bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of PKCδ autophosphorylation in U87 MG glioma cells: combination of experimental, conceptual and numerical approaches
Authors: Misuth Matus , Joniova Jaroslava , Belej Dominik , Hrivnak Stanislav , Horvath Denis , Huntosova Veronika
Published: May 2016

Golgi apparatus (GA) is a center for lipid metabolism and the final target of ceramide pathway, which may result in apoptosis. In this work localization of highly hydrophobic hypericin is followed by time‐resolved imaging of NBDC6 (fluorescent ceramide) in U87 MG glioma cells. Decrease of NBDC6 fluorescence lifetimes in cells indicates that hypericin can also follow this pathway. It is known that both, ceramide and hypericin can significantly influence protein kinase C (PKC) activity. Western blotting analysis shows increase of PKCδ autophosphorylation at Ser645 (p(S645)PKCδ) in glioma cells incubated with 500 nM hypericin and confocal‐fluorescence microscopy distinguishes p(S645)PKCδ localization between GA related compartments and nucleus. Experimental and numerical methods are combined to study p(S645)PKCδ in U87 MG cell line. Image processing based on conceptual qualitative description is combined with numerical treatment via simple exponential saturation model which describes redistribution of p(S645)PKCδ between nucleus and GA related compartments after hypericin administration. These results suggest, that numerical methods can significantly improve quantification of biomacromolecules (p(S645)PKCδ) directly from the fluorescence images and such obtained outputs are complementary if not equal to typical used methods in biology.

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Medical imaging and consent: when is an X‐ray assault?
Authors: Lane Andrea N.
Published: May 2016

New Zealand patients have rights in relation to their healthcare including the right to consent to medical treatment. Medical imaging is the third largest category of hospital procedure in New Zealand and it constitutes a circumstance where examination without consent could be assault. New Zealand assault law is unique, and medical radiation technologists (MRTs) must be educated about their responsibilities. A literature review was conducted focusing on the medicolegal aspects of consent as it relates to medical imaging. This was compared to the practical realities of practicing radiography as experienced by the author. Finally, the guidance given by the professional bodies for MRTs in New Zealand was examined to determine whether it adequately informs MRTs of the responsibilities and provides them with a framework to guide their practice. Medical imaging is a diverse area presenting a range of challenging circumstances for consent. Currently, the consent framework and guidance provided by professional bodies is insufficient and in need of updating.
Metastasectomy, intralesional resection, or stabilization only in the treatment of bone metastases from renal cell carcinoma
Authors: Langerhuizen David W.G. , Janssen Stein J. , van der Vliet Quirine M.J. , Raskin Kevin A. , Ferrone Marco L. , Hornicek Francis J. , Schwab Joseph H. , Lozano‐Calderón Santiago A.
Published: May 2016

Background

The mainstay of treatment for bone metastases from renal cell carcinoma is surgery. We assessed if there was a difference in local recurrence, reoperation, and survival between patients who underwent metastasectomy, intralesional curettage, or stabilization only for renal cell carcinoma metastasis to the appendicular skeleton, and if there was a difference in these outcomes based on margin status.

Methods

This retrospective study included 183 patients; 48% underwent metastasectomy (n = 88, margins: 64 negative; 20 positive; 4 unclear), 30% intralesional curettage (n = 54), and 22% stabilization only (n = 41).

Results

The recurrence rate differed and was highest after stabilization only (39%), followed by intralesional curettage (22%), and metastasectomy (12%) (P = 0.003). However, we found no difference in reoperation rate (P = 0.847). Survival was better in patients who underwent metastasectomy (P = 0.020). The recurrence rate was lower in patients who had a negative margin (5%) as compared to those with a positive margin (26%) (P < 0.001). However, we found no difference in reoperation rate (P = 0.97). Negative margins showed better survival (P < 0.001).

Conclusions

Our findings emphasize the importance of obtaining negative margins in patients with a good life expectancy, as lower recurrence rate can be attained at a not significant additional risk for reoperation, with a potential impact on survival. J. Surg. Oncol. 2016;114:237–245. © 2016 Wiley Periodicals, Inc.
Analysis of volatile organic compounds in pleural effusions by headspace solid‐phase microextraction coupled with cryotrap gas chromatography and mass spectrometry
Authors: Huang Zhongping , Zhang Jie , Zhang Peipei , Wang Hong , Pan Zaifa , Wang Lili
Published: May 2016

Headspace solid‐phase microextraction coupled with cryotrap gas chromatography and mass spectrometry was applied to the analysis of volatile organic compounds in pleural effusions. The highly volatile organic compounds were separated successfully with high sensitivity by the employment of a cryotrap device, with the construction of a cold column head by freezing a segment of metal capillary with liquid nitrogen. A total of 76 volatile organic compounds were identified in 50 pleural effusion samples (20 malignant effusions and 30 benign effusions). Among them, 34 more volatile organic compounds were detected with the retention time less than 8 min, by comparing with the normal headspace solid‐phase microextraction coupled with gas chromatography and mass spectrometry method. Furthermore, 24 volatile organic compounds with high occurrence frequency in pleural effusion samples, 18 of which with the retention time less than 8 min, were selected for the comparative analysis. The results of average peak area comparison and box‐plot analysis showed that except for cyclohexanone, 2‐ethyl‐1‐hexanol, and tetramethylbenzene, which have been reported as potential cancer biomarkers, cyclohexanol, dichloromethane, ethyl acetate, n‐heptane, ethylbenzene, and xylene also had differential expression between malignant and benign effusions. Therefore, the proposed approach was valuable for the comprehensive characterization of volatile organic compounds in pleural effusions.
Polymer‐Chlorambucil Drug Conjugates: A Dynamic Platform of Anticancer Drug Delivery
Authors: Saha Biswajit , Haldar Ujjal , De Priyadarsi
Published: May 2016

