bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevention of postpartum hemorrhage with misoprostol
Authors: Alfirevic Z. , Blum J. , Walraven G. , Weeks A. , Winikoff B.
Published: October 2007

As a stable, orally active and cheap uterotonic, misoprostol would appear ideally suited to the prevention of postpartum hemorrhage (PPH) in the developing world. Following numerous clinical trials, it appears that misoprostol prophylaxis using an oral or sublingual dose of 600 μg is more effective than placebo at preventing PPH in community births (relative risk 0.59, 95% confidence intervals 0.41–0.84), but not in hospital settings (RR 1.23, 95% CI 0.86–1.74). It is, however, not as effective as injectible oxytocin (RR 1.34, 95% CI 1.16 to 1.55). Misoprostol is therefore indicated for prevention of PPH in settings where injectible conventional uterotonics are not available. In the event of continued hemorrhage, a minimum of 2 h should lapse after the original dose before a second dose is given. If the initial dose was associated with pyrexia or marked shivering, at least 6 h should lapse before the second dose is given.
Reliability of studies of iodine intake and recommendations for number of samples in groups and in individuals
Authors: Andersen Stig , Karmisholt Jesper , Pedersen Klaus M. , Laurberg Peter
Published: October 2007

The iodine intake level in a population is determined in cross-sectional studies. Urinary iodine varies considerably and the reliability of studies of iodine nutrition and the number of samples needed is unsettled. We performed a longitudinal study of sixteen healthy men living in an area of mild to moderate iodine deficiency. Iodine and creatinine concentrations were measured in spot urine samples collected monthly for 13 months. From these data we calculated the number of urine samples needed to determine the iodine excretion level for crude urinary iodine and for 24 h iodine excretion estimated from age- and gender-specific creatinine excretions. We found that mean urinary iodine excretion varied from 30 to 87 μg/l (31 to 91 μg/24 h). Sample iodine varied from 10 to 260 μg/l (20 to 161 μg/24 h). Crude urinary iodine varied more than estimated 24 h iodine excretion (population standard deviation 32v. 26; individual standard deviation 29v. 21; Bartlett's test,P < 0·01 for both). The number of spot urine samples needed to estimate the iodine level in a population with 95 % confidence within a precision range of ± 10 % was about 125 (100 when using estimated 24 h iodine excretions), and within a precision range of ± 5 % was about 500 (400). A precision range of ± 20 % in an individual required twelve urine samples or more (seven when using estimated 24 h iodine excretions). In conclusion, estimating population iodine excretion requires 100–500 spot urine samples for each group or subgroup. Less than ten urine samples in an individual may be misleading.
Moderate exercise reduces serum triacylglycerol concentrations but does not affect pre-heparin lipoprotein lipase concentrations after a moderate-fat meal in young men
Authors: Miyashita Masashi , Tokuyama Kumpei
Published: October 2007

Aerobic exercise has been shown to lower postprandial TAG concentrations after a meal(s) of high-fat content. This study examined the effects of moderate-intensity cycling on postprandial TAG concentrations and pre-heparin lipoprotein lipase concentrations after subjects consumed a meal of moderate-fat content (45 % of total energy). Twelve male subjects, aged 24 (sem 1) years, completed two 2 d trials (exercise and control) at least 1 week apart in a randomised, repeated measures design. On day 1, subjects either cycled for 30 min at 65 % of maximum heart rate in the afternoon or rested (no exercise). On day 2 of both trials, after an overnight stay with an 11 h fast, subjects consumed a test meal of moderate-fat content (0·61 g fat, 1·34 g carbohydrate, 0·37 g protein and 51 kJ energy/kg body mass) for breakfast. Blood samples were collected at baseline (before the exercise or at an equivalent time-point during the control trial on day 1), in the fasted state (0 h) and at 2, 4 and 6 h postprandially on day 2. The total and incremental areas under the serum TAG concentration v. time curve were 30 % (P = 0·039) and 33 % (P = 0·012) lower on the exercise trial compared with the control trial, respectively. Serum pre-heparin lipoprotein lipase concentrations did not differ between the exercise and control trials. These findings demonstrate that 30 min of moderate-intensity cycling performed the day before a meal of moderate-fat content is effective at lowering postprandial serum TAG concentrations but does not affect serum pre-heparin lipoprotein lipase concentrations in young men.
Effect of high hydrostatic pressure and whey proteins on the disruption of casein micelle isolates
Authors: Harte Federico M , Gurram Subba Rao , Luedecke Lloyd O , Swanson Barry G , Barbosa-Cánovas Gustavo V
Published: October 2007

High hydrostatic pressure disruption of casein micelle isolates was studied by analytical ultracentrifugation and transmission electron microscopy. Casein micelles were isolated from skim milk and subjected to combinations of thermal treatment (85°C, 20 min) and high hydrostatic pressure (up to 676 MPa) with and without whey protein added. High hydrostatic pressure promoted extensive disruption of the casein micelles in the 250 to 310 MPa pressure range. At pressures greater than 310 MPa no further disruption was observed. The addition of whey protein to casein micelle isolates protected the micelles from high hydrostatic pressure induced disruption only when the mix was thermally processed before pressure treatment. The more whey protein was added (up to 5 g/l) the more the protection against high hydrostatic pressure induced micelle disruption was observed in thermally treated samples subjected to 310 MPa.
Ectoine as a natural component of food: detection in red smear cheeses
Authors: Klein Julia , Schwarz Thomas , Lentzen Georg
Published: October 2007

