bluuebunny/crossref_metadata_2025 huggingface dataset:
On friendship development and the Big Five personality traits
Authors: Harris Kelci , Vazire Simine
Published: November 2016

In this paper, we argue that friendship should receive more attention in social/personality research. Here, we focus on our area of expertise, personality traits, and review the literature on how personality traits influence friendship formation, maintenance, and dissolution. Specifically, we examine how personality traits of the actor and partner influence friendship development (i.e., who is more likely to initiate and end friendships, and who is more likely to be the target of friendship initiation and termination). We also discuss dyadic effects, such as personality similarity, on friendship development. Throughout this review, we draw on the literature on personality and romantic relationships to identify the most important gaps in the literature on personality and friendships. Our review suggests that agreeableness has the most consistent effects on both romantic relationships and friendships, followed by neuroticism. Extraversion, conscientiousness, and openness to experience have all been shown to influence relationship development, but their effects are inconsistent. We end with a call for more research on friendship beyond the role of personality traits and suggestions for specific future directions.
Daydreaming to navigate the social world: What we know, what we don't know, and why it matters
Authors: Poerio Giulia Lara , Smallwood Jonathan
Published: November 2016

A substantial portion of daily life is spent daydreaming—that is, engaged in thought independent of, and unrelated to, goals in the external environment. We argue that this naturally occurring, unconstrained cognition is a vital, but currently underappreciated, form of social cognition that enables navigation of the social world. First, we present the results of a meta‐analysis of neuroimaging studies which illustrate the shared neural basis of daydreaming and social cognition (including regions of the anterior temporal lobes and the posterior cingulate cortex). Second, we review evidence regarding the frequency, correlates, and adaptive outcomes of social daydreaming, cumulative findings that point to the adaptive value of imaging others during this offline state. We end by encouraging cross‐fertilization between daydreaming research and domains of social psychology (goal pursuit, social interactions, and close relationships), which we hope will foster mutually beneficial directions for understanding the role that unconstrained thinking plays in social life.
Identification of the novel HLA‐B*39:01:23 allele by polymerase chain reaction sequence‐based typing
Authors: He Y.‐M. , Dong L.‐N. , Chen N.‐Y. , He J. , Zhu F.‐M.
Published: November 2016

HLA‐B*39:01:23 differs from HLA‐B*39:01:01 by a single nucleotide substitution at position 153 C > T.
Reference data enhancement for geographic information retrieval using linked data
Authors: Moura Tiago H. V. M. , Davis Clodoveu A. , Fonseca Frederico T.
Published: November 2016

Gazetteers are instrumental in recognizing place names in documents such as Web pages, news, and social media messages. However, creating and maintaining gazetteers is still a complex task. Even though some online gazetteers provide rich sets of geographic names in planetary scale (e.g. GeoNames), other sources must be used to recognize references to urban locations, such as street names, neighborhood names or landmarks. We propose integrating Linked Data sources to create a gazetteer that combines a broad coverage of places with urban detail, including content on geographic and semantic relationships involving places, their multiple names and related non‐geographic entities. Our final goal is to expand the possibilities for recognizing, disambiguating and filtering references to places in texts for geographic information retrieval (GIR) and related applications. The resulting ontological gazetteer, named LoG (Linked OntoGazetteer), is accessible through Web services by applications and research initiatives on GIR, text processing, named entity recognition and others. The gazetteer currently contains over 13 million places, 140 million attributes and relationships, and 4.5 million non‐geographic entities. Data sources include GeoNames, Freebase, DBPedia and LinkedGeoData, which is based on OpenStreetMap data. An analysis on how these datasets overlap and complement one another is also presented.
Prevalence, incidence, and risk factors of human immunodeficiency virus infection in blood donors in the Southeastern United States
Authors: Crowder Lauren A. , Steele Whitney R. , Notari Edward P. , Hopkins Courtney K. , Lima Jose L.O. , Foster Gregory A. , Townsend Rebecca L. , Krysztof David E. , Dodd Roger Y. , Stramer Susan L.
Published: November 2016

BACKGROUND

Human immunodeficiency virus (HIV)‐positive blood donors pose a risk to blood safety. The Southeastern United States has the highest reported HIV infection rates. Here we calculate HIV prevalence, incidence, and residual risk in Southeastern US blood donors and report risk factors disclosed by incident donors in counseling sessions.

STUDY DESIGN AND METHODS

American Red Cross donation and testing data from 2009 to 2014 for three Southeastern collection regions were used to calculate HIV prevalence, incidence, and residual risk. Incident donors had a previous HIV‐negative donation within 730 days of their positive donation. Residual risk was defined as the window period multiplied by incidence.

RESULTS

From 2009 to 2014, a total of 236 HIV‐positive donors occurred in these regions for an overall prevalence of 8.3 per 100,000 donations. There were 56 incident donors over the 6‐year period with incidence decreasing from 7.1 per 100,000 person‐years (PYs) in the first two years (2009–2010) to 3.5 in the last two years (2013–2014). Residual risk decreased from 1 in 562,000 to 1 in 1,100,000. The most commonly reported risk factor behavior in male incident donors was men who have sex with men; females expressed no predominant risk factor.

