bluuebunny/crossref_metadata_2025 huggingface dataset:
Hawkeye
Authors: de Rond Mark
Published: December 2017

In this chapter, the author talks about a general surgeon he calls Hawkeye, whom he met during a weeklong surgical training course at the Royal College of Surgeons in London. Pre-deployment training involved five days practicing on human cadavers made up to resemble recipients of the war's signature wounds. The author describes Hawkeye as someone who has genuine concern for those put in his care, particularly the Royal Marines. He also discusses the three of four required pre-deployment courses: MOST, targeted specifically at surgeons and anesthetists, a Hospital Exercise (Hospex) staged in a near-perfect replica of the Role 3 hospital in Camp Bastion, but on a military base outside York, and designed to bring the entire hospital staff together; and a ten-day Operational Test and Evaluation Command (OPTEC) hosted at the Royal Navy base in Portsmouth and required for everyone about to deploy regardless of specialty or rank.
Apocalypse Now and Again
Authors: de Rond Mark
Published: December 2017

The author talks about the casualties of the day, two of whom died, seven had amputations, and five had major debridements. He begins by mentioning some of the books that he was given to read prior to deployment, including MASH by Richard Hooker, Unreasonable Behaviour by Don McCullin, What It Is Like to Go to War by Karl Marlantes, and Heart of Darkness by Joseph Conrad. According to the author, doctors, when not working, could often be seen watching Hollywood interpretations of modern warfare such as A Bridge Too Far, Apocalypse Now, The Deer Hunter, and Platoon. He says noise seems to be an important cue in both resus and theater. Where injuries require the input of several orthopodetic surgeons, a couple of general surgeons, anesthetists, and supporting staff, noise levels act as useful indicators. The author also cites patients who inflict self-harm, both Afghans and soldiers.
War Is Nasty
Authors: de Rond Mark
Published: December 2017

The author denounces the war because of the ugly psychological effects of war. He first describes some of the day's casualties in Camp Bastion, including a seven-year-old bilateral amputee, a fifteen-year-old shot in the chest by NATO troops after he failed to heed warning shots, and a U.S. marine who died on the operating table. He then wonders how surgeons and nurses are affected by nonstop exposure to death and dying and goes on to cite the psychological costs of war such as post-traumatic stress disorder (PTSD) and suicides among military personnel. He says exposure to the consequences of war was personally traumatic to the surgical team in Camp Bastion. The author concludes with an overview of the coping mechanisms used by the field hospital's medical staff in an attempt to protect themselves from psychological anguish, namely: “avoidance coping” and “escape coping.”
Switzerland
Authors: Sharman J. C.
Published: December 2017

This chapter traces how Switzerland has historically attracted such a huge share of foreign wealth. The coverage of kleptocrats' wealth in Switzerland and the various efforts to recover it is roughly divided into three sections. The first deals with the examples of Marcos of the Philippines, Abacha of Nigeria, and Montesinos of Peru over the period 1986–2005. The second part considers some failures, with coverage of “Baby Doc” Duvalier (Haiti), and Benazir Bhutto and Ali Asif Zardari (Pakistan). The third section analyzes the Arab Spring cases, with a brief mention of others involving incumbents in Uzbekistan and Malaysia, to assess the effects of preventive and remedial policy reforms introduced in response to earlier scandals.
Viking Friendship
Authors: Sigurdsson Jón Vidar
Published: December 2017

Friendship was the most important social bond in Iceland and Norway during the Viking Age and the early Middle Ages. Far more significantly than kinship ties, it defined relations between chieftains, and between chieftains and householders. This book explores the various ways in which friendship tied Icelandic and Norwegian societies together, its role in power struggles and ending conflicts, and how it shaped religious beliefs and practices both before and after the introduction of Christianity. The book details how loyalties between friends were established and maintained. The key elements of Viking friendship, it shows, were protection and generosity, which was most often expressed through gift giving and feasting. In a society without institutions that could guarantee support and security, these were crucial means of structuring mutual assistance. As a political force, friendship was essential in the decentralized Free State period in Iceland's history (from its settlement about 800 until it came under Norwegian control in the years 1262–1264) as local chieftains vied for power and peace. In Norway, where authority was more centralized, kings attempted to use friendship to secure the loyalty of their subjects. The strong reciprocal demands of Viking friendship also informed the relationship that individuals had both with the Old Norse gods and, after 1000, with Christianity's God and saints. Addressing such other aspects as the possibility of friendship between women and the relationship between friendship and kinship, the book concludes by tracing the decline of friendship as the fundamental social bond in Iceland as a consequence of Norwegian rule.
Introduction
Authors: Sigurðsson Jón Viðar
Published: December 2017

This introductory chapter provides an overview of friendship. Friendship exists in a state of constant flux, being shaped by and shaping other personal relationships. Thus, it cannot be studied in isolation of other social relations. Until about 1970, the idea of a strong kin group was central to the discussion of Norwegian and Icelandic society in the Viking Age and the high Middle Ages. The view was that a patriarchal kin-based organization united the social, judicial, political, and religious facets of society. The kin group possessed land in common and probably took care of the “individual kin-group member's need for protection, his lawful rights and his religious needs.” Over time there has been a shift in the debate in Iceland and Norway, from a focus on the kin-based society and the political institutions described in the law codes, toward the political culture and the role friendship played.
Friendship
Authors: Sigurðsson Jón Viðar
Published: December 2017

