bluuebunny/crossref_metadata_2025 huggingface dataset:
Structures of MoxW(3−x)O6 (x=–3) anion and neutral clusters determined by anion photoelectron spectroscopy and density functional theory calculations
Authors: Rothgeb David W. , Hossain Ekram , Kuo Angela T. , Troyer Jennifer L. , Jarrold Caroline Chick
Published: July 2009

The structures of Mo3O6, Mo2WO6, MoW2O6, and W3O6 and their associated anions were studied using a combination of anion photoelectron (PE) spectroscopy and density functional theory calculations. The 3.49 eV photon energy anion PE spectra of all four species showed broad electronic bands with origins near 2.8 eV. Calculations predict that low-spin, cyclic structures are the lowest energy isomers for both the anion and neutral species. The lowest energy neutral structures for all four species are analogous, C3v (Mo3O6 and W3O6) or Cs (mixed clusters) symmetry structures in which all three metal atoms are in formally equivalent oxidation states, with singlet ground electronic states. The lowest energy isomers predicted for Mo3O6− and W3O6− are the same with doublet electronic states. The lowest energy structures calculated for the mixed anions are lower symmetry, with the tungsten centers in higher oxidation states than the molybdenum centers. However, Cs symmetry structures are competitive, and appear to be the primary contributors to the observed spectra. Spectral simulations based on calculated spectroscopic parameters validate the assignments. This series of clusters is strikingly different from the Mo2O4/MoWO4/W2O4 anion and neutral series described recently [Mayhall et al., J. Chem. Phys. 130, 124313 (2009)]. While the average oxidation state is the same for both series, the structures determined for the Mo2O4/MoWO4/W2O4 anions and neutrals were dissimilar and lower symmetry, and high spin states were energetically favored. This difference is attributed to the large stabilizing effect of electronic delocalization in the more symmetric trimetallic cyclic structures that is not available in the bimetallic species.
Anomalous diffusion in supercooled liquids: A long-range localization in particle trajectories
Authors: Oppelstrup T. , Dzugutov M.
Published: July 2009

A statistical analysis of the geometries of particle trajectories in the supercooled liquid state is reported. The analysis we present here is based on the statistics of the first-passage trajectory length. We examine two structurally different fragile glass-forming liquids simulated by molecular dynamics. In both liquids, the trajectories are found to reveal three distinct diffusion regimes. A short-range confinement to the cage of nearest neighbors is followed by a persistent diffusion regime. At a still larger spatial scale, the particle trajectories demonstrate a novel diffusion anomaly: a long-range localization distinct from the short-range localization. This phenomenon can be interpreted in terms of the potential-energy landscape topography with the local energy minima coalescing into metabasins—compact domains with low escape probability. We also demonstrate that the persistent diffusion regime can be linked to the exponential decay of the self-part of the van Hove correlation function.
Ultrasensitive dual phosphorylation dephosphorylation cycle kinetics exhibits canonical competition behavior
Authors: Huang Qingdao , Qian Hong
Published: July 2009

We establish a mathematical model for a cellular biochemical signaling module in terms of a planar differential equation system. The signaling process is carried out by two phosphorylation-dephosphorylation reaction steps that share common kinase and phosphatase with saturated enzyme kinetics. The pair of equations is particularly simple in the present mathematical formulation, but they are singular. A complete mathematical analysis is developed based on an elementary perturbation theory. The dynamics exhibits the canonical competition behavior in addition to bistability. Although widely understood in ecological context, we are not aware of a full range of biochemical competition in a simple signaling network. The competition dynamics has broad implications to cellular processes such as cell differentiation and cancer immunoediting. The concepts of homogeneous and heterogeneous multisite phosphorylation are introduced and their corresponding dynamics are compared: there is no bistability in a heterogeneous dual phosphorylation system. A stochastic interpretation is also provided that further gives intuitive understanding of the bistable behavior inside the cells.
Targeting neural precursors in the adult brain rescues injured dopamine neurons
Authors: Androutsellis-Theotokis Andreas , Rueger Maria A. , Park Deric M. , Mkhikian Haik , Korb Erica , Poser Steve W. , Walbridge Stuart , Munasinghe Jeeva , Koretsky Alan P. , Lonser Russel R. , McKay Ronald D.
Published: July 2009

In Parkinson's disease, multiple cell types in many brain regions are afflicted. As a consequence, a therapeutic strategy that activates a general neuroprotective response may be valuable. We have previously shown that Notch ligands support neural precursor cells in vitro and in vivo. Here we show that neural precursors express the angiopoietin receptor Tie2 and that injections of angiopoietin2 activate precursors in the adult brain. Signaling downstream of Tie2 and the Notch receptor regulate blood vessel formation. In the adult brain, angiopoietin2 and the Notch ligand Dll4 activate neural precursors with opposing effects on the density of blood vessels. A model of Parkinson's disease was used to show that angiopoietin2 and Dll4 rescue injured dopamine neurons with motor behavioral improvement. A combination of growth factors with little impact on the vasculature retains the ability to stimulate neural precursors and protect dopamine neurons. The cellular and pharmacological basis of the neuroprotective effects achieved by these single treatments merits further analysis.
Post-Traumatic Stress Impacts on Quality of Life in Children After Road Traffic Accidents: Prospective Study
Authors: Landolt Markus A. , Vollrath Margarete E. , Gnehm Hanspeter E. , Sennhauser Felix H.
Published: July 2009

Objective: There is little knowledge on health-related quality of life (HRQOL) of injured children and adolescents after road traffic accidents (RTA). Although findings in injured adults suggest that post-traumatic stress symptoms (PTSS) may be important predictors of HRQOL, this issue has never been prospectively examined in children. The aim of the present study was therefore to prospectively assess HRQOL in children after RTA and specifically examine the impact of PTSS on HRQOL.