CONCLUSION

HIV prevalence and incidence among blood donors in the southeast are higher than other US regions, consistent with general public health surveillance. However, the overall residual risk estimates are low at less than 1 per million. Ongoing monitoring of the blood supply along with educational efforts to provide infected individuals with alternatives to donation remain important initiatives.
A Jordanian family with three sisters apparently homozygous for Mk and evidence for clinical significance of antibodies produced by MkMk individuals
Authors: Al‐Jada Nour Al‐Huda
Published: November 2016

BACKGROUND

The rare MkMk phenotype is the result of a deletion of the coding regions of both GYPA and GYPB. Red blood cells (RBCs) of individuals homozygous for the rare Mk gene lack all MNS blood group antigens and have no glycophorin A or glycophorin B. This phenotype is extremely rare and only four families have been reported.

CASE REPORT

A 28‐year‐old woman was referred for assessment of recurrent early neonatal deaths. She was found to be apparently homozygous for Mk. With the presence of two MkMk sisters as matched donors, an intrauterine transfusion was performed to treat fetal anemia due to a strong maternal atypical antibody. Twins were delivered and subsequently transfused with RBCs from the proposita and her MkMk sisters.

CONCLUSION

This case reports the fifth family with members apparently homozygous for Mk and the second example of severe hemolytic disease of the fetus and newborn (HDFN) due to maternal antibodies produced by MkMk individuals. It also shows the importance of intensive monitoring and management of HDFN caused by alloantibodies to RBC antigens.
An association between ABO group and HLA antibody detection
Authors: Dunbar Nancy M. , Yazer Mark H. , Bravo Marjorie D. , Kamel Hany T. , Gorlin Jed , Norris Philip J. , Williamson Phillip C. , Vassallo Ralph R. ,   on behalf of the Biomedical Excellence for Safer Transfusion (BEST) Collaborative
Published: November 2016

BACKGROUND

US blood centers can screen female plateletpheresis donors with a history of one or more pregnancies for both Class I and Class II anti‐HLA antibodies using one of two platforms. One is a flow‐based assay that yields a quantitative result and the other an enzyme‐linked immunosorbent assay (ELISA) that yields either a positive or a negative result (above or below cutoff).

STUDY DESIGN AND METHODS

The results of HLA antibody screening tests were analyzed by donor ABO group. Results from large and small American blood collection centers using both platforms were analyzed. Positivity rates were compared by chi‐square test and the results stratified by parity using the Mann‐Whitney test.

RESULTS

No differences in parity were noted among donors of different ABO groups, but a significantly higher rate of HLA antibody positivity was observed among group O donors for the ELISA (31% of group O donors vs. 21% of non–group O donors, p < 0.0001). The higher rate of positivity was primarily due to Class I reactivity. This difference in antibody frequency was not observed at centers using the flow‐based assay.

CONCLUSION

Centers using the ELISA may have a higher rate of permanent deferral from plateletpheresis donation among group O female donors. Although the reasons for the higher rate of reactivity on Class I ELISA testing are unknown, this could result from test system characteristics or differences in group O donor antibody strength or specificity.
Warm hands, cold heart: progressive whole‐body cooling increases warm thermosensitivity of human hands and feet in a dose‐dependent fashion
Authors: Filingeri Davide , Morris Nathan B. , Jay Ollie
Published: November 2016

New Findings

What is the central question of this study?

Investigations on inhibitory/facilitatory modulation of vision, touch and pain show that conditioning stimuli outside the receptive field of testing stimuli modulate the central processing of visual, touch and painful stimuli. We asked whether contextual modulation also exists in human temperature integration.

What is the main finding and its importance?

Progressive decreases in whole‐body mean skin temperature (the conditioning stimulus) significantly increased local thermosensitivity to skin warming but not cooling (the testing stimuli) in a dose‐dependent fashion. In resembling the central mechanisms underlying endogenous analgesia, our findings point to the existence of an endogenous thermosensory system in humans that could modulate local skin thermal sensitivity to facilitate thermal behaviour.

Although inhibitory/facilitatory central modulation of vision and pain has been investigated, contextual modulation of skin temperature integration has not been explored. Hence, we tested whether progressive decreases in whole‐body mean skin temperature (Tsk; a large conditioning stimulus) alter the magnitude estimation of local warming and cooling stimuli applied to hairy and glabrous skin. On four separate occasions, eight men (27 ± 5 years old) underwent a 30 min whole‐body cooling protocol (water‐perfused suit; temperature, 5°C), during which a quantitative thermosensory test, consisting of reporting the perceived magnitude of warming and cooling stimuli (±8°C from 30°C baseline) applied to the hand (palm/dorsum) and foot (sole/dorsum), was performed before cooling and every 10 min thereafter. The cooling protocol resulted in large progressive reductions in Tsk [10 min, −3.36°C (95% confidence interval −2.62 to −4.10); 20 min, −5.21°C (−4.47 to −5.95); and 30 min, −6.32°C (−5.58 to −7.05); P < 0.001], with minimal changes (∼0.08°C) in rectal temperature. While thermosensitivity to local skin cooling remained unchanged (P = 0.831), sensitivity to skin warming increased significantly at each level of Tsk for all skin regions [10 min, +4.9% (−1.1 to +11.0); 20 min, +6.1% (+0.1–12.2); and 30 min, +7.9% (+1.9–13.9); P = 0.009]. Linear regression indicated a 1.2% °C−1 increase in warm thermosensitivity with whole‐body skin cooling. Overall, large decreases in Tsk significantly facilitated warm but not cold sensory processing of local thermal stimuli, in a dose‐dependent fashion. In highlighting a novel feature of human temperature integration, these findings point to the existence of an endogenous thermosensory system that could modulate local skin thermal sensitivity in relationship to whole‐body thermal states.
Adaptation of exercise‐induced stress in well‐trained healthy young men
Authors: JanssenDuijghuijsen Lonneke M. , Keijer Jaap , Mensink Marco , Lenaerts Kaatje , Ridder Lars , Nierkens Stefan , Kartaram Shirley W. , Verschuren Martie C. M. , Pieters Raymond H. H. , Bas Richard , Witkamp Renger F. , Wichers Harry J. , van Norren Klaske
Published: November 2016

