bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the cytotoxicity and genotoxicity of extracts of mussels originating from Moroccan Atlantic coast, in human colonic epithelial cells Caco‐2
Authors: Nasser Boubker , Moustaid Khadija , Moukha Serge , Mobio Théophile A. , Essamadi Abdelkhalid , Creppy Edmond E.
Published: January 2008

Industrial processing of phosphates generates chemical wastes which are, without any treatment, discharged directly into the Atlantic Ocean at Jorf Lasfar (JL), located 120 km south of Casablanca (Morocco) were shellfish are also collected by people without any control. Marine bivalves concentrate these pollutants by filtration and serve as vectors in human's exposure. The objective of this study was to test and compare in vitro on human intestinal cells (Caco‐2) the cytotoxicity and genotoxicity of mussels (Mytilus galloprovincialis) extracts (either hydrophilic or lipophilic) collected at two coastal sites; JL (neighboring a phosphate processing plat‐form) and Oualidia (OL) (a vegetable growing area) located 160 km south of Casablanca (i.e. 40 km south of JL). Using Caco‐2 cells, the following end‐points have been evaluated, cytotoxicity as measured by MTS test, inhibition of cellular macromolecules syntheses (DNA and protein) and genotoxicity evaluated by DNA fragmentation in agarose gel electrophoresis. The results indicated, that hydrophilic and lipophilic OL mussels extracts are cytotoxic and inhibit cellular macromolecules syntheses. Moreover these extracts damage the DNA in Caco‐2 cells. The lipophilic JL mussels extract is cytotoxic, inhibits cellular macromolecules syntheses, and damages the DNA in Caco‐2 cells whereas the hydrophilic extract of JL mussels fails to inhibit protein synthesis and does not damage the DNA. This extract rather enhances protein synthesis, suggesting possible metallothioneins induction by metal ions. Altogether these in vitro data indicate that mussels collected from OL could be more harmful than those from JL even though the later is closer to the pollution site than OL. Nevertheless consumption of mussels from all these areas may present a risk for humans. Epidemiological studies will be needed for global risk assessment in humans living in these areas especially those consuming see food regularly. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2008.
NTBC treatment in tyrosinaemia type I: Long‐term outcome in French patients
Authors: Masurel‐Paulet A. , Poggi‐Bach J. , Rolland M.‐O. , Bernard O. , Guffon N. , Dobbelaere D. , Sarles J. , de Baulny H. Ogier , Touati G.
Published: January 2008

We describe a retrospective study of long‐term outcome of 46 patients treated and regularly followed in France with 2‐(2‐nitro‐4‐trifluoromethylbenzoyl)‐1, 3‐cyclohexanedione (NTBC) for tyrosinaemia type I. Most had initial good response with normalization of liver function and metabolic parameters. Only one infant had no response to treatment and required liver transplantation. Among the 45 long‐term treated patients, three underwent secondary liver transplantation: one for cirrhosis and two because of hepatocellular carcinoma. One of the latter died of transplantation complications, so that the overall survival rate was 97.5%. However, 17 of 45 showed persistent abnormal liver imaging (heterogeneous liver) and 6 had cirrhosis. Furthermore, 15 had persistently elevated levels of alpha‐fetoprotein, highlighting the question of the persistent risk of carcinoma. Quality of life was usually good but compliance problems were frequent, mainly regarding the low phenylalanine–tyrosine diet. Few adverse effects were observed. A main concern was the high frequency of cognitive impairment causing schooling problems, which may be related to persistent chronic hypertyrosinaemia. In conclusion, this series confirms that NTBC treatment has clearly improved the vital prognosis and quality of life of tyrosinaemia type I patients but that many late complications persist. Long‐term studies are necessary to determine whether this drug may prevent or only delay liver complications, andto survey the possible risks of the drug. A more restricted diet could be necessary to prevent the neurological impact of the disease.
Endurance performance in masters athletes
Authors: Reaburn Peter , Dascombe Ben
Published: January 2008

Masters athletes are typically older than 35 years of age and systematically train for, and compete in, organized forms of sport specifically designed for older adults. They are motivated to participate in masters sport for a wide variety of reasons. Age-related declines in endurance performance are observed across the endurance sports of running, orienteering, rowing, and swimming. These declines are curvilinear from age 35 years until approximately age 60–70 years and exponential thereafter. The decline in endurance performance appears primarily due to an age-related decrease in VO2maxsecondary to an age-related decrease in HRmaxand possible age-related declines in stroke volume and arteriovenous oxygen difference. While performance velocity at lactate threshold decreases with age in masters endurance athletes, it appears to increase relative to VO2maxwhile exercise economy is maintained. There also appears an age-related decrease in active muscle mass, type II muscle fiber size, and blood volume that contribute to decreased endurance performance. However, research suggests that maintenance of training intensity and volume into older age may mediate the rate of age-related decline in VO2max, stroke volume, arteriovenous oxygen difference, blood volume, and muscle mass in masters endurance athletes.
Iron Oxide Nanoparticles Employed as Seeds for the Induction of Microcrystalline Diamond Synthesis
Authors: Uppireddi Kishore , Resto Oscar , Weiner Brad R , Morell Gerardo
Published: January 2008