Method: Sixty-eight children (aged 6.5–14.5 years) were interviewed 1 month and 1 year after an RTA using the Child PTSD Reaction Index and the Toegepast Natuurwetenschappelijk Onderzoek-Academisch Ziekenhuis Leiden (TNO-AZL) Questionnaire for Children's Health-Related Quality of Life. Parents and physicians were assessed with questionnaires.

Results: Eleven children (16.2%) showed moderate to severe post-traumatic stress reactions at 1 month, and 12 children (17.6%) at 1 year. At 1 month, patients reported reduced motor functioning and autonomy and impairments in some parts of emotional functioning compared to a community sample. At 1 year all dimensions of HRQOL were within or above normal ranges. Multivariate analysis indicated that PTSS at 1 month significantly predicted HRQOL at 1 year.

Conclusions: This prospective study provides evidence for a long-term negative influence of early PTSS on HRQOL in injured children. The return of injured children to pre-injury HRQOL may therefore not only depend on optimal medical care but also on awareness and timely interventions regarding PTSS.
Design and Control of a Lower Limb Exoskeleton for Robot‐Assisted Gait Training
Authors: Beyl Pieter , Van Damme Michaël , Van Ham Ronald , Vanderborght Bram , Lefeber Dirk
Published: July 2009

Robot‐assisted rehabilitation of gait still faces many challenges, one of which is improving physical human‐robot interaction. The use of pleated pneumatic artificial muscles to power a step rehabilitation robot has the potential to meet this challenge. This paper reports on the development of a gait rehabilitation exoskeleton with a knee joint powered by pleated pneumatic artificial muscles. It is intended as a platform for the evaluation of design and control concepts in view of improved physical human‐robot interaction. The design was focused on the optimal dimensioning of the actuator configuration. Safety being the most important prerequisite, a proxy‐based sliding mode controller (PSMC) was implemented as it combines accurate tracking during normal operation with a smooth, slow and safe recovery from large position errors. Treadmill walking experiments of a healthy subject wearing the powered exoskeleton show the potential of PSMC as a safe robot‐in‐charge control strategy for robot‐assisted gait training.
Bio‐Inspired Control of an Arm Exoskeleton Joint with Active‐Compliant Actuation System
Authors: Folgheraiter Michele , de Gea Jose , Bongardt Bertold , Albiez Jan , Kirchner Frank
Published: July 2009

This paper presents the methodology followed on the design of a multi‐contact point haptic interface that uses a bio‐inspired control approach and a novel actuation system. The combination of these components aims at creating a system that increases the operability of the target, and, at the same time, enables an intuitive and safe tele‐operation of any complex robotic system of any given morphology. The novelty lies on the combination of a thoughtful kinematic structure driven by an active‐compliant actuation system and a bio‐inspired paradigm for its regulation. Due to the proposed actuation approach, the final system will achieve the condition of wearable system. On that final solution, each joint will be able to change its stiffness depending on the task to be executed, and on the anatomical features of each individual. Moreover, the system provides a variety of safety mechanisms at different levels to prevent causing any harm to the operator. In future, the system should allow the complete virtual immersion of the user within the working scenario.
Design of a 2‐Finger Hand Exoskeleton for Finger Stiffness Measurements
Authors: Fiorilla Angelo Emanuele , Tsagarakis Nikos G. , Nori Francesco , Sandini Giulio
Published: July 2009

Recent studies of human arm movements have suggested that the control of stiffness may be important both for maintaining stability and for achieving differences in movement accuracy. Several studies in the robotic field demonstrated that grasp stiffness is useful for modelling and controlling manipulators but, even though it is accredited that having models of the human finger impedance would be very desirable for the control of anthropomorphous robot′s hands, relatively few studies have focused on finger and hand stiffness. To allow the measurement of such entities at the finger level, an appropriate device capable of applying fast force transients while at the same time be able to monitor the finger movements is required. The work presented in this paper is a very detailed report about the design of a new hand exoskeleton system that will be used in our future works to investigate the finger stiffness range in different grasping postures and conditions.
Can Infants Use a Nonhuman Agent's Gaze Direction to Establish Word–Object Relations?
Authors: O'Connell Laura , Poulin‐Dubois Diane , Demke Tamara , Guay Amanda
Published: July 2009

Adopting a procedure developed with human speakers, we examined infants' ability to follow a nonhuman agent's gaze direction and subsequently to use its gaze to learn new words. When a programmable robot acted as the speaker (Experiment 1), infants followed its gaze toward the word referent whether or not it coincided with their own focus of attention, but failed to learn a new word. When the speaker was human, infants correctly mapped the words (Experiment 2). Furthermore, when the robot interacted contingently, this did not facilitate infants' word mapping (Experiment 3). These findings suggest that gaze following upon hearing a novel word is not sufficient to learn the referent of the word when the speaker is nonhuman.
Infants' Processing of Featural and Configural Information in the Upper and Lower Halves of the Face
Authors: Quinn Paul C. , Tanaka James W.
Published: July 2009