This chapter discusses the significance of friendship in the relationships between householders and chieftains in Iceland. There is little doubt that friendship was the most important social bond between chieftains and householders in Iceland during the period from about 870, when the first settlers disembarked on the newly discovered island, until the years 1262–64. These friendships included strong reciprocal demands. The chieftains were to protect the householders and their households, organize feasts for them, and give them gifts. In return, the chieftains received the householders' support in their conflicts. However, it was not simply the householders and chieftains who established friendships with each other. Chieftains established friendships among themselves, as did the householders.
Clerics and Friendship
Authors: Sigurðsson Jón Viðar
Published: December 2017

This chapter looks at relations of friendship among clerics. Friendship was as important for religious leaders as it was for their secular counterparts. They needed faithful supporters to enact their plans. Yet, in contrast to what have been seen in secular circles, friendship continued to play an important role among the clergy for the whole of the period from the middle of the eleventh century until the end of the thirteenth. The bishops, as the key element in the church hierarchy, were very powerful political players, not least attributable to their position within the Church hierarchy, their network of friends and connections, the wealth they controlled, and the position they held in society. Therefore, it was important for the secular leaders to control the election of bishops so that their friends and kinsmen were chosen.
Kinsmen and Friends
Authors: Sigurðsson Jón Viðar
Published: December 2017

This chapter studies the relationship between friendship and kinship. The difference between friendship and kinship was that relations of friendship were most often contracted willingly, unlike bonds of kinship that were established at birth. However, because of all the overlapping of family relationships and the limited support kin could give most people in conflicts, kinship took a back seat to friendship, except among the chieftain families. Indeed, there was no automatic support merely from bonds of kinship. Rather, these bonds had to be built up before one could expect any consideration. In other words, reciprocity is equally important in the relationships between kin as it was in friendships.
Friendship Loses Its Power
Authors: Sigurðsson Jón Viðar
Published: December 2017

This chapter assesses how the political development changed the political culture and reduced the importance of friendship. Friendship lost much of its significance in Iceland when the country became part of the Norwegian realm. The new administrative system turned the chieftain's role upside down. Chieftains now got their power from the king, who, in turn, got his power ostensibly from God. This meant that the chieftains no longer needed to build up their power base from below through protection, feasting, and gifts to householders. Now, as the king's officials, the chieftains were to prosecute the householders and possibly punish them, not help them in their conflicts.
Pragmatic Friendship
Authors: Sigurðsson Jón Viðar
Published: December 2017

This concluding chapter examines the three stages of friendship: establishment, development, and conclusion. The establishment of friendship was only the first step in a relationship between two parties. The contribution each party then made to the relationship determined its depth, importance and content. The key factor in friendships was loyalty. In a society without institutions that could guarantee support and security, it was crucial that a bond existed that created loyalty and provided assistance, and that was friendship. This is why it was such an important aspect of society in Norway and Iceland in the greater part of the period considered in this book. Given the lack of sources about the ending of a friendship, it is probable that most did not end until one of the friends died. In the relationship between chieftains and householders, if both parties fulfilled their obligations, the friendship would likely be lifelong.
Angered Spirits
Authors: High Mette M.
Published: December 2017

This chapter explores how people involved in gold mining rely on more than just knowledge of local geology and mining technologies in their search for gold. They also enter into relationships with new and dangerous spirit beings in order to attract and harness fortune (hishig). However, as they do this, ninjas are said to also come into contact with the misfortune of gold, which can be redirected onto others through ritual practices. With illnesses readily blamed on ninjas, they are subject to much suspicion and enmity. Examining local understandings of a transforming landscape, the chapter shows how the desire for subterranean wealth demands recognition of powerful spirit worlds.
Selling Hope and College
Authors: Posecznick Alex
Published: December 2017

It has long been assumed that college admission should be a simple matter of sorting students according to merit, with the best heading off to the Ivy League and highly ranked liberal arts colleges and the rest falling naturally into their rightful places. Admission to selective institutions, where extremely fine distinctions are made, is characterized by heated public debates about whether standardized exams, high school transcripts, essays, recommendation letters, or interviews best indicate which prospective students are worthy. And then there is college for everyone else. But what goes into less-selective college admissions? Ravenwood College was a small, private, nonprofit institution dedicated to social justice and serving traditionally underprepared students from underrepresented minority groups. To survive in the higher education marketplace, the college had to operate like a business and negotiate complex categories of merit while painting a hopeful picture of the future for its applicants. This book is a snapshot of a particular type of institution as it goes about the business of producing itself and justifying its place in the market. This book documents what it takes to keep such an institution open and running, and the struggles, tensions, and battles that members of the community tangle with daily as they carefully walk the line between empowering marginalized students and exploiting them.
Extraordinary Mediocrity
Authors: Posecznick Alex
Published: December 2017

