bluuebunny/crossref_metadata_2025 huggingface dataset:
The Experiences and Effects of Economic Status Among Racial and Ethnic Minorities
Authors: CHONG DENNIS , KIM DUKHONG
Published: September 2007

We propose and test a theory of opportunities that explains the conditions in which economic status affects support for racial and ethnic group interests among African Americans, Latinos, and Asian Americans. Using data from a 2001 Washington Post/Kaiser Family Foundation/Harvard University national survey, our analysis finds that, for all minority groups, the effect of economic status on support for group interests is mediated by the socioeconomic experiences of individuals. Intergroup differences therefore result from varying experiences and perceptions of discrimination among minority groups rather than from group-specific theoretical processes. Compared to Latinos and Asian Americans, African Americans are least responsive to changes in economic circumstances because they are on the whole more pessimistic about their life prospects and more likely to encounter discrimination. But we find in general that, among those minority individuals who perceive equal opportunity and experience less discrimination, higher economic status often leads to a reduced emphasis on race and ethnicity. These results demonstrate that the incorporation of a minority group into American society depends not only on the actions of group members but also on the fair treatment of that group by the majority population.
When Can Mediators Build Trust?
Authors: KYDD ANDREW H.
Published: September 2007

Mediation is one of the most widespread techniques for preventing conflict and promoting cooperation. I examine the conditions under which mediators can facilitate cooperation by building trust between two parties. Assuming mediators have no intrinsic commitment to honesty, they can be credible trust builders in one-round interactions only if they care about the issue at stake, have a moderate ideal point, and do not find conflict to be too costly. A mediator that is solely interested in promoting cooperation, or one that is biased toward one side, will be ineffective. A desire to preserve a reputation for honesty can overcome a limited amount of bias or issue indifference.
In search of the ‘true prospect’: making and knowing the Giant's Causeway as a field site in the seventeenth century
Authors: KENNEDY ALASDAIR
Published: September 2007

The phenomenon of the Giant's Causeway in the north of Ireland has attracted much attention over five centuries. This essay recounts the formative years between 1688 and 1708 of the Giant's Causeway as a field site and ‘philosophical landscape’ in the light of recent research on the historical geographies of scientific knowledge. This research has provided new perspectives on field science, emphasizing the spatial character of the field and its discursive formation in different spaces. A view of the field as a self-contained unit in which science is practised is rendered problematic. Instead, it is seen as part of a network of intersecting locales within which scientists and science circulate. This essay draws upon this work, exploring and mapping the spaces and techniques used by late seventeenth-century natural philosophers in London and Dublin to generate observational and conceptual knowledge of the Giant's Causeway. In doing so, the paper contributes to an understanding of the spaces of natural philosophy in the seventeenth century, of the knowledge networks within which the virtuosi operated and of the earth science field site.
“In the Public Interest”: Forced Evictions, Land Rights and Human Development in Africa
Authors: Ocheje Paul D
Published: September 2007

This article discusses the phenomenon of forced evictions in Africa and the implications for land rights and human development. It argues that the “public interest“ justification often proffered for forced evictions by African governments is a myth. The article proposes three alternative explanations for forced evictions: (a) antiquated and inappropriate planning laws of colonial origin; (b) corruption; and (c) failure of development and land reforms. The escalating urban and rural land crises in Africa, the article argues, violate human rights with grave implications for human development and regional security. The article concludes by proposing a new policy direction based on participatory and more inclusive principles.
Tenure Security: Wishful Policy Thinking or Reality? A Case from Peri-Urban Ghana
Authors: Ubink Janine M
Published: September 2007

Many areas in Africa facing land shortage and competition witness increasingly restricted and insecure access to land for the poor majority. Mounting evidence of reduced tenure security shows that customary systems are often unable to evolve equitably. In contrast with this crisis in customary land administration, current international land policy is witnessing renewed interest in customary tenure systems. Ghana's current land policy resonates with this international trend. This article focuses on peri-urban Kumasi, Ghana, to acquire an insight into struggles and negotiations over customary land tenure in a rapidly urbanizing area. It then tries to explain why policymakers, in Ghana and in general, do not yet seem to have reflected the crisis in customary land management in their policies. The article concludes with some recommendations as to how policymakers could respond.
Evolving concepts of laryngeal paralysis
Authors: Woodson G
Published: September 2007

Accepted concepts of the pathophysiology and treatment of laryngeal paralysis have changed over the years. It has long been observed that symptoms of laryngeal paralysis vary greatly, both between patients and over time. There have been various theories to explain these differences. This article reviews how these ideas have changed over time as research has produced new information. Currently, the most popular view is that the laryngeal nerve regenerates after injury, albeit incompletely and inconsistently, and that variations in symptoms and laryngeal posture can be accounted for by muscle activity.
Accessory nerve: anatomy and surgical identification
Authors: Lloyd S
Published: September 2007

The XIth cranial nerve or accessory nerve provides the motor supply to the sternocleidomastoid and trapezius muscles. It is frequently encountered during neck surgery, and as such is at risk of iatrogenic injury, resulting in the ‘shoulder syndrome’. Historically, the nerve was sacrificed on oncological grounds during radical neck dissection. However, the basis for sacrifice is unfounded in the majority of cases, and accessory nerve sparing selective neck dissection has equal oncological efficacy. The path of the nerve in the neck is very variable, and there is not a wholly reliable landmark for its identification. However, there are a number of methods described in the literature to guide the surgeon in its identification. This paper provides a systematic review of all the methods available for identification of the accessory nerve, and comments on the reliability of each. In doing so, the detailed anatomy of the accessory nerve is also described.
Frontal mucocele caused by an ectopic maxillary tooth
Authors: Buchanan M A , Prince S E , Prinsley P R
Published: September 2007

Objective:

To present a previously unreported cause of frontal mucocele.