Iron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. X-ray diffraction, visible, and ultraviolet Raman Spectroscopy, energy-filtered transmission electron microscopy , electron energy-loss spectroscopy, and X-ray photoelectron spectroscopy (XPS) were employed to study the carbon bonding nature of the films and to analyze the carbon clustering around the seed nanoparticles leading to diamond synthesis. The results indicate that iron oxide nanoparticles lose the O atoms, becoming thus active C traps that induce the formation of a dense region of trigonally and tetrahedrally bonded carbon around them with the ensuing precipitation of diamond-type bonds that develop into microcrystalline diamond films under chemical vapor deposition conditions. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.
Combining Results of Two GC Separations Partly Achieves Determination of All cis and trans 16:1, 18:1, 18:2 and 18:3 Except CLA Isomers of Milk Fat as Demonstrated Using Ag‐Ion SPE Fractionation
Authors: Kramer John K. G. , Hernandez Marta , Cruz‐Hernandez Cristina , Kraft Jana , Dugan Michael E. R.
Published: January 2008

Milk fat is a complex mixture of geometric and positional isomers of monounsaturated and polyunsaturated, including short‐, long‐ and branch‐chain fatty acids (FAs). There has been partial success to resolve this mixture of FAs using different GC temperature programs, or a combination of GC isothermal and temperature programs. To overcome the problem associated with overlapping isomers prior silver‐ion separation was recommended. However, this procedure is time consuming and not practical for routine analysis. In addition, previous methods focused mainly on the trans and cis isomers of 18:1. The present method takes advantage of differences in the relative elution times between different types of FAs. The method involved analyzing each milk fat using the same highly polar 100‐m capillary column and GC instrument, and conducting two separations using temperature programs that plateau at 175 and 150 °C. The relative shift among the geometric and positional isomers at these two temperature settings was enough to permit identification of most of the trans and cis 16:1, 18:1 and 20:1, the c/t‐18:2 and the c/c/t‐18:3 isomers found in milk fat. The identity of these FAs was confirmed by prior separation of the total fatty acid methyl esters (FAMEs) of milk fat using Ag+‐SPE columns, and comparing the fractions to the total milk fat. The Ag+‐SPE technique was modified to obtain pure saturated, trans‐ and cis‐monounsaturated and diunsaturated FAMEs. By combining the results from these two separate GC analyses, knowing the elution order, it was possible to determine most of the geometric and positional isomers of 16:1, 18:1, 20:1, 18:2 and 18:3 without a prior silver‐ion separation. Only few minor FAs could not be resolved, notable the conjugated linoleic acid isomers that still required the complimentary Ag+‐HPLC separation. The two GC temperature programs have been successfully used to routinely analyze most FA isomers in total milk and beef fats in about 200 min without the use of prior silver‐ion separations.
Santaluminsulare Acetylenic Fatty Acid Seed Oils: Comparison within the Santalum Genus
Authors: Butaud J.‐F. , Raharivelomanana P. , Bianchini J.‐P. , Gaydou E. M.
Published: January 2008

The sandalwood kernels of Santalum insulare (Santalaceae) collected in French Polynesia give seed oils containing significant amounts of ximenynic acid, E‐11‐octadecen‐9‐oic acid (64–86%). Fatty acid (FA) identifications were performed by gas chromatography/mass spectrometry (GC/MS) of FA methyl esters. Among the other main eight identified fatty acids, oleic acid was found at a 7–28% level. The content in stearolic acid, octadec‐9‐ynoic acid, was low (0.7–3.0%). An inverse relationship was demonstrated between ximenynic acid and oleic acid using 20 seed oils. Results obtained have been compared to other previously published data on species belonging to the Santalum genus, using multivariate statistical analysis. The relative FA S. insulare composition, rich in ximenynic acid is in the same order of those given for S. album or S. obtusifolium. The other compared species (S. acuminatum, S. lanceolatum, S. spicatum and S. murrayanum) are richer in oleic acid (40–59%) with some little differences in linolenic content.
Invasive pneumococcal and meningococcal disease: association with influenza virus and respiratory syncytial virus activity?
Authors: JANSEN A. G. S. C. , SANDERS E. A. M. , VAN DER ENDE A. , VAN LOON A. M. , HOES A. W. , HAK E.
Published: January 2008

