bluuebunny/crossref_metadata_2025 huggingface dataset:
Using dissociation energies to predict observability of b‐ and y‐peaks in mass spectra of short peptides. II. Results for hexapeptides with non‐polar side chains
Authors: Obolensky O. I. , Wu Wells W. , Shen Rong‐Fong , Yu Yi‐Kuo
Published: December 2012

RATIONALE

The hypothesis that dissociation energies can serve as a predictor of observability of b‐ and y‐peaks is tested for seven hexapeptides. If the hypothesis holds true for large classes of peptides, one would be able to improve the scoring accuracy of peptide identification tools by excluding theoretical peaks that cannot be observed in practical product ion spectra due to various physical, chemical or thermodynamic considerations.

METHODS

Product ion m/z spectra of hexapeptides AAAAAA, AAAFAA, AAAVAA, AAFAAA, AAVAAA, AAFFAA and AAVVAA have been acquired on a Finnigan LTQ XL mass spectrometer in the collision‐induced dissociation (CID) activation mode on a grid of activation times 0.05 to 100 ms and normalized collision energy 10 to 35%. Dissociation energies were calculated for all fragmentation channels leading to b‐ and y‐fragments at the TPSS/6‐31G(d,p) level of the density functional theory.

RESULTS

It was demonstrated that the m/z peaks observed in the product ion spectra correspond to the fragmentation channels with dissociation energies below a certain threshold value. However, there is no direct correlation between the most intense m/z peaks and the lowest dissociation energies. Using the dissociation energies, it was predicted that out of 63 theoretically possible peaks in the b‐ and y‐series of the seven hexapeptides, 19 should not be observable in practical spectra. In the experiments, 24 peaks were not observed, including all 19 predicted.

CONCLUSIONS

Dissociation energies alone are not sufficient for predicting ion intensity relationships in product ion m/z spectra. Nevertheless, the present data suggest that dissociation energies appear to be good predictors of observability of b‐ and y‐peaks and potentially very useful for filtering theoretical peaks of each candidate peptide in peptide identification tools. Published 2012. This article is a US Government work and is in the public domain in the USA.
Abundant naphthenic acids in oil sands process‐affected water: studies by synthesis, derivatisation and two‐dimensional gas chromatography/high‐resolution mass spectrometry
Authors: West Charles E. , Scarlett Alan G. , Pureveen Jos , Tegelaar Erik W. , Rowland Steven J.
Published: December 2012

RATIONALE

The large volumes of 'supercomplex' mixtures of reputedly toxic organic compounds in acidic extracts of oil sands process‐affected waters (OSPW) represent a challenging goal for complete characterisation. To date, comprehensive two‐dimensional gas chromatography/time‐of‐flight mass spectrometry (GCxGC/TOFMS) has allowed the acquisition and interpretation of numerous electron ionisation mass spectra including many of those confirmed to be tricyclic and pentacyclic carboxylic acids by reference to the spectra and retention positions of authentic or synthetic compounds. This has allowed the toxicities of some of the identified acids to be determined and their environmental significance to be better assessed.

METHODS

Synthesis, derivatisation (methyl, trideuteriomethyl and trimethylsilyl esters) and GCxGC/TOFMS with nominal mass and higher mass accuracy (ca. 5 ppm) were used to study three abundant unknown acids present in OSPW samples from two different industrial suppliers.

RESULTS

GCxGC/TOFMS with nominal mass accuracy, of methyl, trideuteriomethyl and trimethylsilyl esters of three abundant acids in two OSPW samples, produced mass spectra consistent with their assignment as either C16 tetracyclic acids or as isobaric pentacyclic C15 hydroxy acids ('O3') or sulfur‐containing ('SO2') species. The synthesis of several isomeric pentacyclic C15 hydroxy acids and examination of the GCxGC retention times and mass spectra (nominal mass) of their derivatives suggested that the unknown OSPW acids were not hydroxy acids, and GCxGC/TOFMS with higher mass accuracy ruled out the possibility. The possibility that they were isobaric 'SO2' species could also be dismissed as this was inconsistent with accurate masses, the derivatisation reactions observed, the fragmentation patterns and the isotope distributions, which excluded the presence of sulphur.

CONCLUSIONS

The data support the contention that the three abundant unknowns were indeed C16 tetracyclic acids. An equally rigorous approach will be necessary to characterise further acids in such mixtures. This is important so that chemistry can be used to guide the search for toxic modes of action. Copyright © 2012 John Wiley & Sons, Ltd.
Evaluation of the interrelationship between mass resolving power and mass error tolerances for targeted bioanalysis using liquid chromatography coupled to high‐resolution mass spectrometry
Authors: Kaufmann A. , Walker S.
Published: December 2012