Case report:

A patient presented with a frontal mucocele and maxillary sinusitis. Computed tomography revealed an ectopic maxillary tooth as the cause of her signs and symptoms. Removal of the tooth by a Caldwell–Luc procedure facilitated resolution of the mucocele. Conventional treatment of mucoceles by endoscopic sinus surgery, and other rhinological sequelae of ectopic teeth, are considered.

Conclusion:

This is the first documented case of an ectopic tooth causing a frontal mucocele, and demonstrates how effectively the patient's symptoms resolved on removal of the tooth.
An unusual presentation of oropharyngeal mucosal plasmacytosis related to toothpaste
Authors: Tong D C , Leaper M R , Colquhoun A N , Rich A M
Published: September 2007

Objective:

We present the case of a 59-year-old Chinese patient with an unusual presentation of mucosal plasmacytosis involving the oropharynx, related to the use of toothpaste.

Method:

Case presentation and review of English medical literature involving mucosal plasmacytosis.

Results:

Mucosal plasmacytosis is an uncommon disease process and has been associated with hypersensitivity reactions. Most cases involve the gingival mucosa, although there have been reports of cases involving other oral mucosal sites and the upper aerodigestive tract. Our case provides an example of oropharyngeal plasmacytosis related to toothpaste. A resolution of signs and symptoms followed withdrawal of the suspected allergens.

Conclusion:

Mucosal plasmacytosis is a benign inflammatory process that may appear to be more sinister on clinical examination. Skin patch testing is a useful adjunct in confirming the diagnosis.
DoesLitomosoides sigmodontissynthesize dimethylethanolamine from choline?
Authors: HOUSTON K. M. , BABAYAN S. A. , ALLEN J. E. , HARNETT W.
Published: September 2007

Juvenile femaleLitomosoides sigmodontissecrete a protein (Juv-p120) highly modified with dimethylethanolamine (DMAE). In an attempt to establish the source of this decoration worms were pulsed with [3H]-choline and [3H]-ethanolamine and the radio-isotope labelled products analysed. Both isotope labels were successfully taken up by the worms, as demonstrated by labelling of phospholipids with [3H]-choline, being predominantly incorporated into phosphatidylcholine and [3H]-ethanolamine into phosphatidylethanolamine. Isotope labelling of phosphatidylethanolamine was particularly striking with the worms taking up ~30 times as much labelled ethanolamine as choline. It was possible to detect faint labelling of Juv-p120 with [3H]-ethanolamine after prolonged exposure periods but, unlike the situation with the phospholipids, it was much more readily labelled with [3H]-choline. When pulsing with [3H]-ethanolamine it was also possible to detect isotope-labelled phosphatidylcholine, which may ultimately account for the low levels of labelling of Juv-p120. Overall our results raise the previously unconsidered but intriguing possibility that inL. sigmodontis, choline may be the precursor of DMAE.
Isolation and genotyping ofToxoplasma gondiifrom Ugandan chickens reveals frequent multiple infections
Authors: LINDSTRÖM I. , SUNDAR N. , LINDH J. , KIRONDE F. , KABASA J. D. , KWOK O. C. H. , DUBEY J. P. , SMITH J. E.
Published: September 2007

The genetic make-up of an infectingToxoplasma gondiistrain may be important for the outcome of infection and the risk of reactivation of chronic disease. In order to survey the distribution of different genotypes within an area, free-range chickens act as a good model species. In this study 85 chickens were used to investigate the prevalence, genotype and mouse virulence ofT. gondiiin Kampala, Uganda. Antibodies were detected in 40 chickens, of which 20 had MAT-titres of 1:20 or higher and were also positive by PCR. Genotyping of 5 loci (SAG1, SAG2, SAG3, BTUB and GRA6) showed that 6 strains belonged to genotype I, 8 to Type II and 1 to Type III. Five chickens had multiple infections; 3 individuals with Type I plus Type II and a further 2 harbouring Types I, II and III. Isolates were obtained from 9 chickens via bioassay in mice, 6 were Type II strains and 3 were from animals with mixed infection. This is the first set of AfricanT. gondiistrains to be genotyped at multiple loci and in addition to the 3 predominant lineages we found a small number of new polymorphisms and a high frequency of multiple infections.
Risk factors for physical symptoms after a disaster: a longitudinal study
Authors: van den Berg B. , Grievink L. , van der Velden P. G. , Yzermans C. J. , Stellato R. K. , Lebret E. , Brunekreef B.
Published: September 2007

Background

Although symptoms such as fatigue, headache and pain in bones and muscles are common after disasters, risk factors for these symptoms among disaster survivors have rarely been studied. We examined predisposing, precipitating and perpetuating factors for these physical symptoms among survivors of a man-made disaster. In addition, we examined whether risk factors for physical symptoms differ between survivors and controls.

Method

Survivors completed a questionnaire 3 weeks (n=1567), 18 months and 4 years after the disaster. Symptoms and risk factors were measured using validated questionnaires. A comparison group was included at waves 2 and 3 (n=821). Random coefficient analysis (RCA) was used to study risk factors for symptoms.

