Consumption Threshold Research Articles

The role of photovoltaic technology in achieving net zero energy target in residential buildings

The construction sector plays a pivotal role in reducing carbon emissions, facilitating the transition to renewable energy and promoting sustainable development. In the European Union, where decarbonization strategies are currently proving most incisive, legislative measures such as the Energy Performance of Buildings Directive (EPBD) have catalyzed a marked increase in the prevalence of energy-efficient buildings. In terms of decarbonization, such efforts can be achieved by massively applying Renewable Energy Sources (RES) both in new buildings as well as in existing ones, which represent the majority of the EU building stock. For such reasons, Building-Integrated/Applied Photovoltaic (BIPV/BAPV) systems offer a promising avenue for providing clean energy to the building sector. Nonetheless, despite their potential, the practical implementation of these systems on buildings faces feasibility constraints, mainly due to the limitation of the available installation surface.In such a framework, this study conducts a comprehensive evaluation of BIPV/BAPV installations potential to fulfill the electricity needs of residential buildings (i.e. achieve the net zero energy target), with a particular focus on multi-family structures within the European contest. A reference high-performance building, already assessed by the authors and therefore very well documented, was used as a test bed through detailed dynamic energy simulations. According to obtained results, the net zero energy target can be achieved for energy-efficient buildings with up to 3 and 5 storeys, in Nordic and Mediterranean climatic conditions, respectively. Assuming instead reference maximum consumption thresholds (resulting in higher energy consumption), achievable results are more restrictive, since zero-energy buildings are limited to a maximum of less than 2 storeys in Nordic climates and 3 in Mediterranean climates.In this particular historical period, the outlined results take on considerable relevance, as the highlighted feasibility limitations could jeopardise the implementation of zero emission targets, but they can also be used to properly orient energy policies under development.

Optimizing vertical farm cultivation of Cichorium spinosum L.: White Light's influence and nutrition management

The objective of this study was to examine the integration of a wild leafy vegetable, Cichorium spinosum L., in vertical farms. This research comprises two experiments focusing on different “white” light products and nutrient solutions. During both experiments, the temperature varied between 25 and 28 °C, relative humidity ranged from 50 to 70 %, carbon dioxide was at 450 ppm, and light intensity was set at 300 μmol m−2 s−1 respectively. In the lighting experiment, the three spectra used had the commercial names Neutral, Full and a SunLike™, and their spectral composition (blue:green:red:far-red) were 14:32:43:10, 16:36:40:8, and 21:34:36:7 respectively. The photoperiod was set to 12 h and the plant density was 50 plants m−2. Results showed no significant impact on agronomical parameters and leaf anatomy. The stomatal length and width decreased as the red:blue ratio of the light sources decreased, being greater in the Neutral treatment (red:blue ratio of 3.1) compared to the Full and SunLike™ (red:blue ratios of 2.5 and 1.7 respectively). Based on these results the preferable “white light” product was the one with the highest efficiency and lowest market price at the time of the experiment. In the nutrient solution experiment, the agronomical and nutritional attributes of stamnagathi plants supplied with a control nutrient solution, “N10-Fe15” were compared to plants cultivated under limited nitrogen, “N4-Fe15” and elevated iron, “N10-Fe48”, EC was 1.5 ds m−1, and pH was 5.6–6.5. The experiment simulated commercial practices by increasing the photoperiod to 15 h and plant density to 100 plants per square meter. The results did not demonstrate significant effect of the nutrient solution differences on the agronomical characteristics except from a decrease in total Kjeldahl nitrogen under limited nitrogen conditions. Notably, leaf tissue phosphorus content increased under elevated iron conditions. The nitrate content remained within safe for consumption thresholds for all treatments. Based on these results, stamnagathi can be integrated in vertical farms under limited nitrogen conditions. Stamnagathi's resilience to elevated iron in the nutrient solution demonstrated its potential for future biofortification experiments.

