bluuebunny/crossref_metadata_2025 huggingface dataset:
Fish Oil Supplementation Reduces Cachexia and Tumor Growth While Improving Renal Function in Tumor‐Bearing Rats
Authors: Coelho Isabela , Casare Fernando , Pequito Danielle C. T. , Borghetti Gina , Yamazaki Ricardo K. , Brito Gleisson A. P. , Kryczyk Marcelo , Fernandes Luiz Claudio , Coimbra Terezila M. , Fernandez Ricardo
Published: September 2012

The objective of the present work was to study the renal function of healthy and tumor‐bearing rats chronically supplemented with fish oil (FO), a source of n‐3 polyunsaturated fatty acids. Weanling male rats were divided in two groups, one control (C) and another orally supplemented for 70 days with FO (1 g/kg body weight). After this time, half the animals of each group were injected in the right flank with a suspension of Walker 256 tumor cells (W and WFO). The W group had less proteinemia reflecting cachectic proteolysis, FO reversed this fact. Tumor weight gain was also reduced in WFO. Glomerular filtration rate (GFR) was not different in FO or W compared to C, but was higher in WFO. Renal plasma flow (RPF) was higher in the FO supplemented groups. The W group had lower plasma osmolality than the C group, but FO supplementation resulted in normalization of this parameter. Fractional sodium excretion (FENa+) of FO rats was similar to C. Proximal Na+ reabsorption, evaluated by lithium clearance, was similar among the groups. Urinary thromboxane B2 (TXB2) excretion was lower in the supplemented groups. The number of macrophages in renal tissue was higher in W compared to C rats, but was lower in WFO rats compared to W rats. In conclusion, FO supplementation resulted in less tumor growth and cachexia, and appeared to be renoprotective, as suggested by higher RPF and GFR.
Controlling Product Composition of Metathesized Triolein by Reaction Concentrations
Authors: Li Shaojun , Hojabri Leila , Narine Suresh S.
Published: September 2012

Triolein was used as a model material to investigate the effect of concentration on self metathesis of vegetable oils. The metathesis reaction using Grubbs' second generation catalyst (used at a level of 2.5 mol % of triolein) was carried out at 38 °C using dichloromethane as the solvent. The products from three reaction concentrations were investigated: neat, 10 and 20 mmol/L. The products from the reactions were separated by column chromatography and the fractions were characterized by 1H‐NMR, 13C‐NMR, MS and FTIR. Mono‐cyclic and multi‐cyclic triacylglycerol‐based compounds and different level aliphatic triacylglycerol‐like oligomers were produced, but the compositions of the products were found to be significantly controlled by the reaction concentrations. Cyclic compounds were favorably produced at lower reaction concentrations, whereas, linear oligomers were favorably produced at higher reaction concentrations. Cyclic compounds were formed mainly from adjacent fatty acid chains on the glycerol backbone. In the neat reactions, only linear oligomers were produced. The trans/cis ratios increased as concentration was increased.
The Soft Underbelly of Evolution?
Authors: Branch Glenn , Scott Eugenie C.
Published: September 2012

Evolution and the origin of life are separate, if connected, topics, but they are frequently conflated—especially by creationists. Regarding the natural origin of life as “the soft underbelly” of evolution, creationists argue that it is impossible, improbable, or insusceptible to scientific investigation. Underlying their arguments is the hope that the failure of scientific research on the origin of life is evidence for a supernatural account. It is crucial for teachers to understand the nature of science in order to be able to explain why appeals to the supernatural are out of place in explaining the origin of life and why scientific research on the origin of life is not intrinsically a threat to faith.
Learning to diagnose using patient video case in paediatrics: perceptive and
cognitive processes
Authors: Balslev Thomas
Published: September 2012

Thomas Balslev, a paediatric neurologist and educational researcher, defended his
thesis on 24 November 2011. The thesis included five published papers, and investigated
learning with authentic, brief patient video cases. With analysis of a video case in a
small group, learning processes and sharing of knowledge was intensely stimulated. Small
group discussion and subsequent listening to an expert’s think-aloud were particularly
effective approaches to enhance diagnostic accuracy among non-experts. In a descriptive
study, expertise-related differences during analysis of patient video cases were
characterized, and in a controlled study, different types of visual modelling were
tested.
An Integrative Review of Factors Related to Patient Satisfaction With General Anesthesia Care
Authors: Hawkins Robert J. , Swanson Barbara , Kremer Michael J.
Published: September 2012

Surgery is typically performed using one or more types of anesthesia. An important patient outcome related to the anesthetic, and a measure of quality from the patient's perspective, is patient satisfaction with anesthesia care. Currently, no psychometrically validated instruments that measure patient satisfaction with general anesthesia care are available in the United States. This integrative review focuses on identifying factors related to adult patients' satisfaction with general anesthesia care. We found the most frequently mentioned modifiable factors related to patient satisfaction were information provided and pain or discomfort. The only nonmodifiable factor with sufficient evidence to include in future studies on instrument development is the patient's age. This review provides information that can help in the design and implementation of quality improvement initiatives and in the development of an instrument to measure patient satisfaction with general anesthesia care.
Lateral gene transfer between the Bacteroidetes and Acidobacteria: The case of α‐l‐rhamnosidases
Authors: Naumoff Daniil G. , Dedysh Svetlana N.
Published: September 2012