The determination of acceptable mass error tolerances for high‐resolution mass spectrometry based signals has been evaluated in a comprehensive way. This was achieved by using a technical approach which is based on the post‐column infusion of an analyte containing solution. This well‐known experimental setup was not used to spot signal suppression regions of a particular analyte, but to spot regions of the chromatogram where a systematic mass drift of the analyte ion can be observed (isobaric interference plot). Not the changing signal intensity but the stability of the measured analyte mass was observed. A wide range of different analytes in combinations with potentially interfering matrices has been evaluated. Furthermore, different mass resolving power settings were evaluated. Isobaric interferences between matrix compounds and analytes were common at mass resolving powers <50 000 full width at half maximum. The proposed post‐column infusion technique is a useful tool for the determination of the assay and matrix‐specific mass error tolerances. It aims to ensure the highest possible selectivity, at the same time preventing the encounter of detrimental mass error related peak deformations as well as false negative findings. Unlike conventional matrix spiking approaches, isobaric interference plots provide information of potential interferences across the whole chromatographic time range. This becomes relevant when there is a relative retention time shift between the analyte and potential interfering matrix compounds. Furthermore, the described setup can be used to study how the mass accuracy of any mass spectrometer is affected by a widely varying total ion current. Copyright © 2012 John Wiley & Sons, Ltd.
Autonomous GPR Surveys using the Polar Rover Yeti
Authors: Lever J. H. , Delaney A. J. , Ray L. E , Trautmann E. , Barna L. A. , Burzynski A. M
Published: December 2012

The National Science Foundation operates stations on the ice sheets of Antarctica and Greenland to investigate Earth's climate history, life in extreme environments, and the evolution of the cosmos. Understandably, logistics costs predominate budgets due to the remote locations and harsh environments involved. Currently, manual ground‐penetrating radar (GPR) surveys must preceed vehicle travel across polar ice sheets to detect subsurface crevasses or other voids. This exposes the crew to the risks of undetected hazards. We have developed an autonomous rover, Yeti, specifically to conduct GPR surveys across polar ice sheets. It is a simple four‐wheel‐drive, battery‐powered vehicle that executes autonomous surveys via GPS waypoint following. We describe here three recent Yeti deployments, two in Antarctica and one in Greenland. Our key objective was to demonstrate the operational value of a rover to locate subsurface hazards. Yeti operated reliably at −30 °C, and it has has good oversnow mobility and adequate GPS accuracy for waypoint‐following and hazard georeferencing. It has acquired data on hundreds of crevasse encounters to improve our understanding of heavily crevassed traverse routes and to develop automated crevasse‐detection algorithms. Importantly, it helped to locate a previously undetected buried building at the South Pole. Yeti can improve safety by decoupling survey personnel from the consequences of undetected hazards. It also enables higher‐quality systematic surveys to improve hazard‐detection probabilities, increase assessment confidence, and build datasets to understand the evolution of these regions. Yeti has demonstrated that autonomous vehicles have great potential to improve the safety and efficiency of polar logistics. © 2012 Wiley Periodicals, Inc.
Red‐Emitting Upconverting Nanoparticles for Photodynamic Therapy in Cancer Cells Under Near‐Infrared Excitation
Authors: Tian Gan , Ren Wenlu , Yan Liang , Jian Shan , Gu Zhanjun , Zhou Liangjun , Jin Shan , Yin Wenyan , Li Shoujian , Zhao Yuliang
Published: December 2012

Upconverting nanoparticles (UCNPs) have attracted considerable attention as potential photosensitizer carriers for photodynamic therapy (PDT) in deep tissues. In this work, a new and efficient NIR photosensitizing nanoplatform for PDT based on red‐emitting UCNPs is designed. The red emission band matches well with the efficient absorption bands of the widely used commercially available photosensitizers (Ps), benefiting the fluorescence resonance energy transfer (FRET) from UCNPs to the attached photosensitizers and thus efficiently activating them to generate cytotoxic singlet oxygen. Three commonly used photosensitizers, including chlorine e6 (Ce6), zinc phthalocyanine (ZnPc) and methylene blue (MB), are loaded onto the alpha‐cyclodextrin‐modified UCNPs to form Ps@UCNPs complexes that efficiently produce singlet oxygen to kill cancer cells under 980 nm near‐infrared excitation. Moreover, two different kinds of drugs are co‐loaded onto these nanoparticles: chemotherapy drug doxorubicin and PDT agent Ce6. The combinational therapy based on doxorubicin (DOX)‐induced chemotherapy and Ce6‐triggered PDT exhibits higher therapeutic efficacy relative to the individual means for cancer therapy in vitro.
Socially Sustainable Work Organisations: A Debate
Authors: Kira Mari , van Eijnatten Frans M.
Published: December 2012

This is our third Research Note belonging to an ongoing debate in Systems Research and Behavioral Science about socially sustainable work organisations and systems approaches in their creation. In the Research Note, we provide a history of the debate and summarise some of its key points. Copyright © 2012 John Wiley & Sons, Ltd.
Poly(A) binding proteins: are they all created equal?
Authors: Goss Dixie J. , Kleiman Frida Esther
Published: December 2012

The PABP family of proteins were originally thought of as a simple shield for the mRNA poly(A) tail. Years of research have shown that PABPs interact not only with the poly(A) tail, but also with specific sequences in the mRNA, having a general and specific role on the metabolism of different mRNAs. The complexity of PABPs function is increased by the interactions of PABPs with factors involved in different cellular functions. PABPs participate in all the metabolic pathways of the mRNA: polyadenylation/deadenylation, mRNA export, mRNA surveillance, translation, mRNA degradation, microRNA‐associated regulation, and regulation of expression during development. In this review, we update information on the roles of PABPs and emerging data on the specific interactions of PABP homologs. Specific functions of individual members of PABPC family in development and viral infection are beginning to be elucidated. However, the interactions are complex and recent evidence for exchange of nuclear and cytoplasmic forms of the proteins, as well as post‐translational modifications, emphasize the possibilities for fine‐tuning the PABP metabolic network. WIREs RNA 2013, 4:167–179. doi: 10.1002/wrna.1151

