bluuebunny/crossref_metadata_2025 huggingface dataset:
Yeast genetic interaction screen of human genes associated with amyotrophic lateral sclerosis: identification of MAP2K5 kinase as a potential drug target
Authors: Jo Myungjin , Chung Ah Young , Yachie Nozomu , Seo Minchul , Jeon Hyejin , Nam Youngpyo , Seo Yeojin , Kim Eunmi , Zhong Quan , Vidal Marc , Park Hae Chul , Roth Frederick P. , Suk Kyoungho
Published: June 2017

To understand disease mechanisms, a large-scale analysis of human–yeast genetic interactions was performed. Of 1305 human disease genes assayed, 20 genes exhibited strong toxicity in yeast. Human–yeast genetic interactions were identified by en masse transformation of the human disease genes into a pool of 4653 homozygous diploid yeast deletion mutants with unique barcode sequences, followed by multiplexed barcode sequencing to identify yeast toxicity modifiers. Subsequent network analyses focusing on amyotrophic lateral sclerosis (ALS)-associated genes, such as optineurin (OPTN) and angiogenin (ANG), showed that the human orthologs of the yeast toxicity modifiers of these ALS genes are enriched for several biological processes, such as cell death, lipid metabolism, and molecular transport. When yeast genetic interaction partners held in common between human OPTN and ANG were validated in mammalian cells and zebrafish, MAP2K5 kinase emerged as a potential drug target for ALS therapy. The toxicity modifiers identified in this study may deepen our understanding of the pathogenic mechanisms of ALS and other devastating diseases.
Adaptive response prediction for aerodynamic shape optimization
Authors: Leifsson Leifur , Koziel Slawomir
Published: June 2017

Purpose

The purpose of this paper is to reduce the overall computational time of aerodynamic shape optimization that involves accurate high-fidelity simulation models.

Design/methodology/approach

The proposed approach is based on the surrogate-based optimization paradigm. In particular, multi-fidelity surrogate models are used in the optimization process in place of the computationally expensive high-fidelity model. The multi-fidelity surrogate is constructed using physics-based low-fidelity models and a proper correction. This work introduces a novel correction methodology – referred to as the adaptive response prediction (ARP). The ARP technique corrects the low-fidelity model response, represented by the airfoil pressure distribution, through suitable horizontal and vertical adjustments.

Findings

Numerical investigations show the feasibility of solving real-world problems involving optimization of transonic airfoil shapes and accurate computational fluid dynamics simulation models of such surfaces. The results show that the proposed approach outperforms traditional surrogate-based approaches.

Originality/value

The proposed aerodynamic design optimization algorithm is novel and holistic. In particular, the ARP correction technique is original. The algorithm is useful for fast design of aerodynamic surfaces using high-fidelity simulation data in moderately sized search spaces, which is challenging using conventional methods because of excessive computational costs.
Algal bloom prediction by support vector machine and relevance vector machine with genetic algorithm optimization in freshwater reservoirs
Authors: Wang Yanjie , Xie Zhengchao , Lou InChio , Ung Wai Kin , Mok Kai Meng
Published: June 2017

Purpose

The purpose of this paper is to examine the applicability and capability of models based on a genetic algorithm and support vector machine (GA-SVM) and a genetic algorithm and relevance vector machine (GA-RVM) for the prediction of phytoplankton abundances associated with algal blooms in a Macau freshwater reservoir, and compare their performances with an artificial neural network (ANN) model.

Design/methodology/approach

The hybrid models GA-SVM and GA-RVM were developed for the optimal control of parameters for predicting (based on the current month’s variables) and forecasting (based on the previous three months’ variables) phytoplankton dynamics in a Macau freshwater reservoir, MSR, which has experienced cyanobacterial blooms in recent years. There were 15 environmental parameters, including pH, SiO2, alkalinity, bicarbonate (HCO3−), dissolved oxygen (DO), total nitrogen (TN), UV254, turbidity, conductivity, nitrate (NO3−), orthophosphate (PO43−), total phosphorus (TP), suspended solids (SS) and total organic carbon (TOC) selected from the correlation analysis, with eight years (2001-2008) of data for training, and the most recent three years (2009-2011) for testing.

Findings

For both accuracy performance and generalized performance, the ANN, GA-SVM and GA-RVM had similar predictive powers of R2 of 0.73-0.75. However, whereas ANN and GA-RVM models showed very similar forecast performances, GA-SVM models had better forecast performances of R2 (0.862), RMSE (0.266) and MAE (0.0710) with the respective parameters of 0.987, 0.161 and 0.032 optimized using GA.

Originality/value

This is the first application of GA-SVM and GA-RVM models for predicting and forecasting algal bloom in freshwater reservoirs. GA-SVM was shown to be an effective new way for monitoring algal bloom problem in water resources.
Reducing computational time of cohesionless discrete simulations based on particle clusters
Authors: Oldal Istvan , Safranyik Ferenc , Keppler Istvan
Published: June 2017

Purpose

The purpose of this study is the reduction of computational time demand of discrete element based modeling.

Design/methodology/approach

The methodology is the systematic changing of particle size and micromechanical parameters to reduce computational time requirements.

Findings

In some cases, the computational demand of discrete simulations can be reduced to about 95 per cent.

