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Mutations in a Plasmodium de-ubiquitinase UBP1 have been linked to antimalarial drug resistance. However, the UBP1-mediated drug-resistant mechanism remains unknown. Through drug selection, genetic mapping, allelic exchange, and functional characterization, here we show that simultaneous mutations of two amino acids (I1560N and P2874T) in the Plasmodium yoelii UBP1 can mediate high-level resistance to mefloquine, lumefantrine, and piperaquine. Mechanistically, the double mutations are shown to impair UBP1 cytoplasmic aggregation and de-ubiquitinating activity, leading to increased ubiquitination levels and altered protein localization, from the parasite digestive vacuole to the plasma membrane, of the P. yoelii multidrug resistance transporter 1 (MDR1). The MDR1 on the plasma membrane enhances the efflux of substrates/drugs out of the parasite cytoplasm to confer multidrug resistance, which can be reversed by inhibition of MDR1 transport. This study reveals a previously unknown drug-resistant mechanism mediated by UBP1 through altered MDR1 localization and substrate transport direction in a mouse model, providing a new malaria treatment strategy. Here, the authors show that two mutations in the Plasmodium de-ubiquitinase UBP1 alter the ubiquitination level, membrane localization, and ligand transport direction of multidrug resistance transporter 1 (MDR1), leading to multiple drug resistances. [ABSTRACT FROM AUTHOR]

SAC305-XBi (X = 0, 2) solder ribbons were prepared by two-roll rapid solidification technology. The microstructure, phase composition, melting characteristics, wettability and Cu/Solder/Cu joint interface microstructure, shear strength, and fracture morphology of the solder were investigated in this work. The experimental results show that the addition of 2.0 wt% Bi to the rapidly solidified SAC305 solder, the β-Sn were fine equiaxed crystal and the (Ag3Sn + Cu6Sn5) intermetallic compounds were uniformly distributed as tiny granules on the β-Sn matrix. The microstructure was refined and the compositions were evenly distributed. Rapid solidification increases the limit of Bi solid solution. The addition of Bi reduced critical nucleation radius, critical nucleation energy, and the nucleation undercooling of structure, which promoted nucleation. Ultimately, compared to the rapidly solidified SAC305 solder, the melting temperature was lower, the spreading areas enhanced about 40.0%, and the wettability was improved. The thickness of the IMC layer of the joint interface decreased approximately 21.6%, and the shear strength increased. [ABSTRACT FROM AUTHOR]

Sn–58Bi–1Ag solder ribbon was prepared by twin-roll rapid solidification technology, and the ultrasonic soldering process was used to prepare Cu/Sn–58Bi–1Ag/Cu linear solder joints. Electron probe microanalysis (EPMA) and energy dispersive X-ray spectroscopy (EDS) were used to study the interface morphology of intermetallic compounds (IMC), Bi segregation, and solder joint matrix microstructure evolution with the current density of 1 × 104A/cm2 (25 °C). The result shows that the morphology of the anode IMC layer changes from scallop-like to hilly-like and then to flat-plate-like with the electrification time, and the thickness of IMC layer increases gradually. Bi is segregated toward the anode to form a Bi-rich layer. The cathode IMC layer is changed from a scallop to a zigzag, and its thickness is firstly increased and then decreased. The Sn is segregated toward the cathode to finally form a β-Sn-rich layer. Coarsening of eutectic microstructure (β-Sn+Bi) in solder joint matrix was caused by prolonged time. Based on linear fitting, the kinetic index n of the IMC layer of the anode and cathode is 0.432 and 0.491, respectively, and the growth mechanism is supposed to be volume diffusion. Ultrasonic soldering techniques can refine the Bi phase and increase the solubility of Bi in β-Sn, which slows down the formation of Bi-rich layers. The addition of Ag forms wedge-shaped and granular Ag3Sn intermetallic compounds, which hinders the growth of the Bi-rich layer and the Cu6Sn5 IMC, thus effectively inhibiting the electromigration process. [ABSTRACT FROM AUTHOR]