An IoT Based Smart Watt Metering for Energy Management System

This paper presents the analysis of IoT based Smart Watt Metering for Energy Management System. The proposed system, "An IoT Based Smart Watt Metering for Energy Management System," introduces a cost-effective and energy-efficient solution for monitoring and managing power consumption of electrical appliances. Utilizing non-intrusive current and voltage sensors, the system measures key electrical parameters such as current, voltage, and power factor in real-time. The ESP32 microcontroller, known for its low power consumption, processes and transmits this data via Wi-Fi to a central server or cloud platform, enabling remote access through a user-friendly web or mobile application. The interface allows users to visualize power usage trends, set consumption thresholds, and receive alerts for abnormal usage. Additionally, the system incorporates data logging capabilities, storing historical consumption data for long-term analysis and energy-saving decision-making. This innovative approach provides a detailed and accessible means for users to optimize energy usage and reduce costs, contributing to more efficient energy management amidst the global energy crisis

Carbon Pricing, Carbon Dividends and Cooperation: Experimental Evidence

We investigated whether carbon taxes with and without carbon dividends improve cooperative behavior to mitigate simulated climate change. We implemented a randomized controlled trial on a large sample of the U.S. general population (N=2,116). Played in real-time in groups of four, we tested three carbon-pricing treatments and a baseline condition within a modified threshold public goods game of loss avoidance. We found that a carbon tax coupled with carbon dividends reduces carbon-emitting group consumption relative to a baseline condition with no tax, and relative to a carbon tax only. A carbon tax coupled with carbon dividends paid out to below-average polluters (asymmetric dividend) worked best, with 94% of groups remaining below a critical consumption (emission) threshold. We also found that experiencing the asymmetric dividend condition positively affected perceptions of carbon pricing with carbon dividends.

Mercury biomagnification in the food chain of a piscivorous turtle species (Testudines: Chelidae: Chelus fimbriata) in the Central Amazon, Brazil.

Due to their natural history and ecological attributes, turtles are excellent organisms for studies of heavy metal contamination. Turtles have a large geographical distribution, occupy different aquatic habitats, and occupy various trophic levels. The present study investigated mercury bioaccumulation in the carnivorous chelonian Chelus fimbriata (Matamata turtle) and Hg biomagnification in relation to its aquatic food chain in the middle Rio Negro, AM-Brazil. Tissue samples of muscle, carapace and claws were collected from 26 C. fimbriata individuals, as well as collections of autotrophic energy sources found in the turtle's aquatic habitat area. The samples were collected in February-March/2014 and analyzed for THg concentrations and carbon (δ13C) and nitrogen (δ15N) stable isotopes. The highest THg levels were found in claws (3780 ng.g-1), carapace (3622 ng.g-1) and muscle (403 ng.g-1), which were found to be significantly different [F(2.73) = 49.02 p < 0.01]. However, THg concentrations in muscle tissue were below the consumption threshold indicated by the WHO and Brazilian Health Ministry. The average δ13C and δ15N values in Matamata samples were -31.7‰ and 11.9‰, respectively. The principal energy source sustaining the food chain of C. fimbriata was found to be terrestrial shrubs, with smaller contributions from emergent aquatic herbaceous plants and algae, while δ15N values showed its trophic position to be two levels above the autotrophic energy sources. There was a positive correlation between THg and turtle size, while a significant relationship was found between THg and δ15N, showing strong biomagnification in the food chain of C. fimbriata: y = 0.21x + 0.46; r2 = 0.45; p < 0.001, for which the slope presented a value of 0.21.

Fish Tissue Mercury in Lakes and the Moderating Effects of Selenium

Fish mercury concentrations result in fish consumption advisories. However, selenium : mercury molar ratios &gt;1 are protective to wildlife and humans. Therefore, we sampled total selenium (TSe) and total mercury (THg) concentrations and molar ratios in sport fish from 50 Idaho (ID) lakes &gt;20 ha and 67 northeastern USA (NE) lakes &gt;1 ha. Sample lakes were selected at random, to obtain unbiased estimates of mean fish tissue levels, with known confidence limits, for target populations of 95 ID lakes &gt;20 ha in surface area and 12,557 NE lakes &gt;1 ha. Bass and salmonids presented the greatest potential mercury toxicity risk to consumers based on their higher mercury content, desirability as game fish, and widespread distributions. Fish tissue THg exceeded safe consumption criteria in an estimated 20–80% of the lakes in the two regions and TSe exceeded safe consumption thresholds in an estimated 0–20% of the lakes in the two regions. However, the Se : Hg molar ratio was &gt;1 in an estimated 90–97% of fish tested from NE and ID lakes. Therefore, we concluded that Se levels in these systems are usually sufficient to limit disruption of selenoprotein activities by Hg, and that fish consumption advisories based on Hg alone are unnecessarily restrictive.