α‐l‐Rhamnosidases catalyze the hydrolysis of the terminal α‐l‐rhamnose residues in various carbohydrates. The catalytic domains in most of these enzymes belong to the families GH78 and GH106 of glycoside hydrolases. In this study, we show that almost all genes encoding the GH78‐ and GH106‐containing proteins from members of the poorly characterized bacterial phylum Acidobacteria originated from precursors belonging to the phylum Bacteroidetes. Members of the Acidobacteria and Bacteroidetes display similar functional capabilities and specialize on degradation of plant‐derived organic matter. Several proposed lateral gene transfers between the Acidobacteria and Bacteroidetes occurred presumably during specialization of these bacteria for their environments.
Do antioxidants impair signaling by reactive oxygen species and lipid oxidation products?
Authors: Niki Etsuo
Published: September 2012

Oxidative modification of biologically essential molecules by reactive oxygen and nitrogen species (ROS/RNS) has been implicated in the pathogenesis of various diseases. At the same time, roles of ROS/RNS as physiological signaling messenger have been established. Lipid oxidation products also have two faces. It is argued that the radical scavenging antioxidants taken from diet or supplement may impair such beneficial effects of ROS/RNS and lipid oxidation products. However, it is unlikely that antioxidants impair physiologically important signaling, since the antioxidants do not scavenge signaling ROS/RNS nor do they inhibit the formation of signaling molecules. Lipid peroxidation products are not produced on purpose and inhibition of lipid peroxidation by antioxidants should be beneficial for maintenance of health and reducing disease risk.
Histaminylation of glutamine residues is a novel posttranslational modification implicated in G‐protein signaling
Authors: Vowinckel Jakob , Stahlberg Silke , Paulmann Nils , Bluemlein Katharina , Grohmann Maik , Ralser Markus , Walther Diego J.
Published: September 2012

CDC42
physically interacts with
Pak3
by pull down (View interaction)
The cytoplasmic tail of heparin‐binding EGF‐like growth factor regulates bidirectional intracellular trafficking between the plasma membrane and ER
Authors: Hieda Miki , Koizumi Michiko , Higashi Chiduru , Tachibana Taro , Taguchi Tomohiko , Higashiyama Shigeki
Published: September 2012

Heparin‐binding epidermal growth factor (EGF)‐ like growth factor (HB‐EGF) is synthesized in the ER, transported along the exocytic pathway, and expressed on the plasma membrane as a type I transmembrane protein. Upon extracellular stimulation, HB‐EGF, either proHB‐EGF or the shed form HB‐EGF‐CTF, undergoes endocytosis and is then transported retrogradely to the ER. In this study, we showed the essential contribution of the short cytoplasmic tail of HB‐EGF (HB‐EGF‐cyto) to the bidirectional intracellular trafficking between the ER and plasma membrane and revealed several critical amino acids residues that are responsible for internalization from the plasma membrane and ER targeting. We suggest that these anterograde and retrograde sorting signals within HB‐EGF‐cyto are strictly regulated by protein modification and conformation.
In silico prediction of a disease‐associated STIL mutant and its affect on the recruitment of centromere protein J (CENPJ)
Authors: Kumar Ambuj , Rajendran Vidya , Sethumadhavan Rao , Purohit Rituraj
Published: September 2012

Human STIL (SCL/TAL1 interrupting locus) protein maintains centriole stability and spindle pole localisation. It helps in recruitment of CENPJ (Centromere protein J)/CPAP (centrosomal P4.1‐associated protein) and other centrosomal proteins. Mutations in STIL protein are reported in several disorders, especially in deregulation of cell cycle cascades. In this work, we examined the non‐synonymous single nucleotide polymorphisms (nsSNPs) reported in STIL protein for their disease association. Different SNP prediction tools were used to predict disease‐associated nsSNPs. Our evaluation technique predicted rs147744459 (R242C) as a highly deleterious disease‐associated nsSNP and its interaction behaviour with CENPJ protein. Molecular modelling, docking and molecular dynamics simulation were conducted to examine the structural consequences of the predicted disease‐associated mutation. By molecular dynamic simulation we observed structural consequences of R242C mutation which affects interaction of STIL and CENPJ functional domains. The result obtained in this study will provide a biophysical insight into future investigations of pathological nsSNPs using a computational platform.
Cerebral white matter disease is associated with Alzheimer pathology in a prospective cohort
Authors: Moghekar Abhay , Kraut Michael , Elkins Wendy , Troncoso Juan , Zonderman Alan B. , Resnick Susan M. , O'Brien Richard J.
Published: September 2012

Background

Although magnetic resonance imaging (MRI)‐detected white matter disease has been correlated with cognitive decline in the elderly individuals, it is unclear whether white matter disease is primarily responsible for the cognitive deterioration or whether another process is common to both white matter disease and dementia.

Methods

We examined the relationship between Alzheimer‐type brain pathology at autopsy and MRI‐detected cerebral white matter disease in 50 participants from the Baltimore Longitudinal Study of Aging Autopsy Program, a prospective study of aging that includes detailed cognitive assessments.

Results

White matter disease was quantitated in pre‐ and postmortem MRI scans using the Cardiovascular Health Study (CHS) criteria in a blinded manner. We found that several measures of Alzheimer's disease (AD) pathology, including the Consortium to Establish a Registry for Alzheimer's Disease score, Braak score, and a composite AD pathology score, along with hypertension, were significantly associated with CHS white matter score using univariate and multivariate ordinal regression. In contrast, amyloid angiopathy was not independently associated with CHS score. Although a clinical diagnosis of dementia was associated with CHS score in univariate analysis, the association disappeared after accounting for AD pathology.