Recently, polymer drug conjugates (PDCs) have attracted considerable attention in the treatment of cancer. In this work, a simple strategy has been developed to make PDCs of an antitumor alkylating agent, chlorambucil, using a biocompatible disulphide linker. Chlorambucil‐based chain transfer agent was used to prepare various homopolymers and block copolymers in a controlled fashion via reversible addition–fragmentation chain transfer polymerization. Chlorambucil conjugated block copolymer, poly(polyethylene glycol monomethyl ether methacrylate)‐b‐poly(methyl methacrylate), formed nanoaggregates in aqueous solutions, which are characterized by dynamic light scattering and field emission‐scanning electron microscopy. Finally, the simplicity of the design is exemplified by performing a release study of chlorambucil under reducing condition by using D,L‐dithiothreitol.

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Polysiloxane‐Based Autonomic Self‐Healing Elastomers Obtained through Dynamic Boronic Ester Bonds Prepared by Thiol–Ene “Click” Chemistry
Authors: Zuo Yujing , Gou Zhiming , Zhang Changqiao , Feng Shengyu
Published: May 2016

Cross‐linked silicone elastomers constructed with dynamic‐covalent boronic esters are first synthesized by photoinitiated radical thiol−ene “click” chemistry. The resultant samples can be cut with a sharp knife into two pieces and then healed via the reversibility of the boronic ester cross‐linkages to restore the original silicone sample within 30 min. Regulation of luminescent properties is achieved by incorporating organic dye into the elastomers through a “one‐pot” thiol–ene reaction. The proposed synthesis procedure demonstrates a new strategy to produce boronic acid silicone materials capable of self‐healing without external forces.

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Free temporal artery posterior auricular skin (TAPAS) flap: A new option in facial and intra‐oral reconstruction
Authors: Lassus Patrik , Lindford Andrew J.
Published: May 2016

Background

There is a limited availability of suitable microvascular free flap options for the reconstruction of small to medium‐sized facial and intraoral defects. The purpose of this report is to present a new free temporal artery based posterior auricular skin (TAPAS) flap in facial and intraoral reconstruction.

Patients and Methods

Four patients were deemed suitable for TAPAS flap reconstruction and consisted of two males and two females with a mean age of 43 years (range 22–66). Defect aetiology and location comprised of post‐traumatic lower eyelid scarring, late lower lip scarring post tumour resection, and floor of mouth and tongue defects following tumour resection. The dimensions of the resultant defects ranged from 25 × 50 mm (smallest) to 40 × 70 mm (largest). All patients underwent microvascular reconstruction using a free fasciocutaneous TAPAS flap raised from the retroauricular region based on the superficial temporal vessels.

Results

The maximal pedicle length was 60 mm and the maximum flap size measured 40 mm by 70 mm. The latter patient required skin grafting of the postauricular donor site. Postoperatively, there was one case of mild transient venous congestion that spontaneously resolved after 2 days and one case of minor partial flap dehiscence that required re‐suturing. Follow‐up time ranged from 6 to 14 months. Overall, all flaps survived with good aesthetic and functional outcome.

Conclusion

The TAPAS flap is a small flap with exceptional qualities and may be a useful addition to the armamentarium of free flaps in facial and oral reconstructions. © 2016 Wiley Periodicals, Inc. Microsurgery 37:525–530, 2017.
Eicosapentaenoic acid and arachidonic acid differentially regulate adipogenesis, acquisition of a brite phenotype and mitochondrial function in primary human adipocytes
Authors: Fleckenstein‐Elsen Manuela , Dinnies Daniela , Jelenik Tomas , Roden Michael , Romacho Tania , Eckel Jürgen
Published: May 2016

Scope

n‐3 and n‐6 PUFAs have several opposing biological effects and influence white adipose tissue (WAT) function. The recent discovery of thermogenic UCP1‐expressing brite adipocytes within WAT raised the question whether n‐3 and n‐6 PUFAs exert differential effects on brite adipocyte formation and mitochondrial function.

Methods and results

Primary human preadipocytes were treated with n‐3 PUFAs (eicosapentaenoic acid, EPA; docosahexaenoic acid, DHA) or n‐6 PUFA (arachidonic acid, ARA) during differentiation, and adipogenesis, white and brite gene expression markers, mitochondrial content and function were analyzed at day 12 of differentiation. Adipogenesis was equally increased by n‐3 and n‐6 PUFAs. The n‐6 PUFA ARA increased lipid droplet size and expression of the white‐specific marker TCF21 while decreased mitochondrial protein expression and respiratory function. In contrast, EPA increased expression of the brown adipocyte‐related genes UCP1 and CPT1B, and improved mitochondrial function of adipocytes. The opposing effects of EPA and ARA on gene expression and mitochondrial function were also observed in cells treated from day 8 to 12 of adipocyte differentiation.

