bluuebunny/crossref_metadata_2025 huggingface dataset:
Meister der Selbstverteidigung
Authors: Tetsch Larissa
Published: January 2018

Der Stich des Mandschurei‐Skorpions löst an der Einstichstelle starke Schmerzen aus und setzt so dessen Feinde schachmatt. Die Schmerzen erzeugt ein Peptidtoxin, das an einen Schmerzrezeptor bindet und dabei synergistisch mit Protonen aus dem sauren Giftcocktail wirkt. Auf diese Weise wird der Schmerzrezeptor so stark aktiviert, wie es sonst nur durch eine extreme Ansäuerung des Gewebes zu erreichen wäre.
Nonsurgical premature menopause and reproductive implications in survivors of childhood cancer: A report from the Childhood Cancer Survivor Study
Authors: Levine Jennifer M , Whitton John A. , Ginsberg Jill P. , Green Daniel M. , Leisenring Wendy M. , Stovall Marilyn , Robison Leslie L. , Armstrong Gregory T. , Sklar Charles A.
Published: January 2018

BACKGROUND

Survivors of childhood cancer are at risk of nonsurgical premature menopause (NSPM). To the authors' knowledge, risk factors for NSPM and its impact on reproduction remain poorly defined.

METHODS

The menopausal status of 2930 survivors diagnosed between 1970 and 1986 (median age, 6 years [range, birth‐20 years]) who were aged > 18 years at the time of the current study (median age, 35 years [range, 18‐58 years]) was compared with 1399 siblings. NSPM was defined as the cessation of menses ≥6 months in duration occurring 5 years after diagnosis and before age 40 that was not due to pregnancy, surgery, or medications. Among survivors, multivariable logistic regression identified risk factors for NSPM. Pregnancy and live birth rates were compared between survivors with and without NSPM.

RESULTS

A total of 110 survivors developed NSPM (median age, 32 years [range, 16‐40 years]), with a prevalence at age 40 years of 9.1% (95% confidence interval [95% CI], 4.9%‐17.2%); the odds ratio (OR) was 10.5 (95% CI, 4.2‐26.3) compared with siblings. Independent risk factors included exposure to a procarbazine dose ≥4000 mg/m2 (OR, 8.96 [95% CI, 5.02‐16.00]), any dose of ovarian radiation (OvRT) (OvRT < 500 cGy: OR, 2.73 [95% CI, 1.33‐5.61] and OvRT ≥ 500 cGy: OR, 8.02 [95% CI, 2.81‐22.85]; referent RT, 0), and receipt of a stem cell transplantation (OR, 6.35; 95% CI, 1.19‐33.93). Compared with survivors without NSPM, those who developed NSPM were less likely to ever be pregnant (rate ratio, 0.49; 95% CI, 0.27‐0.80) or to have a live birth (rate ratio, 0.42; 95% CI, 0.19‐0.79) between ages 31 and 40 years.

CONCLUSIONS

Survivors of childhood cancer are at risk of NSPM associated with lower rates of live birth in their 30s. Those at risk should consider fertility preservation if they anticipate delaying childbearing. Cancer 2018;124:1044‐52. © 2018 American Cancer Society.
Bladder cancer and the National Cancer Data Base: New insight or misinformation?
Authors: Choudhury Ananya , Hoskin Peter J.
Published: January 2018

In the absence of randomized clinical trials, big data base sets can provide insights into patient management. However, it is important to be aware of the weaknesses of each data base so appropriate conclusions can be drawn. Overinterpretation must be avoided.
Racial/ethnic differences in thyroid cancer incidence in the United States, 2007‐2014
Authors: Weeks Kristin S. , Kahl Amanda R. , Lynch Charles F. , Charlton Mary E.
Published: January 2018

BACKGROUND

Small tumor diagnostic tools including ultrasound‐guided fine needle aspiration (FNA) and computed tomography (CT) could be causing rising and racially/ethnically different thyroid cancer incidence rates due to variable overdiagnosis of indolent tumors. Papillary tumors and <40 mm tumors are most likely to be overdiagnosed as indolent tumors by FNA and CT.

METHODS

Age‐adjusted incidence rates (AAIRs) for the years 2007‐2014 were calculated for race/ethnicity (white, Hispanic, Asian, African American, Native American) by patient/tumor characteristics for microscopically confirmed malignant thyroid cancer cases in the Surveillance, Epidemiology, and End Results Program 18 database (SEER 18; N = 93,607). Multivariate analysis determined cancer patients' odds ratios of diagnosis with papillary thyroid carcinoma (vs other histologies) and tumors <40 mm (vs ≥40 mm).

RESULTS

For both males and females, there were statistically significant differences in incidence rates between race/ethnicity, with whites having the highest AAIRs and African Americans the lowest AAIRs. Among thyroid cancer patients, tumor size and histology differed significantly by race and insurance coverage after controlling for age, sex, stage, and tumor sequence. Non‐whites with thyroid cancer (vs whites) were less associated with small tumors (odds ratio [OR], 0.51‐0.79; P < .0001). Medicaid and uninsured patients with thyroid cancer were less associated with tumors <40 mm (OR, 0.55‐0.71; 95% confidence interval [CI], 0.49‐0.76) and papillary carcinoma (OR, 0.86; 95% CI, 0.80‐0.93).

