bluuebunny/crossref_metadata_2025 huggingface dataset:
A trial reintroduction of the western quoll to a fenced conservation reserve: implications of returning native predators
Authors: West R. S. , Tilley L. , Moseby K. E.
Published: October 2019

While fenced reserves provide sanctuary for many threatened prey species, few projects have reintroduced native threatened predators, despite their potential role in regulating prey, addressing prey naivety, trophic regulation, and predator conservation. We aimed to investigate a set of issues unique to predator reintroduction into fenced reserves: how to contain predators that are naturally wide roaming, how to estimate carrying capacity, and will native predators impact resident threatened species? We conducted a trial reintroduction of four western quolls (Dasyurus geoffroii) (two males, two females) into a fenced reserve where four threatened prey species had been reintroduced and feral cats and foxes excluded. We monitored quoll survival, diet, movement and reproduction. Nocturnal foraging ranges measured over a fortnight were 3–17km2, favouring burrows in dune habitat for shelter. Dietary analysis indicated a preference for reintroduced bettongs and western barred bandicoots, and resident hopping mice. Successful breeding was recorded but the two male quolls eventually escaped the reserve by climbing over the external fence and did not return. Results suggest that quoll reintroductions to fenced reserves will require fence designs that enable quolls to climb back into the reserve, threat management outside the reserve, and close monitoring of prey species.
Microplastics in sediments and fish from the Red Sea coast at Jeddah (Saudi Arabia)
Authors: Al-Lihaibi Sultan , Al-Mehmadi Asmaa , Alarif Walied M. , Bawakid Nahed O. , Kallenborn Roland , Ali Aasim M.
Published: October 2019

Environmental contextMillions of tons of plastic debris are present in the marine environment. This study addresses the issue of microplastics in nearshore sediment and fish sampled from the Saudi coastal waters of the Red Sea. The results show that the sediments of all analysed stations contained microplastics, and microplastic particles were detected in almost half of the 140 sampled fish.
AbstractThe amounts of microplastics in sediment samples obtained from four stations along the Jeddah coast were shown to range from not detected to 119particleskg−1 wet sediment. Four classes of microplastic particles in the sediment, that is, fragments, granules, foams and fibres, were characterised by fluorescence microscopy. Microplastics of various forms and sizes were also identified in 44% of the 140 sampled fish (6 local species) in amounts ranging from not detected to 30 microplastic particles per individual. Polyethylene terephthalate and vinyl chloride-vinyl acetate copolymers were the dominant polymer types in the sediment samples identified by Fourier-transform infrared spectroscopy (FTIR) analysis, while polystyrene, polyethylene and polyester were the dominant polymer types detected in fish. FTIR analysis showed that the most detected fibres were made of polyester. The results of this study emphasise that microplastic pollution represents an emerging threat to the marine environment of the Red Sea. The results of this study provide useful background information for further investigations and provide an accurate overview of the microplastics distribution in the marine environment of the Saudi Red Sea.
Subcritical water extraction of indium from indium tin oxide scrap using organic acid solutions
Authors: Rahmawati Astrid , Kuncoro Kurniawan Adi , Ismadji Suryadi , Liu Jhy-Chern
Published: October 2019

Environmental contextIndium is a metal increasingly used in high-technology industries, creating a demand for efficient recycling technology. We investigated extraction of indium from waste using a subcritical water extraction with organic acids. Compared with conventional methods employing concentrated mineral acids, the new method is less corrosive, more efficient and required shorter extraction times.
AbstractSubcritical water extraction (SWE) was applied to extract indium (In) from indium tin oxide (ITO) scrap. Four organic acids, acetic acid, gluconic acid, citric acid (CA) and etidronic acid (EA), were used at a solid-to-liquid ratio (S/L) of 10gL−1. Neither acetic acid nor gluconic acid yielded significant extraction of indium. A total of 70.71% and 96.93% of indium was extracted using 1M of CA and EA respectively at 150°C and a final pressure of 18–19 bar within 30min. The extraction efficiency of In was shown to increase with the increase in acid concentration and in temperature. Compared with conventional extraction methods, SWE was more effective using less concentrated acids and required a shorter reaction time.
Measurements and APSIM modelling of soil C and N dynamics
Authors: Smith C. J. , Macdonald B. C. T. , Xing H. , Denmead O. T. , Wang E. , McLachlan G. , Tuomi S. , Turner D. , Chen D.
Published: October 2019

