bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in microbial communities along redox gradients in polygonized Arctic wet tundra soils
Authors: Lipson David A. , Raab Theodore K. , Parker Melanie , Kelley Scott T. , Brislawn Colin J. , Jansson Janet 
Published: June 2015

SummaryThis study investigated how microbial community structure and diversity varied with depth and topography in ice wedge polygons of wet tundra of the Arctic Coastal Plain in northern Alaska and what soil variables explain these patterns. We observed strong changes in community structure and diversity with depth, and more subtle changes between areas of high and low topography, with the largest differences apparent near the soil surface. These patterns are most strongly correlated with redox gradients (measured using the ratio of reduced Fe to total Fe in acid extracts as a proxy): conditions grew more reducing with depth and were most oxidized in shallow regions of polygon rims. Organic matter and pH also changed with depth and topography but were less effective predictors of the microbial community structure and relative abundance of specific taxa. Of all other measured variables, lactic acid concentration was the best, in combination with redox, for describing the microbial community. We conclude that redox conditions are the dominant force in shaping microbial communities in this landscape. Oxygen and other electron acceptors allowed for the greatest diversity of microbes: at depth the community was reduced to a simpler core of anaerobes, dominated by fermenters (Bacteroidetes and Firmicutes).
Oasis desert farming selects environment‐specific date palm root endophytic communities and cultivable bacteria that promote resistance to drought
Authors: Cherif Hanene , Marasco Ramona , Rolli Eleonora , Ferjani Raoudha , Fusi Marco , Soussi Asma , Mapelli Francesca , Blilou Ikram , Borin Sara , Boudabous Abdellatif , Cherif Ameur , Daffonchio Daniele , Ouzari Hadda 
Published: June 2015

SummaryOases are desert‐farming agro‐ecosystems, where date palm (Phoenix dactylifera L.) plays a keystone role in offsetting the effects of drought and maintaining a suitable microclimate for agriculture. At present, abundance, diversity and plant growth promotion (PGP) of date palm root‐associated bacteria remain unknown. Considering the environmental pressure determined by the water scarcity in the desert environments, we hypothesized that bacteria associated with date palm roots improve plant resistance to drought. Here, the ecology of date palm root endophytes from oases in the Tunisian Sahara was studied with emphasis on their capacity to promote growth under drought. Endophytic communities segregated along a north–south gradient in correlation with geo‐climatic parameters. Screening of 120 endophytes indicated that date palm roots select for bacteria with multiple PGP traits. Bacteria rapidly cross‐colonized the root tissues of different species of plants, including the original Tunisian date palm cultivar, Saudi Arabian cultivars and Arabidopsis. Selected endophytes significantly increased the biomass of date palms exposed to repeated drought stress periods during a 9‐month greenhouse experiment. Overall, results indicate that date palm roots shape endophytic communities that are capable to promote plant growth under drought conditions, thereby contributing an essential ecological service to the entire oasis ecosystem.
The worldwide distribution of genetically and phylogenetically diverse Bacillus cereus isolates harbouring Bacillus anthracis‐like plasmids
Authors: Kaminska Paulina Sylwia , Yernazarova Aliya , Drewnowska Justyna Malgorzata , Zambrowski Grzegorz , Swiecicka Izabela 
Published: June 2015

SummaryBacillus cereus is a close relative of B. anthracis, the causative agent of anthrax whose pathogenic determinants are located on pXO1 and pXO2 plasmids. Bacillus anthracis‐like plasmids have been also noted among B. cereus, however, genetic features of B. cereus harbouring these elements remain largely undescribed, especially from the global perspective. Herein, we present the genetic polymorphism, population structure and phylogeny of B. cereus with pXO1‐/pXO2‐like plasmids originating from Argentina, Kazakhstan, Kenya and Poland. The plasmids were found in about 17% of the isolates, but their frequencies and expression of replicons differed within and between populations. In the multi‐locus sequence typing, the bacteria exhibited high genetic polymorphism reflected by 116 sequencing types, including 84 singletons and 10 clonal complexes, which mainly consisted of isolates of the same origin. The phylogenetic analysis of pXO1‐/pXO2‐like positive B. cereus isolates revealed six independent clades; in certain clades individual populations predominated. Generally, B. cereus with pXO1‐/pXO2‐like plasmids did not indicate the genetic relationship with B. anthracis, and cannot be classified into an evolutionary independent anthrax line within the B. cereus group. Our report is of a crucial importance for discovering the genetic specificity and evolution of B. cereus bacilli.
Stable isotope ratios of hydrogen separate mammals of aquatic and terrestrial food webs
Authors: Voigt Christian C. , Lehmann David , Greif Stefan 
Published: June 2015