Conclusion

EPA promotes brite adipogenesis and improves parameters of mitochondrial function, such as increased expression of CPTB1, citrate synthase activity and higher maximal respiratory capacity, while ARA reduced mitochondrial spare respiratory capacity in vitro.
Urolithins, the rescue of “old” metabolites to understand a “new” concept: Metabotypes as a nexus among phenolic metabolism, microbiota dysbiosis, and host health status
Authors: Tomás‐Barberán Francisco A. , González‐Sarrías Antonio , García‐Villalba Rocío , Núñez‐Sánchez María A. , Selma María V. , García‐Conesa María T. , Espín Juan Carlos
Published: May 2016

Urolithins are dibenzo[b,d]pyran‐6‐one derivatives that are produced by the human gut microbiota from ellagitannins and ellagic acid (EA). These metabolites are much better absorbed than their precursors and have been suggested to be responsible for the health effects attributed to ellagitannins and EA that occur in food products as berries and nuts. In the present review, the role and potential of urolithins in human health are critically reviewed, and a perspective of the research approach needed to demonstrate these health effects is presented, based on the existing knowledge. The analytical methods available for urolithin analysis, their occurrence in different tissues and biological fluids, and their metabolism by human gut microbiota are considered. In addition, the interindividual variability observed for the production of urolithins (metabotypes) and its relationship with health status and dysbiosis are also reviewed. The potential mechanisms of action of urolithins are also critically discussed, paying attention to the concentration and the type of metabolites used in the in vitro and in vivo assays and the physiological significance of the results obtained. The gut microbiota metabolism of EA to urolithins and that of daidzein to equol, their individual variations, and the effects on health are also compared.
Numerical simulation and experimental validation of liquid‐film‐flow characteristics in dip coating for non‐Newtonian fluids
Authors: Zhang Xian‐Ming , Chen Meng‐Meng , Ma Jian‐Ping , Chen Wen‐Xing , Feng Lian‐Fang
Published: May 2016

The film‐flow problem in dip coating is simulated numerically for non‐Newtonian fluids based on Carreau–Yasuda (CY) and Herschel–Bulkley (HB) constitutive equations, with particular focus on coating‐film‐thickening phenomena and on the evolution of free surface and flow field under different sets of conditions. Finite element method (FEM) is combined with remeshing technique using a commercial code (Polyflow). Numerical predictions of the final film thickness and free surface for HB and CY fluids are successfully compared with experiments under the given conditions. Results show that the combination of FEM‐remeshing technique could be useful for dip‐coating design and optimization. Effects of coating fluid properties and withdrawal speed on film thickening and free surface shape and location are also discussed. Flow fields under different conditions are presented to analyze the evolution of the entire flow field and flow characteristics in detail. POLYM. ENG. SCI. 56:1070–1078, 2016. © 2016 Society of Plastics Engineers
Charge transport and contact resistance in coplanar devices based on colloidal polyaniline dispersion
Authors: Masillamani Appan Merari , Peřinka Nikola , Hajná Milena , Stejskal Jaroslav , Tondelier Denis , Bonnassieux Yvan , Vanel Jean‐Charles , Geffroy Bernard , Mencaraglia Denis
Published: May 2016

The charge transport properties of thin films prepared from colloidal dispersion of polyaniline stabilized by poly(N‐vinylpyrrolidone) (PANI/PVP) have been investigated. The electrical characterization of coplanar device comprising of gold electrodes and PANI/PVP film deposited by spin coating served to gain insights into the contact and bulk resistance. The films prepared from PANI/PVP colloidal dispersion show high stability over a large temperature range. Temperature dependent measurements in the range from 90 to 350 K reveal that the charge transport can be described by a three‐dimensional variable‐range hopping mechanism as the dominant mode in the films. The stability of the films cast from dispersion within a large temperature range opens the possibility of the application as a polymer semiconductor layer in sensors and charge‐transport interlayer in organic solar cells. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 1710–1716
Covalent and Ionic Insensitive High‐Explosives
Authors: Klapötke Thomas M. , Witkowski Tomasz G.
Published: May 2016

Ongoing research into new insensitive energetic materials with low sensitivity toward accidental stimuli, high thermal stability and high performance characteristics is undertaken in many research groups worldwide. In order to obtain promising compounds, which fulfil the sensitivity, stability, and performance requirements, researchers use many different strategies. One of the most promising approaches is the synthesis of novel explosives with tailored physico‐chemical properties. In this review the synthesis and properties of some both covalent (NTO, TEX, FOX‐7, ADNP, DNPPs) and ionic (salts of ANDP and DNPP) insensitive explosives are presented, which are of high interest to this field of research.
Dispersive Plasmon Damping in Single Gold Nanorods by Platinum Adsorbates
Authors: Xu Pengyu , Lu Xuxing , Han Song , Ou Weihui , Li Yue , Chen Sheng , Xue Junfei , Ding Yaping , Ni Weihai
Published: May 2016

Surface modifications of plasmonic nanoparticles with metal adsorbates are essential in applications such as plasmonic sensing, plasmon‐enhanced photocatalysis, etc., where spectral broadening is usually observed. A single particle study is presented on plasmon damping by adsorption of platinum (Pt) clusters. Single particle dark‐field spectroscopy is employed to measure exactly the same gold nanorod before and after the Pt adsorption. The Pt‐induced plasmon damping in terms of linewidth increase is found dependent on the resonance wavelength of the measured nanorod, which is dispersive in nature. The measured dispersion generally matches the theoretical prediction, and it basically exhibits a gradual increase with decreasing resonance energy. This increase can be attributed to the fact that the nanorod as a better resonator is more susceptible to the Pt adsorption than the spherical particles. Moreover, simulated results based on discrete dipole approximation method further indicate that the damping is mainly contributed from the adsorbates on the ends of the nanorod and independent on the type of the metal adsorbed. Knowledge and insights gained in this study can be very important for the design and fabrication of plasmonic heterostructures as functional nanomaterials.
Portosystemic Shunts for “Too Small‐for‐Size Syndrome” After Liver Transplantation: A Systematic Review
Authors: Kinaci Erdem , Kayaalp Cuneyt
Published: May 2016

Background

Portosystemic shunts (PSSs) modulate the portal hyperperfusion against small‐for‐size syndrome (SFSS) after split or living donor liver transplantation.

