bluuebunny/crossref_metadata_2025 huggingface dataset:
Perfluorocarbon Labeling of Human Glial-Restricted Progenitors for 19F Magnetic Resonance Imaging
Authors: Richard Jean-Philippe , Hussain Uzma , Gross Sarah , Taga Arens , Kouser Mehreen , Almad Akshata , Campanelli James T. , Bulte Jeff W.M. , Maragakis Nicholas J.
Published: January 2019

One of the fundamental limitations in assessing potential efficacy in Central Nervous System (CNS) transplantation of stem cells is the capacity for monitoring cell survival and migration noninvasively and longitudinally. Human glial-restricted progenitor (hGRP) cells (Q-Cells) have been investigated for their utility in providing neuroprotection following transplantation into models of amyotrophic lateral sclerosis (ALS) and have been granted a Food and Drug Administration (FDA) Investigational New Drug (IND) for intraspinal transplantation in ALS patients. Furthermore, clinical development of these cells for therapeutic use will rely on the ability to track the cells using noninvasive imaging methodologies as well as the verification that the transplanted GRPs have disease-relevant activity. As a first step in development, we investigated the use of a perfluorocarbon (PFC) dual-modal (19F magnetic resonance imaging [MRI] and fluorescence) tracer agent to label Q-Cells in culture and following spinal cord transplantation. PFCs have a number of potential benefits that make them appealing for clinical use. They are quantitative, noninvasive, biologically inert, and highly specific. In this study, we developed optimized PFC labeling protocols for Q-Cells and demonstrate that PFCs do not significantly alter the glial identity of Q-Cells. We also show that PFCs do not interfere with the capacity for differentiation into astrocytes either in vitro or following transplantation into the ventral horn of the mouse spinal cord, and can be visualized in vivo by hot spot 19F MRI. These studies provide a foundation for further preclinical development of PFCs within the context of evaluating Q-Cell transplantation in the brain and spinal cord of future ALS patients using 19F MRI. Stem Cells Translational Medicine  2019;8:355–365
Assessing health care interventions via an interrupted time series model: Study power and design considerations
Authors: Cruz Maricela , Gillen Daniel L. , Bender Miriam , Ombao Hernando
Published: January 2019

The delivery and assessment of quality health care is complex with many interacting and interdependent components. In terms of research design and statistical analysis, this complexity and interdependency makes it difficult to assess the true impact of interventions designed to improve patient health care outcomes. Interrupted time series (ITS) is a quasi‐experimental design developed for inferring the effectiveness of a health policy intervention while accounting for temporal dependence within a single system or unit. Current standardized ITS methods do not simultaneously analyze data for several units nor are there methods to test for the existence of a change point and to assess statistical power for study planning purposes in this context. To address this limitation, we propose the “Robust Multiple ITS” (R‐MITS) model, appropriate for multiunit ITS data, that allows for inference regarding the estimation of a global change point across units in the presence of a potentially lagged (or anticipatory) treatment effect. Under the R‐MITS model, one can formally test for the existence of a change point and estimate the time delay between the formal intervention implementation and the over‐all‐unit intervention effect. We conducted empirical simulation studies to assess the type one error rate of the testing procedure, power for detecting specified change‐point alternatives, and accuracy of the proposed estimating methodology. R‐MITS is illustrated by analyzing patient satisfaction data from a hospital that implemented and evaluated a new care delivery model in multiple units.
Synthesis of Inorganic–Organic 2D CdSe Slab‐Diamine Quantum Nets
Authors: Choo Seungjun , Ban Hyeong Woo , Gu Da Hwi , Jeong Hyewon , Jo Seungki , Baek Seongheon , Jo Wook , Son Jae Sung
Published: January 2019

Porous semiconductors attract great interest due to their unique structural characteristics of high surface area as well as their intrinsic optical and electronic properties. In this study, synthesis of inorganic–organic 2D CdSe slabs‐diaminooctane (DAO) porous quantum net structures is demonstrated. It is found that the hybrid 2D CdSe‐DAO lamellar structures are disintegrated into porous net structures, maintaining an ultrathin thickness of ≈1 nm in CdSe slabs. Furthermore, the CdSe slabs in quantum nets show the highly shifted excitonic transition in the absorption spectrum, demonstrating their strongly confined electronic structures. The possible formation mechanism of this porous structure is investigated with the control experiments of the synthesis using n‐alkyldiamines with various hydrocarbon chain lengths and ligand exchange of DAO with oleylamine. It is suggested that a strong van der Waals interaction among long chain DAO may exert strong tensile stress on the CdSe slabs, eventually disintegrating slabs. The thermal decomposition of CdSe‐DAO quantum nets is further studied to form well‐defined CdSe nanorods. It is believed that the current CdSe‐DAO quantum nets will offer a new type of porous semiconductors nanostructures under a strong quantum‐confinement regime, which can be applied to various technological areas of catalysts, electronics, and optoelectronics.
A measurement framework for software product maturity assessment
Authors: Abdellatif Ahmad , Alshayeb Mohammad , Zahran Sami , Niazi Mahmood
Published: January 2019

