High concentrations of floating neustonic life in the plastic-rich North Pacific Garbage Patch.

Floating life (obligate neuston) is a core component of the ocean surface food web. However, only 1 region of high neustonic abundance is known so far, the Sargasso Sea in the Subtropical North Atlantic gyre, where floating life provides critical habitat structure and ecosystem services. Here, we hypothesize that floating life is also concentrated in other gyres with converging surface currents. To test this hypothesis, we collected samples through the eastern North Pacific Subtropical Gyre in the area of the North Pacific "Garbage Patch" (NPGP) known to accumulate floating anthropogenic debris. We found that densities of floating life were higher inside the central NPGP than on its periphery and that there was a positive relationship between neuston abundance and plastic abundance for 3 out of 5 neuston taxa, Velella, Porpita, and Janthina. This work has implications for the ecology of subtropical oceanic gyre ecosystems.

Utilization strategy for algal bloom waste through co-digestion with kitchen waste: Comprehensive kinetic and metagenomic analysis.

Anaerobic co-digestion (AcoD) with kitchen waste (KW) is an alternative utilization strategy for algal bloom waste (AW). However, the kinetic characteristic and metabolic pathway during this process need to be explored further. This study conducted a comprehensive kinetic and metagenomic analysis for AcoD of AW and KW. A maximum co-digestion performance index (CPI) of 1.13 was achieved under the 12% AW addition. Co-digestion improved the total volatile fatty acids generation and the organic matter transformation efficiency. Kinetic analysis showed that the Superimposed model fit optimally (R2Adj = 0.9988-0.9995). The improvement of the kinetic process by co-digestion was mainly reflected in the increase of the methane production from slowly biodegradable components. Co-digestion enriched the cellulolytic bacterium Clostridium and the hydrogenotrophic methanogenic archaea Methanobacterium. Furthermore, for metagenome analysis, the abundance of key genes concerned in cellulose and lipid hydrolysis, pyruvate and methane metabolism were both increased in co-digestion process. This study provided a feasible process for the utilization of AW produced seasonally and a deeper understanding of the AcoD synergistic mechanism from kinetic and metagenomic perspectives.

Distribution and survival of pathogens from different waste components and bioaerosol traceability analysis in household garbage room.

Household garbage rooms release abundant bioaerosols and are an important source of pathogens; however, information on the distribution and survival patterns of pathogens in different waste components is limited. In this study, a culture method and 16S rRNA high-throughput sequencing were used to determine bacterial communities, culturable pathogens, and human bacterial pathogens (HBPs). The results showed that abundant culturable bacteria were detected in all waste types, and a large number of S. aureus was detected on the surface of recyclable wastes, whereas S. aureus, total coliforms, Salmonella, Enterococcus, and hemolytic bacteria were detected in food waste and other waste. The activities of these detected pathogenic bacteria decreased after 24 h of storage but re-activated within one week. Factors affecting the emergence of pathogens varied with different waste components. Sequencing results showed that Pseudomonas, Acinetobacter, and Burkholderia were abundant in the waste samples, whereas Achromobacter, Exiguobacteriums, Bordetella, and Corynebacterium were the primary pathogens in the bioaerosol and wall attachment. The results of traceability analysis showed that bioaerosol microbes were mainly derived from raw kitchen waste (5.98%) and plastic and paper contaminated with food waste (19.93%) in garbage rooms. In addition, bioaerosols were the main source of microflora in the wall attachment, which possessed high HBP diversity and required more attention. These findings will help in understanding the microbial hazards in different waste components and provide guidance for the control and risk reduction of bioaerosols during waste management and recycling.

Thermodynamic feasibility of shipboard conversion of marine plastics to blue diesel for self-powered ocean cleanup.

Collecting and removing ocean plastics can mitigate their environmental impacts; however, ocean cleanup will be a complex and energy-intensive operation that has not been fully evaluated. This work examines the thermodynamic feasibility and subsequent implications of hydrothermally converting this waste into a fuel to enable self-powered cleanup. A comprehensive probabilistic exergy analysis demonstrates that hydrothermal liquefaction has potential to generate sufficient energy to power both the process and the ship performing the cleanup. Self-powered cleanup reduces the number of roundtrips to port of a waste-laden ship, eliminating the need for fossil fuel use for most plastic concentrations. Several cleanup scenarios are modeled for the Great Pacific Garbage Patch (GPGP), corresponding to 230 t to 11,500 t of plastic removed yearly; the range corresponds to uncertainty in the surface concentration of plastics in the GPGP. Estimated cleanup times depends mainly on the number of booms that can be deployed in the GPGP without sacrificing collection efficiency. Self-powered cleanup may be a viable approach for removal of plastics from the ocean, and gaps in our understanding of GPGP characteristics should be addressed to reduce uncertainty.