Aim

To find out the results and the limitations of PSSs against SFSS.

Materials and methods

We searched PubMed and Cochrane databanks for systematic review and analyzed the indications, types, morbidities, and survivals of the PSSs at split or living donor liver transplantations.

Results

Total 66 patients were assessed in 16 studies. Main indications for PSS were graft recipient weight ratio (GRWRs) <0.8 % and/or portal vein pressure >20 mmHg. Five different types of PSSs were described but hemi‐portocaval shunts were the most common one. The incidence of SFSS was 12 %. Overall 90‐day, 1‐, and 3‐year graft survivals were 80, 70, and 47 %, respectively. GRWR <0.65 % was found as the only significant parameter on graft survival. The 90‐day, 1‐ and 3‐year graft survivals for GRWR <0.65 and ≥0.65 % patients were 62.5, 42.8, and 30.0 and 95, 94, and 67 %, respectively (p = 0.03, p = 0.01, and p = 0.18).

Conclusion

PSSs can modulate the small graft size (GRWR < 0.8 %) and/or portal hypertension (>20 mmHg) after split or living donor liver transplantations sufficiently. However, its protective effect is not unlimited. If the GRWR is below 0.65 %, survival decreases significantly despite PSSs.
A Systematic Review of Economic Analysis of Surgical Mission Trips Using the World Health Organization Criteria
Authors: Nolte Michael T. , Maroukis Brianna L. , Chung Kevin C. , Mahmoudi Elham
Published: May 2016

Background

Although the World Health Organization (WHO) has developed tools to standardize economic evaluations of global health interventions, little is known about the cost‐effectiveness of surgical mission trips and their economic values. Our objective was to systematically evaluate the current literature on surgical volunteering trips to measure their adherence to WHO CHOosing Interventions that are cost‐effective (WHO‐CHOICE). We hypothesized that the majority of studies use some type of cost‐effectiveness analysis that do not adhere to these standards.

Methods

A systematic review of Pubmed, Medline, and Embase databases was performed in accordance with PRISMA guidelines, with inclusion criteria set a priori. Of the 908 publications screened, 72 were selected for full text review; 17 met inclusion criteria.

Results

Only 17 out of 72 studies reported some type of economic analysis. We categorized the studies into service, educational, and combination (service and educational) surgical trips. Although seven of the service studies calculated the cost per disability‐adjusted life year averted, the results were not based on WHO‐CHOICE standards to facilitate comparisons among alternative options. Furthermore, none of the three educational trips calculated the value of the education provided, but only published cost estimates of the resources used during the trip.

Conclusions

Although a few studies performed some type of economic analysis, owing to their non‐adherence to WHO‐CHOICE standards, the results were not comparable to other studies. International surgical trips are expensive. To improve the efficacy and optimal use of limited resources, studies on surgical trips should follow the guidelines set by the WHO‐CHOICE.
One Pot Synthesis and Properties of Cationic Surfactants: n‐Alkyl‐3‐Methylpyridinium Bromide
Authors: Fayyaz Summaira , Ali Saqib , Khalid Nasir , Shah Afzal , Ullah Faizan
Published: May 2016

Three new amphiphilic compounds i.e., n‐decyl‐3‐methylpyridinium bromide (a), n‐dodecyl‐3‐methylpyridinium bromide (b), and n‐tetradecyl‐3‐methylpyridinium bromide (c), have been synthesized by condensation reaction and characterized by NMR (1H, 13C) and FTIR spectroscopic techniques. The micellization behavior of the compounds has been studied in ethanol employing conductometry and UV/visible spectroscopy. The critical micellization concentration (CMC) values for compound a, b and c was found to be 0.31, 0.29 and 0.27 m mol L−1, respectively. Effect of temperature on the CMC was checked in the range of 298‐318 K. The thermodynamic parameters such as ΔG, ΔH and ΔS of the micellization process of these surfactants were computed. The negative values of ΔG and positive values of ΔH indicated the spontaneous and endothermic nature of the micellization process. Antimicrobial activities of these amphiphiles showed significant activity against different bacterial strains.
Resection of ischiorectal fossa tumors – surgical technique
Authors: Filho Eduardo Fonseca Alves , de Carvalho Alexandre Lopes , de Oliveira Costa Paulo Frederico , de Carvalho Antonio Carlos
Published: May 2016

Primary tumors of the ischiorectal fossa are rare, they can be congenital, acquired or neoplastic. Accurate diagnosis often cannot be done preoperatively and imaging studies such as computed tomography and especially magnetic resonance imaging can define the size and anatomical relationships of the lesions. Surgical treatment is challenging because of difficult access of the region which is preferably performed by posterior approach. We describe the etiology, diagnosis and operative technique of tumors of the ischiorectal fossa.
Early Miocene Formicidae (Amblyoponinae, Ectatomminae, ?Dolichoderinae, Formicinae, and Ponerinae) from the Foulden Maar Fossil Lagerstätte, New Zealand, and their biogeographic relevance
Authors: Kaulfuss Uwe , Dlussky Gennady M.
Published: May 2016

The fossil record of Australasian Formicidae is extremely sparse. It currently comprises two ants in the subfamilies Ponerinae and Dolichoderinae from Plio/Pleistocene strata in Victoria, Australia, 14 as-yet undescribed ants from Cape York amber, and one ant in the subfamily Amblyoponinae from the early Miocene Foulden Maar in southern New Zealand. Here, we report on a diverse myrmecofauna preserved as compression fossils from Foulden Maar and describe Amblyoponinae gen. et sp. indet.,Rhytidoponera waipiatan. sp.,Rhytidoponera gibsonin. sp.,Myrmecorhynchus novaeseelandiaen. sp., andAustroponera schneiderin. sp. Further isolated wings are designated as Formicidae sp. A, B, and C, the former resembling a member of subfamily Dolichoderinae. Fossils ofAustroponeraandMyrmecorhynchusare reported for the first time, whereasRhytidoponera waipiatan. sp. andR.gibsonin. sp. are the first Southern Hemisphere fossil records of this genus.