The need to ensure the quality of software is growing in importance on a daily basis due to the growing role of software in critical products and application areas, such as defense, aerospace, aviation, and medicine. To meet this need, many organizations use the Capability Maturity Model Integration process model to assess and improve software development processes. This paper proposes a framework for measuring software product maturity as an indicator of product quality. The proposed framework consists of two parts: a reference model and an assessment method. The reference model provides a platform for gathering product quality indicators as evidence of product capability, which reflects the product's maturity. The quality indicators are then used to assess the product maturity level. The assessment method utilizes standard steps for assessing product maturity that are reflected in the degree of the product's conformance with the relevant quality attributes defined and agreed upon by the product's stakeholders. The proposed framework enables measuring the quality of the product from the developers' and the users' perspective. The proposed maturity model and the assessment method can help software organizations and software clients ensure that software products meet the appropriate quality levels.
Genistein induces apoptosis in vitro and has antitumor activity against human leukemia HL‐60 cancer cell xenograft growth in vivo
Authors: Hsiao Yin‐Chen , Peng Shu‐Fen , Lai Kuang‐Chi , Liao Ching‐Lung , Huang Yi‐Ping , Lin Chin‐Chung , Lin Meng‐Liang , Liu Kuo‐Ching , Tsai Chin‐Chuan , Ma Yi‐Shih , Chung Jing‐Gung
Published: January 2019

Genistein, a major isoflavone compound in soybeans, has been shown to have biological activities including anti‐cancer activates. In the present, we investigated the anti‐leukemia activity of genistein on HL‐60 cells in vitro. The percentage of viable cell, cell cycle distribution, apoptotic cell death, reactive oxygen species (ROS), and Ca2+ production and the level of ΔΨm were measured by flow cytometric assay. Cell apoptosis and endoplasmic reticulum (ER) stress associated protein expressions were examined by Western blotting assay. Calpain 1, GRP78, and GADD153 expression were measured by confocal laser microscopy. Results indicated that genistein‐induced cell morphological changes, decreased the total viable cells, induced G2/M phase arrest and DNA damage and fragmentation (cell apoptosis) in HL‐60 cells. Genistein promoted ROS and Ca2+ productions and decreased the level of ΔΨm in HL‐60 cells. Western blotting assay demonstrated that genistein increased ER stress‐associated protein expression such as IRE‐1α, Calpain 1, GRP78, GADD153, caspase‐7, caspase‐4, and ATF‐6α at 20‐50 μM treatment and increased apoptosis associated protein expression such as pro‐apoptotic protein Bax, PARP‐cleavage, caspase‐9, and ‐3, but decreased anti‐apoptotic protein such as Bcl‐2 and Bid in HL‐60 cells. Calpain 1, GRP78, and GADD153 were increased in HL‐60 cells after exposure to 40 μM of genistein. In animal xenografted model, mice were intraperitoneally injected with genistein (0, 0.2, and 0.4 mg/kg) for 28 days and the body weight and tumor volume were recorded. Results showed that genistein did not affect the body weights but significantly reduced the tumor weight in 0.4 mg/kg genistein‐treated group. Genistein also increased the expressions of ATF‐6α, GRP78, Bax, Bad, and Bak in tumor. In conclusion, genistein decreased cell number through G2/M phase arrest and the induction of cell apoptosis through ER stress‐ and mitochondria‐dependent pathways in HL‐60 cells and suppressed tumor properties in vivo.
Coronarin D induces human oral cancer cell apoptosis though upregulate JNK1/2 signaling pathway
Authors: Liu Yen‐Tze , Hsieh Ming‐Ju , Lin Jen‐Tsun , Chen Gene , Lin Chia‐Chieh , Lo Yu‐Sheng , Chuang Yi‐Ching , Hsi Yi‐Ting , Chen Mu‐Kuan , Chou Ming‐Chih
Published: January 2019

The incidence of oral cancer is increasing all over the world, with rates particularly high in Southeast Asian countries, such as Taiwan. Coronarin D (CD) has been confirmed to have anti‐inflammatory, anti‐bacterial effects, and anti‐apoptotic effects in human hepatocellular carcinoma and nasopharyngeal carcinoma. The purpose of this study is to explore whether CD has a suppression effect on oral cancer cells and the mechanisms involved. The results of our study revealed the significantly decreased cancer cell viability and increased activation of apoptosis via increased loss of mitochondrial membrane potential, increased death receptors, leading to the activation of caspase‐8, ‐9, ‐3. Moreover, the rate of apoptosis of cells treated with CD plus JNK inhibitors was decreased compared to CD‐treated cells. This is the first study to demonstrate that CD induces apoptosis in human oral cancer cells and can be expected to be a promising anticancer agent for oral cancer treatment.
Uptake of Pb(II) onto nanochitosan/sodium alginate hybrid beads: Mechanism and kinetics study
Authors: Ablouh El‐houssaine , Essaghraoui Abderrazzaq , Eladlani Nadia , Rhazi Mohammed , Taourirte Moha
Published: January 2019

Nanochitosan/sodium alginate (NCS/SA) beads were prepared using nanochitosan and alginate as a high‐performance absorbent for Pb(II) removal from aqueous solution. The morphology, structure, thermal stability, surface area, and elements present in the NCS/SA beads before and after adsorption were characterized using instrumental techniques like SEM, FTIR, TGA, BET, and EDX analysis, respectively. Various adsorption parameters were studied. The results indicated that the equilibrium adsorption data were fitted to Langmuir isotherms and the maximum Langmuir monolayer capacity of Pb(II) was 178.57 mg/g at 45°C. The adsorption process was in good agreement with pseudo‐first‐order kinetic model. Mechanism studies showed that electrostatic interaction and ion exchange were the major mechanisms for lead (II) removal by the NCS/SA beads. The results of this study indicate that NCS/SA beads could be used as an effective adsorbent for the elimination of lead (II) present in aqueous solution.