Results

Female gender [beta (β)=1.0, 95% confidence interval (CI) 0.6–1.4], immigrant status (β=1.0, 95% CI 0.6–1.4) and pre-disaster psychological problems (β=0.8, 95% CI 0.1–1.4) were predisposing factors for symptoms. Although disaster-related factors were predictors, the relationship between symptoms and disaster-related factors was not very strong and the magnitude of this association was reduced when perpetuating factors were added. Intrusions and avoidance, depression, anxiety and sleeping problems were important perpetuating factors for physical symptoms among survivors and mediated the association between traumatic stress and physical symptoms. Risk factors for symptoms were comparable between survivors and controls.

Conclusions

The results indicate that health-care workers should be alert for physical symptoms among female survivors, immigrant survivors and individuals with a high level of psychological problems both before and after a disaster.
The role of internalizing and externalizing liability factors in accounting for gender differences in the prevalence of common psychopathological syndromes
Authors: Kramer Mark D. , Krueger Robert F. , Hicks Brian M.
Published: September 2007

Background

We hypothesized that gender differences in average levels on the internalizing and externalizing factors that account for co-morbidity among common psychopathological syndromes in both men and women account for gender differences in the prevalence of specific syndromes.

Method

The latent structure of 11 syndromes was examined in a middle-aged (mean age=52.66 years, s.d.=5.82) sample of 2992 (37% men) members of the community-based Minnesota Twin Registry (MTR) assessed using 10 scales of the Psychiatric Diagnostic Screening Questionnaire (PDSQ) and an adult antisocial behavior scale. Confirmatory factorial invariance models were applied to a best-fitting, internalizing–externalizing model.

Results

A ‘strong gender invariance model’ fit best, indicating that gender differences in the means of individual syndromes were well accounted for by gender differences in mean levels of internalizing and externalizing. Women exhibited higher mean levels of internalizing (d=0.23) and lower mean levels of externalizing (d=−0.52) than men.

Conclusions

These findings suggest that risk factors for common mental disorders exhibiting gender differences may influence prevalence at the latent factor level. Future research may benefit from focusing on both the latent factor and individual syndrome levels in explaining gender differences in psychopathology.
Risk factors for chronic fatigue syndrome/myalgic encephalomyelitis: a systematic scoping review of multiple predictor studies
Authors: Hempel S. , Chambers D. , Bagnall A.-M. , Forbes C.
Published: September 2007

Background

The aetiology of chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is still unknown. The identification of risk factors for CFS/ME is of great importance to practitioners.

Method

A systematic scoping review was conducted to locate studies that analysed risk factors for CFS/ME using multiple predictors. We searched for published and unpublished literature in 11 electronic databases, reference lists of retrieved articles and guideline stakeholder submissions in conjunction with the development of a forthcoming national UK guideline. Risk factors and findings were extracted in a concise tabular overview and studies synthesized narratively.

Results

Eleven studies were identified that met inclusion criteria: two case-control studies, four cohort studies, three studies combining a cohort with a case-control study design, one case-control and twin study and one cross-sectional survey. The studies looked at a variety of demographic, medical, psychological, social and environmental factors to predict the development of CFS/ME. The existing body of evidence is characterized by factors that were analysed in several studies but without replication of a significant association in more than two studies, and by studies demonstrating significant associations of specific factors that were not assessed in other studies. None of the identified factors appear suitable for the timely identification of patients at risk of developing CFS/ME within clinical practice.

Conclusions

Various potential risk factors for the development of CFS/ME have been assessed but definitive evidence that appears meaningful for clinicians is lacking.
Emergence of increasing linezolid-resistance in enterococci in a post-outbreak situation with vancomycin-resistantEnterococcus faecium
Authors: SCHULTE B. , HEININGER A. , AUTENRIETH I. B. , WOLZ C.
Published: September 2007

During 2004 and at the start of 2005 a university hospital in Southwest Germany was affected by an extensive outbreak of vancomycin-resistantEnterococcus faecium(VRE). Although the outbreak was contained, linezolid-resistant enterococci emerged during and after the outbreak as the usage of linezolid became more common. Linezolid resistance was no longer limited to VRE. Nosocomial spread of linezolid-resistant but vancomycin-susceptibleE. faeciumwas detected and these strains also emerged in patients without prior drug exposure. Linezolid should therefore be used with caution and the susceptibility of isolates monitored over time. Isolation precautions and screening of contacts should be considered to avoid spread of resistant isolates.
Epidemiological and virological characterization of a large community-wide outbreak of hepatitis A in southern Italy
Authors: PONTRELLI G. , BOCCIA D. , DI RENZI M. , MASSARI M. , GIUGLIANO F. , CELENTANO L. PASTORE , TAFFON S. , GENOVESE D. , DI PASQUALE S. , SCALISE F. , RAPICETTA M. , CROCI L. , SALMASO S.
Published: September 2007

A large outbreak of hepatitis A virus (HAV) infection occurred in 2004 in Campania, a region of southern Italy, with 882 cases reported between 1 January and 1 August. The local public health authorities and the Italian National Institute of Health carried out investigations in order to characterize the agent, identify the source of infection and the route of transmission, and implement appropriate control measures. A web-based reporting system enhanced the flow of information between public health authorities, providing real-time epidemic curves and frequency distributions. The same 1B HAV genotype was found in 90% of sera from a subset of patients with acute disease, suggesting a local common source. A case-control study in the municipality with the highest attack rate showed that raw seafood consumption, in particular if illegally sold in water, was strongly associated with HAV illness. Samples of seafood systematically collected from retailers were found contaminated by HAV.
HTLV-1 infection is associated with a history of active tuberculosis among family members of HTLV-1-infected patients in Peru
Authors: VERDONCK K. , GONZÁLEZ E. , SCHROOTEN W. , VANHAM G. , GOTUZZO E.
Published: September 2007