Originality/value

Based on the results and demonstrated methodology, the enormous computational time demand of discrete element-based modeling can be reduced significantly.
A moral case for universal healthcare for runaway and homeless youth
Authors: Harpin Scott B. , Elliott April S. , Auerswald Colette L.
Published: June 2017

Purpose

Runaway and homeless youth (RHY) are among the most vulnerable youth globally. The United Nations Convention on the Rights of the Child (UNCRC) states that all children have the right to the highest level of health, and that universal healthcare rights are afforded to RHY and all children. Social determinants of health (SDH) are universal factors that frame the experiences of RHY as facilitators or barriers for accessing healthcare. The purpose of this paper is to describe practical best approaches, and policy recommendations, for improving clinical care systems to make healthcare more accessible to RHY.

Design/methodology/approach

The authors describe and apply an adapted socio-ecological framework that includes SDH specific to RHY around the globe.

Findings

There are multiple and complex factors in the social ecology of RHY that determine their chances of accessing healthcare. While many intrapersonal reasons for homelessness are the same globally, systems of care vary by country and by developing/developed country status. Structurally competent care systems offer a new lens for how to best provide care to RHY to take into account SDH and the unique needs of RHY.

Originality/value

The UNCRC serves as a moral guide and frame of universal child healthcare provision for countries around the world. The authors uniquely argue for UNCRC, tailored-SDH, and care delivered in a structurally competent manner to make a moral case for both physical and mental health for all RHY.
Comparisons of tribological properties between laser and drilled dimple textured surfaces of medium carbon steel
Authors: Shi Chenchun , Yu Aibing , Wu Jianzhao , Niu Weiyang , Wang Yanlin
Published: June 2017

Purpose

The study aims to compare tribological properties between laser dimple textured surface and drilled dimple textured surface, and to analyze the influence of dimple hardened edges and ability of trapping wear debris on wear properties of dimple textured surfaces.

Design/methodology/approach

Circular textured dimples were produced on AISI 1,045 specimen surfaces using laser surface texturing (LST) and drilled surface texturing (DST) methods. Tribological behaviors of LST, DST and non-textured specimens were studied using ball-on-disc tribo-tester. Metallographic structures, dimples and worn surface morphologies were observed using a three-dimensional digital microscope. Hardnesses of substrate and dimple edges were measured.

Findings

There was no obvious difference in wear and friction coefficients between LST and DST specimens. Hardnesses of laser dimple edges were much higher than that of drilled dimple edges and specimen substrate. The hardened materials of laser dimple edge included recast zone and heat affect zone. Laser dimple was cone-shaped and drilled dimple was cylinder-shaped. Drilled dimple had a better ability of trapping wear debris than laser dimple. Non-uniform wear phenomenon occurred on worn surfaces of LST dimple specimens.

Originality/value

The ability of textured dimples to trap wear debris is affected by single dimple volume. Hardened edges of dimples cause non-uniform wear on worn surfaces of LST specimens.
Surfaces with pores: hydrodynamic lubrication
Authors: Burstein Leonid
Published: June 2017

Purpose

This paper aims to assess the hydrodynamic lubrication of two opposing surfaces with identical pores having a semicircular profile. The surfaces are treated with more than one pore that allows clarification of whether there exists interaction between the pores.

Design/methodology/approach

A transient, spatial, one-dimensional model of surfaces with regular pores was developed and applied in the context of fluid lubrication. MATLAB software has been used.

Findings

Calculations show that a lubricating film between two surfaces with pores provides better hydrodynamic conditions in comparison to that on one surface with pores. It was also shown that the pores of one surface act as separate objects and can take into account only the interaction between the pores of the opposite surfaces. In addition, it was found that there are optimum values of the pore radii, gap and pore cell dimensions at which the bearing capacity of the film is maximal.

Practical implications

The computer program used for the pore parameter calculations provided the optimal lubrication.

Originality/value

This is the first study of the lubricating film hydrodynamic behavior of two opposite surfaces with pores having a semicircular profile.
Bony traits and genetics drive intraspecific variation in vertebrate elemental composition
Authors: Durston Daniel J. , El‐Sabaawi Rana W.
Published: June 2017

Interspecific variation in elemental composition is well known and often leads to predictable differences in ecosystem interactions, but little is known about the extent, causes and importance of intraspecific variation in elemental composition. If intraspecific variation is substantial and has a genetic basis, it may underlie an important mechanism of evolutionary interplay with ecology as individuals compensate for evolutionary changes in elemental demand.

To investigate the extent and causes of intraspecific elemental variation in vertebrates, we sampled evolutionary model species Gasterosteus aculeatus (Threespine Stickleback) from 12 locations in British Columbia, Canada. Fish were phenotyped, genotyped for Eda alleles underlying lateral plate variation and assayed for elemental content (C, N, P).

We found stickleback vary widely in elemental composition (2.2%–6.5% P; 3.0–9.4: 1 N:P). Phenotypic models explained the majority of this variation using bony armour traits (pelvis length, lateral plate count), bone mineralization, body size and condition.

Subsequent genetic models found allelic variation at Eda generates a 7%–14% change in whole organism N:P. As Eda allele frequencies are commonly changed through strong natural selection in freshwater habitats, we infer that stickleback elemental composition can evolve rapidly.

Further, as genetics are known to drive variation in many of the other influential traits, we conclude that genetic variation constitutes a major source of variation in the elemental composition of Gasterosteus aculeatus. As such, we find that elemental composition has a large evolutionary potential which may underlie important evo‐eco interactions.

