not recycled or reused to a significant extent. As a result, most e-plastics are disposed of by landfilling or thermal treatment, or sent overseas for alleged recycling or reuse, any of which could result in unsafe worker exposure and release into the environment. Two of the major barriers to e-plastics’ reuse or recycling are the mixed plastic content and the presence in the e-plastics of flame retardants (FR), of which two classes in particular, the brominated flame retardants (BFR) and organo-phosphorus flame retardants (OPFR), have associated health concerns. The major goal of this project is to investigate the possibility of direct reuse of e-plastics in compression molding. Preliminary data generated have identified a molding procedure that yields remanufactured e-plastics having a tensile strength of 29.3 MPa. This moderate strength level is suspected to be due to inclusions of plastic bits that did not melt and internal voids from out-gassing. Handheld X-ray fluorescence (XRF) was utilized to characterize elemental components in the e-plastics tested for compression molding. Several high “hits” for Br were found that could not be predicted visually. The preliminary XRF data for BFR and OPFR in this work are helpful for environmental and occupational hazard assessments of compression molding activities. Additionally, methods are suggested to characterize the metals, BFR, and OPFR content of the e-plastics using several different additional laboratory analytical techniques to determine the suitability for cost-effective and easy-to-use technologies. Full article
Open AccessArticle
Tie-Up Cycles in Long-Term Mating. Part I: Theory
Challenges 2016, 7(1), 12; doi:10.3390/challe7010012 -
Abstract
In this paper, we propose a new approach to couple formation and dynamics that abridges findings from sexual strategies theory and attachment theory to develop a framework where the sexual and emotional aspects of mating are considered in their strategic interaction. Our approach
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In this paper, we propose a new approach to couple formation and dynamics that abridges findings from sexual strategies theory and attachment theory to develop a framework where the sexual and emotional aspects of mating are considered in their strategic interaction. Our approach presents several testable implications, some of which find interesting correspondences in the existing literature. Our main result is that, according to our approach, there are six typical dynamic interaction patterns that are more or less conducive to the formation of a stable couple, and that set out an interesting typology for the analysis of real (as well as fictional, as we will see in the second part of the paper) mating behaviors and dynamics. Full article
Open AccessOpinion
Alternative Energies and Fossil Fuels in the Bioeconomy Era: What is Needed in the Next Five Years for Real Change
Challenges 2016, 7(1), 11; doi:10.3390/challe7010011 -
Abstract Sustainable biomass feedstock is the key to sustainable biofuels.[...] Full article
Open AccessArticle
Modeling Autonomous Decision-Making on Energy and Environmental Management Using Petri-Net: The Case Study of a Community in Bandung, Indonesia
Challenges 2016, 7(1), 9; doi:10.3390/challe7010009 -
Abstract
Autonomous decision-making in this study is defined as the process where decision-makers have the freedom and ability to find problems, select goals, and make decisions for achieving the selected problems/goals by themselves. Autonomous behavior is considered significant for achieving decision implementation, especially in
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Autonomous decision-making in this study is defined as the process where decision-makers have the freedom and ability to find problems, select goals, and make decisions for achieving the selected problems/goals by themselves. Autonomous behavior is considered significant for achieving decision implementation, especially in the context of energy and environmental management, where multiple stakeholders are involved and each stakeholder holds valuable local information for making decisions. This paper aims to build a structured process in modeling the autonomous decision-making. A practical decision-making process in waste-to-energy conversion activities in a community in Bandung, Indonesia, is selected as a case study. The decision-making process here is considered as a discrete event system, which is then represented as a Petri-net model. First, the decision-making process in the case study is decomposed into discrete events or decision-making stages, and the stakeholders’ properties in each stage are extracted from the case study. Second, several stakeholder properties that indicate autonomous behavior are identified as autonomous properties. Third, presented is a method to develop the decision-making process as a Petri-net model. The model is utilized for identifying the critical points for verifying the performance of the derived Petri-net. Full article
