bluuebunny/crossref_metadata_2025 huggingface dataset:
Variations of ethnic boundary significance in north Norway
Authors: Thuen Trond
Published: May 2012

In coastal north Norway the Saami people have lived in a close relationship with Norwegians or Norse people for a thousand years or more. This relationship has been articulated in various ways over the centuries, and this article argues that in parts of the region it took a rather intimate form based on the shared exploitation of the dominant marine and terrestrial niches, a common class position as tenant farmers, a varying practice of inter-ethnic marital relations and the effects of a bilateral kinship system. Various forms of inter-ethnic contact and exchange may thus have served to reduce the relevance of ethnic difference in daily life, as suggested by Barth's argument about the integrative effect of transactions, but contrary to his argument about the transactional reinforcement of ethnic boundaries. Contrary to the intention, governmental assimilatory efforts served to reproduce the boundary as the basis for a ranked society and left coastal Saami individuals in some confusion as to how to define themselves, often opting for a mixed category of Norwegian and Saami, labelled ‘Northerner’. Ethno-political emancipation in recent years has tended to put pressure on this identity construction and promoted a dichotomised identity as either Saami or Norwegian.
Inefficient cerebral recruitment as a vulnerability marker for schizophrenia
Authors: Liddle E. B. , Bates A. T. , Das D. , White T. P. , Groom M. J. , Jansen M. , Jackson G. M. , Hollis C. , Liddle P. F.
Published: May 2012

Background

Patients with schizophrenia and their first-degree relatives exhibit both abnormally diminished and increased neural activation during cognitive tasks. In particular, excessive task-related activity is often observed when tasks are easy, suggesting that inefficient cerebral recruitment may be a marker of vulnerability for schizophrenia. This hypothesis might best be tested using a very easy task, thus avoiding confounding by individual differences in task difficulty.

Method

Eighteen people with schizophrenia, 18 unaffected full siblings of patients with schizophrenia and 26 healthy controls performed an easy auditory target-detection task in a 3-T magnetic resonance imaging (MRI) scanner. Groups were matched for accuracy on the task. Blood oxygen level-dependent (BOLD) responses to non-target stimuli in participants with vulnerability for schizophrenia (siblings and patients) were compared with those of healthy controls, and those of patients with those of unaffected siblings. BOLD responses to targets were compared with baseline, across groups.

Results

Subjects with vulnerability for schizophrenia showed significant hyperactivation to non-targets in brain areas activated by targets in all groups, in addition to reduced deactivation to non-targets in areas suppressed by targets in all groups. Siblings showed greater activation than patients to non-targets in the medial frontal cortex. Patients exhibited significantly longer reaction times (RTs) than unaffected siblings and healthy controls.

Conclusions

Inefficient cerebral recruitment is a vulnerability marker for schizophrenia, marked by reduced suppression of brain areas normally deactivated in response to task stimuli, and increased activation of areas normally activated in response to task stimuli. Moreover, siblings show additional activation in the medial frontal cortex that may be protective.
Social capital affects the health of older people more strongly than that of younger people
Authors: MUCKENHUBER JOHANNA , STRONEGGER WILLIBALD J. , FREIDL WOLFGANG
Published: May 2012

The study examines whether social capital affects health of older people more strongly than it affects health of younger individuals. Following Pierre Bourdieu's concept, social capital has been analysed on a cognitive dimension, distinguishing between institutional and informal social capital. The analysis is based on the data of the Austrian Health Interview Survey 2006–07 with a representative sample of 15,575 people. Multivariate linear regression models were calculated. Measures of health and social capital were operationalised by indices based on the quality of life inventory of the World Health Organization, the WHOQOL-Brief questionnaire. The analysis has shown institutional social capital to be significantly more important for health of older people (60 years or older) than for younger people. There is a gender difference in the interaction between informal social capital and age in their association with psychological health. In contrast to the sub-sample of women, the psychological health of older men is more strongly affected by a lack of informal social capital than that of younger men. Institutional social capital is of special importance for the health of older people. Therefore health-promotion activities for older people should include activities to strengthen their social capital.
AGE OF ONSET AND NATIVELIKE L2 ULTIMATE ATTAINMENT OF MORPHOSYNTACTIC AND PHONETIC INTUITION
Authors: Abrahamsson Niclas
Published: May 2012

Research has consistently shown there is a negative correlation between age of onset (AO) of acquisition and ultimate attainment (UA) of either pronunciation or grammar in a second language (L2). A few studies have indeed reported nativelike behavior in some postpuberty learners with respect to either phonetics/phonology or morphosyntax, a result that has sometimes been taken as evidence against the critical period hypothesis (CPH). However, in the few studies that have employed a wide range of linguistic tests and tasks, adult learners have not exhibited nativelike L2 proficiency across the board of measures, which, according to some, suggests that the hypothesis still holds. The present study investigated the relationship between AO and UA and the incidence of nativelikeness when measures of phonetic and grammatical intuition are combined. An additional aim was to investigate whether children and adults develop the L2 through fundamentally different brain mechanisms—namely, whether children acquire the language (more) implicitly as an interdependent whole, whereas adults learn it (more) explicitly as independent parts of a whole.
Social contact patterns and leprosy disease: a case-control study in Bangladesh
Authors: FEENSTRA S. G. , NAHAR Q. , PAHAN D. , OSKAM L. , RICHARDUS J. H.
Published: May 2012