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is available for this article.
Ontogenetic changes in insect herbivory in birch (Betula pubesecens): The importance of plant apparency
Authors: Zverev Vitali , Zvereva Elena L. , Kozlov Mikhail V.
Published: June 2017

Several theories aim at predicting changes in the interactions between plants and herbivores over the lifetime of a plant. Hypotheses based on ontogenetic changes in resource allocation to plant defence and in plant apparency lead to partly opposing predictions regarding the differences in levels of herbivory between juvenile and mature plant individuals.

We tested these predictions by measuring background foliar losses to insects in saplings and mature trees of downy birch (Betula pubescens) in ten sites along a latitudinal gradient from 60° to 69°N in boreal forests of Northern Europe.

The percentage of consumed leaf area increased, and the variation in the levels of herbivory among plant individuals decreased, for tree sizes ranging from small saplings (2–12 cm tall) to large saplings (13–80 cm tall) and then to mature trees (3–18 m tall).

Small saplings had higher foliar quality for insects, as indicated by better performance of leafmining larvae of Eriocrania semipurpurella and by greater specific leaf area, compared with large saplings and mature trees. The average percentage of leaf area consumed from a damaged leaf, which reflects the inducibility of local defence responses to insect damage, did not vary among the birch size classes.

The foliar losses to insects decreased nearly fivefold with an increase in latitude from 60° to 69°N, but the relative differences in these losses among the birch size classes were independent of latitude.

Our findings fit well with the predictions based on a plant apparency hypothesis, but do not support predictions based on ontogenetic changes in resource allocation to plant antiherbivore defences. We conclude that the generally overlooked effects of apparency on plant damage by insects can explain, at least in some cases, the frequently observed lack of correspondence between the levels of plant defences and herbivory.

A plain language summary is available for this article.
Nematodes, exotic earthworms and nitrogen addition: interactions between global change factors lead to cancellation effects
Authors: De Long Jonathan R.
Published: June 2017

Photos from the experiment described in Shao et al. (2017): (a) the endogeic (i.e. earthworms that typically live in the soil, burrowing horizontally to acquire nutrients) earthworm Pontoscolex corethrurus that was added to the plots; (b) P. corethrurus in a quiescence state in response to drought; (c) set‐up of the control plots (i.e. no earthworms, ambient nitrogen) used in this experiment. [Colour figure can be viewed at wileyonlinelibrary.com]

In Focus: Shao, Y., Zhang, W., Eisenhauer, N., Liu, T., Xiong, Y., Liang, C. & Fu, S. (2017) Nitrogen deposition cancels out exotic earthworm effects on plant‐feeding nematode communities. Journal of Animal Ecology, 86, 708–717.

In this issue of Journal of Animal Ecology, Shao et al. (2017) explored how N addition and exotic earthworms interacted to impact on the plant‐feeding nematode community. They demonstrate that exotic earthworm presence alone increased the abundance of less harmful plant‐feeding nematodes and decreased the abundance of the more harmful plant‐feeding nematodes. However, in plots receiving both exotic earthworms and N addition, such earthworm effects on the nematode community were negated. These findings pull focus on the need to simultaneously consider multiple global change factors (e.g. exotic species invasions and N deposition) when making predictions about how such factors might affect above‐ and below‐ground interactions and thereby alter ecosystem function.
Women, weight, poverty and menopause: understanding health practices in a context of chronic disease prevention
Authors: Audet Mélisa , Dumas Alex , Binette Rachelle , Dionne Isabelle J.
Published: June 2017

Socioeconomic inequalities in health persist despite major investments in illness prevention campaigns and universal healthcare systems. In this context, the increased risks of chronic diseases of specific sub‐groups of vulnerable populations should be further investigated. The objective of this qualitative study is to examine the interaction between socioeconomic status (SES) and body weight in order to understand underprivileged women's increased vulnerability to chronic diseases after menopause. By drawing specifically on Pierre Bourdieu's sociocultural theory of practice, 20 semi‐structured interviews were conducted from May to December of 2013 to investigate the health practices of clinically overweight, postmenopausal women living an underprivileged life in Canada. Findings emphasise that poor life conditions undermine personal investment in preventive health and weight loss, showing the importance for policy makers to bring stronger consideration on upstream determinants of health.
Death due to a rare complication of colonoscopy and the potential medicolegal implications
Authors: Thompson Katrina , Stier Michael A.
Published: June 2017

A 64‐year‐old woman was found dead at home after undergoing a screening colonoscopy. At autopsy, 1.9 L of blood was discovered within her abdominal cavity. The only major abnormality was nontraumatic avulsion of the splenic capsule. This was the only identifiable abnormality capable of causing the severe hemoperitoneum and demise of the patient. Although rare, splenic capsule avulsion is a recognized complication of colonoscopy. Many have theorized that it results from excessive traction on the splenocolic ligament resulting in a tear of the splenic capsule. Most patients present within the first 24 hours after the procedure with nonspecific symptoms, and many patients may not seek medical attention. The paucity of the literature in the area of splenic capsular avulsion after colonoscopy reinforces the importance of reporting known cases, and by doing so raise awareness of this rare but devastating complication of an otherwise beneficial screening procedure.
Colorectal endometriosis: Five years’ experience in this enigmatic problem
Authors: Ofkeli Ozcem , Ulas Murat , Oter Volkan , Aksoy Erol , Zengin Neslihan , Ozer Ilter , Bostanci Erdal Birol
Published: June 2017

Aim

Endometriosis primarily affects women of reproductive age, and is responsible for impairing their quality of life. The presence of severe symptoms, including stenosis of the intestinal lumen, diagnostic difficulty (suspicion of malignancy) and intolerance to hormonal therapy, are indications for surgery. Despite numerous studies on endometriosis, there is still considerable controversy about its incidence, pathogenesis, diagnosis and optimal treatment.

