bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement Invariance of the Perceived Stress Scale and Latent Mean Differences across Gender and Time
Authors: Barbosa‐Leiker Celestina , Kostick Marylynne , Lei Ming , McPherson Sterling , Roper Virginia , Hoekstra Trynke , Wright Bruce
Published: October 2012

Measurement invariance of the 2‐factor model of the Perceived Stress Scale—10‐item version (Cohen & Williamson, 1988) was tested across men and women at two time points and in the combined total sample over a 2‐year time frame (n = 871). Measurement invariance results indicated that the scale measured the latent factors, stress and counter‐stress, equivalently in men and women and over time. With measurement invariance demonstrated, differences in latent means were tested. Results indicated that men had lower levels of frequencies of stressors, and at one time point, higher levels of counter‐stress, when compared with women. When examining change in frequencies of stressors and counter‐stress over 2 years with the combined male and female sample, stressors remained stable, yet counter‐stress increased over time. These findings may aid in the interpretation of results when examining stressors and counter‐stress in clinical samples where one would expect stress to increase, whereas positive psychological states decrease. Copyright © 2012 John Wiley & Sons, Ltd.
Higgs low-energy theorem (and its corrections) in composite models
Authors: Gillioz M. , Gröber R. , Grojean C. , Mühlleitner M. , Salvioni E.
Published: October 2012

Abstract

The Higgs low-energy theorem gives a simple and elegant way to estimate the couplings of the Higgs boson to massless gluons and photons induced by loops of heavy particles. We extend this theorem to take into account possible nonlinear Higgs interactions as well as new states resulting from a strong dynamics at the origin of the breaking of the electroweak symmetry. We show that, while it approximates with an accuracy of order a few percents single Higgs production, it receives corrections of order 50% for double Higgs production. A full one-loop computation of the gg → hh cross section is explicitly performed in MCHM5, the minimal composite Higgs model based on the SO(5)/SO(4) coset with the Standard Model fermions embedded into the fundamental representation of SO(5). In particular we take into account the contributions of all fermionic resonances, which give sizeable (negative) corrections to the result obtained considering only the Higgs nonlinearities. Constraints from electroweak precision and flavor data on the top partners are analyzed in detail, as well as direct searches at the LHC for these new fermions called to play a crucial role in the electroweak symmetry breaking dynamics.
Functional characterization of novel genotypes and cellular oxidative stress studies in propionic acidemia
Authors: Gallego‐Villar Lorena , Pérez‐Cerdá Celia , Pérez Belén , Abia David , Ugarte Magdalena , Richard Eva , Desviat Lourdes R.
Published: October 2012

Propionic acidemia (PA), caused by a deficiency of the mitochondrial biotin dependent enzyme propionyl‐CoA carboxylase (PCC) is one of the most frequent organic acidurias in humans. PA is caused by mutations in either the PCCA or PCCB genes encoding the α‐ and β‐subunits of the PCC enzyme which are assembled as an α6β6 dodecamer. In this study we have investigated the molecular basis of the defect in ten fibroblast samples from PA patients. Using homology modeling with the recently solved crystal structure of the PCC holoenzyme and a eukaryotic expression system we have analyzed the structural and functional effect of novel point mutations, also revealing a novel splice defect by minigene analysis. In addition, we have investigated the contribution of oxidative stress to cellular damage measuring reactive oxygen species (ROS) levels and apoptosis parameters in patient fibroblasts, as recent studies point to a secondary mitochondrial dysfunction as pathophysiological mechanism in this disorder. The results show an increase in intracellular ROS content compared to controls, correlating with the activation of the JNK and p38 signaling pathways. Highest ROS levels were present in cells harboring functionally null mutations, including one severe missense mutation. This work provides molecular insight into the pathogenicity of PA variants and indicates that oxidative stress may be a major contributing factor to the cellular damage, supporting the proposal of antioxidant strategies as novel supplementary therapy in this rare disease.
Maternal morbidity in early pregnancy in rural northern Bangladesh
Authors: Kim Julia M. , Labrique Alain , West Keith P. , Rashid Mahbubur , Shamim Abu A. , Ali Hasmot , Ullah Barkat , Wu Lee , Massie Allan , Mehra Sucheta , Klemm Rolf , Christian Parul
Published: October 2012

Objective

To determine the burden of maternal morbidity in early pregnancy in rural northern Bangladesh.

Methods

A cross‐sectional analysis was performed on baseline morbidity data from 42 896 pregnant women enrolled in a vitamin A supplementation trial. One‐week histories for 31 defined symptoms were collected at 5–12 weeks of gestation. Ten illnesses were defined, compatible with ICD‐10 diagnoses and WHO definitions. Prevalence, duration, and treatment‐seeking behaviors were determined for each symptom and illness. Risk of wasting malnutrition was compared between symptomatic and asymptomatic women.

Results

In total, 93.1% of women reported at least 1 symptom. The most frequent symptoms were poor appetite (53.3%), vaginal discharge (48.7%), and nausea (48.1%), each of which lasted 22–27 days. The most prevalent illnesses were anemia (36.4%), morning sickness (17.2%), excessive vomiting (7.0%), and reproductive tract infections (6.7%). Symptoms that prompted treatment seeking included jaundice, high‐grade fever, and swelling of hands and face. Odds ratios for malnutrition were higher among women with symptoms of anemia (1.30; 95% confidence interval [CI], 1.24–1.36), vaginal discharge (1.37; 95% CI, 1.31–1.43), and high‐grade fever (1.23; 95% CI, 1.10–1.37) than among those without symptoms.