Conclusion

AD pathology at autopsy is associated with MRI‐detected cerebral white matter disease. This relationship may explain, in part, the association between cerebral white matter disease and cognitive decline in the elderly individuals.
The first data on the Early Proterozoic sialic basement in the eastern West Siberian Platform (studies of the Tyn’yar rhyolite–granite pluton)
Authors: Ivanov K.S. , Erokhin Yu.V. , Ronkin Yu.L. , Khiller V.V. , Rodionov N.V. , Lepikhina O.P.
Published: September 2012

Despite the long history of research, the presence of Precambrian complexes in the West Siberian basement has not been proven. The Tyn’yarskaya 100 and Tyn’yarskaya 101 wells were drilled in the Vakh–Elogui interfluve, in the eastern West Siberian Plate (eastern Khanty-Mansi Autonomous District). At a depth of 1790 m, they stripped a rhyolite extrusion, which graded into A-type alkali granitoids with rare-metal and REE mineralization (thorite, thorogummite, pitchblende, REE-carbonates, chevkinite, and others) downsection. This volcanoplutonic complex is Early Permian (K–Ar age, ∼270 Ma; Rb–Sr age, 275.7 Ma; Sm–Nd age, 276 Ma; U–Pb age, 277 Ma). Some zircon grains from granites are much older (2049 ± 23 Ma, SHRIMP II), suggesting a relationship between the Early Permian granitic magma and the ancient matter. This might have been a granite-metamorphic basement, the partial melting of which produced the Tyn’yar rhyolite–granite body. The Sm–Nd model ages also suggest the participation of a Precambrian substratum in the formation of the rocks under study. Thus, it is quite possible that the Tyn’yar area is underlain by a Proterozoic (∼ 2 Ga) sialic basement, which is an edge of the Siberian Platform thinned by Late Proterozoic–Early Paleozoic rifting and extension.
Sex and Culture Similarities and Differences in Long-Term Partner Preferences
Authors: Neto Félix , da Conceição Pinto Maria , Furnham Adrian
Published: September 2012

A number of studies have described different preference patterns typically found for women and men when selecting a long-term partner. Despite the number of investigations on the topic, one must be careful not to generalise because most studies use samples of North American undergraduates. In this study, heterosexual participants from Brazil and Portugal rated the desirability characteristics in a possible long-term partner. The sample was composed of 402 participants, of whom 187 were Brazilian (92 women and 95 men) from Brasília University, Brazil; and 215 were Portuguese (121 women and 94 men) from Porto University, Portugal. Participants of each culture responded to the same 18 items, measuring four factors: personality, physical attractiveness, resources, and abilities. As predicted, women rated indicators of personality, resources, and abilities significantly higher than men, who rated physical attractiveness higher. Brazilian students rated resources higher than did Portuguese students. The findings are discussed in the context of some evolutionary and sociocultural notions posited in explanations of mating behaviour. Limitations of this methodology are discussed.
Aepyornisas moa: giant birds and global connections in nineteenth-century science
Authors: ANDERSON THOMAS J.
Published: September 2012

This essay explores how the scientific community interpreted the discoveries of extinct giant birds during the mid-nineteenth century on the islands of New Zealand and Madagascar. It argues that theAepyornisof Madagascar was understood through the moa of New Zealand because of the rise of global networks and theories. Indeed, their global connections made giant birds a sensation among the scientific community and together forged theories and associations not possible in isolation. In this way, this paper argues for a closer look at how the creation of science emerged from a world framework that involved multiple sites of discovery and interpretation that continually influenced and reshaped scientific theories. It also stresses the importance of local naturalists in participating in this global exchange of knowledge.
PROFESSOR D. HOWELL PEREGRINE 30 December 1938 – 20 March 2007
Authors: MOFFATT H. K.
Published: September 2012

Howell Peregrine, who died on 20th March after a brief illness, had an exceptionally
long and distinguished period of service for this Journal, first as Assistant Editor
(1979–1980) then Associate Editor (1981–2007). In this capacity, he had editorial
responsibility for some 50 papers every year, more than 1200 in total. This was
a massive contribution to the continuing success of the Journal, to which it is
appropriate and fitting that we pay grateful tribute.
Laser wakefield bubble regime acceleration of electrons in a preformed non uniform plasma channel
Authors: Magesh Kumar K.K. , Tripathi V.K.
Published: September 2012

A model of bubble regime electron acceleration by an intense laser pulse in non uniform plasma channel is developed. The plasma electrons at the front of the pulse and slightly off the laser axis in the plasma channel, experience axial and radial ponderomotive and space charge forces, creating an electron evacuated non uniform ion bubble. The expelled electrons travel along the surface of the bubble and reach the stagnation point, forming an electron sphere of radius re. The electrons of this sphere are pulled into the ion bubble and are accelerated to high energies. The Lorentz boosted frame enabled us to calculate energy gain of a test electron inside the bubble.
ANALYTIC METHODS FOR SELECT SETS
Authors: Gaither J. , Ward M.D.
Published: September 2012