New Findings

What is the central question of this study?

Exercise is known to induce stress‐related physiological responses, such as changes in intestinal barrier function. Our aim was to determine the test–retest repeatability of these responses in well‐trained individuals.

What is the main finding and its importance?

Responses to strenuous exercise, as indicated by stress‐related markers such as intestinal integrity markers and myokines, showed high test–retest variation. Even in well‐trained young men an adapted response is seen after a single repetition after 1 week. This finding has implications for the design of studies aimed at evaluating physiological responses to exercise.

Strenuous exercise induces different stress‐related physiological changes, potentially including changes in intestinal barrier function. In the Protégé Study (ISRCTN14236739; www.isrctn.com), we determined the test–retest repeatability in responses to exercise in well‐trained individuals. Eleven well‐trained men (27 ± 4 years old) completed an exercise protocol that consisted of intensive cycling intervals, followed by an overnight fast and an additional 90 min cycling phase at 50% of maximal workload the next morning. The day before (rest), and immediately after the exercise protocol (exercise) a lactulose and rhamnose solution was ingested. Markers of energy metabolism, lactulose‐to‐rhamnose ratio, several cytokines and potential stress‐related markers were measured at rest and during exercise. In addition, untargeted urine metabolite profiles were obtained. The complete procedure (Test) was repeated 1 week later (Retest) to assess repeatability. Metabolic effect parameters with regard to energy metabolism and urine metabolomics were similar for both the Test and Retest period, underlining comparable exercise load. Following exercise, intestinal permeability (1 h plasma lactulose‐to‐rhamnose ratio) and the serum interleukin‐6, interleukin‐10, fibroblast growth factor‐21 and muscle creatine kinase concentrations were significantly increased compared with rest only during the first test and not when the test was repeated. Responses to strenuous exercise in well‐trained young men, as indicated by intestinal markers and myokines, show adaptation in Test–Retest outcome. This might be attributable to a carry‐over effect of the defense mechanisms triggered during the Test. This finding has implications for the design of studies aimed at evaluating physiological responses to exercise.
Potassium currents in the heart: functional roles in repolarization, arrhythmia and therapeutics
Authors: Chiamvimonvat Nipavan , Chen‐Izu Ye , Clancy Colleen E. , Deschenes Isabelle , Dobrev Dobromir , Heijman Jordi , Izu Leighton , Qu Zhilin , Ripplinger Crystal M. , Vandenberg Jamie I. , Weiss James N. , Koren Gideon , Banyasz Tamas , Grandi Eleonora , Sanguinetti Michael C. , Bers Donald M. , Nerbonne Jeanne M.
Published: November 2016

This is the second of the two White Papers from the fourth UC Davis Cardiovascular Symposium Systems Approach to Understanding Cardiac Excitation–Contraction Coupling and Arrhythmias (3–4 March 2016), a biennial event that brings together leading experts in different fields of cardiovascular research. The theme of the 2016 symposium was ‘K+ channels and regulation’, and the objectives of the conference were severalfold: (1) to identify current knowledge gaps; (2) to understand what may go wrong in the diseased heart and why; (3) to identify possible novel therapeutic targets; and (4) to further the development of systems biology approaches to decipher the molecular mechanisms and treatment of cardiac arrhythmias. The sessions of the Symposium focusing on the functional roles of the cardiac K+ channel in health and disease, as well as K+ channels as therapeutic targets, were contributed by Ye Chen‐Izu, Gideon Koren, James Weiss, David Paterson, David Christini, Dobromir Dobrev, Jordi Heijman, Thomas O'Hara, Crystal Ripplinger, Zhilin Qu, Jamie Vandenberg, Colleen Clancy, Isabelle Deschenes, Leighton Izu, Tamas Banyasz, Andras Varro, Heike Wulff, Eleonora Grandi, Michael Sanguinetti, Donald Bers, Jeanne Nerbonne and Nipavan Chiamvimonvat as speakers and panel discussants. This article summarizes state‐of‐the‐art knowledge and controversies on the functional roles of cardiac K+ channels in normal and diseased heart. We endeavour to integrate current knowledge at multiple scales, from the single cell to the whole organ levels, and from both experimental and computational studies.
Scaling Laws for the Peak Overpressure of a Cannon Blast
Authors: Carson Robert A. , Sahni Onkar
Published: November 2016

