Revised Generalized System of Preferences: Instant Replay or a Real Change

This article will discuss in detail the GSP in the United States. Ini- tially, it will examine the salient features of the original GSP program and subsequently the legislative hearings culminating in the extension of the GSP program. Finally, the article will explore the renewed version of the GSP and discuss its application

Revised Generalized System of Preferences: Instant Replay or a Real Change

This article will discuss in detail the GSP in the United States. Ini- tially, it will examine the salient features of the original GSP program and subsequently the legislative hearings culminating in the extension of the GSP program. Finally, the article will explore the renewed version of the GSP and discuss its application

Enzymatic Modification of Granular Potato Starch Using Isoamylase—Investigation of Morphological, Physicochemical, Molecular, and Techno‐Functional Properties

Granular potato starch is modified using the debranching enzyme isoamylase. The modification is performed in aqueous suspension (40% w/w) at 35 °C by grading the volume (100, 250, and 400 µL/50 g of starch, 200 U · mL−1) of enzyme solution added. The starch products obtained are comprehensively investigated in terms of morphological (scanning electron microscopy), structural (X‐ray diffraction), thermal (differential scanning calorimetry), techno‐functional (solubility, hot paste viscosity, gel strength), and molecular properties (size exclusion chromatography‐multi angle laser light scattering‐differential refractive index detection). The granular integrity is basically preserved after modification and a molecular degradation predominantly of the amylopectin by debranching is proved. However, a slight reduction of the weight average molar mass of the amylose fraction is found too. In addition, the intended partial molecular degradation of the starch polysaccharides, the effect of the preparation procedure including washing with ethanol and grinding impacts several starch characteristics conspicuously.TU Berlin, Open-Access-Mittel – 202

Influence of abiotic and biotic factors on benthic marine community composition, structure and stability: a multidisciplinary approach to molluscan assemblages from the Miocene of northern Germany

The Miocene mica‐clay deposits of Groß Pampau (northern Germany) are well known for their diverse assemblages of marine mammals. Despite numerous systematic and biostratigraphic studies, an in‐depth palaeoecological analysis of its molluscan assemblages and a comprehensive palaeoenvironmental reconstruction are lacking. Here, we integrate new faunal, sedimentological and geochemical data to reconstruct the marine palaeoecosystem of the Upper Miocene sedimentary succession of Groß Pampau, and to identify the drivers controlling the composition, ecological structure and temporal dynamics of its macrobenthic molluscan assemblages. Fossil evidence, coupled with analyses of clay mineral composition, grain size distribution and geochemical data (total organic carbon, total nitrogen, δ13C, δ18O, δ15N of sediment and shells), suggests a warm–temperate, mesotrophic, low‐energy, offshore marine setting mostly below storm wave base and a pronounced surface‐to‐bottom water temperature gradient. Low variability in sedimentological and geochemical signals indicates generally stable physicochemical conditions, whereas the occurrence of the opportunistic species Varicorbula gibba suggests occasionally unfavourable bottom conditions, possibly related to transient hypoxia. Canonical correspondence analysis indicates that the distribution of molluscan assemblages correlates with total organic carbon and nitrogen content, suggesting organic matter availability at the sea floor as a controlling factor. A pattern of repetitive punctuated stasis of molluscan assemblages is defined by the temporal persistence in taxonomic and ecological composition, occasionally interrupted by shifts to a different faunal configuration. We suggest that both stable environmental conditions and biotic interactions (i.e. the top‐down control exerted by carnivorous gastropods and environmental modification by ubiquitous burrowing deposit feeders) probably contributed to the observed temporal stability.Gemeinnützige Sparkassenstiftung Lübeckhttps://doi.org/10.5061/dryad.0p2ngf25

Analytical data of bulk geochemistry of sandstone samples from the Enticho Sandstone and the Edaga Arbi Glacials (Palaeozoic, Ethiopia)