We analyze the asymptotic number of items chosen in a selection procedure. The procedure selects items whose rank among all previous applicants is within the best 100p percent of the number of previously selected items. We use analytic methods to obtain a succinct formula for the first-order asymptotic growth of the expected number of items chosen by the procedure.
IMPROVING THE NORMALIZED IMPORTANCE SAMPLING ESTIMATOR
Authors: Ghamami Samim , Ross Sheldon M.
Published: September 2012

The normalized importance sampling estimator allows the target density f to be known only up to a multiplicative constant. We indicate how it can be derived by a delta method-based approximation of a Rao–Blackwellized acceptance rejection estimator. Using additional terms in the delta method then results on a new estimator that also only requires f to be known only up to a multiplicative constant. Numerical examples indicate that the new estimator usually outperforms the normalized importance sampling estimator in terms of mean square error.
TESTING FOR REVERSIBILITY IN MARKOV CHAIN DATA
Authors: Steuber Tara L. , Kiessler Peter C. , Lund Robert
Published: September 2012

This paper introduces two statistics that assess whether (or not) a sequence sampled from a stationary time-homogeneous Markov chain on a finite state space is reversible. The test statistics are based on observed deviations of transition sample counts between each pair of states in the chain. First, the joint asymptotic normality of these sample counts is established. This result is then used to construct two chi-squared-based tests for reversibility. Simulations assess the power and type one error of the proposed tests.
Bacteriological and molecular detection of Mycobacterium bovis in cattle with inconclusive results to intradermal tuberculin tests
Authors: ZARDEN C. F. O. , MARASSI C. D. , CARVALHO A. C. , FIGUEIREDO E. E. S. , LILENBAUM W.
Published: September 2012

A dairy herd (77 cows) from Rio de Janeiro, Brazil, with a history of tuberculosis infection was tested by a comparative cervical test (CCT). Seventeen cows were reactive and seven were inconclusive (swelling ⩾2·0 mm and ⩽3·9 mm, respectively). All of these 24 cows were slaughtered and necropsied; samples from lungs and lymph nodes were collected for multiplex polymerase chain reaction (PCR) and culturing. Infection was confirmed in 23/24 (95·8%) of the slaughtered animals (five by culturing, four by PCR, and 14 by both tests). All cows with inconclusive results at CCT were confirmed as infected. Although slaughter of inconclusive reactor cows is not mandatory in many countries, our study provided evidence to support the slaughter of these cows, at least during an outbreak.
On cosmopolitan self-determination
Authors: SOMEK ALEXANDER
Published: September 2012

In order to arrive at an adequate understanding of the changing Westphalian world, it is necessary to distinguish political self-determination from its cosmopolitan counterpart. While political self-determination has its place in a familiar and common space, cosmopolitan self-determination stands for unbounded collective self-determination among strangers. Two forms can be distinguished. In its mixed form, it is tied in with political self-determination, adopting the latter as a medium for realizing common autonomy among those who are foreign to one another. Virtual representation is essential to understanding how cosmopolitans are connected to bounded political spaces. In its pure form, by contrast, cosmopolitan self-determination detaches itself from political judgement and finds its major role in authorizing risk management and crisis intervention. It lends expression to the impoverishment suffered by collective freedom in an administered world. Any calibration of the relationship between political and cosmopolitan self-determination must examine the general social conditions enabling an autonomous life.
Gerontopsychology in Austria
Authors: Auer Stefanie R. , Gatterer Gerald
Published: September 2012

In Austria, gerontopsychology is seen as a subdiscipline of clinical psychology which was influenced by many additional disciplines such as developmental psychology, health psychology, geriatrics, and gerontosociology. Gerontopsychology is gaining in importance in the light of recent epidemiological developments. The Gerontopsychology Working Group of the Austrian Psychological Association has taken up the initiative and developed a specialized curriculum. Its content as well as other recent initiatives are described in this contribution.
Mixing, entropy and reactive solute transport
Authors: Chiogna Gabriele , Hochstetler David L. , Bellin Alberto , Kitanidis Peter K. , Rolle Massimo
Published: September 2012

Mixing processes significantly affect reactive solute transport in fluids. For example, contaminant degradation in environmental aquatic systems can be limited either by the availability of one or more reactants, brought into contact by physical mixing, or by the kinetics of the (bio)chemical transformations. Appropriate metrics are needed to accurately quantify the interplay between mixing and reactive processes. The exponential of the Shannon entropy of the concentration probability distribution has been proposed and applied to quantify the dilution of conservative solutes either in a given volume (dilution index) or in a given water flux (flux‐related dilution index). In this work we derive the transport equation for the entropy of a reactive solute. Adopting a flux‐related framework, we show that the degree of uniformity of the solute mass flux distribution for a reactive species and its rate of change are informative measures of physical and (bio)chemical processes and their complex interaction.
A global hybrid model for Mercury's interaction with the solar wind: Case study of the dipole representation
Authors: Richer E. , Modolo R. , Chanteur G. M. , Hess S. , Leblanc F.
Published: September 2012