This chapter presents a historical analysis of the American culture of meritocracy as manifested in education. Merit is most often understood as being a personal matter, as existing in individual personality traits such as competency, intelligence, and diligence—which are themselves rooted in cognition, biology, and morality. The chapter discusses how individuals make choices and take action, but do so within the confines of their cultural understandings and as these conform to the existing social order. Much of the work of educational institutions is therefore less concerned with teaching or learning, and more concerned with sorting or positioning everyone in relation to the others around them, and then in communicating that position to other institutions through a process that can be called credentialing.
How to Sell Hope and Mobility
Authors: Posecznick Alex
Published: December 2017

This chapter describes Ravenwood's position in the higher education market and the kinds of persuasive arguments that members of the community deploy to recruit new students every year. Corporatization in the university has brought the logic and language of markets to these processes, which align with the Jeffersonian paradigm of education and create a somewhat rigid interpretation of institutional mission and risk. Diversification of student enrollment is a safety net from fiscal risk but also reflects the potential watering down of institutional brand. Administrators are thus constantly balancing contradictory tensions in their attempts to secure fiscal security without sacrificing the mission or brand of the institution. Individual counselors also tackle similar propositions within the context of their own careers.
Why American Elections Are Flawed (and How to Fix Them)
Authors: Norris Pippa
Published: December 2017

The flaws in the American electoral process have become increasingly apparent in recent years. The contemporary tipping point in public awareness occurred during the 2000 election count, and concern deepened due to several major problems observed in the 2016 campaign, worsening party polarization, and corroding public trust in the legitimacy of the outcome. To gather evidence about the quality of elections around the world, in 2012 the Electoral Integrity Project was established as an independent research project based at Harvard and Sydney universities. The results show that experts rated American elections as the worst among all Western democracies. Without reform, these problems risk damaging the legitimacy of American elections—further weakening public confidence in political parties, Congress, and the U.S. government, depressing voter turnout, and exacerbating the risks of mass protests. This book describes several major challenges observed during the 2016 U.S. elections arising from deepening party polarization over basic voting procedures, the serious risks of hacking and weak cyber-security, the consequences of deregulating campaign spending, and lack of professional and impartial electoral management. This book outlines the core concept and measure of electoral integrity, the key yardstick used to evaluate free and fair elections. Evidence from expert and mass surveys demonstrate the extent of problems in American elections. The book shows how these challenges could be addressed through several practical steps designed to improve electoral procedures and practices. If implemented, the reforms will advance free and fair elections, and liberal democracy, at home and abroad.
Human viperin catalyzes the modification of GPP and FPP potentially affecting cholesterol synthesis
Authors: Mikulecky Pavel , Andreeva Elena , Amara Patricia , Weissenhorn Winfried , Nicolet Yvain , Macheboeuf Pauline
Published: December 2017

Viperin is a radical SAM enzyme that possesses antiviral properties against a broad range of enveloped viruses. Here, we describe the activity of human viperin with two molecules of the mevalonate pathway, geranyl pyrophosphate, and farnesyl pyrophosphate, involved in cholesterol biosynthesis. We postulate that the radical modification of these two molecules by viperin might lead to defects in cholesterol synthesis, thereby affecting the composition of lipid rafts and subsequent enveloped virus budding.
Mitochondrial dynamics, mitophagy and biogenesis in neonatal hypoxic‐ischaemic brain injury
Authors: Thornton Claire , Jones Adam , Nair Syam , Aabdien Afra , Mallard Carina , Hagberg Henrik
Published: December 2017

Hypoxic‐ischaemic encephalopathy, resulting from asphyxia during birth, affects 2–3 in every 1000 term infants and depending on severity, brings about life‐changing neurological consequences or death. This hypoxic‐ischaemia (HI) results in a delayed neural energy failure during which the majority of brain injury occurs. Currently, there are limited treatment options and additional therapies are urgently required. Mitochondrial dysfunction acts as a focal point in injury development in the immature brain. Not only do mitochondria become permeabilised, but recent findings implicate perturbations in mitochondrial dynamics (fission, fusion), mitophagy and biogenesis. Mitoprotective therapies may therefore offer a new avenue of intervention for babies who suffer lifelong disabilities due to birth asphyxia.
The structure of BrlR reveals a potential pyocyanin binding site
Authors: Raju Harikiran , Sundararajan Rukmini , Sharma Rohan
Published: December 2017

The transcriptional regulator BrlR from Pseudomonas aeruginosa is a member of the MerR family of multidrug transport activators. Studies have shown that BrlR plays an important role in the drug tolerance of P. aeruginosa in biofilms. The tolerance to drugs can be enhanced by 3′,5′‐cyclic diguanylic acid (c‐di‐GMP). In the present study, we analyze the apo structure of BrlR and the direct binding between GyrI‐like domain of BrlR and P. aeruginosa toxin pyocyanin. Furthermore, we show that pyocyanin can enhance the binding between BrlR and DNA in vitro. These findings suggest that BrlR can serve as the binding partner for both c‐di‐GMP and pyocyanin.
Large Differences in Global and Regional Total Soil Carbon Stock Estimates Based on SoilGrids, HWSD, and NCSCD: Intercomparison and Evaluation Based on Field Data From USA, England, Wales, and France
Authors: Tifafi Marwa , Guenet Bertrand , Hatté Christine
Published: December 2017