Conclusion

Women in rural Bangladesh report substantial morbidity in the first trimester.
Three-Dimensional Synchrotron Virtual Paleohistology: A New Insight into the World of Fossil Bone Microstructures
Authors: Sanchez Sophie , Ahlberg Per E. , Trinajstic Katherine M. , Mirone Alessandro , Tafforeau Paul
Published: October 2012

The recent developments of phase-contrast synchrotron imaging techniques have been of great interest for paleontologists, providing three-dimensional (3D) tomographic images of anatomical structures, thereby leading to new paleobiological insights and the discovery of new species. However, until now, it has not been used on features smaller than 5–7 μm voxel size in fossil bones. Because much information is contained within the 3D histological architecture of bone, including an ontogenetic record, crucial for understanding the paleobiology of fossil species, the application of phase-contrast synchrotron tomography to bone at higher resolutions is potentially of great interest. Here we use this technique to provide new 3D insights into the submicron-scale histology of fossil and recent bones, based on the development of new pink-beam configurations, data acquisition strategies, and improved processing tools. Not only do the scans reveal by nondestructive means all of the major features of the histology at a resolution comparable to that of optical microscopy, they provide 3D information that cannot be obtained by any other method.
Strain Measurement in Semiconductor Heterostructures by Scanning Transmission Electron Microscopy
Authors: Müller Knut , Rosenauer Andreas , Schowalter Marco , Zweck Josef , Fritz Rafael , Volz Kerstin
Published: October 2012

This article deals with the measurement of strain in semiconductor heterostructures from convergent beam electron diffraction patterns. In particular, three different algorithms in the field of (circular) pattern recognition are presented that are able to detect diffracted disc positions accurately, from which the strain in growth direction is calculated. Although the three approaches are very different as one is based on edge detection, one on rotational averages, and one on cross correlation with masks, it is found that identical strain profiles result for an InxGa1−xNyAs1−y/GaAs heterostructure consisting of five compressively and tensile strained layers. We achieve a precision of strain measurements of 7–9·10−4 and a spatial resolution of 0.5–0.7 nm over the whole width of the layer stack which was 350 nm. Being already very applicable to strain measurements in contemporary nanostructures, we additionally suggest future hardware and software designs optimized for fast and direct acquisition of strain distributions, motivated by the present studies.
Copper‐nickel‐rich, amalgamated ferromanganese crust‐nodule deposits from Shatsky Rise, NW Pacific
Authors: Hein J. R. , Conrad T. A. , Frank M. , Christl M. , Sager W. W.
Published: October 2012

A unique set of ferromanganese crusts and nodules collected from Shatsky Rise (SR), NW Pacific, were analyzed for mineralogical and chemical compositions, and dated using Be isotopes and cobalt chronometry. The composition of these midlatitude, deep‐water deposits is markedly different from northwest‐equatorial Pacific (PCZ) crusts, where most studies have been conducted. Crusts and nodules on SR formed in close proximity and some nodule deposits were cemented and overgrown by crusts, forming amalgamated deposits. The deep‐water SR crusts are high in Cu, Li, and Th and low in Co, Te, and Tl concentrations compared to PCZ crusts. Thorium concentrations (ppm) are especially striking with a high of 152 (mean 56), compared to PCZ crusts (mean 11). The deep‐water SR crusts show a diagenetic chemical signal, but not a diagenetic mineralogy, which together constrain the redox conditions to early oxic diagenesis. Diagenetic input to crusts is rare, but unequivocal in these deep‐water crusts. Copper, Ni, and Li are strongly enriched in SR deep‐water deposits, but only in layers older than about 3.4 Ma. Diagenetic reactions in the sediment and dissolution of biogenic calcite in the water column are the likely sources of these metals. The highest concentrations of Li are in crust layers that formed near the calcite compensation depth. The onset of Ni, Cu, and Li enrichment in the middle Miocene and cessation at about 3.4 Ma were accompanied by changes in the deep‐water environment, especially composition and flow rates of water masses, and location of the carbonate compensation depth.
Dynamics of energetic electrons in nonstationary quasi‐perpendicular shocks
Authors: Matsukiyo Shuichi , Scholer Manfred
Published: October 2012

A one‐dimensional full particle‐in‐cell (PIC) code is utilized to investigate energetic electron bursts produced at a nonstationary quasi‐perpendicular shock. A number of electrons are intermittently energized by interacting with nonstationary electromagnetic fields in the shock front. Some of the energetic electrons are reflected at the shock and form an upstream non‐thermal population. The reflection process is strongly affected by the non‐coplanar magnetic field component which is temporarily rather strong in the transition region of a highly nonstationary shock. Oblique whistler waves in the transition region influence the distribution function of the reflected electrons. Waves excited by the modified two‐stream instability may pitch angle scatter the electrons and thus blur the loss cone feature of the reflected electrons. Dispersive standing whistler waves are also emitted locally in the foot even when a Mach number exceeds a critical value. These whistler waves may also scatter the electrons to blur the loss cone. Furthermore, the whistler waves produce clumps of the reflected electrons in a phase space. Some electrons are trapped by the ion holes produced downstream as a remnant of a self‐reformation process of the shock front and accelerated through a drift mechanism. It is also discussed how physical quantities associated with the reflected electrons observed upstream of the shock can give information about the shock front nonstationarity as well as about local small scale wave activities in the transition region.
Gyroresonant interactions between the radiation belt electrons and whistler mode chorus waves in the radiation environments of Earth, Jupiter, and Saturn: A comparative study
Authors: Shprits Y. Y. , Menietti J. D. , Gu X. , Kim K. C. , Horne R. B.
Published: October 2012