A systematic review on garbage enzymes and their applications in environmental processes.

Understanding the new insight on conversion of organic waste into value-added products can improve the environmental activities driven by microorganisms and return the nutrients to environment and earth. Here, we comprehensively review the available knowledge on application of garbage enzyme (GE) for different environmental activities including waste activated sludge, composting process, landfill leachate treatment, soil remediation and wastewater treatment with special focus on their efficiency. To identify peer-reviewed studies published in English-language journals, a comprehensive search was performed across multiple electronic databases including Scopus, Web of Science, Pubmed, and Embase. The search was conducted systematically using relevant keywords. The eligible studies were analyzed to extract data and information pertaining to components of GE, fermentation process operational parameters, type of hydrolytic enzymes and improved environmental performance. The findings derived from this current review demonstrated that GE produced from the fruit and vegetable peels, molasses or brown sugar (carbon source), and water within fermentation process contain different hydrolytic enzymes in order to facilitate the organic waste degradation. Therefore, GE can be considered as a promising and efficient pathway in order to improve the environmental activities depended on microorganism including, composting, wastewater and leachate treatment and bioremediation process.

The key role of denitrification and dissimilatory nitrate reduction in nitrogen pollution along vertical landfill profiles from metagenomic perspective.

Landfill are persistent sources of nitrogen (N) pollution even in the decades after closure. However, the biological pathways of N-pollution, particularly N2O and NH4+, at different landfill depths have received little attention. In this study, metagenomic analysis was conducted on landfill refuse from vertical reservoir profiles in two closed landfills named XT and MT. NH4+ concentrations were found to be higher in deeper layers of MT, while greater potential for N2O emissions occurred in XT and the shallow layers of MT. Furthermore, the community structure and function of N-metabolizing microbes were more strongly defined by landfill depth than landfill type. Denitrification, involving abundant nirK and norB genes, was identified as the major pathway for N2O production in both XT and MT-shallow, while dissimilatory nitrate reduction with abundant nirBD genes was identified as the major pathway for NH4+ accumulation. Microbes of norB-type and nirBD-type were positively affected by NO3- in XT, whereas negatively affected by contents of organic material and moisture in MT-shallow. The mechanism by which nitrogen fixation, with abundant nifH genes, contributes to NH4+ accumulation in MT-deep should be further elucidated. These findings can provide a theoretical basis for governing scientific N-pollution control strategies throughout the entire landfill process.

Bad or worse? Applying critical theory to explore the impacts of Payatas dumpsite closure on the former waste pickers.

Numerous garbage dumpsites worldwide have been closed down to address the safety, health and environmental hazards facing waste pickers, such as potential landsides, diseases and pollution. As a result, the environment surrounding the (former) waste pickers may have been safer and cleaner. While the closure of garbage dumpsites may be an act of social justice to protect waste pickers, however, in some cases, the incomes and living standards of former waste pickers who continue to reside at these sites have been aggravated. Drawing on critical theory, and using observations and interviews, this case study examined the post-dumpsite-closure situation of Payatas in the Philippines. This study augments previous research on critical urban and regional studies through the presentation of a meta-critical theory by expanding, critiquing and reconceptualizing critical theory to address the problematic post-dumpsite situation created through the closure of the dumpsite.

Technical solutions for waste classification and management: A mini-review.

