A tragedy of the commons (TOC) occurs when individuals acting in their own self-interest deplete commonly held resources, leading to a worse outcome than had they cooperated. Over time, the depletion ...of resources can change incentives for subsequent actions. Here, we investigate long-term feedback between game and environment across a continuum of incentives in an individual-based framework. We identify payoff-dependent transition rules that lead to oscillatory TOCs in stochastic simulations and the mean field limit. Further extending the stochastic model, we find that spatially explicit interactions can lead to emergent, localized dynamics, including the propagation of cooperative wave fronts and cluster formation of both social context and resources. These dynamics suggest new mechanisms underlying how TOCs arise and how they might be averted.
A 27-42-GHz 5-bit passive switching phase shifter is presented using 65-nm CMOS technology for the fifth generation (5G) applications. In the 180° phase shift bit, a reflection-type-based biphase ...modulator topology is developed to achieve good phase shifting performance over a wide bandwidth. The measured insertion loss (IL) of all 32 states is 12.4 ± 1.2 dB at 39 GHz and 11.4 ± 2.3 dB at 28 GHz with zero dc power. The phase shifter demonstrates an ultralow root mean square (rms) phase error of 0.7° and a low rms amplitude error of 0.8 dB at 37 GHz with an inherent digital phase-control mechanism. The rms phase error is less than 3.8° and the rms amplitude error is less than 2.1 dB from 27 to 42 GHz.
Drought and salinity are two major environmental factors limiting crop production worldwide. Improvement of drought and salt tolerance of crops with transgenic approach is an effective strategy to ...meet the demand of the ever‐growing world population. Arabidopsis ENHANCED DROUGHT TOLERANCE1/HOMEODOMAIN GLABROUS11 (AtEDT1/HDG11), a homeodomain‐START transcription factor, has been demonstrated to significantly improve drought tolerance in Arabidopsis, tobacco, tall fescue and rice. Here we report that AtHDG11 also confers drought and salt tolerance in upland cotton (Gossypium hirsutum) and woody plant poplar (Populus tomentosa Carr.). Our results showed that both the transgenic cotton and poplar exhibited significantly enhanced tolerance to drought and salt stress with well‐developed root system. In the leaves of the transgenic cotton plants, proline content, soluble sugar content and activities of reactive oxygen species‐scavenging enzymes were significantly increased after drought and salt stress compared with wild type. Leaf stomatal density was significantly reduced, whereas stomatal and leaf epidermal cell size were significantly increased in both the transgenic cotton and poplar plants. More importantly, the transgenic cotton showed significantly improved drought tolerance and better agronomic performance with higher cotton yield in the field both under normal and drought conditions. These results demonstrate that AtHDG11 is not only a promising candidate for crops improvement but also for woody plants.
Summary
Nitrogen (N) is one of the key essential macronutrients that affects rice growth and yield. Inorganic N fertilizers are excessively used to boost yield and generate serious collateral ...environmental pollution. Therefore, improving crop N use efficiency (NUE) is highly desirable and has been a major endeavour in crop improvement. However, only a few regulators have been identified that can be used to improve NUE in rice to date. Here we show that the rice NIN‐like protein 4 (OsNLP4) significantly improves the rice NUE and yield. Field trials consistently showed that loss‐of‐OsNLP4 dramatically reduced yield and NUE compared with wild type under different N regimes. In contrast, the OsNLP4 overexpression lines remarkably increased yield by 30% and NUE by 47% under moderate N level compared with wild type. Transcriptomic analyses revealed that OsNLP4 orchestrates the expression of a majority of known N uptake, assimilation and signalling genes by directly binding to the nitrate‐responsive cis‐element in their promoters to regulate their expression. Moreover, overexpression of OsNLP4 can recover the phenotype of Arabidopsis nlp7 mutant and enhance its biomass. Our results demonstrate that OsNLP4 plays a pivotal role in rice NUE and sheds light on crop NUE improvement.
ABSTRACT
Research Question/Issue
Are companies monitored by common owners (i.e., institutional investors that block‐own owning 5% or more several companies in a single industry) more likely than ...other companies to record goodwill impairments when their assets are overstated?
Research Findings/Insights
We find that companies monitored by common owners are more likely than other companies to record goodwill impairments when their assets are overstated. The monitoring effect is stronger for common owners with a stronger incentive to monitor and with more industry knowledge and stronger for the co‐presence of multiple common owners. Our findings are in line with the notion that common owners have an economy of scale in monitoring and internalize the negative externality of delayed recording of goodwill impairment. We also find that common ownership is associated with lower information asymmetry, which in turn increases the timeliness of goodwill impairment.
Theoretical/Academic Implications
Our research emphasizes the monitoring role of common ownership in recording goodwill impairments. We find support for the mechanisms enabling common owners to be better monitors.
Practitioner/Policy Implications
The prevalence of common ownership has prompted regulatory and societal concerns regarding under‐investment in the oversight of the companies. Our findings documenting the association between common ownership and the timely recording of goodwill impairments are relevant to the ongoing debate regarding the potential costs and benefits of common ownership.
• Seed germination is a crucial transition point in plant life and is tightly regulated by environmental conditions through the coordination of two phytohormones, gibberellin and abscisic acid (ABA). ...To avoid unfavorable conditions, plants have evolved safeguard mechanisms for seed germination.
• The present contribution reports a novel function of the Arabidopsis MCM1/AGAMOUS/DEFICIENS/SRF(MADS)-box transcription factor ARABIDOPSIS NITRATE REGULATED 1 (ANR1) in seed germination.