This article is categorized under:

RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications

Translation > Translation Regulation

RNA Processing > 3' End Processing
In situ Synthesis, Crystal Structures, and Characterization of Three Milrinone Tetrazolyl Complexes
Authors: Tang Yun‐Zhi , Huang Jun , Zhou Man , Wu Ji‐Si , Tan Yu‐Hui , Wen He‐Rui
Published: December 2012

Abstract. In situ [2+3] cycloaddition reactions of milrinone [= 3‐cyano‐6‐methyl‐5‐(4‐pyridyl)‐2‐pyridone] with sodium azide in the presence of MnCl2·4H2O, FeSO4·7H2O, or CoCl2·6H2O as Lewis acids, gave three new complexes {[Mn(Mitz)2(H2O)2]·(H2O)} (1), {[Fe(Mitz)2(H2O)2]·(H2O)} (2), and {[Co(Mitz)2(H2O)2]·(H2O)} (3) [Mitz = 3‐tetrazole‐6‐methyl‐5‐(4‐pyridyl)‐2‐pyridone]. All the complexes were characterized by elemental analysis, IR spectroscopy, single‐crystal X‐ray diffraction analysis, X‐ray powder diffraction, and thermogravimetric analysis. X‐ray diffraction analyses show that complexes 1–3 have isomorphous structures. The central metal atoms in these complexes are hexacoordinated and connected by two water molecules, two nitrogen atoms from different tetrazolyl groups, and two oxygen atoms from carbonyl functions respectively. The fluorescent emission spectrum of 1 in the solid‐state at room temperature shows a maximal emission peak at 365 nm.
Merging meets matching in MC@NLO
Authors: Frederix Rikkert , Frixione Stefano
Published: December 2012

Abstract

The next-to-leading order accuracy for MC@NLO results exclusive in J light jets is achieved if the computation is based on matrix elements that feature J and J + 1 QCD partons. The simultaneous prediction of observables which are exclusive in different light-jet multiplicities cannot simply be obtained by summing the above results over the relevant range in J; rather, a suitable merging procedure must be defined. We address the problem of such a merging, and propose a solution that can be easily incorporated into existing MC@NLO implementations. We use the automated aMC@NLO framework to illustrate how the method works in practice, by considering the production at the 8 TeV LHC of a Standard Model Higgs in association with up to J = 2 jets, and of an e
+
ν

e
pair or a
$ t\overline{t} $
pair in association with up to J = 1 jet.
Platelet‐Rich Plasma as a Nonsurgical Treatment Option for Osteonecrosis
Authors: Ibrahim Victor , Dowling Heather
Published: December 2012

Avascular necrosis (AVN) is a progressive condition characterized by bone tissue cell death as a result of ischemia, which is most often seen in weight‐bearing joints. The traditional treatment of this disease process in the hip includes surgical decompression and joint replacement. This case report describes a novel nonsurgical approach for treating advanced‐stage degenerative AVN of the hip with the use of autologous platelet‐rich plasma. The patient demonstrated significant functional improvements after this intervention without the need for further treatment except for physical therapy. The report suggests the potential utility of platelet‐rich plasma for the treatment of degenerative AVN.
Exertional Leg Pain in the Athlete
Authors: Rajasekaran Sathish , Kvinlaug Kylie , Finnoff Jonathan T.
Published: December 2012

Exertional leg pain is a common condition seen in athletes and the general population. Although the differential diagnosis of exertional leg pain is broad, this article focuses on the incidence, anatomy, pathophysiology, clinical presentation, diagnostic evaluation, management, and return‐to‐play guidelines of chronic exertional compartment syndrome and vascular and nerve entrapment etiologies.
Paleoenvironmental reconstruction of the early Neolithic to middle Bronze Age Peña Larga rock shelter (Álava, Spain) from the small mammal record
Authors: Rofes Juan , Zuluaga Mari Cruz , Murelaga Xabier , Fernández-Eraso Javier , Bailon Salvador , Iriarte María José , Ortega Luis Ángel , Alonso-Olazabal Ainhoa
Published: December 2012

The Peña Larga site, a rock shelter on the southern slopes of the Cantabrian cordillera (north Spain), is an archeological deposit covering nearly 4000 years, from the early Neolithic to the middle Bronze Age (Atlantic/Subboreal chronozones). It was used both as a household and as a stable, with a hiatus in the Chalcolithic when it was used as a collective sepulcher. Nearly twenty-eight thousand small vertebrate elements were recovered from its seven stratigraphic units, of which 2553 items were identified to the genus and/or species levels. The assemblage is composed of mammals, birds, reptiles, and amphibians. Of these, small mammals were used for paleoenvironmental reconstruction since they are very sensitive to climatic conditions, the sample sizes are large, and their preservation is good. Their distributions over time, measured in terms of relative abundance, serve as reliable proxies of habitat and climate change. The reconstruction of Peña Larga's past environments based on small mammals roughly coincides with the pollen and the amphibian/reptile records on the local scale, and with that of an ice core from Central Greenland on the global scale. This makes it a valuable tool for comparative purposes both in the regional and continental scales.
Political Investment: Remittances and Elections
Authors: O'Mahony Angela
Published: December 2012