Open AccessOpinion
Flaws and Drawbacks in Present Regulation and the Need to Take Action and Support the Renewable Energies Policies in Italy
Challenges 2016, 7(1), 10; doi:10.3390/challe7010010 -
Abstract Renewable energies is an important sector that needs to be sustained and increased by the action of policies and economic support.[...] Full article
Open AccessLetter
Policies Supporting Renewable Energies Uses: The Next Big Challenge
Challenges 2016, 7(1), 8; doi:10.3390/challe7010008 -
Abstract
The question in the referendum on 17 April is: “At the end of the concessions presently authorized for extraction plants in the sea, at a distance within 12 km from the coast of Italy, are you in favor of stopping the extraction, even
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The question in the referendum on 17 April is: “At the end of the concessions presently authorized for extraction plants in the sea, at a distance within 12 km from the coast of Italy, are you in favor of stopping the extraction, even if there is still some methane or oil to be extracted?”.[...] Full article
Open AccessOpinion
Fossil Fuels, Let’s Leave Them under Earth. Four Reasons to Vote “Yes” at the Italian Referendum on Drilling
Challenges 2016, 7(1), 7; doi:10.3390/challe7010007 -
Abstract
The referendum that will be held on 17 April 2016 is calling Italians to express their willingness on an aspect of licensing the sea drilling activities: The end of the licenses to the offshore exploitation of fossil fuel resources within the 12 miles
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The referendum that will be held on 17 April 2016 is calling Italians to express their willingness on an aspect of licensing the sea drilling activities: The end of the licenses to the offshore exploitation of fossil fuel resources within the 12 miles from the coast. Full article
Open AccessEditorial
On Energy Resources, Climate Change, Fossil Fuels, and Drilling. Challenges in Tackling Problems by Governments in Europe and USA
Challenges 2016, 7(1), 6; doi:10.3390/challe7010006 -
Abstract
This month in Italy a public consultation will decide (by majority, in case 50% of voters will participate) whether to renew the ongoing concessions between Italian government and drilling companies at the end of their contracts, even if the fossil fuels have not
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This month in Italy a public consultation will decide (by majority, in case 50% of voters will participate) whether to renew the ongoing concessions between Italian government and drilling companies at the end of their contracts, even if the fossil fuels have not been extracted completely.[...] Full article
Open AccessArticle
Bridging the Gap between Eco-Design and the Human Thinking System
Challenges 2016, 7(1), 5; doi:10.3390/challe7010005 -
Abstract
Technological progress has enabled widespread adoption and use of consumer electronics, changing how global society lives and works. This progress has come with immense environmental cost, including extraction of scarce materials, consumption of fossil fuels, and growing e-waste challenges. Eco-design has emerged as
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Technological progress has enabled widespread adoption and use of consumer electronics, changing how global society lives and works. This progress has come with immense environmental cost, including extraction of scarce materials, consumption of fossil fuels, and growing e-waste challenges. Eco-design has emerged as a promising approach to reduce the environmental footprint of electronics by integrating sustainability-oriented decisions early in the product realization process. However, most approaches focus on the product itself, not on the consumer who ultimately decides how to purchase, use, maintain, and dispose of the device. This article presents a new framework to guide designers in developing products with features that encourage consumers to use them in an environmentally sustainable manner. The Sustainable Behavior Design (SBD) framework links common design concepts (ergonomic, emotional, preventative, and interaction design) with core aspects of the human thinking system to create features to make users aware of their behavior and decisions (reflective thinking) or result in sustainable behaviors even when users are unaware (automatic thinking). The SBD framework is demonstrated using a case study on a smartphone, a high demand product. The reimagined smartphone design integrates solutions addressing both automatic and reflective thinking systems, potentially reducing life cycle impacts by almost 30%. Full article
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Open AccessArticle
Practical Eco-Design and Eco-Innovation of Consumer Electronics—the Case of Mobile Phones
Challenges 2016, 7(1), 3; doi:10.3390/challe7010003 -
Abstract
Annually, it is estimated that about 4 billion units of consumer electronics for mobile communications are produced worldwide. This could lead to various ecological imbalances unless the design and disposal of the products are handled optimally. To illustrate how industry looks at and