CONCLUSION

The diagnosis of small tumors is occurring at greater rates in whites (vs non‐whites) and insured (vs Medicaid and uninsured) patients; consequently, these groups may be vulnerable to unnecessary tests and treatments or potentially aided by early detection. Guidelines that define postdetection interventions may be needed to limit the overtreatment of indolent and small papillary carcinomas. Cancer 2018;124:1483‐91. © 2018 American Cancer Society.
Cardiometabolic risk factors and survival after breast cancer in the Women's Health Initiative
Authors: Simon Michael S. , Beebe‐Dimmer Jennifer L. , Hastert Theresa A. , Manson JoAnn E. , Cespedes Feliciano Elizabeth M. , Neuhouser Marian L. , Ho Gloria Y. F. , Freudenheim Jo L. , Strickler Howard , Ruterbusch Julie , Barac Ana , Chlebowski Rowan , Caan Bette
Published: January 2018

BACKGROUND

Few studies have examined the relationship between cardiometabolic risk factors linked to metabolic syndrome and mortality among women with breast cancer.

METHODS

We used the Women's Health Initiative to evaluate the relationship between cardiometabolic risk factors, including waist circumference (WC), blood pressure, cholesterol level, and presence of type 2 diabetes, and their relation with death from breast cancer, cardiovascular disease (CVD), and other causes among 8641 women with local or regional stage invasive breast cancer. Cox proportional hazards models were used to estimate hazard ratios, and 95% confidence intervals, adjusted for important predictors of survival.

RESULTS

After a median of 11.3 years, there were 2181 total deaths, 619 (28.4%) of which were due to breast cancer. Most participants (55.7%) had at least 2 cardiometabolic risk factors, and 4.9% had 3 or 4. Having a larger number of risk factors was associated with higher risk of CVD and other‐cause mortality (P trend < .001 for both), but not with breast cancer mortality (P trend = .86). Increased WC was associated with a higher risk of CVD (hazard ratio [HR], 1.28; 95% confidence interval [CI], 1.05‐1.57) and other‐cause mortality (HR, 1.32; 95% CI, 1.16‐1.49) and only with a small and nonsignificant higher risk of breast cancer mortality (HR, 1.19; 95% CI, 0.93‐1.52). The results did not differ in analyses stratified by race, hormone receptor status, or after an analysis of cases diagnosed within 5 years after baseline.

CONCLUSIONS

Among women with early stage breast cancer, cardiometabolic risk factors are significantly associated with cardiovascular and other‐cause mortality, but not breast cancer mortality. Cancer 2018;124:1798‐807. © 2018 American Cancer Society
Transfection by Electroporation
Authors: Potter Huntington , Heller Richard
Published: January 2018

Electroporation—the use of high‐voltage electric shocks to introduce DNA into cells—can be used with most cell types, yields a high frequency of both stable transformation and transient gene expression, and, because it requires fewer steps, can be easier than alternate techniques. This unit describes electroporation of mammalian cells, including ES cells for the preparation of knock‐out, knock‐in, and transgenic mice. Protocols are described for the use of electroporation in vivo to perform gene therapy for cancer therapy and DNA vaccination. Also described are modifications for preparation and transfection of plant protoplasts. © 2018 by John Wiley & Sons, Inc.
Avian Retrovirus‐Mediated Tumor‐Specific Gene Knockout
Authors: Wang Wei , Dong Bingning , Yang Feng
Published: January 2018

The RCAS (replication‐competent avian sarcoma leukosis virus long‐terminal repeat with splice acceptor)‐TVA (tumor virus A) gene delivery system has been successfully used in modeling human cancers. Based on this, we have recently developed a novel RCI‐Oncogene (RCAS‐Cre‐IRES‐Oncogene) gene delivery system that can be used to efficiently manipulate gene expression in spontaneous tumors in vivo. We used this system for tumor gene knockout (TuKO) and demonstrated a crucial role of FGFR1 in driving mammary tumor metastasis. This versatile tumor gene modification system can also be adapted into different configurations to address different questions in appropriate mutant mouse hosts. Here we describe a protocol using the TuKO approach to knock out a gene of interest in tumors in appropriate hosts. © 2018 by John Wiley & Sons, Inc.
Effects of Rare Earth Elements and Nitrogen Co‐Doped on the Photocatalytic Performance of TiO2
Authors: Bao Ruiyu , Yu Yanmin , Chen Huiying , Wang Wenzhong , Xia Jianxin , Li Hua
Published: January 2018

Titanium dioxide (TiO2), which is codoped with nine different rare earth mental ions (RE3+ = lanthanum (La3+), cerium (Ce3+), praseodymium (Pr3+), neodymium (Nd3+), samarium (Sm3+), gadolinium (Gd3+), erbium (Er3+), ytterbium (Yb3+), lutetium (Lu3+)) and nitrogen (N), are synthesized by non‐hydrolytic sol‐gel method under different calcination temperatures. The morphology, structure and performance of as‐prepared samples are characterized by X‐ray diffraction (XRD), scanning electron microscope (SEM), X‐ray photoelectron spectroscopy (XPS), UV‐vis diffuse reflectance spectroscopy (DRS) and ultraviolet‐visible absorption spectroscopy. The results indicat that co‐doping can inhibit the particles growth significantly and extend light‐absorption to the visible region. Nd/N and Pr/N co‐doped TiO2 (calcining temperature at 380 °C) exhibit superior photocatalytic activity toward methyl orange (MO) degradation under visible light irradiation for 150 min, the degradation rate of MO solution are approximately 91 and 89% respectively. By comparison, the degradation rate are only 43 and 7% for the N‐TiO2 and pure TiO2 respectively.
Sustainable Synthesis of Oxalic and Succinic Acid through Aerobic Oxidation of C6 Polyols Under Mild Conditions
Authors: Ventura Maria , Williamson David , Lobefaro Francesco , Jones Matthew D. , Mattia Davide , Nocito Francesco , Aresta Michele , Dibenedetto Angela
Published: January 2018