Elections, the defining feature of representative democracy, are generally considered domestic matters. However, elections are increasingly influenced by and conducted on the international stage, and migrants have become increasingly important political actors in home country elections. This article analyses the relationship between migrants’ remittances and elections in their countries of origin, and argues that migrants’ decisions to remit reflect their home countries’ electoral calendars and political context. An analysis of remittance flows to eighty-one developing countries, 1990–2005, provides systematic evidence for the existence of political remittance cycles. Remittances increase in election years, an effect that is larger the more contested the election and the poorer the home country, suggesting an understudied link between developing countries’ domestic politics and their citizens living abroad.
Impromptu Speaking
Authors: Hudson-Williams H. LL.
Published: December 2012

A Striking development in recent years has been the rapidly increasing popularity of extempore addresses and discussions of various kinds. Although by no means confined to broadcasting, these are particularly prominent in the programmes of the B.B.C. Well-known men and women deliver impromptu speeches or improvise answers to questions on various points of political, ethical, social, literary, or scientific interest. Their audiences are generally large and appreciative, far larger than those commanded by the lecturer who has carefully prepared beforehand the substance and style of his address.

This cult of the impromptu speech has a close parallel in Greece of the sophistic era. A prominent member of the ‘Brains Trust’ in ancient Greece, had one existed, would undoubtedly have been Hippias of Elis. Aided by his vast knowledge, covering, it would seem, every branch of human activity, he used to appear before large audiences, such as the great Panhellenic Festival at Olympia, claiming to answer any question his hearers might put to him. He apparently fulfilled his promise, for he told Socrates that no one had yet got the better of him. However, his system of improvising answers broke down when confronted by Socrates’ inexorable cross-questioning on the nature of Beauty, and he had to ask Socrates for a few moments’ grace in order to think the question over quietly by himself.

A close rival of Hippias for ‘Brains Trust’ honours would have been Gorgias of Leontini. He, also, used to appear before large audiences professing his readiness to answer any questions, and once told Socrates it was many years since anyone had asked him anything new.
Reconstructing phonological change: duration and syllable structure in Latin vowel reduction
Authors: Sen Ranjan
Published: December 2012

During the fixed initial-stress period of Latin (sixth to fifth centuries BC), internal open syllable vowels were totally neutralised, usually raising to /i/ (*per.fa.ki.oː>perficiō‘I complete’), whereas in closed syllables /a/ was raised to /e/, but the other vowels remained distinct (*per.fak.tos>perfectus‘completed’). Miller (1972) explains closed syllable resistance by positing internal secondary stress on closed syllables. However, evidence from vowel reduction and syncope suggest that internal syllables never bore stress in early archaic times. A typologically unusual alternative is proposed: contrary to the pattern normally found (Maddieson 1985), vowels had longer duration in closed syllables than in open syllables, as in Turkish and Finnish, thus permitting speakers to attain the targets for non-high vowels in closed syllables. This durational pattern is manifested not only in vowel reduction, but also in the quantitative changes seen in ‘classical’ and ‘inverse’ compensatory lengthenings, the development CVːCV > CVC and ‘superheavy’ degemination (VːCCV > VːCV).
The Sacramental Significance of the Coronation
Authors: Nazir-Ali Michael
Published: December 2012

The Queen remains in robust health but, inevitably, as she gets older there is speculation about the form and content of the next coronation service, whenever it may be needed.
Nutrient intakes from complementary foods consumed by young children (aged 12–23 months) from North Wollo, northern Ethiopia: the need for agro-ecologically adapted interventions
Authors: Baye Kaleab , Guyot Jean-Pierre , Icard-Vernière Christèle , Mouquet-Rivier Claire
Published: December 2012

Objective

To characterize current feeding practices and to evaluate the adequacy of energy and nutrient intakes of young children in subsistence farming rural households in North Wollo, Ethiopia.

Design

A cross-sectional study examining sociodemographic status, anthropometry, breast-feeding and complementary feeding practices using two in-home non-consecutive 24 h recalls.

Settings

Two rural villages in the highlands and lowlands of Gobalafto district, North Wollo.

Subjects

Seventy-six young children aged 12–23 months, thirty-nine from the lowlands and thirty-seven from the highlands.

Results

About 33 % of the children, ∼46 % in the highlands and 24 % in the lowlands (P = 0·05), were stunted. Complementary diets were low in animal products, fruits and vegetables. Cereals and legumes were the major sources of energy, protein, Ca, Fe, Zn and vitamin A. Legumes with potentially toxic components (grass pea, broad beans) and low nutrient-dense beverages such as tea were frequently consumed. Intakes of energy, Ca, Zn, vitamin A and vitamin C from complementary foods were below WHO recommendations assuming average breast-milk intakes. In contrast, Fe and protein intakes and densities met WHO recommendations. Although vitamin C intakes and densities were higher (P < 0·05) for the lowlands, they remained far below WHO recommendations.