The interaction of the solar wind (SW) with the magnetic field of Mercury is investigated by means of a three dimensional parallelized multispecies hybrid model. A comparison between two mathematical representations of Mercury's intrinsic magnetic field is studied. The first model is an Offset Dipole (OD) having the offset and dipolar moment reported by Anderson et al. (2011). The second model is a combination of a Dipole and a Quadrupole (DQ), the total field is fitted to the offset dipolar field, for northern latitudes greater than 50°. Simulations reproduce the features which characterize Mercury's interaction with the SW, encompassing the Bow Shock (BS), the magnetosheath, the magnetotail, the “cusps” region and the neutral current sheet. Global hybrid simulations of the Hermean magnetosphere run for the OD and DQ models demonstrate that the southern parts of the magnetospheres produced by the OD and DQ models differ greatly in topology and volume meanwhile their northern parts‐are quite similar. In particular the DQ model exhibits a dome of closed field lines around the south pole in contrast to the OD. Without further information on the intrinsic magnetic field of the planet in the southern region which should be provided by BepiColombo after year 2020, we can only speculate on the influence of the different magnetic topologies on the magnetospheric dynamics.
Mesoscale eddies in the northeastern Pacific tropical‐subtropical transition zone: Statistical characterization from satellite altimetry
Authors: Kurczyn J. A. , Beier E. , Lavín M. F. , Chaigneau A.
Published: September 2012

Mesoscale eddies in the northeastern Pacific tropical‐subtropical transition zone (16°N–30°N; 130°W–102°W) are analyzed using nearly 18 years of satellite altimetry and an automated eddy‐identification algorithm. Eddies that lasted more than 10 weeks are described based on the analysis of 465 anticyclonic and 529 cyclonic eddy trajectories. We found three near‐coastal eddy‐prolific areas: (1) Punta Eugenia, (2) Cabo San Lucas, and (3) Cabo Corrientes. These three areas are located in places where the coastal morphology changes abruptly and strong surface current intensification occurs at some phase of the seasonal cycle. Although mesoscale eddies in these areas have been previously reported, this study provides their first statistically supported characterization. Punta Eugenia showed the highest eddy production (with more cyclones generated), followed by Cabo Corrientes (also with more cyclones) and Cabo San Lucas (with more anticyclones). Cabo Corrientes eddies showed the highest mean values in propagation speed, swirling speed and eddy kinetic energy, whereas Punta Eugenia eddies showed the lowest values. Cyclonic eddies increased their distance traveled and duration from south to north; in contrast anticyclonic eddies increased from north to south. In average, anticyclones tend to travel faster than cyclones in all the subregions. These long‐lived eddies were mainly nonlinear and therefore can redistribute coastal waters relatively far into the open ocean. The peaks in the seasonal signal of eddy generation can be associated with the peaks in the strength of the offshore currents and/or in the Coastal Upwelling Index. No clear relationship could be established between El Niño events and eddy generation.
A spectroscopic analysis of Martian crater central peaks: Formation of the ancient crust
Authors: Skok J. R. , Mustard J. F. , Tornabene L. L. , Pan C. , Rogers D. , Murchie S. L.
Published: September 2012

The earliest formed crust on a single plate planet such as Mars should be preserved, deeply buried under subsequent surface materials. Mars' extensive cratering history would have fractured and disrupted the upper layers of this ancient crust. Large impacts occurring late in Martian geologic history would have excavated and exposed this deeply buried material. We report the compositional analysis of unaltered mafic Martian crater central peaks with high‐resolution spectral data that was used to characterize the presence, distribution and composition of mafic mineralogy. Reflectance spectra of mafic outcrops are modeled with the Modified Gaussian Model (MGM) to determine cation composition of olivine and pyroxene mineral deposits. Observations show that central peaks with unaltered mafic units are only observed in four general regions of Mars. Each mafic unit exhibits spectrally unmixed outcrops of olivine or pyroxene, indicating dunite and pyroxenite dominated compositions instead of basaltic composition common throughout much of the planet. Compositional analysis shows a wide range of olivine Fo# ranging from Fo60 to Fo5. This variation is best explained by a high degree of fractionation in a slowly cooling, differentiating magma body. Pyroxene analysis shows that all the sites in the Southern Highlands are consistent with moderately Fe‐rich, low‐Ca pyroxene. Mineral segregation in the ancient crust could be caused by cumulate crystallization and settling in a large, potentially global, lava lake or near surface plutons driven by a hypothesized early Martian mantle overturn.
Magnetopause and cusp observations at Neptune
Authors: Szabo Adam , Siscoe George L. , Lazarus Alan J. , McNutt Ralph L. , Lepping Ronald P. , Ness Norman F.
Published: September 2012

The fortuitous timing of the Voyager 2 flyby of Neptune provided a unique opportunity to carry out plasma and magnetic field measurements in a subsolar cusp region of a planet. The measured plasma parameters near the inbound magnetopause strongly suggest that a rotational discontinuity separates the magnetosheath and the high‐altitude cusp region. After crossing the magnetopause, a thick layer of magnetosheathlike plasma was observed which can be accounted for by two models: (1) either a cusplike layer of stagnant plasma separated from the magnetosheath by a tangential discontinuity, or (2) or a mantlelike layer of dynamic plasma separated from the sheath by a rotational discontinuity. The plasma observations are more consistent with the mantle interpretation. Distinguishing the mantle and the stagnant cusp models is not possible on geometrical grounds because Voyager 2 crossed the magnetic polar region on the subsolar side. Inside the cusp region, there is an overall decrease in the ion density and a concurrent increase in the magnetic field strength which is consistent with a slow mode expansion fan such as is encountered in Earth's polar regions.
The electron absorption signature of 1989N1
Authors: Selesnick R. S. , Stone E. C.
Published: September 2012