Practitioner points

Nanochitosan/sodium alginate beads were synthesized using Ca2+ as a crosslinking agent.

NCS/SA beads were used to remove Pb(II) for the first time and working parameters were optimized.

Adsorption monolayer capacity of NCS/SA adsorbent towards Pb (II) was found to be 178.57 mg/g.
χ-systems for correlation functions
Authors: Caetano J. , Toledo J.
Published: January 2019

Abstract

We consider the strong coupling limit of 4-point functions of heavy operators in

$$ \mathcal{N} $$

N

= 4 SYM dual to strings with no spin in AdS. We restrict our discussion for operators inserted on a line. The string computation factorizes into a state-dependent sphere part and a universal AdS contribution which depends only on the dimensions of the operators and the cross ratios. We use the integrability of the AdS string equations to compute the AdS part for operators of arbitrary conformal dimensions. The solution takes the form of TBA-like integral equations with the minimal AdS string-action computed by a corresponding free-energy-like functional. These TBA-like equations stem from a peculiar system of functional equations which we call a χ-system. In principle one could use the same method to solve for the AdS contribution in the N-point function. The discrete data that parameterizes these solutions enters through the analog of the chemical-potentials in the TBA-like equations. Finally, for operators dual to strings spinning in the same equator in S
5 (i.e. BPS operators of the same type) the sphere part is simple to compute. In this case (which is generically neither extremal nor protected) our result allows the construction of the complete, strong coupling 4-point function.
Authoritarianism, trauma, and insecure bonds during the Greek economic crisis
Authors: Sochos Antigonos
Published: January 2019

This correlational study investigated the link between authoritarian attitudes, psychosocial trauma, and attachment insecurity in the context of a significant community and personal threat – the recent economic crisis in Greece. The study utilised a large community sample and five self-report measures - Right-Wing Authoritarianism Scale-S, Social Group Attachment Scale, Relationship Questionnaire, Perceived Cohesion Scale, and Impact of Events Scale-R. It was hypothesised that authoritarianism would be independently linked with insecurity in two types of bond (person-to-person and person-to-state) via the experience of post-traumatic stress and perceptions of social cohesion. Structural Equation Modelling indices suggested that the model had a very good fit.
Asian Corporate Governance
Authors: Yoshikawa Toru
Published: January 2019

This Element aims to achieve three objectives. First, it explores some key institutional characteristics of several Asian economies that are relevant to corporate governance practices. Second, it reviews corporate governance codes or rules in those economies and examines levels of requirements in terms of formal rules. Third, this Element looks at recent trends related to corporate governance such as executive compensation and a proportion of independent directors on boards of large listed firms.
Democratic or cultural peace? Examining the joint democratic peace proposition through the lens of shared emancipative values
Authors: Omelicheva Mariya , Carter Brittnee
Published: January 2019

Is it joint democracy or state similarity that has a pacifying impact on interstate relations? This study explores the complementarity of the two propositions and demonstrates the potential of a particular kind of shared emancipative culture embracing values of autonomy, equality, choice, and voice to amplify the impact of joint democracy on interstate conflict. The data on cultural values, which comes from the World Values Survey, was integrated with the data from the Correlates of War Project to test the impact of joint democracy and cultural similarity on militarised interstate disputes (1981–2010). We find that culturally similar dyads are less likely to be involved in conflict with each other than culturally dissimilar dyads. Although, cultural similarity does not wash out the pacifying effect of democracy, it offers a complementary explanation to the democratic peace. We also find that states that are democratic and share higher than average scores on the emancipative values are less likely to engage in militarised interstate disputes than democratic states, which are culturally dissimilar or score low on the emancipative dimensions. This provides support for an additional normative/cultural impact on democratic peace.
Effects of offering grass silage alone or in combination with lupin/triticale, lupin/wheat or pea/oat whole-crop silages on animal performance, meat quality and fatty acid composition of beef from cattle offered two levels of concentrate
Authors: Kennedy P. C. , Dawson L. E. R. , Lively F. O. , Steen R. W. J. , Fearon A. M. , Moss B. W. , Kilpatrick D. J.
Published: January 2019

An experiment was carried out to examine the effects of offering beef cattle five silage diets. These were perennial ryegrass silage (PRGS) as the sole forage, tall fescue/perennial ryegrass silage (FGS) as the sole forage, PRGS in a 50:50 ratio on a dry matter (DM) basis with lupin/triticale silage (LTS), lupin/wheat silage (LWS) and pea/oat silage (POS). Each of the five silage diets was supplemented with 4 and 7 kg of concentrates/head/day in a five silages × two concentrate intakes factorial design. A total of 90 cattle were used in the 121-day experiment. The grass silages were of medium digestibility and were well preserved. The legume/cereal silages had high ammonia N, high acetic acid, low lactic acid, low butyric acid and low digestible organic matter concentrations (542, 562 and 502 g/kg DM for LTS, LWS and POS, respectively). Silage treatment did not significantly affect liveweight gain, carcass gain, carcass characteristics, the instrumental assessment of meat quality or fatty acid composition of theM. longissimus dorsimuscle. In view of the low yields of the legume/cereal crops, it is concluded that the inclusion of spring-sown legume/cereal silages in the diets of beef cattle is unlikely to be advantageous.
Long-term care preference among Japanese older adults: differences by age, period and cohort
Authors: Sugisawa Hidehiro , Sugihara Yoko , Nakatani Yomei
Published: January 2019

