bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy and Safety of Oral Eplerenone in Acute Central Serous Chorioretinopathy: A Randomised Controlled Study
Authors: Sarkar Avik Dey , Thakur Sanjay Kumar Daulat , Biswas Smaranjit , Sarkar Ajoy Dey , Sarkar Sanchari
Published: February 2024

Introduction: Acute Central Serous Chorioretinopathy (CSCR) is an important form of acquired maculopathy that usually presents as localised serous detachment of the neurosensory retina. Although, the disease is typically self limiting over a period of 2-3months, a percentage of patients ultimately develop chronic RPE changes. Eplerenone, a potential Mineralocorticoid Receptor (MR) antagonist, may play a role in regulating choroidal vascularity and modifying the disease in chronic CSCR. Aim: To assess the safety and efficacy of oral eplerenone medication in acute CSCR. Materials and Methods: This was a randomised controlled trial that included 162 eyes of 162 patients with acute CSCR. Patients were divided into two groups– Group-A, which received oral Eplerenone, and Group-B, which received Placebo therapy. Each group comprised 81 eyes. Best Corrected Visual Acuity (BCVA), Central Macular Thickness (CMT), and serum potassium (K+) levels were measured at baseline and monthly intervals for three consecutive months. Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) Statistics version 20 software (IBM Corp., Armonk, NY, USA). A p-value less than 0.05 was considered statistically significant. Results: The differences in CMT in Group-A and Group-B were 279±56.41µm and 207±68.88 µm (p<0.01) at the end of the first month and 361±33.56 µm and 278±46.27 µm at three months (p<0.01), respectively. The average BCVA improvement in Group-A and Group-B was 6.05 lines and 4.21 LogMAR lines, respectively, at the conclusion (p=0.002). Deterioration to chronicity was seen in 3.7% of the eyes in Group A and 17.3% of the eyes in Group B. The increase in Serum K+ at three months was 0.61±0.27 mg/dL in Group-A and 0.1±0.21 mg/dL in Group-B (p=0.03). Conclusion: Eplerenone is a safe and effective first-line treatment option for acute CSCR, leading to faster and higher resolution with protection from progression to chronicity.
Impact of Integrated Farming System on Doubling Farmers’ Income
Authors: Ruikar B. A.  , Gaikawad A. B.  , Kharge A. P.  , Kadam J. R.  , Maske K. V.
Published: February 2024

The present study was undertaken with the main objective impact of integrated farming system on doubling farmers’ income. The study was conducted in four district of Konkan region of Maharashtra namely Ratnagiri, Sindhudurg, Raigad and Palghar district. In all 200 respondents were selected by using multi stage sampling techniques. The “Ex-Post-Facto” research design was used for conducting the study. The data were collected through the personal interview. The data collected were processed and statistically analyzed by using statistical technique like frequency, percentage, mean, standard deviation and chi square test. The analysis of data revealed that majority (104.00 per cent) change percent in income was occurred in agriculture + dairy farming system followed by agriculture + horticulture + fishery (85.00 per cent),  agriculture + poultry (82.00 per cent),agriculture + horticulture + poultry + dairy (84.00 per cent), agriculture + poultry (82.00 per cent), agriculture + Horticulture +poultry (76.00 per cent)agriculture +poultry + dairy  (74.00 per cent) agriculture + horticulture + dairy (73.00 per cent), agriculture + poultry + goat rearing (66.00 per cent), agriculture+ horticulture + goat rearing (62.00 per cent), agriculture +poultry + goat rearing + horticulture (60.00 per cent), agriculture + goat rearing (58.00 per cent) and agriculture + dairy + goat rearing (14.00 per cent).
The Effectiveness of Neighborhood Fund Programs on Regional Development in the Siantar Marimbun Sub-District from a Community-driven Development Perspective
Authors: Manurung Intan Ganisha Chintia , Lubis Satia Negara , Badaruddin
Published: February 2024

The aim of this research is to determine the effectiveness of neighborhood fund management through the lens of Community-Driven Development. Purposive sampling was used in this study, with a sample size of 100 individuals. The researcher employed a quantitative method with SEM-PLS analysis technique. The findings indicate that neighborhood funds, under the Community-Driven Development approach, significantly influence the development of neighborhood infrastructure but do not significantly affect community empowerment in the Siantar Marimbun Sub-District. The Neighborhood Fund Program for regional development achieves an effectiveness ratio of 98%. This suggests that the management of neighborhood funds in the Siantar Marimbun Sub-District in 2020 still focuses on physical programs (infrastructure) and has yet to emphasize community empowerment development, partly due to the COVID-19 pandemic and the absence of specific guidelines regarding the allocation percentage for infrastructure development versus community empowerment in Mayor Regulation No. 13 of 2019 for Pematangsiantar.
Water Demand and Availability in the Tarutung District, North Tapanuli Regency, Indonesia
Authors: Simanungkalit Binner Julianto , Nasution Zulkifli , Revida Erika
Published: February 2024

