All-Loop Four-Point Aharony-Bergman-Jafferis-Maldacena Amplitudes from Dimensional Reduction of the Amplituhedron.

We define a new geometry obtained from the all-loop amplituhedron in N=4 SYM by reducing its four-dimensional external and loop momenta to three dimensions. Focusing on the simplest four-point case, we provide strong evidence that the canonical form of this "reduced amplituhedron" gives the all-loop integrand of the Aharony-Bergman-Jafferis-Maldacena four-point amplitude. In addition to various all-loop cuts manifested by the geometry, we present explicitly new results for the integrand up to five loops, which are much simpler than results in N=4 SYM. One of the reasons for such all-loop simplifications is that only a very small fraction of the so-called negative geometries survives the dimensional reduction, which corresponds to bipartite graphs. Our results suggest an unexpected relation between four-point amplitudes in these two theories.

Grassland productivity and carbon sequestration in Mongolian grasslands: The underlying mechanisms and nomadic implications.

BACKGROUND: Quantifying carbon (C) dioxide exchanges between ecosystems and the atmosphere and the underlying mechanism of biophysical regulations under similar environmental conditions is critical for an accurate understanding of C budgets and ecosystem functions. METHODS: For the first time, a cluster of four eddy covariance towers were set up to answer how C fluxes shift among four dominant ecosystems in Mongolia - meadow steppe (MDW), typical steppe (TPL), dry typical steppe (DRT) and shrubland (SHB) during two growing seasons (2014 and 2015). RESULTS: Large variations were observed for the annual net ecosystem exchange (NEE) from 59 to 193gCm-2, though all four sites acted as a C source. During the two growing seasons, MDW acted as a C sink, TPL and DRT were C neutral, while SHB acted as a C source. MDW to SHB and TPL conversions resulted in a 2.6- and 2.2-fold increase in C release, respectively, whereas the TPL to SHB conversion resulted in a 1.1-fold increase at the annual scale. C assimilation was higher at MDW than those at the other three ecosystems due to its greater C assimilation ability and longer C assimilation times during the day and growing period. On the other hand, C release was highest at SHB due to significantly lower photosynthetic production and relatively higher ecosystem respiration (ER). A stepwise multiple regression analysis showed that the seasonal variations in NEE, ER and gross ecosystem production (GEP) were controlled by air temperature at MDW, while they were controlled mainly by soil moisture at TPL, DRT and SHB. When air temperature increased, the NEE at MDW and TPL changed more dramatically than at DRT and SHB, suggesting not only a stronger C release ability but also a higher temperature sensitivity at MDW and TPL. CONCLUSIONS: The ongoing and predicted global changes in Mongolia likely impact the C exchange at MDW and TPL more than at DRT and SHB in Mongolia. Our results suggest that, with increasing drought and vegetation type succession, a clear trend for greater CO2 emissions may result in further global warming in the future. This study implies that diverse grassland ecosystems will respond differently to climate change in the future and can be seen as nature-based solutions (NBS) supporting climate change adaptation and mitigation strategies.

Income Inequality, Economic Complexity, and Renewable Energy Impacts in Controlling Consumption-Based Carbon Emissions.

Although many studies have been conducted on the role of renewable energy in the environment, literature has ignored the potential role of socioeconomic indicators in renewable energy and pollution nexus. Also, critical questions arose with the critical factors, such as income inequality and economic complexity, have not been answered properly. This study explores the nexus between income inequality, economic complexity, renewable energy consumption, GDP per capita, and pollution and thus aims to reach efficient policy strategies by revealing empirical evidence. The study follows an environmental impact model structure and conducts the panel-corrected standard errors and fixed effect regression. BRICS countries (Brazil, Russia, India, China, and South Africa) are selected to conduct our research. Annual data covering the period 1990-2017 for the sample countries are employed. Consumption-based carbon dioxide emissions as an indicator of environmental pollution are used since income inequality makes more sense in terms of the consumption side of an economy and is more related to consumers rather than the production sector. The obtained results reveal that income inequality has a positive and significant impact on consumption-based carbon dioxide emissions. However, GDP per capita, renewable energy, and economic complexity reduce pollution. It is also observed that the interaction term of inequality and renewable energy decreases emissions. Findings confirm that socioeconomic indicators, such as economic complexity and income inequality with the interaction of renewable energy, are crucial factors in reducing emissions and designing a greener future.

The greenhouse gas emissions from meat sheep production contribute double of household consumption in a Eurasian meadow steppe.