Patients and methods

The present retrospective, observational study included 11 patients diagnosed with intestinal endometriosis between January 2009 and December 2013. Demographic data, clinical presentation, diagnostic modalities, localization of the disease and intraoperative data were collected.

Results

The median age of the patients was 43 years (34–63 years). Eight patients had intermittent abdominal pain, seven had change in bowel habits and three had rectal bleeding. Seven patients were operated on for severe stenosis of the intestinal lumen (intestinal obstruction), and three for a suspected malignancy. Postoperatively, all of the patients who underwent resection were free of pain. No patient had any disease recurrence on abdominal ultrasonography or computed tomography images.

Conclusion

Intestinal endometriosis should be considered in female patients of reproductive age presenting with constipation, rectal bleeding and abdominal pain. Repeated inadequate biopsies should also raise suspicion of intestinal endometriosis. Intestinal endometriosis is a rare disease with diagnostic difficulties, and despite medical management, treatment option is usually surgery. However, in patients diagnosed preoperatively with no intestinal obstruction, medical therapy can be tried.
Efficacy of Combined Sous Vide‐Microwave Cooking for Foodborne Pathogen Inactivation in Ready‐to‐Eat Chicory Stems
Authors: Renna Massimiliano , Gonnella Maria , de Candia Silvia , Serio Francesco , Baruzzi Federico
Published: June 2017

There is a variety of different food processing methods, which can be used to prepare ready‐to‐eat foods. However, the need to preserve the freshness and nutritional qualities leads to the application of mild technologies which may be insufficient to inactivate microbial pathogens. In this work, fresh chicory stems were packed under a vacuum in films, which were transparent to microwaves. These were then exposed to microwaves for different periods of time. The application of sous vide microwave cooking (SV‐MW, 900 W, 2450 MHz), controlled naturally occurring mesophilic aerobic bacteria, yeasts and molds for up to 30 d when vacuum‐packed vegetables were stored at 4 °C. In addition, the process lethality of the SV‐MW 90 s cooking was experimentally validated. This treatment led to 6.07 ± 0.7 and 4.92 ± 0.65 log cfu/g reduction of Escherichia coli and Listeria monocytogenes inoculated over the chicory stems (100 g), respectively.

With an initial load of 9 log cfu/g for both pathogens, less than 10 cfu/g of surviving cells were found after 90 s cooking. This shows that short‐time microwave cooking can be used to effectively pasteurize vacuum‐packed chicory stems, achieving >5 log cfu/g reduction of E. coli and L. monocytogenes.
Late Triassic Intraoceanic Arc Aystem within Neotethys: Evidence from Cumulate Hornblende Gabbro in Gangdese Belt, South Tibet
Authors: MA Xuxuan , YI Zhiyu , XU Zhiqin
Published: June 2017

The Neotethys plays an important role in shaping the Gangdese magmatic belt, southern Tibet. However, the initial time of spreading and subduction of the Neotethys remains contentious.

In this study, a suite of late Triassic cumulate hornblende gabbro was identified in the southern margin of the Gangdese magmatic belt. The gabbro exhibits cumulate structure, with hornblende and plagioclase as the primary mineral phases. Isotopic data indicate a hydrous magma source derived from a depleted mantle wedge that has been modified by slab dehydration. Geochemical discriminations suggest that the gabbro was formed in an intraoceanic arc setting, with crystallization ages of ca. 220–213 Ma. Hornblende, hornblende‐lagioclase and ilmenite thermometers reveal that the crystallization temperature of 900–750 °C for the gabbro. Hornblende and hornblende‐plagioclase geobarometers yield an emplacement depth at ca. 14.5–19.5 km. This gabbro constitutes a line of evidence for an intraoceanic arc magmatism that is coeval with the counterparts in the southern Turkey, revealing an intraoceanic subduction system within the Neotethys from west to east in the Late Triassic and that the oceanization of the Neotethys was much earlier than previous expectation.
Overview of the Geology of Cuba
Authors: ITURRALDE‐VINENT Manuel A.
Published: June 2017

Cuba is the largest island in the Greater Antilles (GA) and has been part of the North American Plate (NOAM) since Upper Eocene time. It is separated from other GA islands by the North Caribbean Transform Fault System which defines the present boundary between the NOAM and the Caribbean Plate (CARIB).

The GA began to form ∼135 Ma ago, after the breakup of Pangea, in the leading edge of CARIB, due to subduction of Proto‐Caribbean lithosphere (NOAM) beneath CARIB until collision with the Bahamian platform in the Middle to Late Eocene time (∼48 to 40 Ma). Between the Maastrichtian and the Late Eocene the Cayman spreading ridge and the Oriente transform formed and western CARIB was transferred to NOAM.