This comprehensive study addresses the intricate dynamics of population growth, water demand, and availability in the Tarutung District. Employing a geometric approach, we projected the population growth from 2018 to 2032, estimating a 0.74% annual increase. Subsequently, a meticulous water demand analysis encompassed domestic sectors, including household connections and public hydrants, and non-domestic sectors such as educational, religious, market, health, and commercial facilities. The calculated total water demand, encompassing both domestic and non-domestic needs, reached 6,034,026.38 liters per hour and 123,552,000 liters per hour, respectively. In parallel, we investigated the water availability through an examination of spring sources and rainfall data, revealing a substantial surplus. As of now, Tarutung District boasts a surplus water availability of 183,326,289.18 cubic meters per year. In conclusion, the findings indicate that, under current conditions, the Tarutung District is well-equipped to manage its water resources until 2032. However, the study underscores the importance of implementing sustainable environmental policies to safeguard water sources and optimize resource management. The proposed recommendations advocate for local government interventions, community awareness initiatives, water use efficiency enhancements, infrastructure improvements, and stringent forest area management. This research contributes valuable insights to water resource management, emphasizing the need for proactive measures to sustain the water abundance in the Tarutung District. The conclusions drawn and recommendations presented serve as a foundation for informed decision-making, aligning with the broader goals of environmental sustainability and community resilience.
Evaluation of Heavy Metal Contamination in Apple, Orange, and Watermelon Retailed Along Roadsides in Okinni, Egbedore Local Government, Osun State, Nigeria
Authors: Iyabode Adegbite Kabirat , Olusegun Oladeji Francis , Taofik Towolawi Adeleke , Folasade Adedokun Halimot
Published: February 2024

The escalating concern of heavy metal contamination in fruits underscores the need to evaluate associated health risks linked to their consumption. This study undertook assessment of heavy metal levels in commonly consumed fruits (orange, watermelon, and apple) retailed by roadside vendors in Okinni, Egbedore Local Government Area, Osun State. Data collection encompassed a meticulously designed questionnaire while 27 fruit samples (nine fruit each) were randomly procured from diverse market for laboratory analysis. Descriptive statistics, including frequency distribution, mean, and standard deviation, were computed for each heavy metal. The study discerned that majority of vendors predominantly procured their fruits from local farms, implemented the use of fertilizers or pesticides, employed baskets for storage and transportation, and generally held positive perspectives regarding the safety of fruits dispensed by roadside vendors. The results of heavy metal concentration averages in the sampled fruits fell within the permissible limits established by the World Health Organization (WHO) guidelines for safe levels in food. However, noteworthy concentrations of certain heavy metals, particularly As and Cr, were identified, signaling potential health risks for consumers. These findings underscore the ongoing necessity for rigorous monitoring and regulation of heavy metals in food, coupled with adherence to recommended dietary guidelines and safety standards to safeguard public health.
SARS-CoV-2 Infection and Factors Associated with Mortality in Hospitalized Patients Aged 60 and Over at the Epidemic Treatment Center (ETC) of Saint-Louis (Senegal)
Authors: Dièye Alassane , Diouf Arona , Diouf Papa Latyr Junior , Diedhiou Moustapha , Diakhaby Mba Bambo , Makalou Demba , Niang Samba , Dia-Gueye Diatou , Dia Amadou Diop , Dieng Ibrahima Louis Martin , Dieng Ahmeth , Lô Seynabou , Dia-Badiane Ndéye Méry
Published: February 2024

Background: SARS-CoV-2 infection typically causes severe pneumonia in elderly patients with high mortality rates.

Aim: This study aimed to describe the epidemiological, clinical, paraclinical and evolution profile of the SARS-CoV-2 infection in patients aged 60 years and over hospitalized at the Epidemic Treatment Center (ETC) of Saint-Louis “Senegal”, and to identify the factors associated with death.

Methodology: This is a cross-sectional, retrospective, descriptive and analytical study conducted from March 2020 to August 2021. It includes all patients aged 60 years and older hospitalized at the ETC of Saint-Louis (Senegal) for SARS-CoV-2 infection.  Microsoft Excel was used to enter data and then analysis was done using EPI INFO version 7 software.

Results: Of a total of 448 hospitalizations, 188 patient records aged 60 years and older was collected. The prevalence was 42%. The mean age was 70 years (±8 years). The sex ratio was 1.7 with a male predominance (62.8%). Hypertension was the most common co-morbidity (67%). Severe forms were predominant (64.4%). Dyspnea (60.3%), cough (56.5%) and ageusia (24.5%) were the most common symptoms on admission. Thoracic CT scans showed severe involvement in 51.7% of cases. Hydroxychloroquine-azithromycin combination was prescribed in 98.4% of cases. The mortality rate was 18.6%. The main factors associated with death were age (≤75 years) (p=0.014) [OR=0.488; 95% CI: 0.201-1.187]; critical forms (p=0.017) [OR=0.061; 95% CI: 0.006-0.601]; comorbidity (p=0. 031) [OR=1.647; 95% CI: 0.280-2.499]; occurrence of complications (p=0.009) [OR=1.212; 95% CI: 0.530-2.774]; and SpO2≤95% at admission (p=0.031) [OR=4.899; 95% CI: 0.752-8.797].

Conclusion: SARS-CoV-2 infection in the elderly is predominantly severe with high mortality. This high-risk group requires special attention.
Biodegradation of Chlorpyrifos Insecticide by Bacillus cereus ST06 and Chryseobacterium sp 6024 Isolated from Agricultural Soil, Nigeria
Authors: Elochi Emeribe, Chiemeka , Chinedu Onuorah Samuel
Published: February 2024

Introduction: Indigenous soil bacteria have the potential to degrade the harmful  chlorpyrifos insecticide, this identifies the importance of biodegradation as an eco-friendly method for chemical pollutant cleanup.