Socioeconomic and culturally defined social contact patterns are expected to be an important determinant in the continuing transmission ofMycobacterium lepraein leprosy-endemic areas. In a case-control study in two districts in Bangladesh, we assessed the association between social contact patterns and the risk of acquiring clinical leprosy. Social contacts of 90 recently diagnosed patients were compared to those of 199 controls. Leprosy was associated with a more intensive social contact pattern in the home [odds ratio (OR) 1·09, 95% confidence interval (CI) 1·00–1·19,P = 0·043] and in the nearby neighbourhood (OR 1·07, 95% CI 1·03–1·11,P = 0·001). Although it is known thatM. lepraespreads most easily within households of infected persons, in endemic areas social contacts within the neighbourhood, village or urban ward, also appear to be important for transmission. We advise that disease control measures in leprosy-endemic areas should not be limited to households, but include high-risk groups in the nearby neighbourhood of patients.
Definitive specimens of Merlucciidae (Gadiformes) from the Eocene James Ross Basin of Isla Marambio (Seymour Island), Antarctic Peninsula
Authors: Claeson Kerin M. , Eastman Joseph T. , Macphee Ross D. E.
Published: May 2012

An isolated partial right dentary (BAS D.515.2) collected by the British Antarctic Survey prompted a re-evaluation of gadiform remains from the La Meseta Formation (conventionally middle Eocene) of Isla Marambio (Seymour Island), Antarctic Peninsula. Modern gadiforms (hakes and cods) range from the Arctic to Antarctic, inhabiting deep sea benthic, shore, estuarine, and freshwater environments. Based on a fossil record primarily composed of otoliths, they are known to extend back to the Eocene and Oligocene. The new specimen was recovered from the fossil penguin locality D.515. It is characterized by a single row of sharp, ankylosed teeth set upon robust bony pedestals. The surface anterior to the mental foramen exhibits ascending and descending ridges with slightly rugose texture. The ascending ridge is fractured, but partially covers the lateral aspect of the tooth row. BAS D.515.2 is unlike the dentary of macrourid gadiforms, also recovered from the Eocene of Antarctica. BAS D.515.2 preserves several features similar to previously published accounts of the gadiform “†Mesetaichthys” from Isla Marambio. These specimens are probably the same taxon and their combined character suite indicates it is a member of Merluccidae. Thus, these are the only non-otolithic skeletal specimens of an Eocene hake known outside of the London Clay's †Rhinocephalus.
New Avian tracks from the lower to middle Eocene at Fossil Hill, King George Island, Antarctica
Authors: Mansilla Héctor G. , De Valais Silvina , Stinnesbeck Wolfgang , Varela Natalia A. , Leppe Marcelo A.
Published: May 2012

Trace fossils are long known to exist in the Fossil Hill Formation (lower to middle Eocene) at Fildes Peninsula, King George Island, Antarctica. During fieldwork in 2009, abundant new avian tracks were recovered, which are analysed here. Three avian ichnotaxa are distinguished. The most common impressions are tridactyls and tetradactyls with slender digit imprints II–IV and a posterior hallux. They are included in the ichnogenus Gruipeda. In addition tridactyl and tetradactyl footprints with short and thick digit impressions are conferred to Uhangrichnus. The third ichnotaxon is a tridactyl impression with broad and short digits assigned to Avipeda. The latter taxon is here documented for the first time from Antarctica. These avian tracks are preserved in volcaniclastic sediments consisting in reddish-brown layers of mudstone intercalated with coarse sandstone. The sequence represents lacustrine environments which seasonally dried and were episodically refilled.
Calcium and vitamin D in obesity
Authors: Song Qingming , Sergeev Igor N.
Published: May 2012

New and more effective nutritional measures are urgently needed for the prevention of obesity. The role of Ca and vitamin D in obesity has been recently implicated. Low Ca intake and low vitamin D status have been linked with an increased risk of obesity in epidemiological studies; however, clinical intervention trials designed to test this association have produced controversial results. The suggested anti-obesity mechanisms of Ca and vitamin D include the regulation of adipocyte death (apoptosis), adipogenesis and lipid metabolism. Dietary Ca has been also shown to increase faecal fat excretion. The potential role of Ca and vitamin D in shifting energy balance towards a more negative state is an area of considerable interest. Ultimately, a review of recent research findings does not allow the reaching of a definitive conclusion that increasing Ca intake and rising vitamin D status will influence fat mass and body weight or decrease the risk of obesity and overweight.
Principles of Emergency Department Facility Design for Optimal Management of Mass-Casualty Incidents
Authors: Halpern Pinchas , Goldberg Scott A. , Keng Jimmy G. , Koenig Kristi L.
Published: May 2012

Introduction

The Emergency Department (ED) is the triage, stabilization and disposition unit of the hospital during a mass-casualty incident (MCI). With most EDs already functioning at or over capacity, efficient management of an MCI requires optimization of all ED components. While the operational aspects of MCI management have been well described, the architectural/structural principles have not. Further, there are limited reports of the testing of ED design components in actual MCI events. The objective of this study is to outline the important infrastructural design components for optimization of ED response to an MCI, as developed, implemented, and repeatedly tested in one urban medical center.