Soils are the major component of the terrestrial ecosystem and the largest organic carbon reservoir on Earth. However, they are a nonrenewable natural resource and especially reactive to human disturbance and climate change. Despite its importance, soil carbon dynamics is an important source of uncertainty for future climate predictions and there is a growing need for more precise information to better understand the mechanisms controlling soil carbon dynamics and better constrain Earth system models. The aim of our work is to compare soil organic carbon stocks given by different global and regional databases that already exist. We calculated global and regional soil carbon stocks at 1 m depth given by three existing databases (SoilGrids, the Harmonized World Soil Database, and the Northern Circumpolar Soil Carbon Database). We observed that total stocks predicted by each product differ greatly: it is estimated to be around 3,400 Pg by SoilGrids and is about 2,500 Pg according to Harmonized World Soil Database. This difference is marked in particular for boreal regions where differences can be related to high disparities in soil organic carbon concentration. Differences in other regions are more limited and may be related to differences in bulk density estimates. Finally, evaluation of the three data sets versus ground truth data shows that (i) there is a significant difference in spatial patterns between ground truth data and compared data sets and that (ii) data sets underestimate by more than 40% the soil organic carbon stock compared to field data.
Opposite Latitudinal Dependence of the Premidnight and Postmidnight Oscillations in the Electron Density of Midlatitude F Layer
Authors: Chen Gang , Wang Jin , Zhang Shaodong , Deng Zhongxin , Zhong Dingkun , Wu Chen , Jin Han , Li Yaxian
Published: December 2017

The dense observation points of the oblique‐incidence ionosonde network in North China make it possible to discover the ionospheric regional variations with relatively high spatial resolution. The ionosonde network and the Beijing digisonde are used to investigate the ionospheric nighttime oscillations in January and February 2011. The electron density enhancements occurring before and after midnight present the obvious opposite latitudinal dependence in the time‐latitude maps, which are composed by the differential critical frequency of F2 layer. The premidnight enhancements (PRMEs) appeared earlier in the north and then moved to south. The postmidnight enhancements (POMEs) did the opposite. The data analysis shows that the PRME was a part of the large‐scale traveling ionospheric disturbance (LSTID), which may be produced by gravity waves. The southward propagation of the LSTIDs is considered to form the positive latitudinal dependence of the wave peaks and troughs. The postmidnight F layer oscillation was composed by a single enhancement and a single decline following it. The westward electric field‐induced E × B drift, which pushed the F layer to lower altitudes with higher recombination loss, was most likely to compress the plasma and produce the POMEs. Along with the continuously dropping of the layer, the recombination loss exceeded the density increase due to the compression effect and then the electron density decline appeared.
Autumn Cooling of Western East Antarctica Linked to the Tropical Pacific
Authors: Clem Kyle R. , Renwick James A. , McGregor James
Published: December 2017

Over the past 60 years, the climate of East Antarctica cooled while portions of West Antarctica were among the most rapidly warming regions on the planet. The East Antarctic cooling is attributed to a positive trend in the Southern Annular Mode (SAM) and a strengthening of the westerlies, while West Antarctic warming is tied to zonally asymmetric circulation changes forced by the tropics. This study finds recent (post‐1979) surface cooling of East Antarctica during austral autumn to also be tied to tropical forcing, namely, an increase in La Niña events. The recent increase in La Niña conditions forces a Rossby wave into the Southern Hemisphere that increases anticyclonic circulation over the South Atlantic. The South Atlantic anticyclone is associated with cold air advection, weakened northerlies, and increased sea ice concentrations across the western East Antarctic coast, which has increased the rate of cooling at Novolazarevskaya and Syowa stations after 1979. This enhanced cooling over western East Antarctica is tied more broadly to a zonally asymmetric temperature trend pattern across East Antarctica during autumn that is consistent with a tropically forced Rossby wave rather than a SAM pattern; the positive SAM pattern is associated with ubiquitous cooling across East Antarctica, which is not seen in temperature observations after 1979. We conclude that El Niño–Southern Oscillation‐related circulation anomalies, particularly zonal asymmetries that locally enhance meridional wind, are an important component of East Antarctic climate variability during autumn, and future changes in tropical Pacific climate will likely have implications for East Antarctica.
Hydrometeorology as an Inversion Problem: Can River Discharge Observations Improve the Atmosphere by Ensemble Data Assimilation?
Authors: Sawada Yohei , Nakaegawa Tosiyuki , Miyoshi Takemasa
Published: December 2017

We examine the potential of assimilating river discharge observations into the atmosphere by strongly coupled river‐atmosphere ensemble data assimilation. The Japan Meteorological Agency's Non‐Hydrostatic atmospheric Model (JMA‐NHM) is first coupled with a simple rainfall‐runoff model. Next, the local ensemble transform Kalman filter is used for this coupled model to assimilate the observations of the rainfall‐runoff model variables into the JMA‐NHM model variables. This system makes it possible to do hydrometeorology backward, i.e., to inversely estimate atmospheric conditions from the information of river flows or a flood on land surfaces. We perform a proof‐of‐concept Observing System Simulation Experiment, which reveals that the assimilation of river discharge observations into the atmospheric model variables can improve the skill of the short‐term severe rainfall forecast.
Field‐Aligned Electrostatic Potentials Above the Martian Exobase From MGS Electron Reflectometry: Structure and Variability
Authors: Lillis Robert J. , Halekas J. S. , Fillingim M. O. , Poppe A. R. , Collinson G. , Brain David A. , Mitchell D. L.
Published: December 2017