Three‐ to 4‐month‐old and 6‐ to 7‐month‐old infants were administered an infant version of the Face Dimensions Test that has been used with adults (e.g., Bukach, Le Grand, Kaiser, Bub, & Tanaka, 2008). Infants were familiarized with a photograph of a woman's face and then tested with the familiar face paired with a face differing in the (a) distance separating the eyes (a configural/eyes change), (b) distance between the nose and mouth (configural/mouth change), (c) size of the eyes (featural/eyes change), and (d) size of the mouth (featural/mouth change). Infants were shown to be more sensitive to (a) configural than featural change, and (b) change around the eyes versus the mouth. Implications for the development of face processing are discussed.
Moderated effect size and P-value combinations for microarray meta-analyses
Authors: Marot Guillemette , Foulley Jean-Louis , Mayer Claus-Dieter , Jaffrézic Florence
Published: July 2009

Motivation: With the proliferation of microarray experiments and their availability in the public domain, the use of meta-analysis methods to combine results from different studies increases. In microarray experiments, where the sample size is often limited, meta-analysis offers the possibility to considerably increase the statistical power and give more accurate results.

Results: A moderated effect size combination method was proposed and compared with other meta-analysis approaches. All methods were applied to real publicly available datasets on prostate cancer, and were compared in an extensive simulation study for various amounts of inter-study variability. Although the proposed moderated effect size combination improved already existing effect size approaches, the P-value combination was found to provide a better sensitivity and a better gene ranking than the other meta-analysis methods, while effect size methods were more conservative.

Availability: An R package metaMA is available on the CRAN.

Contact:  guillemette.marot@jouy.inra.fr
iBioSim: a tool for the analysis and design of genetic circuits
Authors: Myers Chris J. , Barker Nathan , Jones Kevin , Kuwahara Hiroyuki , Madsen Curtis , Nguyen Nam-Phuong D.
Published: July 2009

Summary:  iBioSim is a tool that supports learning of genetic circuit models, efficient abstraction-based analysis of these models and the design of synthetic genetic circuits. iBioSim includes project management features and a graphical user interface that facilitate the development and maintenance of genetic circuit models as well as both experimental and simulation data records.

Availability:  iBioSim is available for download for Windows, Linux, and MacOS at http://www.async.ece.utah.edu/iBioSim/

Contact:  myers@ece.utah.edu
Does History Matter in Business?
Authors: Tiffany Paul
Published: July 2009

In 2008 Professor Eric Godelier published a provocative essay in which he concluded that a positive dialogue between business historians and both management scientists and business management practitioners was possible. While the divide between these camps was not trivial, he nevertheless wrote that current events and scholarship was bringing them together, at least as he could observe these trends in the context of emerging French scholarship. In this current review, my own conclusion is the opposite. Management scholarship, in fact, continues to move away from the “soft” approach of the historian and more towards the “rigorous” and quantitatively biased methodology of the management sciences. My essay reviews the background of this development in terms of American business practice and scholarship, as it seeks to demonstrate how the evolution of management training in the United States brought us to the current state of affairs where “hard” drives out soft in almost every encounter. However, while I conclude that this is indeed the current reality, I do not imply any endorsement of this outcome. Rather, I end with a hope that some forms of rapprochement might be possible-yet with an acknowledgement that we will have no definitive answers to this question anytime soon.
Cellular basis of uraemic cardiomyopathy: a role for erythropoietin?
Authors: Smith Katie , Semple David , Bhandari Sunil , Seymour Anne‐Marie L.
Published: July 2009

The use of erythropoietin (EPO) has revolutionized the treatment of anaemia associated with many conditions including chronic kidney disease (CKD). However, little is known of the cellular impact of EPO on the uraemic heart. The discovery that the EPO receptor (EPOR) is also expressed on non‐haematopoietic cells including cardiomyocytes highlights a role of EPO beyond haematopoiesis. Animal models of heart failure have shown EPO can potentially reverse cardiac remodelling and improve myocardial function. Damage to the kidney, during uraemia, results in a decreased EPO production, which may render the uraemic heart more susceptible to damage and heart failure. Here we review current data on the cellular actions of EPO in models of left ventricular hypertrophy and heart failure and highlight parallels with the uraemic heart.
Clinical trials update from the European Society of Cardiology heart failure meeting 2009: CHANCE, B‐Convinced, CHAT, CIBIS‐ELD, and Signal‐HF
Authors: Cleland John G.F. , Coletta Alison P. , Torabi Azam , Clark Andrew L.
Published: July 2009

This paper provides information and a commentary on trials relevant to the pathophysiology, prevention, and treatment of heart failure presented at the annual meeting of the Heart Failure Association of the European Society of Cardiology held in Nice. The CHANCE study showed a substantial reduction in morbidity and mortality in a randomized controlled trial (RCT) of a multidisciplinary management programme for patients with chronic heart failure in Russia. Data from the B‐Convinced study, also an RCT, suggest that continuation of beta‐blocker (BB) therapy in patients hospitalized with worsening heart failure may be associated with improved outcomes when compared with treatment discontinuation. The CHAT study suggests that telephone support can improve prognosis in heart failure patients living in remote rural locations. CIBIS‐ELD showed that titration of BBs to target doses in older patients with heart failure is more difficult; but tolerance levels were similar for bisoprolol and carvedilol. Signal‐HF randomized elderly heart failure patients to treatment guided by NT‐proBNP levels or usual care, and showed no effect of NT‐proBNP‐guided treatment on outcomes.
Innovation, endogenous overinvestment, and incentive pay
Authors: Inderst Roman , Klein Manuel
Published: July 2009