The geology of Cuba is dominated by three lithotectonic units, which reflects its evolution as a Cretaceous‐Paleogene convergent margin: (1) deformed (para)autochthonous NOAM Jurassic and Cretaceous continental margin and basin sections and Paleocene‐Eocene synorogenic foredeep; (2) ophiolite complexes and serpentinite mèlanges and ∼135 to 47 Ma magmatic arc suite interbedded with or overlain by Latest Cretaceous‐Paleogene synorogenic strata; and (3) (neo)autochthonous late Upper Eocene to Recent deposits which unconformably overlie the two older units.
The Petrology and Geochemistry of Listwaenite in the Sartohay Ophiolitic Melange of West Junggar, Xinjiang, China
Authors: QIU Tian , ZHU Yongfeng
Published: June 2017

The west Junggar, located in the eastern part of Balkash‐Junggar tectonic province, is a major component of the core of the Central Asian metallogenic region. This area is characterized by occurrences of ophiolitic mélanges, such as the Sartohay ophiolitic mélange in the NE and the Tangbale ophiolitic mélange in the west. As a hydrothermal alteration product of serpentinite in the Sartohay ophiolitic mélange, listwaenite lenses are gold‐mineralized and crop out on surface in the ophiolitic mélange via weathering of exhumated hanging wall of fault zone. Listwaenite is mainly composed of magnesite, quartz, dolomite, and trace amounts of mariposite, chromian spinel, talc and sulfide. A vertical thermal gradient model for the hydrothermal alteration shows that serpentinite would first be transformed to talc schist, then into listwaenite as the ophiolite slices continued to rise along shear zone, with XCO2, oxygen and sulfur fugacity increase and temperature decrease. Both serpentine and magnetite were progressively destroyed during the transformation from serpentinite to talc schist, and completely vanished in listwaenite, while mariposite generated in weakly deformed to mylonitized listwaenite. Concentrations of most trace elements including high field strength elements and metallogenic elements, increasing from undeformed, through weakly deformed, to mylonitized listwaenite, show a positive correlation with deformation degree and content of apatite, rutile, monazite, zircon and sulfide in listwaenite. The shear zone served as pathways for percolation and accumulation of fluid and trace elements during the metasomatism from serpentinite to listwaenite. Compared to undeformed listwaenite, mylonitized listwaenite will be more favorable to be fractured and brecciated due to more intense shearing, which caused strong metasomatic reaction and then induced trace element‐bearing mylonitized listwaenite.
A Forearc (Guleman, Elaziğreve;) Ophiolite: Evidence from Peridotite Mineral Geochemistry
Authors: RIZELI Mustafa Eren , BEYARSLAN Melahat , BINGÖL A. Feyzi
Published: June 2017

The Guleman ophiolite, one of the most important ophiolitic massifs of the Southeast Anatolian Ophiolitic Belt, consists of a core of serpentinized mantle rocks overlain by an ultramafic sequence, layered and isotropic gabbro, and sheeted dykes. The ophiolite structurally overlies the Lower Miocene Lice Formation and is overlain by young sandstones and shales of the Upper Maashtrichtian‐Lower Eocene Hazar Complex and Middle Eocene Maden Complex. The Guleman ophiolite tectonically overlain by Precambrian to Upper Triassic Bitlis metamorphic massif.

The mantle peridotites compose mainly of fresh and in place serpentinized harzburgite tectonite with local bands and lenses of dunites with large‐sized chromitite pods. The Guleman peridotites commonly show porphyroclastic texture, high‐temperature fabrics such as kink‐bands in olivines.

According to microprobe analyses, the harzburgite and dunite have low CaO and Al2O3 abundance similar to Mariana forearc, and their average Cr‐ (=Cr/(Cr+Al) atomic) ratio of Cr‐spinelsis surprisingly high (>0.63) besides Fo content of olivine is between 90.9 to 92.3 in peridotites. According to Mg# (Mg/(Mg+Fe2+)) versus Cr# in spinel diagram, the degree of partial melting is higher than 35% and spinel values plot in the forearc peridotites field. The Gulemanharzburgites have low CaO, Al2O3 and TiO2 contents in orthopyroxene and clinopyroxene lammelles, resembling those of depleted harzburgites from modern forearcs and different from moderately depleted abyssal peridotites.

Consequently, we propose that the Guleman peridotites form in a forearc setting during the subduction initiation that developed as a result of northward subduction of the southern branch of the Neo‐Tethys in response to the convergence between Arabian and Anatolian plates.
Relic Oceanic Crust at Sub‐Arc Depth: An Example from UHP Eclogites Enclosed in Serpentinites from the Southwestern Tianshan, China
Authors: SHEN Tingting , ZHANG Lifei , HERMANN Joerg , LIU Fenglin
Published: June 2017

Ultra‐high pressure (UHP) eclogites that derive from subducted oceanic crust are rarely found at the Earth's surface because they need to be enclosed in a buoyant host rock such as serpentinites that facilitate exhumation (Hermann et al., 2000; Guillot et al., 2001). Under normal subduction geotherms, serpentinites break down just before UHP conditions are reached and therefore most of the exhumed eclogites representing subducted oceanic crust formed under fore‐arc conditions. We investigated eclogite blocks enclosed into serpentinites that occur in the southwestern Tianshan oceanic subduction, China. A previous study proved that the serpentinites derive from altered oceanic crust and experienced UHP metamorphism at low temperatures of 510–530°C (Shen et al., 2015).