Summary

In food web studies, hydrogen stable isotope ratios (δ2H) are increasingly used as endogenous markers to quantify the relative importance of allochthonous input of organic material into aquatic ecosystems. Yet, it is unclear if differences in δ2H values between aquatic and terrestrial food webs translate into corresponding differences of δ2H values of vertebrate consumers.

Using a triple‐isotope approach, we asked if fur keratin of 12 sympatric, non‐migratory bat species differ in stable isotope ratios (δ2HK, δ13CK, δ15NK) according to the ecosystem (aquatic or terrestrial) in which they predominantly forage. We conducted a study with two captive species beforehand that suggested species‐specific differences in trophic discrimination for C and N, but not for H.

In wild bats, stable isotope ratios of two Myotis species that trawl insects in aquatic habitats differed from those of four congeneric species that glean terrestrial insects by about 40‰ for H and by about 5‰ for N, indicating that both δ2HK and δ15NK values are useful for identifying membership of aquatic and terrestrial food webs. Further, we assessed the relative association of aerial‐hawking bat species to the terrestrial food web using trawling and gleaning bats as representatives of consumers in aquatic and terrestrial ecosystems, respectively. We found that the relative association of bats to terrestrial food webs varied largely among species, ranging from about 90% in Rhinolophus hipposideros to 43% in Eptesicus serotinus. Isotopic niche dimensions, as estimated by standardized ellipse areas using δ2HK and δ15NK values, varied largely among the 12 study species, with largest overlaps of isotopic niches among members of the aerial‐hawking bat ensemble.

We conclude that δ2HK and δ15NK values are suitable parameters for evaluating the relative membership of mammals to aquatic and terrestrial food webs and also to evaluate isotopic niche dimensions and thus niche packing of species within consumer ensembles.
The Ordinary Envy of Aguabuena People: Revisiting Universalistic Ideas from Local Entanglements
Authors: Castellanos Daniela 
Published: June 2015

SummaryEnvy encompasses various forms of relatedness among Aguabuena people, a small potter community of rural Andean Colombia. Drawing from ethnographic material, this article explores how envy is reciprocated in three concrete scenarios (kinship, legal sues, and hydraulics), arguing for an understanding centered in envy's ordinariness and daily practices as an analytical context from where to revisit more universalistic ideas.
“Everything Got Kinda Strange after a While:” Some Reflections on Translating Navajo Poetry that Should not be Translated
Authors: Webster Anthony K. 
Published: June 2015

SummaryInspired by an inquiry from a Navajo friend about why I had not published on a particular poem by Rex Lee Jim, this paper engages that question through three interconnected themes. First, there will be an analysis of the poem by Jim where I translate the poem but also place it within the context of Navajo concerns with k'é (reciprocity, generosity). Second, I turn to thinking through some of the issues brought out in the translation of the Navajo word ajik'eed as “one fucks.” This leads to questions about the ways that indigenous languages and their speakers are imagined and represented. Finally, I take up the foregoing issues as I reflect on my own translation practices.
Synergistic intracellular iron chelation combinations: mechanisms and conditions for optimizing iron mobilization
Authors: Vlachodimitropoulou Koumoutsea Evangelia , Garbowski Maciej , Porter John 
Published: June 2015