We analyze how two key managerial tasks interact: that of growing the business through creating new investment opportunities and that of providing accurate information about these opportunities in the corporate budgeting process. We show how this interaction endogenously biases managers toward overinvesting in their own projects. This bias is exacerbated if managers compete for limited resources in an internal capital market, which provides us with a novel theory of the boundaries of the firm. Finally, managers of more risky and less profitable divisions should obtain steeper incentives to facilitate efficient investment decisions.
Nuclear abnormalities of marine fish erythrocytes
Authors: Strunjak‐Perovic I. , Topic Popovic N. , Coz‐Rakovac R. , Jadan M.
Published: July 2009

The aim of this study was to monitor erythrocyte nuclear abnormalities (NA) including micronuclei (MN) in cultured and wild sea bass Dicentrarchus labrax and wild mullet Mugil spp. Seasonal sampling was performed at seven locations along the eastern coast of the Adriatic Sea. The frequency of NA and MN was positively correlated to temperature (NA: P < 0·05, r = 0·11; MN P < 0·05, r = 0·10), and there was also a positive correlation between NA and MN frequency (P < 0·001, r = 0·43). The lowest NA and MN values for both fish species were recorded in spring, while the highest were recorded in autumn. Significantly higher frequency of NA was seen in D. labrax compared to Mugil spp., while MN frequency was low in both species and not significantly different. There was no significant difference in NA and MN frequency between cultured and wild D. labrax sampled in the same month, and there was no difference between wild Mugil spp. sampled near or far from fish farms. In view of sampling sites, the highest values were detected in fishes from the Limski Channel, the lowest from the Janjina location.
Interspawning interval of wild female three‐spined sticklebackGasterosteus aculeatusin Alaska
Authors: Brown‐Peterson N. J. , Heins D. C.
Published: July 2009

The interspawning interval, or spawning frequency, of wild three‐spined stickleback,Gasterosteus aculeatus, was estimated using histological examination of postovulatory follicles (POF). Females in Alaskan lakes appeared to have as much as a 48 h delay between ovulation and ovoposition, yet the POF method could still be used to estimate the interspawning interval. In two Alaskan lakes the interspawning interval was estimated to range from 2·2 to 7·8 days among individual femaleG. aculeatus. These estimates were consistent with the range (2·5 to 5 days) of previous estimates among individual females from laboratory observations of spawningG. aculeatus, as well as anecdotal accounts of spawning intervals reported from wild populations in Canada (5–10 days). The interspawning interval of females increased during the course of the spawning season in Alaska, showing that the majority of female spawning activity occurred during the earliest portion of the approximate 6‐week reproductive season. The increased interspawning interval appears to be related to a previously reported decrease in body condition in reproductive females during the breeding season. Thus, femaleG. aculeatusmay be unable to sustain the initial rate of reproduction as energy stores that support the rapid growth of vitellogenic oocytes are depleted.
Prevalence of pituitary adenomas: a community‐based, cross‐sectional study in Banbury (Oxfordshire, UK)
Authors: Fernandez Alberto , Karavitaki Niki , Wass John A. H.
Published: July 2009

Background  Pituitary adenomas (PAs) are associated with increased morbidity and mortality. The optimal delivery of services and the provision of care for patients with PAs require distribution of the resources proportionate to the impact of these conditions on the community. Currently, the resource allocation for PAs in the health care system is lacking a reliable and an up‐to‐date epidemiological background that would reflect the recent advances in the diagnostic technologies, leading to the earlier recognition of these tumours.

Objectives  To determine the prevalence, the diagnostic delay and the characteristics of patients with PA in a well‐defined geographical area of the UK (Banbury, Oxfordshire).

Patients and methods  Sixteen general practitioner (GP) surgeries covering the area of Banbury and a total population of 89 334 inhabitants were asked to participate in the study (data confirmed on 31 July 2006). Fourteen surgeries with a total of 81,449 inhabitants (91% of the study population) agreed to take part. All cases of PAs were found following an exhaustive computer database search of agreed terms by the staff of each Practice and data on age, gender, presenting manifestations and their duration, imaging features at diagnosis, history of multiple endocrine neoplasia type 1 and family history of PA were collected.

Results  A total of 63 patients with PA were identified amongst the study population of 81,149, with a prevalence of 77·6 PA cases/100,000 inhabitants (prolactinomas; PRLoma: 44·4, nonfunctioning PAs: 22·2, acromegaly; ACRO: 8·6, corticotroph adenoma: 1·2 and unknown functional status; UFS: 1·2/100,000 inhabitants). The distribution of each PA subtype was for PRLoma 57%, nonfunctioning PAs 28%, ACRO 11%, corticotroph adenoma 2% and UFS 2%. The median age at diagnosis and the duration of symptoms until diagnosis (in years) were for PRLoma 32·0 and 1·5, nonfunctioning PAs 51·5 and 0·8, ACRO 47 and 4·5 and corticotroph adenoma 57 and 7, respectively. PRLoma was the most frequent PA diagnosed up to the age of 60 years (0–20 years: 75% and 20–60 years: 61% of PAs) and nonfunctioning PA after the age of 60 years (60% of PAs). Nonfunctioning PAs dominated in men (57% of all men with PA) and PRLoma in women (76% of all women with PA). Five patients (7·9%) presented with classical pituitary apoplexy, with a prevalence of 6·2 cases/100,000 inhabitants.