Long-term effects of alcohol consumption on anxiety in adults: A systematic review

ObjectiveDespite the high prevalence and comorbidity of alcohol consumption and anxiety, it is unclear whether alcohol consumption influences long-term anxiety. This study aimed to systematically review the literature on the long-term longitudinal effects of alcohol consumption on anxiety in adults. MethodsEMBASE, PsychInfo, Medline, and Web of Science databases were systematically searched from inception to April 12th, 2024. Articles analysing the relationship between alcohol consumption and anxiety symptoms or anxiety disorder diagnosis at least three-months later in adults were eligible. Articles were screened and extracted by two independent reviewers with study quality assessed using the Mixed Methods Appraisal Tool. ResultsFrom 884 records, eight studies of mixed quality met inclusion criteria. One study using a sample representative of the USA population found low volume consumption was associated with lower long-term anxiety. All other studies used a convenience sample or a specific medical population sample. The significance and direction of the relationship between alcohol consumption and long-term anxiety in these studies varied, likely due to differences in alcohol consumption thresholds used and populations studied. ConclusionsA paucity of research on the longitudinal effects of alcohol consumption on anxiety was found, highlighting a significant gap in the research literature. Furthermore, existing research, primarily focussed on clinical subpopulations, has yielded mixed results. Further research is needed to explore the longitudinal dose dependent impact of alcohol consumption on anxiety using samples representative of national populations.

Navigating the Nomenclature of Liver Steatosis: Transitioning from NAFLD to MAFLD and MASLD - Understanding Affinities and Differences

The escalating prevalence of non-alcoholic fatty liver disease (NAFLD) represents a significant challenge to public health, with an increasing impact observed across various demographics. This review delivers a comprehensive evaluation of the evolving terminology in steatotic liver disease (SLD), documenting the transition from NAFLD to metabolic dysfunction-associated fatty liver disease (MAFLD), and progressing to the latest terms, metabolic dysfunction-associated fatty liver disease (MASLD) and MASLD with increased alcohol intake (MetALD). We conducted a comprehensive review of literature discussing the benefits and drawbacks of these nomenclatural changes. Clinical evidence supporting MASLD and MetALD, including the implications of alcohol consumption thresholds on disease classification and outcomes, was analyzed. The “MAFLD” and “MASLD” labels align with the pathophysiology of metabolic diseases, afford a positive disease connotation, and facilitate the identification of more severe diseases, such as significant fibrosis or advanced liver disease. However, the MAFLD criteria may underdiagnose lean, non-overweight, or non-obese individuals with MAFLD. The review underscores the understanding of liver diseases linked to metabolic dysfunction and alcohol use. The shift in terminology marks progress towards a clinical diagnosis that reflects underlying pathophysiology. However, additional studies are necessary to assess the longterm effects of these changes and their efficacy in enhancing patient care and health outcomes.

Unravelling the complex interplay between antibiotic consumption and adaptive changes in methicillin-resistant Staphylococcus aureus.

This study aims to elucidate the genomic dynamics driving the emergence of antimicrobial resistance (AMR), with a specific focus on the interplay between AMR and antimicrobial usage. We conducted a comprehensive analysis using a ST239 methicillin-resistant Staphylococcus aureus (MRSA) dataset over a continuous 12-year period from a single hospital. Genomic analyses were performed tracking the changes in MRSA populations, particularly the emergence of reduced vancomycin susceptibility, and assessing the impact of glycopeptide use on these emergence events. Our findings reveal a significant correlation between hospital glycopeptide usage and the selection of MRSA strains with reduced vancomycin susceptibility. Genomic analyses provided insights into the molecular mechanisms driving resistance emergence, including the slowing of the molecular clock rate in response to heightened antimicrobial consumption. In conclusion, this study the highlights the complex dynamics between AMR and antimicrobial use at the hospital level. The observed correlation between antimicrobial consumption and the development of less susceptible MRSA strains underscores the importance of antimicrobial stewardship programmes and the establishment of optimal consumption thresholds for mitigating AMR effectively.