• ANR1 knockout mutant is insensitive to ABA, salt and osmotic stress during the seed germination and early seedling development stages, whereas ANR1-overexpressing lines are hypersensitive. ANR1 is responsive to ABA and abiotic stresses and upregulates the expression of ABA Intolerant (ABI)3 to suppress seed germination. ANR1 and ABI3 have similar expression pattern during seed germination. Genetically, ABI3 acts downstream of ANR1. Chromatin immunoprecipitation and yeast-one-hybrid assays showed that ANR1 could bind to the ABI3 promoter to regulate its expression. In addition, ANR1 acts synergistically with AGL21 to suppress seed germination in response to ABA as evidenced by anr1 agl21 double mutant.
• Taken together, the results herein demonstrate that the ANR1 plays an important role in regulating seed germination and early postgermination growth. ANR1 and AGL21 together constitutes a safeguard mechanism for seed germination to avoid unfavorable conditions.
Jasmonic acid (JA) is well known to promote lateral root formation but the mechanisms by which JA signalling is integrated into the pathways responsible for lateral root formation, and how it ...interacts with auxin in this process remains poorly understood. Here, we report that the highly JA-responsive ethylene response factor 109 (ERF109) mediates cross-talk between JA signalling and auxin biosynthesis to regulate lateral root formation in Arabidopsis. erf109 mutants have fewer lateral roots under MeJA treatments compared with wild type whereas ERF109 overexpression causes a root phenotype that resembles those of auxin overproduction mutants. ERF109 binds directly to GCC-boxes in the promoters of ASA1 and YUC2, which encode two key enzymes in auxin biosynthesis. Thus, our study reveals a molecular mechanism for JA and auxin cross-talk during JA-induced lateral root formation.
Abstract
Nitrogen (N) is indispensable for crop growth and yield, but excessive agricultural application of nitrogenous fertilizers has generated severe environmental problems. A desirable and ...economical solution to cope with these issues is to improve crop nitrogen use efficiency (NUE). Plant NUE has been a focal point of intensive research worldwide, yet much still has to be learned about its genetic determinants and regulation. Here, we show that rice (Oryza sativa L.) NIN-LIKE PROTEIN 1 (OsNLP1) plays a fundamental role in N utilization. OsNLP1 protein localizes in the nucleus and its transcript level is rapidly induced by N starvation. Overexpression of OsNLP1 improves plant growth, grain yield, and NUE under different N conditions, while knockout of OsNLP1 impairs grain yield and NUE under N-limiting conditions. OsNLP1 regulates nitrate and ammonium utilization by cooperatively orchestrating multiple N uptake and assimilation genes. Chromatin immunoprecipitation and yeast one-hybrid assays showed that OsNLP1 can directly bind to the promoter of these genes to activate their expression. Therefore, our results demonstrate that OsNLP1 is a key regulator of N utilization and represents a potential target for improving NUE and yield in rice.
OsNLP1 rapidly responds to N availability, enhances N uptake and assimilation, providing great potential for breeding rice cultivars with high yield and NUE under N-limiting conditions
Nitrogen (N) is an essential macronutrient for crop growth and yield. Improving the N use efficiency (NUE) of crops is important to agriculture. However, the molecular mechanisms underlying NUE ...regulation remain largely elusive. Here we report that the OsNLP3 (NIN‐like protein 3) regulates NUE and grain yield in rice under N sufficient conditions. OsNLP3 transcript level is significantly induced by N starvation and its protein nucleocytosolic shuttling is specifically regulated by nitrate. Loss‐of‐function of OsNLP3 reduces plant growth, grain yield, and NUE under sufficient nitrate conditions, whereas under low nitrate or different ammonium conditions, osnlp3 mutants show no clear difference from the wild type. Importantly, under sufficient N conditions in the field, OsNLP3 overexpression lines display improved grain yield and NUE compared with the wild type. OsNLP3 orchestrates the expression of multiple N uptake and assimilation genes by directly binding to the nitrate‐responsive cis‐elements in their promoters. Overall, our study demonstrates that OsNLP3, together with OsNLP1 and OsNLP4, plays overlapping and differential roles in N acquisition and NUE, and modulates NUE and the grain yield increase promoted by N fertilizer. Therefore, OsNLP3 is a promising candidate gene for the genetic improvement of grain yield and NUE in rice.
Summary Statement
Crop nitrogen use efficiency (NUE) is an important agronomic trait. But the molecular mechanisms underlying NUE regulation are not well understood. This study reveals that rice NIN‐like protein 3 (OsNLP3) regulates NUE and grain yield especially under N sufficient conditions and is a promising candidate gene for improving grain yield and NUE in rice.
Nitrogen is essential for plant survival and growth. Excessive application of nitrogenous fertilizer has generated serious environment pollution and increased production cost in agriculture. To deal ...with this problem, tremendous efforts have been invested worldwide to increase the nitrogen use ability of crops. However, only limited success has been achieved to date. Here we report that NLP7 (NIN-LIKE PROTEIN 7) is a potential candidate to improve plant nitrogen use ability. When overexpressed in Arabidopsis, NLP7 increases plant biomass under both nitrogen-poor and -rich conditions with better-developed root system and reduced shoot/root ratio. NLP7-overexpressing plants show a significant increase in key nitrogen metabolites, nitrogen uptake, total nitrogen content, and expression levels of genes involved in nitrogen assimilation and signalling. More importantly, overexpression of NLP7 also enhances photosynthesis rate and carbon assimilation, whereas knockout of NLP7 impaired both nitrogen and carbon assimilation. In addition, NLP7 improves plant growth and nitrogen use in transgenic tobacco (Nicotiana tabacum). Our results demonstrate that NLP7 significantly improves plant growth under both nitrogen-poor and -rich conditions by coordinately enhancing nitrogen and carbon assimilation and sheds light on crop improvement.
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