Ectoine is a compatible solute accumulated in halophilic bacteria in response to high salt concentrations and offers protection from osmotic stress. The occurrence of compatible solutes is widespread among bacteria, yet ectoine has never been detected in foods. The use of an ectoine producing microorganism (Brevibacterium linens) in the surface ripening of red smear cheeses led to the question whether ectoine can be found in cheese. Therefore we examined samples from a variety of cheese manufacturers and different types of red smear cheeses for the presence of ectoine using HPLC and HPLC/MS analysis. Ectoine solely appears in the rind and was detected up to 178 mg/200 g red smear cheese, depending on several factors like ripening status and conditions throughout the cheese production process (e.g. salt concentrations of used brine baths).
Effects of high-pressure treatment on free fatty acids release during ripening of ewes' milk cheese
Authors: Juan Bibiana , Ferragut Victoria , Buffa Martin , Guamis Buenaventura , Trujillo Antonio-José
Published: October 2007

The free fatty acid (FFA) profile of high pressure treated ewes' milk cheeses were studied to assess the effect of pressure treatment on cheese lipolysis. Cheeses were treated at 200, 300, 400 or 500 MPa (2P to 5P) at two stages of ripening (after 1 and 15 days of manufacturing; P1 and P15) and FFA were assayed at 1, 15 and 60 d ripening. On the first day of ripening, 3P1-cheeses showed levels of FFA twice that of the control cheeses. However, no significant differences were found between 3P1 and control cheeses at 60 d ripening. On the contrary, 4P1 and 5P1-cheeses had the lowest total FFA levels. The point at which pressure treatment was applied influenced the FFA profile of cheeses; cheeses pressurized at pressures <400 MPa on the first day of ripening were more similar to untreated cheeses than their homologues treated at 15 d.
Compositional, microbiological, biochemical, volatile profile and sensory characterization of four Italian semi-hard goats' cheeses
Authors: Cagno Raffaella Di , Evan Miracle R , Angelis Maria De , Minervini Fabio , Rizzello Carlo G , Anne Drake Mary , Fox Patrick F , Gobbetti Marco
Published: October 2007

Four semi-hard Italian goats' milk cheeses, Flor di Capra (FC), Caprino di Cavalese (CC), Caprino di Valsassina (CV) and Capritilla (C), were compared for compositional, microbiological, biochemical, volatile profile and sensory characteristics. Mean values for the gross composition in part differed between cheeses. At the end of ripening, cheeses contained 7·98−8·51 log10 cfu/g of non-starter lactic acid bacteria. Lactobacillus paracasei, Lb. casei and Lb. plantarum were dominant in almost all cheeses. As shown by the Principal Component Analysis of RP-FPLC data for the pH 4·6-soluble fractions and by the determination of free amino acids, secondary proteolysis of CC and CV mainly differed from the other two cheeses. A total of 72 volatile components were identified by steam distillation-extraction followed by gas chromatography-mass spectrometry. Free fatty acids and esters qualitatively and quantitatively differentiated the profile of CV and CC, respectively. The lowest concentrations of volatile components characterized FC. Descriptive sensory analysis using 17 flavour attributes was carried out by a trained panel. Different flavour attributes distinguished the four goats' cheeses and relationships were found with volatile components, biochemical characteristics and technology.
Violence, Reconstruction and Islamic Reform—Stories from the Muslim ‘Ghetto’
Authors: JASANI RUBINA
Published: October 2007

This paper is a critique of popular and academic assumptions about the Muslim ‘community’ and Islamist organizations, especially in the context of displacement and reconstruction after the 2002 riots in Ahmedabad, western India. It explores the internal politics of Jamaat-led organizations and the engagement of survivors with ideas of reform and piety. Contesting contemporary understandings of reformist Jamaats, I argue that the growing influence of the latter organizations had little co-relation with their resettlement plans and policies. The reconstruction patterns were more closely linked to the history of labour migration to the city, and the subsequent movement of violence-affected people from the mill areas to larger Muslim ghettoes. My ethnography shows how the survivors strategically engaged with reform initiatives and negotiated with local Islamist organizations for ‘safe housing’. By illustrating certain ambiguities within the everyday practices of Islam, my paper also problematizes notions of ‘piety’ and ‘agency’, primarily after people's experiences of communal violence.
The Changing Perspectives of Three Muslim Men on the Question of Saint Worship over a 10-Year Period in Gujarat, Western India
Authors: SIMPSON EDWARD
Published: October 2007

In many religious traditions, those who mediate relations between men and gods are often the focus of controversy and moral ambiguity. The ethnography in this paper outlines a number of perspectives on the role of such intermediaries (here ‘saints’) in Muslim society in western India. In the South Asian literature, historians have provided a thorough treatment of the doctrinal history and content of these debates. However, very little attention has been paid to how living individuals interpret and rehearse these debates in practice. The examination of the changing perspectives of three Muslim men on the question of saint worship over a 10 year period reveals the following. First, an individual's relationship with ‘saints’ is often determined primarily by social context rather than simply by doctrinal allegiance or the compulsions of particular ‘beliefs’. Second, discourses of religious reform are also powerful social objects that can be used as political instruments for purposes other than simply refining the religious practices of a community. Finally, many commonplace assumptions in the literature—notably on the nature of belief and the significance of doctrinal divisions among Muslims—do not withstand ethnographic scrutiny.
Islamic Feminism in India: Indian Muslim Women Activists and the Reform of Muslim Personal Law
Authors: VATUK SYLVIA
Published: October 2007