The purpose of this study was to assess the association between human T-lymphotropic virus 1 (HTLV-1) and a lifetime history of active tuberculosis (TB) among relatives of HTLV-1-infected patients. We reviewed clinical charts of all relatives of HTLV-1-infected index cases who attended our institute in Lima from 1990–2004. The data of 1233 relatives was analysed; 394 (32·0%) were HTLV-1 positive. Eighty-one subjects (6·6%) had a history of active TB, including 45/394 (11·4%) HTLV-1-positive and 36/839 (4·3%) HTLV-1-negative relatives (P<0·001). On multivariate analysis, three factors were associated with TB history: HTLV-1 infection (adjusted OR 2·5, 95% CI 1·6–3·9), age (adjusted OR 1·3, 95% CI 1·1–1·5 per 10-year age increase) and relation to the index case (adjusted OR 2·6, 95% CI 1·3–5·1, for siblingsvs. spouses of index cases). In conclusion, HTLV-1 infection may increase the susceptibility to active TB. In populations where both infections are frequent, such an association could affect the dynamics of TB.
Gewalt an Schulen am Beispiel von Bullying
Authors: Scheithauer Herbert , Hayer Tobias , Bull Heike Dele
Published: September 2007

Zusammenfassung. Bullying stellt eine Form von Gewalt dar, die zum Schulalltag vieler Schülerinnen und Schüler gehört und sowohl körperliche und verbale Gewalt, aber auch Hänseleien oder Viktimisierung durch systematische Ausgrenzung einzelner Schülerinnen bzw. Schüler umfasst. Bullying tritt zumeist im sozialen Kontext “Schule” stabil auf und geht mit einer Vielzahl negativer Folgen einher. “Neue Medien” können dabei andauernde Viktimisierungen in Form von Cyberbullying unterstützen. In der Bullyingforschung wird zumeist lediglich die Täter- und/oder Opferperspektive betrachtet. Bullying tritt jedoch häufig in Anwesenheit von weiteren Beteiligten auf und kann als gruppendynamisches Phänomen betrachtet werden (Participant Role Approach). Zur kontroversen Diskussion führte die These der sozial intelligenten Täterin bzw. des Täters, der sein viktimisierendes Verhalten zielorientiert und im “machiavellistischen Sinne” sozial manipulativ zur Erreichung seiner Ziele einsetzt. Aus den dargestellten Befunden werden Implikationen für wirksame Präventionsansätze und Interventionen im schulischen Kontext abgeleitet.
Subjektive Vorstellungen über ältere Menschen und das Altern
Authors: Wehr Thomas , Buchwald Florian
Published: September 2007

Zusammenfassung. In den beiden vorliegenden Normierungsstudien wurden 218 Personeneigenschaften in Bezug auf das Altersstereotyp (“alter Mensch/Rentner”) sowie auf normative Vorstellungen über das Altern (Erwünschtheit, Kontrollierbarkeit, Entwicklungsperiode) von insgesamt 501 studentischen Versuchspersonen beurteilt. Normierung 1 ermöglichte eine Kategorisierung der Wörter in drei Merkmal-Sets mit jeweils 30 typischen Eigenschaften (stereotyp-konsistent, stereotyp-inkonsistent und stereotyp-neutral). Normierung 2 ergänzte die Merkmal-Sets um die Analyse normativer Vorstellungen über das Altern. Demnach korrespondierten alters-konsistente Eigenschaften mit einer reduzierten, wenn auch moderaten Erwünschtheit und Kontrollierbarkeit. Zudem unterschieden sich die wahrgenommenen Anfangs- und Endpunkte der Entwicklungsperioden der Merkmal-Sets deutlich. Schließlich kann nach Vergleichen mit äquivalenten Normen von Heckhausen, Dixon und Baltes (1989) zeitliche Stabilität normativer Vorstellungen über die Entwicklung alters-konsistenter Eigenschaften bei jungen Erwachsenen vermutet werden.
Levoglucosan levels at background sites in Europe for assessing the impact of biomass combustion on the European aerosol background
Authors: Puxbaum Hans , Caseiro Alexandre , Sánchez‐Ochoa Asunción , Kasper‐Giebl Anne , Claeys Magda , Gelencsér András , Legrand Michel , Preunkert Susanne , Pio Casimiro
Published: September 2007