The sustainable chemical industry encompasses a shift from the use of fossil carbon to renewable carbon. The synthesis of chemicals from nonedible biomass (cellulosic or oil) represents one of the key steps for “greening” the chemical industry. In this paper, we report the aerobic oxidative cleavage of C6 polyols (5‐HMF, glucose, fructose and sucrose) to oxalic acid (OA) and succinic acid (SA) in water under mild conditions using M@CNT and M@NCNT (M=Fe, V; CNT=carbon nanotubes; NCNT=N‐doped CNT), which, under suitable conditions, were recoverable and reusable without any loss of efficiency. The influence of the temperature, O2 pressure (P
), reaction time and stirring rate are discussed and the best reaction conditions are determined for an almost complete conversion of the starting material and a good OA yield of 48 %. SA and formic acid were the only co‐products. The former could be further converted into OA by oxidation in the presence of formic acid, resulting in an overall OA yield of >62 %. This process was clean and did not produce organic waste nor gas emissions.
Analysis of D2D‐pairing scheme based on Voronoi diagram in cellular networks
Authors: Liu Chun‐Peng , He Chen‐Guang , Meng Wei‐Xiao
Published: January 2018

This paper presents a device‐to‐device (D2D)–pairing scheme based on Voronoi diagram, which establishes D2D links by the relation of transmission powers and link distances. Using the principle of stochastic geometry and channel inversion, the coverage probability is analyzed, we observe that the co‐channel interference caused by cellular networks is stable in theory, and the influence of link distance parameter is highlighted as well. According to the second‐order moment of link distance, the new metric space of D2D terminals set is constructed, in which Voronoi diagram is degenerated into Delaunay triangles set to represent the potential D2D links. In addition, on the basis of the mini‐max length criterion of Delaunay triangle, the D2D communication range–limiting algorithm is designed. Finally, the more intuitive results compared with conventional D2D communications are displayed by simulations. Owing to restraining the D2D communication range, lower co‐channel interference can be obtained. Specially, the D2D‐pairing scheme is approximate local optimal under the D2D communication range–limiting algorithm, and it can provide more fairness than greedy algorithm.
Book Review
Authors: Dee Jay R. , Vallie R. Arlene , Vang Mai Hu
Published: January 2018

A Guide for Leaders in Higher Education: Core Concepts, Competencies, and Tools
Infrared heater system for warming tropical forest understory plants and soils
Authors: Kimball Bruce A. , Alonso‐Rodríguez Aura M. , Cavaleri Molly A. , Reed Sasha C. , González Grizelle , Wood Tana E.
Published: January 2018

The response of tropical forests to global warming is one of the largest uncertainties in predicting the future carbon balance of Earth. To determine the likely effects of elevated temperatures on tropical forest understory plants and soils, as well as other ecosystems, an infrared (IR) heater system was developed to provide in situ warming for the Tropical Responses to Altered Climate Experiment (TRACE) in the Luquillo Experimental Forest in Puerto Rico. Three replicate heated 4‐m‐diameter plots were warmed to maintain a 4°C increase in understory vegetation compared to three unheated control plots, as sensed by IR thermometers. The equipment was larger than any used previously and was subjected to challenges different from those of many temperate ecosystem warming systems, including frequent power surges and outages, high humidity, heavy rains, hurricanes, saturated clayey soils, and steep slopes. The system was able to maintain the target 4.0°C increase in hourly average vegetation temperatures to within ± 0.1°C. The vegetation was heterogeneous and on a 21° slope, which decreased uniformity of the warming treatment on the plots; yet, the green leaves were fairly uniformly warmed, and there was little difference among 0–10 cm depth soil temperatures at the plot centers, edges, and midway between. Soil temperatures at the 40–50 cm depth increased about 3°C compared to the controls after a month of warming. As expected, the soil in the heated plots dried faster than that of the control plots, but the average soil moisture remained adequate for the plants. The TRACE heating system produced an adequately uniform warming precisely controlled down to at least 50‐cm soil depth, thereby creating a treatment that allows for assessing mechanistic responses of tropical plants and soil to warming, with applicability to other ecosystems. No physical obstacles to scaling the approach to taller vegetation (i.e., trees) and larger plots were observed.
You stay, but I Hop: Host shifting near and far co‐dominated the evolution of Enchenopa treehoppers
Authors: Hsu Yu‐Hsun , Cocroft Reginald B. , Snyder Robert L. , Lin Chung‐Ping
Published: January 2018

The importance and prevalence of phylogenetic tracking between hosts and dependent organisms caused by co‐evolution and shifting between closely related host species have been debated for decades. Most studies of phylogenetic tracking among phytophagous insects and their host plants have been limited to insects feeding on a narrow range of host species. However, narrow host ranges can confound phylogenetic tracking (phylogenetic tracking hypothesis) with host shifting between hosts of intermediate relationship (intermediate hypothesis). Here, we investigated the evolutionary history of the Enchenopa binotata complex of treehoppers. Each species in this complex has high host fidelity, but the entire complex uses hosts across eight plant orders. The phylogenies of E. binotata were reconstructed to evaluate whether (1) tracking host phylogeny; or (2) shifting between intermediately related host plants better explains the evolutionary history of E. binotata. Our results suggest that E. binotata primarily shifted between both distant and intermediate host plants regardless of host phylogeny and less frequently tracked the phylogeny of their hosts. These findings indicate that phytophagous insects with high host fidelity, such as E. binotata, are capable of adaptation not only to closely related host plants but also to novel hosts, likely with diverse phenology and defense mechanisms.
Species co‐occurrence networks: Can they reveal trophic and non‐trophic interactions in ecological communities?
Authors: Freilich Mara A. , Wieters Evie , Broitman Bernardo R. , Marquet Pablo A. , Navarrete Sergio A.
Published: January 2018