Accumulation of total mercury in deep-sea sediments and biota across a bathymetric gradient in the Southeastern Mediterranean Sea

This study explores the accumulation of total mercury (THg) in deep-sea sediments and demersal megafauna of the ultra-oligotrophic Southeastern Mediterranean Sea (SEMS) across bathymetric gradients in the range 35–1900 m, sampled in seven cruises during 2013, 2017–2021, and 2023. Measurements of THg were conducted in surficial (0.0–0.5 cm) and subsurface (9.0–10 cm) sediments, demersal sharks, demersal teleost fish, and benthic crustaceans. Sedimentary organic carbon and biota δ13C and δ15N values were determined to explore possible foraging habitats and dietary sources of THg. The results exhibit an increasing trend of THg in surficial sediments with increasing bottom depth, while in the subsurface, pre-industrial sediments, THg remains lower, slightly increasing with depth. Having no major terrestrial point sources in this area, this increasing trend of THg in surficial sediments across bathymetric gradients is controlled by atmospheric mercury deposition, scavenged by the biological pump, and by lateral transport of particulate Hg in winnowed fine particles from the shelf. Similarly, the THg in benthic crustaceans and demersal fish ranged between 0.02 and 2.71 μg g−1 wet weight (0.06 and 10.8 μg g−1 dry weight) and increased with muscle δ13C as a function of distance offshore, while presenting a low THg-δ15N bio-magnification power. Our results suggest that foraging habitats, longevity, and species-specific depth distribution control their muscle THg bioaccumulation. Despite this complexity, the pooling of THg in megafauna into specific deep zones reflected the trend of increasing anthropogenic THg across bathymetric gradients. Furthermore, many of the biota measurements exceeded safe consumption thresholds for Hg and therefore, should be considered carefully in the development and regulation of deep-sea trawling in this region.

TEKSTİL ENDÜSTRİSİNDE DERİN ÖĞRENME KULLANARAK AŞIRI ELEKTRİK TÜKETİMİNİN ÖNLENMESİNE YÖNELİK BİR VAKA ÇALIŞMASI

Resources are the most critical input in the manufacturing industry therefore, resource consumption is an essential issue to be minimized. On the other hand, consumption depends on several parameters thus, it is difficult to estimate. Recently, Machine Learning (ML) and Deep Learning (DL) are powerful Artificial Intelligence (AI) subdomains for future prediction in any area. In this paper, a DL-supported electricity prediction method is designed for the textile industry as a case study in order to prevent resource over-consumption while the machines are in the standby state. This method provides dynamic consumption thresholds of electricity consumption by sliding window technique based Long-Short Term Memory (LSTM) model that helps the machines to interrupt manufacturing in their decision. These calculated thresholds are also compared with the results of Recurrent Neural Networks (RNN) and Gated Recurrent Units (GRU) as the other DL methods and Automated Regressive Integrated Moving Average (ARIMA) as a traditional method and then the results have been analyzed how close they are to real-time electricity consumption data at standby. According to the results, the LSTM model successfully predicts electricity consumption levels, sends an interrupt signal to Programmable Logic Controller (PLC) unit when the consumption levels reach the threshold and therefore prevents resource over-consumption.

