bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of gut microbiota and allergic reactions in BALB/c mice fed different cultivars of rice
Authors: Sonoyama Kei , Ogasawara Toru , Goto Haruka , Yoshida Tomoyo , Takemura Naoki , Fujiwara Reiko , Watanabe Jun , Ito Hiroyuki , Morita Tatsuya , Tokunaga Yoshinari , Yanagihara Tetsuji
Published: September 2009

Our preliminary clinical trial showed that consumption of cooked rice of a Japanese common cultivar Yukihikari improved atopic dermatitis associated with a suspected rice allergy, although the underlying mechanisms remain unclear. We hypothesised that the ameliorating effect of Yukihikari on atopic dermatitis is associated with the gut microbiota. BALB/c mice were fed a synthetic diet supplemented with uncooked and polished white rice powder prepared from one of four different cultivars: Yukihikari, rice A (common rice), rice B (brewery rice) and rice C (waxy rice). Denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments showed that the composition of faecal microbiota was different between mice fed Yukihikari and those fed rice A. Analysis of the 16S rRNA clone library and species-specific real-time PCR showed that the abundance ofAkkermansia muciniphila, a mucin degrader, tended to be lower in mice fed Yukihikari. The incidence of allergic diarrhoea induced by oral administration of ovalbumin in systemically immunised mice was lower in mice fed Yukihikari, albeit with no difference in serum antibodies specific to ovalbumin. In a separate experiment, serum antibody levels specific to orally administered ovalbumin were lower in mice fed Yukihikari. Additionally, the translocation of horseradish peroxidase in isolated segments of ileum and colon tended to be lower in mice fed Yukihikari, suggesting a reduction in gut permeability in mice fed Yukihikari. These data indicate that changes in the gut microbiota of mice fed Yukihikari could be advantageous in the prevention of food allergy.
PRODUCTION SYSTEM-SPECIFIC DIFFERENCES IN FARMERS' DEMAND FOR GREATER YAM (DIOSCOREA ALATA) VARIETAL ATTRIBUTES IN ORISSA STATE, INDIA
Authors: SIVAKUMAR P. SETHURAMAN , NEDUNCHEZHIYAN M. , PARAMAGURU S. , RAY R. C.
Published: September 2009

Greater yam (Dioscorea alata), a popular crop in India, is cultivated widely in Orissa state, India. In spite of the availability of several improved varieties, farmers preferred the local landraces. An investigation was carried out to identify whether the varietal preferences of yam farmers in two production systems, subsistence and commercial, were different. While the subsistence farmers demanded the yam varieties adaptable to a wide range of soils, the commercial farmers preferred the anthracnose-resistant cultivars. This study demonstrated that the farmers' varietal preferences were highly influenced by the production systems. Identifying the convergence/divergence of varietal preferences across production systems can help breeders to develop the high impact varieties.
The Nebulous Lawmaking Process in Eritrea
Authors: Weldehaimanot Simon M , Mekonnen Daniel R
Published: September 2009

This article contrasts the lawmaking process in the Eritrean transitional legal framework with experience in South Africa, which offers insightful lessons for future improvement in Eritrea. Indeed, the Eritrean lawmaking process retains many imperfections in terms of the design of the interim constitution and ensuing practice. On paper, the competence of the executive and the legislature is not clearly demarcated. Rather, it is nebulously shared between both branches, resulting inevitably in competing interests. The lawmaking process lacks democratic characteristics and defies the requirements of accountability and good governance. The practice that has followed is worse. In a country with a protracted history of executive dominance, the lawmaking competence conferred upon the executive has inexorably contributed to entrenched dictatorship. The article offers suggestions for improvement.
Legitimacy of the East African Community
Authors: Oluoch LO Wauna
Published: September 2009

The world currently has a profusion of intergovernmental organizations charged with various public functions previously reserved for states. The operations of these organizations affect the ordinary lives of individual citizens in the member states. Yet these organizations are not legitimate, based on the standard expected of a democratic state government. This article joins the chorus demanding the legitimization of international organizations that perform public functions, taking into account their peculiar circumstances and nature, and with specific reference to the East African Community. It sets out criteria for assessing legitimacy and examines the organs, functions and administration of the East African Community against those criteria. It argues that, as presently established and structured, the East African Community seriously lacks legitimacy. There is therefore an urgent need for reform, to avoid this body becoming yet another statistic of moribund regional integration schemes in Africa.
The Evolution of the Meaning(s) of Penal Servitude for Life (Life Imprisonment) in Mauritius: The Human Rights and Jurisprudential Challenges Confronted So Far and Those Ahead
Authors: Mujuzi Jamil Ddamulira
Published: September 2009