With the rapid development of the economy, household activities have emerged as an important source of greenhouse gas (GHG) emissions, making them a crucial focal point for research in the pursuit of sustainable development and carbon emission reduction. Hulunber, as a typical steppe region in eastern Eurasia, is representative of studying the GHG emissions from household ranches, which are the basic production units in this region. In this paper, based on survey data of 2018 and 2019, we quantified and assessed GHG emissions from household ranches by combining life cycle assessment (LCA) and structural equation modeling (SEM) approaches, with LCA to define household ranches system boundary and SEM to determine the key driving factors of emissions. The results showed that GHG emissions of meat sheep live weight was 23.54 kg CO2-eq/kg. The major contributor to household GHG emissions was enteric methane (55.23 %), followed by coal use (20.80 %) and manure management systems (9.16 %), and other contributing factors (14.81 %). The SEM results indicated that the GHG emissions from household ranches were derived primarily by economic level, while the economic level was significantly affected by income. This study also found a significant positive and linear correlation between household GHG emissions and the number of meat sheep (R2 = 0.89, P < 0.001). The GHG emissions from meat sheep production (67.52 %) were double times greater than household livelihood consumption (32.48 %). These findings emphasized the importance of reducing emissions from meat sheep production and adjusting the energy mix of household livelihood, contributing to the establishment of a low-carbon household livelihood operation.

Agreements between GLIM using left calf circumference as criterion for reduced muscle mass and PG-SGA, and GLIM using ASMI for the diagnosis of malnutrition in gastric cancer patients.

OBJECTIVE: this study aimed to explore the agreements between the Global Leadership Initiative on Malnutrition (GLIM) using left calf circumference (CC) as criterion for reduced muscle mass and the Patient-Generated Subjective Global Assessment (PG-SGA), or GLIM using appendicular skeletal muscle index (ASMI) for the diagnosis of malnutrition in gastric cancer patients. METHODS: the Nutritional Risk Screening 2002 (NRS 2002) was used as nutritional risk screening. PG-SGA and GLIM were applied for malnutrition diagnosis. Agreements were evaluated by Kappa, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and area under the curve (AUC). RESULTS: a total of 405 gastric cancer patients were included. The values of Kappa, sensitivity, specificity, PPV, NPV, accuracy and AUC were 0.463, 67.9 %, 87.3 %, 92.9 %, 52.8 %, 73.6 % and 0.776, and 0.496, 76.7 %, 78.0 %, 89.4 %, 57.9 %, 77.0 % and 0.773, respectively, between GLIM using CC with or without NRS 2002 and PG-SGA. All values of agreement were higher than 0.800 or 80.0 % between GLIM using left CC and GLIM using ASMI. CONCLUSION: the agreements were both acceptable between GLIM using left CC and PG-SGA, and GLIM using ASMI. Left calf circumference can be one of the credible references indicating a reduced muscle mass in patients with gastric cancer.

Financial compensation for natural forest logging ban: Standard calculation based on willingness to accept.

To alleviate the deteriorating environment and protect biodiversity, China has implemented a natural forest protection system, demonstrating the importance of sustainable forest management for ecological conservation and socio-economic development, including the complete cessation of commercial logging of natural forests. Financial compensation is adopted to increase farmers' enthusiasm within the commercial Logging Ban of Natural Forests framework. This study used the contingent valuation method and the Heckman two-stage model to explore farmers' willingness to participate in the Logging Ban of Natural Forests and the willingness to accept by survey data on 486 farming households. 72% of farmers are willing to join the Logging Ban of Natural Forests. Their willingness to accept is 517.95 yuan/ha per year, higher than the current state subsidy standard (225 yuan/ha per year). The key factors influencing willingness to accept include the education and degree of fragmentation of woodland and village collective willingness to accept. The age of the rural household head, the fragmentation of the forest, and the evaluation of the Logging Ban of Natural Forests policies have inhibited the increase of farmers' compensation. Farmers' assessment of the Logging Ban of Natural Forests policy only impacts the medium level of compensation. The age and the degree of forest fragmentation would affect the higher compensation amount. The results from this study suggest more financial sources and increased compensation standards are needed. The government should also strengthen ecological awareness and adopt different compensation standards for other groups to achieve sustainable forestry.

Consumer-Related Antecedents of Waste Behavior in Online Food Ordering: A Study among Young Adults in China.

Food waste in the catering industry currently accounts for almost half of the total food waste in China and entails a large amount of land, water, and labor costs, in addition to the carbon footprint's impacts on climate change. Under the background of increasing food consumption and waste from online catering, this study investigates the factors influencing the food waste behaviors (FW) of online food ordering in China and provides policy recommendations for food waste reduction. Using survey data from 482 consumers, we constructed a theoretical framework and examined the influence path of each factor using structural equation modeling (SEM) and a bootstrap test. The results showed that young consumers without farming experience and females wasted more on ordering food online. The more frequently the consumer ordered, the more they wasted. The level of consumers' perceived behavioral control (PBC) was found to be lower than other factors, indicating that it was difficult for consumers to reduce food waste. Attitudes toward behavior (ATT), subjective norm (SN), PBC, and price consciousness (PC) were all positively related to behavioral intention to reduce food waste (BI). PBC and BI were negatively related to FW, and over-consumption behavior (OC) was positively related to FW. BI had a mediating effect on the paths of ATT, PBC, and PC to FW, but the pathway through which PC influenced FW was primarily through BI or PBC, not OC. In our research, BI had no mediating effect between SN and FW. Ultimately, our findings inform some policy recommendations to help nations, restaurants, food-ordering platforms, and consumers reduce waste.

Economic development, rural livelihoods, and ecological restoration: evidence from China.