Process-based models capture our understanding of key processes that interact to determine productivity and environmental outcomes. Combining measurements and modelling together help assess the consequences of these interactions, identify knowledge gaps and improve understanding of these processes. Here, we present a dataset (collected in a two-month fallow period) and list potential issues related to use of the APSIM model in predicting fluxes of soil water, heat, nitrogen (N) and carbon (C). Within the APSIM framework, two soil water modules (SoilWat and SWIM3) were used to predict soil evaporation and soil moisture content. SWIM3 tended to overestimate soil evaporation immediately after rainfall events, and SoilWat provided better predictions of evaporation. Our results highlight the need for testing the modules using data that includes wetting and drying cycles. Two soil temperature modules were also evaluated. Predictions of soil temperature were better for SoilTemp than the default module. APSIM configured with different combinations of soil water and temperature modules predicted nitrate dynamics well, but poorly predicted ammonium-N dynamics. The predicted ammonium-N pool empties several weeks after fertilisation, which was not observed, indicating that the processes of mineralisation and nitrification in APSIM require improvements. The fluxes of soil respiration and nitrous oxide, measured by chamber and micrometeorological methods, were roughly captured by APSIM. Discrepancies between the fluxes measured with chamber and micrometeorological techniques highlight difficulties in obtaining accurate measurements for evaluating performance of APSIM to predict gaseous fluxes. There was uncertainty associated with soil depth, which contributed to surface emissions. Our results showed that APSIM performance in simulating N2O fluxes should be considered in relation to data precision and uncertainty, especially the soil depths included in simulations. Finally, there was a major disconnection between the predicted N loss from denitrification (N2 + N2O) and that measured using the 15N balance technique.
Social history and exposure to pathogen signals modulate social status effects on gene regulation in rhesus macaques
Authors: Sanz Joaquín , Maurizio Paul L. , Snyder-Mackler Noah , Simons Noah D. , Voyles Tawni , Kohn Jordan , Michopoulos Vasiliki , Wilson Mark , Tung Jenny , Barreiro Luis B.
Published: October 2019

Significance

Social adversity is strongly linked to health and fitness outcomes in humans and other social mammals. This observation arises in part through “biological embedding”: persistent, social environment-induced biological changes that may affect immune function. Here we show that low social status in female rhesus macaques leads to a highly proinflammatory response to both bacterial and viral challenge. In addition, we show that past social status also affects gene expression, and that past low status leads to reduced sensitivity to current social conditions. Thus, the first line of defense in the macaque immune system is altered by both current social conditions and a biological memory of past events. Our results provide insight into how social adversity gets under the skin over long time spans.
Differential development of large-cell neuroendocrine or small-cell lung carcinoma upon inactivation of 4 tumor suppressor genes
Authors: Lázaro Sara , Pérez-Crespo Miriam , Lorz Corina , Bernardini Alejandra , Oteo Marta , Enguita Ana Belén , Romero Eduardo , Hernández Pilar , Tomás Laura , Morcillo Miguel Ángel , Paramio Jesús M. , Santos Mirentxu
Published: October 2019

High-grade neuroendocrine lung malignancies (large-cell neuroendocrine cell carcinoma, LCNEC, and small-cell lung carcinoma, SCLC) are among the most deadly lung cancer conditions with no optimal clinical management. The biological relationships between SCLC and LCNEC are still largely unknown and a current matter of debate as growing molecular data reveal high heterogeneity with potential therapeutic consequences. Here we describe murine models of high-grade neuroendocrine lung carcinomas generated by the loss of 4 tumor suppressors. In an
Rbl1
-null background, deletion of
Rb1
,
Pten
, and
Trp53
floxed alleles after Ad-CMVcre infection in a wide variety of lung epithelial cells produces LCNEC. Meanwhile, inactivation of these genes using Ad-K5cre in basal cells leads to the development of SCLC, thus differentially influencing the lung cancer type developed. So far, a defined model of LCNEC has not been reported. Molecular and transcriptomic analyses of both models revealed strong similarities to their human counterparts. In addition, a
68
Ga-DOTATOC–based molecular-imaging method provides a tool for detection and monitoring the progression of the cancer. These data offer insight into the biology of SCLC and LCNEC, providing a useful framework for development of compounds and preclinical investigations in accurate immunocompetent models.
Evolution of sexual cooperation from sexual conflict
Authors: Servedio Maria R. , Powers John M. , Lande Russell , Price Trevor D.
Published: October 2019

In many species that form pair bonds, males display to their mate after pair formation. These displays elevate the female’s investment into the brood. This is a form of cooperation because without the display, female investment is reduced to levels that are suboptimal for both sexes. The presence of such displays is paradoxical as in their absence the male should be able to invest extra resources directly into offspring, to the benefit of both sexes. We consider that the origin of these displays lies in the exploitation of preexisting perceptual biases which increase female investment beyond that which is optimal for her, initially resulting in a sexual conflict. We use a combined population genetic and quantitative genetic model to show how this conflict becomes resolved into sexual cooperation. A cooperative outcome is most likely when perceptual biases are under selection pressures in other contexts (e.g., detection of predators, prey, or conspecifics), but this is not required. Cooperation between pair members can regularly evolve even when this provides no net advantage to the pair and when the display itself reduces a male’s contributions to raising the brood. The findings account for many interactions between the sexes that have been difficult to explain in the context of sexual selection.
Maternal prenatal stress phenotypes associate with fetal neurodevelopment and birth outcomes
Authors: Walsh Kate , McCormack Clare A. , Webster Rachel , Pinto Anita , Lee Seonjoo , Feng Tianshu , Krakovsky H. Sloan , O’Grady Sinclaire M. , Tycko Benjamin , Champagne Frances A. , Werner Elizabeth A. , Liu Grace , Monk Catherine
Published: October 2019