We compare Ethiopian glaciogenic sandstone of the Late Ordovician and Carboniferous–Permian Gondwana glaciations petrographically and geochemically to provide insight into provenance, transport, and weathering characteristics. Although several studies deal with the glacial deposits in northern Africa and Arabia, the distribution of ice sheets and continent-wide glacier dynamics during the two glaciations remain unclear. Provenance data on Ethiopian Palaeozoic sedimentary rocks are scarce. The sandstones of the Late Ordovician glaciation are highly mature with an average quartz content of 95% and an average chemical index of alteration of 85, pointing to intense weathering and reworking prior to deposition. No evidence for sediment recycling was found. In contrast, the Carboniferous–Permian glaciogenic sandstones are less mature with an average quartz content of 75%, higher amounts of feldspar and rock fragments and a chemical index of alteration of 62. Trace and rare earth element concentrations indicate a higher input of juvenile material, most probably from proximal sources. Comparison with stratigraphically corresponding formations in Saudi Arabia shows similar geochemical patterns for the Upper Ordovician, but major differences in the Carboniferous–Permian. This supports previous assumptions of a large, uniform sediment dispersal system during the Late Ordovician glaciation, in which a combination of long transport paths and exceptionally strong weathering prior to the glaciation produced mature sandstone. During the Carboniferous–Permian, the glacial systems seem to have been more localised and glacial abrasion exposed fresh basement material.Final published dataset from the dissertatio

U-Pb detrital zircon constraints on the depositional age and provenance of the dinosaur-bearing Upper Cretaceous Wadi Milk formation of Sudan

Cretaceous continental deposits in Sudan have long been recognized as important archives of continental vertebrate fossils in central Africa. A number of different sedimentary units including the Wadi Milk, Shendi and Kababish formations from northern and central Sudan are known to yield dinosaur and other vertebrate fossils. The ages of these deposits are poorly constrained, and traditionally assumed to be of Albian to Santonian age based on biostratigraphic evidence. However, recent palynological analyses suggest a Campanian-Maastrichtian age for the Shendi Formation. Not only are the ages of these units poorly resolved; but stratigraphic correlations within and between them and similar aged units in central Africa, remains tenuous. To address these issues a detailed sedimentary fingerprinting and provenance analysis was conducted on the putatively correlative Shendi and Wadi Milk formations using sandstone petrography and a multifaceted detrital zircon investigation combining U-Pb geochronology, Lu-Hf isotope analysis and trace element geochemistry. The objective was to provide constraints on the age of deposition, sediment sources and paleofluvial drainage patterns. Based on laser ablation ICP-MS U-Pb detrital zircon geochronology of 18 sandstone samples (>1400 detrital zircons), we identified a population of six Late Cretaceous zircons from the Wadi Milk Formation yielding a maximum depositional age of 79.2 +/- 2.4 Ma (MSWD = 0.65, probability 0.62). Specifically, these data restrict the depositional age to Campanian or younger for the Wadi Milk Formation, which significantly refines our understanding of the age of this unit and its fauna. The Lu-Hf-isotope and trace element analyses of the remainder of the dated zircons show a provenance dominated by Neoproterozoic crustal sources and minor Paleoproterozoic and Archean sources for both units, which we interpret as being sourced from the Arabian-Nubian Shield to the south and southeast of the study area. These findings, coupled with the recently updated biostratigraphic age of the Shendi Formation, confirm that both units are correlative to one another and were probably deposited synchronously by north-north westerly flowing fluvial system draining into the Tethys Sea during the Late Cretaceous

Analytical data of U-Pb zircon chronology of sandstone samples from the Enticho Sandstone and the Edaga Arbi Glacials (Palaeozoic, Ethiopia)

Palaeozoic sedimentary successions in northern Ethiopia contain evidence for two Gondwana glaciations during the Late Ordovician and Carboniferous–Permian. We compare sediments of the two glaciations regarding their detrital zircon U–Pb ages. The main age group for both formations is Pan-African (c. 550–700 Ma). However, the remaining spectra are different: The Upper Ordovician–Lower Silurian Enticho Sandstone is characterised by a Stenian–Tonian (c. 1 Ga) zircon population. The Carboniferous–Permian Edaga Arbi Glacials contain a prominent c. 800 Ma population. The Stenian–Tonian zircons are likely derived from the centre of the East African Orogen and were supplied via the Gondwana super-fan system. This material was transported by the Late Ordovician glaciers and formed the Enticho Sandstone. Tonian (c. 800 Ma) zircons are abundant in the Ethiopian basement and represent the earliest formation stage of the southern Arabian–Nubian Shield. Glaciers of the Late Palaeozoic Ice Age must have cut deeply into the basement for efficient erosion. No recycling of the Enticho Sandstone by the Edaga Arbi Glacials took place on a grand scale — probably because sedimentation of the former was limited to northern Ethiopia, whereas the source area for the latter was to the south.Final second published dataset from the dissertatio