Atmospheric levoglucosan has been determined as a proxy for “biomass smoke” in samples from six background stations on a west–east transect extending from the Atlantic (Azores) to the mid‐European background site KPZ (K‐Puszta, Hungary). Concentration levels of levoglucosan (biannual averages) in the west–east transect range from 0.005μg/m3at the oceanic background site AZO (Azores) to 0.52μg/m3at AVE (Aveiro, Portugal). The atmospheric concentration of “biomass smoke” (biannual averages) was derived from the levoglucosan data with wood‐type‐specific conversion factors. Annual averages of wood smoke levels ranged from 0.05μg/m3at AZO to 4.3μg/m3at AVE. Winter (DJF) averages at the low‐level sites AVE and KPZ were 10.8 and 6.7μg/m3, respectively. Relative contributions of biomass smoke to organic matter (OM) range from around 9–11% at the elevated sites SIL, PDD and SBO, as well as for AZO, to 36% at the low‐level site AVE and 28% at KPZ. Surprisingly high relative concentrations of biomass smoke in OM (68 and 47%) were observed for wintry conditions at the continental low‐level CARBOSOL sites AVE and KPZ. Thus biomass smoke is a very important constituent of the organic material in the mid and west European background with summer contributions to organic matter of around 1–6% and winter levels of around 20% at the elevated mountain sites and 47–68% at rural flat terrain sites, not including secondary organic aerosol from biomass combustion sources.
The tropical forest and fire emissions experiment: Trace gases emitted by smoldering logs and dung from deforestation and pasture fires in Brazil
Authors: Christian Ted J. , Yokelson Robert J. , Carvalho João A. , Griffith David W. T. , Alvarado Ernesto C. , Santos José C. , Neto Turibio Gomes Soares , Veras Carlos A. Gurgel , Hao Wei Min
Published: September 2007

Earlier work showed that Amazonian biomass burning produces both lofted and initially unlofted emissions in large amounts. A mobile, Fourier transform infrared spectrometer (FTIR) measured the unlofted emissions of 17 trace gases from residual smoldering combustion (RSC) of logs as part of the Tropical Forest and Fire Emissions Experiment (TROFFEE) during the 2004 Amazonian dry season. The RSC emissions were highly variable and the few earlier RSC measurements lay near the high end of combustion efficiency observed in this study. Fuel consumption by RSC was ∼5% of total for a planned deforestation fire. Much regional RSC probably occurs in the residual woody debris burned during pasture maintenance fires. RSC could increase estimated total fire emissions for the Amazon region by 20–50% for several important VOC. FTIR emissions measurements of burning dung (in a pasture) showed high emission ratios for acetic acid and ammonia to CO (6.6 ± 3.4% and 8.9 ± 2.1%). Large emissions of nitrogen containing trace gases from burning dung and crop waste could mean that biomass burning in India produces more particle mass than previously assumed. Measurements of late‐stage kiln emissions suggested that VOC/CO may increase as carbonization is extended. A cook stove emitted many VOC and NH3 far outside the range observed for open wood cooking fires. Enclosed/vented cooking stoves may change the chemistry of the smoke that is emitted.
Satellite‐derived aerosol optical depth over dark water from MISR and MODIS: Comparisons with AERONET and implications for climatological studies
Authors: Kahn Ralph A. , Garay Michael J. , Nelson David L. , Yau Kevin K. , Bull Michael A. , Gaitley Barbara J. , Martonchik John V. , Levy Robert C.
Published: September 2007

Although the current Multiangle Imaging Spectroradiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite passive remote sensing midvisible aerosol optical thickness (AOT) products are accurate overall to about 0.05 or 20%, they differ systematically on a global, monthly average basis, by about 0.03 to 0.05. Some key climate change and other applications require accuracies of 0.03 or better. The instruments are sufficiently stable and well characterized, and have adequate signal‐to‐noise, to realize such precision. However, assumptions made in the current standard aerosol retrieval algorithms produce AOT biases that must be addressed first. We identify the causes of AOT discrepancies over dark water under typical, relatively low AOT conditions and quantify their magnitudes on the basis of detailed analysis. Examples were selected to highlight key issues for which there are coincident MISR, MODIS, and Aerosol Robotic Network (AERONET) observations. Instrument calibration and sampling differences, assumptions made in the MISR and MODIS standard algorithms about ocean surface boundary conditions, missing particle property or mixture options, and the way reflectances used in the retrievals are selected each contribute significantly to the observed differences under some circumstances. Cloud screening is also identified as a factor, though not fully examined here, as are the relatively rare high‐AOT cases over ocean. Specific algorithm upgrades and further studies indicated by these findings are discussed, along with recommendations for effectively using the currently available products for regional and global applications.
Spatial heterogeneity in photosynthesis‐irradiance parameters of phytoplankton across a cyclonic eddy in the Antarctic Divergence zone along 140°E
Authors: Yoshikawa Takashi , Miki Meguru , Takeda Shigenobu , Furuya Ken
Published: September 2007

The latitudinal variation in the photosynthesis‐irradiance (P‐E) relationship of phytoplankton was investigated across a cyclonic eddy in the Antarctic Divergence zone along the 140°E longitude. Both the maximum photosynthetic rate (P*max) and maximum light utilization coefficient (α*) were lower at stations within the eddy as compared with those in the continental shelf‐slope area and the offshore area. The low‐density water mass of the eddy prevented the upward and horizontal supply of macronutrients and micronutrients, which likely resulted in a reduction of P*max and α*. In contrast, both P*max and α* were large and variable in the slope area, probably owing to a local stability resulting from the less‐saline surface water. The present study indicates the possibility that longitudinal variations in the latitudinal pattern of meanders, eddies, seasonal sea‐ice extent, and topographical conditions significantly influence the mesoscale variations in the P‐E parameters and primary production in the Southern Ocean.
Effect of ice sheet interactions in anthropogenic climate change simulations
Authors: Mikolajewicz Uwe , Vizcaíno Miren , Jungclaus Johann , Schurgers Guy
Published: September 2007