Significance

Despite decades of prenatal programming research showing that “the womb may be more important than the home” with respect to offspring health outcomes, no studies of which we are aware have considered multiple indicators of maternal stress to identify the types of maternal stress that most influence developing offspring. This study’s key contributions include the use of a data-driven procedure to specify types of maternal stress—psychological and subclinical physical health indicators—that predict offspring outcomes including sex at birth, risk of preterm birth, and fetal neurodevelopment. Social support is a key factor differentiating the stress groups and a malleable intervention target to improve offspring outcomes.
Fundamental helical geometry consolidates the plant photosynthetic membrane
Authors: Bussi Yuval , Shimoni Eyal , Weiner Allon , Kapon Ruti , Charuvi Dana , Nevo Reinat , Efrati Efi , Reich Ziv
Published: October 2019

Significance

The intricate structure of the membrane network that hosts the primary steps of photosynthesis in plant chloroplasts has intrigued scientists for decades. Here, we used electron tomography to determine this structure. We found that the network is consolidated by arrays of right- and left-handed helical structures. Similar arrangements of pitch-balanced helical elements of alternating handedness were proposed to be present in the endoplasmic reticulum and, remarkably, in ultradense nuclear matter. These arrays thus likely represent a universal means to connect between densely packed layers or sheets.
Alternative pathway androgen biosynthesis and human fetal female virilization
Authors: Reisch Nicole , Taylor Angela E. , Nogueira Edson F. , Asby Daniel J. , Dhir Vivek , Berry Andrew , Krone Nils , Auchus Richard J. , Shackleton Cedric H. L. , Hanley Neil A. , Arlt Wiebke
Published: October 2019

Significance

In the classic androgen biosynthesis pathway, testosterone is converted to 5α-dihydrotestosterone, a step crucially required for normal male genital virilization. Congenital adrenal hyperplasia (CAH) due to P450 oxidoreductase deficiency (PORD) is an inborn disorder that disrupts classic androgen biosynthesis. However, some affected girls present with severe genital virilization at birth. We hypothesized that this is explained by a prenatally active, alternative biosynthesis pathway to 5α-dihydrotestosterone. We show that adrenals and genital skin cooperate to produce androgens via the alternative pathway during the major period of human sexual differentiation and that neonates with PORD still produce alternative pathway androgens during the first weeks of life. This indicates that alternative pathway androgen biosynthesis drives prenatal virilization in CAH due to PORD.
KRAS G13D sensitivity to neurofibromin-mediated GTP hydrolysis
Authors: Rabara Dana , Tran Timothy H. , Dharmaiah Srisathiyanarayanan , Stephens Robert M. , McCormick Frank , Simanshu Dhirendra K. , Holderfield Matthew
Published: October 2019

KRASmutations occur in ∼35% of colorectal cancers and promote tumor growth by constitutively activating the mitogen-activated protein kinase (MAPK) pathway.KRASmutations at codons 12, 13, or 61 are thought to prevent GAP protein-stimulated GTP hydrolysis and renderKRAS-mutated colorectal cancers unresponsive to epidermal growth factor receptor (EGFR) inhibitors. We report here thatKRASG13-mutated cancer cells are frequently comutated withNF1GAP butNF1is rarely mutated in cancers withKRAScodon 12 or 61 mutations. Neurofibromin protein (encoded by theNF1gene) hydrolyzes GTP directly in complex with KRAS G13D, andKRASG13D-mutated cells can respond to EGFR inhibitors in a neurofibromin-dependent manner. Structures of the wild type and G13D mutant of KRAS in complex with neurofibromin (RasGAP domain) provide the structural basis for neurofibromin-mediated GTP hydrolysis. These results reveal that KRAS G13D is responsive to neurofibromin-stimulated hydrolysis and suggest that a subset ofKRASG13-mutated colorectal cancers that are neurofibromin-competent may respond to EGFR therapies.
Cellular defects resulting from disease-related myosin II mutations in
Drosophila
Authors: Kasza Karen E. , Supriyatno Sara , Zallen Jennifer A.
Published: October 2019

Significance

Cells require forces generated by the contractile actomyosin cytoskeleton to remodel and shape tissues. In humans, mutations in the myosin II motor are associated with a wide range of diseases, but the cellular mechanisms that underlie disease physiologies are not well understood. Using in vivo imaging and biophysical approaches, we show that engineering human disease mutations in fruit fly myosin II produces proteins with altered organization and dynamics that fail to drive rapid cell movements, resulting in abnormalities in embryo shape. Because many genes and cell behaviors are shared between fruit flies and humans, these results may reveal mechanisms underlying myosin II-related diseases in humans.
Redirection of SKN-1 abates the negative metabolic outcomes of a perceived pathogen infection
Authors: Nhan James D. , Turner Christian D. , Anderson Sarah M. , Yen Chia-An , Dalton Hans M. , Cheesman Hilary K. , Ruter Dana L. , Uma Naresh Nandhitha , Haynes Cole M. , Soukas Alexander A. , Pukkila-Worley Read , Curran Sean P.
Published: October 2019