The fossil taxa from Foulden Maar establish the subfamilies Ectatomminae, Formicinae, Ponerinae and, possibly, Dolichoderinae in the Australasian region in the early Miocene and provide evidence that the few native ants in the extant New Zealand fauna are the surviving remnant of taxonomically different, possibly more diverse, warm-temperate to subtropical myrmecofauna.
The first mastotermitid termite from Africa (Isoptera: Mastotermitidae): a new species ofMastotermesfrom the early Miocene of Ethiopia
Authors: Engel Michael S. , Currano Ellen D. , Jacobs Bonnie F.
Published: May 2016

The first mastotermitid termite from Africa is described and figured from wing fragments recovered from the early Miocene (22–21 Ma) deposits of the Mush Valley, Amhara Region, central Ethiopia.Mastotermes aethiopicusnew species is the second fossil termite recorded from Africa and expands the known paleo-distribution of the genus from tropical North America and Europe into northeastern Africa during the Miocene.Mastotermes aethiopicusis distinguished from the livingM.darwiniensisFroggatt and other Neogene species of the genus, and comments are provided regarding the occurrence of this genus in the tropical fauna of Miocene Ethiopia.
A new Eocene genus of ant-like stone beetles sheds new light on the evolution of Mastigini
Authors: Jałoszyński Paweł
Published: May 2016

Fossil Scydmaeninae beetles are exceptionally poorly known and those described usually lack important details to reliably analyze their phylogenetic relationships with extant taxa.Baltostigusn. gen. is the first extinct ant-like stone beetle taxon unambiguously assigned to the tribe Mastigini. It includesB.antennatusn. sp. (the type species ofBaltostigus) andB.horribilisn. sp., from the lower to middle Eocene amber of Poland and Lithuania, respectively. Results of a phylogenetic analysis comprising morphological characters of all extant and extinct genera of the supertribe Mastigitae strongly support the placement ofBaltostigusas a sister group to all remaining Mastigini. The new genus shows character states not known in any extant Mastigini: fully developed hind wings, prominent humeral calli, deep elytral punctures partly arranged in longitudinal rows and symmetrical aedeagal parameres. These features suggest that Mastigini might have evolved from forms morphologically similar to small-bodied extant Clidicini of the ‘Leptochromuslineage.’
Bivalved arthropods from the Middle Ordovician Winneshiek Lagerstätte, Iowa, USA
Authors: Briggs Derek E.G. , Liu Huaibao P. , McKay Robert M. , Witzke Brian J.
Published: May 2016

The Middle Ordovician (Darriwilian) Winneshiek Lagerstätte of northeast Iowa is preserved in a meteorite crater. Besides conodonts, the fossils are dominated by arthropods, particularly eurypterids and phyllocarids. Here we describe the bivalved forms, which include at least seven different taxa. The small phyllocaridCeratiocaris winneshiekensis, new species, is the most abundant; it is the oldest representative of the Ceratiocarididae. A single incomplete abdomen and telson bearing furcal rami is reminiscent of notostracan branchiopods but its affinities are unknown.Decoracaris hildebrandi, new genus and species, is a rare form with a shield that extends anteriorly into a swollen horn and reaches lengths of 9 cm: it may represent a thylacocephalan crustacean but this cannot be confirmed without soft parts.Iosuperstes collisionis, new genus and species, is represented by suboval valves 10–25 mm long: its affinities are unknown. A probable leperditicopid, which ranges in length from 8 to 18 mm, is commonly preserved in a ‘butterflied’ configuration. It does not preserve the scars and sinuses characteristic of three-dimensionally preserved leperditicopids from elsewhere. Finally the fauna includes at least three ostracods, including a palaeocope with a granular surface and relief similar toLomatopisthia, and a smooth ?podocope. The Winneshiek fauna differs from those of other Ordovician Lagerstätten from restricted settings such as Airport Cove and William Lake in Manitoba (Katian) where, apart from ostracods, bivalved arthropods are absent, and Silurian examples such as Brandon Bridge (Telychian), which lacks eurypterids, and the Williamsville Member of the Bertie Formation (Pridoli) where conodont assemblages are absent.
A new genusLiaousof early Anisian Stage (Middle Triassic) brachiopods from southwestern China: systematics, reassessment of classification of the Spiriferinioidea, community paleoecology, and paleoenvironmental implications
Authors: He Weihong , Zhang Kexin , Chen Zhong-Qiang , Yan Jiaxin , Yang Tinglu , Zhang Yang , Gu Songzhu , Wu Shunbao
Published: May 2016