Conclusions

Interventions promoting the WHO guiding principles for complementary feeding practices and behaviours that take the agro-ecological contexts into account are needed here. Furthermore, specific recommendations should be formulated to discourage the consumption of grass pea, broad beans and low nutrient-dense beverages such as tea.
Predicting Illness-Related Outcomes with FCB-TI Trait Pairs
Authors: Fruehstorfer David B. , Veronie Linda , Cremeans-Smith Julie K. , Newberry Benjamin H.
Published: December 2012

The Formal Characteristics of Behavior–Temperament Inventory (FCB-TI; Strelau & Zawadzki, 1993 , 1995a ) evolved from the Pavlovian CNS typology, which emphasizes the “formal” (energetic and temporal) aspects of behavior. Research suggests that the scales of the FCB-TI – Briskness (BR), Endurance (EN), Sensory Sensitivity (SS), Perseveration (PE), Activity (AC), and Emotional Reactivity (ER) – should predict illness-related variables. We examined the ability of PE to account for somatic anxiety and self-reported illness/injury item endorsement in 1,824 individuals. The analyses went beyond an examination of the predictive powers of PE alone by focusing on the nonadditive effects of PE in two-trait interactions (e.g., PE × SS, PE × ER). Regression analyses indicated that PE accounted for significant variance in somatic anxiety, while interactions of PE with other FCB-TI traits accounted for significant variance in total illness reports as well as common illness and inflammations. The interaction of PE × SS was most often related to illness endorsements.
“The Princess and the Pea”
Authors: Kantor-Martynuska Joanna
Published: December 2012

The paper concerns sensory sensitivity (SS), a formal characteristic of behavior Strelau introduced in his regulative theory of temperament (RTT). SS is the ability to react to sensory stimuli of low stimulatory value. It contributes to the regulation of stimulation by setting thresholds for the stimulatory input an individual is able to react to. Strelau’s recognition of the orthogonal character of SS and emotional reactivity is the strength of the theoretical concept of SS. However, this approach fails to give the multimodality of sensory perception and the relationship of SS to attention sufficient consideration. References to other theories of sensitivity and the relevant empirical findings shed light on the theoretical and functional value of Strelau’s concept of SS. Both the theory and the corresponding SS scale in the Formal Characteristics of Behavior – Temperament Inventory (FCB-TI) reveal certain weaknesses. This paper presents a critical approach to both the theoretical approach to SS in the RTT and its operationalization. It gives suggestions for the revision of the theoretical construct of SS and of its psychometric measure. Recognizing the multiple sense-specific sensitivities would transform the concept of SS into a configuration of modality-specific sensitivities and produce an individual sensitivity profile.
The Type of Temperament, Mood, and Strategies of Categorization
Authors: Wytykowska Agata
Published: December 2012

In Strelau’s theory of temperament (RTT), there are four types of temperament, differentiated according to low vs. high stimulation processing capacity and to the level of their internal harmonization. The type of temperament is considered harmonized when the constellation of all temperamental traits is internally matched to the need for stimulation, which is related to effectiveness of stimulation processing. In nonharmonized temperamental structure, an internal mismatch is observed which is linked to ineffectiveness of stimulation processing. The three studies presented here investigated the relationship between temperamental structures and the strategies of categorization. Results revealed that subjects with harmonized structures efficiently control the level of stimulation stemming from the cognitive activity, independent of the affective value of situation. The pattern of results attained for subjects with nonharmonized structures was more ambiguous: They were as good as subjects with harmonized structures at adjusting the way of information processing to their stimulation processing capacities, but they also proved to be more responsive to the affective character of stimulation (positive or negative mood).
Temperamental Traits and Severity of PTSD Symptoms
Authors: Zawadzki Bogdan , Popiel Agnieszka
Published: December 2012

The paper presents the results of a longitudinal study of two groups of participants of motor vehicle accidents (MVA). They were investigated twice: The first time after 1–6 months (N = 362) or 12–24 months (N = 337) after a MVA, and then 1 year after the initial assessment. We assumed that, among the environmental variables (severity of experienced trauma, trauma-related prolonged stressors, other traumatic event and social support), two temperamental traits, emotional reactivity and briskness, would be factors influencing the severity of posttraumatic stress disorder. We also assumed that, after a longer distance from the MVA, temperament would be affected by symptoms of PTSD. Analysis of the cross-lagged effects confirmed the expectations regarding the “temperamental vulnerability” to PTSD in the shorter timespan after the MVA, indicating the process of “complication” and leading to changes in temperament under the influence of the disorder. Moreover, emotional reactivity was associated concurrently with higher levels of PTSD symptoms, especially in interaction with the severity of experienced trauma. Emotional reactivity and briskness also predicted changes in symptom severity, after controlling for the initial PTSD level and especially in interaction with trauma-related prolonged stressors. We propose implications of the results in our understanding “enduring personality change after catastrophic experience” as a diagnostic category in the ICD-10 and underline the significance of temperament as a factor influencing individual “vulnerability” to trauma.
Permanent fore‐arc extension and seismic segmentation: Insights from the 2010 Maule earthquake, Chile
Authors: Aron Felipe , Allmendinger Richard W. , Cembrano José , González Gabriel , Yáñez Gonzalo
Published: December 2012