This article analyses the history of the various meanings and interpretations of the sentence of penal servitude for life in Mauritius, the human rights implications, and the likely challenges that courts will confront in interpreting new legislation. The Privy Council held in 2008 that a mandatory sentence of penal servitude for life was arbitrary and disproportionate because it violated the right to a fair trial under the constitution. However, the article argues that the Privy Council should also have found that penal servitude for life, where the offender is to be detained for the rest of his life, violates the prisoner's right not to be subjected to inhuman punishment under the constitution, as well as violating Mauritius's international human rights obligations. It recommends that Mauritian courts consult South African jurisprudence when interpreting what amount to substantial and compelling circumstances under the 2007 Criminal Procedure (Amendment) Act.
Registration and Ranking of Company Charges in Zambia
Authors:   Akalemwa wa Mubiana ni Munalula Ngenda
Published: September 2009

This article discusses the effect of the registration requirements under the Zambian Companies Act on the rules for determining priority among company charges in Zambia. In light of the Supreme Court decision inZambia National Commercial Bank Ltd v Mwila, the article also analyses the scope for applying common law rules on the ranking of charges, vis-à-vis section 101 of the Companies Act.
Mike Campbell (Pvt) Ltd et al v The Republic of Zimbabwe: Zimbabwe's Land Reform Programme Held in Breach of the SADC Treaty
Authors: Naldi Gino J
Published: September 2009

In its first judgment the South African Development Community (SADC) Tribunal had to determine whether Zimbabwe's controversial programme of land redistribution for resettlement purposes was compatible with the SADC Treaty. The tribunal provided one of the few avenues of redress for farmers deprived of their property without compensation. It held that the land reform programme breached the treaty on the grounds that the property owners had been denied access to the domestic courts, that the applicants had been victims of racial discrimination, and that the state had failed to pay compensation for the lands compulsorily acquired. While the tribunal appears to have reached the right conclusions, its reasoning could have been more persuasive. Of wider significance is the fact that the tribunal has established itself as a forum that can provide relief for human rights violations. Its finding that human rights are justiciable under the treaty is notable.
Transient flow of a viscous incompressible fluid in a circular tube after a sudden point impulse
Authors: FELDERHOF B. U.
Published: September 2009

The flow of a viscous incompressible fluid in a circular tube generated by a sudden impulse on the axis is studied on the basis of the linearized Navier–Stokes equations. A no-slip boundary condition is assumed to hold on the wall of the tube. At short time the flow is irrotational and may be described by a potential which varies with the square root of time. At later times there is a sequence of moving and decaying vortex rings. At long times the flow velocity decays with an algebraic long-time tail. The impulse generates a time-dependent pressure difference between the ends of the tube.
Instabilities of two-layer shallow-water flows with vertical shear in the rotating annulus
Authors: GULA J. , ZEITLIN V. , PLOUGONVEN R.
Published: September 2009

Being motivated by the recent experiments on instabilities of the two-layer flows in the rotating annulus with super-rotating top, we perform a full stability analysis for such system in the shallow-water approximation. We use the collocation method which is benchmarked by comparison with analytically solvable one-layer shallow-water equations linearized about a state of cyclogeostrophic equilibrium. We describe different kinds of instabilities of the cyclogeostrophically balanced state of solid-body rotation of each layer (baroclinic, Rossby–Kelvin (RK) and Kelvin–Helmholtz (KH) instabilities), and give the corresponding growth rates and the structure of the unstable modes. We obtain the full stability diagram in the space of parameters of the problem and demonstrate the existence of crossover regions where baroclinic and RK, and RK and KH instabilities, respectively, compete having similar growth rates.
Heat, salt and momentum transport in a laboratory thermohaline staircase
Authors: KRISHNAMURTI R.
Published: September 2009

Flow characteristics and fluxes in thermohaline staircases are measured in two tanks differing in aspect ratio A, where A is the ratio of tank width to fluid depth. In one tank (the ‘1 × 1’ tank) which is 30 cm deep and 30 cm wide, a staircase of one salt-finger layer and one convecting layer develops for a certain setting of the control parameters. The convecting layer has A ≃ 2. Shadowgraphs show convecting plumes that appear disorganized, and a large-scale flow never develops. Instead, the finger layer grows in height, overtakes the convecting layer and within a few days becomes one finger layer. The second tank (the ‘1 × 5’ tank) is also 30 cm deep but is 150 cm wide. For the same control parameter setting a similar staircase with a finger layer 20 cm deep and a convecting layer 10 cm deep develop. The convecting layer, with A = 15, has quite a different character. A large-scale flow develops so that the convecting layer has one cell, 10 cm deep and 150 cm wide. In this flow are large plumes which are transient and tilted; particle image velocimetry measurements of Reynolds stresses show they help to maintain the large-scale flow against viscous dissipation. Shadowgraphs show all the finger tips swept in the direction of the large-scale flow adjacent to the finger layer. Measurements show that the large-scale flow ‘collects’ the salt delivered by the many fingers so that the accumulated negative buoyancy leads to deep convection. This is a more stable arrangement, with the configuration lasting to the order of 102 days.
Infection of Mytilus edulis by the trematode Echinostephilla patellae (Digenea: Philophthalmidae)
Authors: Prinz K. , Kelly T.C. , O'Riordan R.M. , Culloty S.C.
Published: September 2009