This study examined the differences in the preference for long-term care (LTC) by age, period and cohort (A-P-C) in Japanese older adults through repeated cross-sectional surveys from 1998 – before the establishment of LTC insurance – to 2016, in a suburban city of metropolitan Tokyo. We analysed the direct effects of A-P-C on the preference for LTC, as well as the interaction effects of A-P-C on preference by gender, family structure and activities of daily living. Data were obtained at six time-points using repeated cross-sectional surveys for people aged 65 and older; surveys were conducted in 1998, 2002, 2004, 2010, 2013 and 2016. The preference for LTC was composed of three categories: informal care, community LTC services (CLTCS) and institutional LTC services (ILTCS). The cross-classified random-effect model was used to specify A-P-C effects. Informal care, CLITCS, ILTCS and other/no answer composed 35, 23, 33 and 9 per cent of preferences, respectively. In terms of the period effect, while there was an increase in levels of preference for CLTC between 1998 and 2010 as compared to informal care, the levels of preference were almost identical after 2010. In terms of the age effect, younger participants were more likely to prefer CLTCS and ILTCS over informal care. Moreover, the age influence was stronger in females and respondents who lived alone. We did not observe a cohort effect for preference. This study suggests that there are gaps by period and age between the preference for LTC services and the actual LTC use in Japanese older adults, and as a result, the use of actual LTC services cannot fully reflect the intentions and preference for LTC in them.
Perceptions of home in long-term care settings: before and after institutional relocation
Authors: Wada Mineko , Canham Sarah L. , Battersby Lupin , Sixsmith Judith , Woolrych Ryan , Fang Mei Lan , Sixsmith Andrew
Published: January 2019

Although moving from institutional to home-like long-term care (LTC) settings can promote and sustain the health and wellbeing of older adults, there has been little research examining how home is perceived by older adults when moving between care settings. A qualitative study was conducted over a two-year period during the relocation of residents and staff from an institutional LTC home to a purpose-built LTC home in Western Canada. The study explored perceptions of home amongst residents, family members and staff. Accordingly, 210 semi-structured interviews were conducted at five time-points with 35 residents, 23 family members and 81 staff. Thematic analyses generated four superordinate themes that are suggestive of how to create and enhance a sense of home in LTC settings: (a) physical environment features; (b) privacy and personalisation; (c) autonomy, choice and flexibility; and (d) connectedness and togetherness. The findings reveal that the physical environment features are foundational for the emergence of social and personal meanings associated with a sense of home, and highlight the impact of care practices on the sense of home when the workplace becomes a home. In addition, tension that arises between providing care and creating a home-like environment in LTC settings is discussed.
Mapping out particle placement in Englishes around the world: A study in comparative sociolinguistic analysis
Authors: Grafmiller Jason , Szmrecsanyi Benedikt
Published: January 2019

This study explores variability in particle placement across nine varieties of English around the globe, utilizing data from the International Corpus of English and the Global Corpus of Web-based English. We introduce a quantitative approach for comparative sociolinguistics that integrates linguistic distance metrics and predictive modeling, and use these methods to examine the development of regional patterns in grammatical constraints on particle placement in World Englishes. We find a high degree of uniformity among the conditioning factors influencing particle placement in native varieties (e.g., British, Canadian, and New Zealand English), while English as a second language varieties (e.g., Indian and Singaporean English) exhibit a high degree of dissimilarity with the native varieties and with each other. We attribute the greater heterogeneity among second language varieties to the interaction between general L2 acquisition processes and the varying sociolinguistic contexts of the individual regions. We argue that the similarities in constraint effects represent compelling evidence for the existence of a shared variable grammar and variation among grammatical systems is more appropriately analyzed and interpreted as a continuum rather than multiple distinct grammars.
Listing postmodernism
Authors: Franklin Geraint
Published: January 2019

Like modernism, postmodernism was an international phenomenon with significant regional variants. Britain played an important role in mediating between the very different postmodernisms developing in North America and Continental Europe. It helped that London was at the centre of architectural discourse in the 1970s. The Architectural Association attracted international figures such as Charles Jencks, Léon Krier, and Rem Koolhaas, while publications such as Architectural Design and Andreas Papadakis's Academy Editions imprint combined coverage of new buildings with excursions into theory and history. James Stirling, John Outram, and Edward Jones won important overseas commissions, while the work of Terry Farrell, Jeremy Dixon, and others was exhibited at the seminal 1980 Venice Biennale.
Air design, meteorological architecture, and atmospheric preservation: towards a theory of feeling
Authors: Corbo Stefano
Published: January 2019

In 1960, Belgian artist Rene Magritte painted La Corde Sensible. In the background is a natural landscape, characterised by mountains and by a river. At the front is a champagne glass topped by a cloud. It prompts questions: does the cloud have its own weight? Is the glass mediating between the liquid state of the river and the gaseous state of the cloud? A few years later in 1972, the Viennese group Haus-Rucker-Co depicted a similar provocative scenario in ‘Big Piano’. In place of a champagne glass, a ladder with many steps – each with a different sound – reaches towards a cloud, which is a site of immersion and the loss of orientation.