Early host responses toward pathogens are essential for defense against infection. In
Caenorhabditis elegans
, the transcription factor, SKN-1, regulates cellular defenses during xenobiotic intoxication and bacterial infection. However, constitutive activation of SKN-1 results in pleiotropic outcomes, including a redistribution of somatic lipids to the germline, which impairs health and shortens lifespan. Here, we show that exposing
C. elegans
to
Pseudomonas aeruginosa
similarly drives the rapid depletion of somatic, but not germline, lipid stores. Modulating the epigenetic landscape refines SKN-1 activity away from innate immunity targets, which alleviates negative metabolic outcomes. Similarly, exposure to oxidative stress redirects SKN-1 activity away from pathogen response genes while restoring somatic lipid distribution. In addition, activating p38/MAPK signaling in the absence of pathogens, is sufficient to drive SKN-1–dependent loss of somatic fat. These data define a SKN-1– and p38-dependent axis for coordinating pathogen responses, lipid homeostasis, and survival and identify transcriptional redirection, rather than inactivation, as a mechanism for counteracting the pleiotropic consequences of aberrant transcriptional activity.
Multilayered horizontal operon transfers from bacteria reconstruct a thiamine salvage pathway in yeasts
Authors: Gonçalves Carla , Gonçalves Paula
Published: October 2019

Horizontal acquisition of bacterial genes is presently recognized as an important contribution to the adaptation and evolution of eukaryotic genomes. However, the mechanisms underlying expression and consequent selection and fixation of the prokaryotic genes in the new eukaryotic setting are largely unknown. Here we show that genes composing the pathway for the synthesis of the essential vitamin B1 (thiamine) were lost in an ancestor of a yeast lineage, the
Wickerhamiella/Starmerella
(W/S) clade, known to harbor an unusually large number of genes of alien origin. The thiamine pathway was subsequently reassembled, at least twice, by multiple HGT events from different bacterial donors involving both single genes and entire operons. In the W/S-clade species
Starmerella bombicola
we obtained direct genetic evidence that all bacterial genes of the thiamine pathway are functional. The reconstructed pathway is composed by yeast and bacterial genes operating coordinately to scavenge thiamine derivatives from the environment. The adaptation of the newly acquired operons to the eukaryotic setting involved a repertoire of mechanisms until now only sparsely documented, namely longer intergenic regions, post-horizontal gene transfer (HGT) gene fusions fostering coordinated expression, gene relocation, and possibly recombination generating mosaic genes. The results provide additional evidence that HGT occurred recurrently in this yeast lineage and was crucial for the reestablishment of lost functions and that similar mechanisms are used across a broad range of eukaryotic microbes to promote adaptation of prokaryotic genes to their new environment.
Rotation and propulsion in 3D active chiral droplets
Authors: Carenza Livio Nicola , Gonnella Giuseppe , Marenduzzo Davide , Negro Giuseppe
Published: October 2019

Significance

Chirality plays an important role in many biological systems. Biomolecules, such as DNA, actin, or microtubules, form helical structures, which at sufficiently high density and in the absence of active forces, tend to self-assemble into twisted cholesteric phases. We study the effect of activity on a droplet of chiral matter, finding a surprisingly rich range of dynamical behaviors ranging from spontaneous rotations to screw-like motion. The phenomena that we uncover require both thermodynamic chirality and activity and are linked to the nontrivial topology of the defects that form by necessity at the droplet surface. It would be of interest to look for analogues of the motility modes found here in chiral microorganisms occurring in nature or in synthetic active matter.
Cytosolic delivery of inhibitory antibodies with cationic lipids
Authors: Wang Hejia Henry , Tsourkas Andrew
Published: October 2019

Significance

Antibodies are important research tools because they can be developed to bind to as well as directly inhibit almost any protein. Unfortunately, antibodies cannot cross the plasma membrane and are therefore limited to perturbing membrane or secreted protein activity. We found that by appending anionic polypeptides (ApPs) to immunoglobulin G (IgG) antibodies, they could be complexed with cationic lipids, originally designed for nucleic acid delivery, through electrostatic interactions to enable efficient cytosolic antibody delivery. By fusing ApPs to photoreactive antibody-binding domains, we can rapidly functionalize almost any off-the-shelf IgG without genetic reengineering of the cargo IgG. Our cytosolically delivered antibodies are capable of inhibiting intracellular proteins, establishing a new approach for studying intracellular protein function with inhibitory antibodies.
Regulation of ETAA1-mediated ATR activation couples DNA replication fidelity and genome stability
Authors: Achuthankutty Divya , Thakur Roshan Singh , Haahr Peter , Hoffmann Saskia , Drainas Alexandros P. , Bizard Anna H. , Weischenfeldt Joachim , Hickson Ian D. , Mailand Niels
Published: October 2019

The ATR kinase is a master regulator of the cellular response to DNA replication stress. Activation of ATR relies on dual pathways involving the TopBP1 and ETAA1 proteins, both of which harbor ATR-activating domains (AADs). However, the exact contribution of the recently discovered ETAA1 pathway to ATR signaling in different contexts remains poorly understood. Here, using an unbiased CRISPR-Cas9–based genome-scale screen, we show that the ATR-stimulating function of ETAA1 becomes indispensable for cell fitness and chromosome stability when the fidelity of DNA replication is compromised. We demonstrate that the ATR-activating potential of ETAA1 is controlled by cell cycle– and replication stress–dependent phosphorylation of highly conserved residues within its AAD, and that the stimulatory impact of these modifications is required for the ability of ETAA1 to prevent mitotic chromosome abnormalities following replicative stress. Our findings suggest an important role of ETAA1 in protecting against genome instability arising from incompletely duplicated DNA via regulatory control of its ATR-stimulating potential.
Four-State Modulation in Middle of a Quantum Channel for Continuous-Variable Quantum Key Distribution Protocol with Noiseless Linear Amplifier*
Authors: Mao Yu , Liu Qi , Guo Ying , Zhang Hang , Zhou Jian
Published: October 2019