The blue mussel Mytilus edulis is described as second intermediate host for Echinostephilla patellae from the common limpet Patella vulgata. Mussels were infected with metacercariae of E. patellae under laboratory conditions. Average infection rates increased with increasing temperature, whereas numbers of cercariae, to which individual mussels were exposed, had no effect on relative infection success. The round to slightly oval metacercariae with an average cyst diameter of 208 μm (range 186–243 μm) encysted exclusively in the foot tissue of M. edulis. Morphologically similar metacercariae were found in naturally infected mussels at sites where parasitized P. vulgata and M. edulis are sympatric. This is the first report of E. patellae in blue mussels. The detection of M. edulis being a second intermediate host is of particular interest with regard to the abundance of the parasite and host organisms in intertidal rocky shore ecosystems. The potential role of the common limpet P. vulgata as an alternative secondary host is discussed.
Nematode infection in the lizard Bogertia lutzae (Loveridge, 1941) from the Atlantic forest in north-eastern Brazil
Authors: Ávila R.W. , Anjos L.A. , Gonçalves U. , Freire E.M.X. , Almeida W.O. , da Silva R.J.
Published: September 2009

Endoparasites associated with the small bromelicolous lizard Bogertia lutzae, a poorly studied phyllodactylid inhabitant of north-eastern Brazil, were studied. Fifty-seven specimens collected from the Atlantic Forest of Alagoas state were dissected. Only one species of parasite, the nematode Spauligodon oxkutzcabiensis, was found, with a prevalence of 22.8%. The intensity of infection was 2.62 ± 1.19, and neither the prevalence nor mean intensity differed between the sexes. There was no correlation between lizard body size and intensity of infection. An aggregated pattern of distribution (D = 0.813) of S. oxkutzcabiensis was found in this lizard host population. Bogertia lutzae represents a new host recorded for S. oxkutzcabiensis, a parasite reported for the first time for Brazil.
The place of rhinoplasty in the ageing face
Authors: Rainsbury J W
Published: September 2009

Age-related changes in the skin and underlying tissues of the nose may lead to nasal obstruction or an unsatisfactory cosmetic appearance. As the UK population ages, the number of older patients seeking advice from an otolaryngologist about these problems is increasing, and many of these patients may benefit from a rhinoplasty. Quite apart from the practical considerations of operating on more delicate ageing tissues, there are a number of psychological, motivational and social issues specific to rhinoplasty in the older patient. This review discusses these issues, and aims to define the place of rhinoplasty in the ageing face.
Effect of oral tumour size on quality of life judgements by health care professionals working with head and neck cancer patients: a pilot study
Authors: Reid K , Hicks C , Herron-Marx S , Parmar S
Published: September 2009

Aim:

To investigate whether information about the size of an oral tumour influences the multi-disciplinary team's judgement about the quality of life of head and neck cancer patients.

Method:

Using a between-group design, two groups of health care professionals rated a hypothetical patient on 20 outcome variables. The patient description was identical for both groups, except for the tumour size.

Results:

Comparison of variable ratings revealed only three significant differences between the groups' predictions and no consistency within conditions, suggesting that the participants held few common assumptions about the impact of tumour size on a range of patient experiences.

Conclusion:

The lack of agreement amongst the health care professionals suggests that, where humane judgements are used in treatment decisions for head and neck cancer patients, these may be random and inconsistent. Consequently, patients should have a direct input into treatment decisions, via formalised quality of life data.
Breathing straws
Authors: Dhanasekar G , Simmen D , Briner H R
Published: September 2009

Following nasal, septal or endoscopic surgery, it is common practice to insert nasal packs in both nasal cavities to achieve haemostasis, if there has been any bleeding at the end of the procedure. However, such packs make it difficult for patients to breathe, mainly in the first post-operative night which leads to discomfort and poor sleep. To enable patients to breathe better with nasal packs in situ, we describe a simple technique using trimmed straws and wrapped Netcell® packs for post-operative care following septal surgery, rhinoplasty and endoscopic sinus surgery. These packs also assist suction of any blood or mucous from the post-nasal space.
Novel use of ultrasound-guided endo-cavitary probe to evaluate an impalpable parapharyngeal mass
Authors: Riskalla A , Arora A , Vaz F , O'Flynn P
Published: September 2009

Aim:

We present a novel, previously undescribed technique of obtaining a biopsy from an inaccessible parapharyngeal space mass.

Method:

A modified endo-cavitary ultrasound probe was utilised to obtain an intra-oral, image-guided core biopsy of a parapharyngeal tumour. The parapharyngeal mass was not accessible to percutaneous ultrasound-guided biopsy due to its anatomical location.