We investigate the effect of ice sheets on climate change under elevated atmospheric CO2 concentrations with an atmosphere ocean general circulation model (AOGCM) coupled to a thermomechanical ice sheet model and a vegetation model. The effect of increased meltwater fluxes from ice sheets turned out to be negligible in the phase of initial weakening of the North Atlantic meridional overturning circulation (AMOC), and more important during the recovery in subsequent centuries. Lower surface height of the Greenland ice sheet (GRIS) leads locally to a warming, especially in winter, and remotely to a cooling over northern Eurasia due to modified atmospheric circulation. With quadrupling of the atmospheric CO2 concentration the entire GRIS is exposed to surface melt in summer. On formerly ice‐covered grid points climate locally warms strongly via increased albedos, with positive feedbacks due to boreal forest expansion.
Observations of fine‐scale transport structure in the upper troposphere from the High‐performance Instrumented Airborne Platform for Environmental Research
Authors: Bowman Kenneth P. , Pan Laura L. , Campos Teresa , Gao Rushan
Published: September 2007

The Progressive Science Mission in December 2005 was the first research use of the new NCAR High‐performance Instrumented Airborne Platform for Environmental Research (HIAPER) aircraft. The Stratosphere‐Troposphere Analyses of Regional Transport (START) component of the mission was designed to investigate the dynamical and chemical structure of the upper troposphere and lower stratosphere. Flight 5 of the Progressive Science mission was a START flight that sampled near the tropopause in an area between the main jet stream and a large, quasi‐stationary, cutoff low. The large‐scale flow in this region was characterized by a hyperbolic (saddle) point. In this study the in situ measurements by HIAPER are combined with flow analyses and satellite data to investigate the quasi‐isentropic stirring of trace species in the upper troposphere. As expected from theoretical considerations, strong stretching and folding deformation of the flow near the hyperbolic point resulted in rapid filamentation of air masses and sharp gradients of constituents. Calculations of the stirring using operational meteorological analyses from the NCEP Global Forecast System model produced excellent agreement with HIAPER and satellite observations of trace species. Back trajectories indicate that elevated ozone levels in some filaments likely came from a large stratospheric intrusion that occurred upstream in the jet over the north Pacific Ocean. The methods presented here can be used with operational forecasts for future flight planning.
Anomalous transport in molecularly confined spaces
Authors: Bhatia S. K. , Nicholson D.
Published: September 2007

We develop a novel theory to predict the density dependence of the diffusivity of simple fluids in a molecularly sized nanopore with diffusely reflecting walls, incorporating nearest neighbor intermolecular interactions within the framework of the recent oscillator model of low density transport arising from this laboratory. It is shown that when the pore width is about two molecular diameters, at sufficiently high densities these interactions lead to a repulsive inner core, as a result of which the diffusing molecules undergo more frequent reflections at the wall. This leads to a reduction in diffusivity with increase in density, which is consistent with molecular dynamics simulation results, and contrasts with the behavior in larger pores where the transport coefficient has previously been shown to increase with increase in density due to viscouslike intermolecular interactions. At low densities the behavior is opposite, with the inner core becoming more attractive with increase in density, which can lead to an increase in diffusivity. The theory consistently explains molecular dynamics simulation results when the inhomogeneous pair distribution function of moving particles in the pore is axially periodic, suggesting concerted motion of neighboring molecules. It is also shown that a potential of mean force concept is inadequate for describing the influence of intermolecular interactions on transport.
Synchronization of a class of coupled chaotic delayed systems with parameter mismatch
Authors: Huang Tingwen , Li Chuandong , Liao Xiaofeng
Published: September 2007

In this paper, we study the effect of parameter mismatch on the synchronization of a class of coupled chaotic systems with time delays. In the presence of parameter mismatch, the delayed coupled chaotic systems are investigated in terms of the quasisynchronization. A simple and yet easily applicable criterion for quasisynchronization of a large class of coupled chaotic systems with delays is derived based on the Lyapunov stability theory. As an example, the Ikeda oscillator is simulated, thereby validating the theoretical result in this paper.
Influence of chemical pressure effects on nonlinear thermal conductivity of intrinsically granular superconductors
Authors: Sergeenkov Sergei
Published: September 2007

Using a two-dimensional model of capacitively coupled Josephson junction arrays (created by a network of twin boundary dislocations with strain fields acting as an insulating barrier between hole-rich domains in underdoped crystals), we study the influence of chemical pressure (∇μ) on nonlinear (i.e., ∇T dependent) thermal conductivity (NLTC) of an intrinsically granular superconductor. Quite a substantial enhancement of NLTC is predicted when intrinsic chemoelectric field Eμ∝∇μ closely matches the externally produced thermoelectric field ET∝∇T. The estimates of the model parameters suggest a realistic possibility to experimentally monitor this effect in nonstoichiometric high-TC superconductors.
Spectroscopic study of dielectric barrier discharges in cellular polypropylene ferroelectrets
Authors: Qiu Xunlin , Mellinger Axel , Wirges Werner , Gerhard Reimund
Published: September 2007

The transient light emission from the dielectric barrier discharges (DBDs) in cellular polypropylene ferroelectrets subjected to high electric poling fields was spectroscopically measured. The spectrum shows strong emission from the second positive system of molecular nitrogen, N2(CΠu3)→N2(BΠg3), and the first negative system of N2+, N2+(BΣu+2)→N2+(XΣg+2), consistent with a DBD in air. When a dc voltage is applied stepwise to the ferroelectret film, light emission starts above a threshold, coinciding with the threshold voltage in obtaining piezoelectricity. From selected vibronic band strength ratios, the electric field in the discharge was determined and found to agree with Townsend breakdown.
Strip injection for carbon ion synchrotrons
Authors: Lee S. Y. , Tam W. M. , Liu Z.
Published: September 2007