Co‐occurrence methods are increasingly utilized in ecology to infer networks of species interactions where detailed knowledge based on empirical studies is difficult to obtain. Their use is particularly common, but not restricted to, microbial networks constructed from metagenomic analyses. In this study, we test the efficacy of this procedure by comparing an inferred network constructed using spatially intensive co‐occurrence data from the rocky intertidal zone in central Chile to a well‐resolved, empirically based, species interaction network from the same region. We evaluated the overlap in the information provided by each network and the extent to which there is a bias for co‐occurrence data to better detect known trophic or non‐trophic, positive or negative interactions. We found a poor correspondence between the co‐occurrence network and the known species interactions with overall sensitivity (probability of true link detection) equal to 0.469, and specificity (true non‐interaction) equal to 0.527. The ability to detect interactions varied with interaction type. Positive non‐trophic interactions such as commensalism and facilitation were detected at the highest rates. These results demonstrate that co‐occurrence networks do not represent classical ecological networks in which interactions are defined by direct observations or experimental manipulations. Co‐occurrence networks provide information about the joint spatial effects of environmental conditions, recruitment, and, to some extent, biotic interactions, and among the latter, they tend to better detect niche‐expanding positive non‐trophic interactions. Detection of links (sensitivity or specificity) was not higher for well‐known intertidal keystone species than for the rest of consumers in the community. Thus, as observed in previous empirical and theoretical studies, patterns of interactions in co‐occurrence networks must be interpreted with caution, especially when extending interaction‐based ecological theory to interpret network variability and stability. Co‐occurrence networks may be particularly valuable for analysis of community dynamics that blends interactions and environment, rather than pairwise interactions alone.
The aryl hydrocarbon receptor modulates the function of human CD56bright NK cells
Authors: Moreno‐Nieves Uriel Y. , Mundy David C. , Shin June Ho , Tam Kenric , Sunwoo John B.
Published: January 2018

Human natural killer (NK) cells are divided into two subsets: CD56bright and CD56dim NK cells, which differ in maturation, function and distribution. Mechanisms regulating NK cell functions are not completely understood. Aryl hydrocarbon receptor (AhR) is a ligand‐activated transcription factor, that binds to a variety of endogenous and exogenous molecules, and that has recently been shown to modulate the function and differentiation of immune cells. Here, we studied the expression of AhR and its involvement in the regulation of NK cell functions. We found that AhR mRNA is highly expressed in peripheral CD56bright NK cells and that AhR mRNA expression gradually decreases as NK cells display a more mature phenotype. CD56bright NK cells were highly sensitive to AhR ligands. Specifically, AhR ligands modulated their activation and their expression of NK cell receptors, as well as cytokine secretion which is the major function of these cells. As CD56bright NK cells are highly enriched in tissues and in tumors, our observations point to a possible effect of local AhR ligands in the regulation of the function of CD56bright tissue‐resident or intratumoral NK cells.
Synthesis, Crystal and Electronic Structure of the Titanium Bismuthides Sr5Ti12Bi19+x, Ba5Ti12Bi19+x, and Sr5–δEuδTi12Bi19+x (x ≈ 0.5–1.0; δ ≈ 2.4, 4.0)
Authors: Ovchinnikov Alexander , Bobev Svilen
Published: January 2018

Crystals of the new ternary bismuthides AE5Ti12Bi19+x (AE = Sr, Ba) and Sr5–δEuδTi12Bi19+x (δ ≈ 2.4, 4.0; x ≤ 1.0) were grown using an excess of molten Bi as a flux. The title compounds crystallize in the cubic non‐centrosymmetric space group P43m and are structurally related to the antimonides Ba5M12Sb19+x (M = Ti, V, Nb). The crystal structure features Ti atoms stuffed in the γ‐brass‐like sub‐lattice made of AE (AE = Sr, Ba, Eu) and Bi atoms. The arrangement of the AE atoms, on its own, represents a framework consisting of interconnected regular tetrahedra and octahedra. Another notable attribute of the AE5Ti12Bi19+x structure is the disordered Bi moiety located at the center of the unit cell and showing homoatomic Bi–Bi bonding. Electronic structure calculations and electrical resistivity measurements indicate metallic behavior of the new bismuthides. Magnetization measurements on samples of Sr5–δEuδTi12Bi19+x show paramagnetic behavior consistent with the 2+ ground state for Eu. The measurements also confirm no magnetic ordering down to 3 K, stemming from the geometrically frustrated exchange interactions of the Eu2+ cations.
Cattle grazing and fish recovery on US federal lands: can social–ecological systems science help?
Authors: Charnley Susan , Gosnell Hannah , Wendel Kendra L , Rowland Mary M , Wisdom Michael J
Published: January 2018