Reconstruction of monsoon evolution in the tropical Indian Ocean and evaluation of its influence on large-scale ocean circulation and sea-air interaction processes can help us understand climate driving mechanisms. Herein, we used a gravity core SO184-10043 to present the marine sedimentary record from the southernmost Sumatra, spanning the past 35 kyr. The age model is well constrained by 12 accelerator mass spectrometry (AMS) radiocarbon dates determined in mixed planktic foraminifera. We also measured sediment grain size and major and trace elements to reconstruct the variations in hydrodynamic conditions and chemical weathering intensity. These data were then used to reveal the evolution of the northwest (Indonesian) monsoon system over the past 35 kyr. The results showed that both monsoon current and chemical weathering coincided with summer insolation in the Northern Hemisphere and responded to glacial-interglacial climate changes in the northern Atlantic. Higher grain-size values of sensitive components, increased chemical index of alteration (CIA), and Ba/Sr ratios, together with lower CaO/MgO ratios, reflect a stronger monsoon current and chemical weathering during the late marine isotope stage 3 and Holocene. Higher intensity of chemical weathering might be attributed to a stronger northwest monsoon carrying warm and moist air from the Asian continent to Indonesian waters. Lower values of sensitive components, CIA, and Ba/Sr, along with higher CaO/MgO values, reveal a weaker monsoon current and lower intensity of chemical weathering during the last glaciation-deglaciation phase, which was controlled by a weaker monsoon system. At a millennial timescale, cold events occurred during the following intervals: 30–26 ka BP, Heinrich Stadial 1 (HS1; 18–15 ka BP), Last Glacial Maximum (LGM; 23–18 ka BP), Younger Dryas (YD; 11–10 ka BP), and 8.2 ka BP. The same cold events were identified from core SO184-10043, indicating a perfect match with climatic cooling in the Northern Hemisphere. We also observed periodicities of ~ 7.9 ka, 3.0–3.1 ka, 2.2–2.3 ka, and ~ 1.0 ka in our core records. These periodicities are coincident with solar-induced climate changes and support the hypothesis that monsoon evolution in the tropical Indian Ocean during the late Pleistocene coincided with the climate change in the Northern Hemisphere. [ABSTRACT FROM AUTHOR]

Heavy metals (Sc, Cr, Co, Ni, Cu, Ga, Ge, Nb, Mo, Cd, In, Hf, Ta, W, Tl, Pb, Bi, Th, and U) in the surface sediments of the Ganges-Brahmaputra-Meghna (GBM) river system of the Bengal Basin (BB) were measured to evaluate the heavy metal contamination and anthropogenic influence. The average concentration levels of most of the heavy metals (except Mo and Tl) were above the average crustal and shale values. Contamination indices, including the contamination factor, pollution load index, enrichment factor, and geo-accumulation index, and multivariate statistical analyses indicated that the GBM is slightly polluted by heavy metals with some considerable pollution from Bi, Th, Ta, Cd, Nb, Pb, In, and U. Among the four individual rivers, the Brahmaputra River and Ganges-Brahmaputra (GB) confluence river sediments contain higher heavy metal concentrations than do the Ganges and Meghna Rivers, which may be caused by the effects of local municipal discharge, industrial or urban wastes, and ferry crossing activities. [ABSTRACT FROM AUTHOR]