In the current study we perform a comparative analysis of the gyroresonant interactions of whistler mode waves with radiation belt electrons in the magnetospheres of Earth, Jupiter, and Saturn. Our primary goal is to evaluate the effect of resonant wave‐particle interactions with chorus waves and determine whether chorus waves can produce net acceleration or net loss of radiation belt electrons on the outer planets. The ratio of plasma frequency to gyrofrequency is a key parameter that determines the efficiency of the pitch angle and energy resonant scattering. We present a comparison of statistical maps of the ratio of plasma frequency to gyrofrequency for Jupiter, Saturn and Earth in terms of radial distance and latitude. Preliminary maps of the plasma frequency to gyrofrequency ratio and 2D simulations of pitch angle and energy diffusion using the Versatile Electron Radiation Belt (VERB) indicate that the Kronian plasma environment is not likely to support as efficient gyroresonant interactions with whistler mode chorus waves as in the Terrestrial or Jovian environments. Inefficiency of the local acceleration by whistler mode waves in the Kronian environment raises important questions about the origin of the relativistic electrons in the Saturn's radiation belts. Two‐dimensional diffusive simulations of local acceleration and loss to the atmosphere using the VERB code confirm previous suggestions that the acceleration of electrons may be very efficient in the outer radiation belt of Jupiter. However, sensitivity simulations also show that the result of the competition between acceleration and loss in the Jupiter's magnetosphere strongly depends on the currently unknown latitudinal distribution of chorus waves that will be provided by the upcoming Juno mission. If waves extend to high latitudes, it is likely that the loss rates due to whistler mode waves will exceed energization rates.
Structural basis for TetM-mediated tetracycline resistance
Authors: Dönhöfer Alexandra , Franckenberg Sibylle , Wickles Stephan , Berninghausen Otto , Beckmann Roland , Wilson Daniel N.
Published: October 2012

Ribosome protection proteins (RPPs) confer tetracycline resistance by binding to the ribosome and chasing the drug from its binding site. The current model for the mechanism of action of RPPs proposes that drug release is indirect and achieved via conformational changes within the drug-binding site induced upon binding of the RPP to the ribosome. Here we report a cryo-EM structure of the RPP TetM in complex with the 70S ribosome at 7.2-Å resolution. The structure reveals the contacts of TetM with the ribosome, including interaction between the conserved and functionally critical C-terminal extension of TetM and the decoding center of the small subunit. Moreover, we observe direct interaction between domain IV of TetM and the tetracycline binding site and identify residues critical for conferring tetracycline resistance. A model is presented whereby TetM directly dislodges tetracycline to confer resistance.
The 27–year decline of coral cover on the Great Barrier Reef and its causes
Authors: De’ath Glenn , Fabricius Katharina E. , Sweatman Hugh , Puotinen Marji
Published: October 2012

The world’s coral reefs are being degraded, and the need to reduce local pressures to offset the effects of increasing global pressures is now widely recognized. This study investigates the spatial and temporal dynamics of coral cover, identifies the main drivers of coral mortality, and quantifies the rates of potential recovery of the Great Barrier Reef. Based on the world’s most extensive time series data on reef condition (2,258 surveys of 214 reefs over 1985–2012), we show a major decline in coral cover from 28.0% to 13.8% (0.53% y
−1
), a loss of 50.7% of initial coral cover. Tropical cyclones, coral predation by crown-of-thorns starfish (COTS), and coral bleaching accounted for 48%, 42%, and 10% of the respective estimated losses, amounting to 3.38% y
−1
mortality rate. Importantly, the relatively pristine northern region showed no overall decline. The estimated rate of increase in coral cover in the absence of cyclones, COTS, and bleaching was 2.85% y
−1
, demonstrating substantial capacity for recovery of reefs. In the absence of COTS, coral cover would increase at 0.89% y
−1
, despite ongoing losses due to cyclones and bleaching. Thus, reducing COTS populations, by improving water quality and developing alternative control measures, could prevent further coral decline and improve the outlook for the Great Barrier Reef. Such strategies can, however, only be successful if climatic conditions are stabilized, as losses due to bleaching and cyclones will otherwise increase.
Pathogen-Related Yeast (PRY) proteins and members of the CAP superfamily are secreted sterol-binding proteins
Authors: Choudhary Vineet , Schneiter Roger
Published: October 2012