In the western US, grazing management on federal lands containing habitat for fish species listed under the US Endangered Species Act (ESA) has sparked social conflict and litigation for decades. To date, the problem has been addressed through a top‐down environmental governance system, but rangeland managers and grazing permittees now believe there is a need for more innovative management strategies. This article explores how social–ecological systems (SES) science can address rangeland management challenges associated with the survival and recovery of ESA‐listed fish species on federal lands where cattle grazing is a dominant type of land use. We focus on the Blue Mountains of eastern Oregon, where the Mountain Social Ecological Observatory Network's Blue Mountains Working Group is collaborating with diverse stakeholders to develop and test a novel grazing system designed to reduce the impact of cattle on riparian areas using an SES science approach. Although not a complete solution, SES science holds promise for improving rangeland management.
Principal component analysis of physicochemical and sensory characteristics of beef rounds extended with gum arabic from Acacia senegal var. kerensis
Authors: Mwove Johnson K. , Gogo Lilian A. , Chikamai Ben N. , Omwamba Mary , Mahungu Symon M.
Published: January 2018

Principal component analysis (PCA) was carried out to study the relationship between 24 meat quality measurements taken from beef round samples that were injected with curing brines containing gum arabic (1%, 1.5%, 2%, 2.5%, and 3%) and soy protein concentrate (SPC) (3.5%) at two injection levels (30% and 35%). The measurements used to describe beef round quality were expressible moisture, moisture content, cook yield, possible injection, achieved gum arabic level in beef round, and protein content, as well as descriptive sensory attributes for flavor, texture, basic tastes, feeling factors, color, and overall acceptability. Several significant correlations were found between beef round quality parameters. The highest significant negative and positive correlations were recorded between color intensity and gray color and between color intensity and brown color, respectively. The first seven principal components (PCs) were extracted explaining over 95% of the total variance. The first PC was characterized by texture attributes (hardness and denseness), feeling factors (chemical taste and chemical burn), and two physicochemical properties (expressible moisture and achieved gum arabic level). Taste attribute (saltiness), physicochemical attributes (cook yield and possible injection), and overall acceptability were useful in defining the second PC, while the third PC was characterized by metallic taste, gray color, brown color, and physicochemical attributes (moisture and protein content). The correlation loading plot showed that the distribution of the samples on the axes of the first two PCs allowed for differentiation of samples injected to 30% injection level which were placed on the upper side of the biplot from those injected to 35% which were placed on the lower side. Similarly, beef samples extended with gum arabic and those containing SPC were also visible when scores for the first and third PCs were plotted. Thus, PCA was efficient in analyzing the quality characteristics of beef rounds extended with gum arabic.
EPA Making 2018 Air Permit Modeling Even More Uncertain
Authors: Hoffnagle Gale F.
Published: January 2018

On January 17, 2017, the US Environmental Protection Agency (EPA) finalized changes to the Guideline on Air Quality Models that will make it much more difficult to obtain such a permit.
Certification of US Gas Pipelines: Assault on a “Modern Miracle”?
Authors: Makholm Jeff D.
Published: January 2018

It is no overstatement to say that the manner in which the Federal Energy Regulatory Commission (FERC) regulates the US interstate natural gas industry is a Stradivarius of both regulatory effectiveness and restraint. With a staff of about 280 and an annual budget of around $62 million (2016), the FERC gas division deals with certificate entry and pricing for about 70 percent of the world's major gas pipelines. This amount is a tiny expense for the linchpin of the competitive US gas market (by comparison, it is about one‐twentieth of the cost of the independent system operators that regulate the US electricity transmission systems in those states with wholesale power markets).
Cenozoic uplift of the Qimantage Mountains, northeastern Tibet: Contraints from provenance analysis of Cenozoic sediments in Qaidam Basin
Authors: Zhou Hai , Chen Liang , Diwu Chunrong , Lei Chuan
Published: January 2018

Qimantage Orogen as the western part of East Kunlun Mountains is located in the northeastern margin of the Tibet Plateau. In this contribution, detrital zircon age spectra combined with heavy mineral analysis of Cenozoic sediments from Qaidam Basin were applied to reveal the uplift history of Qimantage Mountains. Our results show that the Cenozoic staged uplift of the Qimantage Mountains exhibit eastward and northward uplift characteristics. From the middle Eocene to Quaternary, there are three major uplift stages for Qimantage Mountains: the first stage is from middle Eocene to late Eocene (~45–35.3 Ma). The range developed a topographic pattern of east‐high and west‐low at that time, and the uplift of the east part range at that time is significant perhaps linked to the Cenozoic uplift of Tibetan Plateau due to its significant crustal shortening. The second stage is from early Oligocene to late Miocene (~15–8 Ma). During this stage, the uplift is both significant in tectonic and topographic aspects, and the overall uplift occurred mainly in the middle and west part of Qimantage Mountains. The last stage is from late Miocene to Quaternary (~2.8 Ma to present), and the Qimantage Mountains experienced complete uplift. The provenance is mainly the northern Qimantage Mountains without sediments supplied from further south, and therefore, the Qaidam Basin became an intermontane basin geomorphically.
Combined effects of the subductions of the Pacific Plate and Indian Plate in Central China in the Cenozoic: Recorded from the Wei River Basin
Authors: Fan Shuang‐Hu , Chen Shu‐E , Li Rongxi
Published: January 2018

The Wei River Basin is located between the Qinling Orogenic Belt and the Ordos Block. It is an important seismic belt and part of the Silk Road in China. The development of the basin is the result of interaction between the Qinling Orogenic Belt and the Ordos Block. Based on the geomorphic features, sedimentary characteristics, and geophysical detection data, combined with the tectonic movement of the Qinling Orogenic Belt in the Cenozoic, this article considers that the Wei River Basin was formed by both the Qinling Orogenic Belt thrusting to the Ordos Block and the left‐lateral strike‐slipping of the margin fault in the Cenozoic. The combined actions of Indian Plate subduction and Pacific Plate subduction have caused the eastern section of the Wei River Basin to turn from east–west to northeast and the Ordos Block to undergo counterclockwise rotation. The analysis of the formation mechanism and evolutionary process of the Wei River Basin should be of great practical significance in the study of the seismicity of the Wei River Basin.
Components and structures of the eastern Tethyan Himalayan Sequence in SW China: Not a passive margin shelf but a mélange accretionary prism
Authors: Ao Songjian , Xiao Wenjiao , Windley Brian F. , Zhang Ji'en , Zhang Zhiyong , Yang Lei
Published: January 2018