Lithogenic grain-size, geochemical elements of core sediments from the central Bay of Bengal (BoB) were analyzed to identify sediment provenance and explore the regional "source-sink" processes since 25 ka. Based on the geochemical compositions of core BoB-88, relative contributions of three end-member sources (Himalayan, Myanmar, Indian Peninsula) were calculated and support the general understanding that Himalayan sources were dominant since the last glacial period, which could reach 70% on average in our study. However, sediments from the Indian Peninsula and Myanmar also contributed nonnegligible materials to the central BoB since 25 ka, especially the former shows an obvious increase since 7.5 ka, which was neglected in the previous studies. To trace the sedimentary processes of different provenance terrigenous materials and reveal their response to climate changes, four typical stages with obvious provenance percent variation, including the Last Glacial Maximum period (LGM), Heinrich 1 (H1), Early Holocene Climate Optimum (EHCO), and mid-late Holocene period, were highlighted and discussed. Sea-level change played a dominant role in the glacial-interglacial scale by controlling the transition of deposition center between the shelf/subaquatic delta and the Bengal Fan, especially for sediment from the Himalayan source, exerting influence on contributions from different provenance end-members between the Holocene and the last glacial period. The opposite directions of the southwest and northeast monsoon current in the BoB have a significant influence on the transfer of the Indian Peninsula and Myanmar materials to the studied core, which led to an increase of up to 11% than the average of the Indian Peninsula and a decrease of up to 9% than the average of the Myanmar source during the Holocene. The balance between sea level (limited transport to the deep sea) and ISM (improved erosion production and output to the BoB) during the mid-late Holocene period maintained the stability of Himalayan source percent. Due to the control of the ISM variations, the Himalayan source showed a decrease of up to 20% and 21% than average during the LGM and H1 period, respectively, and an increase of up to 14% than average during the EHCO. The Myanmar source exhibited fluctuations around the average value during the LGM period, but an obvious increase of up to 21% during the H1 period and a decrease up to 8% during the EHCO, while the Indian Peninsula source percent showed little variations during the LGM and H1, but a decrease of up to 6% during the EHCO. Obvious 1/4 processional and millennial periodic changes (5.0 kyr and 1.1 kyr) of contribution proportions from three end-members provide additional evidences for the climate control on the regional source-sink processes and proved the controlled mechanisms of the orbital parameters and possible influence from the solar activity on millennial scales. [ABSTRACT FROM AUTHOR]

The effects of Ag on the microstructure of solder matrix and shear strength of solder joint were studied. The Sn–58Bi solder ribbons were prepared by rapid solidification. The eutectic structure (β-Sn + Bi) was significantly refined by adding 1.0 wt% Ag to the Sn–58Bi solder. The refinement mechanism was investigated with a differential scanning calorimetry. The result showed that the addition of Ag reduced the nucleation undercooling of structure, which promoted the nucleation. In addition, the metastable phase particles of Ag6.7Sn formed during rapid solidification were dispersed at the Bi phase boundary, which hindered the growth of Bi phase. With 1.0 wt% Ag, the shear strength of Sn–58Bi solder joint increased by 13.3%. The Bi phase was found to be reduced in size and passivated by adding Ag, and it resulted in more phase boundaries and hindered the crack propagation during the stretching process. Moreover, the second phase particles of Ag3Sn formed after brazing and remelting had dispersion strengthening effect. However, the addition of Ag did not change the fracture mode of rapidly solidified Sn–58Bi solder, which was still intergranular brittle fracture. [ABSTRACT FROM AUTHOR]

The biogenic silica of sediment samples from Core CJ01-185 which is collected from the eastern India Ocean off the Sunda Strait is analyzed to evaluate the impact of the opening of the Sunda Strait on a paleoproductivity evolution. The new results indicate that the biogenic silica mass values of Core CJ01-185 show the lowest 0.86% in the last glacial period, and reach its maxima of 1.89% in the late Holocene. Furthermore, the biogenic silica mass accumulation rate (MARBSi) values also vary with much higher during the late Holocene than during the last glaciation. The input of additional terrigenous materials from the Java Sea has enhanced the paleoproductivity and increased the biogenic silica mass and MARBSi values after the opening of the Sunda Strait. It is suggested that the paleoproductivity in the study area is mainly influenced by the southeast monsoon and upwelling before the opening of the Sunda Strait. However, the paleoproductivity is dominated by the terrigenous materials input other than by the southeast monsoon or upwelling in the Holocene. [ABSTRACT FROM AUTHOR]