Few studies have examined the relationship between viral activity and bacterial invasive disease, considering both influenza virus and respiratory syncytial virus (RSV). This study aimed to assess the potential relationship between invasive pneumococcal disease (IPD), meningococcal disease (MD), and influenza virus and RSV activity in The Netherlands. Correlations were determined between population-based data on IPD and MD during 1997–2003 and influenza virus and RSV surveillance data. Incidence rate ratios of disease during periods of high influenza virus and RSV activity over the peri-seasonal and summer baseline periods were calculated. The analyses comprised 7266 and 3072 cases of IPD and MD. When data from all seasons were included, the occurrence of pneumococcal bacteraemia and MD correlated significantly with influenza virus and RSV activity both in children and adults. Periods of increased influenza virus and RSV activity showed higher rates of pneumococcal bacteraemia in older children and adults than the peri-season period. Rates of MD in children were also higher during periods of increased influenza virus activity; the same appeared true for MD in older children during periods of increased RSV activity. Although no causal relationship may be inferred from these data, they support a role for influenza virus and RSV in the pathogenesis of IPD and MD.
Sporadic community-acquired Legionnaires' disease in France: a 2-year national matched case-control study
Authors: CHE D. , CAMPESE C. , SANTA-OLALLA P. , JACQUIER G. , BITAR D. , BERNILLON P. , DESENCLOS J.-C.
Published: January 2008

Legionnaires' disease (LD) is an aetiology of community-acquired bacterial pneumonia in adults, with a high case-fatality ratio (CFR). We conducted a matched case-control study to identify risk factors for sporadic, community-acquired LD. Cases of sporadic, community-acquired and biologically confirmed LD, in metropolitan France from 1 September 2002 to 31 September 2004, were matched with a control subject according to age, sex, underlying illness and location of residence within 5 km. We performed a conditional logistic regression on various host-related factors and exposures. Analysis was done on 546 matched pairs. The CFR was 3·5%. Age ranged from 18–93 years (mean 57 years), with a 3·6 male:female sex ratio. Cases were more likely to have smoked with the documentation of a dose-effect relation, to have travelled with a stay in a hotel (OR 6·1, 95% CI 2·6–14·2), or to have used a wash-hand basin for personal hygiene (OR 3·5, 95% CI 1·6–7·7) than controls. Tobacco and travel have been previously described as risk factors for LD, but this is the first time that such a dose-effect for tobacco has been documented among sporadic cases. These findings will provide helpful knowledge about LD and help practitioners in identifying patients at high risk.
Lichen species density and abundance over ten years in permanent plots in inland Dronning Maud Land, Antarctica
Authors: Johansson Per , Thor Göran
Published: January 2008

In the austral summer of 1991–92, 120 sample plots were established along 11 transects at various distances from the Swedish research stations Wasa and Svea in Dronning Maud Land, Antarctica. These plots were re-examined in 2001–02 to evaluate overall changes and possible local impact from human activities around the research stations on the terrestrial vegetation, formed by lichens and mosses. The results showed high consistencies over the ten years, but nevertheless suggest a slight overall increase in both lichen species density and abundance, measured as the number of lichen records. We did not find evidence for any severe human impact on the lichens and mosses around the research stations. However, sample plots located close to the Svea station had been affected by station maintenance, which has caused local decline of lichen species such as Umbilicaria decussata. In contrast to the overall consistency and slight increase in lichens we found a decline of Rhizoplaca melanophthalma.
Age composition and feeding ecology of early juvenile Notothenia rossii (Pisces, Nototheniidae) at Potter Cove, South Shetland Islands, Antarctica
Authors: Barrera-Oro Esteban R. , Winter Debora J.
Published: January 2008

Age and diet of 140 brown phase early juvenile Notothenia rossii specimens caught at Potter Cove from December 2005–March 2006 were studied. Fish were immature, in the range 8.5–21 cm TL and of age groups 1–2 (otolith/scale readings). The diet (F% and coefficient Q methods) was mainly benthic-demersal organisms with Gammaridean amphipods (primarily Gondogeneia antarctica) as the most frequent (F% = 98) and main prey (Q% = 97). The occurrence of algae, gastropods and harpacticoid copepods was high, but these organisms were secondary or occasional food. The importance of other benthic (bivalves, polychaetes, isopods) and pelagic (ostracods, calanoids, hyperiid amphipods, krill) prey was very low. Preference of larger fish for larger prey was evident. Stomach fullness analysis showed high food availability during the sampling period. Young stages of N. rossii are demersal, preying mainly on gammarideans and other invertebrates of the benthic community associated with macroalgae beds. The almost complete lack of plankton components in the diet of early juvenile fish suggests they do not migrate vertically to feed.
Population subdivision in the Antarctic toothfish (Dissostichus mawsoni) revealed by mitochondrial and nuclear single nucleotide polymorphisms (SNPs)
Authors: Kuhn Kristen L. , Gaffney Patrick M.
Published: January 2008

The Antarctic toothfish (Dissostichus mawsoni) exhibits a circumpolar distribution in coastal waters south of the Antarctic Polar Front. For a preliminary evaluation of global population structure in this species, we examined four mitochondrial regions and 13 nuclear gene fragments in samples from four CCAMLR Subareas in the Southern Ocean (Australian Antarctic Territory (Subarea 58.4.2), Ross Dependency (Subareas 88.1 and 88.2) and the South Shetland Islands (Subarea 48.1). Significant genetic differentiation within and among locations was observed for both mitochondrial and nuclear loci. The single nucleotide polymorphism (SNP) markers developed here will be useful for more extensive analyses of population structure in this species.
Sensitivity to eye gaze in autism: Is it normal? Is it automatic? Is it social?
Authors: Nation Kate , Penny Sophia
Published: January 2008