I describe here a nascent ‘Islamic feminist’ movement in India, dedicated to the goal of achieving gender equity under Muslim Personal Law. In justifying their demands, these women activists refer neither to the Indian Constitution nor to the universalistic human rights principles that guide secular feminists campaigning for passage of a gender-neutral uniform civil code of personal law, but rather to the authority of the Qur'an—which, they claim, grants Muslim women numerous rights that in practice are routinely denied them. They accuse the male ‘ulamaof foisting ‘patriarchal’ interpretations of the Qur'an on the unlettered Muslim masses and assert their right to read the Qur'an for themselves and interpret it in a woman-friendly way. Their activities reflect an increasing ‘fragmentation of religious authority’ in the globalizing Muslim world, associated with the spread of mass education, new forms of media and transport and a mobile labour force, in which clerical claims to exclusive authoritative knowledge are being questioned by a wide variety of new voices, women's among them. Whether it can ultimately succeed is an open question but the movement is clearly having an impact, even on the clerical establishment itself, insofar as the legal issues it considers most pressing for women are concerned.
Identification and localization of a putative ATP-binding cassette transporter in sea lice (Lepeophtheirus salmonis) and host Atlantic salmon (Salmo salar)
Authors: TRIBBLE N. D. , BURKA J. F. , KIBENGE F. S. B. , WRIGHT G. M.
Published: October 2007

Some members of the ABC-transporter superfamily, such as P-glycoprotein and the multidrug resistance associated protein, may confer resistance to the avermectin subclass of macrocyclic lactones. The aim of this study was to examine the presence of ABC transporters in both sea lice (Lepeophtheirus salmonis) and its Atlantic salmon host (Salmo salar) using monoclonal antibodies (C219 and JSB-1, with high selectivity for P-gp) and a new polyclonal antibody (SL0525) generated against a putative sea louse ABC transporter. The antibody raised to SL0525 did not react with rat P-gp, suggesting that an ABC transporter, not necessarily P-gp, was isolated. C219 was the only antibody to localize P-gp in all 3 salmon tissues (intestine, kidney and liver). American lobster (Homarus americanus) was used as a reference crustacean forL. salmonisimmunostaining reactions and showed positive staining in the hepatopancreatic and intestinal tissues with all 3 antibodies. TheL. salmonisshowed positive staining in the intestinal epithelial lining with all antibodies. This report represents the first documented evidence for the expression of ABC transporters inL. salmonis, its Atlantic salmon host, and the American lobster.
Introduction to Two Unpublished Lectures by Leo Strauss
Authors: Tarcov Nathan
Published: October 2007

These two lectures by Leo Strauss, “What Can We Learn from Political Theory?” delivered in July 1942, and “The Re-education of Axis Countries Concerning the Jews,” delivered November 7, 1943, include not only Strauss's most elaborate statement about the relation of political philosophy and political practice (in the first), but what may well be his fullest written public statements about matters of contemporary foreign policy. Both lectures obviously were carefully considered, composed, and corrected, but Strauss did not attempt to publish either. He may have had second thoughts about some of the arguments he advanced in these lectures, or he may simply have chosen to concentrate his literary efforts elsewhere. Other lectures he prepared during this period but did not publish himself have since been published: “The Living Issues of German Postwar Philosophy,” delivered April 1940 at Syracuse University, and “Reason and Revelation,” delivered January 1948 at Hartford Theological Seminary, both in Heinrich Meier, Leo Strauss and the Theologico-Political Problem (Cambridge University Press, 2006); “German Nihilism,” delivered to the New School's General Seminar February 26, 1941, is in Interpretation 26:3 (Spring 1999).
Divided Publius: Democracy, Federalism, and the Cultivation of Public Sentiment
Authors: Smith Troy E.
Published: October 2007

Alexander Hamilton and James Madison agreed in the Federalist that the Constitution authorizes both political and judicial processes to define and safeguard the boundaries of federalism, but disagreed on public opinion's role in a republic and how to cultivate public sentiment for the Constitution. Hamilton preferred resolving intergovernmental disputes via political and public processes because public endorsement would legitimize broad national powers. Madison favored building public sentiment for the Constitution through strict limits on the national government enforced in part by the judiciary. He thought resolving intergovernmental disputes via public processes would confirm widespread suspicions of imperium in imperio and might provoke a popular backlash that would upset the constitutional equilibrium and undermine even legitimate national powers. This difference foreshadows Hamilton and Madison's later constitutional disagreements, reveals fundamental ambiguities in America's federal system, and confirms the need to consider how institutions and policies affect public sentiment for the constitutional order.
“We should see certain things yet, let us hope and believe”: Technology, Sex, and Politics in Mark Twain's Connecticut Yankee
Authors: Dobski Bernard J. , Kleinerman Benjamin A.
Published: October 2007