Conclusions  Based on a well‐defined population in Banbury (Oxfordshire, UK), we have shown that PAs have a fourfold increased prevalence than previously thought; our data confirm that PAs have a higher burden on the Health Care System and optimal resource distribution for both clinical care and research activities aiming to improve the outcome of these patients are needed.
Should women receive androgen replacement therapy, and if so, how?
Authors: Davis Susan R.
Published: July 2009

The available clinical evidence supports efficacy of testosterone therapy for the treatment of postmenopausal women with hypoactive sexual desire disorder (HSDD) who have undergone a comprehensive clinical evaluation. Although few preparations designed to deliver an appropriate dose of testosterone for women are available, use of testosterone by women for the management of HSDD is widespread. Issues that continue to simulate debate in this therapeutic area include whether HSDD is a condition that merits pharmacotherapy, how effective is such treatment and whether testosterone therapy is safe. Hence the question, should women receive androgen replacement therapy, and if so, how?
Silent corticotroph adenomas have unique recurrence characteristics compared with other nonfunctioning pituitary adenomas
Authors: Cho Hwa Young , Cho Sun Wook , Kim Sang Wan , Shin Chan Soo , Park Kyong Soo , Kim Seong Yeon
Published: July 2009

Objective  The prevalence of silent corticotroph adenomas (SCAs) is not rare among nonfunctioning pituitary adenomas (NFPAs); however, it is unknown whether the clinical significance of SCAs differs from that of NFPAs without ACTH immunoreactivity (non‐SCAs). Our goal was to compare the clinical characteristics and natural history between patients with SCAs and non‐SCAs.

Design/patients  We reviewed the medical records of all patients who underwent transsphenoidal surgery for NFPAs from January 1990 to October 2007 at the Seoul National University Hospital.

Measurements  We analysed whether clinical manifestations at diagnosis, postoperative recurrence rate and recurrence characteristics differed between SCA and non‐SCA patients.

Results  In total, 28 patients with SCAs and 134 patients with non‐SCAs were analysed. The mean age at the time of diagnosis was 44 years (range, 13–67 years) in the SCA group and 50 years (18–79 years) in the non‐SCA group (P = 0·026), with respective follow‐up periods of 5·2 (range, 1·0–16·0 years) and 4·2 years (0·5–16·1 years) (P = 0·255). Overall recurrence rates of SCAs and non‐SCAs were 25·0% and 26·9% respectively (P = 0·839). More than two recurrences (P = 0·001) and recurrence after more than 5 years (P = 0·040) were associated with SCAs. Multiple recurrences of SCAs were confined to younger patients.

Conclusion  The overall recurrence rate was similar between SCAs and non‐SCAs. However, young patients with SCAs had a higher frequency of multiple and late recurrences, which showed more aggressive tumour behaviour. Therefore, we suggest that patients with SCAs, especially patients diagnosed at a young age, require careful long‐term monitoring.
Enacting language games: the development of a sense of ‘we‐ness’ in online forums
Authors: Fayard Anne‐Laure , DeSanctis Gerardine
Published: July 2009

A sense of ‘we‐ness’– enacted through collective identity and culture – is both crucial in online, remote contexts, and particularly difficult to develop in such settings. Using Wittgenstein's concept of language games, we examine how participants of two online forums construct collective identity and culture through their discursive practices. We suggest a strong performative interpretation of the notion of language games, i.e. members of a community produce a sense of we‐ness through their participation in the language game while also defining their expected behaviours and actions. We illustrate how the notion of language games offers an approach for researching and analysing the emergence of collective identity and culture in online forums.
A simple twist for signal enhancement in non‐linear optical microscopy
Authors: DE A.K. , GOSWAMI D.
Published: July 2009

We describe a very simple but elegant approach to two‐photon fluorescence signal enhancement by intensity modulation with immediate application in two‐photon laser‐scanning fluorescence microscopy. This method of enhancement shows potential application in any microscopic technique that result from non‐linear photon absorption and plays a pivotal role in live cell imaging.
Exploiting advances in imaging technology to study biofilms by applying multiphoton laser scanning microscopy as an imaging and manipulation tool
Authors: LAKINS M.A. , MARRISON J.L. , O’TOOLE P.J. , VAN DER WOUDE M.W.
Published: July 2009

Biofilms are an important element of the natural ecosystems but can be detrimental in health care and industrial settings. To improve our ability to combat biofilms, we need to understand the processes that facilitate their formation and dispersal. One approach that has proven to be invaluable is to image biofilms as they grow. Here we describe tools and protocols to visualize biofilms with multiphoton laser scanning microscopy, compare this with single photon laser scanning confocal microscopy and highlight best working procedures. Furthermore, we describe how with multiphoton laser scanning microscopy the laser can be used to manipulate the biofilm, specifically to achieve localized bleaching, killing or ablation within the biofilm biomass. These applications open novel ways to study the dynamics of biofilm formation, regeneration and dispersal.
Surface plasmon‐enhanced micro‐cylinder mode in photonic quasi‐crystal
Authors: FANG Z.Y. , DAI T. , FU Q. , ZHANG B. , ZHU X.
Published: July 2009