Aims: To compare the potential of Bacillus cereus ST06 and Chryseobacterium sp 6024 in biodegrading chlorpyrifos insecticide singly or as a consortium in a liquid medium.

Study Design: Enrichment culture technique was used to evaluate the bacterial potential in  biodegrading chlorpyrifos insecticide.

Place and Duration of Study: Agricultural soil sample containing chlorpyrifos degrading bacteria was obtained from Ukukwa village Amansea Nigeria (6o16' 30'' N and 7o 07'30''E) from depths of 15cm. Experiment was conducted from January till March 2022.

Methodology: In this study, previously isolated and characterized Bacillus cereus ST06 and Chryseobacterium sp 6024 by standard microbiological method based on their phenotypic test, biochemical test, cultural morphology and 16S rRNA sequencing was used for the experiment. Their growth response to 20mg/l and 60mg/l chlorpyrifos in mineral salts medium singly and as a consortium was compared and determined by monitoring the optical density at 600nm at the optimum condition of pH 6.5 and 30oC temperature for 28 days. The residual chlorpyrifos concentration after 28 days was also  compared and determined using Gas Chromatography- Electron Cathode Detector (GC-ECD).

Results: The result showed a significant difference (P< .001) as Bacillus cereus ST06 and Chryseobacterium sp 6024 responded differently to different concentration of chlorpyrifos.  Bacillus cereus ST06 and Chryseobacterium sp 6024 reached maximum growth in medium containing 20mg/l chlorpyrifos with a mean OD of 0.23±0.20 and 0.42±0.02 respectively on  16th day than 60mg/l chlorpyrifos with a mean OD of 0.47±0.02 and 0.81±0.02 respectively on 20th day. The bacterial consortium also reached maximum growth on 20mg/l and 60mg/l of chlorpyrifos with mean OD of 0.21±0.31 and 0.29±0.02 on 20th day respectively. The result of residual chlorpyrifos concentration shows that the bacteria consortium degraded 79 per cent and 78 per cent of 20mg/l and 60mg/l chlorpyrifos respectively, while Bacillus cereus ST06 and Chryseobacterium sp 6024 degraded 63 per cent and 57 per cent of 20mg/l chlorpyrifos and 61 per cent and 37 per cent of 60mg/l chlorpyrifos.

Conclusion: The study shows that bacteria consortium possessed potential to be used in biodegradation of 20mg/l and 60mg/l Chlorpyrifos than the individual isolates. It is therefore recommended that further studies on RNA profiling of each bacterium and synergistic interaction of the bacterial consortium be studied to better understand regulation of genes and individual bacterial roles in degradation chlorpyrifos efficiently.
corda bamba e a democracia equelibrista
Authors: Rios Costa Caroline
Published: February 2024

Após experiências ditatoriais e/ou autoritárias, convencionou-se que no momento de mudança de um regime político para outro, deveria ser implementado um processo de justiça de transição. Com parâmetros-base, sendo um deles a concessão de reparações, fica a cargo dos Estados nacionais elaborar como se dará a transição política, a implementação de uma justiça transicional, quando e quais os mecanismos que serão acionados, dentre outras questões. No Brasil, o processo de justiça de transição se iniciou depois do fim da ditadura, nos anos 1980, e seguiu tendo avanços ao longo dos anos 1990, 2000 e 2010. Nosso objetivo é analisar o conceito de justiça de transição, observar as tensões entre os diferentes atores políticos, como se deu o seu processo e a aplicação de reparações no país.
Ditadura e Estado Autoritário
Authors: Sena Junior Carlos Zacarias de , Lins Marcelo da Silva , Sobral Thasio Fernandes
Published: February 2024

Apresentação do Dossiê "Ditadura e Estado Autoritário". Nesta edição disponibilizamos 6 artigos que compõem o dossiê intitulado Ditadura e Estado Autoritário, organizado pelo professor doutorando Thasio Fernandes Sobral (UFBA) e os professores doutores Carlos Zacarias de Sena Junior (UFBA) e Marcelo da Silva Lins (UESC).
CSP theorems for communicating B machines
Authors: Schneider Steve , Treharne Helen
Published: November 2005

Recent work on combining CSP and B has provided ways of describing systems comprised of components described in both B (to express requirements on state) and CSP (to express interactive and controller behaviour). This approach is driven by the desire to exploit existing tool support for both CSP and B, and by the need for compositional proof techniques. This paper is concerned with the theory underpinning the approach, and proves a number of results for the development and verification of systems described using a combination of CSP and B. In particular, new results are obtained for the use of the hiding operator, which is essential for abstraction. The paper provides theorems which enable results obtained (possibly with tools) on the CSP part of the description to be lifted to the combination. Also, a better understanding of the interaction between CSP controllers and B machines in terms of
non-discriminating
and
open
behaviour on channels is introduced, and applied to the deadlock-freedom theorem. The results are illustrated with a toy lift controller running example.
The maintenance of intraspecific biodiversity: the interplay of selection on resource use and on natural enemy resistance in the pea aphid
Authors: Ferrari Julia , Godfray H. Charles J.
Published: November 2005