Three relatively fresh eclogite samples were studied in detail. Sample 129–7 shows the retrograde mineral assemblage of amphibole + biotite + albite + chlorite + minor titanite and peak metamorphic relics of omphacite + garnet ± chlorite. Sample C107‐23 is mainly composed of amphibole + albite + chlorite + zoisite + muscovite + minor titanite as a retrograde assemblage and garnet + phengite as the peak metamorphic relics with omphacite only found as inclusions in garnet. Similar to sample C107‐23, sample C11066 preserves large‐grained euhedral to subhedral garnet relics with omphacite inclusions, and epidote, diopside, amphibole, muscovite, chlorite, albite and biotite are in the matrix belong to the retrograde assemblage. These three retrograde eclogite samples were modelled using thermodynamic calculations in the MnNCKFMSHO (MnO‐Na2O‐CaO‐K2O‐FeO‐MgO‐Al2O3‐SiO2‐H2O‐Fe2O3) system. Based on the peak assemblage of omphacite+garnet and the crossing of the grossular and pyrope isopleths in garnet, peak P‐T conditions of ∼460–470 °C, 28–29 kbar (129–7), 450–500 °C, 28–35 kbar (C107–23), ∼475–505 °C, 26–29 kbar (C11066) were calculated. The retrograde assemblages indicate near isothermal decompression resulting in a clockwise P‐T evolution of these eclogites. The peak metamorphic pressures at 500°C are well within UHP conditions (coesite stability field) and are within error the same as peak conditions of the host serpentinites (Shen et al., 2015). This provides evidence that eclogites and serpentinites shared the same evolution. We infer that the subducted low‐density serpentinites were assembled with the high‐density eclogites during subdution and helped the latter to exhume back to the surface. The studied eclogites thus represent rare examples of relics of oceanic crust that was subducted to sub‐arc depth.
Fe Isotope Geochemistry of Hydrothermal Fe Exhalites
Authors: SUN Jian , ZHU Xiangkun , LI Zhihong
Published: June 2017

The sediments atop the sequence of ophiolite usually contain Fe(‐Mn‐Si) exhalites, chemical sediments that are mainly composed of amorphous Fe‐Mn oxy‐hydroxides and chert/jasper. They were precipitated from hydrothermal fluids produced by deep leaching of basalt particularly during volcano activity or seafloor spreading. These hydrothermal Fe exhalites provide a good record for the depositional environment and the ocean environment as well.

A well‐preserved Phanerozoic Fe deposit, Motuosala Fe‐Mn deposit, resulted from hydrothermal exhalation, was investigated for its trace element and Fe isotope geochemistry. The deposit is located in Xinjiang province, China and is hosted in a suit of Carboniferous volcano‐sedimentary clastic rocks. The Fe deposit is mainly composed of massive hematite Fe oreand banded hematite‐jasper ore. The hematite ore/band and jasper band were subjected to be analyzed. They are both composed mainly of Fe2O3 and SiO2, with very low contents of Al2O3 and TiO2 (>1%), indicating they were chemical precipitates with little detrital contamination. They both show slightly LREE depleted or near flat PAAS‐normalised REE patterns, with positive Eu anomalies and Y anomolies, indicating that they were sourced from a mixture of high‐temperature fluids and seawater. Compared to the hematite Fe ore/band, the jasper band shows higher EuSN/EuSN* but lower Y/Ho values. δ56Fe values for the hematite Fe ores are clustered around −0.3‰, similar to those for high‐temperature fluids. The jasper samples show heavier Fe isotope compositions varying from −0.1‰ to 0.5‰, indicating that they were resulted from partial Fe precipitation. For all samples, δ56Fe values are related to Y/Ho and EuSN/EuSN* values.

The results indicate that the hematite Fe ore and jasper were deposited in different environments. The jasper was deposited in a more anoxic condition with higher hydrothermal fluids/seawater ratio, probably when the hydrothermal activity was more intense; while the hematite Fe ore was deposited in a more oxic condition with lower hydrothermal fluids/seawater ratio, probably when the hydrothermal activity was weaker.
Positioning the Southern Margin of Asia Prior to Its Collision with India: Paleomagnetic Constraints from Late Cretaceous Dykes in Gangdise Belt
Authors: YI Zhiyu , MA Xuxuan
Published: June 2017

The pre‐collisional southern margin of Asia can be restored using paleomagnetic data from late Cretaceous rocks from the Lhasa terrane. However, the available data are based either on the red beds or on the intercalated thin layers of lava flows, both of which had been involved in strongly folding. Recent studies show clear evidence for the possibility of serious overprint hence the data could not be reliably used for tectonic interpretation. We report paleomagnetic data from diorite dykes and the grano‐diorite country rock in the Gandise belt near the city of Lhasa. U–Pb isotopic dating indicates the intrusive rocks have an age of ∼82–86 Ma. Fifteen sites yield acceptable ChRM directions which pass a reversal test. SEM and light microscope observations show primary intergrowth relationship between magnetite and other minerals within the thin sections. AMS measurement defines a primary magma flow fabric for the intruded dykes and the country rocks. All the characteristics support that the ChRMs are primary. The paleomagnetic pole calculated from the remanence of the dykes and the country rocks yields a paleolatitude of ∼14°N which provide a reliable constraint for the southern margin of Asia near Lhasa. Furthermore, the recorded declination shows significant counterclockwise rotation of ∼20° for the sampling location relative to the north. In consideration of the strike and tectonic setting of the dykes, the strike of the southern margin of Asia is restored which is compatible with the hypothesis of a quasi‐linear margin of Eurasia prior to its collision with India.
The Beila Ophiolite from the Bangong‐Nujiang Suture Zone, Northern Tibetan Plateau
Authors: ZHAI Qingguo , TANG Yue , HU Peiyuan , XIAO Xuchang , WANG Haitao
Published: June 2017