Field‐aligned electrostatic potentials in the Martian ionosphere play potentially important roles in maintaining current systems, driving atmospheric escape and producing aurora. The strength and polarity of the potential difference between the observation altitude and the exobase (~180 km) determine the energy dependence of electron pitch angle distributions (PADs) measured on open magnetic field lines (i.e. those connected both to the collisional atmosphere and to the interplanetary magnetic field). Here we derive and examine a data set of ~3.6 million measurements of the potential between 185 km and 400 km altitude from PADs measured by the Mars Global Surveyor Magnetometer/Electron Reflectometer experiment at 2 A.M./2 P.M. local time from May 1999 to November 2006. Potentials display significant variability, consistent with expected variable positive and negative divergences of the convection electric field in the highly variable and dynamic Martian plasma environment. However, superimposed on this variability are persistent patterns whereby potential magnitudes depend positively on crustal magnetic field strength, being close to zero where crustal fields are weak or nonexistent. Average potentials are typically positive near the center of topologically open crustal field regions where field lines are steeper, and negative near the edges of such regions where fields are shallower, near the boundaries with closed fields. This structure is less pronounced for higher solar wind pressures and (on the dayside) higher solar EUV irradiance. Its causes are uncertain at present but may be due to differential motion of electrons and ions in Mars's substantial but (compared to Earth) weak magnetic fields.
Shifts in the Source and Composition of Dissolved Organic Matter in Southwest Greenland Lakes Along a Regional Hydro‐climatic Gradient
Authors: Osburn Christopher L. , Anderson Nicholas J. , Stedmon Colin A. , Giles Madeline E. , Whiteford Erika J. , McGenity Terry J. , Dumbrell Alex J. , Underwood Graham J. C.
Published: December 2017

Dissolved organic matter (DOM) concentration and quality were examined from Arctic lakes located in three clusters across south‐west (SW) Greenland, covering the regional climatic gradient: cool, wet coastal zone; dry inland interior; and cool, dry ice‐marginal areas. We hypothesized that differences in mean annual precipitation between sites would result in a reduced hydrological connectivity between lakes and their catchments and that this concentrates degraded DOM. The DOM in the inland lake group was characterized by a lower aromaticity and molecular weight, a low soil‐like fluorescence, and carbon stable isotope (δ13C‐DOC) values enriched by ~2‰ relative to the coastal group. DOC‐specific absorbance (SUVA254) and DOC‐specific soil‐like fluorescence (SUVFC1) revealed seasonal and climatic gradients across which DOM exhibited a dynamic we term “pulse‐process”: Pulses of DOM exported from soils to lakes during snow and ice melt were followed by pulses of autochthonous DOM inputs (possibly from macrophytes), and their subsequent photochemical and microbial processing. These effects regulated the dynamics of DOM in the inland lakes and suggested that if circumpolar lakes currently situated in cool wetter climatic regimes with strong hydrological connectivity have reduced connectivity under a drier future climate, they may evolve toward an end‐point of large stocks of highly degraded DOC, equivalent to the inland lakes in the present study. The regional climatic gradient across SW Greenland and its influence on DOM properties in these lakes provide a model of possible future changes to lake C cycling in high‐latitude systems where climatic changes are most pronounced.
Evidence for the Thermal Bleaching of Porites Corals From 4.0 ka B.P. in the Northern South China Sea
Authors: Xu Shendong , Yu Kefu , Tao Shichen , Wu Chung‐Che , Wang Yinghui , Jiang Wei , Wang Shaopeng , Shen Chuan‐Chou
Published: December 2017

Coral bleaching is becoming a serious issue for coral reefs under the stress of global warming. However, whether it has occurred in the past in times of thermal stress remains unclear. Moreover, an understanding of historic coral bleaching events would greatly improve our insight into the adaptive capabilities of corals under such stresses. It is known that Porites corals, a massive coral, have relatively high levels of symbiotic zooxanthellae and a strong thermal tolerance when compared with most other corals (and particularly branched corals). Thus, growth hiatuses and/or mortality surfaces of fossil Porites may be used to indicate past ecological or environmental stress events, such as severe bleaching. In this study, monthly geochemical and isotopic environmental proxies of four fossil Porites corals with well‐preserved growth hiatuses and mortality surfaces (aged 3,800–4,200 years before 2013 A.D.), collected from Wenchang fringing reef, Hainan Island, Northern South China Sea were analyzed. Specifically, the Sr/Ca, δ18O, and δ13C were measured with a monthly resolution for each sample. These environmental proxies were used to reconstruct the sea surface temperature (SST), sea surface salinity (SSS), and physiological activity of the coral at the time when the growth hiatuses and/or mortality surfaces occurred. These data were subsequently used to determine the causes of coral mortality and growth discontinuity in each case. The results show that growth hiatuses and mortalities mainly occurred in summer, with high SST (31–34°C) and SSS (32.8–38.4). In addition, abrupt negative shifts of 2–3‰ in δ13C were observed in almost all of the surfaces of growth hiatus and mortality, indicating a dramatically reduced level of photosynthetic activity in symbiotic zooxanthellae. Because of the above reasons, we conclude that the frequently observed mortality and growth discontinuity of Porites corals from the mid‐Holocene is evidence for thermal bleaching events in the past. That is, coral bleaching has occurred 3,800–4,200 years ago and is not a new phenomenon.
Soil Carbon Dynamics in Soybean Cropland and Forests in Mato Grosso, Brazil
Authors: Nagy R. Chelsea , Porder Stephen , Brando Paulo , Davidson Eric A. , Figueira Adelaine Michela e Silva , Neill Christopher , Riskin Shelby , Trumbore Susan
Published: December 2017