For large cannons, blast overpressure can have a detrimental effect on the crew in the near field (i.e., within a distance of 50 tube diameters or calibers from the muzzle center) as well as on the support personnel and equipment in the far field (i.e., at a distance greater than 50 calibers). Therefore, an efficient method to determine the peak overpressure due to a cannon blast is highly desired. In this study, we investigate scaling laws for the peak overpressure, due to the primary blast of a large cannon, with the aim that they can be applied as an efficient method to evaluate the peak overpressure in the far field. We explore two types of scaling laws; each type is based on a power-law model involving a prefactor and an exponent as model parameters. The two types of the power-law models differ in the way they incorporate the polar angle dependence. The first type was proposed by Fansler and Schmidt (1983, “The Prediction of Gun Muzzle Blast Properties Utilizing Scaling,” U.S. Army Ballistic Research Laboratory, Aberdeen Proving Ground, MD, Report No. ARBRL-TR-02504). They developed a muzzle-center based scaling law (MCSL) in which the polar angle dependence was incorporated through a reference length scale to define a nondimensional or scaled radial distance from the muzzle center and the model parameters were independent of the polar angle. They calibrated the parameters by employing least-squares fit to a wide range of experimental data. In this study, we recalibrated or updated the parameters for the current cannon by using the numerical simulation data for the cannon blast in the near field. Additionally, we developed a second type of scaling law in which the radial distance is defined from the blast center (in contrast to the muzzle center) and scaled using the inner tube diameter. In this model, the angular dependence is incorporated directly into the model parameters. For this model too, we calibrated the parameters by using the numerical simulation data. We observe that both the modified version of the muzzle-center based scaling law as well as the blast-center based scaling law (BCSL) show a significantly closer fit to the numerical and experimental data and achieve a similar level of accuracy. This indicates that the current form or structure of the two types of power-law based scaling models is able to fit well with the near-field data; however, the current methodology requires a calibration process for a given cannon of interest. In the future, with far field data, we plan to evaluate predictions in the far field.
Investigation of Hydro-Mechanical Losses in External Gear Machines: Simulation and Experimental Validation
Authors: Thiagarajan Divya , Vacca Andrea
Published: November 2016

This paper presents a comprehensive study to estimate the total torque losses which contribute to the hydro-mechanical efficiency in external gear machines (EGMs). A study of these losses at different operating conditions is an important design factor in prototyping many positive displacement machines to achieve efficient and reliable designs.

Although semi-empirical models for the description of the steady-state behavior of positive displacement machines accounting for both volumetric and torque losses are available in literature, their fidelity is often based on the availability of reliable experimental data. In the case of EGMs, it is difficult to consider intricate operating features such as the micro-motion of the different components in these generic models. A numerical evaluation of these special features in an EGM using dedicated models for EGMs can potentially contribute to an accurate prediction of the hydro-mechanical efficiency of a given design.

In the present work, different sources of the torque losses are methodically determined for a reference EGM unit through various numerical models which were previously developed and validated in the authors’ research team. The cumulative predictions of the torque losses from the different simulation models are then validated against the corresponding measured experimental torque losses at various operating conditions for the reference EGM unit.
Development of the Independent Metering Valve Control System and Analysis of its Performance for an Excavator
Authors: Lee Jong-Chan , Jin Ki-Chang , Kwon Young-Min , Choi Lim-Gook , Choi Jae-Yoon , Lee Byung-Kyu
Published: November 2016

As an effort to develop more efficient system for an excavator, EH (Electro-Hydraulic) system has been widely adopted to take the advantage of the well-commercialized EH valves and its control technologies[1]. Utilizing the EH technology, an innovative IMV (Independent Metering Valve) control system for an excavator mechanism, which consists of high capacity EH valve blocks, an electric-controlled pump, and a main controller unit, has been developed by Hyundai Heavy Industries Co., Ltd. This IMV control system can provide tremendous flexibility to the control of cylinder movements and reduce the energy consumption of an excavator.

In this paper, we introduce the major features of the developed IMV control system and propose the novel control algorithm considering optimal power distribution and energy saving. Furthermore, the effectiveness of the proposed system and control algorithm is verified through various experiments conducted on an excavator equipped with the IMV control system. The results are compared with those of conventional machine. It was shown that IMV system could save the energy consumption more than 10% of an excavator.
Flow Reactions Prediction in Roto-Translating Valve Through CFD Simulations
Authors: Marani Pietro , Ferrari Cristian , Ruggeri Massimiliano
Published: November 2016

In this work a Computational Fluid Dynamic (CFD) analysis was applied to the design and optimization of a novel concept roto-translating (RT) valve.

A Roto-Translating valve is a spool type valve assembled to a moving sleeve. The two parts are controlled by two independent actuators and are placed inside the valve body. The valve features both basic logic functions (AND, OR), and advanced control techniques. From the safety viewpoint it offers a fail-operational characteristic thanks to operational redundancy and functional diversity. Moreover the control flexibility allows to get rid of the need of a specific spool design for each different application. One of the goals of the valve is to enhance the speed and precision achievable by the use of two concurrent actuators; for this reason it is fundamental to study the flow forces effect that could adversely affect both rotating and linear motion.