Assessment of persistent organic pollutants in killer whales (Orcinus orca) of the Canadian Arctic: Implications for subsistence consumption and conservation strategies

Killer whales (Orcinus orca) historically restricted to certain Arctic regions due to extensive sea ice have recently been documented farther north and for longer durations in the Canadian Arctic. These apex predators accumulate high levels of persistent organic pollutants (POPs). The objective of this study was to evaluate the concentrations and profiles of POPs in killer whales of the Canadian Arctic, thus determining potential risks for Inuit communities if consumed. Biopsies were collected from 33 killer whales across areas of the Canadian Arctic between 2009 and 2021. Significant variability in POP concentrations was observed among whales. The cumulative POP concentrations ranged from 12 to >2270 mg/kg lw, representing ∼200-fold increase from the least to the most contaminated individual. The rank order of concentrations of the top five contaminant classes was ∑DDT, ∑PCB, ∑CHL, ∑Toxaphene, and Dieldrin. Several emerging Arctic contaminants were detected, including chlorpyrifos, endosulfan, pentachloroanisole, and polychlorinated naphthalenes, although at relatively lower concentrations than legacy POPs. Considering the elevated blubber POP levels in killer whales, recommended daily consumption thresholds, established based on human tolerable daily intake (TDI) values, were notably restricted for ∑PCB (<0.14 g), ∑DDT (<6.9 g), ∑CHL (<13 g), dieldrin (<8 g) and heptachlor epoxide (<5 g). Killer whales in the Canadian Arctic exhibited higher POP concentrations than other commonly hunted species such as polar bears, ringed seals, and Arctic char. We acknowledge that a more holistic risk assessment of diet is required to assess the cumulative impacts of contaminant mixtures as well as nutritional quality of tissues commonly consumed by northern communities.

Defining a Dichotomous Indicator for Population-Level Assessment of Dietary Diversity Among Pregnant Adolescent Girls and Women: A Secondary Analysis of Quantitative 24-h Recalls from Rural Settings in Bangladesh, Burkina Faso, India, and Nepal

BackgroundThe Minimum Dietary Diversity for Women of Reproductive Age (MDD-W) indicator was validated as a proxy of micronutrient adequacy among nonpregnant women in low- and middle-income countries (LMICs). At that time, indeed, there was insufficient data to validate the indicator among pregnant women, who face higher micronutrient requirements. ObjectiveThis study aimed to validate a minimum food group consumption threshold, out of the 10 food groups used to construct MDD-W, to be used as a population-level indicator of higher micronutrient adequacy among pregnant women aged 15–49 y in LMICs. MethodsWe used secondary quantitative 24-h recall data from 6 surveys in 4 LMICs (Bangladesh, Burkina Faso, India, and Nepal, total n = 4909). We computed the 10-food group Women's Dietary Diversity Score (WDDS-10) and calculated the mean probability of adequacy (MPA) of 11 micronutrients. Linear regression models were fitted to assess the associations between WDDS-10 and MPA. Sensitivity, specificity, and proportion of individuals correctly classified were used to assess the performance of MDD-W in predicting an MPA of >0.60. ResultsIn the pooled sample, median values (interquartile range) of WDDS-10 and MPA were 3 (1) and 0.20 (0.34), respectively, whereas the proportion of pregnant women with an MPA of >0.60 was 9.6%. The WDDS-10 was significantly positively associated with MPA in each survey. Although the acceptable food group consumption threshold varied between 4 and 6 food groups across surveys, the threshold of 5 showed the highest performance in the pooled sample with good sensitivity (62%), very good specificity (81%), and percentage of correctly classified individuals (79%). ConclusionsThe WDDS-10 is a good predictor of dietary micronutrient adequacy among pregnant women aged 15–49 y in LMICs. Moreover, the threshold of 5 or more food groups for the MDD-W indicator may be extended to all women of reproductive age, regardless of their physiologic status.