Analytical data of rutile and garnet chemistry of sandstone samples from the Enticho Sandstone and the Edaga Arbi Glacials (Palaeozoic, Ethiopia)

We use heavy minerals and rutile and garnet chemical compositions to constrain the provenance of two glaciogenic sandstone formations that build up the Palaeozoic succession in Ethiopia. The heavy mineral assemblage of the Upper Ordovician–Lower Silurian Enticho Sandstone is dominated by ultra-stable minerals, implying high maturity of the sediment. Variable amounts of garnet are present as well. The Carboniferous–Permian Edaga Arbi Glacials contain mainly less stable heavy minerals, such as garnet and apatite, suggesting little chemical alteration. A combination of magmatic and metamorphic source rocks is likely for both formations. Rutile and garnet chemistry point to mainly amphibolite-facies and to a lesser extent granulite-facies metamorphic source rocks with generally slightly higher metamorphic temperatures for detrital heavy minerals in the Enticho Sandstone. We conclude that the Enticho Sandstone is mainly the product of reworked mature Cambrian–Ordovician sediment, which may have been supplied via the Gondwana super-fan system. Locally, glaciers of the Late Ordovician glaciation eroded fresh basement material, delivering the garnet. For the Edaga Arbi Glacials, a rather proximal provenance is likely. The potential source area is the southern hinterland, where Precambrian low-to higher grade metamorphic rocks of the Arabian–Nubian Shield occur at the transition to the Mozambique Belt.Final thirt published dataset from the dissertatio

A comparative study of total organic carbon-δ13C signatures in the Triassic–Jurassic transitional beds of the Central European Basin and western Tethys shelf seas

Stratigraphic studies are an integral component in understanding the chronology of events that led to the end-Triassic mass extinction, by resolving causal relationships between environmental upheavals and biotic response. Successful correlation of Triassic–Jurassic (Tr–J) successions is complicated by the disappearance of macro-fossils that are otherwise central components in stratigraphic studies. This problem is exacerbated in multiple Tr–J sections situated in Europe, where the so-called “Event Beds” – assumed to demarcate the extinction interval – are virtually devoid of fossils. An alternative stratigraphic approach entails the reconstruction of carbon isotope records, where stratigraphic fluctuations in carbon isotope composition are considered to track changes in the global biogeochemical carbon cycle. The predominance of carbonate-lean sections has prompted the reconstruction of total organic carbon (TOC)-based carbon isotope records. However, bulk rock derived TOC is the diagenetically stabilized remnant of organic components that accumulated on the sea floor, and which can originate from multiple sources. In this study, we assess long-term TOC-based carbon isotope trends at two sites: Bonenburg (Central European Basin) and Kuhjoch (the Tr–J Global Stratotype Section and Point; western Tethys shelf seas). We focus on the TOC 13C-enrichment of the Event Beds with the aim of deciphering stratigraphic fluctuations in relation to their main driver (the exogenic carbon pool versus organic matter source changes). By studying the systematic co-variance of several sedimentary parameters (TOC, total nitrogen [TN], and the palynomorph composition), we infer that the TOC composition is possibly characterized by insignificant organic matter source changes in terms of the marine and terrestrial organic carbon contributions. By contrast, a clay mineralogical shift to more K-depleted minerals as well as the elevated occurrence of wood fragments in the Event Beds suggest a terrestrial organic matter source shift from immature substrates to substrates predominated by “pre-aged” or “fossil organic matter” under a changing continental weathering regime. This outcome urges for reservations when interpreting TOC-based carbon isotope records in terms of global C-cycle perturbations, especially when coinciding with lithological and mineralogical changes. On a more positive note, the shift towards positive carbon isotope values appears to be a recurring feature, possibly testifying to a globally significant climate-controlled weathering regime shift