Conclusion:

To our knowledge, this is the first such modification of the conventional endo-cavitary probe technique described in the literature. The technique permits accurate, well controlled biopsy of lesions located high in the parapharyngeal space, under general anaesthesia.
Whistler radiation in plasmas with cylindrical magnetic field irregularities
Authors: KRAFFT C. , ZABORONKOVA T. M.
Published: September 2009

The radiation of whistler waves by linear dipole sources immersed in magnetoplasmas with cylindrical magnetic field inhomogeneities are studied. Two types of irregularities are investigated: magnetic field enhancements and depletions. A theoretical analysis is developed for comparatively weak local perturbations of the ambient magnetic field. Results are provided by numerical calculations performed for physical conditions typical of laboratory experiments involving artificially created magnetic field irregularities. It is shown that plasma regions with locally enhanced (depleted) magnetic field intensities can increase (decrease) the amplitudes of whistler waves radiated by dipole sources, regardless of their orientation with respect to the ambient magnetic field. Results are relevant to space and laboratory experiments on very low-frequency wave radiation.
Coolie Drivers Or Benevolent Paternalists? British Tea Planters in Assam and the Indenture Labour System
Authors: BEHAL RANA P.
Published: September 2009

This paper traces the evolution of the indenture labour system in the tea plantations of Assam and, simultaneously, the shaping of the attitudes of British planters towards the labour force. Also explored are: the significant fact that only a small number of British managerial personnel were in charge of a huge migrant labour force; how the need to step up tea production for the competitive world market while keeping down costs—i.e. labour costs, being the main production cost—fostered an exploitative labour system, with planters taking frequent recourse to physical and economic coercion; and the ensuing extra-legal measures needed to keep the labour force under control. The paper also demonstrates that the colonial state was in full cognizance of the injustices of the labour system. Legislation by the government had laid the foundations of the indenture system and, while there were provisions for protecting the interests of labour force, these were on the whole ignored, with the state turning a blind eye to the planters’ use of physical and other extra-legal measures. One instance involved Chief Commissioner Henry Cotton, who attacked the injustices of the system. This attack was silenced swiftly, and the stance taken by Viceroy Curzon as the incident played out is a clear pointer to the government's willingness, to side with tea-industry interests at all costs.
Temporal Justice
Authors: GOODIN ROBERT E.
Published: September 2009

Distributive justice is ordinarily calibrated in monetary terms. But money is not the only resource that matters to people. Talk of the ‘work−life balance’ points to another: time. Control over one's time, the capacity to spend it as one wishes, is another important resource; and its distribution raises another important aspect of justice. Here I describe a new method of distinguishing how much time one has discretionary control over, net of the amount it is necessary to spend in certain ways given one's circumstances. To draw out the distributive-justice implications of these calculations, I contrast the most-to-least privileged, in terms of discretionary time: a person in a dual-earner couple with no children, versus a lone mother. The magnitude of the gap between the discretionary time enjoyed by the best and worst is a measure of temporal injustice. That gap is substantially larger in some countries (such as the US and Australia) than in others (such as Finland and Sweden). Conventional welfare-state interventions – tax and transfer systems, support for child care – contribute pretty similarly to reducing that particular gap across all the countries examined. Differing practices surrounding the dissolution of marriages with children potentially makes a much bigger difference. Differing labour-market policies might make a similarly large difference yet again.
Ageing, income and living standards: evidence from the British Household Panel Survey
Authors: BERTHOUD RICHARD , BLEKESAUNE MORTEN , HANCOCK RUTH
Published: September 2009

In Britain, older people have lower average incomes and a higher risk of income poverty than the general population. Older pensioners are more likely to be in poverty than younger ones. Yet certain indicators of their living standards suggest that older people experience less hardship than expected, given their incomes. A possible explanation is that older people convert income into basic living standards at a higher rate than younger people, implying that as people age they need less income to achieve a given standard of living. Much existing evidence has been based on cross-sectional data and therefore may not be a good guide to the consequences of ageing. We use longitudinal data on people aged at least 50 years from theBritish Household Panel Surveyto investigate the effects of ageing on the relationship between standard of living, as measured by various deprivation indices, and income. We find that for most indices, ageing increases deprivation when controlling for income and other factors. The exception is a subjective index of ‘financial strain’, which appears to fall as people age. We also find evidence of cohort effects. At any given age and income, more-recently-born older people in general experience more deprivation than those born longer ago. To some extent these ageing and cohort effects balance out, which suggests that pensions do not need to change with age.
The impact of out-migration on the inter-generational support and psychological wellbeing of older adults in rural China
Authors: GUO MAN , ARANDA MARIA P. , SILVERSTEIN MERRIL
Published: September 2009

This paper examines the impact of the out-migration of adult children on older parents' inter-generational support and psychological wellbeing in rural China. The sample comprised 1,237 older Chinese people aged 60 or more years in the rural province of Anhui, China, who completed baseline and follow-up questionnaires in 2001 and 2003, respectively. The differences between older parents with and without migrant children in 2001 in their support and psychological wellbeing in 2003 were examined using independentt-tests, as were changes over the two years in support and wellbeing. Multiple regression models were used to examine the impact of baseline out-migration on the psychological wellbeing of older parents at follow-up. The results showed that, compared to parents without migrant children in 2001, the parents of migrants had significantly more monetary support, less instrumental support, and a lower level of depression in 2003. Such differences may be attributed to different support resources and health status, but the regressions revealed that when the positive effect of inter-generational support was taken into account, older parents with more migrant children tended to have significantly more depression and lower life satisfaction. The findings point to the importance of continued inter-generational support after out-migration in maintaining parental wellbeing.
An upper-level functional design ontology to support knowledge management in SME-based E-Manufacturing of mechanical products
Authors: Mosca Alessandro , Palmonari Matteo , Sartori Fabio
Published: September 2009