Biodiversity has both intraspecific and interspecific components, and speciation is the process through which the former is converted to the latter. Ecological factors can cause population divergence and differentiation. In this paper, we investigate the interplay between top‐down effects from natural enemies and bottom‐up effects from host plants in an aphid model system. Pea aphids, Acyrthosiphon pisum, are known to form host‐adapted races on Trifolium and Medicago. Here, replicate clones of pea aphids collected from a broader set of five host plant genera are screened for their performance on the same set of host plants and also for their resistance to four natural enemies: the parasitoids Aphidius eadyi and Aphidius ervi, and the entomopathogenic fungi Pandora (=Erynia) neoaphidis and Zoophthora phalloides. The populations showed clear adaptation to their host plant from which they were collected, but they also performed well on Vicia. Performance on the other three plant species was poor. The aphid population collected from Lotus was significantly better at defending itself against the parasitoid A. eadyi, and there was a tendency for the clones from Trifolium to be resistant to the pathogen P. neoaphidis. These patterns highlight the importance of understanding the ecological processes influencing speciation in the context of the web of ecological adaptations within which a species is embedded.
USE OF ‘SENSE OF COHERENCE (SOC)’ SCALE TO MEASURE RESILIENCE IN ERITREA: INTERROGATING BOTH THE DATA AND THE SCALE
Authors: ALMEDOM ASTIER M. , TESFAMICHAEL BERHE , SAEED MOHAMMED ZEIN , MASCIE-TAYLOR C. G. N. , ALEMU ZEMUI
Published: November 2005

An adapted ‘sense of coherence’ scale short form (SOC-13) was administered in nine languages of Eritrea with a total of 265 participants (162 women and 103 men) in order to assess ‘resilience’ in quantitative terms. Statistical analysis yielded significant differences in SOC scores between the displaced and non-displaced: mean=54·84 (SD=6·48) in internally displaced person (IDP) camps, compared with mean=48·94 (SD=11·99) in urban and rural settlements (t=3·831, p<0·001). Post-hoc tests revealed that the main difference is between IDP camp dwellers and urban (non-displaced) residents. Those in rural but traditionally mobile (pastoralist or transhumant) communities scored more or less the same as the urban non-displaced – i.e. significantly higher than those in IDP camps (p<0·05). Analysis of variance showed that displacement has a significantly negative effect on women compared with men (RR=0·262, p<0·001). Repeating the analysis for the three groups confirmed that urban and pastoralist/transhumant groups are similar, while women in IDP camps are lower scoring (RR=0·268, p<0·001), Hamboka women being worst affected due to their experience of serial displacement. These findings are interpreted and discussed in the light of qualitative information gleaned from the study participants’ interrogation of the content of the SOC scale; and in the wider context of historical, socio-political and cultural characteristics of Eritrea. The study’s implications for humanitarian and public health policy are considered.
Stress, tone and discourse prominence in the Curaçao dialect of Papiamentu
Authors: Remijsen Bert , van Heuven Vincent J.
Published: November 2005

This paper investigates the word-prosodic system of the Curaçao dialect of Papiamentu. Curaçao Papiamentu has both lexically distinctive stress and, independently, a word-level tone contrast. On the basis of a detailed acoustic investigation of this tonal contrast, we propose a privative phonological interpretation of the tone contrast, similar to proposals for the Scandinavian word-accent systems (Riad 1998, to appear). As compared to previous treatments of Curaçao Papiamentu word prosody, our hypothesis makes crucial reference to intonation and to tonal underspecification. We also investigate the realisation of primary and secondary stress in Curaçao Papiamentu.
Surface integral equation formulations for solving electromagnetic scattering problems with iterative methods
Authors: Ylä‐Oijala P. , Taskinen M. , Järvenpää S.
Published: November 2005

In this paper, formulation of the surface integral equations for solving electromagnetic scattering by dielectric and composite metallic and dielectric objects with iterative methods is studied. Four types of formulations are considered: T formulations, N formulations, the combined field integral equation formulation, and the Müller formulation. By studying properties of the integral equations and their testing in the Galerkin method, “optimal” forms for each formulation type are derived. Numerical examples demonstrate that the developed new formulations lead to clear improvements in the convergence rates when the matrix equations are solved iteratively with the generalized minimal residual method. Both the Rao‐Wilton‐Glisson and Trintinalia‐Ling (TL) basis functions are used in expanding the unknown electric and magnetic surface current densities. In particular, the first‐order TL basis functions are required in the N formulations to maintain the solution accuracy when the surfaces include sharp edges.
Ultrawideband beam summation algorithms for focusing near curved interfaces
Authors: Katsav Michael , Shlivinski Amir , Heyman Ehud
Published: November 2005