A deep minimum in the energetic (∼ 1 MeV) electron intensity at Neptune is associated with absorption by the satellite 1989NI. The absorption signature is modeled by assuming that the electron losses are replenished by diffusion due to violation of the third adiabatic invariant. It is predominantly a steady state feature, or macrosignature, for which approximate solutions of the diffusion equation lead to an estimate of the radial diffusion coefficient, DLL ≈ 2×10−8 s−1 at L =5. The model suggests a strong L dependence for DLL (≈L7),but an outward displacement of the macrosignature by ≈0.3 unit in Lfrom the location predicted by the model, and differences in the observed and model energy spectra, may indicate that processes such as pitch angle and energy diffusion need to be included for an accurate assessment of the transport coefficients. An approximate solution is also found for the time‐dependent, two‐dimensional diffusion equation including particle drifts and satellite absorption. It shows that the transient microsignatures of the satellite are largely dispersed by drifts and filled in by diffusion. However, the deep intensity minimum appears to include microsignatures near each of the two satellite minimum orbital L shell locations, and these are expected from the diffusion model. At the time of the observations the satellite had recently encountered the inner location, and its microsignature was not yet significantly affected by diffusion. The observed microsignatures are closer together than the minimum orbitalL shell values based on the magnetic field model and, although they are nearly consistent with absorption by 1989N1 alone, the possibility that one was formed by other orbital material cannot presently be ruled out.
Modeling of whistler ray paths in the magnetosphere of Neptune
Authors: Menietti J. D. , Tsintoqdis D. , Gurnett D. A. , Curran D. B.
Published: September 2012

A three‐dimensional ray tracing program is used to investigate the propagation and dispersion of lightning‐generated whistlers in the magnetosphere of Neptune. A simple empirical magnetospheric plasma model based on observational constraints is used for the plasma density distribution, and an offset tilted dipole model is used for the magnetic field. Source positions for the whistlers are chosen along magnetic field lines withL< 3 in agreement with observations. Whistlers with frequencies of about 10 kHz generally propagate veiy near the resonance cone angle for most of the ray path, which produces dispersions considerably larger than those predicted for quasiparallel propagation. Dispersions computed using our “standard” plasma density model are over 30,000 s ✓Hz for “one‐hop” whistlers which is comparable to observed values. In general, the whistlers were found to propagate about 10° in magnetic longitude during one hop and to crossL shells. These results strongly support the existence of whistlers at Neptune. The large dispersions are attributed to the large cold plasma population at Neptune which leads to propagation very near the resonance cone angle for a large part of the ray path.
Emission characteristics and source location of the smooth Neptunian kilometric radiation
Authors: Ladreiter H. P. , Leblanc Y. , Rabl G. K. F. , Rucker H. O.
Published: September 2012

The observations of the planetary radio astronomy (PRA) experiment aboard Voyager 2 reveal the existence of smooth and bursty radio emission. Both recur in a rather regular pattern with a 16.1‐hour period (the Neptunian spin period). We describe the phenomenology of the smooth component in terms of frequency, polarization, and occurrence in magnetic longitude and latitude. The existence of both right‐handed and left‐handed polarized emissions is consistent with two sources (one in each hemisphere) which radiate independently in the TUX mode. Because Voyager passed Neptune at less than 5000 km from the surface at high northern magnetic latitudes, the radio sources were occulted by the planet near the encounter. We have taken advantage of this occultation to locate the northern hemisphere sources by calculating the radio horizon (based on the offset tilted dipole (OTD2) model) for two spacecraft positions close to the encounter. We find that the northern source is located at high magnetic latitudes δm > 40°. By using a geometrical beaming model which assumes emission in a hollow cone pattern we fit the observed PRA intensity profile. The best fit is obtained for a radio source at L=6, thus confirming δm > 40°. The longitudinal extent of the source is at least 180°, from −90° to +90° magnetic longitude. To locate the southern sources we use the large excursions of Voyager 2 to high southern magnetic latitudes. The source is found to be located also at high magnetic latitudes but is possibly more limited in longitude than the northern source. We estimate the uncertainty in source location due to the very limited knowledge of the magnetic field near the Neptunian surface, and we show that the current OTD2 model is satisfactory for the source locations for the lowest observed frequencies; however, an angular uncertainty of about 20° remains for sources in the northern hemisphere. The observed pattern of the smooth emission is strongly frequency dependent, which is in agreement with the azimuthal asymmetries of the magnetic field as predicted by the OTD2 model.
Voyager 2 electron observations in the magnetosphere of Neptune
Authors: Zhang Ming , Richardson John D. , Sittler Edward C.
Published: September 2012

This paper describes electron data obtained during the Neptune encounter by the Voyager 2 plasma science experiment. We derive the densities and temperatures of low‐energy (10–5950 eV) electrons and the electrostatic potential of the spacecraft near Neptune. The data indicate that the escape of charged particles from Triton and the local ionization of atoms in the neutral torus originating from Triton are the major plasma sources. We infer that this neutral torus of hydrogen atoms has a density of about 300 cm‐3 and an inner boundary at 8RN. The data near Neptune exhibit signatures suggesting that both precipitation into Neptune's atmosphere and ring absorption are important plasma loss mechanisms. Plasma transport in the magnetosphere appears to be very fast; the diffusion coefficient is xl0−7L3 RN2 s−1.
Thermal structure and dynamics of Neptune's atmosphere from Voyager measurements
Authors: Conrath B. J. , Flasar F. M. , Gierasch P. J.
Published: September 2012