This paper presents a conceptual and computational framework for supporting the development of knowledge management systems based on ontology design and implementation. This framework supports enterprises involved in the design and manufacturing of complex mechanical products: in particular, we focus our attention on a network of small/medium Italian enterprises that collaborates in the production of a supermotard bike calledTerra Modena 198. Starting from some theoretical considerations about the role of ontologies in engineering design, this paper reflects on the difficulties that arise when knowledge is distributed, and misunderstanding and communication problems among partners could easily lead to errors in the final product.
Detecting similarities in antipattern ontologies using semantic social networks: implications for software project management
Authors: Settas Dimitrios L. , Sowe Sulayman K. , Stamelos Ioannis G.
Published: September 2009

Ontology has been recently proposed as an appropriate formalism to model software project management antipatterns, in order to encode antipatterns in a computer understandable form and introduce antipatterns to the Semantic Web. However, given two antipattern ontologies, the same entity can be described using different terminology. Therefore, the detection of similar antipattern ontologies is a difficult task. In this paper, we introduce a three-layered antipattern semantic social network, which involves the social network, the antipattern ontology network and the concept network. Social Network Analysis (SNA) techniques can be used to assist software project managers in finding similar antipattern ontologies. For this purpose, SNA measures are extracted from one layer of the semantic social network to another and this knowledge is used to infer new links between antipattern ontologies. The level of uncertainty associated with each new link is represented using Bayesian Networks (BNs). Furthermore, BNs address the issue of quantifying the uncertainty of the data collected regarding antipattern ontologies for the purposes of the conducted analysis. Finally, BNs are used to augment SNA by taking into account meta-information in their calculations. Hence, other knowledge not included in the social network can be used in order to search the social network for further inference. The benefits of using an antipattern semantic social network are illustrated using an example community of software project management antipattern ontologies.
Ontologies of engineering knowledge: general structure and the case of Software Engineering
Authors: Sicilia Miguel-Angel , García-Barriocanal Elena , Sánchez-Alonso Salvador , Rodríguez-García Daniel
Published: September 2009

Engineering knowledge is a specific kind of knowledge that is oriented to the production of particular classes of artifacts, is typically related to disciplined design methods, and takes place in tool-intensive contexts. As a consequence, representing engineering knowledge requires the elaboration of complex models that combine functional and structural representations of the resulting artifacts with process and methodological knowledge. The different categories used in the engineering domain vary in their status and in the way they should be manipulated when building applications that support engineering processes. These categories include artifacts, activities, methods and models. This paper surveys existing models of engineering knowledge and discusses an upper ontology that abstracts the categories that crosscut different engineering domains. Such an upper model can be reused for particular engineering disciplines. The process of creating such elaborations is reported on the particular case study of Software Engineering as a concrete application example.
No evidence of transmission of H5N1 highly pathogenic avian influenza to humans after unprotected contact with infected wild swans
Authors: WALLENSTEN A. , SALTER M. , BENNETT S. , BROWN I. , HOSCHLER K. , OLIVER I.
Published: September 2009

Highly pathogenic avian influenza (HPAI) subtype H5N1 remains a public health threat as long as it circulates in wild and domestic birds. Information on the transmissibility of H5N1 HPAI from wild birds is needed for evidence-based public health advice. We investigated if transmission of H5N1 HPAI had taken place in people that had unprotected contact with infected wild mute swans during an incident at the Abbotsbury Swannery in Dorset, England. Thirteen people who had been exposed to infected swans were contacted and actively followed up for symptoms. Serology was taken after 30 days. We did not find evidence of transmission of H5N1 HPAI to humans during the incident. The incident provided a rare opportunity to study the transmissibility of the virus from wild birds to humans.
A new multiplex PCR for differential identification ofShigella flexneriandShigella sonneiand detection ofShigellavirulence determinants
Authors: FARFÁN M. J. , GARAY T. A. , PRADO C. A. , FILLIOL I. , ULLOA M. T. , TORO C. S.
Published: September 2009

Most of the multiplex PCR (mPCR) used to identifyShigellado not discriminate betweenShigellaspecies or serotypes. We designed a mPCR to differentiate betweenS. flexneriandS. sonneistrains based on the detection of markers associated with theshepathogenicity island described inShigella. In addition, specific primers were included to detect theShigellavirulence determinants ShET-1 and ShET-2 enterotoxin genes. The analysis of 304Shigellastrains from Chile and 79Shigellastrains from other geographic locations indicated that the mPCR described here detected allShigellaspecies and specifically differentiatedS. flexneriandS. sonnei. The technique was sensitive, reproducible, specific and simple to perform, providing a new tool with the potential to be employed for epidemiological and diagnostic purposes.
NifHgene diversity and expression in a microbial mat community on the McMurdo Ice Shelf, Antarctica
Authors: Jungblut Anne D. , Neilan Brett A.
Published: September 2009