This article uses a case study in Southeast China to demonstrate how the substantial changes in rural livelihoods have been driven by a combination of "pull" forces from external economic development, and "push" forces from local areas, leading to a shift in rural household economic activities: household outmigration and de-population of the countryside, changes in energy consumption, and most importantly, changes in land uses and eventually, ecological restoration. Such dramatic changes are becoming common across the Chinese countryside. It is pointed out that economic development has generally caused a deterioration of the environment at least at the early period of economic growth, but the positive impacts, especially in some ecosystem in rural areas, have become more apparent.

Rehabilitating China's largest inland river.

Wetlands are particularly important for conserving China's biodiversity but riparian wetlands in the Tarim River basin in western China have been reduced by 46% during the last 3 decades. The world's largest habitat for Populus euphratica, which is in the Tarim River basin, significantly shrank. To protect and restore the deteriorated ecosystems along the Tarim River and its associated wetlands, China's government initiated a multimillion dollar river restoration project to release water from upper dams to the dried-up lower reaches of the Tarim River starting in 2000. We monitored the responses of groundwater and vegetation to water recharge in the lower reaches of the river from 2000 to 2006 by establishing nine 1000-m-long transects perpendicular to the river at intervals of 20-45 km along the 320-km river course below the Daxihaizi Reservoir, the source of water conveyance, to Lake Taitema, the terminus of the Tarim River. Water recharges from the Daxihaizi Reservoir to the lower reaches of the Tarim River significantly increased groundwater levels and vegetation coverage at all monitoring sites along the river. The mean canopy size of the endangered plant species P. euphratica doubled after 6 years of water recharge. Some rare migrating birds returned to rest on the restored wetlands in summer along the lower reaches of the Tarim River. The biggest challenge facing decision makers, however, is to balance water allocation and water rights between agricultural and natural ecosystems in a sustainable way. A large number of inhabitants in the Tarim Basin depend on these limited water resources for a living. At the same time, the endangered ecosystems need to be protected. Given the ecological, socioeconomic, and sociopolitical realities in the Tarim Basin, adaptive water policies and strategies are needed for water allocation in these areas of limited water resources.

Effects of 8-Year Nitrogen and Phosphorus Treatments on the Ecophysiological Traits of Two Key Species on Tibetan Plateau.

Understanding how nitrogen (N) and/or phosphorus (P) addition affects plants carbon- and water- related ecophysiological characteristics is essential for predicting the global change impact on the alpine meadow ecosystem structure and function in carbon and water cycling. The Qinghai-Tibetan Plateau (QTP) with the largest alpine meadow in the world is regarded as the third pole in the earth and has been experiencing increased atmospheric N deposition. In this project, we focused on two key species (Elymus dahuricus and Gentiana straminea) of the alpine meadow on the Tibetan Plateau and investigated the variability of photosynthetic and stomatal responses to 8-year N and/or P treatments through field measurements and modeling. We measured photosynthesis- and gs-response curves to generate parameter estimates from individual leaves with two widely used stomatal models (the BWB model and MED model) for validation of growth and ecosystem models and to elucidate the physiological basis for observed differences in productivity and WUE. We assessed WUE by means of gas exchange measurements (WUEi) and stable carbon isotope composition (Δ13C) to get the intrinsic and integrated estimates of WUE of the two species. P and N+P treatments, but not N, improved the photosynthetic capacity (Anet and Vcmax) for both species. Stomatal functions including instaneous measurements of stomatal conductance, intrinsic water-use efficiency and stomatal slope parameters of the two widely used stomatal models were altered by the addition of P or N+P treatment, but the impact varied across years and species. The inconsistent responses across species suggest that an understanding of photosynthetic, stomatal functions and water-use should be evaluated on species separately. WUE estimated by Δ13C values had a positive relationship with Anet and gs and a negative relationship with WUEi. Our findings should be useful for understanding the underlying mechanisms of the response of alpine plants growth and alpine meadow ecosystem to global change.

The spatio-temporal dynamic pattern of rural residential land in China in the 1990s using Landsat TM images and GIS.

Through interpreting Landsat TM images, this study analyzes the spatial distribution of rural settlements in China in 2000. It calculates rural residential land percentage for every 1-km(2) cell. The entire country is divided into 33 regions to investigate the spatio-temporal dynamic patterns of rural residential land during the 1990s. According to the remote sensing survey, the rural residential land increased by 7.88 x 10(5) ha in the 1990s. The increment of rural residential land was 0.55 million ha in 1990-1995 and 0.23 million ha in 1995-2000. In 1990-1995, rural residential land increased dramatically in the eastern regions such as the Yangtze River Delta, Pearl River Delta, and North China Plain, accounting for 80.80% of the national growth; the expansion in the western regions was much more moderate. In 1995-2000, the expansion of rural residential land in eastern regions slowed, accounting for only 58.54% of the increase at the national level, whereas the expansion in the western regions accelerated. Rapid rural residential development resulted from increasing home construction and the limited control on rural land. The great regional disparity reflected the regional economic development and land-use policy change. Our finding shows that nearly 60% of the rural residential area came from cropland.