SummaryIron chelators are increasingly combined clinically but the optimal conditions for cellular iron mobilization and mechanisms of interaction are unclear. Speciation plots for iron(III) binding of paired combinations of the licensed iron chelators desferrioxamine (DFO), deferiprone (DFP) and deferasirox (DFX) suggest conditions under which chelators can combine as ‘shuttle’ and ‘sink’ molecules but this approach does not consider their relative access and interaction with cellular iron pools. To address this issue, a sensitive ferrozine‐based detection system for intracellular iron removal from the human hepatocyte cell line (HuH‐7) was developed. Antagonism, synergism or additivity with paired chelator combinations was distinguished using mathematical isobologram analysis over clinically relevant chelator concentrations. All combinations showed synergistic iron mobilization at 8 h with clinically achievable concentrations of sink and shuttle chelators. Greatest synergism was achieved by combining DFP with DFX, where about 60% of mobilized iron was attributable to synergistic interaction. These findings predict that the DFX dose required for a half‐maximum effect can be reduced by 3·8‐fold when only 1 μmol/l DFP is added. Mechanisms for the synergy are suggested by consideration of the iron‐chelate speciation plots together with the size, charge and lipid solubilities for each chelator. Hydroxypyridinones with low lipid solubilities but otherwise similar properties to DFP were used to interrogate the mechanistic interactions of chelator pairs. These studies confirm that synergistic cellular iron mobilization requires one chelator to have the physicochemical properties to enter cells, chelate intracellular iron and subsequently donate iron to a second ‘sink’ chelator.
Susceptibility to 6‐MP toxicity conferred by a NUDT15 variant in Japanese children with acute lymphoblastic leukaemia
Authors: Tanaka Yoichi , Kato Motohiro , Hasegawa Daisuke , Urayama Kevin Y. , Nakadate Hisaya , Kondoh Kensuke , Nakamura Kozue , Koh Katsuyoshi , Komiyama Takako , Manabe Atsushi 
Published: June 2015

SummaryGenotyping of TPMT prior to 6‐mercaptopurine (6‐MP) administration in acute lymphoblastic leukaemia (ALL) patients has been integrated into clinical practice in some populations of European ancestry. However, the comparable rates of 6‐MP myelotoxicity, but rarity of TPMT variants, in Asians suggest that major determinants have yet to be discovered in this population. We genotyped 92 Japanese paediatric ALL patients for NUDT15 rs116855232, a 6‐MP toxicity‐related locus discovered in Asians. Logistic regression and survival analysis were used to evaluate its association with leucopenia, hepatotoxicity, 6‐MP dose reduction, therapy interruption and event‐free survival. The allele frequency of rs116855232 was 0·16, and leucopenia was more common in carriers of the T allele (odds ratio, 7·20; 95% confidence interval, 2·49–20·80; P = 2·7 × 10−4). As leucopenia results in 6‐MP dose reduction, we observed average doses during maintenance therapy of 40·7, 29·3 and 8·8 mg/m2 for patients with CC, CT and TT genotypes, respectively (P < 0·001). Hepatotoxicity was observed only in CC genotype patients. Event‐free survival did not significantly differ by NUDT15 genotype. rs116855232 is an important determinant of 6‐MP myelotoxicity in Japanese children with ALL and may represent the most robust toxicity‐related locus in Asians to date. Considerations for clinical application may be warranted.
The Value of Quality Improvement Process in the Detection and Correction of Common Errors in Echocardiographic Hemodynamic Parameters in a Busy Echocardiography Laboratory
Authors: Fanari Zaher , Choudhry Usman I. , Reddy Vivek K. , Eze‐Nliam Chete , Hammami Sumaya , Kolm Paul , Weintraub William S. , Marshall Erik S. 
Published: June 2015