The effects of Bi on the microstructure of Sn-3.5Ag eutectic solder ribbon prepared by rapid solidification was investigated by optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. Bi refines the primary β-Sn phase and eutectic structure. The mechanism was investigated using differential scanning calorimetry and classical nucleation theory, respectively. The results show that the primary β-Sn phase and eutectic structure can be refined by adding a small amount of Bi. The refinement of the primary β-Sn phase is attributed to high compositional undercooling by Bi addition. The refinement of eutectic structure is caused by the reduction of critical nucleation radius and critical nucleation energy due to Bi segregation. With the addition of 0.3 wt.% Bi, the shear strength of solder joints increases by 12.15%. [ABSTRACT FROM AUTHOR]

Two kinds of Sn-3.5Ag eutectic solder ribbons of 0.13 mm thickness were prepared by a casting-rolling process and a rapid solidification process. The microstructure, phase constitution, melting characteristics, wetting behavior and soldering strength were compared using optical microscopy, scanning electron microscopy, x-ray diffraction, energy dispersive spectroscopy, differential scanning calorimetry and a MTS ceramic testing system. The results show that the microstructure of rapidly solidified solder is finer and more uniform, and the eutectic structure has a higher solid solubility and more homogeneous distribution of Ag in a Sn matrix. The solidus and liquidus temperature decreased, resulting in a 3.3% reduction of pasty range. In addition, the wettability and shear strength of the solder joints increased by 13.2% and 7.9%, respectively. [ABSTRACT FROM AUTHOR]

The major and trace elements in 110 surface sediment samples collected from the middle of the Bay of Bengal (mid-Bay of Bengal) are analyzed to investigate provenance. Si levels are highest, followed by Al, and the distributions of these two elements are identical. The average CIA* (chemical index of alteration) value is 72.07, indicating that the degree of weathering of the sediments in the study area is intermediate between those of sediments of the Himalayan and Indian rivers. Factor analyses and discrimination function analyses imply that the two main provenances are the Himalayan and the Indian continent. The inverse model calculation of the Ti-normalized element ratios of the Bay of Bengal sediments indicate an estimated average contribution of 83.5% and 16.5% from the Himalayan and peninsular Indian rivers to the study area, respectively. The Himalayan source contributes more sediment to the eastern part of the study area, whereas the western part receives more sediment from the Indian Peninsula than did the eastern part. The primary mechanisms for deposition of sediments in the study area are the transport of Himalayan matter by turbidity currents and river-diluted water and the transport of Indian matter to the study area by a surface circulation in the Bay of Bengal, particularly the East India Coastal Current. [ABSTRACT FROM AUTHOR]

Heavy metals (Cr, Cu, Zn, Cd, Pb, Hg, As), grain size, pH, Eh, total organic carbon, and total nitrogen of 157 surface sediments from the western Gulf of Thailand (GoT) were analyzed to determine the spatial distribution pattern, constraint factors, and pollution status of heavy metals in the surface sediments of the western GoT. The relationships of the heavy metals with sediment composition, pH, reduction/oxidation conditions, and total organic materials were evaluated by statistical analysis. Sediment compositions were the main factors controlling the concentrations of heavy metals as reported in many previous studies, while the hydrodynamic conditions, in particular the seasonal eddies, were an important factor controlling their distribution. Both sediment enrichment factor and geoaccumulation index were used to assess heavy metal accumulation. Only As reached the light contamination level near the upper GoT and the coastal area close to the Songkhla Province, due primarily to anthropogenic activities. [ABSTRACT FROM AUTHOR]