Report

In the authors’ experience, the most important aspects of ED design for MCI have included external infrastructure and promoting rapid lockdown of the facility for security purposes; an ambulance bay permitting efficient vehicle flow and casualty discharge; strategic placement of the triage location; patient tracking techniques; planning adequate surge capacity for both patients and staff; sufficient command, control, communications, computers, and information; well-positioned and functional decontamination facilities; adequate, well-located and easily distributed medical supplies; and appropriately built and functioning essential services.

Discussion

Designing the ED to cope well with a large casualty surge during a disaster is not easy, and it may not be feasible for all EDs to implement all the necessary components. However, many of the components of an appropriate infrastructural design add minimal cost to the normal expenditures of building an ED.

Conclusion

This study highlights the role of design and infrastructure in MCI preparedness in order to assist planners in improving their ED capabilities. Structural optimization calls for a paradigm shift in the concept of structural and operational ED design, but may be necessary in order to maximize surge capacity, department resilience, and patient and staff safety.

Halpern P, Goldberg SA, Keng JG, Koenig KL. Principles of Emergency Department facility design for optimal management of mass-casualty incidents.Prehosp Disaster Med.2012;27(2):1-9.
A NOTE ON INDETERMINACY AND INVESTMENT ADJUSTMENT COSTS IN AN ENDOGENOUSLY GROWING SMALL OPEN ECONOMY
Authors: Chin Chi-Ting , Guo Jang-Ting , Lai Ching-Chong
Published: May 2012

This note analytically examines the interrelations between macroeconomic (in)stability and investment adjustment costs in a one-sector endogenously growing small–open economy representative-agent model. We show that under costly capital accumulation, the economy exhibits indeterminacy and sunspots if and only if the equilibrium wage–hours locus slopes upward and is steeper than the household's labor supply curve. By contrast, the economy without adjustment costs for capital investment always displays saddlepath stability and equilibrium uniqueness, regardless of the degree of increasing returns inaggregate production.
Global patterns in overweight among children and mothers in less developed countries
Authors: Van Hook Jennifer , Altman Claire E , Balistreri Kelly S
Published: May 2012

Objective

Past research has identified increases in national income and urbanization as key drivers of the global obesity epidemic. That work further identified educational attainment and urban residence as important moderators of the effects of national income. However, such work has tended to assume that children and adults respond in the same way to these factors. In the present paper, we evaluate how the socio-economic and country-level factors associated with obesity differ between children and their mothers.

Design

We modelled the associations between maternal education, country-level income and urban residence with mother's and children's weight status.

Setting

We analysed ninety-five nationally representative health and nutrition surveys conducted between 1990 and 2008 from thirty-three less developed countries.

Subjects

Our sample included children aged 2–4 years (n 253 442) and their mothers (n 228 655).

Results

Consistent with prior research, we found that mothers’ risk of overweight was positively associated with economic development, urban residence and maternal education. Additionally, economic development was associated with steeper increases in mothers’ risk of overweight among those with low (v. high) levels of education and among those living in rural (v. urban) areas. However, these associations were different for children. Child overweight was not associated with maternal education and urban residence, and negatively associated with national income.

Conclusions

We speculate that the distinctive patterns for children may arise from conditions in low- and middle-income developing countries that increase the risk of child underweight and poor nutrition.
Anaemia in pregnant women before and after the mandatory fortification of wheat and corn flours with iron
Authors: da Silva Cristina Lúcia , Saunders Cláudia , Szarfarc Sophia Cornbluth , Fujimori Elizabeth , da Veiga Glória Valéria
Published: May 2012

Objective

To estimate the frequency of anaemia in pregnant women before and after the fortification of flours with Fe.

Design

Retrospective study developed from secondary data obtained from medical records.

Setting

Two health units in Rio de Janeiro, Brazil.

Subjects

Socio-economic, demographic, obstetric and Hb concentration data were collected of 778 pregnant women attending prenatal care. Two study groups were created: the first referred to the period before fortification (G1, n 391), including women whose parturition happened before June 2004; and the second referred to the period after fortification (G2, n 387), including women whose last menstrual cycle happened after June 2005. The Hb cut-off point adopted for anaemia diagnosis was <11·0 g/dl.

Results

In linear regression models, when Hb concentration was expressed as a dependent variable, women in G2 presented Hb concentration 0·26 g/dl and 0·36 g/dl higher during the second and third trimesters of pregnancy, respectively, compared with G1. In logistic regression models where the dependent variable was anaemia during the second and third trimesters, it was verified that being a member of G2 was a protective factor against anaemia in the third trimester. Regarding the presence of anaemia at any gestational moment, it was verified that being a member of G2 represented a protective factor against anaemia during pregnancy.

Conclusions

Results indicate the protective effect of the fortification of flours with Fe in the fight against gestational anaemia, contributing to prevention and control of this nutritional disorder among pregnant women.
Fruit and vegetable consumption among migrants in Switzerland
Authors: Volken Thomas , Rüesch Peter , Guggisberg Jürg
Published: May 2012

Objective

To assess the relative risk of low daily fruit and vegetable consumption for six large migrant groups in Switzerland.