BackgroundAccurate assessment of cardiac structures, ventricular function, and hemodynamics is essential for any echocardiographic laboratory. Quality improvement (QI) processes described by the American Society of Echocardiography (ASE) and the Intersocietal Commission (IAC) should be instrumental in reaching this goal.MethodsAll patients undergoing transthoracic echocardiogram (TTE) followed by cardiac catheterization within 24 hours at Christiana Care Health System in 2011 and 2012 were identified, with 126 and 133 cases, respectively. Hemodynamic parameters of diastolic function and pulmonary artery systolic pressure (PASP) on TTE correlated poorly with catheterization in 2011. An educational process was developed and implemented at quarterly QI meetings based on ASE and IAC recommendations to target frequently encountered errors and provide methods for improved performance. The hemodynamic parameters were then reexamined in 2012 postintervention.ResultsFollowing the QI process, there was significant improvement in the correlation between invasive and echocardiographic hemodynamic measurements in both systolic and diastolic function, and PASP. This reflected in significant better correlations between echo and cath LVEF [R = 0.88, ICC = 0.87 vs. R = 0.85, ICC = 0.85; P < 0.001], average E/E′ and of left ventricle end‐diastolic pressure (LVEDP) [R = 0.62 vs. R = 0.09, P = 0.006] and a better correlation for PASP [R = 0.77, ICC = 0.77 vs. R = 0.30, ICC = 0.31; P = 0.05] in 2012 compared to 2011.ConclusionThe QI process, as recommended by ASE and IAC, can allow for identification as well as rectification of quality issues in a large regional academic medical center hospital.
Cardiac resynchronization therapy and cardiac sympathetic function
Authors: Martignani Cristian , Diemberger Igor , Nanni Cristina , Biffi Mauro , Ziacchi Matteo , Boschi Stefano , Corzani Alessandro , Fanti Stefano , Sambuceti Gianmario , Boriani Giuseppe 
Published: June 2015

AbstractBackgroundCardiac resynchronization therapy (CRT) is an established therapy for advanced congestive heart failure, improving both survival and hospitalization. The mechanism beneath these improvements still needs to be defined as about one‐third of the patients do not benefit from resynchronization. Restoration of sympatho‐vagal function can play a significant role in the process, but available data are limited. In this scenario, positron emission tomography scans with 11C‐hydroxyephedrine, a noradrenaline analogous, has the potential to characterize the modifications of the sympathetic nervous system induced by CRT in decompensated patients.Materials and methodsTen patients (six males, age 68 ± 10 years) with primary dilated cardiomyopathy were studied before and after resynchronization (acutely and after 3 months), from a clinical and echocardiographic point of view. Their cardiac sympathetic nerve activity was evaluated by 11C‐hydroxyephedrine positron emission tomography before resynchronization, at short and medium term after resynchronization.ResultsResponders to CRT (patients showing ≥ 15% decrease in left ventricular end‐systolic volume) showed a higher level of left ventricular radiotracer uptake both at baseline and after resynchronization with respect to nonresponders. This was coupled with a progressive improvement in homogeneity in left ventricular tracer uptake mainly in responders.ConclusionsCardiac resynchronization therapy improves cardiac sympathetic nerve activity in responders since its activation, while nonresponders do not show any significant change at any time of evaluation. CRT seems to be more effective in those patients with a still structurally preserved, yet functionally impaired, neuroautonomic system.
Concentration‐dependent activation of dopamine receptors differentially modulates GABA release onto orexin neurons
Authors: Linehan Victoria , Trask Robert B. , Briggs Chantalle , Rowe Todd M. , Hirasawa Michiru 
Published: June 2015

AbstractDopamine (DA) and orexin neurons play important roles in reward and food intake. There are anatomical and functional connections between these two cell groups: orexin peptides stimulate DA neurons in the ventral tegmental area and DA inhibits orexin neurons in the hypothalamus. However, the cellular mechanisms underlying the action of DA on orexin neurons remain incompletely understood. Therefore, the effect of DA on inhibitory transmission to orexin neurons was investigated in rat brain slices using the whole‐cell patch‐clamp technique. We found that DA modulated the frequency of spontaneous and miniature IPSCs (mIPSCs) in a concentration‐dependent bidirectional manner. Low (1 μm) and high (100 μm) concentrations of DA decreased and increased IPSC frequency, respectively. These effects did not accompany a change in mIPSC amplitude and persisted in the presence of G‐protein signaling inhibitor GDPβS in the pipette, suggesting that DA acts presynaptically. The decrease in mIPSC frequency was mediated by D2 receptors whereas the increase required co‐activation of D1 and D2 receptors and subsequent activation of phospholipase C. In summary, our results suggest that DA has complex effects on GABAergic transmission to orexin neurons, involving cooperation of multiple receptor subtypes. The direction of dopaminergic influence on orexin neurons is dependent on the level of DA in the hypothalamus. At low levels DA disinhibits orexin neurons whereas at high levels it facilitates GABA release, which may act as negative feedback to curb the excitatory orexinergic output to DA neurons. These mechanisms may have implications for consummatory and motivated behaviours.
Tumor necrosis factor enhances the sleep‐like state and electrical stimulation induces a wake‐like state in co‐cultures of neurons and glia
Authors: Jewett Kathryn A. , Taishi Ping , Sengupta Parijat , Roy Sandip , Davis Christopher J. , Krueger James M. 
Published: June 2015