In the field of hydraulic valves design the Flow Force, generated by the acceleration of fluid flow across the metering edges, is an important phenomenon to be considered for the study of the operation and dynamics of the valve. Differently from common spool valves, in this new kind of valve two types of reaction to fluid flow are present: the Flow Force and the Flow Torque.

The first is the well-known axial Flow Force which is generated from the variation of axial component of momentum of the fluid flow and was studied by several authors. The second type of reaction can be identified as a Flow Torque, a less investigated argument. Basically the Flow Torque, equivalently to Flow Force, is linked to the variation of the component of fluid momentum, but in this case in circumferential direction and effects the mutual rotation of the two metering elements.

A complete map of operative conditions, 5 angular positions and 5 linear displacements have been investigated, simulating all the combinations of 4 different pressure ranges. This approach generates a quite large matrix of 25 results for each of the 4 working pressure conditions. For each run the pressure and velocity gradients have been recorded and the flow and torques forces have been computed. These data allow the validation of the sizing of both electric valve actuators, in order to define the operational limits of the valve in terms of pressure drop and flow rate. This activity could also inspire new solutions for a further geometric optimization of the design.
Modeling and Experimental Validation of a Reed Check Valve for Hydraulic Applications
Authors: Knutson Anthony L. , Van de Ven James D.
Published: November 2016

Reed valves are a type of check valve commonly found in a wide range of applications including air compressors, internal combustion engines, and even the human heart. While reed valves have been studied extensively in these applications, published research on the modeling and application of reed valves in hydraulic systems is severely lacking. Because the spring and mass components of a reed valve are contained in a single element, it is light and compact compared to traditional disc, poppet, or ball style check valves. These advantages make reed valves promising for use in high frequency applications such as piston pumps, switch-mode hydraulics, and digital hydraulics. Furthermore, the small size and fast response of reed valves provide an opportunity to design pumps capable of operating at higher speeds and with lower dead volumes, thus increasing efficiency and power density. In this paper, a modeling technique for reed valves is presented and validated in a hydraulic piston pump test bed. Excellent agreement between modeled and experimentally measured reed valve opening is demonstrated. Across the range of experimental conditions, the model predicts the pump delivery with an error typically less than 1% with a maximum error of 2.2%.
Photosymbiosis and the expansion of shallow-water corals
Authors: Frankowiak Katarzyna , Wang Xingchen T. , Sigman Daniel M. , Gothmann Anne M. , Kitahara Marcelo V. , Mazur Maciej , Meibom Anders , Stolarski Jarosław
Published: November 2016

New isotopic and microstructural data suggest that the Tethyan Triassic corals were predominantly photosymbiotic.
All-printed magnetically self-healing electrochemical devices
Authors: Bandodkar Amay J. , López Cristian S. , Vinu Mohan Allibai Mohanan , Yin Lu , Kumar Rajan , Wang Joseph
Published: November 2016

Researchers develop self-healing inks for realizing printed electronics that can instantly recover millimeter-sized cracks.
Controversial HIV vaccine strategy gets a second chance
Authors: Cohen Jon
Published: November 2016

Modest success in Thailand inspires South Africa trial
Data Check: California rules U.S. corporate research
Authors: Mervis Jeffrey
Published: November 2016

New NSF survey finds that California has widened its lead over the rest of the country in state-by-state analysis of what companies spend on research.
Mouse with a milkshake: Behavioral windows into brain function
Authors: Smith Caitlin
Published: November 2016

Neuroscientists are employing new techniques and technologies to use animal behavior as a window into brain function.For instance, researchers are teaching mice to nose-poke a touchscreen by doling out strawberry milkshakes as part ofcognitive testing. It's a light-hearted reminder of the similarity between mice and humans, perhaps—but hopes are risingthat new therapies developed using mouse models of Alzheimer's disease, for example, can be translated to humans.

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Injury-induced
ctgfa
directs glial bridging and spinal cord regeneration in zebrafish
Authors: Mokalled Mayssa H. , Patra Chinmoy , Dickson Amy L. , Endo Toyokazu , Stainier Didier Y. R. , Poss Kenneth D.
Published: November 2016

Spinal cord regeneration in zebrafish

Unlike humans, zebrafish can regenerate their spinal cord. Mokalled
et al.
identified a growth factor in zebrafish that helps this process (see the Perspective by Williams and He). The protein encoded by
ctgfa
(
connective tissue growth factor a
) is secreted after injury and encourages glial cells to form a bridge across the spinal lesion. Addition of this protein improved spinal cord repair in injured zebrafish.

Science
, this issue p.
630
; see also p.
544
Quantifying the evolution of individual scientific impact
Authors: Sinatra Roberta , Wang Dashun , Deville Pierre , Song Chaoming , Barabási Albert-László
Published: November 2016

Scientific impact—that is the
Q

Are there quantifiable patterns behind a successful scientific career? Sinatra
et al.
analyzed the publications of 2887 physicists, as well as data on scientists publishing in a variety of fields. When productivity (which is usually greatest early in the scientist's professional life) is accounted for, the paper with the greatest impact occurs randomly in a scientist's career. However, the process of generating a high-impact paper is not an entirely random one. The authors developed a quantitative model of impact, based on an element of randomness, productivity, and a factor
Q
that is particular to each scientist and remains constant during the scientist's career.