We characterize a modified continuous-variable quantum key distribution (CV-QKD) protocol with four states in the middle of a quantum channel. In this protocol, two noiseless linear amplifiers (NLAs) are inserted before each detector of the two parts, Alice and Bob, with the purpose of increasing the secret key rate and the maximum transmission distance. We present the performance analysis of the new four-state CV-QKD protocol over a Gaussian lossy and noisy channel. The simulation results show that the NLAs with a reasonable gain g can effectively enhance the secret key rate as well as the maximum transmission distance, which is generally satisfied in practice.
Optically Modulated Tunable O-Band Praseodymium-Doped Fluoride Fiber Laser Utilizing Multi-Walled Carbon Nanotube Saturable Absorber*
Authors: Ahmad H. , Ismail M. F. , Aidit S. N.
Published: October 2019

A tunable and optically modulated fiber laser utilizing a multi-walled carbon nanotube based saturable absorber is demonstrated for operation in the O-band region. A praseodymium-doped fluoride fiber is used as the gain medium and the system is capable of generating modulated outputs at 1300 nm. Pulsed output is observed at pump powers of 511 mW and above, with repetition rates and pulse widths that can be tuned from 41 kHz and 3.4 μs to 48 kHz and 2.4 μs, respectively, at the maximum pump power available. A maximum average output power of 100 μW with a corresponding single pulse energy of 2.1 nJ is measured, while the tunability of the proposed laser is from 1290 nm to 1308 nm. The output is stable, with peak power fluctuations of ∼4 dB from the average value.
Generation of Ultrahigh-Velocity Collisionless Electrostatic Shocks Using an Ultra-Intense Laser Pulse Interacting with Foil-Gas Target*
Authors: He Shu-Kai , Jiao Jin-Long , Deng Zhi-Gang , Lu Feng , Yang Lei , Zhang Fa-Qiang , Dong Ke-Gong , Hong Wei , Zhang Zhi-Meng , Zhang Bo , Teng Jian , Zhou Wei-Min , Gu Yu-Qiu
Published: October 2019

Ultra high-velocity collisionless shocks are generated using an ultra-intense laser interacting with foil-gas target, which consists of copper foil and helium gas. The energy of helium ions accelerated by shock and the proton probing image of the shock electrostatic field show that the shock velocity is 0.02c, where c is the light speed. The numerical and theory studies indicate that the collisionless shock velocity exceeding 0.1c can be generated by a laser pulse with picosecond duration and an intensity of 10
20
W/cm
2. This system may be relevant to the study of mildly relativistic velocity collisionless shocks in astrophysics.
High-Pressure Behavior of Nano-Pt in Hydrogen Environment*
Authors: Tian Can , Huang Xiao-li , Huang Yan-ping , Li Xin , Zhou Di , Wang Xin , Cui Tian
Published: October 2019

We choose nano-Pt in hydrogen environment to explore the size effect on the formation of metal hydrides. At 30 GPa, a phase transition in the metal lattice from the cubic to hexagonal phase is observed characterized by a drastically increased volume per metal atom, indicating the formation of PtH-P63
/mmc. We find that nano-Pt could form PtH at a lower pressure than the bulk Pt due to its high specific surface and structure defects. The present work provides the possible route to new metal hydrides under mild conditions.
Pressure-Induced Metallization Accompanied by Elongated S–S Dimer in Charge Transfer Insulator NiS2
*
Authors: Wu Hao , Zhou Yong-Hui , Yuan Yi-Fang , Chen Chun-Hua , Zhou Ying , Zhang Bo-Wen , Chen Xu-Liang , Gu Chuan-Chuan , An Chao , Wang Shu-Yang , Qi Meng-Yao , Zhang Ran-Ran , Zhang Li-Li , Li Xin-Jian , Yang Zhao-Rong
Published: October 2019

The insulator-metal transition triggered by pressure in charge transfer insulator NiS2 is investigated by combining high-pressure electrical transport, synchrotron x-ray diffraction and Raman spectroscopy measurements up to 40–50 GPa. Upon compression, we show that the metallization firstly appears in the low temperature region at ∼3.2 GPa and then extends to room temperature at ∼8.0 GPa. During the insulator-metal transition, the bond length of S–S dimer extracted from the synchrotron x-ray diffraction increases with pressure, which is supported by the observation of abnormal red-shift of the Raman modes between 3.2 and 7.1 GPa. Considering the decreasing bonding-antibonding splitting due to the expansion of S–S dimer, the charge gap between the S-ppπ* band and the upper Hubbard band of Ni-3d e
g
state is remarkably decreased. These results consistently indicate that the elongated S–S dimer plays a predominant role in the insulator-metal transition under high pressure, even though the p-d hybridization is enhanced simultaneously, in accordance with a scenario of charge-gap-controlled type.
Computational Simulation of Sodium Doublet Line Intensities in Multibubble Sonoluminescence*
Authors: Liang Jin-Fu , An Yu , Chen Wei-Zhong
Published: October 2019