The Tethyan Himalaya Sequence between the Yarlung‐Zangbo Suture and South Tibetan Detachment is a fundamental component of the Himalayan orogenic belt, traditionally considered to belong to the passive continental margin of India. However, the eastern Tethyan Himalaya Sequence is poorly understood, compared with that in the central and western Himalaya. To improve general understanding, we undertook north‐south geological‐structural profiles across all the litho‐tectonic units of the eastern Tethyan Himalaya Sequence and produced new isotopic‐geochemical data from all units, to constrain their mode of occurrence, structure, tectonic setting, and time of formation. The whole Tethyan Himalaya Sequence consists of a thrust‐imbricated mélange that contains blocks of ophiolites (such as Lang County, Yumen, and Lhunze), oceanic islands (e.g., Comei) with ocean island basalts‐type basalts, mafic greenschists, limestone olistoliths, and cherts in a turbiditic matrix of greywackes, siltstones, and slates in south‐directed thrust slices. Our findings suggest that the eastern Tethyan Himalaya Sequence represents the evolution of an accretionary prism, rather than a passive margin of the Indian Plate. The prism was created during northward subduction of Neo‐Tethys between ~130 and ~50 Ma. These data allow us to produce a new tectonic model for the structural development of the eastern Himalayan orogenic belt in relation to the India‐Asia collision.
Petrology and mineralogy of pumice from the Iheya North Knoll, Okinawa Trough: Implications for the differentiation of crystal‐poor and volatile‐rich melts in the magma chamber
Authors: Zhang Yuxiang , Zeng Zhigang , Yin Xuebo , Qi Haiyan , Chen Shuai , Wang Xiaoyuan , Shu Yunchao , Chen Zuxing
Published: January 2018

The Iheya North Knoll is a submarine hill that is covered with pumice in the Okinawa Trough. The petrology and mineralogy of the crystal‐poor rhyolitic pumice collected from two sampling sites (T3 and T6) on the knoll were analysed in this article. The T6 pumice, which contains some mafic minerals (e.g., clinopyroxene, orthopyroxene), is slightly more crystal‐rich (<5 vol.%) than the T3 pumice (<2 vol.%). However, both types of pumice are high‐potassium rhyolites with similar Nd isotopic ratios and rare earth element patterns, as well as similar glass compositions, which indicates that they may fall along a line of descent of comagmatic evolution. The T6 pumice contains some xenomorphic clinopyroxenes that are not in equilibrium with their whole‐rock composition, which suggests that the crystal‐poor melt was extracted from a more mafic source. The T3 pumice features a flow structure, and its matrix glass records higher Cl concentrations and a lower total mass than the T6 pumice, which implies that the T3 melt has a higher volatile content and lower viscosity. The distinct petrographic characteristics but similar matrix glass compositions of the T3 and T6 pumice suggest that the extracted melt was physically differentiated during ascent, with the more crystal‐poor and volatile‐rich T3 melt reaching a higher lever in the magma chamber. Meanwhile, simulation calculations indicate that the melt experienced near‐adiabatic decompression‐driven chemical differentiation, which led to the growth of sodium‐rich plagioclase but not quartz in the pumice.
Sequence architecture and depositional evolution in Lufeng Depression, Pearl River Mouth Basin, South China Sea Part A: The braided delta deposits of Cenozoic Enping Formation
Authors: Xia Shiqiang , Liu Zhen , Luo Donghong , Shu Liangfeng , Zhang Zhenguo , Gao Lianfeng , Dong Guiyu , Zhang Linting , Leng Chunpeng , Zhang Bingkun
Published: January 2018

The seismic merging dataset, wireline logs, core photographs, thin sections, and other geological information were employed to investigate sequence architecture and reveal depositional evolution of Enping Formation in Lufeng Depression, Pearl River Mouth Basin. The results showed that one second‐order sequence and four third‐order sequences were identified based on the unconformities along basin margin/slope and correlative conformities in the basin centre. In addition, several associated sedimentary facies or microfacies (including braided channel deposits, subaqueous distributary channel deposits, beach‐bar deposits, and so on) that were recognized within sequence stratigraphic framework and depositional evolution were revealed by well tie–seismic correlations with seismic attributes extracted from the stratal slicing in terms of sand sections/units in Enping Formation. It was characterized by progradational process from seismic attributes in general that the delta deposits gradually retrograded. Through comprehensive analysis, it can be concluded that episodic tectonic movements and subsequent uplift played an important role in controlling sequence architecture. Sediment supply and lacustrine level fluctuations derived from accommodation space changes exerted an essential effect on depositional evolution. This study provides new and robust insights into understanding the sequence architecture, depositional evolution, and hydrocarbon exploration in Enping Formation. In addition to the significance for academia, study of sequence architecture and depositional evolution are of great importance for hosting potential hydrocarbon reserves, because they are frequently related to important and potential reservoirs. Consequently, investigating sequence architecture and depositional evolution are significant economically as well.
Provenance discrimination between Atasta and Alvarado beach sands, western Gulf of Mexico, Mexico: Constraints from detrital zircon chemistry and U–Pb geochronology
Authors: Armstrong‐Altrin John S. , Ramos‐Vázquez Mayla A. , Zavala‐León Ana C. , Montiel‐García Patricia C.
Published: January 2018

