The Liuqu Formation in southern Tibet, China, archives the late Palaeocene Liuqu flora (ca. 56 Ma) and represents ancient vegetation on the northern margin of the Indian Plate near the India–Asia collision zone. It therefore provides critical evidence for evaluating early biotic interactions between India and Eurasia. Here, we report on Syzygium (Myrtaceae) fossil leaves from the Liuqu flora. Detailed morphological comparisons suggest that these specimens represent a new fossil species, namely Syzygium ovatum Y. Gao et T. Su sp. nov. By integrating fossil records with deep-time ecological niche modelling, we infer that Syzygium originated on the Indian Plate before or during the Palaeocene. By the middle Eocene, Syzygium had migrated to the northeast along the Asian Pacific coastline to East Asia, consistent with an “Out-of-India” dispersal scenario. Fossil evidence demonstrates that the genus reached New Zealand and Australia by the Early Miocene, likely through a Southeast Asian dispersal corridor. During the Pliocene, the distribution of Syzygium resembled that of its modern range. Although the African fossil record of Syzygium only dates to the early Pliocene, climatic suitability and favourable paleogeographic conditions suggest an earlier arrival: 1) during the Palaeocene via the Kohistan–Ladakh Island Arc and associated island systems or 2) during the Oligocene, when more suitable areas for Syzygium linked Africa and India. Generally, our results suggest a Palaeocene origin of Syzygium on the Indian Plate instead of an early Eocene Australian origin as previously proposed.
Using an event study of U.S.-listed firms, we examine how media reach conditions the stock market reactions to adverse environmental, social, and governance (ESG) news across firms with different ESG performance and industry affiliations. On average, we find that a one-unit increase in media reach is associated with a decrease of 0.13 percentage points in cumulative abnormal returns, indicating an economically meaningful valuation effect. Further analysis shows that this effect is mainly concentrated among low-ESG firms in controversial industries. For high-ESG firms in these industries, media reach makes stock price declines significantly less severe than for low-ESG firms, indicating a media reach insurance effect. However, unless adverse news receives the highest-reach media coverage, we do not find evidence that high ESG performance provides an overall insurance effect. By identifying media reach as a key moderator, this study refines the ESG insurance hypothesis and clarifies when markets value ESG performance.
The shape of a graph arising from the covariation of variables is a crucial idea in reasoning about functions and graphs. Students' perspectives on graph shape may foreground visual features and consider the shape to be a fixed property of the function (static graphical shape thinking). In contrast, students can perceive the graph as a trace of covarying quantities, through which its shape arises (emergent graphical shape thinking). It is of interest to understand how these perspectives are supported and promoted by teachers in classroom discourse. We present findings from a study of classroom discourse in which we used systemic functional linguistics (SFL) to identify features of how teachers and students described graphs. We identified informal but vivid descriptions of graphs that may have affordances for, and even foreground, emergent graphical shape thinking.
NASA's Curiosity rover is exploring a 5 km tall sedimentary mound that is hypothesized to record the transition from a warm and wet (phyllosilicate-rich) to a cold and drier (sulfate-rich) Mars. Evidence of magnesium sulfate-bearing rock has shown that Curiosity has crossed through this phyllosilicate-sulfate transition. Recently, Curiosity arrived at the Amapari Marker Band, a darker, indurated unit that can be traced laterally for tens of kilometers in orbiter images. Here, Curiosity found evidence for a very broad lake, and bedforms interpreted as wave-ripple laminated sedimentary rock that likely was deposited in shallow water in the explored location, before becoming a deeper lake. These rocks are enriched in Fe, Mn, and Zn which has major implications for groundwater paleohydrology in Gale crater. Three formation hypotheses are considered: concretion formation during early diagenetic alteration of shallow lake sediments, laterization or leaching of the sediments, and addition of Fe, Mn, and Zn by a mildly acidic and reducing groundwater interacting with a redox and/or pH front in a stratified lake. The preferred interpretation of the metal enrichments within the Amapari Marker band sedimentary rocks is that they formed in a shallow water environment at a redox and/or pH front within the ripple unit, which drove precipitation and concentration of metals. If the enrichments are due to groundwater alteration, these processes could link subsurface and surface environments. Water and the presence of high amounts of redox sensitive elements and other metals are favorable indicators for habitability.
This article presents two empirical studies investigating the extent to which general English proficiency (GEP) and selected learner dispositions in online learning maintain their predictive utility for academic success in English-medium instruction (EMI) contexts in T & uuml;rkiye across the pre-pandemic, pandemic, and post-pandemic periods. Both studies sampled engineering students from a large public university, with Study 1 involving 474 participants and Study 2 including 460. Study 1 examined the predictive roles of GEP, online learning readiness, beliefs, and satisfaction during the pre-pandemic and pandemic periods. Findings showed that GEP was a significant predictor of academic success before the pandemic, but this predictive relationship was statistically disrupted during the pandemic period. Study 2 extended the analysis to the post-pandemic context, where EMI courses were delivered both face-to-face and online. Results revealed a reinstatement of GEP's predictive power in face-to-face EMI settings, while readiness, beliefs, and satisfaction with online learning were stronger predictors in online courses. This fluctuation illustrates a 'passing cloud effect', in which the predictive weight of language proficiency temporarily wanes under extraordinary contextual conditions but resurfaces when structured environments return. Based on the findings, several pedagogical implications are provided, and some relevant suggestions are made, underscoring the fluctuating nature of academic success in EMI.
