Extreme Mei-yu in 2020:Characteristics, causes, predictability and perspectives

The 2020 extreme rainfall was highly unusual with episodes of intensive rains and winds from the middle and lower reaches of the Yangtze River Valley to southern Japan. Given the severe implications and huge forecast spread among different models, the extreme Mei-yu has aroused widespread concern. This study is aimed at synthesizing the latest research on the characteristics and potential climate forcing factors of such extreme Mei-yu and discusses the challenges and outlooks for prediction and numerical modeling. The distinct characteristics of the Yangtze River Valley summer rainfalls in 2020 included record-breaking accumulated precipitation, longest duration, earliest onset, and highest intensity. We summarize the majority of the studies investigating the diverse coupled ocean-atmospheric processes at different timescales. The research consensus is that the anomalous anticyclone spanning the western North Pacific and the mid-high latitude trough-ridge patterns are the two critical circulation features carrying tropical and mid-high latitude signals, jointly affecting the extreme Mei-yu. Potential mechanisms based on the two essential atmospheric circulations during the Mei-yu period are then highlighted. In addition, different climate model simulations are also introduced to reach an inter-model agreement despite certain model biases on the response of atmospheric circulations to these potential forcings among the state-of-the-art atmospheric and coupled general circulation models. This study provides a synthesis to promote the understanding, prediction, and disaster prevention of extreme Mei-yu.</p

Gold and diamond artisanal mining in Liberia:Under the umbrella of (in)formality?

Liberia intends to harness the development potential of artisanal mining through formalization. However, there are several obstacles that the country needs to overcome for it to succeed. The existing literature provides evidence on the challenges faced by miners and local authorities, but fails to make a distinction between different types of activities. This study sets out to identify differences in formalization patterns across the two largest artisanal sectors, namely gold and diamond mining. Drawing on an extensive survey of 231 communities and 174 mines in Gbarpolu County, we spatially match mining sites to their nearest license recorded in the country's cadastre. To do so, we consider both distance to licenses and concentration of mines around titles before loosening the definition of formality by exploring town chiefs’ perceptions. We complement our spatial analysis with qualitative insights into miners’ views on the challenges and opportunities of artisanal gold versus diamond mining. Our findings show that artisanal diamond mines are more likely to fall under what we define as an “umbrella of formality” compared to gold mines. We explain this difference through geology, but also the history and perceptions of the respective minerals. Against this backdrop, we question the effectiveness of formalization as it is currently conceived in Liberia. We argue that distinguishing between artisanal mining sectors is important to understand the different sets of incentives and constraints that miners face. This, in turn, is key to the design of tailored and effective formalization policies.</p

The representation of occluded image regions in area V1 of monkeys and humans

Neuronal activity in the primary visual cortex (V1) is driven by feedforward input from within the neurons’ receptive fields (RFs) and modulated by contextual information in regions surrounding the RF. The effect of contextual information on spiking activity occurs rapidly and is therefore challenging to dissociate from feedforward input. To address this challenge, we recorded the spiking activity of V1 neurons in monkeys viewing either natural scenes or scenes where the information in the RF was occluded, effectively removing the feedforward input. We found that V1 neurons responded rapidly and selectively to occluded scenes. V1 responses elicited by occluded stimuli could be used to decode individual scenes and could be predicted from those elicited by non-occluded images, indicating that there is an overlap between visually driven and contextual responses. We used representational similarity analysis to show that the structure of V1 representations of occluded scenes measured with electrophysiology in monkeys correlates strongly with the representations of the same scenes in humans measured with functional magnetic resonance imaging (fMRI). Our results reveal that contextual influences rapidly alter V1 spiking activity in monkeys over distances of several degrees in the visual field, carry information about individual scenes, and resemble those in human V1.</p

The displacement effect of compulsory pension savings on private savings. Evidence from the Netherlands, using pension funds supervisory data

We show heterogenous displacement effects of mandatory occupational pension savings on private household wealth for different groups. Richer households in particular show larger displacements. This contributes to explaining why empirical studies often come with different estimates of this effect. We study the case of the Netherlands, where wage employed and self-employed workers are differently exposed to compulsory pension savings, and the institutional setting provides exogenous variation in pension wealth that can be used as instrument in the analysis. We use rich administrative data on (pension) wealth and income combined for the first time to supervisory data of pension funds. Our results show a displacement effect of −37% for wage employed and of −61% to −77% for self-employed people. The higher displacement effect we find for the self-employed might be explained by the fact that self-employed workers are arguably more aware of their pension accrual, or lack thereof, because there is no employer who organizes and (partly) pays this for them.</p

A novel and facile synthesis of calcium silicate nanoparticles as a base for root canal cement/sealer under constant potential:Compared to chemical synthesis