AbstractWe characterise sleep‐like states in cultured neurons and glia during development in vitro as well as after electrical stimulation, the addition of tumor necrosis factor alpha (TNF), and the combination of TNF plus electrical stimulation. We also characterise optogenetic stimulation‐induced ATP release and neuronal interleukin‐1 and TNF expression in vitro demonstrating the activity dependence of these putative sleep‐regulatory substances. Action potential (AP) burstiness, expressed as the burstiness index (BI), synchronization of slow electrical potentials between recording electrodes (SYN), and slow wave (SW) power (0.25–3.75 Hz) determined using fast Fourier analyses emerged as network properties, maturing after 2 weeks in culture. Homologous in vivo measures are used to characterise sleep. Electrical stimulation reduced the BI, SYN and SW power values during and/or after the stimulus period. One day later, homeostasis was evident from rebounds of SYN and SW power values to above baseline levels; the magnitude of the rebound was stimulus pattern‐dependent. The addition of TNF enhanced BI, SYN and SW power values, suggesting the induction of a deeper sleep‐like state. Electrical stimulation reversed these TNF effects, suggesting the network state was more wake‐like. The day after TNF plus electrical stimulation, the changes in SYN and SW power values were dependent upon the stimulus patterns the cells received the day before. We conclude that sleep and wake states in cultured in vitro networks can be controlled and they share molecular regulatory mechanisms with local in vivo networks. Further, sleep is an activity‐dependent emergent local network property.
Topological organization of CA3‐to‐CA1 excitation
Authors: Hongo Yoshie , Ogawa Koichi , Takahara Yuji , Takasu Keiko , Royer Sebastien , Hasegawa Minoru , Sakaguchi Gaku , Ikegaya Yuji 
Published: June 2015

AbstractThe CA1‐projecting axons of CA3 pyramidal cells, called Schaffer collaterals, constitute one of the major information flow routes in the hippocampal formation. Recent anatomical studies have revealed the non‐random structural connectivity between CA3 and CA1, but little is known regarding the functional connectivity (i.e. how CA3 network activity is functionally transmitted downstream to the CA1 network). Using functional multi‐neuron calcium imaging of rat hippocampal slices, we monitored the spatiotemporal patterns of spontaneous CA3 and CA1 burst activity under pharmacological GABAergic blockade. We found that spatially clustered CA3 activity patterns were transformed into layered CA1 activity sequences. Specifically, synchronized bursts initiated from multiple hot spots in CA3 ensembles, and CA1 neurons located deeper in the pyramidal cell layer were recruited during earlier phases of the burst events. The order of these sequential activations was maintained across the bursts, but the sequence velocity varied depending on the inter‐burst intervals. Thus, CA3 axons innervate CA1 neurons in a highly topographical fashion.
A Duty‐Free Europe? What's Wrong with Kochenov's Account of EU Citizenship Rights
Authors: Bellamy Richard 
Published: June 2015

AbstractThis article disputes the recent argument of Dimitry Kochenov advocating an ‘EU Citizenship without Duties’. His thesis rests on an untenable form of philosophical anarchism that overlooks the role played by our political obligations to state structures in securing rights. At best, his argument suggests a ‘thin’ form of EU citizenship that allows European citizens to choose which of the Member States they wish to become morally obliged to. A ‘thicker’ form of EU level citizenship could only arise by creating civic obligations at the EU level, the position he rejects. To the extent certain Court of Justice judgments in this area reflect parallel reasoning to Kochenov's, they too suffer from a similar failure to appreciate the role of civic duties to particular Member States (or, eventually, the EU) in creating and securing the status of citizens as equal rights bearers.