Two ultrawideband Gaussian beam summation (UWB‐GBS) algorithms are presented and then explored in the context of calculating UWB focusing by curved interfaces. The favorable features of the basic algorithm are: (1) The same lattice of beams is used for all frequencies, and (2) it utilizes isodiffracting Gaussian beams with frequency‐independent propagation parameters, which also yield stable and localized expansion coefficients for all frequencies. We then present a modified multiband algorithm that is more efficient if the signal bandwidth is larger than one octave. Here the signal bandwidth is divided into a self‐consistent hierarchy of one‐octave subbands such that the beam sets at the lower‐frequency bands are decimated subsets of those at the highest band, so that only the set of GBs at the highest band needs to be traced, while for the lower bands one may use properly decimated subsets. The numerical example demonstrates the effectiveness, the localization, and the uniformity of the UWB‐GBS representation in the focal zone. Concluding remarks contain comparisons between the proposed method and Kirchhoff aperture‐based alternatives.
Rapid forearc uplift and subsidence caused by impinging bathymetric features: Examples from the New Hebrides and Solomon arcs
Authors: Taylor F. W. , Mann Paul , Bevis M. G. , Edwards R. L. , Cheng Hai , Cutler Kirsten B. , Gray S. C. , Burr G. S. , Beck J. W. , Phillips David A. , Cabioch G. , Recy J.
Published: November 2005

Isotopically dated corals from the central New Hebrides and New Georgia Island Group, Solomon Islands, indicate that both forearcs underwent rapid late Quaternary subsidence that was abruptly replaced by hundreds of meters of uplift at rates up to ∼8 mm/yr, while total plate convergence was only a few kilometers. Two mechanisms that might account for these rapid reversals in vertical motion include (1) a “displacement” mechanism in which the forearc is displaced upward by the volume of an object passing beneath on the subducting plate (as the object moves deeper and vacates the base of the forearc, the forearc subsides to near its original position) and (2) a “crustal shortening” mechanism in which the forearc thickens and uplifts because of horizontal shortening when a large object impinges on the forearc and abruptly increases interplate coupling on the shallow end of the main thrust zone. Rapid subsidence follows when the impinging object is broken or otherwise decoupled, shallow interplate coupling becomes weak, and the uplifted forearc extends and subsides. The displacement mechanism surely plays a role on timescales over which plates converge tens of kilometers, but it fails to explain the geographic pattern, short time frame, and abruptness of the change from subsidence to uplift that we observe. The crustal shortening mechanism is preferred because it allows the observed abrupt uplift when an object impinges on a forearc and causes locking of a shallow segment of the interplate thrust zone.
Global patterns and sources of dissolved organic matter export to the coastal zone: Results from a spatially explicit, global model
Authors: Harrison John A. , Caraco Nina , Seitzinger Sybil P.
Published: November 2005

Here we describe, test, and apply a system of spatially explicit, global models for predicting river export of three dissolved organic matter (DOM) components: dissolved organic carbon (DOC), dissolved organic nitrogen (DON), and dissolved organic phosphorus (DOP). The DON and DOP models represent the first attempt to model DON and DOP export in a spatially explicit, global manner. DOC, DON, and DOP models explain 88%, 77%, and 91% of the variability in DOC, DON, and DOP yield (kg C, N, or P km−2 yr−1) from validation basins, respectively, and all models are relatively bias free. When applied globally, these models predict that 170 Tg C yr−1, 10 Tg N yr−1, and 0.6 Tg P yr−1 are exported by rivers to the coastal zone as DOC, DON, and DOP, respectively. Because predicted spatial patterns of export for DOC, DON, and DOP are all largely driven by water runoff, geographic distributions of high and low fluxes are fairly consistent across elements, with high fluxes of DOC, DON, and DOP generally predicted for high runoff systems and low fluxes predicted for arid systems. However, there are important regional differences in predicted rates of DOC, DON, and DOP export due to anthropogenic inputs of DON and DOP and wetland influence on DOC.
Enriched components in the Hawaiian plume: Evidence from Kahoolawe Volcano, Hawaii
Authors: Huang Shichun , Frey Frederick A. , Blichert‐Toft Janne , Fodor R. V. , Bauer Glenn R. , Xu Guangping
Published: November 2005

The geochemical differences between individual Hawaiian shields provide clues to the magma source components in the Hawaiian plume. Lavas from Koolau (Makapuu‐stage) and Kahoolawe volcanoes define the enriched, i.e., relatively high 87Sr/86Sr and low 143Nd/144Nd, extreme for Hawaiian shield lavas. There are, however, important geochemical differences between these shields; Kahoolawe lavas lack the relatively high SiO2, low CaO, and high Sr/Nb and La/Nb that are characteristic of Makapuu‐stage Koolau lavas, and they are offset from other Hawaiian shield lavas to high 87Sr/86Sr at a given 143Nd/144Nd. Consequently, a varying role for recycled plagioclase‐rich gabbro is inferred, in particular, lower amounts of the low 87Sr/86Sr component in Kahoolawe lavas. Also, lavas from Loa‐trend volcanoes, such as Kahoolawe, define trends ranging toward high 208Pb*/206Pb* and 87Sr/86Sr and low 143Nd/144Nd and 176Hf/177Hf. Such trends are consistent with variable amounts of recycled sediment sampled by Loa‐trend volcanoes, with the largest proportion in Makapuu‐stage Koolau lavas. Therefore the enriched component in the Hawaiian plume, the Koolau component, is recycled oceanic crust, which is heterogeneous because of varying proportions of sediment, basalt, and gabbro. Hawaiian shield‐stage lavas range widely in 87Sr/86Sr, 143Nd/144Nd, 176Hf/177Hf, and 206Pb/204Pb, but they have similar ratios of Sr/Nd, Nd/Hf, and Hf/Pb, each varying by a factor of <3 among the Hawaiian shields. This observation has important consequences. Namely, the similar Hf/Pb ratios are inconsistent with a two‐component (i.e., Kea and Koolau) mixing model for explaining the hyperbolic trend of 176Hf/177Hf versus 206Pb/204Pb defined by shield lavas. Such a model requires end‐members with very different Hf/Pb (a factor of 15 to 40), but this is not observed; therefore a third component must be involved. On the basis of trends of 208Pb*/206Pb* versus 87Sr/86Sr, 143Nd/144Nd, and 176Hf/177Hf, we infer that Loa and Kea trend shield lavas contain variable amounts of the Loihi source component.
Temporal and spatial variability in the composition of lavas exposed along the Western Blanco Transform Fault
Authors: Pollock Meagen A. , Klein Emily M. , Karson Jeffrey A. , Tivey Maurice A.
Published: November 2005