N2-fixation is an important mechanism in microbial mats of the McMurdo Ice Shelf as nitrogen sources are limited. Here we applied molecular analyses of the N2-fixing diversity in cyanobacterial dominated microbial mats in a meltwater pond, known as Orange Pond, on the McMurdo Ice Shelf. Phylogenetic analyses ofnifHgenes andnifHgene transcripts were performed in association with acetylene reduction assay measurements. Eighteen phylotypes with the highest similarities to cyanobacteria, firmicutes, beta-, gamma- and deltaproteobacteria, spirochaetes and verrumicrobia were identified. All cyanobacterialnifHphylotypes grouped solely in the genusNostocspp. Clone-library analysis ofnifHgene transcripts only identified sequences with a highest match toNostocspp. and acetylene reduction activity was identified in the presence of light and absence of 3-(3,4-dichlorophenyl)-1,1-dimethyl urea. These molecular results indicate that a variety of bacterial phyla possess the ability to fix nitrogen. However, under the tested conditions the only organisms actively transcribingnifHgenes wereNostocspp. This underlines the importance ofNostocfor the nitrogen budget on the McMurdo Ice Shelf.
Dike propagation through layered rocks
Authors: Taisne B. , Jaupart C.
Published: September 2009

Dike penetration through a succession of upper crustal layers with different densities is studied with a new numerical code. For an individual layer to significantly affect dike ascent, its thickness must be of order 1 when scaled to the characteristic length‐scale for the inflated nose region that develops below the dike tip. This characteristic length is L* ∝ (μQ)1/6 (G/(1 − ν))1/2 (Δρg)−2/3, where μ and Δρ are the viscosity and buoyancy of magma, G and ν are elastic moduli for the encasing rocks, Q is the magma flow rate and g gravity. For basaltic dikes, L* is ≈1 km, which is of the same order of magnitude as the typical thickness of sedimentary strata and volcanic deposits. In such conditions, dike ascent proceeds irregularly, with large changes of velocity and width at an interface. Scaling laws for the ascent rate and dike width are derived. Penetration through low‐density layers is determined by a local buoyancy balance in the inflated nose region of the dike, independently of the total buoyancy of the magma column between source and tip. In such conditions, a dike develops an internal overpressure that may be large enough to generate a horizontally propagating sill. For this to occur, the thickness of the low‐density layers must exceed a threshold value, which depends only on the rock strength and on the average negative buoyancy of magma. For basaltic melt, we estimate that this threshold thickness cannot be less than about 700 m and is 2 km on average.
Characteristics of high‐frequency gravity waves generated by tropical deep convection: Case studies
Authors: Dutta Gopa , Ajay Kumar M. C. , Vinay Kumar P. , Venkat Ratnam M. , Chandrashekar M. , Shibagaki Y. , Salauddin M. , Basha H. A.
Published: September 2009

High‐frequency gravity waves generated by tropical deep convection play a major role in shaping the general circulation of the middle atmosphere. Special experiments were conducted to capture two convective events on 16 May and 5 June 2006 using VHF radar located at Gadanki (13.5°N, 79.2°E), a tropical Indian station. Control day observations were also made for necessary comparisons. Background wind and temperature information was obtained by GPS radiosonde flights launched from the same site. This work has utilized these valuable data sets to delineate characteristics of convectively generated gravity waves. A superposition of gravity waves is observed with different scales after the deep convective events. Vertical wave number spectra of radial velocities show steeper slopes and higher power spectral densities during convection which slowly reduce to their normal values. The present case studies suggest the mechanical oscillator mechanism to be a major source of convective gravity wave generation in the tropics. Estimates of vertical wind variances and momentum fluxes of short‐period (<2 h) wind fluctuations show large enhancements on convective days in comparison to control days. The momentum flux frequency spectra revealed a higher contribution of 30–65 min wave periods to the mean profile in the lower stratosphere. The wavelet transform momentum flux spectra displayed the temporal variability and discretization of the gravity wave momentum fluxes in frequency and time.
Comparison of ultra‐low‐frequency waves at Mercury under northward and southward IMF
Authors: Boardsen Scott A. , Slavin James A. , Anderson Brian J. , Korth Haje , Solomon Sean C.
Published: September 2009

Narrow‐band ultra‐low‐frequency (ULF) waves at frequencies greater than the He+ cyclotron frequency (fcHe+) were detected during MESSENGER's first two Mercury flybys. The waves were observed primarily between closest approach (CA) and the outbound magnetopause. The magnetosphere was very quiet during the first flyby (M1) and highly disturbed during the second flyby (M2); that ULF waves were observed during both flybys despite these different magnetospheric conditions is remarkable. The wave frequency structure in the boundary layer (BL) was similar between M1 and M2. Between CA and the BL, for M1 the wave frequency rose systematically from fcHe+ to the proton cyclotron frequency (fcH+), while during M2 two frequency bands were observed, one near the He++ cyclotron frequency and one near fcH+. The main difference in the waves between the two flybys, apart from their frequency structure, was their power, which was 4 to 5 times larger during M2 than during M1.
First Satellite Observations of Meteoric Smoke in the Middle Atmosphere
Authors: Hervig Mark E. , Gordley Larry L. , Deaver Lance E. , Siskind David E. , Stevens Michael H. , Russell James M. , Bailey Scott M. , Megner Linda , Bardeen Charles G.
Published: September 2009

