bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multivariate analysis of the population systematics of the ringed snake, Natrix natrix (L)
Authors: Thorpe R. S. 
Published: March 2014

SynopsisThe racial affinities of the widely distributed (palearctic) ringed snake, Natrix natrix were assessed using a large number of phenotypic characters from a wide range of features. These characters show a considerable amount of complex geographic variation which is further complicated by geographic variation in the extent of their sexual, ontogenetic and local variation. Nevertheless, extensive analysis of the data using univariate statistics, numerical taxonomy and a wide range of multivariate statistics allowed the primary patterns of ‘racial’ differentiation to be elucidated.The dominant feature of the racial affinities is the division of the majority of the complex into distinct eastern and western forms which meet along a ‘hybrid zone’. The nature of this zone is analysed in detail and discussed in relation to aspects of evolutionary theory such as gene flow. The island populations of Corsica and Sardinia are also extremely divergent. The evolution and taxonomy of the four primary subdivisions of the complex (east, west, Corsica, Sardinia) are discussed in relation to Pleistocene history, evolutionary theory, species concepts (phenetic and biological) and subspecies concepts, etc. These four subdivisions border on the species rank and may be regarded by some as semispecies. They are formally recognised as subspecies. Attention is drawn to the difficulties of intraspecific taxonomy and the arbitrary nature of the four taxa given formal recognition.
mGlu5 receptors and cellular prion protein mediate amyloid-β-facilitated synaptic long-term depression in vivo
Authors: Hu Neng-Wei , Nicoll Andrew J. , Zhang Dainan , Mably Alexandra J. , O’Malley Tiernan , Purro Silvia A. , Terry Cassandra , Collinge John , Walsh Dominic M. , Rowan Michael J. 
Published: March 2014

AbstractNMDA-type glutamate receptors (NMDARs) are currently regarded as paramount in the potent and selective disruption of synaptic plasticity by Alzheimer’s disease amyloid β-protein (Aβ). Non-NMDAR mechanisms remain relatively unexplored. Here we describe how Aβ facilitates NMDAR-independent long-term depression of synaptic transmission in the hippocampus in vivo. Synthetic Aβ and Aβ in soluble extracts of Alzheimer’s disease brain usurp endogenous acetylcholine muscarinic receptor-dependent long-term depression, to enable long-term depression that required metabotropic glutamate-5 receptors (mGlu5Rs). We also find that mGlu5Rs are essential for Aβ-mediated inhibition of NMDAR-dependent long-term potentiation in vivo. Blocking Aβ binding to cellular prion protein with antibodies prevents the facilitation of long-term depression. Our findings uncover an overarching role for Aβ-PrPC-mGlu5R interplay in mediating both LTD facilitation and LTP inhibition, encompassing NMDAR-mediated processes that were previously considered primary.
microRNA input into a neural ultradian oscillator controls emergence and timing of alternative cell states
Authors: Goodfellow Marc , Phillips Nicholas E. , Manning Cerys , Galla Tobias , Papalopulu Nancy 
Published: March 2014

AbstractProgenitor maintenance, timed differentiation and the potential to enter quiescence are three fundamental processes that underlie the development of any organ system. In the nervous system, progenitor cells show short-period oscillations in the expression of the transcriptional repressor Hes1, while neurons and quiescent progenitors show stable low and high levels of Hes1, respectively. Here we use experimental data to develop a mathematical model of the double-negative interaction between Hes1 and a microRNA, miR-9, with the aim of understanding how cells transition from one state to another. We show that the input of miR-9 into the Hes1 oscillator tunes its oscillatory dynamics, and endows the system with bistability and the ability to measure time to differentiation. Our results suggest that a relatively simple and widespread network of cross-repressive interactions provides a unifying framework for progenitor maintenance, the timing of differentiation and the emergence of alternative cell states.
Assessing Plural Morphology in Children Acquiring /S/-Leniting Dialects of Spanish
Authors: Miller Karen 
Published: March 2014

Purpose
To examine the production of plural morphology in children acquiring a dialect of Spanish with syllable-final /s/ lenition with the goal of comparing how plural marker omissions in the speech of these children compare with plural marker omissions in children with language impairment acquiring other varieties of Spanish.