Climate and land use models predict that tropical deforestation and conversion to cropland will produce a large flux of soil carbon (C) to the atmosphere from accelerated decomposition of soil organic matter (SOM). However, the C flux from the deep tropical soils on which most intensive crop agriculture is now expanding remains poorly constrained. To quantify the effect of intensive agriculture on tropical soil C, we compared C stocks, radiocarbon, and stable C isotopes to 2 m depth from forests and soybean cropland created from former pasture in Mato Grosso, Brazil. We hypothesized that soil disturbance, higher soil temperatures (+2°C), and lower OM inputs from soybeans would increase soil C turnover and deplete C stocks relative to nearby forest soils. However, we found reduced C concentrations and stocks only in surface soils (0–10 cm) of soybean cropland compared with forests, and these differences could be explained by soil mixing during plowing. The amount and Δ14C of respired CO2 to 50 cm depth were significantly lower from soybean soils, yet CO2 production at 2 m deep was low in both forest and soybean soils. Mean surface soil δ13C decreased by 0.5‰ between 2009 and 2013 in soybean cropland, suggesting low OM inputs from soybeans. Together these findings suggest the following: (1) soil C is relatively resistant to changes in land use and (2) conversion to cropland caused a small, measurable reduction in the fast‐cycling C pool through reduced OM inputs, mobilization of older C from soil mixing, and/or destabilization of SOM in surface soils.
Electrode Work Function Engineering with Phosphonic Acid Monolayers and Molecular Acceptors: Charge Redistribution Mechanisms
Authors: Timpel Melanie , Li Hong , Nardi Marco V. , Wegner Berthold , Frisch Johannes , Hotchkiss Peter J. , Marder Seth R. , Barlow Stephen , Brédas Jean‐Luc , Koch Norbert
Published: December 2017

The uses of self‐assembled monolayers (SAMs) of dipolar molecules or of adsorbed molecular acceptors on electrode materials are common strategies to increase their work function, thereby facilitating hole injection into an organic semiconductor deposited on top. Here it is shown that a combination of both approaches can surpass the performance of the individual ones. By combined experimental and theoretical methods it is revealed that in a three‐component system, consisting of an indium‐tin‐oxide (ITO) electrode, a carbazole‐based phosphonic acid SAM, and a molecular acceptor layer on top of the SAM, charge transfer occurs from the ITO through the SAM to the acceptor layer, resulting in an electrostatic field drop over the charge‐neutral SAM. This result is in contrast to common expectations of either p‐doping the carbazole of the SAM or charge transfer complex formation between the carbazole and the acceptor molecules. A high work function of 5.7 eV is achieved with this combined system; even higher values may be accessible by exploiting the fundamental charge redistribution mechanisms identified here with other material combinations.
Emerging Role of the Band‐Structure Approach in Biohybrid Photovoltaics: A Path Beyond Bioelectrochemistry
Authors: Ravi Sai Kishore , Udayagiri Vishnu Saran , Suresh Lakshmi , Tan Swee Ching
Published: December 2017

Emulation of natural photosynthesis is central to modern photovoltaic research targeting sustainable and economic ways of solar energy harvesting. Natural photosynthetic systems have succeeded in efficiently harvesting solar energy which is key to the sustenance of life on earth. With numerous advances in understanding the structure and function of the natural photosystems, the last decade has witnessed new perspectives in developing bioinspired photovoltaics. Interestingly, organic photovoltaics (OPVs) adopting photosynthetic design principles and biophotovoltaics (BPVs) adopting solid‐state device architectures have now converged at a juncture. Several reports in recent years point to a new scope of improvement in OPVs and BPVs stemming from mutual inspiration. At this juncture, there are new perspectives by which a BPV can be designed that were previously limited only to conventional optoelectronics. Treating natural pigment–proteins as optically and electronically functional materials in any photovoltaic design, from the band‐theory viewpoint, is a promising direction for advancing BPVs beyond the boundaries of bioelectrochemistry. This article presents an overview of selected reports on BPVs in the last few years utilizing new design concepts based on band‐theory and its associated principles. In light of this, the scope of the band‐structure approach in BPVs is discussed, eliciting prospective research directions.
Micromotors Go In Vivo: From Test Tubes to Live Animals
Authors: Esteban‐Fernández de Ávila Berta , Angsantikul Pavimol , Li Jinxing , Gao Wei , Zhang Liangfang , Wang Joseph
Published: December 2017