The massive growth of population coupled with urbanization over the years has created a significant challenge of increase in waste generation. India has achieved massive developmental growth in economic and social areas but still lacks a proper waste management system. The lack of knowledge about segregation of waste into different categories and proper disposal techniques in a country like India with an accelerated population growth is a critical issue. Since trash has different disposal techniques, according to its type, segregating waste through an automated process at the point of collection will streamline the process and result in effective waste management and utilization. The mini-review article evaluates the recent literature on technologies used for municipal waste segregation and management, with the motive of providing critical information for advancement in current research. This article reviews the use of various convolutional neural network architectures for waste classification and describes in detail as to why image processing methods are preferred over sensors for segregation into respective categories. It is also important to have an efficient waste monitoring and management system for proper disposal. A comprehensive mini-review was undertaken to understand internet of things-based models proposing efficient waste handling, from the perspective of reduced costs, collection time and optimized routes. The proposed systems were compared and evaluated based on the sensors used monitoring, microcontrollers and communication protocols such as Long Range, Global System for Mobile Communication, Zigbee and Wi-Fi, which are employed for the secure and efficient data transmission.

Sector arc routing-based spatial decision support system for waste collection in Brazil.

We present a sector arc routing problem-based spatial decision support system technology to develop tactical and operational plans and manage solid waste collection activities including household refuse collection and human and mechanical street sweeping. The proposed technology can also manage solid waste services through optimization (minimizing sector costs, distances and resources). The proposed technology is called optimized planning and integrated logistics management. It can be directly applied to Brazilian municipalities as it contains its major natural features. The system uses advanced technics from sector arc routing and sector scheduling, fleet and staff scheduling and daily plan management using mobile smartphone apps. The technology also allows for waste system inspections that are transparent to all participants in real time. We present the results of cases evaluated in the field for residential refuse collection and human and mechanical street sweeping in two Brazilian cities (Campo Grande and São Paulo). The plan implementations achieved from 12 to 28% actual fixed and variable cost savings for sectors (vehicles and workers) and routes (time and distances) for residential refuse collection and from 7 to 42% savings for human and mechanical street sweeping for the companies.

Life cycle environmental and economic comparison of thermal utilization of refuse derived fuel manufactured from landfilled waste or fresh waste.

This paper analyses environmental and economic performance of thermal utilization technologies of two different refuse derived fuel (RDF) manufactured from landfilled waste or fresh municipal waste, including incineration of landfilled RDF (I-LRDF), gasification of landfilled RDF (G-LRDF), replacement of partial coal by landfilled RDF for the cement industry (C-LRDF), incineration of municipal RDF (I-MRDF), and replacement of partial coal by municipal RDF for the cement industry (C-MRDF). The preference among the RDF utilization options is identified from the standpoints of various stakeholders by integrating the life cycle assessment (LCA) and techno-economic analysis (TEA) with the analytic hierarchy process (AHP) and technique for order preference by similarity to ideal solution (TOPSIS) approaches. RDF thermal utilization technologies bring an economic profit of $17.29∼$35.77 per ton of waste. Especially, I-LRDF has the worst effect on ecosystem quality and human health and can yield the greatest economic profit of $35.77 per ton of landfilled waste, while I-MRDF has the least impact on environment. In terms of the five RDF thermal utilization technologies, I-MRDF has the best comprehensive performance from the perspectives of different stakeholders. The improvement of the RDF thermal utilization efficiency is the most critical factor affecting the economic benefits for all cases.

Waste plastic resource recovery from landfilled refuse: A novel waterless cleaning method and its cost-benefit analysis.

The efficient classification and resource conversion of landfilled refuse can simultaneously realize the secondary pollution prevention and land replacement. This work aimed to investigate the waste plastic resource recovery from landfilled refuse via a novel waterless cleaning method. Composition analysis showed that the content of waste plastic from landfilled refuse had differences between different regions, and the specific weight content range was between 15-40%. Moreover, when the landfill time was less than 7 years, the high calorific value (>35 MJ/kg) and mechanical property (declining range <3%) of waste plastic were basically the same as those of the original waste plastic, indicating a high resource attribute. However, due to the high degree of pollution, it was difficult to directly make high-value utilization. Furthermore, a waterless device was designed for waste plastic cleaning, and 94% cleaning rate was obtained with the optimal conditions of the sand medium particle size of 4-14 mesh, stirring speed of 50 r/min, and the operation time of 45 min. The actual on-site pilot test was carried out under the best conditions, and the results showed that the cleaning rate of waste plastic could reach 90%. On the basis, cost-benefit analysis of different waste plastic recycling methods was carried out. Compared with the other four methods, direct extrusion molding after multi-effect cleaning had lower resource consumption (cost of 88.64 RMB), higher economic benefit (net income of 311.36 RMB), and was more in line with the characteristics of raw materials. This research can provide scientific basis and technical support for the cleaning and upgrading and resource utilization of plastic in refuse.