Spatially resolved Voyager infrared spectra from a global mapping sequence are used to characterize the thermal structure of the atmosphere of Neptune between approximately 50 and 100 mbar. A zonal mean meridional temperature cross section is obtained, which shows a minimum in the upper tropospheric and lower stratospheric temperatures at southern mid latitudes with maxima at the equator and high southern latitudes. This is qualitatively similar to the structure observed on Uranus, even though the obliquities and internal heat fluxes of the two planets are quite different. Thermal wind calculations show zonal wind speeds decreasing with altitude at all latitudes. Within the framework of a linear radiative‐dynamical model, the thermal structure and cloud top winds together imply a frictional damping time comparable in magnitude to the radiative relaxation time; similar results have previously been obtained for the other three giant planets. Periodogram techniques for used to search the observed longitude variations of temperature for possible planetary‐scale wave features. Data from two latitude bins are analyzed; one of the bins includes the Great Dark Spot, and the other is centered on the southern mid‐latitude minimum in the zonal mean temperature. A weakly significant feature near planetary wavenumber 4 is identified at the latitude of the spot. The rest of the variance can be attributed to instrument noise and possibly a broadband meteorological spectrum indistinguishable from white noise.
Hydrocarbons in Neptune's stratosphere from Voyager infrared observations
Authors: Bézard Bruno , Romani Paul N. , Conrath Barney J. , Maguire William C.
Published: September 2012

Emission from the acetylene and ethane bands at 729 and 822 cm‐1detected in the Voyager infrared spectra of Neptune has been analyzed. A large selection of low‐spatial resolution spectra was used to derive the disk‐averaged abundances of C2H2 and C2H6. Under the assumption of uniform vertical distributions above the saturation region, a C2H2 mixing ratio of 6−4+14 x 10 −8 and a C2H6 mixing ratio of 1.5−0.5+2.5 x 10−6 were inferred. The accuracy of the retrievals is limited by the large uncertainty in the stratospheric temperature structure. The maximum contribution to the observed C2H2 and C2H6emission comes from the 0.2‐ and 0.7‐mbar regions, respectively. Mixing ratio profiles derived from photochemical modeling, which are not constant with height above the saturation region, indicate that the hydrocarbon emission is most sensitive to the assumed eddy diffusion coefficient in the millibar region. Either the C2H2 or the C2H6 emission can be reproduced by the photochemical model to within the accuracy of the retrievals, but not both simultaneously. Best fits to both emission features simultaneously occur with C2H2 mixing ratios a factor of 2 too high and C2H6 mixing ratios a factor of 2 too low. We consider this agreement satisfactory considering the unknowns in the chemical and photolytic processes. A set of Voyager spectra at higher spatial resolution was used to study the latitudinal variation of the C2H2 emission between 30°N and 80°S. Zonal mean radiances at the C2H2 peak show a minimum near 50°–60°S and maxima near the south pole and equator. This behavior is similar to that observed at 350 and 250 cm−1, where the lower stratosphere and troposphere are sounded. The mid‐latitude minimum can be explained by a fivefold depletion of acetylene or a temperature decrease of about 15 K (or any combination of the two effects) in the 0.03‐ to 2‐mbar region. The latitude variation in the C2H2emission could result from a circulation pattern forced from deep levels, with upwelling at mid‐latitudes and subsidence at low and high latitudes.
Crustal structure of the Mojave Desert, California: Inferences from Sr and O Isotope studies of Miocene volcanic rocks
Authors: Glazner Allen F. , O'Neil James R.
Published: September 2012

There are strong regional trends in the 87Sr/86Sr ratios and δ18O values of Miocene volcanic rocks from the Mojave Desert of southern California. Because these rocks contain a large component of recycled crust, their isotopic patterns can be used to study pre‐Miocene crustal structure which has been otherwise obscured and distorted by Mesozoic magmatism. Initial whole rock 87Sr/86Sr ratios (ri) increase and δ18O values of silicic magmas decrease with distance inland; ri also increases with SiO2, indicating contamination by radiogenic crustal rocks. Initial 87Sr/86Sr ratios in the most primitive basalts are high (0.7045–0.7095), indicating derivation from an enriched mantle source. Correlations of ri and δ18O with longitude indicate an eastward change in the nature of the contaminant. Silicic rocks have ri and δ18O of 0.705–0.707 and 9–11‰, respectively, in the western and central Mojave Desert, and 0.708–0.710 and 7–8‰ near the Colorado River. High δ18O values of phenocrysts in rhyolites from the western Mojave Desert indicate that these rocks were derived from a high δ18O (>10‰) source. The most likely candidate for this material is underthrust metamorphic rocks of the Mesozoic‐Tertiary subduction complex (e.g., Rand‐Pelona‐Orocopia schist and related lithologies). This implies that some of the North American lithospheric mande was stripped from the western Mojave Desert during Mesozoic‐Paleogene subduction. The smoothness of the eastward increase in ri constrains models for the tectonic evolution of southern California because no discontinuities corresponding to any of several proposed zones of pre‐Tertiary rifting or faulting are present.
Pilot Results of in Vivo Brain Glutathione Measurements in Stroke Patients
Authors: An Li , Dani Krishna A , Shen Jun , Warach Steven
Published: September 2012