Through his modern “Yankee,” Mark Twain reveals to his readers the underlying desire to overcome the very material world he seems to want to instantiate. Although the Yankee seems a modern man who simply wants to create the conditions in Arthurian England by which his body will be most comfortable, both his zeal for this project and the trajectory of his soul's course during the book betray an underlying hope to overcome his “mortal coil” through first technological and then political projects. In charting the impetus and evolution of the Yankee's psychology for us, Twain teaches us much about the nature of the “modern project”—its underlying hopes and its potential for dangerous, even totalitarian, excesses. As appealing as the starkly contrasting Arthurians might be, given this insight, Twain does not ultimately endorse this position but shows that its explicit claim does not ultimately satisfy our desire for noninstrumental goods.
Salmonella in healthy pigs: prevalence, serotype diversity and antimicrobial resistance observed during 1998–1999 and 2004–2005 in Japan
Authors: FUTAGAWA-SAITO K. , HIRATSUKA S. , KAMIBEPPU M. , HIROSAWA T. , OYABU K. , FUKUYASU T.
Published: October 2007

To determine prevalence, serotype diversity and antimicrobial resistance of Salmonella in healthy pigs, faecal samples from 6771 pigs on 73 farms collected during 1998–1999 and 2004–2005 were examined. Salmonella isolates were serotyped and tested for susceptibility to 22 antimicrobials: benzylpenicillin, ampicillin, amoxicillin, cefazolin, cephaloridine, gentamicin, kanamycin, streptomycin, fradiomycin, colistin, tetracycline, chlortetracycline, oxytetracycline, chloramphenicol, thiamphenicol, sulfadimethoxine, sulfamethoxazole, sulfamethoxypyridazine, trimethoprim, sulfamethoxazole/trimethoprim, norfloxacin and ofloxacin. Farm-level and pig-level Salmonella prevalences were 35·5% and 2·2% in 1998–1999, and 35·7% and 3·3% in 2004–2005. Prevalence by growth stage was 2·4% for sows, 3·3% for weaned pigs, 2·7% for fattening pigs and 3·8% for finishing pigs. The predominant serotypes identified were Agona (28·4%), Typhimurium (17·9%) and Infantis (16·4%) in 1998–1999, and Typhimurium (32·5%), Anatum (24·6%) and Infantis (13·5%) in 2004–2005. Compared with the 1998–1999 isolates, the 2004–2005 isolates showed significantly higher rates of resistance to all the antimicrobials except tetracyclines (P<0·01 to P<0·05) and resistance to ⩾2 antimicrobials [19·4% (13/67) vs. 39·7% (50/126), P<0·01]. This study provides national estimates of Salmonella prevalence in healthy pigs of different growth stages in Japan.
Use of a molecular epidemiological database to track human rabies case histories in South Africa
Authors: COETZEE P. , WEYER J. , PAWESKA J. T. , BURT F. J. , MARKOTTER W. , NEL L. H.
Published: October 2007

The KwaZulu Natal and Eastern Cape provinces of South Africa have experienced a serious dog rabies epidemic over the past three decades. Towards a better understanding of this epidemic, we have previously analysed nucleotide sequences of 142 rabies virus specimens that were obtained from these regions during 2003–2004 and provided a molecular description of the geographical distribution of rabies viral variants in the affected provinces. Here, as an extension, we studied five human cases that occurred during 2002–2003 and demonstrated the use of the sequence database in tracking unknown human rabies case histories. We were able to identify the geographical origin of viruses responsible for each human infection and in one case obtained evidence that suggested a non-bite transmission of rabies virus from an infected dog to a child. We argue for the value of this information in surveillance and epidemiological study and in the follow-up and management of potential exposures.
Excess salmonellosis in women in the United States: 1968–2000
Authors: RELLER M. E. , TAUXE R. V. , KALISH L. A. , MØLBAK K.
Published: October 2007

We describe recent epidemiological changes in salmonellosis. Linking 1968–2000 NationalSalmonellaSurveillance System to census data, we calculated population-based age- and sex-stratified rates of non-urinary salmonellosis for the top 30 non-typhoidal serotypes. Using 1996–1997, 1998–1999, and 2000–2001 population-based FoodNet surveys, we compared reported diarrhoea, medical visits, and stool cultures. Despite an overall female-to-male incidence rate ratio (FMRR) of 0·99, the sex-specific burden of salmonellosis varied by age (<5 years FMRR 0·92; 5–19 years 0·85; 20–39 years 1·09; 40–59 years 1·23, and ⩾60 years 1·08) and serotype (FMRR range 0·87 for Mississippi to 1·25 for Senftenberg). Serotype-specific FMRRs and median age (range 2 years for Derby to 29 years for Senftenberg) were related (correlation 0·76,P<0·0001). Recently, the relative burden of salmonellosis in women has increased. FoodNet data suggest that this change is real rather than due to differential reporting. Excess salmonellosis in women may reflect differences in exposure or biological susceptibility.
Materials used for seed storage containers: response to Gómez-Campo [Seed Science Research16, 291–294 (2006)]
Authors: Walters Christina
Published: October 2007