Efficiency of municipal packaging waste recovery chain and suitability of separated residual waste fractions for use in alternative fuels production.

Due to the sheer quantity and quality of material, packaging waste is separately collected by municipal waste management systems, with a primary goal of its use in material recovery. The residual waste, i.e. rejected waste in the separation process can be energy recovered. Both recovery options have specific input material quality requirements. Therefore, it is important to know the characteristics of individual waste streams. This research analysed the composition and morphological characteristics of separately collected packaging waste from municipal waste management system, residual (rejected) waste fractions after separation steps and produced refuse-derived fuel (RDF). The efficiency of primary and secondary (manual) waste separation, as well as of the RDF production step, are tracked. Results show that primary waste separation produces material with under 7% of contaminants and secondary manual waste separation efficiency ranges between 45% and 55%. Physico-chemical comparison of simulated RDF strongly coincides with analysed properties of RDF as a final product which indicates very high separation efficiency in the RDF production. From the energy recovery/conversion standpoint, this can be quantified through deviations in the lower heating value (LHV) and the effective H/C molar ratio between simulated and real RDF samples, which are on the level of 1.8% and 1.1% respectively. The following conclusion can be made from the estimated relation between changes in separation efficiency and RDF energy-related characteristics; the separation efficiency of individual components plays important role in alternative fuel production as chemical compositions directly influence suitability for high-quality liquid fuel production. Results of this analysis shed a light on the connection between aspirations to increase material recovery share and the suitability of produced residual waste for further recovery and valorisation. The material and energetic valorisation are competitors, and further evaluation should be done to understand the investments needed to increase valuable fractions of wastes separation that, in turn, could diminish the energetic value of residual fractions and, therefore, the economic viability of energy recovery facilities.

Pyrolysis and Gasification of a Real Refuse-Derived Fuel (RDF): The Potential Use of the Products under a Circular Economy Vision.

Refuse-Derived Fuels (RDFs) are segregated forms of wastes obtained by a combined mechanical-biological processing of municipal solid wastes (MSWs). The narrower characteristics, e.g., high calorific value (18-24 MJ/kg), low moisture content (3-6%) and high volatile (77-84%) and carbon (47-56%) contents, make RDFs more suitable than MSWs for thermochemical valorization purposes. As a matter of fact, EU regulations encourage the use of RDF as a source of energy in the frameworks of sustainability and the circular economy. Pyrolysis and gasification are promising thermochemical processes for RDF treatment, since, compared to incineration, they ensure an increase in energy recovery efficiency, a reduction of pollutant emissions and the production of value-added products as chemical platforms or fuels. Despite the growing interest towards RDFs as feedstock, the literature on the thermochemical treatment of RDFs under pyrolysis and gasification conditions still appears to be limited. In this work, results on pyrolysis and gasification tests on a real RDF are reported and coupled with a detailed characterization of the gaseous, condensable and solid products. Pyrolysis tests have been performed in a tubular reactor up to three different final temperatures (550, 650 and 750 °C) while an air gasification test at 850 °C has been performed in a fluidized bed reactor using sand as the bed material. The results of the two thermochemical processes are analyzed in terms of yield, characteristics and quality of the products to highlight how the two thermochemical conversion processes can be used to accomplish waste-to-materials and waste-to-energy targets. The RDF gasification process leads to the production of a syngas with a H2/CO ratio of 0.51 and a tar concentration of 3.15 g/m3.

Effects of operating parameters on co-gasification of coconut petioles and refuse-derived fuel.

Coconut agro-industry in the western region of Thailand generates a large amount of residues. This study investigated the energy production potential of discarded coconut petioles, with a focus on co-gasification with refuse-derived fuel (RDF). Gasification tests involving petioles, RDFs and their mixtures (25%, 50%, 75% or 100% by weight) were conducted in a laboratory-scale fixed bed reactor. Fuel samples of 5 g were gasified at 700°C-900°C for 60 minutes, using simulated air (79% N2 to 21% O2, by volume) as a gasifying agent. Gasification of petioles generated producer gas with lower heating values, estimated at 0.43-0.75 MJ Nm-3, while RDF produced 0.92-1.39 MJ Nm-3. Adding greater quantities of RDF to the fuel mixture resulted in an increase in the heating value of the producer gas and cold gas efficiency. The operating temperatures and gasifying-agent flow rates affected the efficiency of process differently, depending on the fuel composition. However, the maximum cold gas efficiency from both fuels was detected in tests conducted at 800°C. In co-gasification and pure refuse-derived-fuel tests, higher temperatures and gasifying-agent flow rates led to outputs with higher energy yields. Our findings suggested that co-gasification of petiole is a viable alternative waste-treatment technology for this region.