The sedimentary facies of the subaqueous Changjiang (Yangtze) River delta since the late Pleistocene was studied based on lithology and foraminifera analysis for two boreholes, CJK07 and CJK11, along with C dating. Four sedimentary facies were identified, namely fluvial, tidal flat, offshore, and prodelta facies. The fluvial sedimentary facies is comprised of fluvial channel lag deposits, fluvial point bar deposits, and floodplain deposits, showing a fining-upward sequence in general with no benthic foraminifera. A layer of stiff clay overlies the fluvial deposits in core CJK07, indicating a long-term exposure environment during the Last Glacial Maximum (LGM). During the postglacial sea-level rise around 13-7.5 cal ka BP, the tidal flat facies was deposited in core CJK11, characterized by abundant silt-clay couplets. Euryhaline species dominate the subtidal flat foraminiferal assemblages, while almost no foraminifera was found in the intertidal flat. The offshore environment was the major sedimentary environment when the sea level reached its highest level around 7.5 cal ka BP, with a maximum accumulation rate of 10 mm/a found in core CJK11. Prodelta sediments have been deposited in core CJK11 since ∼3 cal ka BP, after the formation of the Changjiang River delta. The difference in sedimentary facies between core CJK07 and CJK11 is due to their location: core CJK07 was in an interfluve while core CJK11 was in an incised valley during the LGM. Furthermore, AMS 14 C dating of core CJK07 shows poor chronological order, indicating that the sediments were reworked by strong tidal currents and that sediment deposited since ∼7.7 cal ka BP in core CJK07 was eroded away by modern hydrodynamic forces caused by the southward shift of the Changjiang River delta depocenter. [ABSTRACT FROM AUTHOR]

Glutamine synthetase catalyzes the synthesis of glutamine, providing nitrogen for the production of purines, pyrimidines, amino acids, and other compounds required in many pivotal cellular events. Herein, a full-length cDNA encoding Schistosoma japonicum glutamine synthetase (SjGS) was isolated from 21-day schistosomes. The entire open reading frame of SjGS contains a 1,095-bp coding region corresponding to 364 amino acids with a calculated molecular weight of 40.7 kDa. NCBIP blast shows that the putative amino acid of SjGS contains a classic β-grasp domain and a catalytic domain of glutamine synthetase. The relative mRNA expression of SjGS was evaluated in 7-, 13-, 21-, 28-, 35-, and 42-day worms of S. japonicum in the final host and higher expression at day 21, and 42 worms were observed. This protein was also detected in worm extracts using Western blot. Immunofluorescence studies indicated that the SjGS protein was mainly distributed on tegument and parenchyma in 28-day adult worms. The recombinant glutamine synthetase with a molecular weight of 45 kDa was expressed in Escherichia coli and purified in its active form. The enzyme activity of the recombinant protein was 3.30 ± 0.67 U.μg-1. The enzyme activity was highly stable over a wide range of pH (6-9) and temperature (25-40 °C) under physiological conditions. The transcription of SjGS was upregulated in praziquantel-treated worms at 2-, 4-, and 24-h posttreatment compared with the untreated control. As a first step towards the clarification of the role of glutamine synthetase in schistosome species, we have cloned and characterized cDNAs encoding SjGS in S. japonicum, and the data presented suggest that SjGS is an important molecule in the development of the schistosome. [ABSTRACT FROM AUTHOR]

The Inductively Coupled Plasma Optical Emission Spectrometer was used to analyze sediment samples collected from the Hangzhou Bay to determine major and trace elemental concentrations. Based on these concentrations, the study area can be classified into three geochemical provinces. Province I covers the northern Hangzhou Bay area and contains high concentrations of AlO, FeO, MgO, NaO, KO, MnO, Cr, Cu, Ni, Pb, V, Co and Zn. Province III is located in the western Hangzhou Bay, near the Qiantang River mouth, and contains high concentrations of SiO, NaO, PO, TiO, Cr, Sr, Zr. Province II is located in the middle and eastern Hangzhou Bay, with the medium concentrations of major and trace elements. The results also demonstrate that the grain size is the dominating factor controlling the spatial variations of elemental concentrations, and the Changjiang River (Yangtze River) and Qiantang River sediments play an important role in the distribution of these elements. Anthropogenic impact on heavy metal concentrations (especially Cr, Sr and Zr) can be detected in the surface sediments near the Qiantang River mouth. [ABSTRACT FROM AUTHOR]