Science
, this issue p.
596
Buffer-gas cooling of antiprotonic helium to 1.5 to 1.7 K, and antiproton-to–electron mass ratio
Authors: Hori Masaki , Aghai-Khozani Hossein , Sótér Anna , Barna Daniel , Dax Andreas , Hayano Ryugo , Kobayashi Takumi , Murakami Yohei , Todoroki Koichi , Yamada Hiroyuki , Horváth Dezső , Venturelli Luca
Published: November 2016

Exotic molecule tests fundamental symmetry

Spectroscopy of exotic molecules can offer insight into fundamental physics. Hori
et al.
studied the transition frequencies of an unusual helium atom in which one of the two electrons was substituted by an antiproton, the negatively charged antiparticle partner of the proton (see the Perspective by Ubachs). The antiprotonic helium was cooled down to low temperatures to allow the frequencies to be measured with high precision. The extracted mass of the antiproton (relative to the electron mass) was in good agreement with previous measurements of the proton mass. This finding is in keeping with the implications of the combined charge, parity, and time-reversal symmetry of physical laws.

Science
, this issue p.
610
; see also p.
546
Pain regulation by non-neuronal cells and inflammation
Authors: Ji Ru-Rong , Chamessian Alexander , Zhang Yu-Qiu
Published: November 2016

Acute pain is protective and a cardinal feature of inflammation. Chronic pain after arthritis, nerve injury, cancer, and chemotherapy is associated with chronic neuroinflammation, a local inflammation in the peripheral or central nervous system. Accumulating evidence suggests that non-neuronal cells such as immune cells, glial cells, keratinocytes, cancer cells, and stem cells play active roles in the pathogenesis and resolution of pain. We review how non-neuronal cells interact with nociceptive neurons by secreting neuroactive signaling molecules that modulate pain. Recent studies also suggest that bacterial infections regulate pain through direct actions on sensory neurons, and specific receptors are present in nociceptors to detect danger signals from infections. We also discuss new therapeutic strategies to control neuroinflammation for the prevention and treatment of chronic pain.
Neural circuits for pain: Recent advances and current views
Authors: Peirs Cedric , Seal Rebecca P.
Published: November 2016

The mammalian nervous system encodes many different forms of pain, from those
that arise as a result of short-term low-grade interactions with noxious
thermal, chemical, or mechanical sources to more serious forms of pain induced
by trauma and disease. In this Review, we highlight recent advances in our
understanding of the neural circuits that encode these types of pain. Promising
therapeutic strategies based on recent advances are also highlighted.
Deconstructing the sensation of pain: The influence of cognitive processes on pain perception
Authors: Wiech Katja
Published: November 2016

Phenomena such as placebo analgesia or pain relief through distraction highlight the powerful influence cognitive processes and learning mechanisms have on the way we perceive pain. Although contemporary models of pain acknowledge that pain is not a direct readout of nociceptive input, the neuronal processes underlying cognitive modulation are not yet fully understood. Modern concepts of perception—which include computational modeling to quantify the influence of cognitive processes—suggest that perception is critically determined by expectations and their modification through learning. Research on pain has just begun to embrace this view. Insights into these processes promise to open up new avenues to pain prevention and treatment by harnessing the power of the mind.
Mutational signatures associated with tobacco smoking in human cancer
Authors: Alexandrov Ludmil B. , Ju Young Seok , Haase Kerstin , Van Loo Peter , Martincorena Iñigo , Nik-Zainal Serena , Totoki Yasushi , Fujimoto Akihiro , Nakagawa Hidewaki , Shibata Tatsuhiro , Campbell Peter J. , Vineis Paolo , Phillips David H. , Stratton Michael R.
Published: November 2016

Assessing smoke damage in cancer genomes

We have known for over 60 years that smoking tobacco is one of the most avoidable risk factors for cancer. Yet the detailed mechanisms by which tobacco smoke damages the genome and creates the mutations that ultimately cause cancer are still not fully understood. Alexandrovet al.examined mutational signatures and DNA methylation changes in over 5000 genome sequences from 17 different cancer types linked to smoking (see the Perspective by Pfeifer). They found a complex pattern of mutational signatures. Only cancers originating in tissues directly exposed to smoke showed a signature characteristic of the known tobacco carcinogen benzo[a]pyrene. One mysterious signature was shared by all smoking-associated cancers but is of unknown origin. Smoking had only a modest effect on DNA methylation.