Design

Cross-sectional health survey carried out 2007 (Swiss Health Survey) and 2010 (Swiss Migrant Health Survey) in Switzerland. Multinomial logistic regression models were used to estimate relative risk rates (RRR) of migrants relative to Swiss nationals.

Setting

Data obtained from representative samples of Swiss and foreign nationals living in Switzerland.

Subjects

A random sample (n14637) of the Portuguese, German, Italian, Turkish, Serbian, Kosovan and Swiss permanent resident adult population (17–64 years old) was interviewed.

Results

The proportion of participants who adhered to the recommended fruit and vegetable consumption was below one-third in all study populations. Compared with Swiss nationals, the relative risk of low daily fruit and vegetable intake relative to recommended intake was higher in Turkish nationals (RRR = 2·92, 95 % CI 1·91, 4·48;P= 0·0000) and Kosovan nationals (RRR = 4·76, 95 % CI 3·01, 7·55;P= 0·0000). The respective relative risks of Portuguese, Serbian, German and Italian nationals were not significantly different from the Swiss reference group.

Conclusions

Initiatives for the promotion of fruit and vegetable consumption should continue to address the population at large. At the same time, programmes that are tailored to the specific needs of migrants from Turkey and Kosovo should be considered.
Opportunities and constraints to legume diversification for sustainable maize production on smallholder farms in Malawi
Authors: Mhango Wezi G. , Snapp Sieglinde S. , Phiri George Y.K.
Published: May 2012

Sustainable intensification of smallholder farms in Africa is highly dependent on enhancing biological nitrogen fixation (BNF). Legume diversification of maize-based systems is a core example of sustainable intensification, with the food security of millions of farm families at stake. This study highlights the constraints and opportunities associated with the adoption of legumes by smallholder farmers in southern Africa. A two-part survey of households and farm fields (n=88) was conducted in the Ekwendeni watershed of northern Malawi. Participatory research and education activities have been underway for over a decade in this region, resulting in expanded uptake of a range of legume species as intercrops and in rotation with the staple maize crop. Farmer adoption has occurred to a varying extent for soybean (Glycine max), pigeon pea (Cajanus cajan), velvet bean (Mucuna pruriens) and fish bean (Tephrosia vogelii). Farmers, working with the project valued pigeon pea and other legumes for soil fertility purposes to a greater extent than farmers not working with the project. Legumes were valued for a wide range of purposes beyond soil cover and fertility enhancement, notably for infant nutrition (at least for soybean), insect control, and vegetable and grain production for both market and home consumption. Literature values for BNF in tropical legumes range up to 170 kg N ha−1for grain and 300 kg N ha−1for green manure species; however, our field interviews illustrated the extent of constraints imposed by soil properties on smallholder fields in Malawi. The key edaphic constraints observed were very deficient to moderate phosphorus levels (range 4–142, average 33 mg kg−1), and moderately acid soils (range pH 5.1–7.9, average 6.2). The per farm hectarage devoted to legume production relative to maize production was also low (0.15 versus 0.35 ha), a surprising find in an area with demonstrated interest in novel legume species. Further, farmers showed a strong preference for legumes that produced edible grain, regardless of the associated nutrient removal in the harvested grain, and did not sow large areas to legume crops. These farm-level decisions act as constraints to BNF inputs in maize-based smallholder cropping systems. Overall, we found that legume productivity could be enhanced. We documented the value of policies and educational efforts that support farmers gaining access to high-quality seeds, amendments for phosphorus-deficient soils, and promotion of multipurpose legumes that build soils through leafy residues and roots, as well as providing grain for food security and sales.
An enhanced integral-equation formulation for accurate analysis of frequency-selective structures
Authors: Valerio Guido , Galli Alessandro , Wilton Donald R. , Jackson David R.
Published: May 2012

In this work, a very efficient mixed-potential integral-equation formulation is implemented for the rigorous analysis of multilayered structures with arbitrarily shaped two-dimensional periodic metallic and/or dielectric inclusions. Original acceleration techniques have been developed for the computation of the components of the scalar and dyadic Green's functions, based on different types of asymptotic extractions according to the potential considered. The theoretical approach and its computational convenience have been validated through different full-wave analyses concerning both scattering problems and complex-mode dispersive behaviors in various frequency-selective structures for microwave applications.
Rate and pattern of weight gain in Indian women from the upper income group during pregnancy and its effect on pregnancy outcome
Authors: Raje L. , Ghugre P.
Published: May 2012