Among inorganic biomaterials, which recently have received great attention in regenerative medicine, calcium silicate-based cements are bioactive materials that are prepared based on a composition of calcium and silicate. This manuscript explores the synthesis of pure calcium silicate (CaSiO3) nanoparticles using two different methods: sol-gel synthesis and electrochemical synthesis. The goal is to compare the structural characteristics of the synthesized products. In the sol-gel method, CaSiO3 is prepared using tetraethyl orthosilicate (TEOS) and calcium nitrate tetrahydrate, while in the electrochemical method; CaSiO3 is synthesized under constant potential using the same materials. The resulting nanoparticles were characterized using various analytical techniques such as scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction analysis (XRD). Additionally, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were performed. The XRD analysis revealed crystal sizes of 21 nm and 39.94 nm for electrochemical and chemical synthesis, respectively, indicating the formation of wollastonite-type CaSiO3 in the electrochemical method. SEM analysis showed average particle sizes of 62.44 nm and 119 nm for electrochemical and chemical synthesis, respectively. The results demonstrate that the proposed electrochemical method offers a simple, rapid, inexpensive, and high-purity approach for the synthesis of CaSiO3, which can serve as an alternative to chemical methods. The findings of this study contribute to the development of biomaterials for dental and medical applications.</p

Impact of try-in paste removal on the fatigue behavior of bonded lithium disilicate ceramics

This in vitro study assessed the effectiveness of three cleaning protocols (air-water spray, 37% phosphoric acid, or Ivoclean) on lithium disilicate restorations' fatigue behavior after try-in paste application, compared to a clean condition. Lithium disilicate discs (IPS e.max CAD, Ivoclar) with Ø-= 12 mm and 1 mm thickness were prepared from prefabricated CAD-CAM blocks, polished, subjected to CAD-CAM milling topography simulation and crystallization. After, etching with 5% hydrofluoric acid and the application of try-in paste (Variolink try-in paste shade white; load of 2.5 N for 5 min) was performed. Discs that received try-in paste were divided into three groups according to the removal protocol: SPRAY – air-water spray for 30 s; HPO – active application of 37% phosphoric acid for 60 s; IVOC – application of Ivoclean for 20 s. Control group (CTRL group) did not receive the try-in paste application. Half of the specimens (n= 15) were tested in the baseline condition (24 h up to 7 days), and the others underwent 25,000 thermal cycles (5 – 55 °C) + 210 days of distilled water storage (37 °C). Additional specimens (n= 3) underwent monotonic testing (1 mm/min). Fatigue testing involved a cyclic fatigue approach (20 Hz, initial load = 100 N – 5000 cycles, step size = 50 N – 10,000 cycles) until a visible crack appeared. Fractographic and topographic analyses were performed. Fatigue data were statistically analyzed with two-way ANOVA, Kaplan-Meier log-rank (Mantel-Cox), and independent t-test (α= 0.05). In the baseline condition, the IVOC group resulted in a superior fatigue behavior compared to the CTRL and SPRAY groups, but similar to the HPO group. The HPO and SPRAY presented a similar fatigue behavior to the CTRL group. It was noticed a decrease in fatigue behavior after aging, which resulted in all the cleaning protocols leading to similar fatigue behavior compared to the CTRL group. On the SPRAY group surface, try-in pastes remnants were noticed. In summary, despite a detrimental impact at baseline conditions, all tested cleaning protocols seem proper to remove the try-in paste from the ceramic's surface in the long-term evaluation.</p

The coincidence of climate extremes with sensitive crop growth phases:Projected impact on sustainable crop water use and crop yield in the IGB river basins

Increased climate variability and extremes are unequivocal with unprecedented impacts on water resources and agriculture production systems. However, little is known about the impacts of climate extremes at the intra-seasonal level which remained largely unexplored. We investigated the coincidence of climate extremes with sensitive crop growth phases of wheat and rice in the Indus, Ganges and Brahmaputra (IGB) river basins of South Asia. We also quantified the related impacts on irrigation water demand (IWD), gross primary production (GPP) and crop yields (CY) simulated by a hydrological-vegetation model (LPJmL) during 1981–2100 using RCP4.5-SSP1 and RCP8.5-SSP3 framework. The climate extremes revealed a higher frequency and intensity during crop growth phases with significant increasing trends in future. Diverse changes in IWD, GPP and CY are projected in future under the influence of crop phase-specific extremes. The crop phase-specific changes in the IWD of wheat and rice will intensify in the future. More than 50 % of the change in future wheat irrigation is caused by warm and dry extremes during the ripening phase. Whereas, increase in IWD for rice is mainly associated with warm extremes only. The crop phase-specific GPP shows a decreasing trend in future for both wheat and rice in the Western part of IGB with the largest decrease during the reproductive phase of wheat (up to 36 %) and vegetative phase of rice (&gt;20 %). This decrease is clearly reflected in seasonal yields i.e., both wheat (20 %) and rice (12 %) showed a decrease in future linked with warm and dry extremes. However, in the Eastern part of IGB, the GPP will mostly increase in future during the three crop phases of wheat and rice. These results can be used to help develop efficient adaptation strategies considering seasonal changes and sensitive crop phases for sustained food and water security in South Asia.</p

Procedural Strategies

In this chapter, we first discuss analysis methods for understanding processes of relative importance and compositionality in the model using attribution signals. In the second part, we introduce methods to link these interpretability metrics to phenomena that we observe in cognitive signals. We then discuss how we can adjust the target objective and the inductive bias of the model towards cognitively more plausible procedural patterns.</p

Procedural Strategies

In this chapter, we first discuss analysis methods for understanding processes of relative importance and compositionality in the model using attribution signals. In the second part, we introduce methods to link these interpretability metrics to phenomena that we observe in cognitive signals. We then discuss how we can adjust the target objective and the inductive bias of the model towards cognitively more plausible procedural patterns.</p