Degradation of refractory organic matter in the effluent from a semi-aerobic aged refuse biofilter-treated landfill leachate by a nano-Fe3O4 enhanced ozonation process.

In this study, the transformation and degradation mechanisms of refractory organic matter in biologically treated leachate from a semi-aerobic aged refuse biofilter (SAARB) in a nano-Fe3O4 enhanced ozonation process (nFe3O4-O3) were investigated in batch experiments. A continuous experiment then confirmed the effectiveness of the process for SAARB effluent treatment. In a batch experiment, the effects of influencing factors, including nFe3O4 dosage, O3 dosage and initial pH on the treatment performance of nFe3O4-O3 process, were comprehensively investigated. The results showed that when the nFe3O4 dosage = 6 g L-1, O3 dosage = 0.15 L minute-1 and initial pH = 7, the total organic carbon, absorbance at 254 nm and colour number removal efficiencies were 40.58%, 62.55% and 89.80%, respectively. In addition, most of the humic- and fulvic-like substances in the SAARB effluent were removed, and the condensation degree, aromaticity and humification degree of the organics were substantially reduced. The morphology and elemental valence state analysis showed that the nFe3O4 in the process was relatively stable and could form an nFe3O4-organic complex. Therefore, the probability of organics reacting with hydroxyl radical increased and the oxidation efficiency was enhanced. In the continuous experiment, both the O3 dosage and hydraulic retention time (HRT) were the key influencing factors. The treatment efficiency of the nFe3O4-O3 process was enhanced at a higher O3 dosage and longer HRT. The electrical energy consumption of the continuous nFe3O3-O3 process was calculated to be 17.72 kW h m-3 in SAARB effluent treatment. This study proved the feasibility of biologically treated landfill leachate treatment by the nFe3O3-O3 process.

Parvularcula mediterranea sp. nov., isolated from marine plastic debris from Zakynthos Island, Greece.

A Gram-negative, dark orange-pigmented, aerobic, non-spore-forming, coccoid-shaped bacterium designated as ZS-1/3T was isolated from a floating plastic litter (polypropylene straw) sample, collected from shallow seawater near the public beach of Laganas on Zakynthos island, Greece. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate is affiliated with the genus Parvularcula in the family Parvularculaceae. Its closest relatives are Parvularcula lutaonensis (98.09  %) and Parvularcula oceanus (95.89  %). The pH and temperature ranges for growth are pH 5-10 and 20-38 °C (optima, pH 7.0 and 28 °C). The predominant fatty acids are C18 : 1 ω7c (56.84  %), C16 : 0 (27.51  %), C18 : 0 (2.25  %) and C12 : 0 (1.42  %). The predominant respiratory quinone detected in strain ZS-1/3T is quinone-10 (Q10); the majority of detected polar lipids are glycolipid. The DNA G+C content is 62.5  mol%. Physiological and chemotaxonomic data further confirmed the distinctiveness of strain ZS-1/3T from other members of the genus Parvularcula. Thus, strain ZS-1/3T is considered to represent a novel species of the genus, for which the name Parvularcula mediterranea. sp. nov. is proposed. The type strain is ZS-1/3T (=NCAIM B 02654T=CCM 9032T).

Disposal practice and factors associated with unused medicines in Malaysia: a cross-sectional study.