Maternal weight gain and pattern of weight gain during pregnancy influence the ultimate outcome of pregnancy. Pregravid body mass index (BMI), maternal dietary intake, maternal height and age all determine the weight gain during pregnancy. The study was taken up with an objective to observe maternal weight gain and its pattern in pregnancy in women from an upper income group and to find out their association with pregnancy outcome. 180 normal primiparous pregnant Indian women (20–35 years) from an upper income group were recruited between the 10th and 14th weeks of pregnancy and were followed up throughout their pregnancy to record total and trimester-wise weight gain. Neonatal birth weights were recorded. The results showed that mothers with high pregravid BMI gained more weight during pregnancy than the recommended weight gain; in addition, weight gain in the first trimester was significantly correlated with birth weight of the neonates (P = 0.019). Significant correlation was found between weight gain in the third trimester and birth weight of the neonate irrespective of maternal BMI. The rate of weight gain was significantly correlated with neonatal birth weights irrespective of maternal pregravid BMI (P = 0.022) and as per its categories (P = 0.027). Thus, overall it can be concluded that adequate maternal nutrition before and during pregnancy is important for adequate weight gain by the mother and can result in better outcome of pregnancy. The rate of weight gain is also an important contributing factor.
The vertical distribution of iron stable isotopes in the North Atlantic near Bermuda
Authors: John Seth G. , Adkins Jess
Published: May 2012

Seawater dissolved iron isotope ratios (δ56Fe) have been measured in the North Atlantic near Bermuda. In a full‐depth profile, seawater dissolvedδ56Fe is isotopically heavy compared to crustal values throughout the water column (δ56FeIRMM‐014 = +0.30‰ to +0.71‰). Iron isotope ratios are relatively homogenous in the upper water column (between +0.30‰ to +0.45‰ above 1500 m), and δ56Fe increases below this to a maximum of +0.71‰ at 2500 m, decreasing again to +0.35‰ at 4200 m. The δ56Fe profile is very different from the iron concentration profile; in the upper water column [Fe] is variable while δ56Fe is relatively constant, and in the deeper water column δ56Fe varies while [Fe] remains relatively constant. The δ56Fe profile is also not well correlated with other hydrographic tracers in the North Atlantic such as temperature, salinity, or the concentrations of oxygen, phosphate, silica, and CFC‐11. The dissimilarity betweenδ56Fe profiles and profiles of [Fe] and other hydrographic tracers shows that Fe isotope ratios provide a unique sort of information about ocean chemistry, and they suggest that Fe isotopes may therefore be a valuable new tool for tracing the global sources, sinks, and biogeochemical cycling of Fe.
Southern Ocean control of silicon stable isotope distribution in the deep Atlantic Ocean
Authors: de Souza Gregory F. , Reynolds Ben C. , Rickli Jörg , Frank Martin , Saito Mak A. , Gerringa Loes J. A. , Bourdon Bernard
Published: May 2012

The fractionation of silicon (Si) stable isotopes by biological activity in the surface ocean makes the stable isotope composition of silicon (δ30Si) dissolved in seawater a sensitive tracer of the oceanic biogeochemical Si cycle. We present a high‐precision dataset that characterizes the δ30Si distribution in the deep Atlantic Ocean from Denmark Strait to Drake Passage, documenting strong meridional and smaller, but resolvable, vertical δ30Si gradients. We show that these gradients are related to the two sources of deep and bottom waters in the Atlantic Ocean: waters of North Atlantic and Nordic origin carry a high δ30Si signature of ≥+1.7‰ into the deep Atlantic, while Antarctic Bottom Water transports Si with a low δ30Si value of around +1.2‰. The deep Atlantic δ30Si distribution is thus governed by the quasi‐conservative mixing of Si from these two isotopically distinct sources. This disparity in Si isotope composition between the North Atlantic and Southern Ocean is in marked contrast to the homogeneity of the stable nitrogen isotope composition of deep ocean nitrate (δ15N‐NO3). We infer that the meridional δ30Si gradient derives from the transport of the high δ30Si signature of Southern Ocean intermediate/mode waters into the North Atlantic by the upper return path of the meridional overturning circulation (MOC). The basin‐scale deep Atlantic δ30Si gradient thus owes its existence to the interaction of the physical circulation with biological nutrient uptake at high southern latitudes, which fractionates Si isotopes between the abyssal and intermediate/mode waters formed in the Southern Ocean.
The role of shelf nutrients on glacial‐interglacial CO2: A negative feedback
Authors: Ushie Hiroyuki , Matsumoto Katsumi
Published: May 2012

In the past 800 thousand years and before industrialization, the largest variations in atmospheric CO2 concentration (pCO2) occurred in connection with the glacial cycles that characterized Earth's climate over this period. One curious feature of at least the last four glacial‐interglacial cycles is that atmospheric pCO2 reached about the same upper limit of 280 ppm during peak interglacial periods and about the same lower limit of 180 ppm during peak glacial periods. Here, we show using a numerical model of earth system that enhanced shelf sediment weathering during glacial sea level lowstands tends to raise pCO2 even after carbonate compensation and thus stabilize pCO2 from further reduction. This is because not all nutrients from weathering will be utilized by biology but more importantly because the spatial distributions of carbon and phosphorus from weathering become decoupled in such a way that carbon is preferentially stored in the upper ocean and phosphorus in the deep ocean. In addition, the C:P ratios in continental margin sediments are generally much higher than the Redfield ratio due to preferential remineralization of phosphorus in shelf sediment diagenesis. When these factors are accounted for in our model, the input of organic matter, which corresponds to the observed negative shift in ocean δ13C during glacial periods, raises pCO2 by approximately 14 ppm. The same mechanisms operating in the opposite directions during interglacial highstand tend to lower pCO2 and stabilize it from further increase. The impact of sea level‐driven continental shelf exposure and submersion of CO2 is therefore a negative feedback that may have contributed to limiting the variation of Pleistocene pCO2 to the observed 100 ppm range.
Potential role of inorganic polyphosphate in the cycling of phosphorus within the hypoxic water column of Effingham Inlet, British Columbia
Authors: Diaz Julia M. , Ingall Ellery D. , Snow Samuel D. , Benitez‐Nelson Claudia R. , Taillefert Martial , Brandes Jay A.
Published: May 2012