While synthetic micromotors have been evaluated extensively under in vitro conditions for over a decade, their in vivo function has rarely been explored. Recent research effort has resulted in micromotors that display fast movement in complex biological media, and possess efficient cargo loading, transport, and release, along with good biocompatibility. These new capabilities have made synthetic micromotors promising active delivery tools for in vivo applications including treatment of enteral diseases. This review highlights several examples of recent in vivo applications using different types of biocompatible and biodegradable chemically powered body‐fuel‐propelled micromotors, including precise micromotor tissue localization and retention, autonomous gastric fluid neutralization and cargo release, and enhanced drug delivery toward enhanced treatment of stomach bacterial infection. Zn and Mg‐based micromotors, powered by body fluids, have shown unique advantages to operate at different regions of the gastrointestinal tract. This review also covers some early in vitro studies that paved the way for the current in vivo applications, along with future prospects and challenges.
Electrically Switchable, Hyper‐Reflective Blue Phase Liquid Crystals Films
Authors: Xu Xiaowan , Liu Zhen , Liu Yanjun , Zhang Xinhai , Zheng Zhigang , Luo Dan , Sun Xiaowei
Published: December 2017

Blue phase liquid crystals (BPLCs) with three‐dimensional periodicity have attracted significant attention due to their fast response time in the submillisecond region, which is critical in sequential liquid crystal displays and fast switchable photonic devices. However, the reflectivity of single‐layer BPLC films in the visible range, which is generally used for reflective display, is still low and limited to 50%, which hinders its use in a wide range of applications. Herein, hyper‐reflective, electrically switchable, fast responsive, and colorful reflective displays are demonstrated, which are based on multi‐layer BPLC films consisting of two single‐layer BPLC templates with opposite handedness. Hyper‐reflectivities of 89%, 82%, and 68% in the red, green, and blue color regions are achieved by refilling multi‐layer BPLC templates with achiral nematic liquid crystals. A reflectance switching of the film is achieved by unwinding the helical structure of the blue phase in an electric field, where the highest reflectance achieved in the red, green, and blue color regions is 94%, 86%, and 72%, respectively, in the presence of an electric field of 1 V µm−1. Compared to previously demonstrated BPLC films, this newly developed multi‐layer BPLC film substantially improves the overall reflection efficiency by up to 3.6 times. Our study on hyper‐reflective BPLC film provides an attractive platform for future development including sequential colorful reflective displays and switchable optoelectronic devices.
Imaging Inelastic Fracture Processes in Biomimetic Nanocomposites and Nacre by Laser Speckle for Better Toughness
Authors: Verho Tuukka , Karppinen Pasi , Gröschel André H. , Ikkala Olli
Published: December 2017

Mollusk nacre is a prototypical biological inorganic–organic composite that combines high toughness, stiffness, and strength by its brick‐and‐mortar microstructure, which has inspired several synthetic mimics. Its remarkable fracture toughness relies on inelastic deformations at the process zone at the crack tip that dissolve stress concentrations and stop cracks. The micrometer‐scale structure allows resolving the size and shape of the process zone to understand the fracture processes. However, for better scalability, nacre‐mimetic nanocomposites with aligned inorganic or graphene nanosheets are extensively pursued, to avoid the packing problems of mesoscale sheets like in nacre or slow in situ biomineralization. This calls for novel methods to explore the process zone of biomimetic nanocomposites. Here the fracture of nacre and nacre‐inspired clay/polymer nanocomposite is explored using laser speckle imaging that reveals the process zone even in absence of changes in optical scattering. To demonstrate the diagnostic value, compared to nacre, the nacre‐inspired nanocomposite develops a process zone more abruptly with macroscopic crack deflection shown by a flattened process zone. In situ scanning electron microscopy suggests similar toughening mechanisms in nanocomposite and nacre. These new insights guide the design of nacre‐inspired nanocomposites toward better mechanical properties to reach the level of synergy of their biological model.
Enabling Photon Upconversion and Precise Control of Donor–Acceptor Interaction through Interfacial Energy Transfer
Authors: Zhou Bo , Yan Long , Tao Lili , Song Nan , Wu Ming , Wang Ting , Zhang Qinyuan
Published: December 2017