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Annually, it is estimated that about 4 billion units of consumer electronics for mobile communications are produced worldwide. This could lead to various ecological imbalances unless the design and disposal of the products are handled optimally. To illustrate how industry looks at and responds to the increasing social awareness, this article describes how sustainability is successfully implemented in practice at a large Chinese company, developing and producing various kinds of electronic products used for communication. It also describes how a variety of eco-innovations and business models contribute to reducing the environmental impact; for example, through increased recovery and recycling. A new kind of eco-design procedure is presented along with a new methodology which shows how a mobile phone gradually becomes more sustainable from one generation to the next. The issues with and set-up of new eco-labeling schemes for mobile phones, eco-rating, is described in detail. The conclusion is that due to high competition between companies, the industry acts resourcefully and a lot is done to the save the ecological environment. Full article
Open AccessBrief Report
Use of Bacteriocinogenic Cultures without Inhibiting Cheese Associated Nonstarter Lactic Acid Bacteria; A Trial with Lactobacillus plantarum
Challenges 2016, 7(1), 4; doi:10.3390/challe7010004 -
Abstract
Bacteriocinogenic cultures can represent a natural way to increase the safety of cheeses made from raw milk, in which a relevant role in ripening and flavor formation is exerted by the nonstarter lactic acid bacteria (NSLAB). Since the latter can be inhibited by
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Bacteriocinogenic cultures can represent a natural way to increase the safety of cheeses made from raw milk, in which a relevant role in ripening and flavor formation is exerted by the nonstarter lactic acid bacteria (NSLAB). Since the latter can be inhibited by bacteriocin producers, this study evaluated to which extent a nisinogenic culture inoculated at low initial levels can affect the growth rate and peptide degradation activity of the nisin-sensitive cheese isolate Lactobacillus plantarum LZ by comparison with its isogenic variant, L. plantarum LZNI, with increased immunity to nisin. A growth delay of the nisin sensitive strain was observed only when its initial number was 100-fold lower than the nisin producer and nisin was added as an inducer of its own production. In this case, the amount of free α-amino groups was significantly different between cultures of L. plantarum LZ and LZNI only at Day 1. Reverse Phase High Performance Liquid Chromatography (RP-HPLC) highlighted a few differences between the peptide profiles of co-cultures L. plantarum LZ and LZNI. However, results showed that the bacteriocin producer did not dramatically influence the behavior of the sensitive NSLAB and that the evaluation of the effects on microbial contaminants in cheese is worthwhile. Full article
Open AccessReview
Challenges in Creating Evidence in Environmental Health Risk Assessments: The Example of Second-Hand Smoke
Challenges 2016, 7(1), 2; doi:10.3390/challe7010002 -
Abstract
Public health interventions are directed to influence the (state of a) risk factor, either by behavioral or environmental changes. Therefore, environmental health risk assessments are highly relevant for public health decision making and policy development. The credibility of an environmental health risk assessment
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Public health interventions are directed to influence the (state of a) risk factor, either by behavioral or environmental changes. Therefore, environmental health risk assessments are highly relevant for public health decision making and policy development. The credibility of an environmental health risk assessment depends, to a large extent, on the strength of the scientific evidence on which it is based. In this article, the main challenges for assessing the impact of a potential adverse health effect from an environmental pollutant are described. Second-hand smoke (SHS) was chosen to illustrate the current state of evidence. The assessment of the impact of potential adverse health effects from environmental risk factors is dependent on several issues, such as the hypothesized health outcome, the nature of the exposure, the dose-response-relationship and the variability and susceptibility of the exposed population. The example of SHS exposure highlights the need for evidence-based public health. Several challenges in terms of study design, assessment methods, as well as data analysis and synthesis with respect to the stratification of results, and consideration of bias and confounding exist. Future research needs to take into account which methods and techniques will be used to generate evidence for population-level decisions. Full article