Children with autism are developmentally delayed in following the direction of another person's gaze in social situations. A number of studies have measured reflexive orienting to eye gaze cues using Posner-style laboratory tasks in children with autism. Some studies observe normal patterns of cueing, suggesting that children with autism are alert to the significance of the eyes, whereas other studies reveal an atypical pattern of cueing. We review this contradictive evidence to consider the extent to which sensitivity to gaze is normal, and ask whether apparently normal performance may be a consequence of atypical (nonsocial) mechanisms. Our review concludes by highlighting the importance of adopting a developmental perspective if we are to understand the reasons why people with autism process eye gaze information atypically.
Longitudinal relations between parental drinking problems, family functioning, and child adjustment
Authors: Keller PEGGY S. , Cummings E. Mark , Davies Patrick T. , Mitchell Patricia M.
Published: January 2008

Relations between maternal and paternal problem drinking symptoms and destructive marital conflict, parenting problems, and children's internalizing and externalizing problems were investigated. Participants were community families with a child in kindergarten who completed questionnaire measures at baseline (N = 235), 1 year later (N = 227), and 2 years later (N = 215). Structural equation modeling revealed that paternal problem drinking at Time 1 was associated with greater destructive marital conflict 1 year later. In turn, destructive marital conflict was related to decreased parental warmth and increased parental psychological control; these parenting problems were associated with greater child internalizing and externalizing problems at the third time point. Further analyses revealed that the indirect effects of paternal drinking on children's adjustment were significant, and that relations remained even after including autoregressive effects. Findings are discussed in terms of family process models for relations between parental drinking and child adjustment problems.
True and false recall and dissociation among maltreated children: The role of self-schema
Authors: Valentino Kristin , Cicchetti Dante , Rogosch Fred A. , Toth Sheree L.
Published: January 2008

The current investigation addresses the manner through which trauma affects basic memory and self-system processes. True and false recall for self-referent stimuli were assessed in conjunction with dissociative symptomatology among abused (N= 76), neglected (N= 92), and nonmaltreated (N= 116) school-aged children. Abused, neglected, and nonmaltreated children did not differ in the level of processing self-schema effect or in the occurrence and frequency of false recall. Rather, differences in the affective valence of false recall emerged as a function of maltreatment subtype and age. Regarding dissociation, the abused children displayed higher levels of dissociative symptomatology than did the nonmaltreated children. Although abused, neglected, and nonmaltreated children did not exhibit differences in the valence of their self-schemas, positive and negative self-schemas were related to self-integration differently among the subgroups of maltreatment. Negative self-schemas were associated with increased dissociation among the abused children, whereas positive self-schemas were related to increased dissociation for the neglected children. Thus, positive self-schemas displayed by the younger neglected children were related to higher dissociation, suggestive of defensive self-processing. Implications for clinical intervention are underscored.
Parental imprisonment: Long-lasting effects on boys' internalizing problems through the life course
Authors: Murray Joseph , Farrington David P.
Published: January 2008

Qualitative studies suggest that children react to parental imprisonment by developing internalizing as well as externalizing behaviors. However, no previous study has examined the effects of parental imprisonment on children's internalizing problems using standardized instruments, appropriate comparison groups, and long-term follow-up. Using prospective longitudinal data from the Cambridge Study in Delinquent Development, we compared boys separated because of parental imprisonment during their first 10 years of life with four control groups: boys who did not experience separation, boys separated because of hospitalization or death, boys separated for other reasons (usually parental disharmony), and boys whose parents were only imprisoned before the boys' births. Individual, parenting, and family risk factors for internalizing problems were measured when boys were ages 8–11 years. Separation because of parental imprisonment predicted boys' internalizing problems from age 14 to 48, even after controlling for childhood risk factors including parental criminality. Separation because of parental imprisonment also predicted the co-occurrence of internalizing and antisocial problems. These results suggest that parental imprisonment might cause long-lasting internalizing and antisocial problems for children.
Does adolescent self-esteem predict later life outcomes? A test of the causal role of self-esteem
Authors: Boden Joseph M. , Fergusson David M. , Horwood L. John
Published: January 2008

This paper examines the relationship between self-esteem in adolescence and later mental health, substance use, and life and relationship outcomes in adulthood. The investigation analyzed data from a birth cohort of approximately 1,000 New Zealand young adults studied to the age of 25. Lower levels of self-esteem at age 15 were associated with greater risks of mental health problems, substance dependence, and lower levels of life and relationship satisfaction at ages 18, 21, and 25. Adjustment for potentially confounding factors reduced the strength of these associations to either moderate or statistically nonsignificant levels. It was concluded that the effects of self-esteem during adolescence on later developmental outcomes were weak, and largely explained by the psychosocial context within which self-esteem develops.
A neurocognitive model of borderline personality disorder: Effects of childhood sexual abuse and relationship to adult social attachment disturbance
Authors: Minzenberg Michael J. , Poole John H. , Vinogradov Sophia
Published: January 2008