Organohalogenated contaminants in multiple life stages of the Pacific lamprey (Entosphenus tridentatus), Oregon, USA

Pacific lamprey (Entosphenus tridentatus) are ecologically and culturally important anadromous animals native to the West Coast of the United States. Pacific lamprey populations are in decline, and contaminants may be a contributing factor. Between 2017 and 2021, three life stages of Pacific lamprey and collocated sediment samples were collected in Oregon (larval lamprey, sediment, and returning adult lamprey) and off the coast of Oregon and Washington (ocean juvenile lamprey). Tissue and sediment samples were analyzed for 56 organohalogenated compounds that included legacy pesticides, current use pesticides, polybrominated diphenyl ether congeners, and polychlorinated biphenyl congeners. Organohalogenated compounds were detected in all three Pacific lamprey life stages. The organohalogenated compounds detected in collocated sediment and larval lamprey samples were generally dissimilar, and compounds detected in larval lamprey indicate potential point sources along the rivers. Ocean-caught juvenile lamprey had significantly higher lipid contents than returning adult lamprey, but lipid content and concentrations of select compounds were not strongly correlated. Concentrations of select compounds detected in both ocean juvenile and returning adult lamprey were either not significantly different or were higher in returning adult lamprey. Concentrations of some compounds in returning adult lamprey—which are consumed by Indigenous peoples—exceeded state and national human health consumption thresholds. Collaboration among Tribes and public-sector agencies helped make this study successful.

Mode Adaptive Secure UAV Relay Transmissions

Unmanned aerial vehicles (UAV) can enhance wireless transmission security by improving the secrecy rate through relaying the legitimate transmission and injecting artificial noise to the eavesdroppers. However, due to the inherent mechanical energy consumption and the long-range signal propagation pathloss, the traditional cruising and hovering UAV relay modes are deficient in energy utilization and secrecy rate, respectively. Modeling of the secrecy energy efficiency with respect to UAV mode adaptation is limited in the literature and deserves further investigation. Therefore, in this paper, we propose a secrecy rate-energy efficient UAV relay mode adaptation scheme for secure wireless communications scenarios where the eavesdropping locations are known, i.e., the eavesdropper is a hijacked internal legitimate node. In this secure system, the UAV cooperatively assists the legitimate transmissions and injects artificial interference to the eavesdropper. We investigate optimum UAV placement and relay period planning for the hovering and the cruising relay modes, respectively. By modeling the UAV modes transfer and maximizing the secrecy energy efficiency, the optimum mode adaptation ratios are obtained under both the secrecy rate-prioritized and the energy-saving criteria. In addition, the proposed UAV relay mode adaptation mechanism is further studied for each UAV task division, to adapt to the dynamic channel variations and enhance the security. Our theoretical analysis shows that the mode adaptation ratio is determined by the secrecy rate-energy gain between the cruising and the hovering modes, and by the energy consumption threshold of the UAV relays. Our numerical results demonstrate that the proposed scheme achieves higher secrecy energy efficiency than the traditional schemes.

Contaminant Risk and Social Vulnerability Associated with Crustacean Shellfish Harvest in the Highly Urbanized San Diego Bay, USA

People in coastal cities around the world harvest seafood from local bays despite well-documented health risks. In cities such as San Diego, California, USA, much information about contaminants and human consumption patterns exists for finfish but is largely lacking for shellfish. This study sought to better understand shellfish contamination risks and human vulnerability to inform management and advisories. In summer 2018 and winter 2019, we sampled crustaceans for chemical contaminants and anthropogenic debris and throughout the year surveyed people harvesting from three public fishing piers around San Diego Bay. Of the emerging contaminants found, pyrethroids, benzylbutyl phthalate, PFOS and anthropogenic debris were in differing concentrations in the muscle and viscera of the California spiny lobster and two species of crabs. Combined with previous metal and organic contaminant data from the lobster, 22 contaminants were detected with 5 exceeding consumption thresholds and 8 lacking defined thresholds. California spiny lobster was the main crustacean harvested from piers, attracting shellfishers from a range of ages, incomes, home locations and self-identified racial/ethnic groups. Consumption preferences (e.g., muscle or viscera) were non-discriminant, making lobster contamination a community-wide risk. More monitoring of emerging contaminants and different shellfish species (and tissues) of interest is recommended to capture the spatial and temporal dynamics of health risks, especially because the use of bivalves as sentinels may not reveal the same risks (e.g., PFAS, phosphate flame retardants).