The upper basin of Effingham Inlet possesses permanently anoxic bottom waters, with a water column redox transition zone typically occurring at least 40 m above the sediment‐water interface. During our sampling campaign in April and July 2007, this redox transition zone was associated with sharp peaks in a variety of parameters, including soluble reactive phosphorus (SRP) and total particulate phosphorus (TPP). Based on sequential extraction results, TPP maxima exhibited preferential accumulation of an operationally defined class of loosely adsorbed organic phosphorus (P), which may contain a substantial fraction of polyphosphate (poly‐P). This poly‐P may furthermore be involved in the redox‐dependent remobilization of SRP. For example, direct fluorometric analysis of poly‐P content revealed that particulate inorganic poly‐P was present at concentrations ranging from 1 to 9 nM P within and several meters above the TPP maximum. Below the depth of 1% oxygen saturation, however, particulate inorganic poly‐P was undetectable (<0.8 nM in situ). Assuming this concentration profile reflects the remineralization of inorganic poly‐P to SRP across the redox transition, inorganic poly‐P degradation accounted for as much as 4 ± 3% (average ± standard deviation) to 9 ± 8% of the vertical turbulent diffusive SRP flux. This finding is a conservative estimate due in part to sample storage effects associated with our analysis of poly‐P content. By comparison, iron‐linked P cycling accounted for at most 65 ± 33% of the diffusive SRP flux, leaving ∼25% unaccounted for. Thus, while redox‐sensitive poly‐P remineralization in Effingham Inlet appears modest based on our direct conservative estimate, it may be higher from a mass balance viewpoint. Poly‐P cycling may therefore be an overlooked mechanism for the redox‐sensitive cycling of P in some hypoxic/anoxic boundaries, especially iron‐poor marine oxygen minimum zones.
Global importance, patterns, and controls of dissolved silica retention in lakes and reservoirs
Authors: Harrison John A. , Frings Patrick J. , Beusen Arthur H. W. , Conley Daniel J. , McCrackin Michelle L.
Published: May 2012

Lentic water bodies (lakes and reservoirs) offer favorable conditions for silica (SiO2) burial in sediments. Recent global estimates suggest that (1) lentic SiO2 trapping is a globally important SiO2 flux, and (2) through reservoir construction, humans have dramatically altered river dissolved SiO2 (DSi) transport and coastal DSi delivery. However, regional to global scale patterns and controls of DSi removal in lentic systems are poorly constrained. Here we use 27 published lake and reservoir DSi budgets to develop insights into patterns and controls of lentic DSi retention and to develop a new, spatially explicit, global model of lentic DSi removal called SiRReLa (Silica Retention in Reservoirs and Lakes). In our analysis, lentic DSi removal (kg SiO2 yr−1) was significantly and positively related to DSi loading (P < 0.0001; r2 = 0.98), and DSi removal efficiency was significantly and positively related to water residence time (P < 0.0001; r2 = 0.68). In addition, DSi settling rates were, on average, 6.5‐fold higher in eutrophic systems than in non‐eutrophic systems (median settling velocities: 11.1 and 1.7 m yr−1 for eutrophic and non‐eutrophic systems, respectively; P < 0.01). SiRReLa, which incorporates these insights, performed quite well in predicting both total DSi removal (kg SiO2 yr−1; Nash Sutcliffe Efficiency (N.S.E) = 0.88) and DSi removal efficiency (% Si removed; N.S.E. = 0.75), with no detectable bias in the model. Global application of SiRReLa confirms that lentic systems are important sinks for DSi, removing 89.1 Tg DSi yr−1 from watersheds globally, roughly 19–38% of all DSi inputs to surface waters. Small lakes and reservoirs (<50 km2) were critical in the analysis, retaining 81% (72 Tg DSi yr−1) of the globally retained total. Furthermore, although reservoirs occupy just 6% of the global lentic surface area, they retained approximately 35% of the total DSi removed by lentic systems. Regional hot spots for lentic DSi removal were identified and imply that lentic systems can remove the vast majority of DSi across a large fraction of Earth's land surface. Finally, a sensitivity analysis indicates that future improvements in DSi trapping and transport models should focus on improving estimates of DSi input to surface waters.
A comparison of the atmospheric conditions at Eureka, Canada, and Barrow, Alaska (2006–2008)
Authors: Cox Christopher J. , Walden Von P. , Rowe Penny M.
Published: May 2012