Borderline personality disorder (BPD) is a paradigmatic disorder of adult attachment, with high rates of antecedent childhood maltreatment. The neurocognitive correlates of both attachment disturbance and maltreatment are both presently unknown in BPD. This study evaluated whether dimensional adult attachment disturbance in BPD is related to specific neurocognitive deficits, and whether childhood maltreatment is related to these dysfunctions. An outpatient BPD group (n= 43) performed nearly 1SDbelow a control group (n= 26) on short-term recall, executive, and intelligence functions. These deficits were not affected by emotionally charged stimuli. In the BPD group, impaired recall was related to attachment–anxiety, whereas executive dysfunction was related to attachment–avoidance. Abuse history was correlated significantly with executive dysfunction and at a trend level with impaired recall. Neurocognitive deficits and abuse history exhibited both independent and interactive effects on adult attachment disturbance. These results suggest that (a) BPD patients' reactivity in attachment relationships is related to temporal–limbic dysfunction, irrespective of the emotional content of stimuli, (b) BPD patients' avoidance within attachment relationships may be a relational strategy to compensate for the emotional consequences of frontal-executive dysregulation, and (c) childhood abuse may contribute to these neurocognitive deficits but may also exert effects on adult attachment disturbance that is both independent and interacting with neurocognitive dysfunction.
Seasonal variations of carbon isotopic composition of methane from Indian paddy fields
Authors: Rao D. K. , Bhattacharya S. K. , Jani R. A.
Published: January 2008

Systematic measurements of methane (CH4) flux and δ13C of methane from two paddy fields, one each from southern and western India, were carried out. There is a significant variation in δ13C values of methane emitted during the entire season. The estimated annual emission rates of methane for the above two paddy fields are 16 and 9 g m−2, respectively, which are in good agreement with methane flux values reported for paddy fields in the neighboring regions within India. Methane emitted in the beginning of the growing season is relatively enriched in 13C, then depleted before harvesting, and finally enriched again at the end of season. Seasonal changes in δ13C of methane are probably due to changes in methane production, oxidation, and fractionation associated with transport. The flux‐weighted annual average values of δ13C are calculated to be −54.3‰ and −57.2‰ for the two investigated paddy fields, which are more enriched compared to that for paddy fields in Japan, China, and Italy.
Multiple cusps during an extended northward IMF period with a significant By component
Authors: Zong Q.‐G. , Zhang H. , Fritz T. A. , Goldstein M. L. , Wing S. , Keith W. , Winningham J. D. , Frahm R. , Dunlop M. W. , Korth A. , Daly P. W. , Rème H. , Balogh A. , Fazakerley A. N.
Published: January 2008

On 21–22 March 2001, four cusp‐like regions were observed consecutively in about five hours by all four Cluster spacecraft when the interplanetary magnetic field (IMF) was northward with a significant By component. All four cusp‐like encounters were characterized by turbulent magnetic fields, high‐density plasma, and plasma flow significantly slower than the magnetosheath level. The cusp‐like regions are associated with thermalized, bidirectional distributed plasma electrons. The first encountered cusp is the main cusp; the other three cusp‐like regions are temporal effects. The normal velocities vn at boundary interfaces (exit from the cusp) are found to be almost three times larger than that at boundary interfaces (entry into the cusp). The boundary normal, velocity, and timing analysis for six clear boundaries of the last three cusps obtained by all four spacecraft indicates that they are most likely one boundary shifting in the dawn‐dusk direction between the dayside magnetosphere/trapping region and the cusp region. So the Cluster spacecraft have been observing the same cusp, and it appeared as four cusp‐like regions due to possible magnetospheric oscillations. Oscillations with a period of 22 min are observed by the Cluster spacecraft in the high‐latitude region, which is in agreement with the cold‐dense plasma sheet fluctuations (20 min period) observed by the Geotail satellite. Multiple cusps observed by Cluster and the wavy‐like structures in the dusk low‐latitude boundary layer observed by Geotail simultaneously suggest the whole magnetosphere is oscillating during northward IMF.
Northerly surface winds over the eastern North Pacific Ocean in spring and summer
Authors: Taylor Stephen V. , Cayan Daniel R. , Graham Nicholas E. , Georgakakos Konstantine P.
Published: January 2008

Persistent spring and summer northerly surface winds are the defining climatological feature of the western coast of North America, especially south of the Oregon coast. Northerly surface winds are important for upwelling and a vast array of other biological, oceanic, and atmospheric processes. Intermittence in northerly coastal surface wind is characterized and wind events are quantitatively defined using coastal buoy data south of Cape Mendocino on the northern California coast. The defined wind events are then used as a basis for composites in order to explain the spatial evolution of various atmospheric and oceanic processes. Wind events involve large‐scale changes in the three‐dimensional atmospheric circulation including the eastern North Pacific subtropical anticyclone and southeast trade winds. Composites of QSCAT satellite scatterometer wind estimates from 1999 to 2005 based on a single coastal buoy indicate that wind events typically last 72–96 h and result in anomalies in surface wind and Ekman pumping that extend over 1000 km from the west coast of North America. It may be useful to consider ocean circulation and dependent ecosystem dynamics and the distribution of temperature, moisture, and aerosols in the atmospheric boundary layer in the context of wind events defined herein.
Paleomagnetic reorientation of San Andreas Fault Observatory at Depth (SAFOD) core
Authors: Parés Josep M. , Schleicher Anja M. , van der Pluijm Ben A. , Hickman Stephen
Published: January 2008