These two examples, along with other artistic manifestations from the same period, reveal the rise of an aesthetic sensibility, which for the first time, questioned traditional physical and perceptual boundaries seemingly fixed by tradition, pursuing a sort of material evanescence. They illustrate a process of formal and conceptual dematerialisation. Generally, one may say that, from the second half of the twentieth century, the discipline of aesthetics experienced a radical change: shifting away from semantic or hermeneutic interpretations back to its original meaning: aesthetics as aisthesis, the ancient Greek word for perception. This implied a rediscovery of the body, the rehabilitation of the senses, and a renewed interest in phenomenology.
An Improved Method to Shorten Physiological Dormancy of Giant Ragweed (Ambrosia trifida) Seed
Authors: Harre Nick T. , Weller Stephen C. , Young Bryan G.
Published: January 2019

Timely results from whole-plant, herbicide-resistant weed screenings are crucial to heighten grower awareness. However, the high degree of physiological dormancy of giant ragweed (Ambrosia trifidaL.) seed exacerbates this process. The most effective methods for alleviating dormancy, to date, are either labor-intensive (embryo excision) or require several weeks (soil stratification). This research describes a conditioning process involving clipping and aeration of seed in water that is highly effective at alleviating dormancy and requires less skill and time compared with previous techniques.Ambrosia trifidaseeds were collected over 2 yr at two different collection timings (September 25, “early”; October 25, “late”), subjected to various treatments intended to release dormancy, and evaluated for emergence over 18 d in the greenhouse. The use of germination-promoting chemicals (ethephon, gibberellic acid, and thiourea) generally provided no increase in emergence compared with water and occasionally produced seedlings with abnormal growth unsuitable for further experimentation. Conditioning yielded between 30% and 33% emergence for both early and late collections of seeds with no afterripening period compared with 0% emergence for seeds imbibed in water. Following an 8-wk period of dry storage at 4 C, conditioning yielded nearly 80% emergence for both collection timings, while emergence of seeds imbibed in water was 10% and 27% for early and late collections, respectively. Soil stratification in moist soil for 8 wk at 4 C was the second most effective treatment, yielding 46% to 49% emergence across both collections. Parameters of the Weibull function further indicated the conditioning treatment had the fastest rate of emergence and shortest lag phase between planting and first emergence. Methods to germinateA. trifidawithout an afterripening period have previously been unsuccessful. Therefore, the seed-conditioning method outlined in this work will be useful in expediting the confirmation of herbicide-resistantA. trifidaincidences.
Is It Possible to Improve Test Takers’ Perceptions of Ability	Tests by Providing an Explanation?
Authors: Melchers Klaus G. , Körner Barbara
Published: January 2019

Abstract. Previous meta-analytic findings have revealed that explanations can improve applicants’ perceptions of selection procedures. However, they also suggest that these positive effects do not generalize to ability tests. Given some limitations of previous studies and the small empirical basis for the corresponding meta-analytic results, we had another look at whether perceptions of ability tests can be improved by providing an explanation. In two experimental studies, participants had to complete either an attention or a general mental ability test. In the explanation group, a justification was given concerning the content, relevance, and predictiveness of the test. In contrast, no explanation was given in the control group. Providing an explanation significantly improved test takers’ fairness perceptions.
Not All Leaving Is Created Equal
Authors: Li Huisi (Jessica) , Yu Kun , Huang Youhuang , Jin Xiaotong
Published: January 2019

Abstract. Drawing on social cognitive career theory (SCCT) and the focus–congruence approach, this study examines how organizational and occupational turnover is differently influenced by work-related factors. Using a sample of 2,353 teachers in rural China, results first showed that negative relationships between organization-focused predictors (i.e., leader support, colleague support, and physical resources for work) and organizational turnover intentions were significant. Similarly, the negative relationship between occupation-focused predictors (i.e., occupational satisfaction, salary satisfaction, and occupational choice motivations) and occupational turnover intentions was also significant. Moreover, occupation-focused predictors have a stronger relationship with occupational turnover intentions than organizational turnover intentions, and vice versa. Implications for research and practice are discussed.
Induced Polarization of Rocks Containing Metallic Particles: Evidence of Passivation Effect
Authors: Gurin Grigory , Titov Konstantin , Ilyin Yuri
Published: January 2019

We studied the impact of electrical isolation (passivation) of metallic particles on induced polarization (IP) parameters. We carried out laboratory experiments with six synthetic models made of sieved sand mixed with metallic particles. The purpose of this experiment was to understand what mechanism (polarization of positive and negative charge carriers within the particles or interfacial polarization) was responsible for the IP effect. Size and location of passivated zones on the particle surfaces varied from model to model. We observed a decrease of the total chargeability and relaxation time values with the increase of passivated surface. Fully passivated metallic particles showed no IP effect. These data suggest the dominant role of the interface phenomena in IP associated with metallic particles.
Millennial‐Scale Vulnerability of the Antarctic Ice Sheet to Regional Ice Shelf Collapse
Authors: Martin Daniel F. , Cornford Stephen L. , Payne Antony J.
Published: January 2019