This paper describes a new genusLiaous, withL. shaiwensisHe and Chen n. gen. n. sp. as the type species, from the Xinyuan Formation of Anisian age in Ziyun, southern Guizhou, China. The phylogenetic tree revealed by the parsimony analysis shows thatLiaousis closely allied to bothMentzeliaQuenstedt, 1871 andParamentzeliaXu, 1978 of the subfamily Mentzeliinae. A new classification scheme for the Spiriferinoidea is also proposed based on a phylogenetic tree of the superfamily indicated by parsimony analysis. The Spiriferinoidea includes three families and nine subfamilies. Three new subfamilies—Madoinae He and Chen, new subfam., Qinghaispiriferininae He and Chen, new subfam., and Triadispirinae He and Chen, new subfam. are proposed.Liaous shaiwensisHe and Chen n. gen. n. sp. is found in thePosidonia wengensis-Liaous shaiwensis(P-L) paleocommunity, which is dominated by r-strategists (i.e., organisms defined by a fauna with a high dominance and small body sizes) and has a low diversity and high dominance. The P-L paleocommunity therefore has little similarity to its coeval communities from the Anisian Stage of South China and instead it appears more similar to the Lower Triassic shelly faunas in community structures. This paleocommunity is interpreted to have inhabited a relatively deep, low-energy, dysaerobic offshore basin/slope setting with the influence of episodic storms.
Exceptionally preservedMickwitziafrom the Indian Springs Lagerstätte (Cambrian Stage 3), Nevada
Authors: Butler Aodhán D. , Streng Michael , Holmer Lars E. , Babcock Loren E.
Published: May 2016

Exceptionally preserved specimens of the Cambrian stem-group brachiopodMickwitzia occidensWalcott, 1908 are described in detail from the Indian Springs Lagerstätte in Nevada, USA. Shell structure and preserved mantle setae from these specimens reveal a variable diagenetic (taphonomic) history and provide insight into the phylogenetic position of mickwitziids. Morphologic and morphometric comparison toM. monilifera(Linnarsson, 1869) from Sweden andM. muralensisWalcott, 1913 from British Columbia, Canada reveals clear species-level distinctions. Scanning electron microscopic analysis allows revision of the generic diagnosis. TheMickwitziashell is characterized by the presence of inwardly pointing phosphatic cones and tangential setae-bearing tubes. The inwardly pointing cone structures are not consistent with setal bearing structures as previously thought, but rather represent endopunctae-like structures. Acrotretid-like shell structures and shell-penetrating setae inM. occidensstrengthen the previously proposed close relationship between stem-group brachiopods and tommotiids, a group of small shelly fossils.
Imaging of NGC 5907's stellar stream
Authors: Laine Seppo , Grillmair Carl J. , Martínez–Delgado David , Romanowsky Aaron J. , Capak Peter L. , Arendt Richard G. , Ashby Matthew L. N. , Davies James E. , Majewski Steven R. , GaBany R. Jay
Published: May 2016

We have obtained deep g, r, and i-band Subaru and ultra-deep 3.6 μm IRAC images of parts of the multiply-wrapped stellar stream around the nearby edge-on galaxy NGC 5907. We have fitted the surface brightness measurements of the stream with FSPS stellar population synthesis models to derive the metallicity and age of the brightest parts of the stream. The resulting relatively high metallicity ([Fe/H] = −0.3) is consistent with a major merger scenario but a satellite accretion event cannot be ruled out.
A universality of dark-halo surface density for the Milky Way and Andromeda dwarf satellites as a probe of the coldness of dark matter
Authors: Hayashi Kohei , Chiba Masashi
Published: May 2016

We propose a new astrophysical test on the nature of dark matter based on the properties of dark halos associated with dwarf spheroidal galaxies. The method adopts a mean surface density of a dark halo defined within a radius of maximum circular velocity, which is derivable for a wide variety of galaxies with any dark-matter density profiles. We find that even though dark halo density profiles are derived based on the different assumptions for each galaxy sample, this surface density is generally constant across a wide mass range of galaxy. We find that at higher halo-mass scales, this constancy for real galaxies can be naturally reproduced by both cold and warm dark matter (CDM and WDM) models. However, at low-mass scales, for which we have estimated from the Milky Way and Andromeda dwarf satellites, the mean surface density derived from WDM models largely deviates from the observed constancy, whereas CDM models are in reasonable agreement with observations.
Globular Cluster Streams as Galactic High-Precision Scales
Authors: Küpper Andreas H.W. , Balbinot Eduardo , Bonaca Ana , Johnston Kathryn V. , Hogg David W. , Kroupa Pavel , Santiago Basilio X.
Published: May 2016

Tidal streams of globular clusters are ideal tracers of the Galactic gravitational potential. Compared to the few known, complex and diffuse dwarf-galaxy streams, they are kinematically cold, have thin morphologies and are abundant in the halo of the Milky Way. Their coldness and thinness in combination with potential epicyclic substructure in the vicinity of the stream progenitor turns them into high-precision scales. With the example of Palomar 5, we demonstrate how modeling of a globular cluster stream allows us to simultaneously measure the properties of the disrupting globular cluster, its orbital motion, and the gravitational potential of the Milky Way.
Identifying Remote Halo Giants in High-Latitude Fields with Kepler 2
Authors: Peterson Ruth C.
Published: May 2016

This work sketches how SDSSugrcolors and Kepler 2 in halo fields can identify red giants 50 – 100 kpc distant with minimal metallicity bias. For these mildly-reddened, metal-poor giants, (g-r)oyields the effective temperatureTeffto 100 K. K2 can detect the p-mode oscillations of red giants and measure their frequency of maximum power νmax. This sets the luminosityLboland thus the distance, plus an estimate of metallicity [Fe/H].
Galactic Archaeology with the Subaru Prime Focus Spectrograph
Authors: Chiba Masashi , Cohen Judith , Wyse Rosemary F. G.
Published: May 2016

We present an overview of our Galactic Archaeology (GA) survey program with the Prime Focus Spectrograph (PFS) for Subaru. Following successful design reviews, the instrument is now under construction with first light anticipated in 2018. Main characteristics of PFS and the science goals in our PFS/GA program are described.
Near-Field Cosmology with RR Lyrae Variable Stars: A First View of Substructure in the Southern Sky
Authors: Navarrete C. , Duffau S. , Vivas A. K. , Catelan M. , Hajdu G. , Torrealba G. , Cortés C. , Belokurov V. , Koposov S. , Drake A. J.
Published: May 2016