Geologists have long known that young normal faults are an important structural element of the Andean Coastal Cordillera, but their relationship to the subduction seismic cycle is still unclear. Some of the largest aftershocks of the 2010 Mw 8.8 Maule earthquake in central Chile were nucleated on upper plate normal faults, including the Mw 6.9 and 7.0 events of the Pichilemu earthquake sequence. We use the available coseismic GPS displacements, moment tensor sums, and slip distribution models for the Maule earthquake to compute the static strain and stress fields imposed on the upper plate by slip on the subduction interface. The extensional strains calculated from coseismic GPS and from a moment tensor sum of the Pichilemu events have similar orientations and orders of magnitude. The normal Coulomb stress increment (CSI) on the Pichilemu fault has maximum positive stresses as high as 4.9 MPa. Regionally, the Maule event produced a semi‐elliptical, radial pattern of static extension and deviatoric tension (CSI > 1.5 MPa) along the Coastal Cordillera enclosing the rupture area. This elliptical pattern mimics the trends of the major upper‐crustal structures. The static deformation field produced by a great subduction earthquake is an effective mechanism for generating permanent extension above the seismogenic zone, reactivating suitably oriented, long‐lived normal faults. We suggest that the semi‐elliptical outline of the first‐order structures along the Coastal Cordillera may define the location of a characteristic, long‐lived megathrust segment. This observation implies a persistence at least over the Quaternary of great subduction ruptures along the Maule segment.
Speciation and trends of organic nitrogen in southeastern U.S. fine particulate matter (PM2.5)
Authors: Samy Shar , Robinson James , Rumsey Ian C. , Walker John T. , Hays Michael D.
Published: December 2012

The impacts of meteorology and air quality on the concentrations and relative distributions of free and combined amino acids (FAA; CAA) are evaluated during a month‐long sampling campaign at a semiurban site in the southeastern U.S. The average FAA concentration in fine aerosols (PM2.5) was 11 ± 6 ng m–3, while CAA was found to be several times higher at 46 ± 21 ng m–3. Glycine and alanine were the most abundant amino acids, accounting for 48% of FAA and 58% of the CAA, while distinct differences were observed in compound distributions; glutamic acid, aspartic acid, serine, and threonine accounted for a further 29% of FAA and 30% of the total CAA. An intense rainfall event during the campaign demonstrated the significant impact of meteorological and air quality conditions on FAA‐CAA concentrations and distributions. Correlative trends with atmospheric oxidant (ozone) and inorganic nitrogen levels suggest an important role for atmospheric processing. The liquid chromatography‐mass spectrometry (quadrupole time‐of‐flight) technique used in this study allowed for detection of coextracted water‐soluble organic compounds and characterization of a larger fraction of the organic nitrogen mass. N‐heterocyclic compounds were detected in samples from this campaign, indicating a likely biomass burning source contribution for organic nitrogen.
Relative contributions of secondary organic aerosol formation from toluene, xylenes, isoprene, and monoterpenes in Hong Kong and Guangzhou in the Pearl River Delta, China: an emission‐based box modeling study
Authors: Wang Siyuan , Wu Dongwei , Wang Xin‐Ming , Fung Jimmy Chi‐Hung , Yu Jian Zhen
Published: December 2012

Secondary organic aerosols (SOA) formed from common anthropogenic and biogenic volatile organic compounds (VOCs) account for a significant portion of organic particulate matter in the ambient atmosphere. The Pearl River Delta (PRD) in southern China, located in the subtropics and as a region with intensive manufacturing industries, has significant emissions of both anthropogenic and biogenic VOCs. Two recent SOA tracer‐based measurement studies, one in Hong Kong (located at the mouth of the PRD) and the other at a site 20 to 50 km downwind of urban Guangzhou districts in the middle of the PRD, show a rather considerable difference in the relative SOA contributions from one group of two biogenic VOCs (isoprene and monoterpenes) and one group of anthropogenic VOCs, namely, toluene + xylenes. In Hong Kong, more SOA was formed from isoprene and monoterpenes than from toluene and xylenes, although the relative contributions of the two groups of VOCs were reversed at the site downwind of Guangzhou. An emission‐based 0‐D box model has been developed to investigate this issue. The emission inputs of major inorganic pollutants and VOCs are generated using the programs Sparse Matrix Operator Kernel Emissions and Model of Emissions of Gases and Aerosols from Nature for this region. Toluene/xylene emissions in Guangzhou are more than twice that in Hong Kong whereas isoprene and monoterpenes emissions were similar at the two locations. The model incorporates a CB05 chemical mechanism and gas–particle partitioning of condensable VOC oxidation products to simulate SOA formation from major VOCs including isoprene, monoterpenes, toluene, and xylenes. The model‐simulated VOCs fall within the range of ambient observations, demonstrating reasonable representation of emissions and oxidation of VOCs. The model simulates the sum of the SOA formation from isoprene, monoterpenes, and toluene + xylenes. In Hong Kong, monoterpenes are the major contributor (up to 70%), followed by isoprene (14%–48%) and toluene + xylenes (15%–43%). In Guangzhou, toluene + xylenes contribute more to SOA than isoprene and monoterpenes (up to 76% from toluene + xylenes vs. 13%–44% from isoprene and 10%–45% from monoterpenes). The reasonable agreement between the simulated SOA for the target VOCs and the tracer‐based measurements suggests that the significantly larger toluene + xylene emissions in Guangzhou could explain the substantial difference in relative SOA contributions by the two groups of VOCs in the two cities. This work has also identified a lack of good measurements of monoterpenes and their SOA tracers to be an important data deficiency in assessing the relative contributions of biogenic and anthropogenic VOCs to SOA in this region.
Numerical modeling of lava‐regolith heat transfer on the Moon and implications for the preservation of implanted volatiles
Authors: Rumpf M. Elise , Fagents Sarah A. , Crawford Ian A. , Joy Katherine H.
Published: December 2012