We present a protocol for using paleomagnetic analysis to determine the absolute orientation of core recovered from the SAFOD borehole. Our approach is based on determining the direction of the primary remanent magnetization of a spot core recovered from the Great Valley Sequence during SAFOD Phase 2 and comparing its direction to the expected reference field direction for the Late Cretaceous in North America. Both thermal and alternating field demagnetization provide equally resolved magnetization, possibly residing in magnetite, that allow reorientation. Because compositionally similar siltstones and fine‐grained sandstones were encountered in the San Andreas Fault Zone during Stage 2 rotary drilling, we expect that paleomagnetic reorientation will yield reliable core orientations for continuous core acquired from directly within and adjacent to the San Andreas Fault during SAFOD Phase 3, which will be key to interpretation of spatial properties of these rocks.
Geomagnetic field intensity behavior in the Middle East between ∼3000 BC and ∼1500 BC
Authors: Gallet Yves , Le Goff Maxime , Genevey Agnès , Margueron Jean , Matthiae Paolo
Published: January 2008

An archeointensity study was carried out on 14 sites of Syrian baked clay artifacts, archeologically dated between ∼2500 BC and ∼1600 BC. Using an experimental protocol involving high‐temperature magnetization measurements, well‐defined mean intensity values were derived for 13 different sites with three to nine results obtained at the fragment level per site. Results of similar ages are coherent and the new data set is in good agreement with previous archeointensity results obtained from the same region. All together these data allow one to refine the evolution of the geomagnetic field intensity in the Middle East during the third and the second millennium BC. In particular, they show the occurrence of three periods of rather sharp intensity increase at ∼2600 BC, ∼2200 BC and ∼1600 BC possibly at the times of climatic cooling in the eastern North Atlantic, further suggesting a connection between the Earth's magnetic field and multi‐decadal climatic events.
Record of δ18O and 17O‐excess in ice from Vostok Antarctica during the last 150,000 years
Authors: Landais Amaelle , Barkan Eugeni , Luz Boaz
Published: January 2008

We measured δ17O and δ18O in recent Antarctic snow and down the Vostok ice core and calculated the excess of 17O with respect to VSMOW. The magnitude of the 17O excess in the Holocene and the last interglacial is ∼45 per meg, and it remains constant in a transect from the coast to the continental interior. Analysis of the transect data shows that the 17O‐excess is not sensitive to temperature variations over the continent. There are significant shifts in 17O‐excess from low values in glacial to high values in interglacial times. The observed shifts suggest higher normalized relative humidity and/or wind speeds over the source oceanic regions in glacial times.
A preliminary tidal analysis of ICESat laser altimetry: Southern Ross Ice Shelf
Authors: Ray R. D.
Published: January 2008

Satellite laser altimetry could soon play a key role in mapping poorly known ocean tides underneath Antarctic ice shelves. The amount of ICESat data now collected over the southernmost part of the Ross Ice Shelf is sufficient to warrant direct tidal analysis. Tides are estimated here from ten operational ICESat periods, totaling 363 days. A response analysis helps overcome unfavorable tidal sampling, especially an S2 correlation with the annual cycle. Comparisons of tidal estimates against independent station data show RMS constituent differences around 3 cm—still somewhat large, but an encouraging result for such a challenging region.
Temperature trends derived from Stratospheric Sounding Unit radiances: The effect of increasing CO2 on the weighting function
Authors: Shine Keith P. , Barnett John J. , Randel William J.
Published: January 2008

Stratospheric Sounding Units (SSU) on the NOAA operational satellites have been the main source of near‐global temperature trend data above the lower stratosphere. They have been used extensively for comparison with model‐derived trends. The SSU senses in the 15 μm band of CO2 and hence the weighting function is sensitive to changes in CO2 concentrations. The impact of this change in weighting function has been ignored in all recent trend analyses. We show that the apparent trends in global‐mean brightness temperature due to the change in weighting function vary from about −0.4 Kdecade−1 to 0.4 Kdecade−1, depending on the altitude sensed by the different SSU channels. For some channels, this apparent trend is of a similar size to the trend deduced from SSU data but ignoring the change in weighting function. In the mid‐stratosphere, the revised trends are now significantly more negative and in better agreement with model‐calculated trends.
Global warming and United States landfalling hurricanes
Authors: Wang Chunzai , Lee Sang‐Ki
Published: January 2008