Two‐dimensional micro‐cylinder patterns of dodecagonal photonic quasi‐crystal (12‐PQC) and tetragonal photonic crystal (2‐PC) were fabricated on the top surface of a GaN light‐emitting diode (LED). The patterns were evaporated with a 10‐nm‐thick Ag film. Spatially resolved surface emission was recorded and analysed by scanning near‐field optical microscopy. Electromagnetic energy was confined and enhanced at the top surface when the surface plasmon (SP) resonated. The enhancement factor for 12‐PQC was 1.9 times that of 2‐PC, 8.6 times that of non‐patterned LED in the near field and 6.7 times in the far field, respectively. Finite‐difference time‐domain simulations are consistent with the experimental data. The results show that with a patterned structure on the top surface of an LED, the light emission can be greatly enhanced due to SP resonance.
Using conventional fluorescent markers for far‐field fluorescence localization nanoscopy allows resolution in the 10‐nm range
Authors: LEMMER P. , GUNKEL M. , WEILAND Y. , MÜLLER P. , BADDELEY D. , KAUFMANN R. , URICH A. , EIPEL H. , AMBERGER R. , HAUSMANN M. , CREMER C.
Published: July 2009

We present a novel technique of far‐field localization nanoscopy combining spectral precision distance microscopy with widely used fluorochromes like the Green Fluorescent Protein (GFP) derivatives eGFP, EmGFP, Yellow Fluorescent Protein (YFP) and eYFP, synthetic dyes like Alexa 488 and Alexa 568, as well as fluoresceine derivates. Spectral precision distance microscopy allows the surpassing of conventional resolution limits in fluorescence far‐field microscopy by precise object localization after the optical isolation of single signals in time. Based on the principles of this technique, our novel nanoscopic method was realized for laser optical precision localization and image reconstruction with highly enhanced optical resolution in intact cells. This allows for spatial assignment of individual fluorescent molecules with nanometre precision. The technique is based on excitation intensity dependent reversible photobleaching of the molecules used combined with fast time sequential imaging under appropriate focusing conditions. A meaningful advantage of the technique is the simple applicability as a universal tool for imaging and investigations to the major part of already available preparations according to standard protocols. Using the above mentioned fluorophores, the positions of single molecules within cellular structures were determined by visible light with an estimated localization precision down to 3 nm; hence distances in the range of 10–30 nm were resolved between individual fluorescent molecules allowing to apply different quantitative structure analysis tools.
Fabrication and evaluation of a near‐infrared hyperspectral imaging system
Authors: KATARI S. , WALLACK M. , HUEBSCHMAN M. , PANTANO P. , GARNER H.
Published: July 2009

This paper describes modifications to a hyperspectral imaging microscope that extend its capabilities into the near‐infrared (950–1300 nm). The major changes include installing a grating, charge‐coupled device camera, and lenses and filters appropriate for infrared wavelengths. Calibration of the system and validation with lead sulfide quantum dots of known emission wavelength is reported. Cells from the breast carcinoma cell line SkBr3 were scanned with lead sulfide quantum dots that emit at 1100 nm as the background and an image which contains the integrated spectral data is presented. We also demonstrate that this instrument is capable of detecting the photoluminescence spectra of single‐walled carbon nanotubes dispersed in aqueous solution.
Stereo soft X‐ray microscopy and elemental mapping of haematite and clay suspensions
Authors: GLEBER S.‐C. , THIEME J. , CHAO W. , FISCHER P.
Published: July 2009

The combination of high‐resolution chemically sensitive soft X‐ray microscopy with stereo imaging and processing techniques presented here forms a novel tool for the investigation of aqueous colloidal systems. Information about the spatial distribution within the sample is provided with small calculation effort processing just a pair of stereo micrographs. Thus, the extension towards investigation of dynamical behaviour is possible on the part of the experiment as well as of the processing.

The potential of this technique is demonstrated with applications in aqueous soil and clay samples. Within these samples, haematite particles are identified taking advantage of the elemental contrast at the Fe‐L edge around E= 707 eV. In combination with stereo microscopy, information about spatial arrangements are revealed and correlated to electrostatic interactions of the different mixtures, addressing to an actual question of soil scientists. The technique allows in‐situ sample manipulation, which is demonstrated by a test specimen where particles were added during imaging.
Genome‐wide screens: novel mechanisms in colicin import and cytotoxicity
Authors: Sharma Onkar , Datsenko Kirill A. , Ess Sara C. , Zhalnina Mariya V. , Wanner Barry L. , Cramer William A.
Published: July 2009