Sterols and related membrane-perturbing agents are subject to a quality control cycle. Compounds that fail to pass this control are acetylated and secreted into the culture media, whereas lipids that pass the cycle are deacetylated and retained within the cell. Here we describe the identification of a family of conserved proteins, the Pathogen-Related Yeast (PRY) proteins, as a class of sterol-binding proteins.
Saccharomyces cerevisiae
has three members of this family, two of which, Pry1 and Pry2, are secreted, whereas Pry3 is a cell wall–associated protein. Cells lacking both
PRY1
and
PRY2
have a complete block in secretion of the acetylated lipid and Pry1 and Pry2 proteins bind free cholesterol and cholesteryl acetate in vitro. PRY proteins belong to a large protein superfamily of unknown mode of action, the CAP protein superfamily [i.e. cysteine-rich secretory proteins (CRISP), antigen 5, and pathogenesis related 1 proteins]. The conserved CAP domain of Pry1 is necessary and sufficient for lipid export and sterol binding. Expression of a human CAP superfamily member, the cysteine-rich secretory protein 2 (CRISP2), rescues the phenotype of yeast mutants lacking Pry function and purified CRISP2 binds cholesterol in vitro, indicating that lipid binding is a conserved function of the CAP superfamily proteins.
Misconduct accounts for the majority of retracted scientific publications
Authors: Fang Ferric C. , Steen R. Grant , Casadevall Arturo
Published: October 2012

A detailed review of all 2,047 biomedical and life-science research articles indexed by PubMed as retracted on May 3, 2012 revealed that only 21.3% of retractions were attributable to error. In contrast, 67.4% of retractions were attributable to misconduct, including fraud or suspected fraud (43.4%), duplicate publication (14.2%), and plagiarism (9.8%). Incomplete, uninformative or misleading retraction announcements have led to a previous underestimation of the role of fraud in the ongoing retraction epidemic. The percentage of scientific articles retracted because of fraud has increased ∼10-fold since 1975. Retractions exhibit distinctive temporal and geographic patterns that may reveal underlying causes.
Biochemical evidence for superior correction of neuronal storage by chemically modified enzyme in murine mucopolysaccharidosis VII
Authors: Huynh Ha T. , Grubb Jeffrey H. , Vogler Carole , Sly William S.
Published: October 2012

Enzyme replacement therapy has been used successfully in many lysosomal storage diseases. However, correction of brain storage has been limited by the inability of infused enzyme to cross the blood–brain barrier (BBB). We recently reported that PerT-GUS, a form of β-glucuronidase (GUS) chemically modified to eliminate its uptake and clearance by carbohydrate-dependent receptors, crossed the BBB and cleared neuronal storage in an immunotolerant model of murine mucopolysaccharidosis (MPS) type VII. In this respect, the chemically modified enzyme was superior to native β-glucuronidase. Chemically modified enzyme was also delivered more effectively to heart, kidney, and muscle. However, liver and spleen, which express high levels of carbohydrate receptors, received nearly fourfold lower levels of PerT-GUS compared with native GUS. A recent report on PerT-treated sulfamidase in murine MPS IIIA confirmed enhanced delivery to other tissues but failed to observe clearance of storage in neurons. To confirm and extend our original observations, we compared the efficacy of 12 weekly i.v. infusions of PerT-GUS versus native GUS on (
i
) delivery of enzyme to brain; (
ii
) improvement in histopathology; and (
iii
) correction of secondary elevations of other lysosomal enzymes. Such correction is a recognized biomarker for correction of neuronal storage. PerT-GUS was superior to native GUS in all three categories. These results provide additional evidence that long-circulating enzyme, chemically modified to escape carbohydrate-mediated clearance, may offer advantages in treating MPS VII. The relevance of this approach to treat other lysosomal storage diseases that affect brain awaits confirmation.
Genetic analysis of Atlantic salmon captured in a netting station reveals multiple escapement events from commercial fish farms
Authors: Zhang Z. , Glover K. A. , Wennevik V. , Svåsand T. , Sørvik A. G. E. , Fiske P. , Karlsson S. , Skaala Ø.
Published: October 2012

Microsatellite DNA analysis and statistical assignment methods were implemented to identify the origin of 190 farmed escaped Atlantic salmon recaptured over a period of 2 months at a netting station located in Trondheim fjord, Norway. Samples were also collected from farms within the region. The escapees originated from a minimum of two sources, separated in time of capture at the netting station. The majority of the escapees captured in the early period probably originated from a single farm within the region, while escapees captured in later period probably originated from multiple farms, including from outside of the region. Biological data from the escapees supported these conclusions. This study serves to exemplify the use of genetic methods to assist fisheries management.
Effect of activated human polymorphonuclear leucocytes on T lymphocyte proliferation and viability
Authors: Hock Barry D. , Taylor Karen G. , Cross Nicholas B. , Kettle Anthony J. , Hampton Mark B. , McKenzie Judith L.
Published: October 2012

Human polymorphonuclear leucocytes (PMN) are thought to be immunosuppressive. The suppressive mechanism(s) used by PMN are, however, not well defined and in this study they were analysed using T‐cell responses to CD3+ CD28 monoclonal antibodies (mAb) as a readout. We demonstrate that in vitro activated PMN (PMNact) can, without any T‐cell interaction, induce apparent T‐cell suppression by inhibiting the stimulatory capacity of the CD3 mAb. However, a cell‐directed suppression of T‐cell proliferation was observed when PMNact were added to pre‐activated T cells that are already committed to polyclonal proliferation. This suppression was partially reversed by catalase addition (P < 0·01) and largely reversed by addition of exogenous interleukin‐2 (P < 0·001) but was not significantly reduced by nitric oxide synthase inhibition, myeloperoxidase inhibition or addition of excess arginine. Following removal of PMNact, suppressed T cells could respond normally to further stimulation. In addition to suppressing proliferation, co‐culture with PMNact also induced a significant decrease in T‐cell viability that was reversed by catalase addition (P < 0·05). The addition of the arginase inhibitor N‐hydroxy‐nor‐l‐arginine induced both a further significant, catalase‐sensitive, loss in T‐cell viability and increased nitrite release (P < 0·001). These data demonstrate that PMN, when activated, can both induce T‐cell death and reversibly inhibit proliferation of activated T cells. The mechanisms underlying these distinct processes and the effects of arginase inhibitors on PMN induced cytotoxicity merit further investigation.
Homunculus Warping: Conveying importance using self‐intersection‐free non‐homogeneous mesh deformation
Authors: Reinert Bernhard , Ritschel Tobias , Seidel Hans‐Peter
Published: October 2012