This work describes the first remote observations of meteoric smoke particles (MSPs) from satellite, by the Solar Occultation For Ice Experiment (SOFIE) onboard the Aeronomy of Ice in the Mesosphere (AIM) platform. The measurements show a layer of MSPs from roughly 35 to 85 km altitude, and indicate a seasonal cycle with reduced MSP abundance during polar summer. The measurements agree favorably with model results, and confirm that MSP transport by the global meridional circulation causes the dramatic reduction in MSPs during polar summer. These new observations represent a major advance in our ability to understand a hitherto poorly characterized class of particles that are thought to be important in numerous atmospheric and terrestrial processes.
Radial and latitudinal gradients of anomalous cosmic ray oxygen in the inner heliosphere
Authors: Cummings A. C. , Tranquille C. , Marsden R. G. , Mewaldt R. A. , Stone E. C.
Published: September 2009

We use data from the Ulysses, Advanced Composition Explorer, and Solar Terrestrial Relations Observatory spacecraft to determine the radial and latitudinal gradients of anomalous cosmic ray oxygen in two energy ranges from 4.5–15.6 MeV/nuc in the inner heliosphere for the first time during an A<0 part of the solar cycle. Using measurements from early 2007 to mid‐2008, we find that the radial gradient is ∼48 ± 13%/AU, consistent with previous inferences for A<0 and larger than that determined in the inner heliosphere for A>0. The latitudinal gradient is consistent with zero and in the range −0.3 to 0.4%/degree, suggesting that during A<0 these particles are not able to propagate into the inner heliosphere by rapid drift along the heliospheric current sheet if the tilt of the sheet is as large as 30 degrees.
Forecasting change of the magnetic field using core surface flows and ensemble Kalman filtering
Authors: Beggan C. D. , Whaler K. A.
Published: September 2009

Accurate forecasting of the change of the Earth's internal magnetic field over short intervals of time (e.g., less than five years) has many applications for government, academic and commercial users. Forecasting can be achieved by making a number of reasonable assumptions about how the main field interacts with the flow in the liquid outer core. In particular, the magnetic field can be considered to be entrained in the large scale flow along the core‐mantle boundary surface over short time periods, giving rise to measurable change at the Earth's surface. The observed change (or secular variation) at or above the surface of the Earth can thus be inverted to produce flow models; these can be used to propagate fluid parcels threaded by the field forwards in time to forecast the non‐linear change of the magnetic field. In addition to prediction of field change by flow models, it would be advantageous to include observations of the field from satellite measurements or ground‐based observatories. We therefore present a method using Ensemble Kalman Filtering (EnKF) to produce an optimal assimilation between magnetic field change as forecast from core flow models and direct observations of the field. We show, by assuming a steady flow and assimilating field observations annually, it is possible to produce a forecast over five years with less than 30nT root mean square difference from the ‘true’ field – within an assumed error budget. The EnKF method also allows sensitivity analysis of the field models to noise and uncertainty within the physical representation.
Impact of the QBO on surface winter climate
Authors: Marshall Andrew G. , Scaife Adam A.
Published: September 2009

The European winter surface climate response to the Quasi‐Biennial Oscillation (QBO) and its dependence on stratospheric resolution is cleanly assessed in idealized seasonal hindcasts with two versions of the Hadley Centre's atmospheric general circulation model. The standard 38‐level version extends to an altitude of 39 km while the extended 60‐level version has enhanced stratospheric resolution and reaches 84‐km altitude. We show that both models generate a realistic stratospheric polar and surface European Arctic Oscillation (AO) response to the QBO for winter hindcasts initialized on 1 December and suggest that the better representation of the QBO in the L60 model will lead to improved forecasts at seasonal‐to‐multiannual timescales.
Rainfall estimation from satellite passive microwave observations in the range 89 GHz to 190 GHz
Authors: Di Tomaso E. , Romano F. , Cuomo V.
Published: September 2009

The aim of the present work is to improve the current state of rainfall estimation by proposing a procedure based entirely on the observations made by the US Advanced Microwave Sounding Unit/B (AMSU/B) on board the National Oceanic and Atmospheric Administration (NOAA) satellites. The procedure does not require the integration of additional sensors which could deteriorate the overall spatial and temporal resolution. It exploits both the radiometric observations made at 89 and 150 GHz (window channels) and the ones made in the 183 GHz water vapor band (opaque channels). In particular, the differences between the measurements of some of the AMSU/B channels are analyzed through radiative transfer simulations for the estimation of precipitation over both land and water surfaces and are related to rain rate values in different atmospheric scenarios. The algorithm estimates exhibit a very good agreement with ground‐based (both radar and rain gauge) observations in the detection of rainfall and a reasonably good estimation of rain rate values. The probability of detection of precipitation is 75% and 90% for rain rates greater than 1 mm/h and 5 mm/h, respectively. Furthermore, due to the use of both window and opaque channels, the proposed procedure is able to retrieve light rain and not to misidentify snow‐covered surfaces as rain.
Cloud influence on and response to seasonal Arctic sea ice loss
Authors: Kay Jennifer E. , Gettelman Andrew
Published: September 2009