Measurement of glutathione concentration for the study of redox status in subjects with neurological disease has been limited to peripheral markers. We recruited 19 subjects with large strokes. Using magnetic resonance spectroscopy we measured brain glutathione concentration in the stroke region and in healthy tissue to calculate a glutathione-ratio. Elevated glutathione-ratio was observed in subacute (<72 hours) subjects without hemorrhagic transformation (mean = 1.19, P = 0.03, n = 6). No trend was seen when all subjects were considered ( n = 19, 3 to 754 hours, range = 0.45 to 1.41). This technique can detect glutathione changes because of disease, and may be valuable in clinical trials of stroke and other neurological diseases.
TLR9 Bone Marrow Chimeric Mice Define a Role for Cerebral TNF in Neuroprotection Induced by CpG Preconditioning
Authors: Packard Amy EB , Leung Philberta Y , Vartanian Keri B , Stevens Susan L , Bahjat Frances R , Stenzel-Poore Mary P
Published: September 2012

Systemic preconditioning with the TLR9 ligand CpG induces neuroprotection against brain ischemic injury through a tumor necrosis factor (TNF)-dependent mechanism. It is unclear how systemic administration of CpG engages the brain to induce the protective phenotype. To address this, we created TLR9-deficient reciprocal bone marrow chimeric mice lacking TLR9 on either hematopoietic cells or radiation-resistant cells of nonhematopoietic origin. We report that wild-type mice reconstituted with TLR9-deficient hematopoietic cells failed to show neuroprotection after systemic CpG preconditioning. Further, while hematopoietic expression of TLR9 is required for CpG-induced neuroprotection it is not sufficient to restore protection to TLR9-deficient mice that are reconstituted with hematopoietic cells bearing TLR9. To determine whether the absence of protection was associated with TNF, we examined TNF levels in the systemic circulation and the brain. We found that although TNF is required for CpG preconditioning, systemic TNF levels did not correlate with the protective phenotype. However, induction of cerebral TNF mRNA required expression of TLR9 on both hematopoietic and nonhematopoietic cells and correlated with neuroprotection. In accordance with these results, we show the therapeutic potential of intranasal CpG preconditioning, which induces brain TNF mRNA and robust neuroprotection with no concomitant increase in systemic levels of TNF.
Pharmacokinetic–Pharmacodynamic Modeling of Severity Levels of Extrapyramidal Side Effects With Markov Elements
Authors: Pilla Reddy V , Petersson KJ , Suleiman AA , Vermeulen A , Proost JH , Friberg LE
Published: September 2012

A major problem in the treatment of schizophrenic patients with current antipsychotic drugs, mainly acting as dopamine‐2 receptor antagonists, is the occurrence of side effects such as extrapyramidal symptoms (EPS). Meta‐analyses of summary data of EPS occurrence, and receptor occupancies inferred from mean plasma concentrations, have shown the incidence of EPS to rise when receptor occupancy is above ~80%. In this analysis, individual longitudinal EPS data from 2,630 patients participating in one of seven different trials and treated with haloperidol, paliperidone, ziprasidone, olanzapine, JNJ‐37822681, or placebo were analyzed using a continuous time probability model with Markov elements. The developed pharmacokinetic–pharmacodynamic model describes the longitudinal changes of spontaneously reported EPS‐related adverse events and their severity levels rated by clinicians. Individual steady‐state concentrations and occupancy levels were found to be predictors for EPS. The results confirm 80% occupancy as a level of increased EPS occurrence rates, also at the individual level.

CPT: Pharmacometrics & Systems Pharmacology (2012) 1, e1; doi:10.1038/psp.2012.9; advance online publication 26 September 2012
The substrate/product-binding modes of a novel GH120 β-xylosidase (XylC) from Thermoanaerobacterium saccharolyticum JW/SL-YS485
Authors: Huang Chun-Hsiang , Sun Yu , Ko Tzu-Ping , Chen Chun-Chi , Zheng Yingying , Chan Hsiu-Chien , Pang Xuefei , Wiegel Juergen , Shao Weilan , Guo Rey-Ting
Published: September 2012

Xylan-1,4-β-xylosidase (β-xylosidase) hydrolyses xylo-oligomers at their non-reducing ends into individual xylose units. Recently, XylC, a β-xylosidase from Thermoanaerobacterium saccharolyticum JW/SL-YS485, was found to be structurally different from corresponding glycosyl hydrolases in the CAZy database (http://www.cazy.org/), and was subsequently classified as the first member of a novel family of glycoside hydrolases (GH120). In the present paper, we report three crystal structures of XylC in complex with Tris, xylobiose and xylose at 1.48–2.05 Å (1 Å=0.1 nm) resolution. XylC assembles into a tetramer, and each monomer comprises two distinct domains. The core domain is a right-handed parallel β-helix (residues 1–75 and 201–638) and the flanking region (residues 76–200) folds into a β-sandwich domain. The enzyme contains an open carbohydrate-binding cleft, allowing accommodation of longer xylo-oligosaccharides. On the basis of the crystal structures and in agreement with previous kinetic data, we propose that XylC cleaves the glycosidic bond by the retaining mechanism using two acidic residues Asp382 (nucleophile) and Glu405 (general acid/base). In addition to the active site, nine other xylose-binding sites were consistently observed in each of the four monomers, providing a possible reason for the high tolerance of product inhibition.