Only two new genes (fkpA and lepB) have been identified to be required for colicin cytotoxicity in the last 25 years. Genome‐wide screening using the ‘Keio collection’ to test sensitivity to colicins (col) A, B, D, E1, E2, E3, E7 and N from groups A and B, allowed identification of novel genes affecting cytotoxicity and provided new information on mechanisms of action. The requirement of lipopolysaccharide for colN cytotoxicity resides specifically in the lipopolysaccharide inner‐core and first glucose. ColA cytotoxicity is dependent on gmhB and rffT genes, which function in the biosynthesis of lipopolysaccharide and enterobacterial common antigen. Of the tol genes that function in the cytoplasmic membrane translocon, colE1 requires tolA and tolR but not tolQ for activity. Peptidoglycan‐associated lipoprotein, which interacts with the Tol network, is not required for cytotoxicity of group A colicins. Except for TolQRA, no cytoplasmic membrane protein is essential for cytotoxicity of group A colicins, implying that TolQRA provides the sole pathway for their insertion into/through the cytoplasmic membrane. The periplasmic protease that cleaves between the receptor and catalytic domains of colE7 was not identified, implying either that the responsible gene is essential for cell viability, or that more than one gene product has the necessary proteolysis function.
Replication‐directed sister chromosome alignment in Escherichia coli
Authors: Liu Xun , Wang Xindan , Reyes‐Lamothe Rodrigo , Sherratt David
Published: July 2009

Non‐replicating Escherichia coli chromosomes are organized as sausage‐shaped structures with the left (L) and the right (R) chromosome arms (replichores) on opposite cell halves and the replication origin (oriC) close to midcell. The replication termination region (ter) therefore passes between the two outer edges of the nucleoid. Four alignment patterns of the two  sister chromosomes within a cell have been detected in an asynchronous population, with the  pattern predominating. We test the hypothesis that the minority  and  patterns arise because of pausing of DNA replication on the right and left replichores respectively. The data resulting from transient pausing or longer‐term site‐specific blocking of replication show that paused/blocked loci remain close to midcell and the normally replicated‐segregated loci locate to the outer regions of the nucleoid, therefore providing experimental support for a direct mechanistic link between DNA replication and chromosome organization.
DFNB74, a novel autosomal recessive nonsyndromic hearing impairment locus on chromosome 12q14.2‐q15
Authors: Waryah AM , Rehman A , Ahmed ZM , Bashir Z‐H , Khan SY , Zafar AU , Riazuddin S , Friedman TB , Riazuddin S
Published: July 2009

Autosomal recessive nonsyndromic hearing impairment (ARNSHI) segregating in three unrelated, large consanguineous Pakistani families (PKDF528, PKDF859 and PKDF326) is linked to markers on chromosome 12q14.2‐q15. This novel locus is designated DFNB74. Maximum two‐point limit of detection (LOD) scores of 5.6, 5.7 and 2.6 were estimated for markers D12S313,D12S83 and D12S75 at θ = 0 for recessive deafness segregating in these three families. Haplotype analyses identified a critical linkage interval of 5.35 cM (5.36 Mb) defined by D12S329 at 74.58 cM and D12S313 at 79.93 cM. DFNB74 is the second ARNSHI locus mapped to chromosome 12, but the physical intervals do not overlap with one another. A locus contributing to the early onset, rapidly progressing hearing loss of A/J mice (ahl4, age‐related hearing loss 4) was reported to map to chromosome 10 in a region of conserved synteny to DFNB74, suggesting that ahl4 and DFNB74 may be due to mutations of the same gene in these two species.
Analgesia before a spinal block for femoral neck fracture: fascia iliaca compartment block
Authors: YUN M. J. , KIM Y. H. , HAN M. K. , KIM J. H. , HWANG J. W. , DO S. H.
Published: July 2009

Background: In this prospective randomized study, the authors compared the analgesic effect of a fascia iliaca compartment (FIC) block with that of intravenous (i.v.) alfentanil when administered to facilitate positioning for spinal anaesthesia in elderly patients undergoing surgery for a femoral neck fracture.

Methods: The 40 patients were randomly assigned to one of two groups, namely, the FIC group (fascia iliaca compartment block, n=20) and the IVA group (intravenous analgesia with alfentanil, n=20). Group IVA patients received a bolus dose of i.v. alfentanil 10 μg/kg, followed by a continuous infusion of alfentanil 0.25 μg/kg/min starting 2 min before the spinal block, and group FIC patients received a FIC block with 30 ml of ropivacaine 3.75 mg/ml (112.5 mg) 20 min before the spinal block. Visual analogue pain scale (VAS) scores, time to achieve spinal anaesthesia, quality of patient positioning, and patient acceptance were compared.

Results: VAS scores during positioning (mean and range) were lower in the FIC group than in the IVA group [2.0 (1–4) vs. 3.5 (2–6), P=0.001], and the mean (± SD) time to achieve spinal anaesthesia was shorter in the FIC group (6.9 ± 2.7 min vs. 10.8 ± 5.6 min; P=0.009). Patient acceptance (yes/no) was also better in the FIC group (19/1) than in the IVA group (12/8)(P=0.008).

Conclusions: An FIC block is more efficacious than i.v. alfentanil in terms of facilitating the lateral position for spinal anaesthesia in elderly patients undergoing surgery for femoral neck fractures.
Fatal pneumoperitoneum caused by nasopharyngeal oxygen delivery after transoesophageal echocardiography for cardiac surgery
Authors: MOURISSOUX G. , SCHLUMBERGER S. , DE LENTDECKER P. , FISCHLER M.
Published: July 2009

We report a case of fatal post‐operative pneumoperitoneum in a patient who had undergone urgent mitral valve surgery. In the absence of a proven cause of the pneumoperitoneum (refusal by the family of an autopsy), we can only propose a hypothesis for its origin. The most probable one is that forceful or sustained retrograde flexion of the transoesophageal echocardiographic probe created a lower oesophagus or gastric rupture and that oxygen flow administered by the nasal cannula went straight to the abdominal cavity, leading to tension pneumoperitoneum.
Introduction
Authors: Bertrand Paul P
Published: July 2009

From the Editors‐in‐Chief

This Introduction prefaces three minireviews that are being published under the aegis of our ‘Frontiers in Research’ series. The authors of these reviews recently presented their work at a symposium entitled ‘Inflammation and Innervation of the Intestine’ at the Australian Neuroscience Society meeting in Canberra, 2009. The symposium was supported by the Australian Neuroscience Society, Australasian Neurogastroenterology and Motility Association and this Journal via the present series of minireviews.