We have performed a series of numerical simulations of heat transfer between lunar lava flows and the underlying regolith with the goal of determining the depths in the substrate beneath which implanted extralunar volatiles would survive outgassing by the downward‐propagating heat pulse. Exogenous materials of interest include solar wind and solar flare particles, and the cosmogenic products of galactic cosmic ray (GCR) particles emplaced in the lunar regolith early in Solar System history. Extraction and analysis during future lunar missions would yield information about the evolution of the Sun and inner Solar System environment. Particles implanted in regolith deposits may be protected from gardening and saturation if buried by a lava flow, but must be sufficiently deep in the regolith to survive the consequent heating. Our simulations include detailed treatments of lava and regolith thermophysical properties (thermal conductivity, specific heat capacity), which vary widely over the temperature range relevant to lava flows in the lunar environment (~200 to >1500 K). Simulations adopting temperature‐dependent properties, together with a treatment of latent heat of lava crystallization, indicate that implanted volatiles would be fully preserved at depths greater than 20 cm beneath 1 m thick lava flows, ~60% deeper than predicted by simulations employing constant properties. These results highlight the necessity of appropriate prescription of material properties. Consideration of the range of lunar lava flow thicknesses allows us to determine the range of depths from which pristine samples may be recovered.
Incorporation of a gravity wave momentum deposition parameterization into the Venus Thermosphere General Circulation Model (VTGCM)
Authors: Zalucha A. M. , Brecht A. S. , Rafkin S. , Bougher S. W. , Alexander M. J.
Published: December 2012

The gravity wave‐drag parameterization of Alexander and Dunkerton (1999) was implemented into a Venus Thermosphere General Circulation Model (VTGCM) to investigate breaking gravity waves as a source of momentum deposition in Venus' thermosphere. Previously, deceleration of zonal jets on the morning and evening terminators in models was accomplished via Rayleigh friction, a linear drag law that is not directly linked to any physical mechanism. The Alexander and Dunkerton (1999) parameterization deposits all of the momentum of a breaking wave at the breaking altitude and features a spectrum of wave phase speeds whose amplitudes are distributed as a Gaussian about a center phase speed. We did not find a combination of wave parameters (namely, center phase speed, amplitude at center phase speed, and distribution width) to produce sufficient drag in the jet cores that would bring VTGCM density and nightglow emissions into agreement with Venus Express observations. The zonal wind shear from 100 to 120 km altitude is very strong. Gravity waves launched below 100 km either break in the strong shear zones below 115 km or are reflected and do not propagate into the jet core regions where drag is needed. The results we present demonstrate that parameterizations developed for the middle atmosphere do not work in the thermosphere and that appropriate damping mechanisms other than nonlinear breaking/saturation dominate and should be accounted for at these heights.
The petrological expression of early Mars volcanism
Authors: Baratoux D. , Toplis M. J. , Monnereau M. , Sautter V.
Published: December 2012

Crystallization products of liquids produced by partial melting of a possible Martian mantle for conditions covering the earliest Noachian era to the most recent Amazonian times have been modeled using the MELTS thermodynamic calculator. The results imply a transition from low‐calcium pyroxene dominated assemblages in the Noachian to high‐calcium pyroxene assemblages in the Hesperian and Amazonian, which is remarkably consistent with observations made by orbiting visible and near‐infrared spectrometers. This transition is interpreted as the consequence of the thermal evolution of the mantle, with no need for exotic conditions, such as higher water content or nonchondritic Ca/Al ratio of the mantle source, to produce low‐calcium pyroxene rich lithologies. Our results are compatible with numerical models of the thermal evolution of Mars that predict high production rates of crust on early Mars, implying that Noachian rocks exposed at the surface may be petrological expressions of this volcanism rather than being associated with mantle overturn following the crystallization of a magma ocean.
Global biogeography of highly diverse protistan communities in soil
Authors: Bates Scott T , Clemente Jose C , Flores Gilberto E , Walters William Anthony , Parfrey Laura Wegener , Knight Rob , Fierer Noah
Published: December 2012

Protists are ubiquitous members of soil microbial communities, but the structure of these communities, and the factors that influence their diversity, are poorly understood. We used barcoded pyrosequencing to survey comprehensively the diversity of soil protists from 40 sites across a broad geographic range that represent a variety of biome types, from tropical forests to deserts. In addition to taxa known to be dominant in soil, including Cercozoa and Ciliophora, we found high relative abundances of groups such as Apicomplexa and Dinophyceae that have not previously been recognized as being important components of soil microbial communities. Soil protistan communities were highly diverse, approaching the extreme diversity of their bacterial counterparts across the same sites. Like bacterial taxa, protistan taxa were not globally distributed, and the composition of these communities diverged considerably across large geographic distances. However, soil protistan and bacterial communities exhibit very different global-scale biogeographical patterns, with protistan communities strongly structured by climatic conditions that regulate annual soil moisture availability.
Phylogenetic conservatism of functional traits in microorganisms
Authors: Martiny Adam C , Treseder Kathleen , Pusch Gordon
Published: December 2012