Size matters. Human perception most naturally relates relative extent, area or volume to importance, nearness and weight. Reversely, conveying importance of something by depicting it at a different size is a classic artistic principle, in particular when importance varies across a domain. One striking example is the neuronal homunculus; a human figure where the size of each body part is proportional to the neural density on that part. In this work we propose an approach which changes local size of a 2D image or 3D surface and, at the same time, minimizes distortion, prevails smoothness, and, most importantly, avoids fold‐overs (collisions). We employ a parallel, two‐stage optimization process, that scales the shape non‐uniformly according to an interactively‐defined importance map and then solves for a nearby, self‐intersection‐free configuration. The results include an interactive 3D‐rendered version of the classic sensorical homunculus but also a range of images and surfaces with different importance maps.
Word fluency performance and strategies in children with cochlear implants: age‐dependent effects?
Authors: LÖFKVIST ULRIKA , ALMKVIST OVE , LYXELL BJÖRN , TALLBERG ING‐MARI
Published: October 2012

Löfkvist, U., Almkvist, O., Lyxell, B. & Tallberg, I.‐M. (2012). Word fluency performance and strategies in children with cochlear implants: age‐dependent effects? Scandinavian Journal of Psychology 53, 467–474.

Word fluency was examined in 73 Swedish children aged 6–9 years divided into two age groups, 6–7 and 8–9 years; 34 deaf children with cochlear implants (CI) (15 girls/19 boys) and 39 age‐matched children with normal hearing (NH) (20 girls/19 boys). One purpose was to compare the ability to retrieve words in two different word fluency tasks; one phonemically based (FAS letter fluency) and one semantically based (animal fluency). A second purpose was to examine retrieval strategies in the two tasks by conducting an analysis of clustering and switching of word sequences. In general we found that age was an important factor for word fluency ability, in both the CI and the NH groups. It was also demonstrated that children with CI aged 8–9 years retrieved significantly fewer words and used less efficient strategies in the retrieval process, especially on the phonemically based task compared to children with NH of the same ages, whereas children 6–7 years performed similarly in both groups regarding number of retrieved words and use of strategies. The results are discussed with respect to factors such as age differences in performance for children with CI, especially for the phonemically based task.
THE MISSING NARRATIVIST TURN IN THE HISTORIOGRAPHY OF SCIENCE
Authors: KUUKKANEN JOUNI‐MATTI
Published: October 2012

The narrativist turn of the 1970s and 1980s transformed the discussion of general history. With the rejection of Rankean historical realism, the focus shifted to the historian as a narrator and on narratives as literary products. Oddly, the historiography of science took a turn in the opposite direction at the same time. The social turn in the historiography of science emphasized studying science as a material and practical activity with traceable and documentable traits. This empirization of the field has led to an understanding that history of science could be directly describable from scientific practice alone without acknowledging the role of the historian as a constructor of narratives about these practices. Contemporary historians of science tend to be critical of science's ability to describe its object—nature, as it is—but they often are not similarly skeptical of their own abilities to describe their object: past science, as it is. I will argue that historiography of science can only gain from a belated narrativist turn.
Individual dolphins as tools for conservation
Authors: Wells R. S.
Published: October 2012

Read the Feature Paper: The social side of human‐wildlife interaction: wildlife can learn harmful behaviours from each other

Other Commentaries on this paper: Wildlife social learning should inform sustainable tourism management; Conservation issues arising from maladaptive behaviours spreading socially

Response from the authors: Social learning of risky behaviour: importance for impact assessments, conservation and management of human‐wildlife interactions
Wildlife social learning should inform sustainable tourism management
Authors: Higham James E. S.
Published: October 2012

Read the Feature Paper: The social side of human‐wildlife interaction: wildlife can learn harmful behaviours from each other

Other Commentaries on this paper: Individual dolphins as tools for conservation; Conservation issues arising from maladaptive behaviours spreading socially

Response from the authors: Social learning of risky behaviour: importance for impact assessments, conservation and management of human‐wildlife interactions
Migraine: Maladaptive Brain Responses to Stress
Authors: Maleki Nasim , Becerra Lino , Borsook David
Published: October 2012