We perform a computational simulation of the fluid dynamics of sodium doublet (Na-D) line emissions from one sonoluminescing bubble among the cavitation bubbles in argon-saturated Na hydroxide (NaOH) aqueous solutions. Our simulation includes the distributions of acoustic pressures and the dynamics of cavitation bubbles by numerically solving the cavitation dynamic equation and bubble-pulsation equation. The simulation results demonstrate that when the maximum temperature inside a luminescing bubble is relatively low, two emission peaks from excited Na are prominent within the emission spectra, at wavelengths of 589.0 and 589.6 nm. As the maximum temperature of the bubble increases, the two peaks merge into one peak and the full width at half maximum of this peak increases. These calculations match with the observations of Na-D line emissions from MBSL occurring in aqueous solutions of NaOH under an argon gas.
Maximum power and corresponding efficiency for two-level heat engines and refrigerators: optimality of fast cycles
Authors: Erdman P A , Cavina V , Fazio R , Taddei F , Giovannetti V
Published: October 2019

We study how to achieve the ultimate power in the simplest, yet non-trivial, model of a thermal machine, namely a two-level quantum system coupled to two thermal baths. Without making any prior assumption on the protocol, via optimal control we show that, regardless of the microscopic details and of the operating mode of the thermal machine, the maximum power is universally achieved by a fast Otto-cycle like structure in which the controls are rapidly switched between two extremal values. A closed formula for the maximum power is derived, and finite-speed effects are discussed. We also analyze the associated efficiency at maximum power showing that, contrary to universal results derived in the slow-driving regime, it can approach Carnot’s efficiency, no other universal bounds being allowed.
The role of oil palm biomass recycling on soil health in oil palm plantations
Authors: Tarigan R.S. , Suhardi  , Wahyuningsih R. , Pujianto  , Wahyuningsih P.A. , Marichal R. , Caliman J.P.
Published: October 2019

Oil palm cultivation produces a massive amount of biomass (e.g., empty fruit bunches (EFB), frond and trunk) which could be recycled directly in the plantation to maintain/improve the quality of soils. The impact of this biomass recycling, i.e., EFB and frond, - in term of chemical, physical and biological characteristics, will be analyzed. The fresh application of the EFB could alternate most of the soil parameters in line with the kinetics of the decomposition of the EFB and the release of nutrients. For example, the pH of the soil after the EFB application was higher during more than 18 months compared to the initial situation. Soil exchangeable potassium increased dramatically within a few days after EFB spreading. Frond recycling, at harvesting and pruning, modifies the chemical and physical characteristics of soils whether they were applied on heaps between palms in dedicated inter-rows, or spread on harvesting paths where they could reduce run-off and erosion. The systematic distribution of fronds in inter-rows reduced rainwater run-off by more than 30%, even on 5% gentle slopes. Subsequently, soil loss through erosion was reduced by 65% depending on the slope intensity of the terrain. Consequently, the loss of nutrients was considerably reduced, resulting in higher fertilizer efficiency. Similar measurements have been done when applying fresh EFB to the soil. The impact on soil physical fertility, i.e., rainwater infiltration rate and subsequently soil humidity are improved. We have also recorded a reduction of the soil resistance to penetration, as well as an improvement of the soil aggregate stability. Several representative parameters of soil biological activity, i.e., soil fauna feeding activity using bait-lamina test system and earthworm’ population showed the positive impact of EFB applications as well as frond spreading in inter-rows.
Fresh fruit bunch production of oil palm plantation in the lowland area of Sembilang Dangku Landscape
Authors: Segara Rio Octarizza , Hariyadi  , Sukarman  , Santoso Kresno Dwi
Published: October 2019

The results of the study showed that Sembilang Dangku Landscape had known two types of soil namely peat soil and mineral soil. Detail information for peat soil in this area namely Typic Haplosaprists and Typic Haplohemists meanwhile, for mineral soil, there are two types of soil that have been identified at these locations namely Inceptisols (Typic Endoaquepts and Typic Humaquepts) and Entisols (Typic Sulfaquents). This study aimed to analyze the production of oil palm plantations in lowland areas on marginal land. This research was conducted at six locations of oil palm plantations in Musi Banyuasin Regency, South Sumatra province. The methods used were descriptive quantitative and qualitative calculation of FFB (fresh fruit bunches) production that compared the standard potential production of the Palm Oil Research Center (PPKS referred in Indonesia). The yield of FFB oil palm productivity (ton/ha) on marginal land showed that Typic Haplosaprists, Typic Haplohemists and Typic Endoaquepts, Typic Humaquepts did not have a significant effect because yield from plantation management produced FFB production oil palm was quite good. The effect that has quite a different production is Entisols (Typic Sulfaquents) or L6 locations. Based on this research, the type of soil is a factor that greatly affects the productivity of oil palm.
Mix design of low-cement concrete with particle packing concept and superplasticizer application
Authors: Antoni A , Hardi E , Tandean R D , Hardjito D
Published: October 2019