The northern scarp of the Western Blanco Transform (BT) Fault Zone provides a “tectonic window” into crust generated at an intermediate‐rate spreading center, exposing a ∼2000 m vertical section of lavas and dikes. The lava unit was sampled by submersible during the Blancovin dive program in 1995, recovering a total of 61 samples over vertical distances of ∼1000 m and a lateral extent of ∼13 km. Major element analyses of 40 whole rock samples exhibit typical tholeiitic fractionation trends of increasing FeO*, Na2O, and TiO2and decreasing Al2O3and CaO with decreasing MgO. The lava suite shows a considerable range in extent of crystallization, including primitive samples (Mg# 64) and evolved FeTi basalts (FeO > 12%; TiO2> 2%). On the basis of rare earth element and trace element data, all of the lavas are incompatible‐element depleted normal mid‐ocean ridge basalts (N‐MORB; La/SmN< 1). The geochemical systematics suggest that the lavas were derived from a slightly heterogeneous mantle source, and crystallization occurred in a magmatic regime of relatively low magma flux and/or high cooling rate, consistent with magmatic processes occurring along the present‐day southern Cleft Segment. The BT scarp reveals the oceanic crust in two‐dimensional space, allowing us to explore temporal and spatial relationships in the horizontal and vertical directions. As a whole, the data do not appear to form regular spatial trends; rather, primitive lavas tend to cluster shallower and toward the center of the study area, while more evolved lavas are present deeper and toward the west and east. Considered within a model for construction of the upper crust, these findings suggest that the upper lavas along the BT scarp may have been emplaced off‐axis, either by extensive off‐axis flow or off‐axis eruption, while the lower lavas represent axial flows that have subsided with time. A calculation based on an isochron model for construction of the upper crust suggests that the Cleft Segment requires at least ∼50 kyr to build the lower extrusive section, consistent to first order with independent estimates for the construction of intermediate‐spreading rate crust.
Interferometric identification of ion acoustic broadband waves in the auroral region: CLUSTER observations
Authors: Backrud M. , Tjulin A. , Vaivads A. , André M. , Fazakerley A.
Published: November 2005

We determine the phase velocity and k vector for parallel and oblique broadband extremely low frequency, ELF, waves on nightside auroral magnetic field lines at altitudes around 4.6 RE. We use internal burst mode data from the EFW electric field and wave instrument onboard the Cluster spacecraft to retrieve phase differences between the four probes of the instrument. The retrieved characteristic phase velocity is of the order of the ion acoustic speed and larger than the thermal velocity of the protons. The typical wavelength obtained from interferometry is around the proton gyro radius and always larger than the Debye length. We find that in regions with essentially no suprathermal electrons above a few tens of eV the observed broadband waves above the proton gyro frequency are consistent with upgoing ion acoustic and oblique ion acoustic waves.
Arctic Ocean change heralds North Atlantic freshening
Authors: Karcher M. , Gerdes R. , Kauker F. , Köberle C. , Yashayaev I.
Published: November 2005

A large pool of freshwater formed of ice and runoff is hosted by the Arctic Ocean. It exits through the Canadian Archipelago and Fram Strait to enter the North Atlantic deep water production regions. Using a numerical model and observations we trace a strong freshwater release to subpolar waters in the mid‐1990s. In contrast to the ice export driven 1970's ‘Great Salinity Anomaly’ its source was a large additional liquid freshwater release from the Arctic Ocean. In fact it was a consequence of a change of the Arctic Ocean's thermohaline structure in response to the very intense North Atlantic Oscillation in the early 1990s. Our results show a strong link of large‐scale Arctic Ocean changes with the freshwater flux to subpolar waters.
Array measurements of deep tremor signals in the Cascadia subduction zone
Authors: La Rocca Mario , McCausland Wendy , Galluzzo Danilo , Malone Steve , Saccorotti Gilberto , Del Pezzo Edoardo
Published: November 2005

Preliminary analysis of deep tremor recorded during July, 2004, in the Cascadia Subduction zone shows that small aperture arrays can resolve the slowness and back azimuth of seismic waves with a useful resolution. Data were collected by three dense arrays of short‐period seismometers specifically deployed in the Puget Sound area under an US‐Italy‐Canada cooperative effort. Slowness analyses at the three arrays indicate that the 2–4 Hz tremor wave‐field is composed of waves propagating with apparent velocities higher than 4 km/s. Combining this with polarisation analysis show these waves to be transverse (SH) waves. However, P‐waves, though smaller in amplitude, can be detected by different slowness values obtained for the radial and transverse components. The intersection of wave vectors determined by the back azimuth and slowness values measured at the three arrays provides a preliminary estimate of source location for a sample of the recorded deep tremor.
Oldest reliable terrestrial 40Ar‐39Ar age from pyrite crystals at Isua west Greenland
Authors: Smith Patrick E. , Evensen Norman M. , York Derek , Moorbath Stephen
Published: November 2005