The Beila ophiolite is located in the middle part of the Bangong‐Nujiang suture zone, northern Tibetan plateau. It is a complete ophiolite suite, and plays a key role in understanding the evolution of the Bangong‐Nujiang suture zone, as well as the Meso‐Tethys Ocean. The Beila ophiolite was composed of peridotite, serpentinite, gabbro, pillow basalt, and minor rodingite. Peridotites comprise mainly medium– to coarse–grained serpentinized harzburgites and minor plagioclase‐bearing lherzolites and dunites. There are some felsic‐ultramafic dykes within the peridotite and they are mainly pegmatoidal pyroxenites, coarse to fine‐grained gabbros, and diabases. Gabbros included isotropic and cumulate gabbros, and they commonly contain minor pegmatoidal gabbros veins. Pillow basalts and basaltic andesites overlaid on the margin of the serpentinized peridotites. Rodingite occurs as lenses and/or dykes within the host serpentinized peridotites. Zircon SHRIMP U–Pb dating for two rodingite samples yielded the ages ranging from 172 to 164 Ma. Whole‐rock geochemical and zircon Hf isotopic data show that the Beila ophiolite shows SSZ‐type ophiolite affinity. Finally, we suggest that the Beila ophiolite was generated in an initial subduction process at the middle Jurassic (164–172 Ma).
Ready, willing, and able: the role of cannabis use opportunities in understanding adolescent cannabis use
Authors: Burdzovic Andreas Jasmina , Bretteville‐Jensen Anne Line
Published: June 2017

Aims

To examine adolescent cannabis use—both at national and individual levels—by deconstructing it into its necessary conditions of realistic use opportunities and willingness to use the drug given such opportunities.

Design

Nationally representative, repeated cross‐sectional survey.

Setting

Norway.

Participants

A total of 8818 16‐year‐olds who participated in the European School Survey Project on Alcohol and Other Drugs (ESPAD) in 2007, 2011, and 2015.

Measurements

Adolescent reports concerning their life‐time ‘cannabis use’ and ‘possibilities to use cannabis’ were used to assess: (a) overall cannabis use, (b) exposure to realistic cannabis use opportunities, and (c) cannabis use among those exposed to use opportunities. Logistic regression models were used to estimate national trends since 2007 in these indicators, and to identify individual‐level factors associated with cannabis use versus non‐use among youth exposed to concrete use opportunities.

Findings

Prevalence of life‐time cannabis use remained stably low, averaging 6.4% across the three surveys. Life‐time exposure to cannabis use opportunities decreased [odds ratio (OR)ESPAD assessment = 0.90, 95% confidence interval (CI) = 0.84–0.97, P = 0.006], yet cannabis use among adolescents with such opportunities increased significantly (ORESPAD assessment = 1.17, 95% CI = 1.03–1.34, P = 0.02) since 2007. After controlling for a range of other risk factors, abstinence from alcohol intoxication and cigarette use, as well as the perceptions of even minimal cannabis use as risky remained the factors most robustly associated with lower likelihood of cannabis use among youth with realistic use opportunities.

Conclusions

Approaches accounting for realistic use opportunities proved critical in our understanding of underage cannabis use, both at the national and individual level, and may be informative for development of prevention strategies in the era of cannabis liberalization. In addition, delineation of realistic opportunities from behaviours conditioned upon such opportunities is generalizable to a range of public health issues.
Loose regulation of medical marijuana programs associated with higher rates of adult marijuana use but not cannabis use disorder
Authors: Williams Arthur Robin , Santaella‐Tenorio Julian , Mauro Christine M. , Levin Frances R. , Martins Silvia S.
Published: June 2017

Background and Aims

Most US states have passed medical marijuana laws (MMLs), with great variation in program regulation impacting enrollment rates. We aimed to compare changes in rates of marijuana use, heavy use and cannabis use disorder across age groups while accounting for whether states enacted medicalized (highly regulated) or non‐medical mml programs.

Design

Difference‐in‐differences estimates with time‐varying state‐level MML coded by program type (medicalized versus non‐medical). Multi‐level linear regression models adjusted for state‐level random effects and covariates as well as historical trends in use.

Setting

Nation‐wide cross‐sectional survey data from the US National Survey of Drug Use and Health (NSDUH) restricted use data portal aggregated at the state level.

Participants

Participants comprised 2004–13 NSDUH respondents (n ~ 67 500/year); age groups 12–17, 18–25 and 26+ years. States had implemented eight medicalized and 15 non‐medical MML programs.

Measurements

Primary outcome measures included (1) active (past‐month) marijuana use; (2) heavy use (> 300 days/year); and (3) cannabis use disorder diagnosis, based on DSM‐IV criteria. Covariates included program type, age group and state‐level characteristics throughout the study period.

Findings

Adults 26+ years of age living in states with non‐medical MML programs increased past‐month marijuana use 1.46% (from 4.13 to 6.59%, P = 0.01), skewing towards greater heavy marijuana by 2.36% (from 14.94 to 17.30, P = 0.09) after MMLs were enacted. However, no associated increase in the prevalence of cannabis use disorder was found during the study period. Our findings do not show increases in prevalence of marijuana use among adults in states with medicalized MML programs. Additionally, there were no increases in adolescent or young adult marijuana outcomes following MML passage, irrespective of program type.

Conclusions

Non‐medical marijuana laws enacted in US states are associated with increased marijuana use, but only among adults aged 26+ years. Researchers and policymakers should consider program regulation and subgroup characteristics (i.e. demographics) when assessing for population level outcomes. Researchers and policymakers should consider program regulation and subgroup characteristics (i.e. demographics) when assessing for population level outcomes.
Examination of cumulative effects of early adolescent depression on cannabis and alcohol use disorder in late adolescence in a community‐based cohort
Authors: Rhew Isaac C. , Fleming Charles B. , Vander Stoep Ann , Nicodimos Semret , Zheng Cheng , McCauley Elizabeth
Published: June 2017

Background and Aims

Although they often co‐occur, the longitudinal relationship between depression and substance use disorders during adolescence remains unclear. This study estimated the effects of cumulative depression during early adolescence (ages 13–15 years) on the likelihood of cannabis use disorder (CUD) and alcohol use disorder (AUD) at age 18.

