Spontaneous Gene Flow between Cultivated and Naturalized Vicia villosa Roth Populations Increases the Physical Dormancy Seed in a Semiarid Agroecosystem

Hairy vetch (Vicia villosa Roth) is the second most cultivated vetch worldwide being used as a forage and cover crop. As it is not domesticated, it displays several wild traits including seed dormancy. The physical seed dormancy (PY) variation could be useful depending on the specific context. High PY is desirable for ley farming systems, while low PY is needed to prevent weediness in subsequent crop rotations. Gene flow between cultivated and naturalized populations has important ecological and agronomic consequences. Experiments were conducted to determine the change in the level of PY in spontaneous crosses between European cultivated accessions (EU) characterized by low PY and naturalized Argentinian population (AR) with high PY. Generations G0 (initial generation) to G3 were assessed for their PY in seeds and total dry matter (DM) per plot, at plant maturity. As the result of spontaneous crosses with the AR population, an increase from G0 to G3 in PY and DM in EU accessions was observed, while AR maintained its high PY and DM values. In one mating cycle, selecting for PY lower than 14% and high DM can satisfy breeding objectives for cover crops. Isolation during breeding and seed production is necessary to avoid gene flow. This knowledge extends to other legume species with gene flow between wild and cultivated populations.

GENERATION OF TRAINING INITIAL GENERATION CONTENT

The influence of the automation of content creation on the development trends of e-education based on artificial intelligence is considered. Widely used content generators do not actually create new content but modify the finished content accumulated in the databases. The concept of generating primary content is based on the use of simulation models of the studied objects. The methodology for generating the content initial-generation demonstrates the possibility of incorporating AI-based content management sys- tems into e-education.

First proofs of preservation of a Mesozoic paleorelief in Southeast Africa: Insights from the (U-Th)/He dating of iron oxides from Malawian duricrusts

<p>Approximately 70% of the emerged relief on the Earth is characterized by erosional low-gradient topography also known as planation surfaces (PS). Many geomorphologists defend the idea that some of these surfaces could be relics of old reliefs uplifted and preserved from erosion for tens of millions years. Some of the highest PS of Southeast Africa (> 2000 m) were considered by King (1962) as remnants of an ante-Cretaceous paleorelief called “Gondwana Surface”. Specifically, the Nyika Plateau (Northern Malawi, 2200 m) is one of the largest potential relics of the “Gondwana Surface” in Southeastern Africa. This PS overlooks the stripped etchplain of the Malawian Plateau, a potential Late Cretaceous PS about 1200 m of elevation.</p><p>However, the preservation of such ancient reliefs is controversial, particularly under a tropical wet-dry climate. Doubts about the ages of these PS exist mainly due to the lack of a precise chronology of these objects on a continental scale. In detail, African PS are often covered by preserved or partly eroded tropical weathering covers such as unconsolidated laterites and/or duricrusts. Under these climatic conditions, lateritic duricrusts can be preserved for millions of years and thus contain several generations of iron oxides witnesses of past local paleoenvironment and geodynamic evolution. In order to understand the formation and preservation of the Southeast African highest PS and date them, we decided to apply (U-Th)/He dating of iron oxides on selected duricrust samples. The exploration of the Nyika Plateau allowed the discovery of an outcropping duricrust and a depositional area of eroded duricrust blocks from different origins. We study duricrust samples from these two areas in order to find some clues about the plateau antiquity and to improve our knowledge about the local paleoclimatic and geodynamic history.</p><p>Samples from the in situ duricrust levels, outcropping on the plateau, are polygenic and are formed by three main types of zones: preserved and degraded hematite-rich zones, that are considered to correspond to the initial generation of iron oxides, and a goethitic matrix. The preserved hematites have a Mesozoic (U-Th)/He ages, whereas the goethite-rich matrix of this duricrust formed during the Quaternary. The degraded hematite-rich parts, also rich in quartz, have more dispersed ages ranging from the Mesozoic to the Tertiary. In the detrital accumulation zone, blocks from a similar duricrust were found as well as blocks of another type of duricrusts: a pisolithic one rich in goethite. This last type of duricrust was eroded from a more recent duricrust level, as their iron oxides have Late Tertiary/Quaternary ages. These dating proved the Nyika Plateau relative stability since the Mesozoic period, confirming that duricrusting of reliefs in tropical area can also protect old emerged landscapes from total erosion.</p><p>King L.C. (1962) Morphology of Earth, Oliver and Boyld, Edinburg.</p><p> </p>

β-Blockers in Metabolic and Endocrine Perspectives

Catecholamine, through α-adrenergic receptor and β-adrenergic receptor activation, plays many roles in body’s physiological and pathophysiologicalprocesses. β-adrenergic receptor has different effect pursuant to receptor type, receptor location and G protein activation in the receptor. Beta receptor blockers (β-blockers) are a drug commonly used for cardiovascular disease. There are 3 different generations of β-blockers. In addition to their great advantages in cardiovascular, β-blockers also have metabolic and endocrine effects. β-blocker may influence sugar and insulin, fat, melatonin, cancer, blood uric acid and thyroid hormone metabolism. These metabolic effects may be disadvantageous, which mostly takes place with initial generation β-blockers. Third generation β-blockers do not show disadvantageous metabolic effect. However, early generation β-blockers may be advantageous in certain condition.