Efficient seed storage is a shared concern among the growing number of seed banks established for crop improvement or ex situ conservation. Container properties greatly affect seed interactions with the environment and the overall cost and success of seed banking operations. Several material properties contribute to their suitability as seed containers. This paper provides a consolidated list of water vapour permeability properties of thermal plastics commonly used for packaging. Composite packages with layers of film with different properties provide distinct advantages to seed banks. Different seed banks must rank the importance of the various factors depending on their mission and resources. Once the risks, costs and benefits are weighed, an appropriate strategy can be developed that addresses a seed bank's specific needs. Because there are many problems and several solutions, it is likely that strategies will vary among seed banks. This response details variables to consider when selecting seed storage packages, and focuses on water diffusion rates of packages with different compositions. A ‘moisture audit’ will help seed bank operators make informed decisions about packaging.
Seed dormancy in red rice. XII: Population-based analysis of dry-afterripening with a hydrotime model
Authors: Gianinetti Alberto , Alan Cohn Marc
Published: October 2007

Red rice (Oryza sativaL.) dispersal units (florets) were dry-afterripened for 0–8 weeks and subsequently incubated at 30°C in polyethylene glycol (PEG) solutions with water potentials from 0 to − 1.6 MPa. Germination percentages and rates increased with dry-afterripening and water potential of the incubation medium. The seed population exhibited a normal distribution of base water potentials (Ψb, i.e. minimum water potential allowing germination) among individual seeds, characterized by three parameters: the hydrotime constant (θH), the mean base water potential (Ψb) and the standard deviation of the base water potential distribution (σΨb). Changes in germination during afterripening could be described by modifications of such parameters, particularlyΨb, which was employed to derive an index, DH(ARX = Ψb(ARX) − Ψb(ARN), where DH(ARX) represents a measure of dormancy of the seed population (in MPa) based on the hydrotime model,Ψb(ARX) is the mean base water potential of the seed population at any afterripening timeX, andΨb(ARN) is the mean water potential of the non-dormant (fully afterripened) population. The introduction of this index permitted interpretation of afterripening as a measurable reduction in the dormancy status of the seed, with progressive acquisition of both full germinative capacity and maximum germination rate, as anticipated by the hydrotime model. Moreover, secondary dormancy was induced proportionally to the reduction in water potential in the dark. Susceptibility to secondary dormancy induction was defined through DI(ARX), an index analogous to DH(ARX). These indices revealed that, in red rice, both breaking of primary dormancy and the inducibility of secondary dormancy followed decay kinetics with different sensitivities to the duration of dry storage.
Display matters
Authors: Molotch Harvey
Published: October 2007

Garrow and Shove use objects to reveal larger social and cultural patterns, in this case – most ambitiously – epistemological and methodological practices of their respective disciplines. I think it works and I agree with their support for future interdisciplinary object-swapping.
Artefacts between disciplines. Response to responses
Authors: Garrow Duncan , Shove Elizabeth
Published: October 2007

As is often the way, a ‘finished’ article disguises aspects of its own production and gives an overly orderly account of theoretical and methodological moves which were not especially planned. In responding to our commentators and in coming clean about our own working methods we have some confessions to make. In making these admissions we continue what has by now become a conversation about matters of interdisciplinarity and about our approach to the axe and the toothbrush.
Visions of archaeology. An interview with Tim Murray
Authors: Lucas Gavin
Published: October 2007

Tim Murray has occupied a unique, and at times contentious, position within Australian archaeology. His primary interests in the history of archaeology and theory made him ‘a luxury no department could afford’ in the fieldwork-dominated atmosphere of 1980s Australian archaeology, though he has since gone on to establish himself as a leading figure in both Australia and the international community. The politics of archaeology has also been a central element of his thought through both his historical work on race and his engagment with indigenous communities in Tasmania. The breadth of Murray's interests and contributions to the discipline of archaeology emerges very clearly from this interview and highlights issues that remain of central importance to the discipline.
Evidence of ventilation changes in the Arabian Sea during the late Quaternary: Implication for denitrification and nitrous oxide emission
Authors: Pichevin Laetitia , Bard Edouard , Martinez Philippe , Billy Isabelle
Published: October 2007

Modern seawater profiles of oxygen, nitrate deficit, and nitrogen isotopes reveal the spatial decoupling of summer monsoon‐related productivity and denitrification maxima in the Arabian Sea (AS) and raise the possibility that winter monsoon and/or ventilation play a crucial role in modulating denitrification in the northeastern AS, both today and through the past. A new high‐resolution 50‐ka record of δ15N from the Pakistan margin is compared to five other denitrification records distributed across the AS. This regional comparison unveils the persistence of east‐west heterogeneities in denitrification intensity across millennial‐scale climate shifts and throughout the Holocene. The oxygen minimum zone (OMZ) experienced east‐west swings across Termination I and throughout the Holocene. Probable causes are (1) changes in ventilation due to millennial‐scale variations in Antarctic Intermediate Water formation and (2) postglacial reorganization of intermediate circulation in the northeastern AS following sea level rise. Whereas denitrification in the world's OMZs, including the western AS, gradually declined following the deglacial maximum (10−9 ka BP), the northeastern AS record clearly witnesses increasing denitrification from about 8 ka BP. This would have impacted the global Holocene climate through sustained N2O production and marine nitrogen loss.
Extreme ductility of feldspar aggregates—Melt‐enhanced grain boundary sliding and creep failure: Rheological implications for felsic lower crust
Authors: Závada Prokop , Schulmann Karel , Konopásek Jiří , Ulrich Stanislav , Lexa Ondrej
Published: October 2007