Method
Three production tasks were administered to children. A repetition task was used to examine children's production of the plural marker in plural noun phrases, and 2 Berko-style tasks evaluated children's production of the plural marker in bare nouns. Behavior on these tasks was compared with plural marker comprehension for each individual child.

Results
There was a correlation between children's comprehension of the plural marker and their production of the plural marker on plural noun phrases in the repetition task but not between comprehension and production of the plural marker on bare nouns in the Berko-style tasks.

Conclusions
Assessments of plural morphology as a clinical marker of language impairment in Spanish-speaking children may be problematic, especially in children acquiring dialects of Spanish with /s/ lenition, such as those originating in Chile, the Dominican Republic, Cuba, Puerto Rico, and Central America. Instead, for children acquiring /s/-leniting dialects of Spanish, assessments of the plural marker in noun phrases produced within a sentence frame may be a better indicator of acquisition than traditional Berko-style tasks that elicit bare nouns.
One-Stage Biopsy, Debridement, Reconstruction, and Stabilization of Pyogenic Vertebral Osteomyelitis
Authors: Menon Venugopal K. , Kumar Kishore M. , Al Ghafri Khalifa 
Published: March 2014

Study Design Retrospective cohort study. Objective To evaluate whether the proposed one-stage biopsy, culture, debridement, and reconstruction with stabilization strategy is a viable option for pyogenic vertebral osteomyelitis (PVO). PVO is increasing in frequency globally, particularly in immunologically compromised individuals. Typically, biopsy and culture sensitivity followed by staged surgery and long-term antibiotic therapy is the mainstay of therapy. Methods This is a study of a group of 32 consecutive cases of PVO (spondylodiskitis) treated in our institution from 2010 to 2012. All cases had one-stage biopsy, culture sensitivity, debridement, reconstruction with iliac bone graft, and stabilization with titanium implants. The mean age in this series was 51 years, and the male-to-female ratio was 2.2:1. Approximately 50% of the patients had impaired immunity status. The commonest organism isolated was Pseudomonas aeruginosa. Culture-specific antibiotics were given for a minimum of 6 weeks to all patients. The follow-up period ranged from 6 months to a maximum of 2 years. All patients were assessed for wound healing, recurrence of infection, deformity progression, pain, and healing by radiologic and biochemical parameters. No generic or disease-specific outcome tools were used for this study. Results All patients had good wound healing, although there was one case of superficial infection that was resolved with debridement. There were two implant failures with pseudarthrosis and one localized kyphosis in this series. Conclusions The one-stage technique of biopsy, debridement, bone grafting, and stabilization can be recommended for most cases of PVO.
Principles of scientific research team formation and evolution
Authors: Milojević Staša 
Published: March 2014

SignificanceScience is an activity with far-reaching implications for modern society. Understanding how the social organization of science and its fundamental unit, the research team, forms and evolves is therefore of critical significance. Previous studies uncovered important properties of the internal structure of teams, but little attention has been paid to their most basic property: size. This study fills this gap by presenting a model that successfully explains how team sizes in various fields have evolved over the past half century. This model is based on two principles: (i) smaller (core) teams form according to a Poisson process, and (ii) larger (extended) teams begin as core teams but consequently accumulate new members through the process of cumulative advantage based on productivity.
Tumor suppressor role of phospholipase Cε in Ras-triggered cancers
Authors: Martins Marta , McCarthy Afshan , Baxendale Rhona , Guichard Sabrina , Magno Lorenza , Kessaris Nicoletta , El-Bahrawy Mona , Yu Philipp , Katan Matilda 
Published: March 2014

SignificanceRas oncogens have been implicated in high proportion of cancers. However, selective treatment for Ras oncogenes is not yet available and components that could mediate Ras functions are being extensively assessed as alternative targets. For some potential targets, such as phospholipase Cε (PLCε), it is not clear how they contribute to tumor development. Here we provide several lines of experimental evidence that support a tumor suppressor function of PLCε, contrasting a positive role of several other well-defined effectors of Ras. Our results show a tumor suppressor role for this PLC in animal models and describe its impact on cell proliferation. Together with observations of marked down-regulation in several types of tumors, this study suggests its use as a biological marker in cancer.
Increasing homogeneity in global food supplies and the implications for food security
Authors: Khoury Colin K. , Bjorkman Anne D. , Dempewolf Hannes , Ramirez-Villegas Julian , Guarino Luigi , Jarvis Andy , Rieseberg Loren H. , Struik Paul C. 
Published: March 2014