We present the current status of the spectroscopic follow-up of a large number of RR Lyrae (RRL) halo overdensity candidates recently found by Torrealba et al. (2015) using southern-hemisphere data from the Catalina Real-time Transient Survey (CRTS). Characterizing the individual RRL stars in these overdensities is crucial to confirm them as real halo substructures. Low-resolution spectra have been obtained for RRL stars in 11 different overdensities, using the SOAR and Magellan telescopes. Radial velocities and metallicities have been derived so far for 123 and 99 RRL stars, respectively.
Studying stellar halos with future facilities
Authors: Greggio Laura , Falomo Renato , Uslenghi Michela
Published: May 2016

Stellar halos around galaxies retain fundamental evidence of the processes which lead to their build up. Sophisticated models of galaxy formation in a cosmological context yield quantitative predictions about various observable characteristics, including the amount of substructure, the slope of radial mass profiles and three dimensional shapes, and the properties of the stellar populations in the halos. The comparison of such models with the observations provides constraints on the general picture of galaxy formation in the hierarchical Universe, as well as on the physical processes taking place in the halos formation. With the current observing facilities, stellar halos can be effectively probed only for a limited number of nearby galaxies. In this paper we illustrate the progress that we expect in this field with the future ground based large aperture telescopes (E-ELT) and with space based facilities as JWST.
Connection between cusp-core problem and too-big-to-fail problem in CDM model
Authors: Kato Kazuki , Mori Masao , Ogiya Go
Published: May 2016

The standard paradigm of structure formation in the universe, the cold dark matter cosmology, contains several crucial unsolved problems such as “cusp-core problem” and “too-big-to-fail problem”. To solve these problems, we study about the dynamical response of a virialized system with a central cusp to the energy feedback driven by periodic supernova feedback using collisionless N-body simulations with the Nested-Particle-Mesh code. The resonance between dark matter particles and the density wave excited by the oscillating potential plays a significant role in the cusp-core transition of dark matter halos. Furthermore, we show that the cusp-core transition with periodic supernova feedback can solve the too-big-to-fail problem.
Building Blocks of the Milky Way's Stellar Halo
Authors: van Oirschot Pim , Starkenburg Else , Helmi Amina , Nelemans Gijs
Published: May 2016

We study the assembly history of the stellar halo of Milky Way-like galaxies using the six high-resolution Aquarius dark matter simulations combined with the Munich-Groningen semi-analytic galaxy formation model. Our goal is to understand the stellar population contents of the building blocks of the Milky Way halo, including their star formation histories and chemical evolution, as well as their internal dynamical properties. We are also interested in how they relate or are different from the surviving satellite population. Finally, we will use our models to compare to observations of halo stars in an attempt to reconstruct the assembly history of the Milky Way's stellar halo itself.
Lithium evolution from Pre-Main Sequence to the Spite plateau: an environmental solution to the cosmological lithium problem
Authors: Fu Xiaoting , Bressan Alessandro , Molaro Paolo , Marigo Paola
Published: May 2016

Lithium abundance derived in metal-poor main sequence stars is about three times lower than the primordial value of the standard Big Bang nucleosynthesis prediction. This disagreement is referred to as the lithium problem. We reconsider the stellar Li evolution from the pre-main sequence to the end of main sequence phase by introducing the effects of overshooting and residual mass accretion. We show that 7Li could be significantly depleted by convective overshooting in the pre-main sequence phase and then partially restored in the stellar atmosphere by residual accretion which follows the Li depletion phase and could be regulated by EUV photo-evaporation. By considering the conventional nuclear burning and diffusion along the main sequence we can reproduce the Spite plateau for stars with initial mass m0=0.62–0.80 M⊙, and the Li declining branch for lower mass dwarfs, e.g, m0=0.57–0.60 M⊙, for a wide range of metallicities (Z=0.00001 to Z=0.0005), starting from an initial Li abundance A(Li) = 2.72.
Photometric Metallicity of the Sagittarius Stream in the south Galactic cap
Authors: Du Cuihua , Gu Jiayin , Jia Yunpeng , Peng Xiyan , Wu Zhenyu , Ma Jun , Zhou Xu , Liang Yanchun
Published: May 2016

Based on SDSS and South Galactic Cap U-band Sky Survey (SCUSS) photometry, we try to study the photometric metallicity of the Sagittarius (Sgr) stream in the south Galactic cap. We find that the Sgr stream has a wider metallicity distribution, and that its median metallicity is richer than that of the field halo stars. The neighboring field halo stars in our studied fields can be modeled by a two-Gaussian model, with peaks at [Fe/H]= −1.9 and [Fe/H]= −1.5. The metallicity distribution function (MDF) of the mixed population (Sgr stream and halo stars) has peaks at [Fe/H]= −1.9, [Fe/H]= −1.5 and [Fe/H]= −0.5, respectively.
r-Process Elements as Tracers of Enrichment Processes in the Early Halo
Authors: Andersen Johannes , Nordström Birgitta , Hansen Terese T.
Published: May 2016

Significant minorities of extremely metal-poor (EMP) halo stars exhibit dramatic excesses of neutron capture elements. The standard scenario for their origin is mass transfer and dilution in binary systems, but requires them to be binaries. If not, these excesses must have been implanted in them from birth by processes that are not included in current models of SN II chemical enrichment. The binary population of such EMP subgroups is a test of this scenario.
Stellar kinematics and dark matter in dwarf galaxies
Authors: Battaglia Giuseppina
Published: May 2016