Roger Evans and Ding‐Feng Su
Absolute quantification of Dehalococcoides proteins: enzyme bioindicators of chlorinated ethene dehalorespiration
Authors: Werner Jeffrey J. , Ptak A. Celeste , Rahm Brian G. , Zhang Sheng , Richardson Ruth E.
Published: July 2009

The quantification of trace proteins in complex environmental samples and mixed microbial communities would be a valuable monitoring tool in countless applications, including the bioremediation of groundwater contaminated with chlorinated solvents. Measuring the concentrations of specific proteins provides unique information about the activity and physiological state of organisms in a sample. We developed sensitive (< 5 fmol), selective bioindicator assays for the absolute quantification of select proteins used by Dehalococcoides spp. when reducing carbon atoms in the common pollutants trichloroethene (TCE) and tetrachloroethene (PCE). From complex whole‐sample digests of two different dechlorinating mixed communities, we monitored the chromatographic peaks of selected tryptic peptides chosen to represent 19 specific Dehalococcoides proteins. This was accomplished using multiple‐reaction monitoring (MRM) assays using nano‐liquid chromatography‐tandem mass spectrometry (nLC‐MS/MS), which provided the selectivity, sensitivity and reproducibility required to quantify Dehalococcoides proteins in complex samples. We observed reproducible peak areas (average CV = 0.14 over 4 days, n = 3) and linear responses in standard curves (n = 5, R2 > 0.98) using synthetic peptide standards spiked into a background matrix of sediment peptides. We detected and quantified TCE reductive dehalogenase (TceA) at 7.6 ± 1.7 × 103 proteins cell−1 in the KB1TM bioaugmentation culture, previously thought to be lacking TceA. Fragmentation data from MS/MS shotgun proteomics experiments were helpful in developing the MRM targets. Similar shotgun proteomics data are emerging in labs around the world for many environmentally relevant microbial proteins, and these data are a valuable resource for the future development of MRM assays. We expect targeted peptide quantification in environmental samples to be a useful tool in environmental monitoring.
Radiolabelled proteomics to determine differential functioning of Accumulibacter during the anaerobic and aerobic phases of a bioreactor operating for enhanced biological phosphorus removal
Authors: Wexler Margaret , Richardson David J. , Bond Philip L.
Published: July 2009

Proteins synthesized by the mixed microbial community of two sequencing batch reactors run for enhanced biological phosphorus removal (EBPR) during aerobic and anaerobic reactor phases were compared, using mass spectrometry‐based proteomics and radiolabelling. Both sludges were dominated by polyphosphate‐accumulating organisms belonging to Candidatis Accumulibacter and the majority of proteins identified matched closest to these bacteria. Enzymes from the Embden–Meyerhof–Parnas pathway were identified, suggesting this is the major glycolytic pathway for these Accumulibacter populations. Enhanced aerobic synthesis of glyoxylate cycle enzymes suggests this cycle is important during the aerobic phase of EBPR. In one sludge, several TCA cycle enzymes showed enhanced aerobic synthesis, suggesting this cycle is unimportant anaerobically. The second sludge showed enhanced synthesis of TCA cycle enzymes under anaerobic conditions, suggesting full or partial TCA cycle operation anaerobically. A phylogenetic analysis of Accumulibacter polyphosphate kinase genes from each sludge demonstrated different Accumulibacter populations dominated the two sludges. Thus, TCA cycle activity differences may be due to Accumulibacter strain differences. The major fatty acids present in Accumulibacter‐dominated sludge include palmitic, hexadecenoic and cis‐vaccenic acid and fatty acid content increased by approximately 20% during the anaerobic phase. We hypothesize that this is associated with increased anaerobic phospholipid membrane biosynthesis, to accommodate intracellular polyhydroxyalkanoate granules.
Attachment to the Nation and International Relations: Dimensions of Identity and Their Relationship to War and Peace
Authors: Herrmann Richard K. , Isernia Pierangelo , Segatti Paolo
Published: July 2009

Since the rise of mass politics, the role national identities play in international relations has been debated. Do they produce a popular reservoir easily tapped for war or bestow dignity thereby fostering cooperation and a democratic peace? The evidence for either perspective is thin, beset by different conceptions of identity and few efforts to identify its effects independent of situational factors. Using data drawn from new national surveys in Italy and the United States, we advance a three‐dimensional conception of national identity, theoretically connecting the dimensions to conflictive and cooperative dispositions as well as to decisions to cooperate with the United Nations in containing Iran's nuclear proliferation and Sudan's humanitarian crisis in Darfur. Attachment to the nation in Italy and the United States is found to associate with less support for militarist options and more support for international cooperation as liberal nationalists expect. This depends, however, on containing culturally exclusive conceptions of the nation and chauvinism.