The amount of cement paste used in concrete depends on aggregate particle packing, where the denser combination among particles with different particle sizes results in a minimum volume of voids (Vv). Theoretically, cement paste volume (Vp) is required to fill the void with the combination of fine and coarse aggregate, i.e., Vp/Vv = 100%. The purpose of this paper was to propose a concrete mix design method that could maximize the particle packing of aggregates to reduce the cement content in concrete mixture, hence producing low-cement concrete (LCC). The variables proposed were the ratio between the volume of paste to the volume of voids (Vp/Vv) as opposed to the cement content and the use of superplasticizer to control the workability of the fresh concrete. The results showed that by the combination of multi-sized coarse aggregates and fine aggregate, the smallest void volume of 23.5% could be achieved. The theoretically lowest cement content needed for a mixture with w/c 0.5 was 287 kg/m3. However, after trial mixing, the cement requirement was found to be almost equal with conventional concrete, i.e., about 310 kg/m3. Workability of the mixture depended on the paste volume to void volume ratio (Vp/Vv > 100%) and was greatly influenced by the superplasticizer content. The use of excessive superplasticizer could cause bleeding due to lack of fine particles in the low cement concrete mixture. The use of cementitious material, such as fly ash by 50%, to replace cement, significantly improves the workability and reduces the cement content below the minimum cement requirement with similar compressive strength as the water to cementitious ratio mainly controls compressive strength.
Using viscosity-modifying admixture to increase the cohesion of low-cement concrete mixture
Authors: Antoni A , Andreas A , Christian E , Hardjito D
Published: October 2019

Low-cement concrete (LCC) is made by considering the particle packing of the constituent material. The minimal content of cement paste is achieved by optimizing the coarse and fine aggregate particle size gradation to reduce the void volume (Vv) between the aggregate particles. Theoretically, the minimum cement paste can be calculated as the cementitious paste volume (Vp) filling the entire void volume (Vp/Vv = 100%). Practically, low fine or powder material content would reduce concrete mixture cohesion and cause bleeding and segregation. Viscosity-modifying admixture (VMA) can be added as an alternative to adding more cement powder or supplementary cementitious materials to improve the cohesion and stability of the LCC matrix. This study investigated the role of VMA addition in increasing stability in low water to cement ratio (w/c) mortar with an excessive dosage of superplasticizer and in high w/c mortar designed with low cement content. The results showed that adding VMA reduced bleeding and increased cohesion in the fresh mixture, and also increased the compressive strength of the hardened mortar. Although the addition of VMA cannot increase the workability of LCC, it had a beneficial effect when added to an LCC mixture as the 28-day compressive strength of the concrete with w/c of 0.5 was increased from 18.68 MPa to 22.93 MPa by adding 0.4% VMA by mass of cement.
Study of mechanical properties of fly ash-based geopolymer concrete
Authors: Hardjasaputra H , Cornelia M , Gunawan Y , Surjaputra I V , Lie H A , Rachmansyah  , Pranata Ng G
Published: October 2019

The world is facing the challenges of climate changes due to the increase in CO2 emissions. Cement production is one of the biggest contributors to CO2 emissions due to combustion processes that require high temperatures. The new development in building construction showed that fly ash based Geopolymer concrete can be as structure materials to reduce or even eliminate ordinary Portland cement concrete. This paper presented the research results of fly ash based geopolymer concrete mechanical properties, like the compressive strength, flexural strength, and Elastic Modulus. The data were collected from the test results of geopolymer concrete specimens made from 2 sources of Fly Ash with varying concentration of sodium hydroxide solution from 4 M up to 12 M. The range of achieved compressive strength was from normal to high strength concrete. The correlation between the compressive strength and flexural strength and the Elastic Modulus of geopolymer concrete will be the highlight of this paper. The mathematical formulation of compressive strength and its flexural strength and Elastic modulus will be determined and compared with normal Portland Cement Concrete.
Fiber-reinforced lightweight foamed concrete panels suitable for 3D printing applications
Authors: Falliano D , Sciarrone A , De Domenico D , Maugeri N , Longo P , Gugliandolo E , Ricciardi G
Published: October 2019

This contribution presents a set of experimental results on fiber-reinforced innovative lightweight panels (FRIL-panels) having thickness of 12mm. These panels are prepared with a peculiar foamed concrete that has a high viscosity and cohesion in the fresh state, which makes it particularly suitable for 3D printing applications. The FRIL-panels can be used for internal partitions, external infills, and suspended ceilings of buildings as more effective solutions than conventional plasterboard ones, with better thermal insulation and acoustic absorption properties due to the internal air-void microstructure. The aim of this work is to investigate the out-of-plane resistance of FRIL-panels, prepared with a density of 800kg/m3, under displacement-controlled three-point bending tests. In view of potential use in the precast industry, the FRIL-panels were placed into an accelerated concrete curing tank so as to speed up the overall production process. Modulus of rupture, ultimate deflection and collapse mode of FRIL-panels are critically analysed and discussed.
Self-healing of hardened cement paste affected by additional Ca2+ and CO3
2- ions with temperature control
Authors: Choi H , Inoue M
Published: October 2019

A self-healing phenomenon, in which the cracks become partially refilled as a result of rehydration of cement particles and deposition of CaCO3, has been observed in narrow cracks under a constant supply of moisture. Also, according to previous studies, the self-healing performance can be maximized by changing the temperature and pH to control the crystal form of CaCO3. In this study, attention was paid to the crystal form of CaCO3 generated in the self-healing process of a cement-based composite material and, in order to generate denser crystal of CaCO3, the change in the crystal form of CaCO3 generated in the hardened cement paste by changing the temperature condition was observed and analyzed. Also, to increase generation of CaCO3 which is a self-healing precipitate, nano-sized ultrafine CO32- bubbles using CO2 gas were used along with effective supply of Ca2+ through adjustment of aqueous solution. As a result, the possibility for effective generation and control of denser vaterite together with calcite was confirmed by adjusting the temperature to about 40°C under the condition of pH 12.
Exploring the knowledge of Prevention through Design (PtD) among Malaysian civil & structural designers
Authors: Che Ibrahim C K I , Belayutham S , Azmi E A , Hussain A
Published: October 2019