BACKGROUND: The improper disposal of unused medicines is a worldwide concern because of its impact on the environment, economy, and health. This study aims to describe the disposal practice of unused medicine and identify factors associated with unused medicines in Malaysia. METHODS: This was a cross-sectional, face to face interview-based survey using a structured questionnaire. We used a convenience sampling method to recruit participants from Kuala Lumpur and Selangor in Malaysia. RESULTS: We interviewed 1184 participants, and the response rate was 96%. Out of the total respondents, 995 (84%) reported having unused medicines. About a quarter of respondents kept unused medicines in the cabinet, and another quarter disposed of them into the trash or toilet. Only half of the respondent who used medicines for chronic illnesses had unused medicines compared to about 90% of respondents who used medicines for acute illnesses. The main reason for having unused medicines among those who used medicines for chronic illness was non-adherence (69%, p <  0.05). Only 27% of these respondents returned unused medicines under the "Medicine Return Programme (MRP)". The other group who used medicines for acute illnesses had unused medicines because their health conditions improved. Thus, most of the unused medicines will eventually end up in household waste. A multivariate logistic regression analysis identified respondents who used medicines for acute illnesses as the strongest predictor of having unused medicines (Odds Ratio (OR) = 29.8; p <  0.001), followed by those who pay for their medicines (OR = 6.0; p < 0.001) and those who were willing to participate the Medicine Return Programme (OR = 2.5; p = 0.009). CONCLUSION: The prevalence of unused medicines and their improper disposal were high in Malaysia. Unused medicines are associated with people who use medicines for acute illnesses, pay for their medication, and are willing to participate in an MRP. Rationale prescription and optimal dispensing practice, together with a broader MRP facilities coverage, could reduce unused medicine possession.

To keep or not to keep? Sorting out leftovers from a refrigerator.

Most literature on food waste shows that food that ends up in the garbage can is often no longer considered as enjoyable, or even as edible. In this paper, we decided to focus on assessments of whether leftover food is still considered as worth eating, to provide a better understanding of the production of domestic food waste. We constructed a pluridisciplinary approach, combining sensory analysis and sociology. The first part was conducted in a test kitchen under controlled conditions: 50 participants had to sort out and decide to keep or to throw away different types of refrigerated leftovers. The second part used in-depth interviews with half of these participants (N = 25) to explore their food habits and perceptions and handling of leftovers at home. The first section of the paper presents the theoretical framework of the study, which is grounded in practice theory. Then we detail the methodology and the results. We show that sorting out leftovers is a process mobilizing embodied knowledge and resulting from domestic practices implemented to avoid waste, such as storing or reusing leftovers. In the discussion, we analyze the sorting of refrigerated food products as a compound practice, situated at the intersection of provisioning, cooking, meal organization, and judgment of taste (Warde, 2013). Using this theoretical framework enables us to understand the heterogeneity observed in the outcome of the sorting process as the result of its weak degree of regulation. The sorting out practice is thus consistent with different modes of engagement such as food waste prevention, health maintenance, or providing enjoyable family meals. We conclude by providing suggestions of policy recommendations regarding domestic refrigeration, food storage, and assessment practices.

"Waste not and stay at home" evidence of decreased food waste during the COVID-19 pandemic from the U.S. and Italy.

The COVID-19 pandemic has profoundly disrupted household food purchasing and preparation, including elements identified as important drivers of household food waste. The two main aims of this study were (1) to examine changes in food waste behaviors since the start of the COVID-19 pandemic in the U.S. and Italy; and (2) to investigate potential predictors of food waste behavior, including avoidance of supermarkets, increased home cooking, and increased role of health concerns in food choices. A sample of n = 478 (79% female) individuals from the U.S., mean (SD) age = 30.51 (10.85), and n = 476 individuals from Italy, (78% female), mean (SD) age = 33.84 (12.86), completed an online survey between April 8th and April 28th 2020. Just under half of respondents (49%) reported decreased food waste since the start of the pandemic. Rates were significantly higher among the U.S. sample (61.5%, n = 294) compared to the Italian sample (38%, n = 180). Controlling for the time since restrictions were introduced, age, gender, and perceived financial security, logistic regression revealed greater reduction in food waste since the beginning of the pandemic for U.S. individuals relative to participants from Italy (OR = 0.47, p < .001). In addition, increased importance of health concerns when making food choices (OR = 1.34, p < .005) as well as more frequent cooking (OR = 1.35, p < .001), and greater avoidance of supermarkets (OR = 1.15, p = .049) were associated with greater probability of less food waste. Scarcity and greater reliance on cooking may encourage individuals to reflect on food waste practices. Further research should explore how these factors may be targeted to reduce food waste beyond the pandemic.