The Antarctic Ice Sheet (AIS) remains the largest uncertainty in projections of future sea level rise. A likely climate‐driven vulnerability of the AIS is thinning of floating ice shelves resulting from surface‐melt‐driven hydrofracture or incursion of relatively warm water into subshelf ocean cavities. The resulting melting, weakening, and potential ice shelf collapse reduces shelf buttressing effects. Upstream ice flow accelerates, causing thinning, grounding‐line retreat, and potential ice sheet collapse. While high‐resolution projections have been performed for localized Antarctic regions, full‐continent simulations have typically been limited to low‐resolution models. Here we quantify the vulnerability of the entire present‐day AIS to regional ice shelf collapse on millennial timescales treating relevant ice flow dynamics at the necessary ∼1‐km resolution. Collapse of any of the ice shelves dynamically connected to the West Antarctic Ice Sheet (WAIS) is sufficient to trigger ice sheet collapse in marine‐grounded portions of the WAIS. Vulnerability elsewhere appears limited to localized responses.
Robust Estimation of Rupture Properties at Propagating Front of Laboratory Earthquakes
Authors: Xu Shiqing , Fukuyama Eiichi , Yamashita Futoshi
Published: January 2019

Earthquake rupture propagation along a fault interface depends on the governing friction law. Although a variety of friction laws have been proposed based on measurements made in the lab, uncertainty remains regarding to what extent those measurements capture the true rupture properties. By comparing laboratory earthquakes with numerically simulated ruptures, we find that certain properties inside the rupture front may not always be accessible to direct measurements in the real world, due to a lack of resolution caused by the shrinking size of rupture front zone (Lorentz contraction). Instead, we propose an indirect method to robustly estimate rupture properties of laboratory earthquakes, by simultaneously fitting both the trajectory of rupture front and the detailed strain waveform shape using numerical synthetics. Under the current data resolution and on the basis of a slip‐weakening friction model, our method can provide upper bound constraints on slip‐weakening distance, in addition to regular constraints on fracture energy. Application of this new method to 26 laboratory earthquakes shows that rupture properties (directivity, propagation speed, fracture energy, and frictional strength) can fluctuate over earthquake cycles. Post hoc examination further suggests that our direct measurements largely reflect the deformation features outside the rupture front. As the same issue on the feasibility of direct measurements inside the rupture front may exist in other studies, our work questions the accuracy of previously derived friction laws, addresses the need for calibrating measurement location and resolution, and provides a means for examining the self‐consistency of estimated rupture properties.
Land Surface Processes Create Patterns in Atmospheric Residence Time of Water
Authors: Tuinenburg O. A. , van der Ent R. J.
Published: January 2019

Recent studies determined the residence time of moisture in the atmosphere to be 8–10 days but with large spatial and temporal differences. An unexplained daily cycle in the probability density function (PDF) of the residence time of land evaporation was observed, which was not present for oceanic evaporation. Moreover, the PDF of atmospheric residence time of oceanic evaporation was found to be a monotonically decreasing, while for land evaporation, this function had increasing probabilities during the first few days and monotonically decreasing probabilities thereafter. This research determines the causes of (I) the daily cycle in this PDF and (II) the shape of the atmospheric residence time PDF. The strong daily cycle in the residence time PDF using ERA‐Interim is attributed to the fact that the evaporation and precipitation have the same diurnal cycle in ERA‐Interim. Therefore, evaporation entering the atmosphere has the highest probability of returning to the land surface as precipitation at the same moment during the day but possibly a number of days later. Interestingly, this diurnal cycle was almost absent in the simulations forced with GLDAS surface fluxes. Therefore, we conclude that the previously found daily cycle in the atmospheric residence time PDF is due to differences in the diurnal cycles of precipitation in the underlying data sets. Transpiration causes the increasing probabilities during the first days, while bare soil evaporation and canopy interception typically have a monotonically decreasing PDF. Therefore, we conclude that transpiration causes the largest differences in atmospheric residence time between ocean and land evaporation.
A Resampling Approach for Correcting Systematic Spatiotemporal Biases for Multiple Variables in a Changing Climate
Authors: Mehrotra R. , Sharma A.
Published: January 2019

Systematic biases in climate model simulations are commonly addressed using univariate bias correction algorithms that involve matching of mean, variance, and quantiles. These approaches work well for a single variable and location and effectively mimic the observed temporal structure in the corrected series. The intervariable, interspace, and high‐ or low‐frequency temporal dependencies that characterize observed hydrological records are often left untouched and lead to substantial biases in applications such as catchment modeling where their correct representation is critical. In the approach presented here, changes in the dependence attributes are ascertained by resampling of the historical ranks into what these might resemble in the future. The proposed approach is not limited in terms of the number of variables, grid points in space, and the time scale considered. Most importantly, it maintains the shift in dependence and other attributes between the current and the future climate as ascertained by a climate model. The approach is illustrated using daily time series of temperature, precipitation, relative humidity, and wind speed simulated by a regional climate model at 8,910 grid points over Australia. Spatial, temporal, and cross‐variable dependence attributes of the corrected simulations at daily and aggregated time scales are compared against quantile mapping and substantial improvements in performance identified. Resampling of corrected ranks offers a very simple, flexible, and effective general purpose multivariate, multitime, and multilocation bias correction alternative for current and future climate. As the approach works in three dimensions, space, time, and variables, it is denoted as 3DBC, or three‐dimensional bias correction.
The biogenic amines putrescine and cadaverine show in vitro cytotoxicity at concentrations that can be found in foods
Authors: del Rio Beatriz , Redruello Begoña , Linares Daniel M. , Ladero Victor , Ruas-Madiedo Patricia , Fernandez Maria , Martin M. Cruz , Alvarez Miguel A.
Published: January 2019