It is now well understood that the Arctic is particularly sensitive to climate change. Arctic sea ice is already undergoing significant changes. Some of the recent decrease in sea ice extent is due to changes in the surface energy budget, including the effect of clouds. Accurate ground‐based measurements of atmospheric and cloud properties are valuable for estimating components of the surface energy budget. In this paper, measurements made between 2006 and 2008 at the Canadian Network for the Detection of Arctic Change (CANDAC) site at Eureka, Nunavut, Canada (80°N, 86°W) and the Atmospheric Radiation Measurement (ARM) program site at Barrow, Alaska (71°N, 156°W) are used to examine differences in the atmospheres over the two sites, including the temperature, humidity, winds, and the downwelling longwave radiation flux. A method is developed to convert infrared radiances to downwelling longwave fluxes since broadband measurements of flux were not available at Eureka during the study period; the method is validated by comparing the fluxes at Barrow to independent measurements made by a pyrgeometer. Comparisons of the derived fluxes show significant differences between the two sites. Eureka is consistently colder and drier than Barrow, and the infrared effect of clouds on the surface energy budget is less. To examine the meteorological conditions that cause such differences, the ERA‐Interim reanalysis model is used; it is chosen over other models because it provides the best reproduction of longwave radiation at the surface. We find that the location of Eureka predisposes it to cold and dry air masses from the central Arctic Ocean and the Greenland Ice Sheet. In contrast, the air masses at Barrow come from a variety of directions, some of which are relatively warm and moist.
Newly established AGU awards and lecture
Authors: Paredes Beth , Kumar Mohi
Published: May 2012

The Sulzman Award for Excellence in Education and Mentoring (Biogeosciences section) recognizes AGU members who have sustained an active research career in a field related to biogeosciences while excelling as teachers and serving as role models for the next generation of female scientists. This new award acknowledges the importance of female mentors in enhancing gender balance in physical science career paths. The award is being endowed to honor Elizabeth Sulzman, an isotope biogeochemist and soil scientist, whose enthusiasm for teaching awed many undergraduates at Oregon State University. Current plans are to present the first Sulzman award at the 2013 Fall Meeting. Applicants must be women who are within 15 years of receiving their Ph.D., and nomination packages should include a cover letter, resumé, and three letters of recommendation. As they become available, more details will be posted on the Biogeosciences section Web site (http://www.agu.org/sections/biogeo/). The award will provide up to $1000 to one successful nominee each year, although the exact monetary amount is yet to be determined. AGU is currently accepting donations to endow this award; contact Victoria Thompson (vthompson@agu.org) to get involved.
The emergence of zonal ocean jets under large‐scale stochastic wind forcing
Authors: O'Reilly Christopher H. , Czaja Arnaud , LaCasce J. H.
Published: May 2012

The response of a two‐layer quasigeostrophic ocean model to basin scale stochastic wind forcing is investigated. As found in many previous studies, long Rossby waves are excited at the eastern boundary of the square model basin and the waves are baroclinically unstable. A novel aspect we focus on here is that the instability leads to the generation of zonal jets throughout the domain. The jets are actually wave‐like in nature, and result directly from the instability. The “jets” appear when averaging the oceanic zonal velocity field over fixed periods of time. The longer the averaging period, the weaker the jets as the latter are in fact time‐varying. The jets occur for a wide range of stratification, strength of stochastic forcing and the presence or not of a time mean circulation. The mechanism of jet generation described here thereby provides an explanation for the recent observations of alternating zonal jets in the mid‐latitude oceans.
Observed Trends in Wind Speed over the Southern Ocean
Authors: Hande L. B. , Siems S. T. , Manton M. J.
Published: May 2012

Most studies of trends in regional climate focus on temperature, however for maritime environments in particular, changes in the wind are equally important. An analysis of trends in the wind over Macquarie Island is performed with a radio‐sonde database spanning nearly four decades. The results indicate that the surface wind speed is increasing, with the trend for the upper levels being less well defined. The surface wind is highly correlated with the upper level winds, and the wind at all levels are moderately correlated with the Southern Annular Mode. ECMWF ERA‐Interim reanalysis data shows significant trends in wind speed over several levels, however slightly smaller than trends in the soundings over a similar time period. The correlations in ERA‐Interim are similar to those in the soundings. A clustering analysis of the wind reveals four distinct regimes, with a trend towards a regime characterised by strong north westerly winds.
On the influence of a β‐effect on Lagrangian diffusion
Authors: Lacorata Guglielmo , Espa Stefania
Published: May 2012

Geophysical turbulence is strongly influenced by the variation of the Coriolis force with latitude (β‐effect): when this effect is significant an anisotropic inverse cascade is developed since energy is preferentially transferred towards zonal modes. The consequent emergence of flow structures along the zonal direction can strongly impact turbulent transport and modify meridional scalar diffusion. In this letter we investigate zonal and meridional diffusion in laboratory experiments of turbulence affected by aβ‐effect. The degree of anisotropy and the flow characteristic scales have been quantified according to a Lagrangian approach based on the reconstruction of tracer trajectories, i.e., in analogy with oceanic drifters data, and on the Finite‐Scale Lyapunov Exponent (FSLE) analysis. An experimental confirmation of a recently introduced scaling law for the meridional diffusion in the marginally zonostrophic regime is also presented.
No Evidence for Additional Blood–Brain Barrier P-Glycoprotein Dysfunction in Alzheimer's Disease Patients with Microbleeds
Authors: van Assema Daniëlle ME , Goos Jeroen DC , van der Flier Wiesje M , Lubberink Mark , Boellaard Ronald , Windhorst Albert D , Scheltens Philip , Lammertsma Adriaan A , van Berckel Bart NM
Published: May 2012