Design

Prospective cohort study of youth assessed at least annually between 6th and 9th grades (~ age 12–15) and again at age 18. Marginal structural models based on a counterfactual framework that accounted for both potential fixed and time‐varying confounders were used to estimate cumulative effects of depressive symptoms over early adolescence.

Setting

The sample originated from four public middle schools in Seattle, Washington, USA.

Participants

The sample consisted of 521 youth (48.4% female; 44.5% were non‐Hispanic White).

Measurements

Structured in‐person interviews with youth and their parents were conducted to assess diagnostic symptom counts of depression during early adolescence; diagnoses of CUD and AUD at age 18 was based the Voice‐Diagnostic Interview Schedule for Children. Cumulative depression was defined as the sum of depression symptom counts from grades 7–9.

Findings

The past‐year prevalence of cannabis and alcohol use disorder at the age 18 study wave was 20.9 and 19.8%, respectively. A 1 standard deviation increase in cumulative depression during early adolescence was associated with a 50% higher likelihood of CUD [prevalence ratio (PR) = 1.50; 95% confidence interval (CI) = 1.07, 2.10]. Although similar in direction, there was no statistically significant association between depression and AUD (PR = 1.41; 95% CI = 0.94, 2.11). Further, there were no differences in associations according to gender.

Conclusions

Youth with more chronic or severe forms of depression during early adolescence may be at elevated risk for developing cannabis use disorder compared with otherwise similar youth who experience fewer depressive symptoms during early adolescence.
Endothelin‐1 receptor blockade as new possible therapeutic approach in multiple myeloma
Authors: Russignan Anna , Spina Cecilia , Tamassia Nicola , Cassaro Adriana , Rigo Antonella , Bagnato Anna , Rosanò Laura , Bonalumi Angela , Gottardi Michele , Zanatta Lucia , Giacomazzi Alice , Scupoli Maria Teresa , Tinelli Martina , Salvadori Ugo , Mosna Federico , Zamò Alberto , Cassatella Marco A. , Vinante Fabrizio , Tecchio Cristina
Published: June 2017

New effective treatments are needed to improve outcomes for multiple myeloma (MM) patients. Receptors with restricted expression on plasma cells (PCs) represent attractive new therapeutic targets. The endothelin‐1 (EDN1) axis, consisting of EDN1 acting through EDN‐receptor A (EDNRA) and B (EDNRB), was previously shown to be overexpressed in several tumours, including MM. However, there is incomplete understanding of how EDN1 axis regulates MM growth and response to therapy. Besides EDNRA, the majority of MM cell lines and primary malignant PCs express high levels of EDNRB and release EDN1. Similarly, bone‐marrow microenvironment cells also secrete EDN1. Investigating the extent of epigenetic dysregulation of EDNRB gene in MM, we found that hypermethylation of EDNRB promoter and subsequent down‐regulation of EDNRB gene was observed in PCs or B lymphocytes from healthy donors compared to EDNRB‐expressing malignant PCs. Pharmacological blockade with the dual EDN1 receptor antagonist bosentan decreased cell viability and MAPK activation of U266 and RPMI‐8226 cells. Interestingly, the combination of bosentan and the proteasome inhibitor bortezomib, currently approved for MM treatment, resulted in synergistic cytotoxic effects. Overall, our data has uncovered EDN1‐mediated autocrine and paracrine mechanisms that regulate malignant PCs growth and drug response, and support EDN1 receptors as new therapeutic targets in MM.
The fifth subunit of the (α4β2)2β2 nicotinic ACh receptor modulates maximal ACh responses
Authors: New Karina , Del Villar Silvia Garcia , Mazzaferro Simone , Alcaino Constanza , Bermudez Isabel
Published: June 2017

Background and Purpose

The fifth subunit in the (α4β2)2α4 nicotinic ACh receptor (nAChR) plays a determining role in the pharmacology of this nAChR type. Here, we have examined the role of the fifth subunit in the ACh responses of the (α4β2)2β2 nAChR type.

Experimental Approach

The role of the fifth subunit in receptor function was explored using two‐electrode voltage clamp electrophysiology, along with subunit‐targeted mutagenesis and the substituted cysteine scanning method applied to fully linked (α4β2)2β2 receptors.

Key Results

Covalent modification of the cysteine‐substituted fifth subunit with a thiol‐reactive agent (MTS) caused irreversible inhibition of receptor function. ACh reduced the rate of the reaction to MTS, but the competitive inhibitor dihydro‐β‐erythroidine had no effect. Alanine substitution of conserved residues that line the core of the agonist sites on α4(+)/β2(−) interfaces did not impair receptor function. However, impairment of agonist binding to α4(+)/β2(−) agonist sites by mutagenesis modified the effect of ACh on the rate of the reaction to MTS. The extent of this effect was dependent on the position of the agonist site relative to the fifth subunit.

Conclusions and Implications

The fifth subunit in the (α4β2)2β2 receptor isoform modulates maximal ACh responses. This effect appears to be driven by a modulatory, and asymmetric, association with the α4(+)/β2(−) agonist sites.

Linked Articles

This article is part of a themed section on Nicotinic Acetylcholine Receptors. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.11/issuetoc