Requirements and effects of strip injection of C4+ at 6MeV∕u into carbon ion synchrotrons are studied. The setup is composed of three chicane dipoles, one Lambertson septum, and one carbon stripping foil at a thickness of 60μg∕cm2. The required length of the injection section is about 4.1m. The emittance growth due to multiple Coulomb scatterings is studied.
Printed shadow masks for organic transistors
Authors: Noguchi Yoshiaki , Sekitani Tsuyoshi , Someya Takao
Published: September 2007

We have manufactured organic field-effect transistors by using shadow masks that are patterned by a screen printing system. The 50-nm-thick pentacene layer is sublimed as a channel in the vacuum system through the shadow mask on the base film with a multilayer patterned by ink-jet. After the deposition of the pentacene layer, the shadow mask is peeled off from the base film without any mechanical damages to the lower structures. The mobility in the saturation regime is 0.4cm2∕Vs and the on-off ratio exceeds 105.
Temperature effects of Si interface passivation layer deposition on high-k III-V metal-oxide-semiconductor characteristics
Authors: Ok InJo , Kim H. , Zhang M. , Zhu F. , Park S. , Yum J. , Zhao H. , Lee Jack C.
Published: September 2007

In this work, we studied the electrical characteristics of TaN∕HfO2∕GaAs metal-oxide-semiconductor capacitors with Si interface passivation layer (IPL) under various postdeposition anneal (PDA) conditions and various Si deposition temperatures/times. Using optimal Si IPL under reasonable PDA, post metal anneal conditions, and various Si deposition temperatures, excellent electrical characteristics with low frequency dispersion (<5%, and 50mV) and reasonable Dit value (∼1012eV−1cm−2) can be obtained. It was found that higher temperature of Si IPL deposition and longer PDA time at 600°C improved equivalent oxide thickness and leakage current.
DNA sequence- and conformation-directed positioning of nucleosomes by chromatin-remodeling complexes
Authors: Rippe Karsten , Schrader Anna , Riede Philipp , Strohner Ralf , Lehmann Elisabeth , Längst Gernot
Published: September 2007

Chromatin-remodeling complexes can translocate nucleosomes along the DNA in an ATP-coupled reaction. This process is an important regulator of all DNA-dependent processes because it determines whether certain DNA sequences are found in regions between nucleosomes with increased accessibility for other factors or wrapped around the histone octamer complex. In a comparison of seven different chromatin-remodeling machines (ACF, ISWI, Snf2H, Chd1, Mi-2, Brg1, and NURF), it is demonstrated that these complexes can read out DNA sequence features to establish specific nucleosome-positioning patterns. For one of the remodelers, ACF, we identified a 40-bp DNA sequence element that directs nucleosome positioning. Furthermore, we show that nucleosome positioning by the remodelers ACF and Chd1 is determined by a reduced affinity to the end product of the translocation reaction. The results suggest that the linkage of differential remodeling activities with the intrinsic binding preferences of nucleosomes can result in establishing distinct chromatin structures that depend on the DNA sequence and define the DNA accessibility for other protein factors.
Physical plasticity of the nucleus in stem cell differentiation
Authors: Pajerowski J. David , Dahl Kris Noel , Zhong Franklin L. , Sammak Paul J. , Discher Dennis E.
Published: September 2007

Cell differentiation in embryogenesis involves extensive changes in gene expression structural reorganization within the nucleus, including chromatin condensation and nucleoprotein immobilization. We hypothesized that nuclei in naive stem cells would therefore prove to be physically plastic and also more pliable than nuclei in differentiated cells. Micromanipulation methods indeed show that nuclei in human embryonic stem cells are highly deformable and stiffen 6-fold through terminal differentiation, and that nuclei in human adult stem cells possess an intermediate stiffness and deform irreversibly. Because the nucleo-skeletal component Lamin A/C is not expressed in either type of stem cell, we knocked down Lamin A/C in human epithelial cells and measured a deformability similar to that of adult hematopoietic stem cells. Rheologically, lamin-deficient states prove to be the most fluid-like, especially within the first ≈10 sec of deformation. Nuclear distortions that persist longer than this are irreversible, and fluorescence-imaged microdeformation with photobleaching confirms that chromatin indeed flows, distends, and reorganizes while the lamina stretches. The rheological character of the nucleus is thus set largely by nucleoplasm/chromatin, whereas the extent of deformation is modulated by the lamina.
Structure, dynamics, and evolution of centromeric nucleosomes
Authors: Dalal Yamini , Furuyama Takehito , Vermaak Danielle , Henikoff Steven
Published: September 2007