Decreased blood–brain barrier P-glycoprotein (Pgp) function has been shown in Alzheimer's disease (AD) patients using positron emission tomography (PET) with the radiotracer ( R)-[11C]verapamil. Decreased Pgp function has also been hypothesized to promote cerebral amyloid angiopathy (CAA) development. Here, we used PET and ( R)-[11C]verapamil to assess Pgp function in eighteen AD patients, of which six had microbleeds (MBs), presumably reflecting underlying CAA. No differences were found in binding potential and nonspecific volume of distribution of ( R)-[11C]verapamil between patient groups. These results provide no evidence for additional Pgp dysfunction in AD patients with MBs.
The proteomic future: where mass spectrometry should be taking us
Authors: Thelen Jay J. , Miernyk Ján A.
Published: May 2012

A newcomer to the -omics era, proteomics, is a broad instrument-intensive research area that has advanced rapidly since its inception less than 20 years ago. Although the ‘wet-bench’ aspects of proteomics have undergone a renaissance with the improvement in protein and peptide separation techniques, including various improvements in two-dimensional gel electrophoresis and gel-free or off-gel protein focusing, it has been the seminal advances in MS that have led to the ascension of this field. Recent improvements in sensitivity, mass accuracy and fragmentation have led to achievements previously only dreamed of, including whole-proteome identification, and quantification and extensive mapping of specific PTMs (post-translational modifications). With such capabilities at present, one might conclude that proteomics has already reached its zenith; however, ‘capability’ indicates that the envisioned goals have not yet been achieved. In the present review we focus on what we perceive as the areas requiring more attention to achieve the improvements in workflow and instrumentation that will bridge the gap between capability and achievement for at least most proteomes and PTMs. Additionally, it is essential that we extend our ability to understand protein structures, interactions and localizations. Towards these ends, we briefly focus on selected methods and research areas where we anticipate the next wave of proteomic advances.
Low threshold field emission from high-quality cubic boron nitride films
Authors: Teii Kungen , Matsumoto Seiichiro
Published: May 2012

Field emission performance of materials with mixed sp2/sp3 phases often depends upon the phase composition at the surface. In this study, the emission performance of high-quality cubic boron nitride (cBN) films is studied in terms of phase purity. Thick cBN films consisting of micron-sized grains are prepared from boron trifluoride gas by chemical vapor deposition in a plasma jet and an inductively coupled plasma. Both the bulk and surface phase purities as well as crystallinities of cBN evaluated by visible and ultraviolet Raman spectroscopy, glancing-angle x-ray diffraction, and x-ray photoelectron spectroscopy are the highest when the film is deposited in a plasma jet under an optimized condition. The emission turn-on field decreases with increasing the phase purity, down to around 5 V/μm for the highest cBN purity, due to the larger field enhancement, while it is higher than 14 V/μm without cBN (sp2-bonded hexagonal BN only). The results indicate that the total field enhancement for the high phase purity film is governed by the internal field amplification related to the surface coverage of more conductive cBN, rather than the external one related to the surface topology or roughness.
Interface trap generation and recovery mechanisms during and after positive bias stress in metal-oxide-semiconductor structures
Authors: Samanta Piyas , Huang Heng-Sheng , Chen Shuang-Yuan , Tzeng Tsung-Jian , Wang Mu-Chun
Published: May 2012

Interface trap (Nit) generation and their partial recovery during and after cessation of the positive bias-temperature stress (PBTS) in n-type metal-oxide-semiconductor capacitors have been investigated. The analysis of experimental results indicates that Nit creation is caused by the depassivation of Si3≡Si-H bonds at the Si/SiO2 interface by the atomic neutral hydrogen (H0) cracked via electron impact at or near gate/oxide interface during electron injection from the substrate. Nit recovery after interruption of the stress is due to back diffusion of H2 species toward the Si/SiO2 interface and repassivation of Si3≡Si• dangling bonds. We propose that in absence of holes, a modified one dimensional reaction-diffusion (R-D) model following three step degradation sequences can qualitatively explain the generation and the recovery of Nit during and after PBTS.
Rashba spin-orbit effect on tunneling time in graphene superlattice
Authors: Faizabadi Edris , Sattari Farhad
Published: May 2012

Based on transfer-matrix and stationary phase methods, we have investigated the tunneling time (group delay time) through monolayer graphene superlattice in the presence of Rashba spin-orbit interaction. It is found that the tunneling time has an oscillatory behavior with respect to Rashba spin-orbit interaction strength. Furthermore, the tunneling time for normal incident angle is independent of spin state of electron, while for oblique incident angles, it depends on the spin state of electron. It is also shown that, for normal incident, the Hartman effect vanishes, while for oblique incident, the Hartman effect appears whenever the x (the growth direction of superlattice) component of the electron wave vector inside the barriers is imaginary.