A secular warming of sea surface temperature occurs almost everywhere over the global ocean. Here we use observational data to show that global warming of the sea surface is associated with a secular increase of tropospheric vertical wind shear in the main development region (MDR) for Atlantic hurricanes. The increased wind shear coincides with a weak but robust downward trend in U.S. landfalling hurricanes, a reliable measure of hurricanes over the long term. Warmings over the tropical oceans compete with one another, with the tropical Pacific and Indian Oceans increasing wind shear and the tropical North Atlantic decreasing wind shear. Warmings in the tropical Pacific and Indian Oceans win the competition and produce increased wind shear which reduces U.S. landfalling hurricanes. Whether future global warming increases the vertical wind shear in the MDR for Atlantic hurricanes will depend on the relative role induced by secular warmings over the tropical oceans.
Global model comparison with Millstone Hill during September 2005
Authors: Pawlowski David J. , Ridley Aaron J. , Kim Insung , Bernstein Dennis S.
Published: January 2008

A direct comparison between simulation results from the Global Ionosphere Thermosphere Model (GITM) and measurements from the Millstone Hill incoherent scatter radar (ISR) during the month of September 2005 is presented. Electron density, electron temperature, and ion temperature results are compared at two altitudes where ISR data is the most abundant. The model results are produced, first using GITM running in one dimension, which allows comparison at the Millstone Hill location throughout the entire month. The model results have errors ranging from 20% to 50% over the course of the month. In addition, the F2 peak electron density (NmF2) and height of the peak (HmF2) are compared for the month. On average the model indicates higher peak electron densities as well as a higher HmF2. During the time period from 9 September through 13 September, the trends in the data are different than the trends in the model results. These differences are due to active solar and geomagnetic conditions during this time period. Three‐dimensional (3‐D) GITM results are presented during these active conditions, and it is found that the 3‐D model results replicate the trends in the data more closely. GITM is able to capture the positive storm phase that occurred late on 10 September but has the most difficulty capturing the density depletion on 11 and 12 September that is seen in the data. This is probably a result of the use of statistical high‐latitude and solar drivers that are not as accurate during storm time.
Electron flat‐top distributions around the magnetic reconnection region
Authors: Asano Y. , Nakamura R. , Shinohara I. , Fujimoto M. , Takada T. , Baumjohann W. , Owen C. J. , Fazakerley A. N. , Runov A. , Nagai T. , Lucek E. A. , Rème H.
Published: January 2008

Cluster multisatellite observations provide snapshots of electron distributions around the magnetic neutral line. An isotropic flat‐top‐type electron distribution in phase space is frequently observed around the X line, together with large ion velocities and a Hall quadrupole‐like magnetic field inside the hot and tenuous plasma sheet in the magnetotail. The flat‐top distributions are also associated with a finite magnetic field in the direction normal to the neutral sheet, and the cross‐tail current density is sometimes very small. These results indicate that the flat‐top‐type distribution is mainly located near the outer boundary of the ion diffusion region in the plasma sheet outflow region, before reaching the pileup region with large normal component of the magnetic field. Simultaneously with the flat‐top distributions, strong field‐aligned electron beams mainly toward the X line are occasionally observed. This type of beam is mainly observed in the off‐equatorial plasma sheet and also appears well inside the plasma sheet. Typical energies of the beam are 4–10 keV, which is comparable to the upper edge of flat‐top energy. These highly accelerated electron distributions have a steep decrease in phase space density at the high‐energy end, and it is found that they are not correlated with the increase of the higher‐energy electrons related to suprathermal acceleration (>30 keV). This result indicates that the electron acceleration processes for the flat‐top‐type distributions are different from the suprathermal components, both of which are beyond the conventional MHD outflow acceleration and considered to be associated with some kinetic processes.
Ground based observations of low frequency auroral hiss fine structure
Authors: Ye S. , LaBelle J.
Published: January 2008

An electric field waveform receiver, operated at South Pole Station during 2004, recorded numerous low‐frequency (LF) auroral hiss events, revealing fine structures which fall into three categories, in order of occurrence rate: patchy/continuous features, which have wide bandwidth (100s of kHz) and slow time variation (of order 1 s or longer); vertical/impulsive features, which have wide bandwidth (100s of kHz) and short duration (≪1 s); and discrete features, which have narrow bandwidths (100s of Hz to a few kHz) and a range of durations. We investigate two possible generation mechanisms for the discrete features. First, they may arise from mode conversion of narrowband Langmuir waves generated where the discrete feature frequency matches the plasma frequency in the auroral ionosphere. In fact, the estimated source power of narrowband discrete whistler modes observed in recent sounding rocket experiments and the estimated source power of the discrete features observed at South Pole station are ordered in the manner expected if mode conversion of Langmuir waves accounts for each of these observations. Second, Sonwalkar and Harikumar (2000) propose that auroral hiss must mode convert on meter‐scale density irregularities in order to gain access to ground level; we put forth that if the meter‐scale irregularities are highly monochromatic, the resulting mode‐converted whistler modes that reach the ground will be composed of narrow‐band discrete features. Ray‐tracing studies in a model auroral ionosphere suggest that scattering from 10–100 m irregularities could account for the fine structures in the LF auroral hiss observed at South Pole Station.
New description of Io's cold plasma torus
Authors: Herbert Floyd , Schneider Nicholas M. , Dessler A. J.
Published: January 2008