Migraine offers a unique model to understand the consequences of repeated stressors on the brain. Repeated stressors can alter the normal response of physiological systems, and this concept has been termed “allostatic load.” In the case of the brain, the effects of repeated stress may lead to alteration in brain networks both functionally and structurally. As a result, the brain responds abnormally to environmental conditions (psychological or physiological). Here, we present an alternative perspective on migraine disease and propose that changes in brain states may occur as a result of repeated migraine attacks through maladaptive coping mechanisms. The cascade of these effects can lead to further deterioration of adaptation and thus lead to transformation or chronification of the disease.
In vivo imaging of glia activation using 1H‐magnetic resonance spectroscopy to detect putative biomarkers of tissue epileptogenicity
Authors: Filibian Marta , Frasca Angelisa , Maggioni Daniela , Micotti Edoardo , Vezzani Annamaria , Ravizza Teresa
Published: October 2012

Purpose:  Long‐lasting activation of glia occurs in brain during epileptogenesis, which develops after various central nervous system (CNS) injuries. Glia is the cell source of the biosynthesis and release of molecules that play a role in seizure recurrence and may contribute to epileptogenesis, thus representing a putative biomarker of epilepsy development and severity. In this study, we set up an in vivo longitudinal study using 1H‐magnetic resonance spectroscopy (MRS) to measure metabolite content in the rat hippocampus that could reflect the extent and the duration of glia activation. Our aim was to explore if glia activation during epileptogenesis, or in the chronic epileptic phase, can be used as a biomarker of tissue epileptogenicity (i.e., a measure of epilepsy severity).

Methods:  1H‐MRS measurements were done in the adult rat hippocampus every 24 h for 7 days after status epilepticus (SE) and in chronic epileptic rats, using a 7 T Bruker Biospec MRI (magnetic resonance imaging)/MRS scanner. We studied changes in metabolite levels that reflect astrocytes (myo‐inositol, mIns; glutathione, GSH), microglia/macrophage activation and the associated neuronal cell injury/dysfunction (lactate, Lac; N‐acetyl‐aspartate, NAA). 1H‐MRS results were validated by post hoc immunohistochemistry using cell‐specific markers. Data analysis was done to determine whether correlations exist between the metabolite changes and spontaneous seizure frequency or the extent of neuronal cell loss.

Key Findings:  The analysis of 1H‐MRS spectra showed a progressive increase in mIns and GSH levels after SE, which was maintained in epileptic rats. Lac signal transiently increased during epileptogenesis being undetectable in chronic epileptic tissue. NAA levels were chronically reduced from day 2 post‐SE. Immunohistochemistry confirmed the activation of microglia and astrocytes and the progressive neuronal cell loss. GSH levels during epileptogenesis showed a negative correlation with the frequency of spontaneous seizures, whereas S100β levels in epileptic tissue were positively correlated with this outcome measure. A negative correlation was also found between GSH or mIns levels during epileptogenesis and the extent of neurodegeneration in hippocampus of epileptic rats.

Significance:  1H‐MRS is a valuable in vivo technique for determining the extent and temporal profile of glia activation after an epileptogenic injury. S100β levels measured in the epileptic tissue may represent a biomarker of seizure frequency, whereas GSH levels during epileptogenesis could serve as a predictive marker of seizure frequency. Both mIns and GSH levels measured before the onset of spontaneous seizures predict the extent of neuronal cell loss in epileptic tissue. These findings highlight the potential of serial 1H‐MRS analysis for searching epilepsy biomarkers for prognostic, diagnostic, or therapeutic purposes.
Interictal PET and ictal subtraction SPECT: Sensitivity in the detection of seizure foci in patients with medically intractable epilepsy
Authors: Desai Atman , Bekelis Kimon , Thadani Vijay M. , Roberts David W. , Jobst Barbara C. , Duhaime Ann‐Christine , Gilbert Karen , Darcey Terrance M. , Studholme Colin , Siegel Alan
Published: October 2012

Purpose: Interictal positron emission tomography (PET) and ictal subtraction single photon emission computed tomography (SPECT) of the brain have been shown to be valuable tests in the presurgical evaluation of epilepsy. To determine the relative utility of these methods in the localization of seizure foci, we compared interictal PET and ictal subtraction SPECT to subdural and depth electrode recordings in patients with medically intractable epilepsy.

Methods: Between 2003 and 2009, clinical information on all patients at our institution undergoing intracranial electroencephalography (EEG) monitoring was charted in a prospectively recorded database. Patients who underwent preoperative interictal PET and ictal subtraction SPECT were selected from this database. Patient characteristics and the findings on preoperative interictal PET and ictal subtraction SPECT were analyzed. Sensitivity of detection of seizure foci for each modality, as compared to intracranial EEG monitoring, was calculated.

Key Findings: Fifty‐three patients underwent intracranial EEG monitoring with preoperative interictal PET and ictal subtraction SPECT scans. The average patient age was 32.7 years (median 32 years, range 1–60 years). Twenty‐seven patients had findings of reduced metabolism on interictal PET scan, whereas all 53 patients studied demonstrated a region of relative hyperperfusion on ictal subtraction SPECT suggestive of an epileptogenic zone. Intracranial EEG monitoring identified a single seizure focus in 45 patients, with 39 eventually undergoing resective surgery. Of the 45 patients in whom a seizure focus was localized, PET scan identified the same region in 25 cases (56% sensitivity) and SPECT in 39 cases (87% sensitivity). Intracranial EEG was concordant with at least one study in 41 cases (91%) and both studies in 23 cases (51%). In 16 (80%) of 20 cases where PET did not correlate with intracranial EEG, the SPECT study was concordant. Conversely, PET and intracranial EEG were concordant in two (33%) of the six cases where the SPECT did not demonstrate the seizure focus outlined by intracranial EEG. Thirty‐three patients had surgical resection and >2 years of follow‐up, and 21 of these (64%) had Engel class 1 outcome. No significant effect of imaging concordance on seizure outcome was seen.