Retirement Financing: An Optimal Reform Approach

We study Pareto optimal policy reforms aimed at overhauling retirement financing as an integral part of the tax and transfer system. Our framework for policy analysis is a heterogeneous‐agent overlapping‐generations model that performs well in matching the aggregate and distributional features of the U.S. economy. We present a test of Pareto optimality that identifies the main source of inefficiency in the status quo policies. Our test suggests that lack of asset subsidies late in life is the main source of inefficiency when annuity markets are incomplete. We solve for Pareto optimal policy reforms and show that progressive asset subsidies provide a powerful tool for Pareto optimal reforms. On the other hand, earnings tax reforms do not always yield efficiency gains. We implement our Pareto optimal policy reform in an economy that features demographic change. The reform reduces the present discounted value of net resources consumed by each generation by about 7 to 11 percent in the steady state. These gains amount to a one‐time lump‐sum transfer to the initial generation equal to 10.5 percent of GDP.

Learning from Others' Outcomes

I develop a simple model of social learning in which players observe others’ outcomes but not their actions. A continuum of players arrives continuously over time, and each player chooses once-and-for-all between a safe action (which succeeds with known probability) and a risky action (which succeeds with fixed but unknown probability, depending on the state of the world). The actions also differ in their costs. Before choosing, a player observes the outcomes of K earlier players. There is always an equilibrium in which success is more likely in the good state, and this alignment property holds whenever the initial generation of players is not well informed about the state. In the case of an outcome-improving innovation (where the risky action may yield a higher probability of success), players take the correct action as K → ∞. In the case of a cost-saving innovation (where the risky action involves saving a cost but accepting a lower probability of success), inefficiency persists as K → ∞ in any aligned equilibrium. Whether inefficiency takes the form of under-adoption or over-adoption also depends on the nature of the innovation. Convergence of the population to equilibrium may be nonmonotone. (JEL D81, D83, O32, Q12, Q16)

Synthesis of Functionalized Cyclopentene Derivatives through Gold-Catalyzed Reaction of Stabilized Vinyldiazo Compounds and Styrenes

The reaction of alkenyldiazo compounds with styrene derivatives in the presence of [Au(IPr)(MeCN)][SbF6] provided cyclopentene derivatives resulting from a formal [3+2] cycloaddition reaction as major products. This reaction outcome stands in marked contrast to that previously observed for other olefinic derivatives. From a mechanistic point of view, this process would involve the initial generation of a highly electrophilic alkenylgold carbene intermediate, which would be subsequently involved in a stepwise carbocationic process.

Multiple Fungicide Resistance in Botrytis cinerea from Greenhouse Strawberries in Hubei Province, China

Two hundred and forty isolates of Botrytis cinerea were collected during the early summer of 2012 and 2013 from strawberry greenhouses in 10 locations in Hubei Province and examined for sensitivity to five fungicides, most of which were commonly used to control this fungus. High frequency of resistance to carbendazim (Car, 63.63%) and cyprodinil (Cyp, 42.42%) was detected. Boscalid-resistant (BosR) isolates were detected for the first time in China, whereas no fludioxonil-resistant isolates were identified. Dual resistance to carbendazim and diethofencarb (Die) was also detected. There were six phenotypes of resistance profile (i.e., CarRDieSBosSCypS, CarRDieRBosSCypS, CarRDieSBosSCypR, CarRDieSBosRCypS, CarRDieRBosSCypR, and CarRDieSBosRCypR). CarRDieSBosSCypS and CarRDieSBosSCypR were the most common phenotypes, occurring at eight and seven locations, respectively. After 10 successive transfers on fungicide-free potato dextrose agar, tested resistant isolates retained levels of resistance similar to or comparative with the initial generation, indicating the stability of these resistances. Fitness evaluations based on investigation of mycelial growth, osmotic sensitivity, sporulation in vitro and in vivo, and virulence revealed the uncompromising fitness in resistant isolates, except that decreased virulence was observed in BosR isolates. The molecular basis of carbendazim, diethofencarb, and boscalid resistance was investigated. Results showed that all 13 sequenced carbendazim-resistant isolates harbored the mutation E198V or E198A in the β-tubulin gene and the five isolates with dual resistance to carbendazim and diethofencarb showed the mutation E198K in the same gene. BosR isolates possessed the H272R mutation in succinate dehydrogenase subunit B gene. The results achieved in this study challenge the current management strategies for B. cinerea, which largely depend on applications of these fungicides.