A central question in biology is how biodiversity influences ecosystem functioning. Underlying this is the relationship between organismal phylogeny and the presence of specific functional traits. The relationship is complicated by gene loss and convergent evolution, resulting in the polyphyletic distribution of many traits. In microorganisms, lateral gene transfer can further distort the linkage between phylogeny and the presence of specific functional traits. To identify the phylogenetic conservation of specific traits in microorganisms, we developed a new phylogenetic metric—consenTRAIT—to estimate the clade depth where organisms share a trait. We then analyzed the distribution of 89 functional traits across a broad range of Bacteria and Archaea using genotypic and phenotypic data. A total of 93% of the traits were significantly non-randomly distributed, which suggested that vertical inheritance was generally important for the phylogenetic dispersion of functional traits in microorganisms. Further, traits in microbes were associated with a continuum of trait depths (τD), ranging from a few deep to many shallow clades (average τD: 0.101–0.0011 rRNA sequence dissimilarity). Next, we demonstrated that the dispersion and the depth of clades that contain a trait is correlated with the trait’s complexity. Specifically, complex traits encoded by many genes like photosynthesis and methanogenesis were found in a few deep clusters, whereas the ability to use simple carbon substrates was highly phylogenetically dispersed. On the basis of these results, we propose a framework for predicting the phylogenetic conservatism of functional traits depending on the complexity of the trait. This framework enables predicting how variation in microbial composition may affect microbially-mediated ecosystem processes as well as linking phylogenetic and trait-based patterns of biogeography.
In situ substrate preferences of abundant bacterioplankton populations in a prealpine freshwater lake
Authors: Salcher Michaela M , Posch Thomas , Pernthaler Jakob
Published: December 2012

The substrate partitioning of sympatric populations of freshwater bacterioplankton was studied via microautoradiography and fluorescence in situ hybridization. Fourteen radiolabeled tracers were used to assess microbial acquisition spectra of low-molecular-weight (LMW) organic compounds. The most abundant group, ac1 Actinobacteria, were highly active in leucine, thymidine and glucose assimilation, whereas Alphaproteobacteria from the LD12 lineage (the freshwater sister clade of SAR11) only weakly incorporated these tracers, but exhibited a distinct preference for glutamine and glutamate. Different Bacteroidetes showed contrasting uptake patterns: Flavobacteriales did not incorporate significant amounts of any LMW compound, and Cyclobacteriaceae were clearly specialized on leucine, glucose and arginine. Betaproteobacteria represented the most active and versatile bacterioplankton fraction and >90% of them could be assigned to eight species- to genus-like populations with contrasting substrate specialization. Limnohabitans sp. were the most abundant and active Betaproteobacteria, incorporating almost all tracers. While three closely related betaproteobacterial populations substantially differed in their uptake spectra, two more distantly related lineages had very similar preferences, and one population did not incorporate any tracer. The dominant phototrophic microorganism, the filamentous cyanobacterium Planktothrix rubescens, assimilated several substrates, whereas other (pico)cyanobacteria had no heterotrophic activity. The variable extent of specialization by the studied bacterial taxa on subsets of LMW compounds contrasts theoretical considerations about non-selective microbial substrate assimilation at oligotrophic conditions. This physiological niche separation might be one explanation for the coexistence of freshwater bacterioplankton species in a seemingly uniform environment.
Autoimmune disorder phenotypes in Hvcn1-deficient mice
Authors: Sasaki Mari , Tojo Akihiro , Okochi Yoshifumi , Miyawaki Nana , Kamimura Daisuke , Yamaguchi Akihito , Murakami Masaaki , Okamura Yasushi
Published: December 2012

Hv channels (voltage-gated proton channels) are expressed in blood cells, microglia and some types of epithelial cells. In neutrophils Hv channels regulate the production of reactive oxygen species through regulation of membrane potential and intracellular pH. Hv channels have also been suggested to play a role in sperm physiology in the human. However, the functions of the Hv channel at the whole-body level are not fully understood. In the present paper we show that Hvcn1 (voltage-gated hydrogen channel 1)-knockout mice show splenomegaly, autoantibodies and nephritis, that are reminiscent of human autoimmune diseases phenotypes. The number of activated T-cells was larger in Hvcn1-deficient mice than in the wild-type mice. Upon viral infection this was remarkably enhanced in Hvcn1-deficient mice. The production of superoxide anion in T-cells upon stimulation with PMA was significantly attenuated in the Hvcn1-deficient mice. These results suggest that Hv channels regulate T-cell homoeostasis in vivo.
Designing the rectification behavior of molecular diodes
Authors: Mahmoud Ahmed , Lugli Paolo
Published: December 2012

Thanks to major advances in chemical and fabrication processes, various electronic devices based on single molecules have been demonstrated. On the theoretical level, many attempts have been made to provide a clear view of the charge transport mechanism through molecules. However, the overall picture is not yet complete. In this study, we show that the rectification of a molecular device can be controlled by enforcing the potential drop profile along the molecule. The insertion of a resistive molecular path near the metallic electrode(s) can drastically alter the rectification behavior. Our observation paves the way for a better control of molecular devices.