Recent declines in Arctic sea ice extent provide new opportunities to assess cloud influence on and response to seasonal sea ice loss. This study combines unique satellite observations with complementary data sets to document Arctic cloud and atmospheric structure during summer and early fall. The analysis focuses on 2006–2008, a period over which ice extent plummeted to record levels, substantial variability in atmospheric circulation patterns occurred, and spaceborne radar and lidar observations of vertical cloud structure became available. The observations show that large‐scale atmospheric circulation patterns, near‐surface static stability, and surface conditions control Arctic cloud cover during the melt season. While no summer cloud response to sea ice loss was found, low clouds did form over newly open water during early fall. This seasonal variation in the cloud response to sea ice loss can be explained by near‐surface static stability and air‐sea temperature gradients. During summer, temperature inversions and weak air‐sea temperature gradients limit atmosphere‐ocean coupling. In contrast, relatively low static stability and strong air‐sea gradients during early fall permit upward turbulent fluxes of moisture and heat and increased low cloud formation over newly open water. Because of their seasonal timing, cloud changes resulting from sea ice loss play a minor role in regulating ice‐albedo feedbacks during summer, but may contribute to a cloud‐ice feedback during early fall.
Gravity wave activity during stratospheric sudden warmings in the 2007–2008 Northern Hemisphere winter
Authors: Wang Ling , Alexander M. Joan
Published: September 2009

We use temperature retrievals from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC)/Formosa Satellite Mission 3 (FORMOSAT‐3) and Challenging Minisatellite Payload (CHAMP) Global Positioning Satellite (GPS) radio occultation profiles and independent temperature retrievals from the EOS satellite High Resolution Dynamics Limb Sounder (HIRDLS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) aboard the TIMED satellite to investigate stratospheric sudden warming (SSW) events and the accompanying gravity wave (GW) temperature amplitudes in the 2007–2008 Northern Hemisphere winter. We identify four SSW events (including a major one) occurring from late January to late February in 2008. We detect enhanced GW amplitudes in the stratosphere and subdued GW amplitudes in the lower mesosphere during the warming events. The timing of GW enhancement/suppression and warming/cooling events was generally close (within a couple days). We also find that stratospheric GW amplitudes were generally larger at the polar vortex edge and smaller in the vortex core and outside of the vortex and that stratospheric GW amplitudes were generally small over the North Pacific. Using a simplified GW dispersion relation and a GW ray‐tracing experiment, we demonstrate that the enhanced GW amplitudes in the stratosphere during SSWs could be explained largely by GW propagation considerations. The existence of GW critical levels (the level at which the background wind is the same as the GW phase speed) near the stratopause during SSWs would block propagation of GWs into the mesosphere and thus could lead to the observed subdued GW activity in the lower mesosphere. Since this is the first study to analyze the COSMIC and CHAMP GPS temperature retrievals up to 60 km in altitude, we compare the GPS analysis with those from HIRDLS and SABER measurements. We find that the temporal variability of zonal mean temperatures derived from the GPS data is reasonable up to ∼60 km in altitude, but the GPS data were less sensitive to SSWs than the HIRDLS and SABER data. GW analysis from GPS is consistent with HIRDLS up to ∼35 km in altitude, but it seems that the small‐scale variability at higher altitudes revealed in the GPS data is questionable.
Middle atmospheric thermal structure obtained from Rayleigh lidar and TIMED/SABER observations: A comparative study
Authors: Guharay A. , Nath D. , Pant P. , Pande B. , Russell J. M. , Pandey K.
Published: September 2009

A novel measurement of seasonal variability of the middle atmospheric thermal structure has been carried out by comparing ground‐based lidar and space‐based TIMED/SABER observations from a low‐latitude station, Gadanki (13.5°N, 79.2°E), India. Lidar temperature has been cross‐verified by retrieving from Cooperative Institute for Research in the Atmosphere's (CIRA) CIRA‐86 model and SABER observation density and pressure values independently. Observed results are also compared with CIRA‐86 model data. Model data show significant difference with observed ones. Observed results match nicely among themselves throughout the year, which further validates the SABER data at low latitude with an average deviation of ∼2 K in 35–75 km altitude range with respect to the Rayleigh lidar. Seasonal pattern of adiabatic lapse rate all over the altitude range reveals a statically stable atmosphere during the observation period. Stratopause temperature shows semiannual oscillation (SAO) in seasonal pattern of variation, which matches with previous observations from low‐latitude stations.