High‐grade orthogneisses from granulite‐bearing lower crustal unit show extreme finite strains of both K‐feldspar and plagioclase with respect to weakly deformed quartz aggregates. K‐feldspar aggregate in the most intensely deformed sample shows interstitial grains of quartz and albite, which also mark some intragranular fractures within K‐feldspar grains. Both interstitial grains and fractures are oriented mostly perpendicular to the sample stretching lineation. Quartz and albite grains within K‐feldspar bands are interpreted as crystallized from interstitial melt and the petrology study shows that the melt was produced by a metamorphic reaction in plagioclase‐mica bands. Thermodynamic Perple_X modeling shows that melt volume increase was negligible and melt amount was too small to generate considerable melt overpressure for calculated PT conditions. It is therefore suggested that dilation of K‐feldspar aggregates and fracturing of its grains represent a final creep failure state, which resulted from the cavitation process accompanying grain boundary sliding controlled diffusion creep. The consequence of cavitation‐driven dilation of K‐feldspar aggregates is the local underpressure resulting in infiltration of melt from plagioclase bands. Analogy with metallurgy experiments shows that the cavitation process, exclusively developed in cryptoperthitic K‐feldspar, can be attributed to its lower purity compared to more pure plagioclase. Contrasting rheological behavior of feldspars with respect to quartz prior to fracturing is attributed to different deformation mechanisms. Feldspars appear weaker due to grain boundary sliding accommodated by coupled melt‐enhanced diffusion creep along grain boundaries and dislocation creep within grains, in contrast to quartz deforming via grain boundary migration accommodated dislocation creep.
Ion and electron accelerations by large‐scale shear Alfvén waves via cross‐field instabilities
Authors: Khazanov Igor , Singh Nagendra
Published: October 2007

Using two‐dimensional particle‐in‐cell simulations we study the linear and nonlinear effects of a large‐scale shear Alfvén wave (LS‐SAW) propagating parallel to the ambient magnetic field Bo. We demonstrate that ion polarization drift in the propagating SAW drives cross‐field instability (CFI) by ion‐electron coupling and produces electrostatic (ES) waves, which accelerate electrons parallel and ions perpendicular to Bo. Even though the large‐scale SAW has no parallel electric field E∥, the E∥ of the ES wave fields embedded in LS‐SAW provide a novel acceleration mechanism for the electrons moving with the group velocity of the LS‐SAW. Examining data from satellite observations, we suggest that the mechanism of CFI for plasma acceleration/heating powered by LS‐SAWs is distinctly possible on auroral field lines.
Ground magnetometer observation of a cross‐phase reversal at a steep plasmapause
Authors: Kale Z. C. , Mann I. R. , Waters C. L. , Goldstein J. , Menk F. W. , Ozeke L. G.
Published: October 2007

The cross‐phase technique employs ground‐based magnetometer data in order to determine the resonance frequency of a geomagnetic field line. Typically, a positive cross‐phase maximum identifies the field line resonance frequency, but occasionally, a negative cross‐phase maximum is observed and is believed to be a feature of the steep density gradient at the plasmapause. For a few hours during the local morning of 14 May 2001 the cross‐phase maximum, observed using two pairs of ground‐based magnetometer stations from the European sector, with midpoints at L = 3.16 and L = 3.34, reversed polarity from positive to negative. All other British Geological Survey, Sub‐Auroral Magnetometer Network, and International Monitor for Auroral Geomagnetic Effects (IMAGE) magnetometer array station pairs examined between L = 2.39 and L = 6.54 showed a positive cross‐phase maximum throughout the day. The Imager for Magnetopause‐to‐Aurora Global Exploration (IMAGE) satellite made an excellent close magnetic conjunction with these ground‐based magnetometer arrays on this day, and data from the IMAGE Radio Plasma Imager instrument show a very steep plasmapause in this region during this UT interval. IMAGE Extreme Ultraviolet Imager global plasmasphere images show that the plasmapause moved outward through the day, passing through the region of the observed negative cross‐phase maxima. This rare observation of a negative cross‐phase maximum occurs at the location of a plasmapause with a gradient steeper than r−8 and thus is in agreement with theory. The two cross‐phase peak polarity reversals are explained by the evolution of the local density profile.
Transform margin of the northern Levant, eastern Mediterranean: From formation to reactivation
Authors: Schattner U. , Ben‐Avraham Z.
Published: October 2007

The Levant continental margin, eastern Mediterranean, is usually defined as a passive margin that developed between the late Paleozoic‐early mid‐Mesozoic. Previous studies suggest that the margin is composed of two segments with different structural characteristics. The southern segment (south of the Carmel Structure) was formed by rifting, whereas the origin of the northern segment is not known. The present study focuses on the northern segment, which is a key for understanding the tectonic history of the eastern Mediterranean. Investigation is carried out offshore on two scales: (1) deep crustal observations, analysis of seismic refraction and magnetic data and their comparison with other continental margins worldwide; and (2) shallow crustal‐scale observations of recent tectonic deformations, based on multichannel and single‐channel seismic reflection profiles. Integration of the deep and shallow observations with reevaluation of geological data onland show strong structural resemblance between the northern Levant segment and other transform margins. A modified scenario is suggested for the formation and development of the Levant basin and its margins, combining all previous studies into one simple picture, where a signature of older structures on more recent features is evident. Located in the midst of the progressive Afro‐Eurasian collision, the northern Levant presents a unique lifecycle for transform margins worldwide, from formation to reactivation.
On the reduced moment in the transient regime of homogeneous nucleation
Authors: Bartell Lawrence S. , Wu David T.
Published: October 2007