Devastating accidents in construction projects have elevated interests on providing early attention to safety hazards in design phase. Calls for changes in safety practice, through the Prevention through Design (PtD) concept has become increasingly vocal in various countries. In Malaysia, a Guidelines of Occupational Safety And Health in Construction Industry (Management) (OSHCI(M)), which stems from the PtD concept was launched to provide guidance for designers to enhance their PtD capability. This paper aims to explore the current PtD knowledge among C&S designers, in order to gauge the initial understanding towards OSHCI(M) implementation. Data were collected from 70 C&S designers in Malaysia through questionnaire survey and discussion conducted from four series of PtD workshops. The findings revealed that despite the current state of C&S designer’s knowledge still needs to be improved, majority of them have been very positive and supportive on the OSHCI(M) implementation. A number of recommendations towards improving the PtD knowledge have been highlighted; PtD early education; the use of pedagogical approach in PtD teaching; continuous training and establish integrated PtD educational resources. This study extends the PtD literature in construction context, in particular into the advancements towards improving the PtD knowledge among designers in the developing countries.
Reliability sensitivity analysis with subset simulation: application to a carbon dioxide storage problem
Authors: Xiao S , Oladyshkin S , Nowak W
Published: October 2019

Reliability sensitivity analysis (RSA) is a sensitivity analysis to measure the effect of modelling parameters on the predicted reliability of a system. It can be used for reliability-based design, safety management, etc. The output-classification-based version of RSA compares the failure-conditional probability density function (PDF) of model parameters with their unconditional PDF to measure sensitivity. The main challenge is to estimate failure-conditional PDFs. Usually, these PDFs can be estimated through the failure samples obtained by Monte Carlo simulation. However, practical systems usually have a small failure probability. For such cases, the brute-force Monte Carlo simulation requires a larger number of samples to obtain enough failure samples. Therefore, the computational cost is very high. In this paper, we propose to use subset simulation to estimate the output-classification-based reliability sensitivity index. Subset simulation introduces a series of intermediate failure events which are easier to sample from, and then iteratively samples in each constrained failure region until the target failure event is reached. Compared to brute-force Monte Carlo simulation, subset simulation samples in a direction towards the target failure domain. Therefore, the failure samples can be obtained more efficiently. We apply subset simulation to perform RSA for a carbon dioxide storage benchmark problem. We show that subset simulation can estimate the output-classification-based reliability sensitivity index more efficiently compared to brute-force Monte Carlo simulation.
Environmentally friendly foundation for the sustainability development of infrastructures in swamp area
Authors: Hakam A , Srihandayani S , Ismail F A , Asmirza M S , Hape M M
Published: October 2019

Infrastructure development in Indonesia, especially, has moved into swamp areas. Swamps are usually associated with saturated clay and peat soils that are soft and highly compressible. The low bearing capacity and the high excessive settlement are usually solved with piles and pre-consolidation. The remove and replace method with new and better material is sometimes also used. Those methods have really changed the characteristics of the soils and are not friendly to the environment. Some foundation constructions for soft soils have also been proposed, but, in their application, there are technical constraints which are difficult to overcome. Research on the light foundation in soft soils has been carried out to support the light load with a satisfactory settlement. Further studies are carried out to obtain a foundation construction that can support larger loads, but which are still friendly to the swamp environment. The bearing capacity and settlement of foundation is plotted in the graph to formulate the satisfaction indicators of the foundation. In addition, the simple formulation procedures for practical application requirements will be also provided since it is the target of this research for general applications. This foundation is very useful for the sustainability of infrastructure developments that is environmentally friendly.
Free vibration of orthotropic Levy-type solution plates by using SEM
Authors: Kiryu S , Alisjahbana S W , Alisjahbana I , Han A L , Gan B S
Published: October 2019

Orthotropic Levy-type solution plates considering shear deformation were solved by using the Spectral Element Method (SEM). In SEM, the exact solution of structural dynamic related problems can be solved by using the frequency-dependent shape functions. The solutions of SEM are accurate in decreasing the amount of Degree Of Freedoms (DOF) to discard the cost and computational disadvantages in the Finite Element Method (FEM). This study investigates the free vibration problems of orthotropic Levy-type solution plates solutions based on the two variable Refined Plate Theory (RPT). SEM for orthotropic Levy-type solution plates in the frequency domain was formulated to solve free vibration problems. The differential governing equations of the orthotropic plate element in SEM are formulated into the form of transcendental stiffness matrices. The boundary conditions of the spectral element model consist of four edge-type DOFs at each side of the orthotropic Levy-type solution plates. The natural frequencies of the plate are calculated by means of the Wittrick-Williams procedure. The numerical investigations are presented to show the accuracy, efficiency, and effectiveness of SEM without any discretization scheme.