Of all the parasitic diseases, malaria is the number one killer. Despite tremendous efforts in disease control and research, nearly a million people, primarily children, still die from the disease each year, partly due to drug resistance and the lack of an effective vaccine. Many parasite antigens have been identified and evaluated for vaccine development; however, none has been approved for human use. Antigenic variation, complex life cycle, and inadequate understanding of the mechanisms of parasite-host interaction and of host immune response all contribute to the lack of an effective vaccine for malaria control. In a recent search of genome-wide polymorphism in Plasmodium falciparum, several molecules were found to be recognized by sera from patients infected with the P. falciparum parasite. Here, we have expressed a 350-amino acid N terminus from one of the homologous candidate antigen genes from the rodent malaria parasite Plasmodium yoelii (Py01157, a putative dentin phosphorin) in bacteria and evaluated the immune response and protection generated after immunization with the recombinant protein. We showed that the recombinant protein was recognized by sera from both mice and humans infected with malaria parasites. Partial protection was observed after challenge with non-lethal P. yoelii 17XNL but not with the lethal P. yoelii 17XL parasite. Further tests using a full-length protein or the conserved C terminus may provide additional information on whether this protein has the potential for being a malaria vaccine. [ABSTRACT FROM AUTHOR]

Located at the collision boundary between the Philippine Sea Plate and the Eurasian Continental Plate, the island of Taiwan is generally recognized as an important example in the MARGINS Program Science Plan and 'source-to-sink' research because of its high tectonic activity, heavy rainfall and unique geography. Large suspended sediment loads are transported to the adjacent ocean by Taiwanese rivers every year, making Taiwan an important source of sediments into the adjacent seas and a natural laboratory for studying the systemic movement of fluvial sediments from source to sink. A detailed study on the clay mineral composition of surface sediments collected from the drainage basins of 12 Taiwanese rivers using X-ray diffraction methods was conducted. Our results indicated that the clay mineral assemblages consisted dominantly of illite (approximately 73%) and chlorite (approximately 24%), with lesser abundances of kaolinite (approximately 3%) and even lower levels of smectite from the Danshuei River sediments in northwestern Taiwan. The Jhuoshuei River sediments from western Taiwan contained clay mineral assemblages that consisted of illite (approximately 75%) and chlorite (approximately 25%), but they lacked kaolinite and smectite. In southwestern Taiwan, the clay mineral assemblages were dominated by illite (approximately 75%) and chlorite (approximately 23%), but had a low abundance of kaolinite (generally < 2%) and no smectite. The clay mineral assemblages in eastern Taiwan are obviously different from those in western parts of the island. The most noticeable difference is that the average abundance of chlorite in the Hualien River from eastern Taiwan was the highest (approximately 48%) of all the Taiwanese rivers. We concluded that, in general, the clay mineral assemblages in Taiwanese rivers were mainly composed of illite and chlorite with kaolinite and smectite being scarce, and these trends are different from those in China's mainland rivers. The clay mineral composition shown in this study was primarily determined by the properties of the bedrock, and the differential weathering intensities of the drainage area. The surface sediments in Taiwan's rivers showed a greater abundance of illite and chlorite because the outcropped rocks were mainly composed of Tertiary sedimentary rocks, especially sandstone, shale and slate, and show strong physical weathering. The relatively high relief and more abundant rainfall also caused the clay minerals in the fluvial sediments to be transported to the estuaries down rivers from the mountains and then delivered to the adjacent seas by currents and waves over a shorter time scale. [ABSTRACT FROM AUTHOR]

Paleoclimate record was revealed in Core MZ01 covering the mid-Holocene in age, located in the mud area of the inner continental shelf of the East China Sea. The ancient environment featured low-energy shallow sea shelf deposition formed mainly by coastal currents. The results show that temporal variation in geochemistry corresponds with the climate changes inferred from historical record. Relatively low MgO/AlO, CaO/KO and high AlO/NaO, KO/NaO, MnO/CaO values reflected a warm and humid climate in general, and vice versa. Therefore, these chemical indices could be applied to identify the variation of palaeoclimate in eastern China. The authors reconstructed the history of mid-Holocene climatic variation of the inner continental shelf of the East China Sea. From 8 300 a BP to 4 200 a BP, the climate was moderately warm and humid. From 4 200 a BP to 2 000 a BP, the climate turned cool and dry, and the regional climate frequently fluctuated in alternation of cool-dry periods (3 700 a BP, 2 850 a BP and 2 400 a BP) and warm-wet periods (3 250 a BP and 2 650 a BP). After 2 000 a BP, the climate of the study area gradually turned warm again, while the Little Ice Age, a cold event centered at around 250 a BP was indicated by those geochemical indices as mentioned above. [ABSTRACT FROM AUTHOR]