The bulk sand samples and detrital zircons collected from the Atasta and Alvarado beach areas in the southwestern Gulf of Mexico have been analysed for geochemistry and U–Pb ages to constrain their provenance. The index of chemical maturity and SiO2/Al2O3 ratio of the Atasta and Alvarado beach sands indicated low compositional maturity. The chondrite‐normalized REE patterns and Eu anomalies of the Atasta and Alvarado beach sands suggested that the sands were derived from felsic and intermediate igneous rock types, respectively. A wide range in Th and U contents of the Atasta (~1.0–884 ppm and ~39–883 ppm, respectively) and Alvarado (~13–2,641 ppm and ~21–2,457 ppm, respectively) zircons likely indicates that the detrital zircon populations consist of zircons derived from multiple sources. The total rare earth element (ΣREE) content in the Atasta and Alvarado zircons ranges from ~151 to 2,088 ppm and ~154 to 3,580 ppm, respectively. The chondrite‐normalized REE patterns of zircons from the two beach areas show slightly depleted light REE (LREE) and enriched heavy REE (HREE), as well as positive Ce and negative Eu anomalies. A few zircons of Alvarado beach lack a Ce positive anomaly but exhibit a distinct Eu anomaly. The differences in REE patterns among zircons between the two beach areas revealed the variations in the type of source terranes, which supplied zircons to the beach areas. The detrital zircon age distribution for the Atasta beach is homogeneous, showing a prominent Proterozoic peak (~596–2,461 Ma; number of samples n = 62) with few Cenozoic (~10.43–65.2 Ma; n = 4) and Palaeozoic (~380–468 Ma; n = 5) zircons. The zircon U–Pb ages of Alvarado beach revealed Cenozoic (~0.25–63.9 Ma; n = 65), Mesozoic (~67.9–181.2 Ma), Palaeozoic (~252–297 Ma), and Proterozoic (~589–1,501 Ma) age clusters with predominant Cenozoic zircons. The comparison of zircon REE chemistry and geochronological data of this study with published data suggests that the source terranes, which supplied zircons to the Atasta beach, were the Chiapas Massif and Oaxacan complexes, whereas the zircons in the Alvarado beach were derived from the nearby Mexican Volcanic Belt and Eastern Alkaline Province. The provenance variation between the two beach areas was also revealed by the dissimilarities in zircon age clusters.
Geological characteristics, metallogenesis, and tectonic setting of porphyry–skarn Cu deposits in East Kunlun Orogen
Authors: Wang Hui , Feng Chengyou , Li Rongxi , Li Daxin
Published: January 2018

The East Kunlun Orogen (EKO), as the west segment of the Central China Orogen, is the most important Triassic polymetallic metallogenic belt in China. In this paper, we summarize the geological characteristics (stratigraphy, structure, ore‐related plutons, wall rock alteration, and orebodies), ore‐forming fluids and materials, geochronology, and petro‐geochemistry of the representative porphyry–skarn Cu–polymetallic deposits, including the Saishitang, Hutouya, and Kaerqueka deposits in the EKO. The porphyry–skarn Cu deposits in the EKO are mainly distributed in tectonic units of the Qimantagh Belt and the Elashan Belt. Among them, the skarn Cu deposits provide the majority of Cu resources, which mainly occur in the contact zone between the Triassic granitoids and the volcanic–sedimentary rocks (e.g., the Ordovician–Silurian Tanjianshan Group and the Early to Middle Triassic Hongshuichuan Group), and the skarn and orebodies are mainly controlled by interlayer–gliding structures. Ore‐forming fluids of the porphyry Cu deposits are magmatic mixed with meteoric water, whereas the fluids of skarn Cu deposits are mainly of magmatic origin. The higher δ18O (>10‰) of garnet and pyroxene in prograde skarn and wide range of sulphur isotopic compositions (δ34S values from −8.9‰ to 11.0‰) suggest that ore‐forming materials of skarn Cu deposits were partially derived from the country rocks. Based on detailed field investigations, we identified four Cu mineralization types, including veinlet–disseminated Cu (Mo, Au) mineralization occurring within the intrusions, proximal skarn Cu (Fe, Pb, Zn, Au) mineralization, distal skarn Cu mineralization, and distal skarn Pb–Zn (Cu) mineralization. The porphyry–skarn Cu deposits are associated with magmatism that occurred mainly during 235–218 Ma. The ore‐related granitoids are mostly calc‐alkaline I‐type granites, derived from partial melting of the Precambrian basement rocks with various degrees of involvement of mantle components. Combined with the regional tectonic evolution, we conclude that the Cu mineralization in the EKO began with the closure of A'nyemaqen Ocean (~238 Ma) and subsequently culminated in a postcollisional setting (~225 Ma).
Implications of U–Pb detrital zircon geochronology analysis for the depositional age, provenance, and tectonic setting of continental Mesozoic formations in the East Malaya Terrane, Peninsular Malaysia
Authors: Basori Mohd Basril Iswadi , Leman Mohd Shafeea , Zaw Khin , Meffre Sebastien , Large Ross Raymond , Mohamed Kamal Roslan , Makoundi Charles , Mohd Zin Mazlinfalina
Published: January 2018