One of the parameters characterizing the evolution of nucleation in the transient regime is the so-called reduced moment, a dimensionless quantity. This parameter describes the steepness with which the nucleation rate approaches its steady state. Until recently, very little had been known about this parameter in real systems, although a widely quoted 1969 theory [D. Kashchiev, Surf. Sci. 14, 209 (1969)] existed that formally described nucleation in the transient regime. This theory has been shown to be incorrect in its implication about the reduced moment. Molecular dynamics simulations have recently greatly clarified what happens in the transient regime. It turns out that the reduced moment depends strongly on the size of the nucleus under consideration, and, for a rapidly quenched liquid, it substantially exceeds unity for small nuclei but approaches unity as nuclei increases in size. The objective of this paper is to illustrate the behavior of the reduced moment and to show how this behavior is a natural consequence of the kinetics of the nucleation process.
Relativistic effects in the intermolecular interaction-induced nuclear magnetic resonance parameters of xenon dimer
Authors: Hanni Matti , Lantto Perttu , Iliaš Miroslav , Jensen Hans Jørgen Aagaard , Vaara Juha
Published: October 2007

Relativistic effects on the Xe129 nuclear magnetic resonance shielding and Xe131 nuclear quadrupole coupling (NQC) tensors are examined in the weakly bound Xe2 system at different levels of theory including the relativistic four-component Dirac-Hartree-Fock (DHF) method. The intermolecular interaction-induced binary chemical shift δ, the anisotropy of the shielding tensor Δσ, and the NQC constant along the internuclear axis χ‖ are calculated as a function of the internuclear distance. DHF shielding calculations are carried out using gauge-including atomic orbitals. For comparison, the full leading-order one-electron Breit-Pauli perturbation theory (BPPT) is applied using a common gauge origin. Electron correlation effects are studied at the nonrelativistic (NR) coupled-cluster singles and doubles with perturbational triples [CCSD(T)] level of theory. The fully relativistic second-order Møller-Plesset many-body perturbation (DMP2) theory is used to examine the cross coupling between correlation and relativity on NQC. The same is investigated for δ and Δσ by BPPT with a density functional theory model. A semiquantitative agreement between the BPPT and DHF binary property curves is obtained for δ and Δσ in Xe2. For these properties, the currently most complete theoretical description is obtained by a piecewise approximation where the uncorrelated relativistic DHF results obtained close to the basis-set limit are corrected, on the one hand, for NR correlation effects and, on the other hand, for the BPPT-based cross coupling of relativity and correlation. For χ‖, the fully relativistic DMP2 results obtain a correction for NR correlation effects beyond MP2. The computed temperature dependence of the second virial coefficient of the Xe129 nuclear shielding is compared to experiment in Xe gas. Our best results, obtained with the piecewise approximation for the binary chemical shift combined with the previously published state of the art theoretical potential energy curve for Xe2, are in excellent agreement with the experiment for the first time.
Effect of laser beam filamentation on plasma wave localization and electron heating
Authors: Sharma R. P. , Sharma Prerana , Chauhan P. K.
Published: October 2007

This paper presents the ponderomotive filamentation (single hot spot) of a laser beam, propagating in homogeneous plasma in a nonparaxial region. Electron plasma wave coupling in these filaments has been studied. It is found that initially launched weak plasma wave (small amplitude) gets excited and becomes highly localized (wave packet) with a broad spectrum. By expanding the eikonal and other relevant quantities up to the fourth power of r, it is observed that the focusing of the laser beams becomes fast in the nonparaxial region. The uneven focusing/defocusing of the axial and off-axial rays leads the formation of the splitted profile of laser beams in the plasma. The effects of wave particle interaction are also included in this formalism. The simulation result confirms the presence of chaotic fields, and the interaction of these fields with electrons, leads to velocity space diffusion. The stochasticity in the system is also verified by estimating the Lypunov exponent by slightly varying the laser beam power. The energy of the accelerated electrons on account of the laser beam and plasma wave interaction has been calculated by using the distribution function. For typical laser beam and plasma parameters with wavelength (λ=1064nm), power flux (1016Wcm−2), and initial temperature (Te=2.5keV), the elevated electron temperature was found to be around 4.5keV, after passing through one wave packet.
The velocity field and instability of rotating duct flow
Authors: Qin Zhaohui , Pletcher Richard H.
Published: October 2007