Pyrite grains can act as K‐Ar time capsules, by armoring the minute inclusions hosted within the pyrite, thus preventing loss of their radiogenic argon. This pyrite clock provides the means to apply single‐crystal laser 40Ar‐39Ar dating to rocks that typically resist straightforward dating, notably sedimentary rocks. We have applied the technique to a banded iron formation from Earth's oldest sequence of sedimentary and volcanic rocks, the Isua greenstone belt of west Greenland. We find that, in spite of having been subjected to several metamorphic and metasomatic events, the mineral inclusions in pyrites from these rocks give remarkably well‐defined and reproducible ages at 3.86 ± 0.07 Ga, in agreement with previous determinations of the age of their host rocks. Moreover, the isotopic data from these pyrites yield distinct indications of inclusions giving an age of 4.31 ± 0.06 Ga, possibly providing the first direct evidence for a much earlier crust at Isua.
The Urumqi River source Glacier No. 1, Tianshan, China: Changes over the past 45 years
Authors: Ye Baisheng , Yang Daqing , Jiao Keqin , Han Tianding , Jin Zhefan , Yang Huian , Li Zhongqin
Published: November 2005

This study analyzes long‐term climate and glacier records to examine climate change and glacier response over the past 45 years in Urumqi River source region, the Tianshan Mountains of China. The results show that summer temperature and annual precipitation near the glacier increased by 0.8°C and 87 mm (19%), respectively, during the study period. The glacier continuously retreated from 1962 to 2003, with the cumulated mass balance being −10,032 mm, or 20% of the glacier volume. Annual basin runoff has significantly increased by 413 mm or 62% during 1980–2003 due to precipitation increase and enhanced glacier melt caused by summer climate warming. Both summer precipitation and temperate are negatively correlated with mass balance and positively associated with runoff. Relative to precipitation‐mass balance relation, the regression between temperature and mass balance is much stronger, indicating that summer temperature controls glacier mass balance and runoff changes.
A deep high‐resolution optical log of dust, ash, and stratigraphy in South Pole glacial ice
Authors: Bramall N. E. , Bay R. C. , Woschnagg K. , Rohde R. A. , Price P. B.
Published: November 2005

We describe a new dust logger designed to operate in water‐filled IceCube boreholes in South Pole ice, and we give examples of its performance. We recorded optical effects due to bubbles, dust, and volcanic ash in situ from ∼70 to 2100 meters. Seasonal layering in bubble concentration could also be discerned. Below ∼1300 m over the interval 25 ka to 70 ka, because of the conversion of all air bubbles to invisible hydrate crystals, and the close match between refractive indices of the surrounding ice and the water in the borehole, scattering from dust provided fine‐structure in the depth‐dependence of concentration with a resolution of <1 cm. Thin, highly absorptive horizons in the data set confirm there is significant fallout at South Pole of ash from explosive volcanic events. By locating and dating volcanic ash layers in the South Pole dust record, it may be possible to match them to volcanic layers found across Antarctica and in Greenland.
Magnetosheath variations during the storm main phase on 20 November 2003: Evidence for solar wind density control of energy transfer to the magnetosphere
Authors: Kataoka R. , Fairfield D. H. , Sibeck D. G. , Rastätter L. , Fok M.‐C. , Nagatsuma T. , Ebihara Y.
Published: November 2005

Energy transfer from the solar wind into the magnetosphere and ionosphere is controlled by the southward magnetic field in the magnetosheath which under normal high Mach number conditions is about four times the solar wind southward field. In a low Mach number regime, however, the magnetosheath compression is diminished by a low solar wind density when the magnetic field remains steady. When magnetic clouds with extremely strong magnetic field cause severe geomagnetic storms under such low Mach number conditions, the density control of the energy transfer is expected to be important in understanding ring current evolution. Here we show evidence for such a density effect using in‐situ observation by the GOES and Cluster spacecraft in the magnetosheath during the main phase of the super storm on 20 November 2003. Results from a global magnetohydrodynamic (MHD) simulation with an embedded ring current model also support this density effect.
Fire as an interactive component of dynamic vegetation models
Authors: Arora Vivek K. , Boer George J.
Published: November 2005