Significance
This study provides evidence of change in the relative importance of different crop plants in national food supplies worldwide over the past 50 years. Within a global trend of increased overall quantities of food calories, protein, fat, and weight, and increased proportions of those quantities sourcing from energy-dense foods, national food supplies diversified in regard to contributing measured crop commodities. As a consequence, national food supplies globally have become increasingly similar in composition, based upon a suite of truly global crop plants. The growth in reliance worldwide on these crops heightens interdependence among countries in their food supplies, plant genetic resources, and nutritional priorities.
Categorical encoding of color in the brain
Authors: Bird Chris M. , Berens Samuel C. , Horner Aidan J. , Franklin Anna 
Published: March 2014

SignificanceHumans group the millions of discriminable colors into discrete categories, such as “blue” and “green.” There has been much debate about where color categories come from; for example, whether color categories are inbuilt into the visual system. We use functional MRI to identify regions of the brain that categorize color. Color categories are encoded by regions of the frontal lobes, which also categorize other information (e.g., sounds). Interestingly, the visual cortex responds only to the size of color differences, but not color categories. We conclude that color categories occur at the level of attention rather than being inbuilt into the visual system. The findings shed light on how the brain categorizes information and how it processes color.
Myosin lever arm directs collective motion on cellular actin network
Authors: Hariadi Rizal F. , Cale Mario , Sivaramakrishnan Sivaraj 
Published: March 2014

Significance
Myosins function as groups of motors anchored to a cellular scaffold that interacts with neighboring actin filaments patterned in complex three-dimensional networks. Although much is known about the function of individual myosin molecules, the contribution of intermotor interactions to collective movement is poorly understood. We used a precisely engineered biomimetic system to investigate how the mechanics of a structural element in the individual myosin influences the collective motion of groups of motors. Stochastic simulations suggest that the interplay between intramolecular strain on the motor lever arm and intermotor tension dictates trajectory shapes in groups of identical and antagonistic motors. Our study provides a general approach to dissecting emergence in cellular processes with applications for the efficient synthetic design of molecular transport systems.
Molecular interferometer to decode attosecond electron–nuclear dynamics
Authors: Palacios Alicia , González-Castrillo Alberto , Martín Fernando 
Published: March 2014

Significance
Current attosecond technologies designed to study fast electron and nuclear motion in molecules make use, at some stage, of infrared laser pulses that strongly perturb the molecular potential, thus modifying the dynamics inherent to the system. To access the actual dynamics of the molecule, gentler laser sources must be used. Very recently, extreme UV pulses have been successfully combined to provide a picture of the intrinsic electron dynamics in atoms with subfemtosecond time resolution. Here we show that by using two identical extreme UV pulses, one can also obtain a complete description of the coupled electronic and nuclear dynamics in molecules. Visualization of such dynamics is possible by varying the wavelength and/or the time delay between the two pulses.
Quantifying the atomic-level mechanics of single long physisorbed molecular chains
Authors: Kawai Shigeki , Koch Matthias , Gnecco Enrico , Sadeghi Ali , Pawlak Rémy , Glatzel Thilo , Schwarz Jutta , Goedecker Stefan , Hecht Stefan , Baratoff Alexis , Grill Leonhard , Meyer Ernst 
Published: March 2014

Significance
Mechanical properties of biopolymers such as DNA and proteins have been studied to understand the details of complex processes in living systems via systematic statistical analyses of repeated measurements. However, the mechanical behavior of a single molecular chain pulled off a surface has never been investigated with atomic-scale resolution. Herein, we present such a study on in situ polymerized fluorene chains by pulling individual chains with the tip of an atomic force microscope at 4.8 K. The measured variations of the force gradient provide detailed insights into the detachment process of fluorene units and the role of near-incommensurability with the substrate structure.
Memory loss in a nonnavigational spatial task after hippocampal inactivation in monkeys
Authors: Forcelli Patrick A. , Palchik Guillermo , Leath Taylor , DesJardin Jacqueline T. , Gale Karen , Malkova Ludise 
Published: March 2014