Integration of Advanced Metering Infrastructure for Mini-Grid Solar PV Systems in Off-Grid Rural Communities (SoAMIRural)

Solar energy is considered a promising source of power generation in sub-Saharan Africa due to the high sunshine in these areas. Deploying decentralised solar-powered mini-grid systems to provide access to electricity in rural areas is fraught with difficulties in accurately predicting consumption, automatic monitoring, and operation sustainability to support the socio-economic conditions of rural communities. This study proposed SoAMIRural, which integrates solar PV mini-grid and advanced metering infrastructure for rural communities. SoAMIRural was implemented and tested for a case study community in Ghana. Solar PV Selection Equation Matrix (SPSEM) and Sample Size Equation (SSE) were used to determine the sustainable demand generation capacity of 24 kVA. Load estimations and need assessments were conducted to ascertain the rural community’s electric load and priority needs. SoAMIRural was evaluated with an error margin of 5%, resulting in 95% accuracy in energy consumption threshold management and monitoring to ensure energy conservation and sustainability of the mini-grid system. This study maps out a conceptual framework for a smart solar PV mini-grid system for rural communities and its advantages in realising SDG 7 in Ghana by 2030.

Understanding drivers of mercury in lake trout (Salvelinus namaycush), a top-predator fish in southwest Alaska's parklands

Mercury (Hg) is a widespread element and persistent pollutant, harmful to fish, wildlife, and humans in its organic, methylated form. The risk of Hg contamination is driven by factors that regulate Hg loading, methylation, bioaccumulation, and biomagnification. In remote locations, with infrequent access and limited data, understanding the relative importance of these factors can pose a challenge. Here, we assessed Hg concentrations in an apex predator fish species, lake trout (Salvelinus namaycush), collected from 14 lakes spanning two National Parks in southwest Alaska, U.S.A. We then examined factors associated with the variation in fish Hg concentrations using a Bayesian hierarchical model. We found that total Hg concentrations in water were consistently low among lakes (0.11–0.50 ng L−1). Conversely, total Hg concentrations in lake trout spanned a thirty-fold range (101–3046 ng g−1 dry weight), with median values at 7 lakes exceeding Alaska's human consumption threshold. Model results showed that fish age and, to a lesser extent, body condition best explained variation in Hg concentration among fish within a lake, with Hg elevated in older, thinner lake trout. Other factors, including plankton methyl Hg content, fish species richness, volcano proximity, and glacier loss, best explained variation in lake trout Hg concentration among lakes. Collectively, these results provide evidence that multiple, hierarchically nested factors control fish Hg levels in these lakes.

Food Freshness Measurements and Product Distinguishing by a Portable Electronic Nose Based on Organic Field-Effect Transistors.

Determination of food freshness, which is the most ancient role of the human sense of smell, is still a challenge for compact and inexpensive electronic nose devices. Fast, sensitive, and reusable sensors are long-awaited in the food industry to replace slow, labor-intensive, and expensive bacteriological methods. In this work, we present microbiological verification of a novel approach to food quality monitoring and spoilage detection using an electronic nose based on organic field-effect transistors (OFETs) and its application for distinguishing products. The compact device presented is able to detect spoilage-related gases as early as at the 4 × 104 CFU g-1 bacteria count level, which is 2 orders of magnitude below the safe consumption threshold. Cross-selective sensor array based on OFETs with metalloporphyrin receptors were made on a single substrate using solution processing leading to a low production cost. Moreover, machine learning methods applied to the sensor array response allowed us to compare spoilage profiles and separate them by the type of food: pork, chicken, fish, or milk. The approach presented can be used to monitor food spoilage and distinguish different products with an affordable and portable device.

Saving constraints, inequality, and the credit market response to fiscal stimulus

We document substantial heterogeneity in the interest rate response to fiscal stimulus (IRRF) across OECD economies. The IRRF is negative in half of the OECD countries, and it declines with income inequality. To interpret this evidence we develop a model in which moderately-low-income households take on debt to maintain a consumption threshold (effectively a saving constraint). Now burdened with debt, these households use additional income to deleverage. In more unequal economies with more saving-constrained households, increases in government spending tighten credit conditions less (relax credit conditions more), leading to smaller increases (larger declines) in the interest rate.