The velocity field and instability of the flow in a rotating square duct was investigated. The velocity field was obtained for Ekman numbers less than 1∕16 by combining a linear Stewartson layer solution, a nonlinear Ekman layer solution, and a local similarity assumption. The transition of the secondary-flow pattern from one pair of vortices to two pairs of vortices was studied with linear stability analysis. The resultant eigenvalue problem was solved numerically. The onset of the instability of the Ekman layer was also studied and found to be relevant to the type A and type B waves. The present theory was compared with the experimental results of Smirnov and Yurkin [Mekh. Zh. Gaza (Fluid Mechanics) 6, 24 (1983)]. The critical rotation numbers for marginal stability of both the Stewartson layer and the Ekman layer were found to be in good agreement with the measurements. The experiments of Döbner [Ph.D. dissertion, Technische Huchschule, Dormstadt (1959)] also revealed a boundary in the parameter space corresponding to the sudden change of the slopes of the drag curves, which was found at least partially related to the wavy instability of the Stewartson layer. A quasigeostrophic method was used to include the effects of Ekman friction in the instability formula. The critical rotation numbers obtained were in qualitative agreement with experimental data. Another phenomenon the experiments discovered was the pulsation of the four-vortex pattern as a certain critical Reynolds number was exceeded. This phenomenon has not yet been explained by the present analysis.
Scalar fields coupled to gravity in (3+1) dimensions: Static spherically symmetric stiff matter solutions
Authors: Bilge A. H. , Daghan D.
Published: October 2007

Einstein’s field equations for a spherically symmetric metric and a massless scalar field source are reduced to a system effectively of second order in time for the metric function μ. The solutions of this system split into two classes that we called the positive and negative branches, corresponding to scalar fields with spacelike and timelike gradients. Static solutions for the positive branch are well known, but the proof that μ=0 is a global attractor for the region μs+μ>0, μ<1∕2 is given for completeness. The negative branch of static solutions have the interpretation of a perfect fluid with pressure equal to mass density, called “stiff matter.” The main result of the paper is the characterization of static solutions of the negative branch by phase plane analysis. We prove that the solution μ=1∕4 is a global attractor for the region where μs+μ>0 and μ<1∕2. Two first integrals, one of which reducing to the solution μ=1∕4 in the static case, are also presented.
Chaotic oscillations in a map-based model of neural activity
Authors: Courbage M. , Nekorkin V. I. , Vdovin L. V.
Published: October 2007

We propose a discrete time dynamical system (a map) as a phenomenological model of excitable and spiking-bursting neurons. The model is a discontinuous two-dimensional map. We find conditions under which this map has an invariant region on the phase plane, containing a chaotic attractor. This attractor creates chaotic spiking-bursting oscillations of the model. We also show various regimes of other neural activities (subthreshold oscillations, phasic spiking, etc.) derived from the proposed model.
Benchmark full configuration interaction and equation-of-motion coupled-cluster model with single and double substitutions for ionized systems results for prototypical charge transfer systems: Noncovalent ionized dimers
Authors: Pieniazek Piotr A. , Arnstein Stephen A. , Bradforth Stephen E. , Krylov Anna I. , Sherrill C. David
Published: October 2007

Benchmark full configuration interaction and equation-of-motion coupled-cluster model with single and double substitutions for ionized systems (EOM-IP-CCSD) results are presented for prototypical charge transfer species. EOM-IP-CCSD describes these doublet systems based on the closed-shell reference and thus avoids the doublet instability problem. The studied quantities are associated with the quality of the potential energy surface (PES) along the charge transfer coordinate and distribution of the charge between fragments. It is found that EOM-IP-CCSD is capable of describing accurately both the charge-localized and charge-delocalized systems, yielding accurate charge distributions and energies. This is in stark contrast with the methods based on the open-shell reference, which overlocalize the charge and produce a PES cusp when the fragments are indistinguishable.
Size-dependent dynamics in excited states of gold clusters: From oscillatory motion to photoinduced melting
Authors: Stanzel Jörg , Burmeister Florian , Neeb Matthias , Eberhardt Wolfgang , Mitrić Roland , Bürgel Christian , Bonačić-Koutecký Vlasta
Published: October 2007

Femtosecond time resolved photoelectron spectroscopy in combination with direct ab initio molecular dynamics “on the fly” based on density functional theory has been used to study the relaxation dynamics of optically excited states in small mass selected anionic gold clusters (Aun−; n=5–8). The nature of the dynamics strongly depends on the cluster size and structure. Oscillatory wavepacket motion (Au5−), a long lived excited state (Au6−), as well as photoinduced melting (Au7−,Au8−) is observed in real time. This illustrates nonscalable properties of excited states in clusters in the size regime, in which each atom counts.
An attenuated total reflectance far-UV spectrometer
Authors: Higashi Noboru , Ikehata Akifumi , Ozaki Yukihiro
Published: October 2007

An ultraviolet spectrometer based on attenuated total reflection (ATR) has been developed and tested for liquid water (light and heavy water) in the wavelength range from 140to300nm, which includes the far ultraviolet (FUV) region. One of the principal limitations of FUV transmission spectra is the strong absorption of the solvent itself. High absorptivity of the n→σ* transition in water molecule has thus far prevented meaningful spectral measurements of aqueous solutions in the wavelength region under 170nm. Our technique uses the evanescent wave created through total reflection when light is passed through an internal reflection element (IRE) in contact with the sample. Since the evanescent field is used as an optical path length, the method allows spectral measurements favorably comparable with that of transmittance method with a shorter path length than the wavelength of FUV light. In this study, we have designed an original miniature IRE probe made of sapphire that allows detection of the whole n→σ* transition absorption band of water down to 140nm. The obtained ATR-FUV spectra closely match calculations based on the Fresnel formula. It is also confirmed that this spectrometer is equally effective for spectral measurements of nonaqueous solvents with significant absorptivities in the FUV region.