In this review I will discuss the current status on determinations of the dark matter content and distribution in Milky Way dwarf spheroidals, for which the available data-sets allow the application of sophisticated mass modeling techniques.
Resolving the extended stellar halos of nearby galaxies: the wide-field PISCeS survey
Authors: Crnojević D. , Sand D. J. , Caldwell N. , Guhathakurta P. , McLeod B. , Seth A. , Simon J. D. , Strader J. , Toloba E.
Published: May 2016

In the wide-field Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS), we investigate the resolved stellar halos of two nearby galaxies (the elliptical Centaurus A and the spiral Sculptor, D ~ 3.7 Mpc) out to a projected galactocentric radius of 150 kpc with Magellan/Megacam. The survey has led to the discovery of ~20 faint satellites to date, plus prominent streams and substructures in two environments that are substantially different from the Local Group, i.e. the Centaurus A group dominated by an elliptical and the loose Sculptor group of galaxies. These discoveries clearly attest to the importance of past and ongoing accretion processes in shaping the halos of these nearby galaxies, and provide the first census of their satellite systems down to an unprecedented MV < −8. The detailed characterization of the stellar content, shape and gradients in the extended halos of Sculptor, Centaurus A, and their dwarf satellites provides key constraints on theoretical models of galaxy formation and evolution.
Stellar populations of stellar halos: Results from the Illustris simulation
Authors: Cook B. A. , Conroy C. , Pillepich A. , Hernquist L.
Published: May 2016

The influence of both major and minor mergers is expected to significantly affect gradients of stellar ages and metallicities in the outskirts of galaxies. Measurements of observed gradients are beginning to reach large radii in galaxies, but a theoretical framework for connecting the findings to a picture of galactic build-up is still in its infancy. We analyze stellar populations of a statistically representative sample of quiescent galaxies over a wide mass range from the Illustris simulation. We measure metallicity and age profiles in the stellar halos of quiescent Illustris galaxies ranging in stellar mass from 1010 to 1012M⊙, accounting for observational projection and luminosity-weighting effects. We find wide variance in stellar population gradients between galaxies of similar mass, with typical gradients agreeing with observed galaxies. We show that, at fixed mass, the fraction of stars born in-situ within galaxies is correlated with the metallicity gradient in the halo, confirming that stellar halos contain unique information about the build-up and merger histories of galaxies.
Recent Results from SPLASH: Chemical Abundances and Kinematics of Andromeda's Stellar Halo
Authors: Gilbert Karoline M. , Beaton Rachael , Dorman Claire ,   the SPLASH collaboration
Published: May 2016

Large scale surveys of Andromeda's resolved stellar populations have revolutionized our view of this galaxy over the past decade. The combination of large-scale, contiguous photometric surveys and pointed spectroscopic surveys has been particularly powerful for discovering substructure and disentangling the structural components of Andromeda. The SPLASH (Spectroscopic and Photometric Landscape of Andromeda's Stellar Halo) survey consists of broad- and narrow-band imaging and spectroscopy of red giant branch stars in lines of sight ranging in distance from 2 kpc to more than 200 kpc from Andromeda's center. The SPLASH data reveal a power-law surface brightness profile extending to at least two-thirds of Andromeda's virial radius (Gilbertet al. 2012), a metallicity gradient extending to at least 100 kpc from Andromeda's center (Gilbertet al. 2014), and evidence of a significant population of heated disk stars in Andromeda's inner halo (Dormanet al. 2013). We are also using the velocity distribution of halo stars to measure the tangential motion of Andromeda (Beatonet al., in prep).
Age-metallicity-velocity relation of stars as seen by RAVE
Authors: Wojno Jennifer , Kordopatis Georges , Steinmetz Matthias , Matijevič Gal , McMillan Paul J. ,   the RAVE Collaboration
Published: May 2016

Throughout the past decade, significant advances have been made in the size and scope of large-scale spectroscopic surveys, allowing for the opportunity to study in-depth the formation history of the Milky Way. Using the fourth data release of the RAdial Velocity Experiment (RAVE), we study the age-metallicity-velocity space of ~ 100,000 FGK stars in the extended solar neighborhood in order to explore evolutionary processes. Combining these three parameters, we better constrain our understanding of these interconnected, fundamental processes.
Origin of strong magnetic fields in Milky Way-like galaxies
Authors: Beck Alexander M.
Published: May 2016

Magnetic fields are observed on all scales in the Universe (see e.g. Kronberg 1994), but little is known about the origin and evolution of those fields with cosmic time. Seed fields of arbitrary source must be amplified to present-day values and distributed among cosmic structures. Therefore, the emergence of cosmic magnetic fields and corresponding dynamo processes (see e.g. Zel'dovich et al. 1983; Kulsrud et al. 1997) can only be jointly understood with the very basic processes of structure and galaxy formation (see e.g. Mo et al. 2010).
Resolved Stellar Halos of M87 and NGC 5128: Metallicities from the Red-Giant Branch
Authors: Bird Sarah A.
Published: May 2016

We have searched halo fields of two giant elliptical galaxies: M87, using HST images at 10 kpc from the galactic center, and NGC 5128 (Cen A), using VIMOS VLT images at 65 kpc from the center and archival HST data from 8 to 38 kpc from the center. We have resolved thousands of red-giant-branch (RGB) stars in these stellar halo fields using V and I filters, and, in addition, measured the metallicity using stellar isochrones. The metallicity distribution function (MDF) of the inner stellar halo of M87 is similar to that of NGC 5128's stellar halo.