AMS14C dating and analysis of grain size, major elements and clay minerals were applied to Core MZ01 from the mud area on the inner shelf of the East China Sea. Based on the environmentally sensitive grain size, clay mineral and major element assemblages, the history of the East Asia winter monsoon since the mid-Holocene could be reconstructed. These three proxies, mean grain size (>9.71 µm), chemical index of alteration (CIA) and ratio of smectite to kaolinite in particular, show similar fluctuation patterns. Furthermore, 10 extreme values corresponding to the contemporary cooling events could be recognized since the mid-Holocene; these extreme values are likely to have been caused by the strengthening of the East Asia winter monsoon. The cooling events correlated well with the results of the δ 18 O curves of the Dunde ice core and GISP2, which therefore revealed a regional response to global climate change. Four stages of the East Asia winter monsoon were identified, i.e. 8300-6300 a BP, strong and unstable; 6300-3800 a BP, strong but stable; 3800-1400 a BP, weak and unstable; after 1400 a BP, weak but stable. [ABSTRACT FROM AUTHOR]

Effects of calcium addition and electromagnetic stirring on the microstructure of AZ91 magnesium alloy and refinement mechanism were investigated. The results show that calcium addition ranging from 0.1wt% to 0.3 wt% does not lead to formation of any new phases but cause the refi nement of as-cast microstructure.However, combined calcium alloying and electromagnetic stirring significantly decrease the grain size, change the morphologies of the β-Mg17Al12 phases,and reduce their volume percentage. The minimum grain size of AZ91 alloy is obtained in the case of the addition of 0.2 wt%Ca with exciting voltage of 100 V. The microstructural refi nement is attributed to the increase of the degree of undercooling and nucleation temperature of primary α-Mg phases on the basis of DTA analysis results. [ABSTRACT FROM AUTHOR]

Due to high productivity, periodic submersion, and rapid sedimentation rate, mangroves are important carbon sinks in tropical-subtropical coastal zones. Mangrove expansion can significantly enhance burial carbon storage in coastal zones and has been reported in many subtropical regions due to climate change in recent years. To better understand the response of carbon storage to climate change in subtropical-tropical coastal zones, it is necessary to estimate the change in burial organic carbon (OC) storage in mangroves undergoing expansion. In the Nanliu River estuary of South China, the total mangrove area has increased from 72 to 622 ha in recent decades. Based on a sedimentology study combined with historical satellite images analysis, the accumulation rate of burial OC in these mangroves is estimated to be 400–500 g‧m−2‧y−1, of which the part imported to the stratigraphy beneath the mangrove deposit layer is approximately 130 g‧m−2‧y−1. Globally, the reported OC accumulation rate is linearly correlated to the accretion rate in mangroves. The accumulation rate of mangrove burial OC estimated in this study is significantly higher than the corresponding value on this fitted curve, indicating that the OC accumulation rates may be underestimated in such mangroves because the OC imported to the lower root layer has been not been taken into account. Based on the estimated OC accumulation rate and the time-series data of the mangrove area, the increase in burial OC storage in the mangroves of the Nanliu River estuary from 1988 to 2018 is estimated at more than 35 Gg. This study provides an example of estimating soil OC storage increase in expanding mangroves, which can help us better understand the response of coastal carbon pool to climate change. [ABSTRACT FROM AUTHOR]

A correction to the article "Effects of Forming Processes on the Microstructure and Solderability of Sn-3.5Ag Eutectic Solder Ribbons as well as the Mechanical Properties of Solder Joints," by Shenga Liu and colleagues published in an issue of the journal is presented.