Putrescine and cadaverine are among the most common biogenic amines (BA) in foods, but it is advisable that their accumulation be avoided. Present knowledge about their toxicity is, however, limited; further research is needed if qualitative and quantitative risk assessments for foods are to be conducted. The present work describes a real-time analysis of the cytotoxicity of putrescine and cadaverine on intestinal cell cultures. Both BA were cytotoxic at concentrations found in BA-rich foods, although the cytotoxicity threshold for cadaverine was twice that of putrescine. Their mode of cytotoxic action was similar, with both BA causing cell necrosis; they did not induce apoptosis. The present results may help in establishing legal limits for both putrescine and cadaverine in food.
Systems Biology Approach to Identify Novel Genomic Determinants for Pancreatic Cancer Pathogenesis
Authors: Khatri Indu , Ganguly Koelina , Sharma Sunandini , Carmicheal Joseph , Kaur Sukhwinder , Batra Surinder K. , Bhasin Manoj K.
Published: January 2019

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with a 5-year survival rate of <8%. Its dismal prognosis stems from inefficient therapeutic modalities owing to the lack of understanding about pancreatic cancer pathogenesis. Considering the molecular complexity and heterogeneity of PDAC, identification of novel molecular contributors involved in PDAC onset and progression using global “omics” analysis will pave the way to improved strategies for disease prevention and therapeutic targeting. Meta-analysis of multiple miRNA microarray datasets containing healthy controls (HC), chronic pancreatitis (CP) and PDAC cases, identified 13 miRNAs involved in the progression of PDAC. These miRNAs showed dysregulation in both tissue as well as blood samples, along with progressive decrease in expression from HC to CP to PDAC. Gene-miRNA interaction analysis further elucidated 5 miRNAs (29a/b, 27a, 130b and 148a) that are significantly downregulated in conjunction with concomitant upregulation of their target genes throughout PDAC progression. Among these, miRNA-29a/b targeted genes were found to be most significantly altered in comparative profiling of HC, CP and PDAC, indicating its involvement in malignant evolution. Further, pathway analysis suggested direct involvement of miRNA-29a/b in downregulating the key pathways associated with PDAC development and metastasis including focal adhesion signaling and extracellular matrix organization. Our systems biology data analysis, in combination with real-time PCR validation indicates direct functional involvement of miRNA-29a in PDAC progression and is a potential prognostic marker and therapeutic candidate for patients with progressive disease.
Internal surface electric charge characterization of mesoporous silica
Authors: Sen Tumcan , Barisik Murat
Published: January 2019

Mesoporous silica is an emerging technology to solve problems of existing and to support projected revolutionary applications ranging from targeted drug delivery to artificial kidney. However, one of the major driving mechanisms, electric charging of internal mesoporous surfaces, has not been characterized yet. In the nanoscale confinements of mesoporous structures made of pore throats and pore voids, surface charges diverge from existing theoretical calculations and show local variation due to two occurrences. First, when the size of pore throat becomes comparable with the thickness of ionic layering forming on throats’ surfaces, ionic layers from opposite surfaces overlap so that ionic concentration on the surface becomes different than Boltzmann distribution predicts, and there will no longer be an equilibrium of zero electric potential at pore throat centers. Second, when this non zero potential inside throats becomes different than the potential of pore voids, ionic diffusion from void to throat creates axial ionic variation on surfaces. For such a case, we performed a pore level analysis on mesoporous internal surface charge at various porosities and ionic conditions. Pore parameters strongly affected the average internal charge which we characterized as a function of overlap ratio and porosity, first time in literature. Using this, a phenomenological model was developed as an extension of the existing theory to include nano-effects, to predict the average mesoporous internal surface charge as a function of EDL thickness, pore size and porosity.
The brittle-ductile transition in active volcanoes
Authors: Parisio Francesco , Vinciguerra Sergio , Kolditz Olaf , Nagel Thomas
Published: January 2019

Contrasting deformation mechanisms precede volcanic eruptions and control precursory signals. Density increase and high uplifts consistent with magma intrusion and pressurization are in contrast with dilatant responses and reduced surface uplifts observed before eruptions. We investigate the impact that the rheology of rocks constituting the volcanic edifice has on the deformation mechanisms preceding eruptions. We propose a model for the pressure and temperature dependent brittle-ductile transition through which we build a strength profile of the shallow crust in two idealized volcanic settings (igneous and sedimentary basement). We have performed finite element analyses in coupled thermo-hydro-mechanical conditions to investigate the influence of static diking on the local brittle-ductile transition. Our results show that in active volcanoes: (i) dilatancy is an appropriate indicator for the brittle-ductile transition; (ii) the predicted depth of the brittle-ductile transition agrees with the observed attenuated seismicity; (iii) seismicity associated with diking is likely to be affected by ductile deformation mode caused by the local temperature increase; (iv) if failure occurs within the edifice, it is likely to be brittle-dilatant with strength and stiffness reduction that blocks stress transfers within the volcanic edifice, ultimately damping surface uplifts.
Metabolome and transcriptome-wide effects of the carbon storage regulator A in enteropathogenic Escherichia coli
Authors: Berndt Volker , Beckstette Michael , Volk Marcel , Dersch Petra , Brönstrup Mark
Published: January 2019