Significance: Interictal PET and ictal subtraction SPECT studies can provide important information in the preoperative evaluation of medically intractable epilepsy. Of the two studies, ictal subtraction SPECT appears to be the more sensitive. When both studies are used together, however, they can provide complementary information.
Demography of a carnivore, the red fox, Vulpes vulpes: what have we learnt from 70 years of published studies?
Authors: Devenish‐Nelson Eleanor S. , Harris Stephen , Soulsbury Carl D. , Richards Shane A. , Stephens Philip A.
Published: October 2012

Populations of the same species often face different selection pressures and, increasingly, the demography of populations within a species has been shown to be highly variable. Knowledge of such intraspecific differences has implications for substituting demographic data, a practice that is often necessary for population modelling due to missing parameters. The red fox Vulpes vulpes, a widely‐studied, widespread and economically important species, offers an opportunity to consider the degree of intraspecific variability in the demography of a carnivore and to test the consequences of interpopulation data substitution. We use published life history data to review the extent and quality of demographic data for fox populations. Using demographic descriptors, matrix models, and perturbation analyses, we identify important demographic properties and classify interpopulation variation along the fast–slow continuum. We also illustrate the consequences of data substitution in demographic models. Data quality varies substantially between reviewed studies. Sufficient data exist to model the demography of eight of 56 study populations. Modelled populations have a tendency towards positive population growth, with survival and fecundity of the youngest age class contributing most to that growth. Metrics point to strategies ranging from medium to fast life histories. While broad demographic similarities exist among fox populations, our results imply considerable demographic variation between populations. We show that significant differences in model outcomes based on substituted data are dependent on the parameter replaced, and that geographic proximity does not imply demographic similarity. Superficially, the red fox appears to have been well studied, yet there are remarkably few usable demographic data from much of its range. Despite 70 years of published studies, we were unable to examine the effects on demographic parameters of harvesting regimes, density and weather. We propose improvements to enhance the value of demographic data, both for foxes and for other species.
The influence of abundance on detectability
Authors: McCarthy Michael A. , Moore Joslin L. , Morris William K. , Parris Kirsten M. , Garrard Georgia E. , Vesk Peter A. , Rumpff Libby , Giljohann Kate M. , Camac James S. , Bau S. Sana , Friend Tessa , Harrison Barnabas , Yue Benita
Published: October 2012

Plant and animal survey detection rates are important for ecological surveys, environmental impact assessment, invasive species monitoring, and modeling species distributions. Species can be difficult to detect when rare but, in general, how detection probabilities vary with abundance is unknown. We developed a new detectability model based on the time to detection of the first individual of a species. Based on this model, the predicted detection rate is proportional to a power function of abundance with a scaling exponent between zero and one that depends on clustering of individuals. We estimated the model parameters with data from three independent datasets: searches for chenopod shrub species and coins, experimental searches for planted seedlings, and frog surveys at multiple sites in sub‐tropical forests of eastern Australia. Analyses based on the detection time and detection probability suggest that detection rate increases with abundance as predicted. The model provides a way to scale detection rates to cases of low abundance when direct estimation of detection rates is often impractical.
Research on Mediator Style: A Summary and Some Research Suggestions
Authors: Wall James , Kressel Kenneth
Published: October 2012

Empirical research on mediator style, after promising beginnings, has not kept pace with the significant and continuing interest of mediation practitioners in mediator stylistic behavior and thinking. In the hopes of closing the research‐practice gap, we consider the practical and conceptual importance of conducting research on mediator style. We then present an overview of what is known empirically about mediator stylistic behavior, with an emphasis on the research papers in this volume. Those papers address three major issues: (a) What mediators say about their stylistic preferences; (b) the degree to which mediators show stylistically flexibility; and (c) the relative impact of mediator style on the process and outcomes of mediation. We thenconsider why the empirical record on mediator style is still relatively weak, and we offer suggestions for moving forward along more vigorous research lines.
Phase IV study comparing incobotulinumtoxinA and onabotulinumtoxinA using a 1:1.5 dose‐conversion ratio for the treatment of glabellar frown lines
Authors: Prager Welf , Rappl Thomas
Published: October 2012

Background

IncobotulinumtoxinA and onabotulinumtoxinA are effective treatments for glabellar frown lines, and a dose of 20 U is recommended for both preparations. However, debate continues over using the same dosages of these products, although a 1:1 dose ratio has been proven in several head‐to‐head clinical trials in neurological and esthetic indications.

Objectives

To investigate whether a 50% higher dose of onabotulinumtoxinA was nonsuperior to incobotulinumtoxinA in the treatment of glabellar frown lines in the short and long term.

Methods and materials

Subjects aged 18–65 years with symmetrical moderate‐to‐severe glabellar frown lines (score: ≥2 on a validated Merz 5‐point scale) at maximum frown were enrolled. Corrugator muscles on both sides were treated with two injections of either 4 U incobotulinumtoxinA or 6 U onabotulinumtoxinA (equivalent to 20 and 30 U, respectively, if corrugator muscles on both sides and the procerus are treated) allowing intra‐individual comparison. Glabellar frown line severity was assessed from standardized photographs every 4 weeks for 4 months and, in a subset of subjects, for up to 6 months posttreatment. The primary efficacy endpoint was the percentage of subjects with an improvement of ≥1 point on the 5‐point scale at week 4. Nonsuperiority was assessed by comparing the response rates of each product.