Fire affects ecosystems by altering both their structure and the cycling of carbon and nutrients. The emissions from fires represent an important biogeochemical pathway by which the biosphere affects climate. For climate change studies it is important to model fire as a mechanistic climate‐dependent process in dynamic global vegetation models (DGVMs) and the terrestrial ecosystem components of climate models. We expand on those current approaches which neglect disturbance by fire, which use constant specified loss rates, or which depend on simple empirical relationships, and develop a process‐based fire parameterization for use in the terrestrial ecosystem components of climate and Earth system models. The approach is straightforward and general enough to apply globally and for current and future climates. All three aspects of the fire triangle, fuel availability, the readiness of fuel to burn depending on conditions, and the presence of an ignition source, are taken into account. The approach also represents some anthropogenic effects on natural fire regimes, albeit in a simple manner. The fire parameterization is incorporated in the Canadian Terrestrial Ecosystem Model (CTEM) which simulates net primary productivity, leaf area index, and vegetation biomass. The fire parameterization generates burned area, alters vegetation biomass, and generates CO2 emissions. The parameterization is tested by comparing simulated fire return intervals and CO2 emissions with observation‐based estimates for tropical savanna, tropical humid forests, mediterranean, and boreal forest locations.
Measurement of isotopomer signatures of N2O in groundwater
Authors: Well R. , Flessa H. , Jaradat F. , Toyoda S. , Yoshida N.
Published: November 2005

N2O flux from aquifers caused by leaching of agricultural N is a poorly known component of the global anthropogenic source of this greenhouse gas. We measured isotopomer signatures of N2O (intramolecular distribution of 15N as well as conventional nitrogen and oxygen isotope ratios) in the interface region between shallow groundwater and the atmosphere in order to evaluate this technique for determining fluxes, production, reduction and the isotopomer fingerprint of N2O originating from the saturated zone. 15N‐site preference (difference in δ15N between central and peripheral N‐position) measured in the shallow groundwater of a hydromorphic soil (29 to 81‰) was distinctly larger compared to surface emitted N2O. Local and global isotopic budget calculations confirmed that the groundwater derived N2O flux of the experimental site was low compared to measured surface fluxes and suggest that 15N‐site preference might be useful for validating global estimates of groundwater emitted N2O.
Sedimentary metal ratios in the Colombia Basin as indicators for water balance change in northern South America during the past 400,000 years
Authors: Mora Germán , Martínez J. Ignacio
Published: November 2005

Recent paleoclimate reconstructions for northern South America suggest changes in moisture balance interpreted to result from shifts in the mean latitudinal position of the Intertropical Convergence Zone (ITCZ). Because most of these records only extend back to the last glacial interval, we measured metal abundances in sediments from Ocean Drilling Program Core 999A in the Caribbean Sea spanning the last 400 kyr to evaluate glacial/interglacial fluctuations in the water balance of northern South America. Variations in sedimentary Al/Ti, K/Ti, Fe/Ti, and Fe/Al ratios are interpreted to reflect changes in riverine input through the Magdalena River. The measured metal ratios show a strong 100‐kyr cyclicity, which could reflect changes in sedimentation related to sea level fluctuations or to climate. Although the variability in Fe/Ti and Fe/Al ratios points to rainfall‐induced changes in the mineralogy of the terrigenous fraction, shelf erosion induced by sea level fluctuations cannot completely be ruled out. If climate accounted for changes in the nature of the terrigenous components, then the strong 100‐kyr fluctuations in the measured metal ratios would point to the influence of high‐latitude climate on the local hydrological balance of northern South America with ice volume growth forcing a southward displacement of the ITCZ.
Polar mesosphere summer echo detection using a dynasonde
Authors: Rose Mike C. , Clilverd Mark A. , Jarvis Martin J. , Rodwell Shane
Published: November 2005

We describe a new polar mesosphere summer echo (PMSE) radar system implementation that uses a snow‐buried antenna operated with the dynasonde at Halley, Antarctica (76°S), the highest southern latitude at which any PMSE measurements have been made to date. Two 100 m2 coaxial‐collinear antenna arrays were built so that the antenna beams were colocated at 85 km altitude. Operations in PMSE mode began on 20 January 2004, close to the maximum operational frequency of the system at 28 MHz. PMSE signals were observed at the end of the Antarctic summer season in 2004 and subsequently during the austral summer of 2004/2005 at similar altitudes to PMSE observed in the Northern Hemisphere. We compare the sensitivity of the system to the well‐known mesosphere‐stratosphere‐troposphere radar at Poker Flat (65°N, 147°W, 50 MHz) and calculate a volume reflectivity at 28 MHz of η = 2.9 × 10−11 m−1, which is consistent with that determined from Northern Hemisphere radar systems operating at higher frequencies.
Role of preexisting topography and overburden on strain partitioning of oblique doubly vergent convergent wedges
Authors: Del Castello M. , McClay K. R. , Pini G. A.
Published: November 2005

Scaled sandbox modeling was used to analyze the three‐dimensional aspects of strain partitioning along obliquely convergent margins that underwent a subduction polarity reversal event. In the experiments, the first phase of shortening produced a preexisting topography that affected wedge kinematics during the second phase. Increasing degrees of obliquity during the first shortening phase produced different amounts of inherited topography and overburden, giving way to different effects on wedge response during the second phase of shortening. During the second phase the models with an inherited heavy overburden show an anomalous orientation for Riedel shears predating the development of a margin‐parallel strike‐slip fault. These shears are oriented at an angle that is higher than kinematically predicted with respect to the subduction slot, suggesting a transient rotation of the stress applied by the obliquity of subduction. In contrast, experiments with a lighter overburden do not show this inconsistency. In addition, all the models displayed an unexpectedly high accretion rate during the second phase of shortening, which we interpret to be dependent on topographical slope breaks inherited after the first phase of shortening and the critical asymmetrical architecture of doubly vergent wedges.