The carbon storage regulator A (CsrA) is a conserved global regulatory system known to control central carbon pathways, biofilm formation, motility, and pathogenicity. The aim of this study was to characterize changes in major metabolic pathways induced by CsrA in human enteropathogenic Escherichia coli (EPEC) grown under virulence factor-inducing conditions. For this purpose, the metabolomes and transcriptomes of EPEC and an isogenic ∆csrA mutant derivative were analyzed by untargeted mass spectrometry and RNA sequencing, respectively. Of the 159 metabolites identified from untargeted GC/MS and LC/MS data, 97 were significantly (fold change ≥ 1.5; corrected p-value ≤ 0.05) regulated between the knockout and the wildtype strain. A lack of csrA led to an accumulation of fructose-6-phosphate (F6P) and glycogen synthesis pathway products, whereas metabolites in lower glycolysis and the citric acid cycle were downregulated. Associated pathways from the citric acid cycle like aromatic amino acid and siderophore biosynthesis were also negatively influenced. The nucleoside salvage pathways were featured by an accumulation of nucleosides and nucleobases, and a downregulation of nucleotides. In addition, a pronounced downregulation of lyso-lipid metabolites was observed. A drastic change in the morphology in the form of vesicle-like structures of the ∆csrA knockout strain was visible by electron microscopy. Colanic acid synthesis genes were strongly (up to 50 fold) upregulated, and the abundance of colanic acid was 3 fold increased according to a colorimetric assay. The findings expand the scope of pathways affected by the csrA regulon and emphasize its importance as a global regulator.
Peptidoglycan binding protein (PGBP)-modified magnetic nanobeads for efficient magnetic capturing of Staphylococcus aureus associated with sepsis in blood
Authors: Lim Jaewoo , Choi Jongmin , Guk Kyeonghye , Son Seong Uk , Lee Do Kyung , Yeom Soo-Jin , Kang Taejoon , Jung Juyeon , Lim Eun-Kyung
Published: January 2019

Peptidoglycan-binding protein-modified magnetic nanobeads (PGBP-MNBs) were prepared for efficient magnetic capturing of Staphylococcus aureus (S. aureus), which is associated with sepsis, using the binding affinity of PGBP for the peptidoglycan (PG) layer on S. aureus. These PGBP-MNBs can simply capture S. aureus in plasma within 1 hr or even 15 min. Importantly, they also can capture various types of Gram-positive bacteria, such as Bacillus cereus and methicillin-resistant and methicillin-susceptible S. aureus (MRSA and MSSA). We believe that PGBP-based systems will be used to develop diagnostic systems for Gram-positive bacteria-related diseases.
Genetically distinct glioma stem-like cell xenografts established from paired glioblastoma samples harvested before and after molecularly targeted therapy
Authors: Tanaka Shota , Luk Samantha , Kiyokawa Juri , Onozato Maristela L. , Iafrate A. John , Shah Khalid , Martuza Robert L. , Rabkin Samuel D. , Batchelor Tracy T. , Cahill Daniel P. , Chi Andrew S. , Wakimoto Hiroaki
Published: January 2019

Intratumoural heterogeneity underlies tumour escape from molecularly targeted therapy in glioblastoma. A cell-based model preserving the evolving molecular profiles of a tumour during treatment is key to understanding the recurrence mechanisms and development of strategies to overcome resistance. In this study, we established a matched pair of glioblastoma stem-like cell (GSC) cultures from patient glioblastoma samples before and after epidermal growth factor receptor (EGFR)-targeted therapy. A patient with recurrent glioblastoma (MGG70R) harboring focal, high-level EGFR amplification received the irreversible EGFR tyrosine kinase inhibitor dacomitinib. The tumour that subsequently recurred (MGG70RR) showed diploid EGFR, suggesting inhibitor-mediated elimination of EGFR-amplified tumour cells and propagation of EGFR non-amplified cell subpopulations. The MGG70R-GSC line established from MGG70R formed xenografts retaining EGFR amplification and EGFR overexpression, while MGG70RR-GSC established from MGG70RR generated tumours that lacked EGFR amplification and EGFR overexpression. MGG70R-GSC-derived intracranial xenografts were more proliferative than MGG70RR-GSC xenografts, which had upregulated mesenchymal markers, mirroring the pathological observation in the corresponding patient tumours. In vitro MGG70R-GSC was more sensitive to EGFR inhibitors than MGG70RR-GSC. Thus, these molecularly distinct GSC lines recapitulated the subpopulation alteration that occurred during glioblastoma evasion of targeted therapy, and offer a valuable model facilitating therapeutic development for recurrent glioblastoma.