Mesozoic strata in the East Malaya Terrane of Peninsular Malaysia record a long but poorly constrained history of basin evolution. In this study, we report LA‐ICP‐MS U–Pb geochronology analyses of detrital zircons in the continental Mesozoic sequences from the Bertangga and Gerek formations of Peninsular Malaysia, with the aim to constrain the depositional ages and provenances of the continental Mesozoic strata as well as the Mesozoic tectonic evolution of the East Malaya Terrane. The Bertangga Formation yields populations of U–Pb zircon ages of Jurassic (139 to 194 Ma), Permo−Triassic (226 to 274 Ma), Ordovician−Devonian (372 to 459 Ma), Neoproterozoic (631 to 876 Ma), and Mesoproterozoic−Palaeoproterozoic (1,448 to 2,629 Ma). In contrast, the Gerek Formation yields significant Carboniferous grains, but with an approximate zircon age range relative to the Bertangga Formation. The new data indicate a maximum Late Jurassic depositional age for the previously undated Bertangga Formation. Similarly, young zircon grain ages in the Gerek Formation also indicate a maximum Late Jurassic depositional age. Collectively, these results on detrital zircons correlate well with a regional tectonic uplift and erosion to a tectonic stability of the East Malaya Terrane basin during the Mesozoic.
Late Cretaceous tectono–magmatic event in Songliao Basin, NE China: New insights from mafic dyke geochronology and geochemistry analysis
Authors: Cheng Yinhang , Li Ying , Wang Shaoyi , Li Yanfeng , Ao Cong , Li Jianguo , Sun Lixin , Li Hongliang , Zhang Tianfu
Published: January 2018

The ages and source of Late Cretaceous mafic dolerite dykes of the Songliao Basin were determined using geochronological, geochemical, zircon Hf, whole‐rock Sr–Nd isotopic, and zircon fission tract. The results show that (a) petrographic data reveal doleritic, poikiloblastic textures, and amygdale structures of the dolerite dykes. (b) LA‐MC‐ICP‐MS U–Pb analysis of zircons yielded an age of 70.0 ± 3.0 Ma of one of these mafic dykes in agreement with the zircon fission track age (69–68 Ma) of host rocks within uncertainty, placing them within the Late Cretaceous. (c) Geochemical researches indicate that the dykes are classified as the alkaline and tholeiitic series according to their major elements and characterized by high Na2O (2.79–4.89 wt.%), TiO2 (1.63–2.71 wt.%), and low K2O (0.46–2.45 wt.%). And they have enrichment of incompatible elements (e.g., K, Ti, Rb, Ba, Th, U, Nb, Ta, and REEs), high Rb/Sr (0.026–0.066), LaN/YbN (3.83–15.93), near‐chondritic HREEs ([Gd/Yb]N = 1.78–3.37), low Sm/Nd (0.202–0.282) ratios, and with negligible Eu anomalies (Eu/Eu* = 0.98–1.06). The dykes contain relatively low amounts of radiogenic Sr, as shown by (87Sr/86Sr)i values (0.7037–0.7045), and have positive values of εNd(t) (3.66–5.40) and εHf (t) (2.66–7.45), suggesting that the mafic dykes have been derived from partial melting of the depleted lithospheric mantle and contaminated by crust in the source region and formed in back‐arc rift settings caused by the subduction of the Pacific Oceanic Plate. All the above indicate large‐scale extensional event in Songliao Basin NE China at about 70 Ma.
Near‐surface hydraulic conductivity of northern hemisphere glaciers
Authors: Stevens Ian T. , Irvine‐Fynn Tristram D.L. , Porter Philip R. , Cook Joseph M. , Edwards Arwyn , Smart Martin , Moorman Brian J. , Hodson Andy J. , Mitchell Andrew C.
Published: January 2018

The hydrology of near‐surface glacier ice remains a neglected aspect of glacier hydrology despite its role in modulating meltwater delivery to downstream environments. To elucidate the hydrological characteristics of this near‐surface glacial weathering crust, we describe the design and operation of a capacitance‐based piezometer that enables rapid, economical deployment across multiple sites and provides an accurate, high‐resolution record of near‐surface water‐level fluctuations. Piezometers were employed at 10 northern hemisphere glaciers, and through the application of standard bail–recharge techniques, we derive hydraulic conductivity (K) values from 0.003 to 3.519 m day−1, with a mean of 0.185 ± 0.019 m day−1. These results are comparable to those obtained in other discrete studies of glacier near‐surface ice, and for firn, and indicate that the weathering crust represents a hydrologically inefficient aquifer. Hydraulic conductivity correlated positively with water table height but negatively with altitude and cumulative short‐wave radiation since the last synoptic period of either negative air temperatures or turbulent energy flux dominance. The large range of K observed suggests complex interactions between meteorological influences and differences arising from variability in ice structure and crystallography. Our data demonstrate a greater complexity of near‐surface ice hydrology than hitherto appreciated and support the notion that the weathering crust can regulate the supraglacial discharge response to melt production. The conductivities reported here, coupled with typical supraglacial channel spacing, suggest that meltwater can be retained within the weathering crust for at least several days. Not only does this have implications for the accuracy of predictive meltwater run‐off models, but we also argue for biogeochemical processes and transfers that are strongly conditioned by water residence time and the efficacy of the cascade of sediments, impurities, microbes, and nutrients to downstream ecosystems. Because continued atmospheric warming will incur rising snowline elevations and glacier thinning, the supraglacial hydrological system may assume greater importance in many mountainous regions, and consequently, detailing weathering crust hydraulics represents a research priority because the flow path it represents remains poorly constrained.