Despite more than 25 years of study of the Io plasma torus, its generation, dynamics, and even its spatial structure are still poorly understood, especially in the case of the inner, cold region of the torus. To remedy this lack, we analyzed ground‐based coronagraphic images of the torus in S+ 6371 Å emission. We derived cold torus properties by modeling and removing these images' inherent line‐of‐sight integration and atmospheric blurring, using new deconvolution techniques, obtaining high‐spatial‐resolution estimates of the three‐dimensional (3‐D) S+ distributions. From these 3‐D distributions, we discovered that the cold torus is washer‐shaped, with a roughly constant vertical thickness ≤0.25 Jovian radius (RJ), and a radial width that varies from 0.6 to 0.9 RJ. The cold torus is separated by a 0.1–0.2 RJ‐wide low‐density region, or “gap,” from the “ribbon” region which lies just outside it. The small, approximately constant washer height implies an ion parallel temperature (T∥) of ∼3 eV, compared with a ribbon T∥ that varies from about 20 to 50 eV as a function of Jovian magnetic longitude (λIII). The washer has a distinct inner edge, not seen before, whose jovicentric distance varies with λIII so as to create the variable cold torus width. Thus this inner edge is concentric with neither Jupiter nor the rest of the torus. We also confirm the existence of a tilt between the midplanes of the ribbon and cold torus, with an orientation that cannot be produced by the magnetic mirror force acting on ion temperature anisotropy. The structure and composition of the gap and cold torus are best explained by a model in which a small amount of warm S+ plasma diffuses inwards while radiatively cooling. While still warm, its distribution over a large scale height keeps its density small, forming the gap. After sufficient cooling, it collapses to the centrifugal equator, where its higher density and continued inward diffusion make it more visible as the cold torus washer. However, its low electron temperature (probably ≤ T∥) must be kept from further decline by a hitherto‐unsuspected energy source that powers the observed visible wavelength radiation from the cold torus and fluctuates on timescales less than the plasma diffusion time. The formation of the abrupt cold torus inner edge might indicate the loss there of either this energy source or the plasma itself.
Test particle simulations of the effect of moving DLs on ion outflow in the auroral downward‐current region
Authors: Hwang K.‐J. , Ergun R. E. , Andersson L. , Newman D. L. , Carlson C. W.
Published: January 2008

Test particle simulations of ion outflow in the auroral downward‐current region are carried out to investigate the effect of a series of highly localized, moving double layers. Double layers (DLs) have been observed in the downward‐current region, but may not be the only source of electron acceleration. However, when present, they may dramatically affect ion outflow. In the simulation the double layers (DLs) move anti‐earthward along the magnetic field (B) at the ion‐acoustic speed and are assigned a perpendicular ion heating profile along B that moves with them. The DL speed and the associated ion heating profile are based on in situ observations and dynamic simulations. This configuration greatly changes the mechanism of the ion outflow in the downward‐current region from the classical ion‐pressure cooker picture. In the moving DL model, a majority of out‐flowing ions do not pass through the DL. Instead, the ions tend to be pushed in front of a DL or trapped between two DLs which enforce outward motion and result in a significant increase in net number and energy fluxes of upgoing ions. The ion distributions from the simulations compare well to FAST observations as a function of the relative distance from the DL position along B.
Structure and growth of the Izu‐Bonin‐Mariana arc crust: 1. Seismic constraint on crust and mantle structure of the Mariana arc–back‐arc system
Authors: Takahashi Narumi , Kodaira Shuichi , Tatsumi Yoshiyuki , Kaneda Yoshiyuki , Suyehiro Kiyoshi
Published: January 2008

A high‐resolution seismic velocity model is presented for the crust and upper mantle of the Mariana arc–back‐arc system (MABS) based on active source seismic profiling. The major characteristics are (1) slow mantle velocity of <8 km s−1 in the uppermost mantle, especially, and deep reflectors under the Mariana arc (MA) and the West Mariana Ridge (WMR), (2) a deep reflector in the upper mantle beneath the relative thick crust of the Mariana Trough (MT) axis, (3) distribution of lower‐velocity lower crusts (6.7–6.9 km s−1) beneath the volcanic front and adjacent to the MT, and (4) high‐velocity lower crust (7.2–7.4 km s−1) beneath the boundary regions between the MA and MT, and between the WMR and the Parece Vela Basin (PVB), adding to structural characteristics of crust and upper mantle beneath the MABS. Of the characteristics described above, characteristic 1 suggests that the origins of the slow mantle velocity and the deep reflectors be explained by transfer of the lower crustal residues to the upper mantle across the Moho, considering that the WMR is extinct arc currently. On the other hand, characteristic 2 suggests that the origin of deep reflectors beneath the MT axis might be lower velocity materials due to the diffractive signals with strong amplitudes, characteristic 3 suggests that the lower‐velocity lower crust advanced crustal growth and characteristic 4 suggests that the high‐velocity lower crust beneath arc–back‐arc transition zone is composed of mafic/ultramafic materials created by extensive partial melting of mantle peridotites or last stage of the arc magmatism rather than serpentinized peridotite.