Science, this issue p.618; see also p.549
Against all odds
A Most Improbable Journey A Big History of Our Planet and Ourselves
Walter Alvarez
Norton, 2016. 256 pp.
Authors: Schneiderman Jill S.
Published: November 2016

A geologist revels in the unlikely reality of life on Earth
A testing time for antimatter
Authors: Ubachs Wim
Published: November 2016

Precision measurement of antiprotonic helium provides a test of physical laws
Migratory birds under threat
Authors: Bairlein Franz
Published: November 2016

Habitat degradation and loss, illegal killings, and climate change threaten European migratory bird populations
One brain, many genomes
Authors: Evrony Gilad D.
Published: November 2016

Single-cell genomic techniques shed light on somatic mutations in brain development and neurologic disorders
Forecasting the opioid epidemic
Authors: Burke Donald S.
Published: November 2016

Since 2000, almost half a million Americans have died from drug overdoses. This modern plague—largely driven by opioid addiction—degrades health, saps productivity, spawns crime, and devastates families, all at enormous societal cost. How did we get here, and what do we do now?
Superior Protection from Live-Attenuated Vaccines Directed against Johne's Disease
Authors: Shippy Daniel C. , Lemke Justin J. , Berry Aubrey , Nelson Kathryn , Hines Murray E. , Talaat Adel M.
Published: November 2016

Mycobacterium aviumsubsp.paratuberculosis(M. paratuberculosis) is the etiological agent of Johne's disease in ruminants. Johne's disease is an important enteric infection causing large economic losses associated with infected herds. In an attempt to fight this infection, we created two novel live-attenuated vaccine candidates with mutations insigHandlipN(pgsH and pgsN, respectively). Earlier reports in mice suggested these vaccines are promising candidates to fight Johne's disease in ruminants. In this study, we tested the performances of the two constructs as vaccine candidates using the goat model of Johne's disease. Both vaccines appeared to provide significant immunity to goats against challenge from wild-typeM. paratuberculosis. The pgsH and pgsN constructs showed a significant reduction in histopathological lesions and tissue colonization compared to nonvaccinated goats and those vaccinated with an inactivated vaccine. Unlike the inactivated vaccine, the pgsN construct was able to eliminate fecal shedding from challenged animals, a feature that is highly desirable to control Johne's disease in infected herds. Furthermore, strong initial cell-mediated immune responses were elicited in goats vaccinated with pgsN that were not demonstrated in other vaccine groups. Overall, the results indicate the potential use of live-attenuated vaccines to control intracellular pathogens, includingM. paratuberculosis, and warrant further testing in cattle, the main target for Johne's disease control programs.
Double negative and positive control of tsx expression in Escherichia coli
Authors: Bremer E , Gerlach P , Middendorf A
Published: November 2016

The Escherichia coli tsx gene encodes an outer membrane protein that is involved in nucleoside uptake and serves as the receptor protein for colicin K and several bacteriophages. Regulation of its expression was studied by using tsx-lacZ protein and operon fusion strains carrying mutations in deoR, cytR, and crp. The cytR-encoded repressor had a stronger influence on tsx transcription than the DeoR repressor did, and the level of tsx expression in a deoR cytR double mutant was approximately the sum of those found in the single deoR and cytR strains. This double negative control of Tsx synthesis was superceded by a positive control mechanism mediated by the cyclic AMP-catabolite activator protein (cAMP-CAP) complex. Our results suggest that tsx expression is controlled at two separate and differently regulated promoters: the weaker promoter (P1) is repressible by DeoR, while the stronger promoter (P2) is subject to negative and positive control by the CytR repressor and the cAMP-CAP complex, respectively. A mutant was isolated that showed unaltered tsx regulation by DeoR and the cAMP-CAP complex but strongly reduced repression by CytR. This tsx operator mutant was used to obtain a suppressor mutation located on a plasmid carrying the cloned cytR gene that restored CytR control of tsx expression. The direction of tsx transcription was determined and found to be counterclockwise on the E. coli chromosome.
Requirement of heat-labile cytoplasmic protein factors for posttranslational translocation of OmpA protein precursors into Escherichia coli membrane vesicles
Authors: Weng Q P , Chen L L , Tai P C
Published: November 2016

The involvement of possible cytoplasmic factors in ATP-dependent postttranslational translocation of proteins into Escherichia coli membrane vesicles was examined. The precursor of OmpA protein was partially purified by DEAE-cellulose chromatography, and its translocation was found to require material from the soluble cytoplasmic fraction. The fractionated active cytoplasmic translocation factor (CTF) was protease sensitive, micrococcal nuclease insensitive, N-ethylmaleimide resistant, and heat labile. The heat sensitivity of the CTF allowed its specific and preferential inactivation in the crude-precursor synthesis mixture, which provided a simple and rapid assay procedure for the factor during purification. Two active fractions were detected upon further fractionation: the major one was about 8S in sucrose gradient centrifugation and 120 kilodaltons by Sephadex filtration, whereas the other was about 4S and 60 kilodaltons in sucrose gradient centrifugation and by Sephadex filtration, respectively. The active fractions could also be fractionated by DEAE-Sepharose chromatography. These CTFs are apparently different from the previously reported 12S export factor (M. Muller and G. Blobel, Proc. Natl. Acad. Sci. USA 81:7737-7741, 1984).
Changes in the hydrophobic-hydrophilic cell surface character of Halomonas elongata in response to NaCl
Authors: Hart D J , Vreeland R H
Published: November 2016