Centromeres are defining features of eukaryotic chromosomes, providing sites of attachment for segregation during mitosis and meiosis. The fundamental unit of centromere structure is the centromeric nucleosome, which differs from the conventional nucleosome by the presence of a centromere-specific histone variant (CenH3) in place of canonical H3. We have shown that the CenH3 nucleosome core found in interphase
Drosophila
cells is a heterotypic tetramer, a “hemisome” consisting of one molecule each of CenH3, H4, H2A, and H2B, rather than the octamer of canonical histones that is found in bulk nucleosomes. The surprising discovery of hemisomes at centromeres calls for a reevaluation of evidence that has long been interpreted in terms of a more conventional nucleosome. We describe how the hemisome structure of centromeric nucleosomes can account for enigmatic properties of centromeres, including kinetochore accessibility, epigenetic inheritance, rapid turnover of misincorporated CenH3, and transcriptional quiescence of pericentric heterochromatin. Structural differences mediated by loop 1 are proposed to account for the formation of stable tetramers containing CenH3 rather than stable octamers containing H3. Asymmetric CenH3 hemisomes might interrupt the global condensation of octameric H3 arrays and present an asymmetric surface for kinetochore formation. We suggest that this simple mechanism for differentiation between centromeric and packaging nucleosomes evolved from an archaea-like ancestor at the dawn of eukaryotic evolution.
Lactose intolerance and long‐standing pelvic pain after pregnancy: a case control study
Authors: GRANATH AINA , HELLGREN MARGARETA , GUNNARSSON RONNY
Published: September 2007

Background. Long‐standing pelvic pain during pregnancy and after delivery (PPP) is common. Its causes are not fully understood. A scientifically, undocumented, clinical observation is PPP patients often reporting unspecific abdominal pain and adverse reactions to milk. The main objective in this pilot study was to investigate if lactose intolerance, celiac disease or allergic propensity are risk factors for developing pelvic pain after delivery. Methods. A matched, case control study, where consecutive patients consulting a registered physiotherapist specialised in treating women with postpartum pelvic pain were compared to matched controls. Results. Lactose intolerance was found in 10 of 15 patients, and in 3 of 15 matched, healthy controls (p = 0.05). No difference was seen between groups in the prevalence of celiac disease or allergic propensity. Conclusion. This study suggests that lactose intolerance might be a possible risk factor for pelvic pain after delivery.
Low predictive value of traditional risk factors in identifying women at risk for gestational diabetes
Authors: OGONOWSKI JAROSŁAW , MIAZGOWSKI TOMASZ , HOMA KATARZYNA , CELEWICZ ZBIGNIEW , KUCZYŃSKA MAGDALENA
Published: September 2007

Background. There is no worldwide agreement on the best way to screen for gestational diabetes mellitus (GDM), and different diagnostic methods have been developed in order to identify women at risk. The aim of this study was to evaluate the prevalence and predictive value of the traditional risk indicators for GDM in a large group of Caucasian women. Methods. We evaluated the frequency distribution of age, body mass index (BMI), prior macrosomia, prior GDM, and family history of diabetes of 1,414 pregnant women with GDM and 1,011 healthy pregnant women. Results. The distribution of risk factors in both groups was different and significantly higher in GDM women. The cut‐off value for age was 28years, and 23kg/m2 for BMI. The accumulation of two or more risk factors was frequent in GDM, but not in healthy women. By multiple logistic regression, there were significant interactions between independent variables of interest and GDM (OR: 3.19; p<0.001; sensitivity: 57.9%, specificity: 69.8%). The strongest predictors were prior GDM (OR: 4.35; 95% CI: 2.42–7.82) and a family history of diabetes (OR: 3.03; 95% CI: 2.47–3.72); less predictive were age (OR: 1.69; 95% CI: 1.44–1.99), BMI (OR: 1.50; 95% CI: 1.28–1.77), and prior macrosomia (OR: 1.64; 95% CI: 1.19–2.26). Conclusions. Selective screening based on traditional risk factors for GDM had relatively low sensitivity, and identified <60% of Caucasian women at risk. The cut‐off value for BMI as a risk indicator (23kg/m2) was lower than that proposed by guidelines about screening for GDM.
Endogenous antioxidant defences in plasma and erythrocytes of pregnant women during different trimesters of pregnancy
Authors: ADEMUYIWA OLADIPO , ODUSOGA OKANLAWON L. , ADEBAWO OLUGBENGA O. , UGBAJA REGINA N.
Published: September 2007

Background. To assess the antioxidant capacity of pregnant women in Ogun State, Nigeria. Methods. The activities of total superoxide dismutase (total SOD), manganese superoxide dismutase (Mn‐SOD), catalase (CAT), glutathione transferase (GST), aminolevulinic acid dehydratase (ALAD), and the concentrations of glutathione (GSH), were determined in the plasma and red blood cells of non‐pregnant (n = 20), normal healthy pregnant women during different trimesters of pregnancy (n = 90), and pregnant women with pre‐eclampsia (n = 7). Results. A 2‐fold increase in erythrocyte CAT activity was observed in the pregnant women (p<0.05), while CAT activity in the pre‐eclamptic women was not significantly different from control (p>0.05). A 3‐fold increase in plasma Mn‐SOD was observed in the pregnant women including those with pre‐eclampsia (p<0.05). ALAD activities in the first, second and third trimesters of pregnancy were 35, 51 and 55% of control, respectively (p<0.05), while in the women with pre‐eclampsia it was 31% of control (p<0.05). Total SOD also decreased significantly in the erythrocytes of the pre‐eclamptic women (p<0.05). Other antioxidants (GST and GSH) were not affected. Conclusions. Results suggest that oxidative stress is higher in pregnancy than in non‐pregnant state. Our findings also suggest that while plasma Mn‐SOD might play a significant role in detoxifying the superoxide anions produced in the placenta, the decomposition of hydrogen peroxide in erythrocytes is mainly due to CAT activity. Whether inhibition of ALAD contributes to the etiology of pre‐eclampsia remains to be elucidated.