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Abstract Phytoplankton blooms in coastal oceans can be beneficial to coastal fisheries production and ecosystem function, but can also cause major environmental problems 1,2 —yet detailed characterizations of bloom incidence and distribution are not available worldwide. Here we map daily marine coastal algal blooms between 2003 and 2020 using global satellite observations at 1-km spatial resolution. We found that algal blooms occurred in 126 out of the 153 coastal countries examined. Globally, the spatial extent (+13.2%) and frequency (+59.2%) of blooms increased significantly ( P  < 0.05) over the study period, whereas blooms weakened in tropical and subtropical areas of the Northern Hemisphere. We documented the relationship between the bloom trends and ocean circulation, and identified the stimulatory effects of recent increases in sea surface temperature. Our compilation of daily mapped coastal phytoplankton blooms provides the basis for global assessments of bloom risks and benefits, and for the formulation or evaluation of management or policy actions. 

We investigate how a collaborative software development paradigm in the workplace can be adapted for collaborative project-based learning in the classroom. The paradigm, called Mob Programming, where a group of co-located developers work on one problem concurrently, inspires Online Mob Programming which structures groups of 3-6 students collaborating online, in a platform integrated with automated support for role rotation. Results from this study comparing OMP scaffolding with self-organization in a university computer science course shows OMP scaffolds help students adopt OMP roles without a significant drop in group product quality. 

This paper reports on work adapting an industry standard team practice referred to as Mob Programming into a paradigm called Online Mob Programming (OMP) for the purpose of encouraging teams to reflect on concepts and share work in the midst of their project experience. We present a study situated within a series of three course projects in a large online course on Cloud Computing. In a 3x3 Latin Square design, we compare students working alone and in two OMP configurations (with and without transactivity-maximization team formation designed to enhance reflection). The analysis reveals the extent to which grading on the produced software rewards teams where highly skilled individuals dominate the work. Further, compliance with the OMP paradigm is associated with greater evidence of group reflection on concepts and greater shared practice of programming. 

Abstract A late Mesoproterozoic detrital zircon (DZ) age population, which was previously considered diagnostic of a link between the Lhasa terrane and northwest Australia, occurs in other Gondwanan components, thus obscuring the paleogeographic position of the Lhasa terrane in Gondwana. Here we compiled large‐n(n ≥ 300) DZ U‐Pb data from the Lhasa terrane and potential source regions in various proposed reconstructions, and attempted to synthesize the Lhasa DZ age spectra through DZ mixing modeling. Our modeling results support the Permo‐Carboniferous Lhasa terrane having received sediment from NW Australia (mainly the Perth basin) rather than India or Africa. This, in combination with stratigraphic and paleontological evidence from the northern margin of eastern Gondwana positions the Paleozoic Lhasa terrane adjacent to the boundary between Australia and India. This study suggests that the DZ mixing modeling method based on large‐nDZ data can be used effectively for constraining paleogeographic reconstruction of continents. 

Abstract The chemical composition of the deep continental crust is key to understanding the formation and evolution of the continental crust. Constraining the chemical composition of present‐day deep continental crust is, however, limited by indirect accessibility. This paper presents a modeling method for constraining deep crustal chemical structures from observed crustal seismic structures. We compiled a set of published composition models for the continental crust to construct functional relationships between seismic wave speed and major oxide content in the crust. Phase equilibria and compressional wave speeds (V_P) for each composition model were calculated over a range of depths and temperatures of the deep crust. For conditions within the alpha(α)‐quartz stability field, robust functional relationships were obtained betweenV_Pand major oxide contents of the crust. Based on these relationships, observedV_Pof the deep crust can be inverted to chemical compositions for regions with given geotherms. We provide a MATLAB code for this process (CalcCrustComp). We apply this method to constrain compositions from deep crustalV_Pof global typical tectonic settings and the North China Craton (NCC). Our modeling results suggest that the lower crust in subduction‐related and rifting‐related tectonic settings may be more mafic than platforms/shields and orogens. The lowV_Psignature in the deep crust of the NCC can be explained by intermediate crustal compositions, higher water contents, and/or higher temperatures. The chemical structure obtained by this method can serve as a reference model to further identify deep crustal features.