Upconverting materials have achieved great progress in recent years, however, it remains challenging for the mechanistic research on new upconversion strategy of lanthanides. Here, a novel and efficient strategy to realize photon upconversion from more lanthanides and fine control of lanthanide donor–acceptor interactions through using the interfacial energy transfer (IET) is reported. Unlike conventional energy‐transfer upconversion and recently reported energy‐migration upconversion, the IET approach is capable of enabling upconversions from Er3+, Tm3+, Ho3+, Tb3+, Eu3+, Dy3+ to Sm3+ in NaYF4‐ and NaYbF4‐based core–shell nanostructures simultaneously. Applying the IET in a Nd–Yb coupled sensitizing system can also enable the 808/980 nm dual‐wavelength excited upconversion from a single particle. More importantly, the construction of IET concept allows for a fine control and manipulation of lanthanide donor–acceptor interactions and dynamics at the nanometer‐length scale by establishing a physical model upon an interlayer‐mediated nanostructure. These findings open a door for the fundamental understanding of the luminescence dynamics involving lanthanides at nanoscale, which would further help conceive new scientific concepts and control photon upconversion at a single lanthanide ion level.
Valence State Manipulation of Cerium Oxide Nanoparticles on a Titanium Surface for Modulating Cell Fate and Bone Formation
Authors: Li Jinhua , Wen Jin , Li Bin , Li Wan , Qiao Wei , Shen Jie , Jin Weihong , Jiang Xinquan , Yeung Kelvin W. K. , Chu Paul K.
Published: December 2017

Understanding cell–biomaterial interactions is critical for the control of cell fate for tissue engineering and regenerative medicine. Here, cerium oxide nanoparticles (CeONPs) are applied at different Ce4+/Ce3+ ratios (i.e., 0.46, 1.23, and 3.23) to titanium substrate surfaces by magnetron sputtering and vacuum annealing. Evaluation of the cytotoxicity of the modified surface to cultured rat bone marrow mesenchymal stem cells (BMSCs) reveals that the cytocompatibility and cell proliferation are proportional to the increases in Ce4+/Ce3+ ratio on titanium surface. The bone formation capability induced by these surface modified titanium alloys is evaluated by implanting various CeONP samples into the intramedullary cavity of rat femur for 8 weeks. New bone formation adjacent to the implant shows a close relationship to the surface Ce4+/Ce3+ ratio; higher Ce4+/Ce3+ ratio achieves better osseointegration. The mechanism of this in vivo outcome is explored by culturing rat BMSCs and RAW264.7 murine macrophages on CeONP samples for different durations. The improvement in osteogenic differentiation capability of BMSCs is directly proportional to the increased Ce4+/Ce3+ ratio on the titanium surface. Increases in the Ce4+/Ce3+ ratio also elevate the polarization of the M2 phenotype of RAW264.7 murine macrophages, particularly with respect to the healing‐associated M2 percentage and anti‐inflammatory cytokine secretion. The manipulation of valence states of CeONPs appears to provide an effective modulation of the osteogenic capability of stem cells and the M2 polarization of macrophages, resulting in favorable outcomes of new bone formation and osseointegration.
The Dawn of Lead‐Free Perovskite Solar Cell: Highly Stable Double Perovskite Cs2AgBiBr6 Film
Authors: Wu Cuncun , Zhang Qiaohui , Liu Yang , Luo Wei , Guo Xuan , Huang Ziru , Ting Hungkit , Sun Weihai , Zhong Xinrui , Wei Shiyuan , Wang Shufeng , Chen Zhijian , Xiao Lixin
Published: December 2017

Recently, lead‐free double perovskites have emerged as a promising environmentally friendly photovoltaic material for their intrinsic thermodynamic stability, appropriate bandgaps, small carrier effective masses, and low exciton binding energies. However, currently no solar cell based on these double perovskites has been reported, due to the challenge in film processing. Herein, a first lead‐free double perovskite planar heterojunction solar cell with a high quality Cs2AgBiBr6 film, fabricated by low‐pressure assisted solution processing under ambient conditions, is reported. The device presents a best power conversion efficiency of 1.44%. The preliminary efficiency and the high stability under ambient condition without encapsulation, together with the high film quality with simple processing, demonstrate promise for lead‐free perovskite solar cells.
Rational Design of Nickel Hydroxide‐Based Nanocrystals on Graphene for Ultrafast Energy Storage
Authors: Zhao Bote , Zhang Lei , Zhang Qiaobao , Chen Dongchang , Cheng Yong , Deng Xiang , Chen Yu , Murphy Ryan , Xiong Xunhui , Song Bo , Wong Ching‐Ping , Wang Ming‐Sheng , Liu Meilin
Published: December 2017

Compact, light, and powerful energy storage devices are urgently needed for many emerging applications; however, the development of advanced power sources relies heavily on advances in materials innovation. Here, the findings in rational design, one‐pot synthesis, and characterization of a series of Ni hydroxide‐based electrode materials in alkaline media for fast energy storage are reported. Under the guidance of density functional theory calculations and experimental investigations, a composite electrode composed of Co‐/Mn‐substituted Ni hydroxides grown on reduced graphene oxide (rGO) is designed and prepared, demonstrating capacities of 665 and 427 C g−1 at current densities of 2 and 20 A g−1, respectively. The superior performance is attributed mainly to the low deprotonation energy and the facile electron transport, as elaborated by theoretical calculations. When coupled with an electrode based on organic molecular‐modified rGO, the resulting hybrid device demonstrates an energy density of 74.7 W h kg−1 at a power density of 1.68 kW kg−1 while maintaining capacity retention of 91% after 10,000 cycles (20 A g−1). The findings not only provide a promising electrode material for high‐performance hybrid capacitors but also open a new avenue toward knowledge‐based design of efficient electrode materials for other energy storage applications.