Results

Nonsuperiority of a 50% higher dose of onabotulinumtoxinA to that of incobotulinumtoxinA was confirmed at 4 weeks, 4 months, and 6 months posttreatment.

Conclusion

There is generally no reason to increase the dose of either incobotulinumtoxinA or onabotulinumtoxinA above the 20 U recommended for glabellar frown lines.
Adenylate Kinase Release as a High-Throughput-Screening-Compatible Reporter of Bacterial Lysis for Identification of Antibacterial Agents
Authors: Jacobs Anna C. , DiDone Louis , Jobson Jennielle , Sofia Madeline K. , Krysan Damian , Dunman Paul M.
Published: October 2012

Adenylate kinase (AK) is a ubiquitous intracellular enzyme that is released into the extracellular space upon cell lysis. We have shown that AK release serves as a useful reporter of bactericidal agent activity and can be exploited for antimicrobial screening purposes. The AK assay exhibits improved sensitivity over that of growth-based assays and can detect agents that are active against bacteria in clinically relevant growth states that are difficult to screen using conventional approaches, such as small colony variants (SCV) and bacteria within established biofilms. The usefulness of the AK assay was validated by screening a library of off-patent drugs for agents that exhibit antimicrobial properties toward a variety of bacterial species, including
Escherichia coli
and all members of the “ESKAPE” pathogens (E
nterococcus faecium
, S
taphylococcus aureus
, K
lebsiella pneumoniae
, A
cinetobacter baumannii
, P
seudomonas aeruginosa
, and E
nterobacter
species). The assay detected antibiotics within the library that were expected to be active against the organism screened. Moreover, 38 drugs with no previously reported antibacterial activity elicited AK release. Four of these were acquired, and all were verified to exhibit antimicrobial activity by standard susceptibility testing. Two of these molecules were further characterized. The antihistamine, terfenadine, was active against
S. aureus
planktonic, SCV population, and biofilm-associated cells. Tamoxifen, an estrogen receptor antagonist, was active toward
E. faecium
in vitro
and also reduced
E. faecium
pathogenesis in a
Galleria mellonella
infection model. Our data demonstrate that the AK assay provides an attractive screening approach for identifying new antimicrobial agents. Further, terfenadine and tamoxifen may represent novel antimicrobial drug development scaffolds.
Thiol Peroxidase Is an Important Component of Streptococcus pneumoniae in Oxygenated Environments
Authors: Hajaj Barak , Yesilkaya Hasan , Benisty Rachel , David Maayan , Andrew Peter W. , Porat Nurith
Published: October 2012

Streptococcus pneumoniae
is an aerotolerant Gram-positive bacterium that causes an array of diseases, including pneumonia, otitis media, and meningitis. During aerobic growth,
S. pneumoniae
produces high levels of H
2
O
2
. Since
S. pneumoniae
lacks catalase, the question of how it controls H
2
O
2
levels is of critical importance. The
psa
locus encodes an ABC Mn
2+
-permease complex (
psaBCA
) and a putative thiol peroxidase,
tpxD
. This study shows that
tpxD
encodes a functional thiol peroxidase involved in the adjustment of H
2
O
2
homeostasis in the cell. Kinetic experiments showed that recombinant TpxD removed H
2
O
2
efficiently. However,
in vivo
experiments revealed that TpxD detoxifies only a fraction of the H
2
O
2
generated by the pneumococcus. Mass spectrometry analysis demonstrated that TpxD Cys
58
undergoes selective oxidation
in vivo
, under conditions where H
2
O
2
is formed, confirming the thiol peroxidase activity. Levels of TpxD expression and synthesis
in vitro
were significantly increased in cells grown under aerobic versus anaerobic conditions. The challenge with D39 and TIGR4 with H
2
O
2
resulted in
tpxD
upregulation, while
psaBCA
expression was oppositely affected. However, the challenge of Δ
tpxD
mutants with H
2
O
2
did not affect
psaBCA
, implying that TpxD is involved in the regulation of the
psa
operon, in addition to its scavenging activity. Virulence studies demonstrated a notable difference in the survival time of mice infected intranasally with D39 compared to that of mice infected intranasally with D39Δ
tpxD
. However, when bacteria were administered directly into the blood, this difference disappeared. The findings of this study suggest that TpxD constitutes a component of the organism's fundamental strategy to fine-tune cellular processes in response to H
2
O
2
.
Novel use of optical coherence tomography
Authors: Patel Indravadan J , Bezerra Hiram G , Costa Marco A , Fujino Yusuke , Hsu Daniel P
Published: October 2012

Currently in use by interventional cardiology for the intravascular evaluation of coronary arteries, optical coherence tomography (OCT) has proven to be effective in the evaluation of atherosclerotic disease and further therapeutic management. We report a novel use of OCT technology in the case of a 46-year-old man with sudden onset blurred vision and greater than 70% stenosis of his left vertebral artery. To date, no detailed descriptions or case reports have previously been reported regarding the use of neuroendovascular OCT in diseased arteries.