Phase-partitioning studies of the euryhaline bacterium Halomonas elongata demonstrated that the hydrophobic-hydrophilic nature of the cell surface changed as the bacterium grew in different NaCl concentrations. Mid-log-phase cells grown in a high (3.4 M) NaCl concentration were more hydrophilic than were cells grown in a low (0.05 M) NaCl concentration. Mid-log-phase cells from defined medium containing 3.4 M NaCl normally produced a hydrophobicity reading of only 14 (hexadecane hydrophobicity = 100), while corresponding cells from defined medium containing 0.05M NaCl gave a hydrophobicity reading of 90. Compared with cells grown in low salt concentrations, cells grown in high salt concentrations were more hydrophilic at all stages of growth. Rapid suspension of log-phase cells grown in 1.37 M NaCl into a 0.05 or 3.4 M NaCl solution produced no detectable rapid changes in surface hydrophobicity. These data suggest that as H. elongata adapts to different NaCl concentrations, it alters the affinity of its outermost cell surface to water.
Sequence and transcriptional start site of the Pseudomonas aeruginosa outer membrane porin protein F gene
Authors: Duchêne M , Schweizer A , Lottspeich F , Krauss G , Marget M , Vogel K , von Specht B U , Domdey H
Published: November 2016

Porin F is one of the major proteins of the outer membrane of Pseudomonas aeruginosa. It forms water-filled pores of variable size. Porin F is a candidate for a vaccine against P. aeruginosa because it antigenically cross-reacts in all serotype strains of the International Antigenic Typing Scheme. We have isolated the gene for porin F from a lambda EMBL3 bacteriophage library by using oligodeoxynucleotide hybridization probes and have determined its nucleotide sequence. Different peptide sequences obtained from isolated porin F confirmed the deduced protein sequence. The mature protein consists of 326 amino acid residues and has a molecular weight of 35,250. The precursor contains an N-terminal signal peptide of 24 amino acid residues. S1 protection and primer extension experiments, together with Northern (RNA) blots, indicate that the mRNA coding for porin F is monocistronic with short untranslated regions of about 58 bases at the 5' end and about 47 bases at the 3' end. The sequences in the -10 and -35 regions upstream of the transcriptional start site are closely related to the Escherichia coli promoter consensus sequences, which explains why the porin F gene is expressed in E. coli under the control of its own promoter. The amino acid sequence of porin F is not homologous to the different E. coli porins OmpF, OmpC, LamB, and PhoE. On the other hand, a highly homologous region of 30 amino acids between the OmpA proteins of different enteric bacteria and porin F of P. aeruginosa was detected. The core region of the homology to E. coli OmpA had 11 of 12 amino acid residues in common.
An iron-antagonized fungistatic agent that is not required for iron assimilation from a fluorescent rhizosphere pseudomonad
Authors: Gill P R , Warren G J
Published: November 2016

Fluorescent rhizosphere Pseudomonas sp. strain NZ130 promotes plant growth, and may do so in part because of its production of a growth inhibitory factor that is active against phytopathogenic fungi. Analysis of the inhibitory factor that is active against the phytopathogen Pythium ultimum showed that its activity is antagonized at iron concentrations above 10 microM. The iron-antagonized inhibitor was separated from the fluorescent siderophore of this pseudomonad by gel filtration. Mutants that lacked either the iron-antagonized inhibitor or the fluorescent siderophore were isolated. Results of complementation analysis of these mutants by use of a cosmid library indicated that distinct DNA sequences are required for the production of each factor. Analysis of isogenic mutant strains showed that the genetic requirements for the production of the iron-antagonized inhibitor and the fluorescent siderophore are different, and that only the fluorescent siderophore is required for iron assimilation. Fusions of these same sequences to a beta-galactosidase gene were used to show that the regions required for the production of both the fluorescent siderophore and the iron-antagonized inhibitor were iron-regulated.
Nucleotide sequence of the Salmonella typhimurium mutS gene required for mismatch repair: homology of MutS and HexA of Streptococcus pneumoniae
Authors: Haber L T , Pang P P , Sobell D I , Mankovich J A , Walker G C
Published: November 2016

The mutS gene product of Escherichia coli and Salmonella typhimurium is one of at least four proteins required for methyl-directed mismatch repair in these organisms. A functionally similar repair system in Streptococcus pneumoniae requires the hex genes. We have sequenced the S. typhimurium mutS gene, showing that it encodes a 96-kilodalton protein. Amino-terminal amino acid sequencing of purified S. typhimurium MutS protein confirmed the initial portion of the deduced amino acid sequence. The S. typhimurium MutS protein is homologous to the S. pneumoniae HexA protein, suggesting that they arose from a common ancestor before the gram-negative and gram-positive bacteria diverged. Overall, approximately 36% of the amino acids of the two proteins are identical when the sequences are optimally aligned, including regions of stronger homology which are of particular interest. One such region is close to the amino terminus. Another, located closer to the carboxy terminus, includes homology to a consensus sequence thought to be diagnostic of nucleotide-binding sites. A third one, adjacent to the second, is homologous to the consensus sequence for the helix-turn-helix motif found in many DNA-binding proteins. We found that the S. typhimurium MutS protein can substitute for the E. coli MutS protein in vitro as it can in vivo, but we have not yet been able to demonstrate a similar in vitro complementation by the S. pneumoniae HexA protein.