SignificanceAlthough the hippocampus has a well-documented role for spatial navigation across species, its role for spatial memory in nonnavigational tasks is uncertain. Thus, when monkeys are tested in tasks that do not require navigation through space, spatial memory seems unaffected by hippocampal lesions. However, the interpretation of these results is compromised by long-term compensatory adaptation occurring in the days and weeks after lesions. To preclude long-term compensation, we transiently inactivated hippocampus at the time of testing. Hippocampal inactivation reduced performance on a nonnavigational spatial memory task to chance levels. These data align the role of hippocampus for spatial memory in monkeys with the broader literature while simultaneously demonstrating the efficacy of inactivation of hippocampus in monkeys.
Circulating hematopoietic stem and progenitor cells are myeloid-biased in cancer patients
Authors: Wu Wen-Chao , Sun Hong-Wei , Chen Hai-Tian , Liang Jing , Yu Xing-Juan , Wu Chong , Wang Zilian , Zheng Limin 
Published: March 2014

Significance
Hematopoietic stem and progenitor cells (HSPCs) cannot only replace depleted progeny pools, but act as the primary immune response to various pathological conditions. Here we show that the circulating HSPCs from various patients with solid tumors exhibit a generalized myeloid bias with a skew toward granulocytic differentiation. Importantly, circulating hematopoietic precursors were highly enriched in tumor tissues and positively correlated with disease progression. We developed an in vitro short-term culture model to effectively induce the rapid generation of myeloid-derived suppressor cells (MDSCs), defined as cord blood-derived MDSCs. In addition, we suggest that the altered circulating HSPCs may serve as an important link between dysregulated hematopoiesis and accumulated immunosuppressive MDSCs in patients with cancer.
Contextual effect of positive intergroup contact on outgroup prejudice
Authors: Christ Oliver , Schmid Katharina , Lolliot Simon , Swart Hermann , Stolle Dietlind , Tausch Nicole , Al Ramiah Ananthi , Wagner Ulrich , Vertovec Steven , Hewstone Miles 
Published: March 2014

Significance
Although mixed social environments can provoke conflict, where this diversity promotes positive intergroup contact, prejudice is reduced. Seven multilevel studies demonstrate that the benefits of intergroup contact are broader than previously thought. Contact not only changes attitudes for individuals experiencing direct positive intergroup contact, their attitudes are also influenced by the behavior (and norms) of fellow ingroup members in their social context. Even individuals experiencing no direct, face-to-face intergroup contact can benefit from living in mixed settings where fellow ingroup members do engage in such contact. Two longitudinal studies rule out selection bias as an explanation for these findings on the contextual level. Prejudice is a function not only of whom you interact with, but also of where you live.
Structural basis for gating mechanisms of a eukaryotic P-glycoprotein homolog
Authors: Kodan Atsushi , Yamaguchi Tomohiro , Nakatsu Toru , Sakiyama Keita , Hipolito Christopher J. , Fujioka Akane , Hirokane Ryo , Ikeguchi Keiji , Watanabe Bunta , Hiratake Jun , Kimura Yasuhisa , Suga Hiroaki , Ueda Kazumitsu , Kato Hiroaki 
Published: March 2014

Significance
P-glycoprotein exports various hydrophobic chemicals in an ATP-dependent manner, determines their absorption and distribution in the body, and is involved in multidrug resistance (MDR) in tumors. Understanding the mechanism of the multidrug transport is important for designing drugs of good bioavailability and efficient cancer chemotherapy. We determined the high-resolution crystal structures of a eukaryotic P-glycoprotein homolog and revealed the detailed architecture of its transmembrane domains, which contain an exit gate for substrates that opens to the extracellular side and two entrance gates that open to the intramembranous region and the cytosolic side. We propose a motion of the transmembrane domains powered by the association of two nucleotide-binding domains on ATP binding that is different from other transporters.
Fine mapping of genome activation in bovine embryos by RNA sequencing
Authors: Graf Alexander , Krebs Stefan , Zakhartchenko Valeri , Schwalb Björn , Blum Helmut , Wolf Eckhard 
Published: March 2014

Significance
Gene expression profiling is widely used to get insight into mechanisms of early embryonic development and to characterize embryos generated by various techniques or exposed to different culture conditions. Transcripts in early embryos may be of maternal or embryonic origin, which is difficult to distinguish by conventional techniques. RNA sequencing in bovine oocytes and embryos facilitated mapping of the onset of embryonic expression for almost 7,400 genes. The timing of embryonic gen(om)e activation offers an additional level of information for embryo biosystems research and for detecting disturbances of early development due to genetic, epigenetic, and environmental factors.
Small molecule probes to quantify the functional fraction of a specific protein in a cell with minimal folding equilibrium shifts
Authors: Liu Yu , Tan Yun Lei , Zhang Xin , Bhabha Gira , Ekiert Damian C. , Genereux Joseph C. , Cho Younhee , Kipnis Yakov , Bjelic Sinisa , Baker David , Kelly Jeffery W. 
Published: March 2014

Significance
Historically, the folding of individual proteins in buffers has been studied spectroscopically. The majority of spectroscopic methods (NMR and fluorescence excluded) cannot be used in a cell, because the protein of interest (POI) cannot be distinguished from the background proteome. Herein, we introduce folding probes, which when used in cell lysates with sufficient holdase activity, faithfully quantify the folded and functional fraction of a POI at a time point of interest in a cell by selectively reacting with that state to afford a fluorescent signal. This work provides a blueprint for how to convert enzyme inhibitors, ligands for nonenzyme proteins, etc. into folding probes to efficiently and specifically investigate how intracellular function is controlled by the proteostasis network as a function of cellular perturbations.
BMP signaling is required for the generation of primordial germ cells in an insect
Authors: Donoughe Seth , Nakamura Taro , Ewen-Campen Ben , Green Delbert A. , Henderson Lory , Extavour Cassandra G. 
Published: March 2014

Significance
Many model organisms specify germ cells using maternally supplied germ-line determinants. In contrast, mice rely on embryonic cell–cell signaling to induce cells to become germ cells. Molecular evidence for inductive germ-line specification had previously been provided only for the mouse. Here we provide functional evidence for inductive germ cell specification in an invertebrate, by showing that bone morphogenetic protein (BMP) signaling, which induces mouse germ cell specification, is required for establishment of embryonic germ cells in a cricket. BMP pathway knockdown causes reduction or loss of germ cells, and elevated levels of BMP signaling cause supernumerary and ectopic germ cells. BMP-based germ cell induction in mice and crickets suggests that this may be a shared ancestral mechanism in animals.
Fatty acid-inducible ANGPTL4 governs lipid metabolic response to exercise
Authors: Catoire Milène , Alex Sheril , Paraskevopulos Nicolas , Mattijssen Frits , Evers-van Gogh Inkie , Schaart Gert , Jeppesen Jacob , Kneppers Anita , Mensink Marco , Voshol Peter J. , Olivecrona Gunilla , Tan Nguan Soon , Hesselink Matthijs K. C. , Berbée Jimmy F. , Rensen Patrick C. N. , Kalkhoven Eric , Schrauwen Patrick , Kersten Sander 
Published: March 2014

Significance
Physical exercise causes profound changes in energy metabolism in humans. In this study we show that resting skeletal muscle has a crucial role in the metabolic response to acute exercise. During endurance exercise, selective induction of the protein angiopoietin-like 4 (ANGPTL4) in nonexercising muscle reduces local fatty acid uptake, presumably to prevent fat overload, while directing fatty acids to the active skeletal muscle as fuel. Our data thus suggest that nonexercising muscle has a key role in governing lipid homeostasis during exercise.
Amazonian functional diversity from forest canopy chemical assembly
Authors: Asner Gregory P. , Martin Roberta E. , Tupayachi Raul , Anderson Christopher B. , Sinca Felipe , Carranza-Jiménez Loreli , Martinez Paola 
Published: March 2014

Significance
Canopy trees are keystone organisms that create habitat for an enormous array of flora and fauna and dominate carbon storage in tropical forests. Determining the functional diversity of tree canopies is, therefore, critical to understanding how tropical forests are assembled and predicting ecosystem responses to environmental change. Across the megadiverse Andes-to-Amazon corridor of Peru, we discovered a large-scale nested pattern of canopy chemical assembly among thousands of trees. This nested geographic and phylogenetic pattern within and among forest communities provides a different perspective on current and future alterations to the functioning of western Amazonian forests resulting from land use and climate change.